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Atomic physics experiments with cooled stored ions
This presentation contains examples of recent atomic physics experiments with stored and cooled ion beams from the CRYRING facility in Stockholm. One of these experiments uses the high luminosity of a cooled MeV proton beam in a He COLTRIMS apparatus (COLd supersonic He gas-jet Target for Recoil Ion Momentum Spectroscopy) for measuring correlation effects in transfer ionization. Another class of
Reinhold Schuch
Experiments in atomic and applied physics using synchrotron radiation
A diverse program in atomic and applied physics using x rays produced at the X-26 beam line at the Brookhaven National Synchrotron Light Source is in progress. The atomic physics program studies the properties of multiply-ionized atoms using the x rays for photo-excitation and ionization of neutral atoms and ion beams. The applied physics program builds on the techniques and results of the atomic physics work to develop new analytical techniques for elemental and chemical characterization of materials. The results are then used for a general experimental program in biomedical sciences, geo- and cosmochemistry, and materials sciences. The present status of the program is illustrated by describing selected experiments. Prospects for development of new experimental capabilities are discussed in terms of a heavy ion storage ring for atomic physics experiments and the feasibility of photoelectron microscopy for high spatial resolution analytical work. 21 refs., 11 figs., 2 tabs.
Jones, K.W.
Precise Atomic and Nuclear Physics Experiments with Trapped ^21Na
NASA Astrophysics Data System (ADS)
We have recently observed 40,000 trapped ^21Na atoms in our experiment at the LBNL 88'' Cyclotron. Our bigger improved traps are due to redesign of our production target and oven assembly, yielding brighter atomic beams from our Zeeman-slowing apparatus. We are currently refining our technique to measure the 1.9 GHz ground state hyperfine splitting of ^21Na. Using a pulsed trap-pump-probe scheme, we anticipate a precision better than 100 Hz with our current trap sizes and based on studies using stable ^23Na. We have observed the ? ^+ from our trapped atoms using an in-vacuum plastic scintillator, and also the ? and ? backgrounds present in our trapping chamber. These measurements will guide several planned improvements to our apparatus to achieve larger traps and cleaner ? signals. We estimate that 100,000 trapped ^21Na atoms will be necessary for a precise 1% measurement of the parity violating beta decay asymmetry parameter, which would probe for possible right-handed charged electroweak currents. Current status and data will be presented. Be there or be square. physics1.berkeley.edu/research/ freedman/webpages/laser_trapping.html>our experiment
Vetter, P. A.; Freedman, S. J.; Fujikawa, B. K.; Gwinner, G.; Rowe, M. A.; Shang, S. Q.; Wasserman, E. G.
Modern Experiments on Atom-Surface Casimir Physics
\\u000a In this chapter we review past and current experimental approaches to measuring the long-range interaction between atoms and\\u000a surfaces, the so-called Casimir-Polder force. These experiments demonstrate the importance of going beyond the perfect conductor\\u000a approximation and stipulate the relevance of the Dzyaloshinskii-Lifshitz-Pitaevskii theory. We discuss recent generalizations\\u000a of that theory, that include higher multipole polarizabilities, and present a list of
Maarten DeKieviet; Ulrich D. Jentschura; Grzegorz ?ach
Versatile single-chip event sequencer for atomic physics experiments
NASA Astrophysics Data System (ADS)
A very inexpensive dsPIC microcontroller with internal 32-bit counters is used to produce a flexible timing signal generator with up to 16 TTL-compatible digital outputs, with a time resolution and accuracy of 50 ns. This time resolution is easily sufficient for event sequencing in typical experiments involving cold atoms or laser spectroscopy. This single-chip device is capable of triggered operation and can also function as a sweeping delay generator. With one additional chip it can also concurrently produce accurately timed analog ramps, and another one-chip addition allows real-time control from an external computer. Compared to an FPGA-based digital pattern generator, this design is slower but simpler and more flexible, and it can be reprogrammed using ordinary `C' code without special knowledge. I will also describe the use of the same microcontroller with additional hardware to implement a digital lock-in amplifier and PID controller for laser locking, including a simple graphics-based control unit. This work is supported in part by the NSF.
Eyler, Edward
Atomic physics experiments with photon and ion beams
The experiments investigated the feasibility of: (1) producing multiply-charged argon ions (up to 7+) at very low energies in quantities sufficient for experimental purposes, (2) using ion trap techniques for further study of the ions and repetitive photoionization to achieve higher charge states, and (3) using a VUV spectrometer to study fluorescent radiation emitted from the ions.
Jones, K.W.; Johnson, B.M.; Meron, M.
Enhancing the Undergraduate Experience: Atomic and Nuclear Physics Experiments at AN Accelerator Facility
In this paper we will discuss experiments performed using an accelerated ion beam incident on selected targets. Some of these were: 1) Measuring Rutherford scattering and\\/or non-Rutherford nature of scattering as a function of scattering angle, energy of the ion beam and atomic number 2) Verifying theoretical prediction of the kinematical scattering factor by measuring the scattered ion energy 3)
Rahul Mehta; Stephen R. Addison; Jerome L. Duggan
In this paper we will discuss experiments performed using an accelerated ion beam incident on selected targets. Some of these were: 1) Measuring Rutherford scattering and?or non-Rutherford nature of scattering as a function of scattering angle, energy of the ion beam and atomic number 2) Verifying theoretical prediction of the kinematical scattering factor by measuring the scattered ion energy 3)
Rahul Mehta; Stephen R. Addison; Jerome L. Duggan
Laser experiments with single atoms as a test of basic physics
Two experiments with single atoms are reviewed. In the first experiment, the interaction of a single Rydberg atom with a single mode of an electromagnetic field was investigated. The quantum collapse and revivals of the atomic inversion predicted by the Jaynes-Cummings model were demonstrated for the first time. In the second experiment, a single atomic ion stored in a radio-frequency
F. Diedrich; Gerhard Rempe; Joachim Krause; M. O. Scully; H. Walther
Several atomic-physics issues connected with the use of neutral beams in fusion experiments
Energetic neutral beams are used for heating and diagnostics in present magnetic fusion experiments. They are also being considered for use in future large experiments. Atomic physics issues are important for both the production of the neutral beams and the interaction of the beams and the plasma. Interest in neutral beams based on negative hydrogen ions is growing, largely based on advances in producing high current ion sources. An extension of the negative ion approach has been the suggestion to use negative ions of Z > 1 elements, such as carbon and oxygen, to form high power neutral beams for plasma heating.
Post, D.E.; Grisham, L.R.; Fonck, R.J.
NASA Technical Reports Server (NTRS)
A symposium on atomic and molecular physics was held on November 18, 2005 at Goddard Space Flight Center. There were a number of talks through the day on various topics such as threshold law of ionization, scattering of electrons from atoms and molecules, muonic physics, positron physics, Rydberg states etc. The conference was attended by a number of physicists from all over the world.
Bhatia, Anand K.
National Technical Information Service (NTIS)
The purpose of the report is to describe activities and current problems in the field of atomic and molecular physics, and it is hoped that such description, including some outline of trends and needs, will be helpful to administrators of science. Another...
Theoretical atomic collision physics
The theoretical atomic physics at Rice University focuses on obtaining a better understanding of the mechanisms that control inelastic collisions between excited atoms and atoms, molecules and ions. Particular attention is given to systems and processes that are of potential importance to advanced energy technologies. In the current year, significant progress has been made in quantitative studies of: quenching of low-Rydberg Na atoms in thermal energy collisions with He, Ne and Ar atoms; selective excitation resulting from charge transfer in collisions of highly stripped ions of He, Li, C, and with Li, Na and He atoms and H{sub 2} molecules at keV energies; differential elastic and single, and double electron transfer in He{sup ++} collisions with He at keV energies; inelastic electron-transfer in ultra-low-energy-energy (T=8 to 80K) collisions between {sup 3}He{sup +} and {sup 4}He and {sup 4}He{sup +} and {sup 3}He; a formalism for ionization by electron impact of ions in dense, high temperature plasmas.
Lane, N.F. (Rice Univ., Houston, TX (USA) Rice Univ., Houston, TX (USA). Quantum Inst.)
Physics through the 1990s: Atomic, molecular and optical physics
NASA Technical Reports Server (NTRS)
The volume presents a program of research initiatives in atomic, molecular, and optical physics. The current state of atomic, molecular, and optical physics in the US is examined with respect to demographics, education patterns, applications, and the US economy. Recommendations are made for each field, with discussions of their histories and the relevance of the research to government agencies. The section on atomic physics includes atomic theory, structure, and dynamics; accelerator-based atomic physics; and large facilities. The section on molecular physics includes spectroscopy, scattering theory and experiment, and the dynamics of chemical reactions. The section on optical physics discusses lasers, laser spectroscopy, and quantum optics and coherence. A section elucidates interfaces between the three fields and astrophysics, condensed matter physics, surface science, plasma physics, atmospheric physics, and nuclear physics. Another section shows applications of the three fields in ultra-precise measurements, fusion, national security, materials, medicine, and other topics.
National Technical Information Service (NTIS)
Construction is beginning on an atom interferometer (a device which interferes atom waves). Fabricated metal transmissions gratings will be used as optical elements for the matter waves. Atom interferometers should be useful in studies of atomic propertie...
D. E. Pritchard
Atomic Physics with Positronium
NASA Astrophysics Data System (ADS)
Positronium, the metastable hydrogen-like bound state between an electron and its antiparticle, the positron, is a leptonic atomic system whose properties may be studied using laser spectroscopy in much the same way as for any other atomic system. However, such measurements are complicated by the difficulties associated with producing these short-lived atoms in sufficient quantities. The introduction of positron trapping techniques [1] has made it possible to produce intense bursts of slow positrons with spatiotemporal densities approaching � 10^20 e^+cm-2s-1 [2]. By implanting these positrons into various materials we may produce short bursts of positronium atoms that are well suited to pulsed laser spectroscopy, and that we have used to perform a variety of laser-Ps experiments [3] as well as measurements of Ps-Ps interactions [4]. In this presentation I shall outline the techniques we have used to do so, and describe how this work fits into our long-term goal of producing a Bose-Einstein condensate of positronium [5]. A condensate of this sort would provide a nearly ideal weakly interacting system of fundamental interest that could be used for precision spectroscopy, and may one day form the basis of a positronium annihilation gamma ray laser [6]. [4pt] [1] C. M. Surko and R. G. Greaves, Phys. Plasmas 11, 2333 (2004).[0pt] [2] D. B. Cassidy, S. H. M. Deng, R. G. Greaves and A. P. Mills Jr., Rev. Sci. Instrum. 77, 073106 (2006).[0pt] [3] D.B. Cassidy, et al., Phys. Rev. A 81, 012715 (2010); D. B. Cassidy et al., Phys. Rev. Lett. 106, 023401 (2011).[0pt] [4] D. B. Cassidy and A. P. Mills Jr, Nature 449, 195 (2007); D. B. Cassidy and A. P. Mills, Jr, Phys. Rev. Lett, 100 013401 (2008); D. B. Cassidy, V. E. Meligne, and A. P. Mills, Jr., Phys. Rev. Lett. 104, 173401 (2010).[0pt] [5] P.M. Platzman and A.P. Mills, Jr., Phys. Rev. B 49, 454 (1994).[0pt] [6] E.P. Liang and C. D. Dermer, Opt. Commun. 65, 419 (1988).
Cassidy, David
Contemporary Aspects of Atomic Physics
ERIC Educational Resources Information Center
The approach generally used in writing undergraduate textbooks on Atomic and Nuclear Physics presents this branch as historical in nature. Describes the concepts of astrophysics, plasma physics and spectroscopy as contemporary and intriguing for modern scientists. (PS)
Knott, R. G. A.
Theoretical atomic collision physics
The current focus of the research is low-energy (collision v<
Lane, N.F.
EDITORIAL: High precision atomic physics High precision atomic physics
NASA Astrophysics Data System (ADS)
Accurate atomic collision and structure data are an essential ingredient for a wide range of research fields as well as for major technological applications. Areas from laboratory physics to quantum processing, from plasma research applications in nuclear fusion to lighting research, as well as astrophysics and cosmology, depend critically on such data. But many data still exhibit inconsistencies and inaccuracies, so that significant efforts are continuing to improve the data quality. Additionally, a substantial body of much-needed data is absent from the published literature and from databases. Appreciable progress is being made, aided by greatly improved, or even entirely new, laboratory equipment and by vastly expanded computer power, which has made possible the development of greatly refined atomic structure codes. Thus in recent years, atomic data have not only become more accurate, but the body of data has also greatly increased, highly ionized species and complex heavy atoms have been addressed, fully relativistic treatments have been developed, and new energy and frequency ranges have been explored. This special issue focuses on many of these new sophisticated theoretical and experimental approaches that have made high precision atomic physics a reality. On the experimental side, several contributions cover the area of highly charged ions, where accurate measurements have become possible mainly due to the availability of electron beam ion traps (EBITs) and the utilization of storage rings. Studies of QED effects in Li-like ions, determinations of atomic lifetimes and precision wavelength measurements of highly charged ions are discussed. Furthermore, two contributions illustrate the extremely high precision of spectroscopic measurements for heavy ions and atoms, and two fundamental investigations address a new search for the electric dipole moment of the electron and measurements of the anapole moment in Fr and Rb. On the theoretical side, the contributions demonstrate that new, expanded and refined atomic structure and electron-impact collision codes are successfully applied to complex atomic systems, such as highly charged ions and heavy atoms, using increasingly full relativistic treatments.
Hibbert, Alan; Johnson, Walter; Wiese, Wolfgang
Advances in atomic, molecular, and optical physics
The following subjects are reviewed: Comparison of positron and electron scattering by gases. Electron capture at relativistic energies. The low-energy, heavy-particle collisions - a close-coupling treatment. Vibronic phenomena in collisions of atomic and molecular species. Associative ionization: experiments, potentials, and dynamics. On the beta decay of 187Re: an interface of atomic and nuclear physics and of cosmochronology. Progress in low
D. Bates; B. Bederson
Supercomputers and atomic physics data
The advent of the supercomputer has dramatically increased the possibilities for generating and using massive amounts of detailed fine structure atomic physics data. Size, speed, and software have made calculations which were impossible just a few years ago into a reality. Further technological advances make future possibilities seem endless. The cornerstone atomic structure codes of R.D. Cowan have been adapted into a single code CATS for use on Los Alamos supercomputers. We provide a brief overview of the problem; and report a sample CATS calculation using configuration interaction to calculate collision and oscillator strengths for over 300,000 transitions in neutral nitrogen. We also discuss future supercomputer needs. 2 refs.
Abdallah, J. Jr.; Clark, R.E.H.
Experiments With Trapped Neutral Atoms.
National Technical Information Service (NTIS)
Major steps were taken to explore superfluidity in Fermi clouds. This created close links with condensed matter and many body physics. During the funding period, major advances were done towards atom interferometry with Bose-Einstein condensates. The goal...
W. Ketterle
Demonstration Experiments in Physics
ERIC Educational Resources Information Center
This book represents a "cookbook" for teachers of physics, a book of recipes for the preparation of demonstration experiments to illustrate the principles that make the subject of physics so fascinating. Illustrations and explanations of each demonstration are done in an easy-to-understand format. Each can be adapted to be used as a demonstration�
Sutton, Richard M.
NSDL National Science Digital Library
Colorado State University's Hands-On Science Outreach Program, Little Shop of Physics, contains several dozen online experiments that can be done at home, in the classroom, or directly on a computer. The Amazing Physics section offers directions on completing the classic imploding pop can experiment and other experiments using common household items. The other two sections, Computer Stuff and Shockwave Stuff, allows users to try interactive activities like the headshrinker experiment. After staring at the animation of moving circles for a minute and then looking at a friend's head, it strangely appears to be shrinking. Each detailed experiment provides clear and straightforward directions as well as an explanation of what is actually happening, making this site an excellent resource for teachers and parents in helping kids understand physics.
Bringing Atoms into First-Year Physics.
ERIC Educational Resources Information Center
Argues that thermal physics should not be treated as a separate topic in introductory physics. Provides an example of a course that emphasizes physical modeling of the phenomenon in terms of the atomic nature of matter. (Author/CCM)
Chabay, Ruth W.; Sherwood, Bruce A.
ERIC Educational Resources Information Center
Describes experiments in ice physics that demonstrate the behavior and properties of ice. Show that ice behaves as an ionic conductor in which charge is transferred by the movement of protons, its electrical conductivity is highly temperature-dependent, and its dielectric properties show dramatic variation in the kilohertz range. (Author/GA)
Martin, P. F.; And Others
Theoretical atomic and molecular physics
In this first year of the grant, emphasis has been placed on theoretical investigations of: differential elastic and charge-transfer scattering and alignment and orientation of the excited electron cloud in ion-atom, atom-atom and ion-molecule collisions, using a molecular-orbital representation; quenching of low-lying Rydberg states of a Na atom in a collision with a ground-state He atom, using a semiclassical representation;
Relativistic atomic physics at the SSC
This report discusses the following proposed work for relativistic atomic physics at the Superconducting Super Collider: Beam diagnostics; atomic physics research; staffing; education; budget information; statement concerning matching funds; description and justification of major items of equipment; statement of current and pending support; and assurance of compliance.
Physics in Action: Seeing Atoms
NSDL National Science Digital Library
This article describes how scanning probe microscopes can be used to see atoms, which are too small to see with optical instruments. These instruments can be used for a wide range of both imaging and control of atoms. The site contains diagrams, pictures, and links to research in this field.
Central, Physics
Classical approach in atomic physics
NASA Astrophysics Data System (ADS)
The application of a classical approach to various quantum problems - the secular perturbation approach to quantization of a hydrogen atom in external fields and a helium atom, the adiabatic switching method for calculation of a semiclassical spectrum of a hydrogen atom in crossed electric and magnetic fields, a spontaneous decay of excited states of a hydrogen atom, Gutzwiller's approach to Stark problem, long-lived excited states of a helium atom discovered with the help of Poincar� section, inelastic transitions in slow and fast electron-atom and ion-atom collisions - is reviewed. Further, a classical representation in quantum theory is discussed. In this representation the quantum states are treated as an ensemble of classical states. This approach opens the way to an accurate description of the initial and final states in classical trajectory Monte Carlo (CTMC) method and a purely classical explanation of tunneling phenomenon. The general aspects of the structure of the semiclassical series such as renormgroup symmetry, criterion of accuracy and so on are reviewed as well.
Solov'ev, E. A.
Einstein's contributions to atomic physics
Many of the epoch-breaking papers that have been published by Einstein are remembered today as treatises dealing with various isolated phenomena rather than as direct consequences of a new unified world view. This paper traces the various ways in which ten papers published by Einstein during the period 1905-1925 influenced the development of the modern atomic paradigm, and illustrates how
Lorenzo J Curtis
Atomic physics using large electrostatic accelerators
This article surveys some areas of atomic physics using large electro-static accelerators. Brief overviews of ion-atom collisions and ion-solid collisions are followed by a classified listing of recent paper. A single line, correlated electron ion recombination, is chosen to show the recent development of techniques to study various aspects of this phenomenon. 21 refs., 11 figs., 1 tab.
Datz, S.
Bringing atoms into first-year physics
NSDL National Science Digital Library
We argue that thermal physics should not be treated as a separate topic in introductory physics. The first-year calculus-based college physics should offer a modern, unified view of physics representative of the contemporary scientific enterprise. It should focus on the consequences of the central fact that matter is composed of atoms, and on the process of modeling physical systems. Such a focus is more interesting and relevant to students than a repetition of a purely classical treatment. We give an example of a course that emphasizes physical modeling of phenomena in terms of the atomic nature of matter. Thermal physics is woven into the entire course and is fully integrated with classical and semiclassical mechanics.
Chabay, Ruth; Sherwood, Bruce
Atomic Physics, Science (Experimental): 5318.42.
ERIC Educational Resources Information Center
Presented is the study of modern and classical concepts of the atom; the structure of the atom as a mass-energy relationship; practical uses of radioactivity; isotopes; and the strange particles. Performance objectives (16) are included as well as a detailed course outline. Experiments, demonstrations, projects and reports to enhance student�
Petit, Ralph E.
Scattering processes in atomic physics, nuclear physics, and cosmology
NASA Astrophysics Data System (ADS)
The universal way to probe a physical system is to scatter a particle or radiation off the system. The results of the scattering are governed by the interaction Hamiltonian of the physical system and scattered probe. An object of the investigation can be a hydrogen atom immersed in a laser field, heavy nucleus exposed to a flux of neutrons, or space-time metric perturbed by the stress-energy tensor of neutrino flux in the early Universe. This universality of scattering process designates the Scattering Matrix, defined as the unitary matrix of the overlapping in and out collision states, as the central tool in theoretical physics. In this Thesis we present our results in atomic physics, nuclear physics, and cosmology. In these branches of theoretical physics the key element that unifies all of them is the scattering matrix. Additionally, within the scope of Thesis we present underlying ideas responsible for the unification of various physical systems. Within atomic physics problems, namely the axial anomaly contribution to parity nonconservation in atoms, and two-photon resonant transition in a hydrogen atom, it was the scattering matrix which led to the Landau-Yang theorem, playing the central role in these problems. In scattering problems of cosmology and quantum optics we developed and implemented mathematical tools that allowed us to get a new point of view on the subject. Finally, in nuclear physics we were able to take advantage of the target complexity in the process of neutron scattering which led to the formulation of a new resonance width distribution for an open quantum system.
Shchedrin, Gavriil
Atomic and molecular physics of controlled thermonuclear fusion
This book attempts to provide a comprehensive introduction to the atomic and molecular physics of controlled thermonuclear fusion, and also a self-contained source from which to start a systematic study of the field. Presents an overview of fusion energy research, general principles of magnetic confinement, and general principles of inertial confinement. Discusses the calculation and measurement of atomic and molecular processes relevant to fusion, and the atomic and molecular physics of controlled thermonuclear research devices. Topics include recent progress in theoretical methods for atomic collisions; current theoretical techniques for electron-atom and electronion scattering; experimental aspects of electron impact ionization and excitation of positive ions; the theory of charge exchange and ionization by heavy particles; experiments on electron capture and ionization by multiply charged ions; Rydberg states; atomic and molecular processes in high temperature, low-density magnetically confined plasmas; atomic processes in high-density plasmas; the plasma boundary region and the role of atomic and molecular processes; neutral particle beam production and injection; spectroscopic plasma diagnostics; and particle diagnostics for magnetic fusion experiments.
Joachain, C.J.; Post, D.E.
Broken Atomic Beam Resonance Experiment
Cesium atoms from a heated oven were passed through a bouncing box, ; where they suffered at least two collisions, between two six-pole deflecting ; magnets. The characteristic Ramsey separated oscillatory field resonance pattern ; was found corresponding to atomic transitions between the F =4, M = 0 and F = 3, ; M = 0 state. (W.D.M.);
Daniel Kleppner; Norman F. Ramsey; Paul Fjelstadt
ERIC Educational Resources Information Center
Describes a novel instructional method for physics involving the use of a computer assisted instruction system equipped with cathode-ray-tube terminals, light pen, and keyboard input. Discusses exercises with regard to content, mediation, scoring and control. Several examples of exercises are given along with results from student evaluation. (LC)
Lindsay, Robert E.
Atomic and Molecular Physics at Storage Rings
NASA Astrophysics Data System (ADS)
In the talk, I presented recent results demonstrating the novel research opportunities in atomic and molecular physics at ion-cooler storage rings. For a spectroscopy of atomic and molecular data, it is the extended observation and interaction time of the stored ions that is exploited. Either one excites the ions inside the storage and detects the delayed decay or one inserts excited atomic, molecular, or cluster ions into the ring for measuring the decay of long lived metastable states, molecular and cluster excitations. Metastable levels in ions decay by weak forbidden radiative transitions and the corresponding atomic lifetimes can be ms instead of ns. A laser probing method has been developed to determine such lifetimes in CRYRING [D. Rostohar et al., Phys. Rev. Lett. 86, 1466 (2001)]. The high spectral resolution of the method has opened possibilities to study ions for iron group elements and rare earths elements, for which no experimental studies had been possible previously.
Schuch, R.
"Atomic, Molecular and Optical Physics Inside"
NASA Astrophysics Data System (ADS)
I was fortunate to enjoy the advice of K. G. Emeleus during my graduate studies and for many years afterwards. He introduced me to the papers of Will Allis and later I was privileged to correspond with him. At this time I had moved from the Queens university environment to work at a large Air Force base. A personal overview is presented on the many roles that atomic, molecular and optical physics, including gaseous electronics, play in programs of the AFRL and subsequently on AF systems and operations. AFRL is not only a laboratory; it is also a defense contracting and evaluation agency. The AF sponsors basic research for several reasons:- to have an educated populace and a highly qualified work force for the nation; to enhance the technology options available to the commerce of the nation; to advance national prestige and to provide the Air Force with the best technical capabilities. The organization of AF science and technology starts with the AFOSR as the single manager of AF basic research, (6.1) funded at approximately 221M per year of which more than 70there are the Exploratory Development programs (6.2 at 695M annually) managed by AFRL where concepts are evaluated and components are developed. These programs involve industry and many universities, especially in cooperation with companies. Some of these programs that succeed transition into advanced development (6.3 at $465M annually) where integration occurs to provide a subsystem or system. While there have been misses, overall there have been many successes with impacts that provide more effective systems as recent experiences have demonstrated. The R process and planning are quite involved with Darwinian competitions for resources which then impact the research initiatives, to which principal investigators are requested to respond. Some example studies, involving primarily electron collisions, lasers, flows and combustion physics, successful and unsuccessful, are discussed.
Garscadden, Alan
Planning a School Physics Experiment.
ERIC Educational Resources Information Center
Presents a model for planning the measurement of physical quantities. Provides two examples of optimizing the conditions of indirect measurement for laboratory experiments which involve measurements of acceleration due to gravity and of viscosity by means of Stokes' formula. (ML)
Blasiak, Wladyslaw
Handbook explaining the fundamentals of nuclear and atomic physics
NASA Technical Reports Server (NTRS)
Indoctrination document presents nuclear, reactor, and atomic physics in an easy, straightforward manner. The entire subject of nuclear physics including atomic structure ionization, isotopes, radioactivity, and reactor dynamics is discussed.
Hanlen, D. F.; Morse, W. J.
Atomic physics with a relativistic H- beam
NASA Astrophysics Data System (ADS)
A study is currently under way at the Fermi National Accelerator Laboratory for a superconducting linear accelerator that will accelerate H- ions to 8?GeV. This Proton Driver beam is intended to be injected, stripped down to protons, into the 120?GeV Main Injector for the mass production of neutrinos aimed at a neutrino detector (MINOS) in a mine shaft in Soudan, Minnesota, USA, for the study of neutrino oscillations. The highly relativistic kinematics of the one- and two-electron atomic systems (H0 and H-) that could be produced by this accelerator present unique research opportunities in atomic physics for the study of fundamental questions. Finally we shall discuss the effects of black-body radiation on high-energy H- beams.
Bryant, H. C.; Herling, G. H.
Theoretical atomic physics code development III TAPS: A display code for atomic physics data
A large amount of theoretical atomic physics data is becoming available through use of the computer codes CATS and ACE developed at Los Alamos National Laboratory. A new code, TAPS, has been written to access this data, perform averages over terms and configurations, and display information in graphical or text form. 7 refs., 13 figs., 1 tab.
Clark, R.E.H.; Abdallah, J. Jr.; Kramer, S.P.
Sustained Spheromak Physics Experiment, SSPX
The Sustained Spheromak Physics Experiment is proposed for experimental studies of spheromak confinement issues in a controlled way: in steady state relative to the confinement timescale and at low collisionality. Experiments in a flux - conserver will provide data on transport in the presence of resistive modes in shear-stabilized systems and establish operating regimes which pave the way for true steady-state experiments with the equilibrium field supplied by external coils. The proposal is based on analysis of past experiments, including the achievement of T{sub e} = 400 eV in a decaying spheromak in CTX. Electrostatic helicity injection from a coaxial ``gun`` into a shaped flux conserver will form and sustain the plasma for several milliseconds. The flux conserver minimizes fluxline intersection with the walls and provides MHD stability. Improvements from previous experiments include modem wall conditioning (especially boronization), a divertor for density and impurity control, and a bias magnetic flux for configurational flexibility. The bias flux will provide innovative experimental opportunities, including testing helicity drive on the large-radius plasma boundary. Diagnostics include Thomson scattering for T{sub e} measurements and ultra-short pulse reflectrometry to measure density and magnetic field profiles and turbulence. We expect to operate at T{sub e} of several hundred eV, allowing improved understanding of energy and current transport due to resistive MHD turbulence during sustained operation. This will provide an exciting advance in spheromak physics and a firm basis for future experiments in the fusion regime.
Hooper, E.B.
Rydberg constant and fundamental atomic physics
A detailed report on the current status of measurements of the Rydberg constant is given. Our recently reported value of R/sub infinity/ = 109 737.315 73(3) cm/sup -1/ has been confirmed by three other laboratories within experimental error. An additional check on the iodine cell, the heart of our wavelength and frequency reference, confirms a negligible pressure shift. The possible role of the Rydberg constant in fundamental atomic physics lies in tests of quantum electrodynamics and in improvement of the realization of the meter. We propose that the hydrogen spectrum be used to realize the meter in the optical domain, as an alternative to the current frequency chains. For the realization to be useful, improvement of the current precision of the Rydberg constant by a factor of 2 or more is required.
Zhao, P.; Lichten, W.; Zhou, Z.; Layer, H.P.; Bergquist, J.C.
Trapping Yb Atoms for an EDM Experiment
NASA Astrophysics Data System (ADS)
We are investigating the possible use of a magneto-optical trap (MOT) and optical dipole trap to search for the CP-violating permanent electric dipole moment (EDM) by nuclear spin resonance in Yb (ytterbium) atoms. Optical cooling and trapping of Yb offers many advantages for an atomic EDM experiment including long spin-relaxation lifetimes and a zero average motional magnetic field v�E. The ultra-high vacuum necessary for the trap suppresses spurious magnetic fields due to leakage currents and will allow us to apply a high electric field. Similar EDM experiments have been proposed for the trapped heavy atoms Cs and Fr. However, the ^171Yb atoms are free from the large cross-sections for cold atom collisions that limit the sensitivity of the Cs and Fr experiments because Yb is diamagnetic with a spin-1/2 nucleus. We will use the ^1S0 arrow ^1P1 (398.9 nm) transition for cooling and trapping. The ^1P1 state has a relatively short lifetime of 5 ns, allowing a large laser cooling force to be applied to the atoms. The transition is almost a closed 2-state system, minimizing the need for an extra cleanup laser. We have frequency doubled a Ti:Sapphire laser with an LBO crystal to 398.9 nm and have observed fluorescence from this transition in a Yb beam. We have completed the initial studies for building the MOT and will discuss further progress and possible future experiments. Further information can be found at ?rb"http://www.phys.washington.edu/r~einam/" A>.
Maruyama, Reina; Fortson, Norval; Romalis, Michael
Physics with the ALICE experiment
NASA Astrophysics Data System (ADS)
ALICE experiment at LHC collects data in pp collisions at 1497-1 = 0.9, 2.76, and 7 TeV and in PbPb collisions at 2.76 TeV. Highlights of the detector performance and an overview of experimental results measured with ALICE in pp and AA collisions are presented in this paper. Physics with protonproton collisions is focused on hadron spectroscopy at low and moderate p t . Measurements with lead-lead collisions are shown in comparison with those in pp collisions, and the properties of hot quark matter are discussed.
Kharlov, Yu. V.
Atomic physics and non-equilibrium plasmas
Three lectures comprise the report. The lecture, Atomic Structure, is primarily theoretical and covers four topics: (1) Non-relativistic one-electron atom, (2) Relativistic one-electron atom, (3) Non-relativistic many-electron atom, and (4) Relativistic many-electron atom. The lecture, Radiative and Collisional Transitions, considers the problem of transitions between atomic states caused by interactions with radiation or other particles. The lecture, Ionization Balance: Spectral Line Shapes, discusses collisional and radiative transitions when ionization and recombination processes are included. 24 figs., 11 tabs.
Weisheit, J.C.
Recent Results on Lorentz Violation in Atomic Experiments
NASA Astrophysics Data System (ADS)
Tests of Lorentz symmetry provide a potential means of detecting new physics originating at the Planck scale. The effects of hypothetical violations of Lorentz symmetry in experiments performed at presently accessible energies are described by the Standard-Model Extension (SME). In this talk, I will discuss recently proposed tests of Lorentz symmetry based on an investigation of gravitational couplings in the matter sector of the SME. Atom interferometers, torsion pendula, and falling antimatter are among the systems that can attain new sensitivities.
Tasson, Jay; Kostelecky, Alan
Atomic frequency standard relativistic Doppler shift experiment
NASA Technical Reports Server (NTRS)
An experiment has been performed to measure possible space anisotropy as it would effect the frequency of a cesium atomic beam standard clock in a laboratory on earth due to motion relative to external coordinate frames. The cesium frequency was measured as a function of orientation with respect to an atomic hydrogen maser standard. Over a period of 34 days 101 measurements were made. The results are consistent with a conclusion that no general orientation dependance attributable to spacial anisotropy was observed. It is shown that both the airplane clock results, and the null results for the atomic beam clock, are consistent with Einstein general or special relativity, or with the Lorentz transformations alone.
Peters, H. E.; Reinhardt, V. S.
Materials International Space Station Experiment-6 (MISSE-6) Atomic Oxygen Fluence Monitor Experiment
NASA Technical Reports Server (NTRS)
An atomic oxygen fluence monitor was flown as part of the Materials International Space Station Experiment-6 (MISSE-6). The monitor was designed to measure the accumulation of atomic oxygen fluence with time as it impinged upon the ram surface of the MISSE 6B Passive Experiment Container (PEC). This was an active experiment for which data was to be stored on a battery-powered data logger for post-flight retrieval and analysis. The atomic oxygen fluence measurement was accomplished by allowing atomic oxygen to erode two opposing wedges of pyrolytic graphite that partially covered a photodiode. As the wedges of pyrolytic graphite erode, the area of the photodiode that is illuminated by the Sun increases. The short circuit current, which is proportional to the area of illumination, was to be measured and recorded as a function of time. The short circuit current from a different photodiode, which was oriented in the same direction and had an unobstructed view of the Sun, was also to be recorded as a reference current. The ratio of the two separate recorded currents should bear a linear relationship with the accumulated atomic oxygen fluence and be independent of the intensity of solar illumination. Ground hyperthermal atomic oxygen exposure facilities were used to evaluate the linearity of the ratio of short circuit current to the atomic oxygen fluence. In flight, the current measurement circuitry failed to operate properly, thus the overall atomic oxygen mission fluence could only be estimated based on the physical erosion of the pyrolytic graphite wedges. The atomic oxygen fluence was calculated based on the knowledge of the space atomic oxygen erosion yield of pyrolytic graphite measured from samples on the MISSE 2. The atomic oxygen fluence monitor, the expected result and comparison of mission atomic oxygen fluence based on the erosion of the pyrolytic graphite and Kapton H atomic oxygen fluence witness samples are presented in this paper.
Banks, Bruce A.; Miller, Sharon K.; Waters, Deborah L.
Quantum dynamics in ultracold atomic physics
NASA Astrophysics Data System (ADS)
We review recent developments in the theory of quantum dynamics in ultracold atomic physics, including exact techniques and methods based on phase-space mappings that are applicable when the complexity becomes exponentially large. Phase-space representations include the truncated Wigner, positive- P and general Gaussian operator representations which can treat both bosons and fermions. These phase-space methods include both traditional approaches using a phase-space of classical dimension, and more recent methods that use a non-classical phase-space of increased dimensionality. Examples used include quantum Einstein-Podolsky-Rosen (EPR) entanglement of a four-mode BEC, time-reversal tests of dephasing in single-mode traps, BEC quantum collisions with up to 106 modes and 105 interacting particles, quantum interferometry in a multi-mode trap with nonlinear absorption, and the theory of quantum entropy in phase-space. We also treat the approach of variational optimization of the sampling error, giving an elementary example of a nonlinear oscillator.
He, Qiong-Yi; Reid, Margaret D.; Opanchuk, Bogdan; Polkinghorne, Rodney; Rosales-Z�rate, Laura E. C.; Drummond, Peter D.
The Role of Experiment in Physics Education
This presentation draws on the ways in which physics is practiced, and presents a variety of ways to use experiments in a physics classroom similar to the ways that experiments are used in physics research. Published in The Physics Teacher, Vol. 40 September 2002, PP. 351-355.
Eugenia Etkina
On the utility and ubiquity of atomic collision physics
This paper is divided into three parts. In the introduction, we discuss the history and makeup of ICPEAC. In the second part, we discuss the extent of applicability of atomic collision physics. In the third part, we chose one subject (dielectronic excitation) to show the interrelationship of various sub-branches of atomic collision physics. 28 refs., 14 figs.
Datz, S.
Atomic physics with ions stored in the round
NASA Astrophysics Data System (ADS)
The talk contained examples of recent atomic physics experiments with stored and cooled ion beams from different ion storage-ring facilities. Here, we first introduce the principles of storage rings and electron cooling. A whole class of experiments exploits the cold electron beams available in the electron coolers and electron targets of storage rings. The recombination experiments have applications in fusion and astrophysical plasmas. Dielectronic resonances at meV to eV energies are measured with a resolution and absolute accuracy to much below a meV. The measurements of these resonances provide a serious challenge to theories for describing correlation, relativistic, quantum electrodynamical effects, and isotope shifts in highly ionized ions. Experiments with internal targets in storage rings use the high luminosity of cooled MeV ions for collisions. First measurements demonstrate the resolution with a He RIMS apparatus (He gas-jet Target for Recoil Ion Momentum Spectroscopy) in Thomas-like electron-transfer processes by protons. An outlook into the future with the new Facility for Anti-proton and Ion Research (FAIR) and the Stored Particle Atomic Research Collaboration (SPARC) is given.
Schuch, R.; B�hm, S.
Divertor bias experiments. General Atomics Project 3466
Electrical biasing of the divertor target plates has recently been implemented on several tokamaks. The results of these experiments to date will be reviewed in this paper. The bias electrode configuration is unique in each experiment. The effects of biasing on the scrape-off layer (SOL) plasma also differ. By comparing results between machines, and using theoretical models, an understanding of the basic physics of biasing begins to emerge. Divertor biasing has been demonstrated to have a strong influence on the particle and energy transport within the SOL. The ability to externally control the SOL plasma with biasing has promising applications to future tokamak reactors.
Staebler, G.M.
Atomic Structure Calculations from the Los Alamos Atomic Physics Codes
The well known Hartree-Fock method of R.D. Cowan, developed at Los Alamos National Laboratory, is used for the atomic structure calculations. Electron impact excitation cross sections are calculated using either the distorted wave approximation (DWA) or the first order many body theory (FOMBT). Electron impact ionization cross sections can be calculated using the scaled hydrogenic method developed by Sampson and co-workers, the binary encounter method or the distorted wave method. Photoionization cross sections and, where appropriate, autoionizations are also calculated. Original manuals for the atomic structure code, the collisional excitation code, and the ionization code, are available from this website. Using the specialized interface, you will be able to define the ionization stage of an element and pick the initial and final configurations. You will be led through a series of web pages ending with a display of results in the form of cross sections, collision strengths or rates coefficients. Results are available in tabular and graphic form.
Cowan, R. D.
The Interactive Plasma Physics Education Experience
NSDL National Science Digital Library
As part of Princeton University's Plasma Physics Laboratory, the Interactive Plasma Physics Education Experience Web site contains interactive plasma physics topics, ranging from electricity and magnetism to energy and fusion. Although some of the activities have difficulty running on old browsers and Macintosh computers, the interactive lessons give students a fun and engaging way to explore physics topics.
Application of Atomic-Absorption Spectroscopy in Physics Research.
National Technical Information Service (NTIS)
Some physical applications of atomic absorption spectroscopy for determining the damping parameter alpha, oscillator strength values f, and temperature T are critically discussed. On the basis of detailed theoretical analysis, the potentialities and limit...
B. V. Lvov
ERIC Educational Resources Information Center
NASA GSFC Science Symposium on Atomic and Molecular Physics
NASA Technical Reports Server (NTRS)
This document is the proceedings of a conference on atomic and molecular physics in honor of the retirements of Dr. Aaron Temkin and Dr. Richard Drachman. The conference contained discussions on electron, positron, atomic, and positronium physics, as well as a discussion on muon catalyzed fusion. This proceedings document also contains photographs taken at the symposium, as well as speeches and a short biography made in tribute to the retirees.
Bhatia, Anand K. (Editor)
MISSE Scattered Atomic Oxygen Characterization Experiment
NASA Technical Reports Server (NTRS)
An experiment designed to measure the atomic oxygen (AO) erosion profile of scattered AO was exposed to Low Earth Orbital (LEO) AO for almost four years as part of the Materials International Space Station Experiment 1 and 2 (MISSE 1 and 2). The experiment was flown in MISSE Passive Experiment Carrier 2 (PEC 2), Tray 1, attached to the exterior of the International Space Station (ISS) Quest Airlock. The experiment consisted of an aperture disk lid of Kapton H (DuPont) polyimide coated on the space exposed surface with a thin AO durable silicon dioxide film. The aperture lid had a small hole in its center to allow AO to enter into a chamber and impact a base disk of aluminum. The AO that scattered from the aluminum base could react with the under side of the aperture lid which was coated sporadically with microscopic sodium chloride particles. Scattered AO erosion can occur to materials within a spacecraft that are protected from direct AO attack but because of apertures in the spacecraft the AO can attack the interior materials after scattering. The erosion of the underside of the Kapton lid was sufficient to be able to use profilometry to measure the height of the buttes that remained after washing off the salt particles. The erosion pattern indicated that peak flux of scattered AO occurred at and angle of approximately 45 from the incoming normal incidence on the aluminum base unlike the erosion pattern predicted for scattering based on Monte Carlo computational predictions for AO scattering from Kapton H polyimide. The effective erosion yield for the scattered AO was found to be a factor of 0.214 of that for direct impingement on Kapton H polyimide.
Banks, Bruce A.; deGroh, Kim K.; Miller, Sharon K.
Theoretical Atomic Physics code development IV: LINES, A code for computing atomic line spectra
A new computer program, LINES, has been developed for simulating atomic line emission and absorption spectra using the accurate fine structure energy levels and transition strengths calculated by the (CATS) Cowan Atomic Structure code. Population distributions for the ion stages are obtained in LINES by using the Local Thermodynamic Equilibrium (LTE) model. LINES is also useful for displaying the pertinent atomic data generated by CATS. This report describes the use of LINES. Both CATS and LINES are part of the Theoretical Atomic PhysicS (TAPS) code development effort at Los Alamos. 11 refs., 9 figs., 1 tab.
Abdallah, J. Jr.; Clark, R.E.H.
LASSP: The Laboratory of Atomic and Solid State Physics
NSDL National Science Digital Library
The Laboratory of Atomic and Solid State Physics (LASSP) at Cornell University is a center for research in condensed matter physics. Scientists can read about the work of the thirty faculty members in topics such as theoretical condensed matter physics, low temperature physics, experimental liquid physics, and experimental soft-condensed matter and biological physics. With a number of images and animations at the website, students can learn about diffraction patterns of an icosahedral quasicrystal, Coarsening, and Spiral Defect Turbulence. Physicists can find employment opportunities at LASSP as well as information on upcoming seminars, conferences, and meetings.
University of Oregon Physics Applets: Atomic Emission
NSDL National Science Digital Library
This applet presents the user with an energy level diagram of an atom. The values of the levels (in eV) can be set by parameter tags. Relative transition probabilities can also be set by parameter tags. An active electron can be moved to any level by using the pointing device and then the electron will cascade down to the ground level according to the relative transition probabilities that have been set up. Each time the electron moves from a higher to lower energy level a photon will be emitted. The wavelength of the photon is indicated and some attempt is to color code the outgoing photon by the emitted wavelength.
Bothun, Gregory
Status of the Los Alamos free atomic tritium beta-decay experiment
An experiment to study the beta-decay of tritium using a gaseous source of free (unbound) atomic tritium is currently underway in the Physics Division at Los Alamos. The use of free atomic tritium along with careful design of the measurement scheme should allow a definitive determination for an electron antineutrino mass approx. 10 eV.
Wilkerson, J.F.; Bowles, T.J.; Browne, J.C.; Burritt, T.H.; Cohen, J.S.; Helffrich, J.A.; Knapp, D.A.; Maley, M.P.; Martin, R.L.; Robertson, R.G.H.
Positron spectroscopy in atomic and solid state physics
Basic research problems in Atomic Physics with positrons (total cross sections, Ramsauer minima, positronium formation, selective ionization) and some benchmark measurements in Solid State Physics using positron annihilation (He-created nano-voids in Si, Oxygen precipitates in Si, low ? materials) are discussed.
G. P. Karwasz; R. S. Brusa; A. Zecca
Classical Physics Experiments in the Amusement Park
ERIC Educational Resources Information Center
An amusement park is a large physics laboratory, full of rotating and accelerated coordinate systems. The forces are experienced throughout the body and can be studied with simple equipment or with electronics depending on age and experience. In this paper, we propose adaptations of classical physics experiments for use on traditional rides.�
Bagge, Sara; Pendrill, Ann-Marie
Simulating educational physical experiments in augmented reality
We present an augmented reality application for mechanics education. It utilizes a recent physics engine developed for the PC gaming market to simulate physical experiments in the domain of mechanics in real time. Students are enabled to actively build own experiments and study them in a three-dimensional virtual world. A variety of tools are provided to analyze forces, mass, paths
Hannes Kaufmann; Bernd Meyery
Division of Atomic Physics. Lund Institute of Technology. Progress Report 1993-1994.
National Technical Information Service (NTIS)
The Division of Atomic Physics is responsible for basic physics teaching in all engineering disciplines and for specialized teaching in Optics, Atomic Physics, Spectroscopy, Laser Physics, and Non-Linear Optics. Research activities are mainly carried out ...
C. G. Wahlstroem
Experiment and the foundations of quantum physics
Instead of having to rely on gedanken (thought) experiments, it is possible to base this discussion of the foundations of quantum physics on actually performed experiments because of the enormous experimental progress in recent years. For reasons of space, the author discusses mainly experiments related to the Einstein-Podolsky-Rosen paradox and Bell's theorem, that is, to quantum entanglement. Not only have
Anton Zeilinger
Customized Laboratory Experience in Physical Chemistry
ERIC Educational Resources Information Center
A new physical chemistry laboratory experience has been designed for upper-level undergraduate chemistry majors. Students customize the first 10 weeks of their laboratory experience by choosing their own set of experiments (from a manual of choices) and setting their own laboratory schedule. There are several topics presented in the accompanying�
Castle, Karen J.; Rink, Stephanie M.
Accelerator physics experiments at Aladdin
The Aladdin accelerator is a 1 GeV synchrotron light source located at the University of Wisconsin. The results of experimental studies of the Aladdin accelerator are described. The primary purpose of the experiments reported was to investigate reported anomalies in the behavior of the linear lattice, particularly in the vertical plane. A second goal was to estimate the ring broadband impedance. Experimental observations and interpretation of the linear properties of the Aladdin ring are described, including the beta function and dispersion measurements. Two experiments are described to measure the ring impedance, the first a measurement of the parasitic mode loss, and the second a measurement of the beam transfer function. Measurements of the longitudinal and transverse emittance at 100 and 200 MeV are described and compared with predictions. 10 refs., 24 figs., 2 tabs. (LEW)
Chattopadhyay, S.; Cornacchia, M.; Jackson, A.; Zisman, M.S.
Atoms in flight and the remarkable connections between atomic and hadronic physics
NASA Astrophysics Data System (ADS)
Atomic physics and hadron physics are both based on Yang Mills gauge theory; in fact, quantum electrodynamics can be regarded as the zero-color limit of quantum chromodynamics. I review a number of areas where the techniques of atomic physics provide important insight into the theory of hadrons in QCD. For example, the Dirac-Coulomb equation, which predicts the spectroscopy and structure of hydrogenic atoms, has an analog in hadron physics in the form of light-front relativistic equations of motion which give a remarkable first approximation to the spectroscopy, dynamics, and structure of light hadrons. The renormalization scale for the running coupling, which is unambiguously set in QED, leads to a method for setting the renormalization scale in QCD. The production of atoms in flight provides a method for computing the formation of hadrons at the amplitude level. Conversely, many techniques which have been developed for hadron physics, such as scaling laws, evolution equations, and light-front quantization have equal utility for atomic physics, especially in the relativistic domain. I also present a new perspective for understanding the contributions to the cosmological constant from QED and QCD.
Brodsky, Stanley J.
Atoms in flight and the remarkable connections between atomic and hadronic physics
NASA Astrophysics Data System (ADS)
Atomic physics and hadron physics are both based on Yang Mills gauge theory; in fact, quantum electrodynamics can be regarded as the zero-color limit of quantum chromodynamics. I review a number of areas where the techniques of atomic physics provide important insight into the theory of hadrons in QCD. For example, the Dirac-Coulomb equation, which predicts the spectroscopy and structure of hydrogenic atoms, has an analog in hadron physics in the form of light-front relativistic equations of motion which give a remarkable first approximation to the spectroscopy, dynamics, and structure of light hadrons. The renormalization scale for the running coupling, which is unambiguously set in QED, leads to a method for setting the renormalization scale in QCD. The production of atoms in flight provides a method for computing the formation of hadrons at the amplitude level. Conversely, many techniques which have been developed for hadron physics, such as scaling laws, evolution equations, and light-front quantization have equal utility for atomic physics, especially in the relativistic domain. I also present a new perspective for understanding the contributions to the cosmological constant from QED and QCD.
Brodsky, Stanley J.
Atoms in Flight: The Remarkable Connections between Atomic and Hadronic Physics
Atomic physics and hadron physics are both based on Yang Mills gauge theory; in fact, quantum electrodynamics can be regarded as the zero-color limit of quantum chromodynamics. I review a number of areas where the techniques of atomic physics provide important insight into the theory of hadrons in QCD. For example, the Dirac-Coulomb equation, which predicts the spectroscopy and structure of hydrogenic atoms, has an analog in hadron physics in the form of light-front relativistic equations of motion which give a remarkable first approximation to the spectroscopy, dynamics, and structure of light hadrons. The renormalization scale for the running coupling, which is unambiguously set in QED, leads to a method for setting the renormalization scale in QCD. The production of atoms in flight provides a method for computing the formation of hadrons at the amplitude level. Conversely, many techniques which have been developed for hadron physics, such as scaling laws, evolution equations, and light-front quantization have equal utility for atomic physics, especially in the relativistic domain. I also present a new perspective for understanding the contributions to the cosmological constant from QED and QCD.
Brodsky, Stanley J.; /SLAC
Current experiments in elementary-particle physics
NASA Astrophysics Data System (ADS)
Microfiche are included which contain summaries of 479 experiments in elementary particle physics. Experiments are included at the following laboratories: Brookhaven (ENL); CERN; DESY; Fermilab. (FNAL); Institute for Nuclear Studies (INS); KEK; LAMPF; Serpukhov (SERP); SIN; SLAC; and TRIUMP. Also, summries of proton decay experiments are included. A list of experiments and titles is included; and a beam-target-momentum index and a spokesperson index are given. Properties of beams at the facilities are tabulated.
Wohl, C. G.; Armstrong, F. E.; Rittenberg, A.
Current experiments in elementary particle physics. Revised
This report contains summaries of 584 current and recent experiments in elementary particle physics. Experiments that finished taking data before 1986 are excluded. Included are experiments at Brookhaven, CERN, CESR, DESY, Fermilab, Tokyo Institute of Nuclear Studies, Moscow Institute of Theoretical and Experimental Physics, KEK, LAMPF, Novosibirsk, Paul Scherrer Institut (PSI), Saclay, Serpukhov, SLAC, SSCL, and TRIUMF, and also several underground and underwater experiments. Instructions are given for remote searching of the computer database (maintained under the SLAC/SPIRES system) that contains the summaries.
Galic, H. [Stanford Univ., CA (United States). Stanford Linear Accelerator Center; Wohl, C.G.; Armstrong, B. [Lawrence Berkeley Lab., CA (United States); Dodder, D.C. [Los Alamos National Lab., NM (United States); Klyukhin, V.I.; Ryabov, Yu.G. [Inst. for High Energy Physics, Serpukhov (Russian Federation); Illarionova, N.S. [Inst. of Theoretical and Experimental Physics, Moscow (Russian Federation); Lehar, F. [CEN Saclay, Gif-sur-Yvette (France); Oyanagi, Y. [Univ. of Tokyo (Japan). Faculty of Sciences; Olin, A. [TRIUMF, Vancouver, BC (Canada); Frosch, R. [Paul Scherrer Inst., Villigen (Switzerland)
Practical Physics: Basic Experiments with Ripple Tanks
NSDL National Science Digital Library
This resource contains a set of eight introductory experiments on wave reflections, appropriate for use in high school and middle school. Students are introduced to ripple tanks and gain confidence in using them by doing some simple experiments with pulses. SEE RELATED ITEMS on this page for a Teachers' Guide on using ripple tanks, and for ripple tank experiments for the more advanced classroom. This item is part of a much larger collection of physics/astronomy experiments, sponsored by the UK's Institute of Physics and funded by the Nuffield Curriculum Centre.
Centre, Nuffield C.
The Physics of Bird Flight: An Experiment
NASA Astrophysics Data System (ADS)
This article describes an experiment that measures the forces acting on a flying bird during takeoff. The experiment uses a minimum of equipment and only an elementary knowledge of kinematics and Newton's second law. The experiment involves first digitally videotaping a bird during takeoff, analyzing the video to determine the bird's position as a function of time and its flapping rate, calculating the velocity of the bird's wings, and finally, inserting those results into Newton's second law of physics. The experiment has been designed for a high school physics class. This article is a follow-up on our recently published theoretical article on the origin of bird flight.1
Mihail, Michael D.; George, Thomas F.; Feldman, Bernard J.
Photonic doppler velocimetry in shock physics experiments
Doppler velocimetry techniques are frequently used in Shock-Physics experiments to measure material velocities (as a function of time). With such diagnostics, there is no physical contact between the probe and the target, which presents the advantage of not intruding the observed phenomenon. They also provide very good precision on the velocities. Those techniques are either based on homodyne methods (such
P. Mercier; J. Benier; A. Azzolina; J. M. Lagrange; D. Partouche
Experiences and Perceptions of Physical Education
ERIC Educational Resources Information Center
This research has studied how children and young people, who are deemed by their school to have social, emotional and behavioural difficulties (SEBD), experience the National Curriculum of Physical Education (PE) in England. Research has previously highlighted the physical, social, affective and cognitive benefits of participation in PE.�
Medcalf, Richard; Marshall, Joe; Hardman, Ken; Visser, John
Atomic Physics with High-Brightness Synchrotron X-Ray Sources.
National Technical Information Service (NTIS)
A description of atomic physics experiments that we intend to carry out at the National Synchrotron Light Source is given. Emphasis is given to work that investigates the properties of multiply charged ions. The use of a synchrotron storage ring for highl...
K. W. Jones B. M. Johnson M. Meron
High Temperature Facility for Atomic Physics Studies. Final Report.
National Technical Information Service (NTIS)
The results of a program designed to develop a laser heated plasma sample for atomic physics studies in the 30 to 100 eV range of electron temperature and the 3 x 10 exp 17 to 10 exp 18 cm exp -3 range in electron density are presented. The approach used ...
APIPIS: The Atomic Physics Ion-Photon Interaction System.
National Technical Information Service (NTIS)
A proposed new facility for the study of highly charged heavy ions is described. The basic elements of APIPIS, the Atomic Physics Ion-Photon Interaction System, are: (1) a source of multiply-charged ions; (2) a linear accelerator; (3) a synchrotron storag...
B. M. Johnson K. W. Jones M. Meron V. O. Kostroun
HISTRAP proposal: heavy ion storage ring for atomic physics
HISTRAP, Heavy Ion Storage Ring for Atomic Physics, is a proposed 46.8-m-circumference synchrotron-cooling-storage ring optimized to accelerate, decelerate, and store beams of highly charged very-heavy ions at energies appropriate for advanced atomic physics research. The ring is designed to allow studies of electron-ion, photon-ion, ion-atom, and ion-ion interactions. An electron cooling system will provide ion beams with small angular divergence and energy spread for precision spectroscopic studies and also is necessary to allow the deceleration of heavy ions to low energies. HISTRAP will have a maximum bending power of 2.0 Tm and will be injected with ions from either the existing Holifield Heavy Ion Research Facility 25-MV tandem accelerator or from a dedicated ECR source and 250 keV/nucleon RFQ linac.
Olsen, D.K.; Alton, G.D.; Datz, S.; Dittner, P.F.; Dowling, D.T.; Haynes, D.L.; Hudson, E.D.; Johnson, J.W.; Lee, I.Y.; Lord, R.S.
Low-Cost Accelerometers for Physics Experiments
ERIC Educational Resources Information Center
The implementation of a modern game-console controller as a data acquisition interface for physics experiments is discussed. The investigated controller is equipped with three perpendicular accelerometers and a built-in infrared camera to evaluate its own relative position. A pendulum experiment is realized as a demonstration of the proposed�
Vannoni, Maurizio; Straulino, Samuele
Photoelectroconversion by Semiconductors: A Physical Chemistry Experiment.
ERIC Educational Resources Information Center
Presents an experiment designed to give students some experience with photochemistry, electrochemistry, and basic theories about semiconductors. Uses a liquid-junction solar cell and illustrates some fundamental physical and chemical principles related to light and electricity interconversion as well as the properties of semiconductors. (JRH)
Fan, Qinbai; And Others
This is the fourth edition of our compilation of current high energy physics experiments. It is a collaborative effort of the Berkeley Particle Data Group, the SLAC library, and nine participating laboratories: Argonne (ANL), Brookhaven (BNL), CERN, DESY, Fermilab (FNAL), the Institute for Nuclear Study, Tokyo (INS), KEK, Serpukhov (SERP), and SLAC. The compilation includes summaries of all high energy physics experiments at the above laboratories that (1) were approved (and not subsequently withdrawn) before about April 1981, and (2) had not completed taking of data by 1 January 1977. We emphasize that only approved experiments are included.
Wohl, C.G.; Kelly, R.L.; Armstrong, F.E.; Horne, C.P.; Hutchinson, M.S.; Rittenberg, A.; Trippe, T.G.; Yost, G.P.; Addis, L.; Ward, C.E.W.; Baggett, N.; Goldschmidt-Clermong, Y.; Joos, P.; Gelfand, N.; Oyanagi, Y.; Grudtsin, S.N.; Ryabov, Yu.G.
Current Experiments in Particle Physics (September 1996)
This report contains summaries of current and recent experiments in Particle Physics. Included are experiments at BEPC (Beijing), BNL, CEBAF, CERN, CESR, DESY, FNAL, Frascati, ITEP (Moscow), JINR (Dubna), KEK, LAMPF, Novosibirsk, PNPI (St. Petersburg), PSI, Saclay, Serpukhov, SLAC, and TRIUMF, and also several proton decay and solar neutrino experiments. Excluded are experiments that finished taking data before 1991. Instructions are given for the World Wide Web (WWW) searching of the computer database (maintained under the SLAC-SPIRES system) that contains the summaries. This report contains full summaries of 180 approved current and recent experiments in elementary particle physics. The focus of the report is on selected experiments which directly contribute to our better understanding of elementary particles and their properties such as masses, widths or lifetimes, and branching fractions.
Galic, H.; Lehar, F.; Klyukhin, V.I.; Ryabov, Yu.G.; Bilak, S.V.; Illarionova, N.S.; Khachaturov, B.A.; Strokovsky, E.A.; Hoffman, C.M.; Kettle, P.-R.; Olin, A.; Armstrong, F.E.
Summary of informal meeting on ''facilities for atomic physics research with highly ionized atoms''
An informal meeting to discuss ''Facilities for Atomic Physics Research with Highly Ionized Atoms'' was held during the APS DEAP meeting at the University of Connecticut on May 30, 1984. The meeting was motivated by the realization that the status of facilities for studies of highly ionized atoms is unsettled and that it might be desirable to take action to ensure adequate resources for research over the whole range of charge states and energies of interest. It was assumed that the science to be done with these beams has been amply documented in the literature.
Cocke, C.L.; Jones, K.W.
Atomic physics with highly charged ions. Progress report
The study of inelastic collision phenomena with highly charged projectile ions and the interpretation of spectral features resulting from these collisions remain as the major focal points in the atomic physics research at the J.R. Macdonald Laboratory, Kansas State University, Manhattan, Kansas. The title of the research project, ``Atomic Physics with Highly Charged Ions,`` speaks to these points. The experimental work in the past few years has divided into collisions at high velocity using the primary beams from the tandem and LINAC accelerators and collisions at low velocity using the CRYEBIS facility. Theoretical calculations have been performed to accurately describe inelastic scattering processes of the one-electron and many-electron type, and to accurately predict atomic transition energies and intensities for x rays and Auger electrons. Brief research summaries are given for the following: (1) electron production in ion-atom collisions; (2) role of electron-electron interactions in two-electron processes; (3) multi-electron processes; (4) collisions with excited, aligned, Rydberg targets; (5) ion-ion collisions; (6) ion-molecule collisions; (7) ion-atom collision theory; and (8) ion-surface interactions.
Richard, P.
Introducing many-body physics using atomic spectroscopy
NASA Astrophysics Data System (ADS)
Atoms constitute relatively simple many-body systems, making them suitable objects for developing an understanding of basic aspects of many-body physics. Photoabsorption spectroscopy is a prominent method to study the electronic structure of atoms and the inherent many-body interactions. In this article, the impact of many-body effects on well-known spectroscopic features, such as Rydberg series, Fano resonances, Cooper minima, and giant resonances, is studied and related many-body phenomena in other fields are outlined. To calculate photoabsorption cross sections, the time-dependent configuration interaction singles (TDCIS) model is employed. The conceptual clearness of TDCIS in combination with the compactness of atomic systems allows for a pedagogical introduction to many-body phenomena.
Krebs, Dietrich; Pabst, Stefan; Santra, Robin
Plasma Gate: Free Software for Atomic and Plasma Physics
NSDL National Science Digital Library
Maintained by the Plasma Laboratory of Weizmann Institute of Science, the Free Software for Atomic and Plasma Physics Web site contains over thirty links to various programs. Examples of available software include Weizmann Institutes: 369j-symbol calculator and Russia's Institute of Spectroscopy's spectral bibliography database. Although several of the links currently seem to be dead, the site does give those working in this field access to several sites with useful software programs.
The Physics of the Imploding Can Experiment
ERIC Educational Resources Information Center
One of the popular demonstrations of atmospheric pressure in introductory physics courses is the "crushing can" or "imploding can" experiment. In this demonstration, which has also been extensively discussed on the Internet, a small amount of water is placed in a soda can and heated until it boils and water vapor almost entirely fills the can. The�
Mohazzabi, Pirooz
Theoretical atomic physics code development I: CATS: Cowan Atomic Structure Code
An adaptation of R.D. Cowan's Atomic Structure program, CATS, has been developed as part of the Theoretical Atomic Physics (TAPS) code development effort at Los Alamos. CATS has been designed to be easy to run and to produce data files that can interface with other programs easily. The CATS produced data files currently include wave functions, energy levels, oscillator strengths, plane-wave-Born electron-ion collision strengths, photoionization cross sections, and a variety of other quantities. This paper describes the use of CATS. 10 refs.
Abdallah, J. Jr.; Clark, R.E.H.; Cowan, R.D.
Atomic physics at the Argonne PII ECR (electron cyclotron resonance) Ion Source
An atomic physics beam line has been set up at the Argonne PII ECR Ion Source. The source is on a 350-kV high-voltage platform which is a unique feature of particular interest in work on atomic collisions. We describe our planned experimental program which includes: measurement of state-selective electron-capture cross sections, studies of doubly-excited states, precision spectroscopy of few-electron ions, tests of quantum electrodynamics, and studies of polarization transfer using optically pumped polarized alkali targets. The first experiments will be measurements of cross sections for electron capture into specific nl subshells in ion-atom collisions. Our method is to observe the characteristic radiation emitted after capture using a VUV spectrometer. Initial data from these experiments are presented. 12 refs., 4 figs.
Dunford, R.W.; Berry, H.G.; Billquist, P.J.; Pardo, R.C.; Zabransky, B.J.; Bakke, E.; Groeneveld, K.O.; Hass, M.; Raphaelian, M.L.A.
Informal proposal for an Atomic Physics Facility at the National Synchrotron Light Source
An Atomic Physics Facility (APF) for experiments that will use radiation from a superconducting wiggler on the NSLS X-13 port is described. The scientific justification for the APF is given and the elements of the facility are discussed. It is shown that it will be possible to conduct a uniquely varied set of experiments that can probe most aspects of atomic physics. A major component of the proposal is a heavy-ion storage ring capable of containing ions with energies of about 10 MeV/nucleon. The ring can be filled with heavy ions produced at the BNL MP Tandem Laboratory or from independent ion-source systems. A preliminary cost estimate for the facility is presented.
Jones, K.W.; Johnson, B.M.; Meron, M.
Atomic physics with high-brightness synchrotron x-ray sources
A description of atomic physics experiments that we intend to carry out at the National Synchrotron Light Source is given. Emphasis is given to work that investigates the properties of multiply charged ions. The use of a synchrotron storage ring for highly charged heavy ions is proposed as a way to produce high current beams which will make possible experiments to study the photoexcitation and ionization of multiply charged ions for the first time. Experiments along the same lines which are feasible at the proposed Advanced Light Source are considered briefly. 7 refs., 2 figs.
Jones, K.W.; Johnson, B.M.; Meron, M.
Electron-atom collisions: From Franck-Hertz experiment to atom traps
The key features of the cross sections for electron-impact excitation out of the ground levels of the rare-gas atoms are summarized and application of these cross section data is shown. This is followed by discussions of recent experiments on determination of electron-impact cross sections for excitation out of the metastable levels of He and Ar. The metastiable atom targets are produced by two different methods, i.e., hollow-cathode discharges and charge-exchange collisions of rare-gas ions with Cs atoms. The former method is simple but is limited to low electron energies because of the very small metastable concentration, whereas the latter method yields a fast target beam with predominantly metastable atoms allowing measurements up to the keV range. The measured cross sections show features very different from those of excitation out of the ground levels. Another new development in electron-atom collision is the use of atom traps for measuring ionization cross sections. The experiment is conducted by passing an electron beam pulse through magneto-optically trapped Rb atoms while the trap is momentarily turned off. Turning the trap back on immediately after the electron beam pulse recaptures the unionized atoms allowing only the ions to escape. The ionization cross section is determined by measuring the electron beam current density at the trapped atom region and the fractional loss of trapped atoms due to the electron beam. This method avoids measurements of the absolute number of the target atoms and the overlap between the atomic and electron beams and therefore eliminates the major sources of uncertainty associated with the crossed-beam method for measuring ionization cross section.
Lin, C.C. [Univ. of Wisconsin, Madison, WI (United States)
Atomic oxygen effects on LDEF experiment AO171
NASA Astrophysics Data System (ADS)
The Solar Array Materials Passive Long Duration Exposure Facility (LDEF) Experiment (SAMPLE), AO171, contained in total approximately 100 materials and materials processes with a 300 specimen complement. With the exception of experiment solar cell and solar cell modules, all test specimens were weighed before flight, thus allowing an accurate determination of mass loss as a result of space exposure. Since almost all of the test specimens were thermal vacuum baked before flight, the mass loss sustained can be attributed principally to atomic oxygen attack. The atomic oxygen effects observed and measured in five classes of materials is documented. The atomic oxygen reactivity values generated for these materials are compared to those values derived for the same materials from exposures on short term shuttle flights. An assessment of the utility of predicting long term atomic oxygen effects from short term exposures is given. This experiment was located on Row 8 position A which allowed all experiment materials to be exposed to an atomic oxygen fluence of 6.93 x 10(exp 21) atoms/cm(sup 2) as a result of being positioned 38 degrees off the RAM direction.
Whitaker, Ann F.; Kamenetzky, Rachel R.; Finckenor, Miria M.; Norwood, Joseph K.
HISTRAP proposal: heavy ion storage ring for atomic physics
HISTRAP is a proposed synchrotron-cooling-storage ring optimized to accelerate, decelerate, and store beams of highly charged very-heavy ions at energies appropriate for advanced atomic physics research. The ring is designed to allow studies of electron-ion, photon-ion, ion-atom, and ion-ion interactions. An electron cooling system will provide ion beams with small angular divergence and energy spread for precision spectroscopic studies and also is necessary to allow the deceleration of heavy ions to low energies. HISTRAP will be injected with ions from either the existing Holifield Heavy Ion Research Facility 25-MV tandem accelerator or from a dedicated ECR source and 250 keV/nucleon RFQ linac. The ring will have a maximum bending power of 2.0 T.m and have a circumference of 46.8 m.
Olsen, D.K.; Alton, G.D.; Datz, S.; Dittner, P.F.; Dowling, D.T.; Haynes, D.L.; Hudson, E.D.; Johnson, J.W.; Lee, I.Y.; Lord, R.S.
Adapting Transformative Experience Surveys to Undergraduate Physics
NSDL National Science Digital Library
Transformative experience (TE) is a theoretical construct intended to capture the extent to which science concepts learned in the classroom shape students' everyday meaning-making and engagement with science outside the classroom. One tool available to assess the depth and prevalence of TE is with surveys. We have been adapting existing surveys for use in various undergraduate physics courses at two different institutions, including algebra-based introductory physics courses and physical science courses for pre-service elementary teachers. We describe our efforts to modify existing surveys for use across different courses and content areas and describe our initial findings concerning the depth and prevalence of TE. From survey data, large differences can be detected in both the depth of students' overall engagement and the degree to which that engagement falls off when students are not in the classroom or working on required assignments.
Frank, Brian W.; Atkins, Leslie J.
Using the Wiimote in Introductory Physics Experiments
NASA Astrophysics Data System (ADS)
The Wii is a very popular gaming console. An important component of its appeal is the ease of use of its remote controller, popularly known as a Wiimote. This simple-looking but powerful device has a three-axis accelerometer and communicates with the console via Bluetooth protocol. We present two experiments that demonstrate the feasibility of using the Wiimote in introductory physics experiments. The linear dependence of centripetal acceleration on the radial distance at constant angular velocity is verified and compared with data obtained using photogate timers. A second application to simple harmonic oscillators tests the capabilities of the Wiimote to measure variable accelerations.
Ochoa, Romulo; Rooney, Frank G.; Somers, William J.
Atomic and Nuclear Physics with Stored Particles in Ion Traps
NASA Astrophysics Data System (ADS)
Trapping and cooling techniques play an increasingly important role in many areas of science. This review concentrates on recent applications of ion traps installed at accelerator facilities to atomic and nuclear physics such as mass spectrometry of radioactive isotopes, weak interaction studies, symmetry tests, determination of fundamental constants, laser spectroscopy, and spectroscopy of highly-charged ions. In addition, ion traps are proven to be extremely efficient devices for (radioactive) ion beam manipulation as, for example, retardation, accumulation, cooling, beam cleaning, charge-breeding, and bunching.
Kluge, H.-J.; Blaum, K.; Herfurth, F.; Quint, W.
APIPIS: the Atomic Physics Ion-Photon Interaction System
A proposed new facility for the study of highly charged heavy ions is described. The basic elements of APIPIS, the Atomic Physics Ion-Photon Interaction System, are: (1) a source of multiply-charged ions; (2) a linear accelerator; (3) a synchrotron storage ring; and (4) a source of high brightness x rays. The placement of a heavy ion storage ring at the x-ray ring of the National Synchrotron Light Source will provide unique opportunities for the study of photo-excitation of heavy ions.
Johnson, B.M.; Jones, K.W.; Meron, M.; Kostroun, V.O.
Microwave ionization of highly excited hydrogen atoms: Experiment and theory
This article elaborates on a talk delivered by the first author at the First International Conference on the Physics of Phase Space (University of Maryland, 20�23 May 1986). It reviews briefly our still limited, but rapidly growing understanding of a dynamical process, the ionization of highly-excited hydrogen atoms by a microwave electric field. Classical dynamics explains surprisingly well many recent
P. Koch; K. van Leeuwen; O. Rath; D. Richards; R. V. Jensen
MOLAT: Atomic and Molecular Physics Databases of the Paris Observatory
NASA Astrophysics Data System (ADS)
MOLAT (http://molat.obspm.fr/) is a joint project of several departments of the Paris Observatory supported by its Scientific Council. Its purpose is to make available original atomic and molecular data and compilations produced independently or in the course of collaborations by members of the Observatory. The data are of interest for the interpretation of observations made by spaceborne or ground based instruments and of laboratory experiments. The experimental data include mainly VUV spectroscopic data obtained by the Meudon group using either the 10m high resolution VUV spectrograph of the Meudon Observatory or the LURE-Orsay synchrotron facility. The theoretical data include calculations from different groups of the Observatory concerning atomic or molecular structures, radiative transition probabilities, collisional excitation cross-sections and line broadening parameters. The bibliographic compilations are maintained by members of the Observatory. The database also provides a selection of links to other pertinent atomic or molecular databases thus serving as a gateway between atomic and molecular physicists and astrophysicists. The data formats have been kept as provided by the authors. An effort is underway to give a unified presentation.
Bruston, M.; Cornille, M.; Dubau, J.; Eidelsberg, M.; Lesage, A.; Launay, F.; Rostas, F.; Spielfiedel, A.; Tchang-Brillet, W.-�. L.
FROM THE HISTORY OF PHYSICS: Moscow State University physics alumni and the Soviet Atomic Project
NASA Astrophysics Data System (ADS)
In this paper, two closely related themes are addressed: (1) the role that M V Lomonosov Moscow State University (MSU) played in training specialists in physics for the Soviet Atomic Project, and (2) what its alumni contributed to the development of thermonuclear weapons. In its earlier stages, the Soviet Atomic Project was in acute need of qualified personnel, without whom building nuclear and thermonuclear weapons would be an impossible task, and MSU became a key higher educational institution grappled with the training problem. The first part of the paper discusses the efforts of the leading Soviet scientists and leaders of FMD (First Main Directorate) to organize the training of specialists in nuclear physics at the MSU Physics Department and, on the other hand, to create a new Physics and Technology Department at the university. As a result, a number of Soviet Government's resolutions were prepared and issued, part of which are presented in the paper and give an idea of the large-scale challenges this sphere of education was facing at the time. Information is presented for the first time on the early MSU Physics Department graduates in the structure of matter, being employed in the FMD organizations and enterprises from 1948 to 1951. The second part discusses the contribution to the development of thermonuclear weapons by the teams of scientists led by Academicians I E Tamm, A N Tikhonov, and I M Frank, and including MSU physics alumni. The paper will be useful to anyone interested in the history of Russian physics.
Kiselev, Gennadii V.
Microprocessors in physics experiments at SLAC
The increasing size and complexity of high energy physics experiments is changing the way data are collected. To implement a trigger or event filter requires complex logic which may have to be modified as the experiment proceeds. Simply to monitor a detector, large amounts of data must be processed on line. The use of microprocessors or other programmable devices can help to achieve these ends flexibly and economically. At SLAC, a number of microprocessor-based systems have been built and are in use in experimental setups, and others are now being developed. This talk is a review of existing systems and their use in experiments, and of developments in progress and future plans.
Rochester, L.S.
Analysis of the physical atomic forces between noble gas atoms, alkali ions and halogen ions
NASA Technical Reports Server (NTRS)
The physical forces between atoms and molecules are important in a number of processes of practical importance, including line broadening in radiative processes, gas and crystal properties, adhesion, and thin films. The components of the physical forces between noble gas atoms, alkali ions, and halogen ions are analyzed and a data base for the dispersion forces is developed from the literature based on evaluations with the harmonic oscillator dispersion model for higher order coefficients. The Zener model of the repulsive core is used in the context of the recent asymptotic wave functions of Handler and Smith; and an effective ionization potential within the Handler and Smith wave functions is defined to analyze the two body potential data of Waldman and Gordon, the alkali-halide molecular data, and the noble gas crystal and salt crystal data. A satisfactory global fit to this molecular and crystal data is then reproduced by the model to within several percent. Surface potentials are evaluated for noble gas atoms on noble gas and salt crystal surfaces with surface tension neglected. Within this context, the noble gas surface potentials on noble gas and salt crystals are considered to be accurate to within several percent.
Wilson, J. W.; Heinbockel, J. H.; Outlaw, R. A.
Containerless experiments in fluid physics in microgravity
NASA Technical Reports Server (NTRS)
The physical phenomena associated with the behavior of liquid samples freely suspended in low gravity must be thoroughly understood prior to undertaking detailed scientific studies of the materials under scrutiny. The characteristics of molten specimens under the action of containerless positioning stresses must be identified and separated from the specific phenomena relating to the absence of an overwhelming gravitational field. The strategy designed to optimize the scientific return of reliable experimental data from infrequent microgravity investigations should include the gradual and logical phasing of more sophisticated studies building on the accumulated results from previous flight experiments. Lower temperature fluid physics experiments using model materials can provide a great deal of information that can be useful in analyzing the behavior of high temperature melts. The phasing of the experimental capabilities should, therefore, also include a gradual build-up of more intricate and specialized diagnostic instrumentation and environmental control and monitoring capabilities. Basic physical investigations should also be distinguished from specific materials technology issues. The latter investigations require very specific high temperature (and high vacuum) devices that must be thoroughly mastered on the ground prior to implementing them in space.
Trinh, E. H.
Tokamak physics experiment: Diagnostic windows study
We detail the study of diagnostic windows and window thermal stress remediation in the long-pulse, high-power Tokamak Physics Experiment (TPX) operation. The operating environment of the TPX diagnostic windows is reviewed, thermal loads on the windows estimated, and cooling requirements for the windows considered. Applicable window-cooling technology from other fields is reviewed and its application to the TPX windows considered. Methods for TPX window thermal conditioning are recommended, with some discussion of potential implementation problems provided. Recommendations for further research and development work to ensure performance of windows in the TPX system are presented.
Merrigan, M.; Wurden, G.A.
Yankee atomic experience with coastdown. Report YAEC-1270
This report summarizes Yankee Atomic's operating experience with 19 coastdowns in three different nuclear power plants. The observed effects of coastdown on plant capacity factor, efficiency, maneuverability, and fuel integrity are demonstrated. Calculations of resource requirements and fuel cycle economics for equilibrium cycles show typical savings of 3 to 5% for cycles using coastdown compared to those which produce the same energy without coastdown.
Quan, B.L.; Malone, J.P.; Pilat, E.E.
Operational experiences at the Gulf General Atomic TRIGA reactors facility
Gulf General Atomic has extensive experience in operating on a continuing basis several models of the family of TRIGA reactors; namely, a Mark I (12 years), a Mark F (10 years), a below ground Mark III (4 years), and an annular core critical facility (6 months). These reactors have been used for a variety of purposes including (a) the development
Physical mechanisms for atomization of a jet spray
Because combustion in direct injection engines is strongly influenced by the details of the fuel spray in thes engines, the authors have begun a broad research effort of jet breakup experiments and modelling of these high pressure sprays. The main objective of this effort is to better understand fuel injection from the study of the spray-jet breakup process and the associated fuel-oxidant mixing. The focus of this paper is the development of specific models for atomization of the spray-jet. These models are then compared to each other and to preliminary data from the spray-jet breakup experiments. Initial results indicate that KIVA with this proposed spray model shows good agreement with low pressure data (69 MPa) but underestimates spray penetration for higher pressures (104 MPa).
Bower, G.; Chang, S.K.; Corradini, M.L.; El-Beshbeeshy, M.; Martin, J.K.; Krueger, J.
Characterization of the Source Physics Experiment Site
NASA Astrophysics Data System (ADS)
Designed to improve long-range treaty monitoring capabilities, the Source Physics Experiments, conducted at the Nevada National Security Site, also provide an opportunity to advance near-field monitoring and field-based investigations of suspected underground test locations. In particular, features associated with underground testing can be evaluated using Source Physics Experiment activities as analogs, linking on-site inspections with remote sensing technologies. Following a calibration shot (SPE 1), SPE 2 (10/2011) and SPE 3 (07/2012) were performed in the same emplacement hole with 1.0 ton of explosives at 150 ft depth. Because one of the goals of the Source Physics Experiments is to determine damage effects on seismic wave propagation and improve modeling capabilities, a key component in the predictive component and ultimate validation of the models is a full understanding of the intervening geology between the source and instrumented bore holes. Ground-based LIDAR and fracture mapping, mechanical properties determined via laboratory testing of rock core, discontinuity analysis and optical microscopy of the core rocks were performed prior to and following each experiment. In addition, gravity and magnetic data were collected between SPE 2 and 3. The source region of the explosions was also characterized using cross-borehole seismic tomography and vertical seismic profiling utilizing two sets of two boreholes within 40 meters of ground zero. The two sets of boreholes are co-linear with the explosives hole in two directions. Results of the LIDAR collects from both SPE 2 and 3 indicate a permanent ground displacement of up to several centimeters aligning along the projected surface traces of two faults observed in the core and fractures mapped at the surface. Laboratory testing and optical work show a difference in the characteristics of the rocks below and above 40 feet and within the fault zones.The estimated near-surface densities from the gravity survey show substantial changes in apparent near-surface density and may help explain independently-observed near-surface velocity changes. Work by Los Alamos National Laboratory was sponsored by the National Nuclear Security AdministrationAward No. DE-AC52-06NA25946/NST10-NCNS-PD00. Work by National Security Technologies, LLC, was performed under Contract No. DE AC52 06NA25946 with the U.S. Department of Energy. Sandia National Laboratories, is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.
Sussman, A. J.; Schultz-Fellenz, E. S.; Broome, S. T.; Townsend, M.; Abbott, R. E.; Snelson, C. M.; Cogbill, A. H.; Conklin, G.; Mitra, G.; Sabbeth, L.
Atomic Physics in the Quest for Fusion Energy and ITER
The urgent quest for new energy sources has led developed countries, representing over half of the world population, to collaborate on demonstrating the scientific and technological feasibility of magnetic fusion through the construction and operation of ITER. Data on high-Z ions will be important in this quest. Tungsten plasma facing components have the necessary low erosion rates and low tritium retention but the high radiative efficiency of tungsten ions leads to stringent restrictions on the concentration of tungsten ions in the burning plasma. The influx of tungsten to the burning plasma will need to be diagnosed, understood and stringently controlled. Expanded knowledge of the atomic physics of neutral and ionized tungsten will be important to monitor impurity influxes and derive tungsten concentrations. Also, inert gases such as argon and xenon will be used to dissipate the heat flux flowing to the divertor. This article will summarize the spectroscopic diagnostics planned for ITER and outline areas where additional data is needed.
Charles H. Skinner
The laboratory experience in introductory physics courses
NASA Astrophysics Data System (ADS)
The last two decades or so have witnessed intense efforts to improve the teaching and learning of physics. Scholarly studies have provided the grounding for many projects which reform the structure of introductory courses. A number of these innovations, however, are resource intensive, or depend on the ability to introduce changes in areas which are beyond the control of the faculty (e.g., scheduling), thus inhibiting their implementation. An alternative strategy that overcomes these obstacles is to modify the nature of the laboratory experience (a component that practically nobody disputes is an essential part of the introductory course), to provide hands-on learning opportunities that differ from the traditional ``follow-this-recipe-to-verify-this-law'' approach. I have chosen to implement a variety of activities that support the overall objectives of the course: developing conceptual understanding and transferable skills, and providing practice in the ways scientists actually do science. Given the audience in this two-semester, algebra-based course, mostly biology majors and pre-professionals (health-related careers, such as medicine, physical therapy, and veterinary), these goals were identified as the most important and lasting contribution that a physics course can make to the students intellectual development. I offer here examples of the types of hands on activities that I have implemented, organized for the sake of this presentation in four rather loose categories, depending on which subset of the course objectives the activities mostly address: self-designed lab activities, discussion of demo-type activities, building concepts from simple to complex, and out-of-lab physical phenomena.
di Stefano, Maria C.
Probing physical properties at the nanoscale using atomic force microscopy
NASA Astrophysics Data System (ADS)
Techniques that measure physical properties at the nanoscale with high sensitivity are significantly limited considering the number of new nanomaterials being developed. The development of atomic force microscopy (AFM) has lead to significant advancements in the ability to characterize physical properties of materials in all areas of science: chemistry, physics, engineering, and biology have made great scientific strides do to the versatility of the AFM. AFM is used for quantification of many physical properties such as morphology, electrical, mechanical, magnetic, electrochemical, binding interactions, and protein folding. This work examines the electrical and mechanical properties of materials applicable to the field of nano-electronics. As electronic devices are miniaturized the demand for materials with unique electrical properties, which can be developed and exploited, has increased. For example, discussed in this work, a derivative of tetrathiafulvalene, which exhibits a unique loss of conductivity upon compression of the self-assembled monolayer could be developed into a molecular switch. This work also compares tunable organic (tetraphenylethylene tetracarboxylic acid and bis(pyridine)s assemblies) and metal-organic (Silver-stilbizole coordination compounds) crystals which show high electrical conductivity. The electrical properties of these materials vary depending on their composition allowing for the development of compositionally tunable functional materials. Additional work was done to investigate the effects of molecular environment on redox active 11-ferroceneyl-1 undecanethiol (Fc) molecules. The redox process of mixed monolayers of Fc and decanethiol was measured using conductive probe atomic force microscopy and force spectroscopy. As the concentration of Fc increased large, variations in the force were observed. Using these variations the number of oxidized molecules in the monolayer was determined. AFM is additionally capable of investigating interactions at the nanoscale, such as ligand-receptor interactions. This work examines the interactions between the enzyme dihydrofolate reductase (DHFR), a widely investigated enzyme targeted for cancer and antimicrobial pharmaceutical, and methotrexate (MTX), a strong competitive inhibitor of DHFR. The DHFR was immobilized on a gold substrate, bound through a single surface cysteine, and maintained catalytic activity. AFM probe was functionalized with MTX and the interaction strength was measured using AFM. This work highlights the versatility of AFM, specifically force spectroscopy for the quantification of electrical, mechanical, and ligand-receptor interactions at the nanoscale.
Ditzler, Lindsay Rachel
LDEF experiment A0034: Atomic oxygen stimulated outgassing
NASA Technical Reports Server (NTRS)
The passive Long Duration Exposure Facility (LDEF) Experiment A0034, 'Atomic Oxygen Stimulated Outgassing', consisted of two identical one-sixth tray modules, exposing selected thermal control coatings to atomic oxygen and the combined space environment on the leading edge, and for reference, to the relative 'wake' environment of the trailing edge. Optical mirrors were included adjacent to the thermal coatings for deposition of the outgassing products. Ultraviolet grade windows and metal covers were provided for additional assessment of the effects of various environmental factors. Preliminary results indicate that orbital atomic oxygen is both a degrading and optically restorative factor in the thermo-optical properties of selected thermal coatings. There is evidence of more severe optical degradation on collector mirrors adjacent to coatings that were exposed to RAM-impinging atomic oxygen. This evidence of atomic oxygen stimulated outgassing is discussed in relation to alternative factors that could affect degradation. The general effects of the space environment on the experiment hardware as well as the specimens are discussed.
Linton, Roger C.; Kamenetzky, Rachel R.; Reynolds, John M.; Burris, Charles L.
Role of Experiments in Physics Instruction - A Process Approach
This paper describes an approach to classroom experiments that serves roles closer to that in the practice of physics. We propose that in the history of physics most ``classical'' experiments fall into one of three groups: observational experiments, testing theoretical model experiments, or application experiments.
E. Etkina; A. van Heuvelen; D. T. Brookes; D. Mills
A latest developed all permanent magnet ECRIS for atomic physics research at IMP
Electron cyclotron resonance (ECR) ion sources have been used for atomic physics research for a long time. With the development of atomic physics research in the Institute of Modern Physics (IMP), additional high performance experimental facilities are required. A 300 kV high voltage (HV) platform has been under construction since 2003, and an all permanent magnet ECR ion source is
L. T. Sun; H. W. Zhao; Z. M. Zhang; H. Wang; B. H. Ma; J. Y. Li; X. Z. Zhang; Y. C. Feng; X. H. Guo; X. X. Li; X. W. Ma; M. T. Song; W. L. Zhan
A capstone research experience for physics majors
NASA Astrophysics Data System (ADS)
Dickinson College is a small liberal arts college with a thriving physics program. For years, one of the key features of our program has been a year-long senior research project that was required for each student. Unfortunately, as our number of majors increased, it became more and more difficult to supervise such a large number of senior research projects. To deal with this growing challenge, we developed a capstone research experience that involves a larger number of students working together on an independent group project. In this talk I will give a broad overview of our new senior research model and provide a few examples of projects that have been carried out over the past few years. I will also briefly describe the positive and negative aspects of this model from the perspective of faculty and students.
Jackson, David
Controlled Space Physics Experiments using Laboratory Magnetospheres
NASA Astrophysics Data System (ADS)
Modern society's reliance on space-based platforms for a variety of economic and geopolitical purposes makes understanding the physics of the magnetosphere and "space weather'' one of the most important applications of plasma science. During the past decade, results from the CTX and LDX laboratory magnetospheres and from the RT-1 device at University of Tokyo, we have developed techniques to explore space physics using controlled experiments in laboratory magnetospheres. This presentation briefly reviews observations from the laboratory magnetospheres at Columbia University and MIT, including adiabatic drift-resonant transport, low-frequency MHD turbulence, and the formation of high-beta plasmas with profiles similar to Earth's inner magnetosphere. First principle validation of ``whole plasma'' space weather models have been completed in relevant magnetic geometry, including the spectrum and dynamics of turbulence successfully modeled with nonlinear bounce-averaged gyrokinetic simulations. Plans to explore Alfv�nic dynamics and whistler wave trapping are discussed through the achievement of higher-density plasmas using radio-frequency heating. Photographs of the laboratory magnetospheres located at MIT (top) and Columbia University (bottom).
Mauel, M. E.; Kesner, J.; Garnier, D.
Atomic detection in microwave cavity experiments: A dynamical model
NASA Astrophysics Data System (ADS)
We construct a model for the atomic detection in the context of cavity quantum electrodynamics (QED) used to study coherence properties of superpositions of states of an electromagnetic mode. Analytic expressions for the atomic ionization are obtained, considering the imperfections of the measurement process due to the probabilistic nature of the interactions between the ionization field and the atoms. We provide for a dynamical content for the available expressions for the counting rates considering limited efficiency of detectors. Moreover, we include false countings. The influence of these imperfections on the information about the state of the cavity mode is obtained. In order to test the adequacy of our approach, we investigate a recent experiment reported by Ma�tre [X. Ma�tre , Phys. Rev. Lett. 79, 769 (1997)] and we obtain excellent agreement with the experimental results.
Rossi, R., Jr.; Nemes, M. C.; Peixoto de Faria, J. G.
COSY data acquisition system for physical experiments
This paper reports that for nuclear physics experiments at the internal and external beam of the Julich Cooler Synchrotron COSY, a three-level data processing and acquisition system is developed. Signals from various detector arrangements are digitized and preprocessed by CAMAC, FASTBUS and VME modules. A multiprocessor system based on VME bus is used for event-building, data recording and buffered data transfer to the host computer. All crates are connected by parallel VICbus. For this, an intelligent CAMAC crate controller with VICbus is under development. Microcomputer-based VME modules are equipped with CPU's of the 680XO family, working under OS-9 real-time operating system. The data acquisition system is mainly based on commercially available modules. For experiment control and data analysis, workstations as part of a local cluster are provided. Proprietary standards developed at CERN, together with OSF open standards will be implemented. TCP/IP protocols for VMEbus masters and host computer serve for initialization and command transfer.
Erven, W.; Holzer, J.; Kopp, H.; Loevenich, H.W.; Meiling, W.; Zwoll, K. (Forschungszentrum Juelich, Zentrallabor fuer Elektronik (DE)); Karnadi, M.; Nellen, R.; Watzlawik, K.H. (Forschungszentrum Juelich, Inst. fuer Kemphysik (DE))
Proof-of-concept experiments for quantum physics in space
Quantum physics experiments in space using entangled photons and satellites are within reach of current technology. We propose a series of fundamental quantum physics experiments that make advantageous use of the space infrastructure with specific emphasis on the satellite-based distribution of entangled photon pairs. The experiments are feasible already today and will eventually lead to a Bell-experiment over thousands of
Rainer Kaltenbaek; Markus Aspelmeyer; Thomas Jennewein; Caslav Brukner; Anton Zeilinger; Martin Pfennigbauer; Walter R. Leeb
Skylab experiments. Volume 1: Physical science, solar astronomy
NASA Technical Reports Server (NTRS)
The basic subject of this volume is the solar astronomy program conducted on Skylab. In addition to descriptions of the individual experiments and the principles involved in their performance, a brief description is included of the sun and the energy characteristics associated with each zone. Wherever possible, related classroom activities have been identified and discussed in some detail. It will be apparent that the relationships rest not only in the field of solar astronomy, but also in the following subjects: (1) physics - optics, electromagnetic spectrum, atomic structure, etc.; (2) chemistry - emission spectra, kinetic theory, X-ray absorption, etc.; (3) biology - radiation and dependence on the sun; (4) electronics - cathode ray tubes, detectors, photomultipliers, etc.; (5) photography; (6) astronomy; and (7) industrial arts.
LEO Atomic Oxygen Measurements: Experiment Design and Preliminary Results
NASA Astrophysics Data System (ADS)
Recently two University of Southampton flight experiments intended to measure the LEO atomic oxygen (AO) flux or fluence have been launched. The first forms part of the Southampton Transient Oxygen and Radiation Monitor (STORM) instrument package that is included as part of the European Materials Exposure and Degradation Experiment on EuTEF (MEDET) module now residing on the external pay load facility of the Columbus laboratory on the International Space Station (ISS). The atomic oxygen detectors on STORM comprise screen-printed thick films of a carbon-polymer resistive ink and also thin sputtered films of zinc oxide. The second is a relatively simple experiment package comprising thick-film carbon-polymer sensors similar to those on STORM; this experiment is currently being flown on the Canadian CanX-2 nano-satellite mission. The design and mode of operation of both types of AO sensor will be described and the current status of both of these experiments will be reviewed.
Roberts, G. T.; Chambers, A. R.; White, C. B.
Atomic physics with highly-charged heavy ions at the GSI future facility: The scientific program of the SPARC collaboration
NASA Astrophysics Data System (ADS)
The proposed new international accelerator Facility for Antiproton and Ion Research (FAIR) will open up exciting and far-reaching perspectives for atomic physics research in the realm of highly-charged heavy ions: it will provide the highest intensities of relativistic beams of both stable and unstable heavy nuclei. In combination with the strongest possible electromagnetic fields produced by the nuclear charge of the heaviest nuclei, this will allow to extend atomic spectroscopy up to the virtual limits of atomic matter. Based on the experience and results already achieved at the experimental storage ring (ESR), a substantial progress in atomic physics research has to be expected in this domain, due to a tremendous improvement of intensity, energy and production yield of both stable and unstable nuclei.
Gumberidze, A.; Bosch, F.; Br�uning-Demian, A.; Hagmann, S.; K�hl, Th.; Liesen, D.; Schuch, R.; St�hlker, Th.; SPARC Collaboration
FROM THE HISTORY OF PHYSICS: The Schr�dinger atom
Aspects of an electrodynamical interpretation of the wave function suggested by Schr�dinger are described. According to this conception, electron charge is continuously distributed throughout the interior of the atomic system. A proof is given that classical electrodynamics holds within an atom. The Schr�dinger atom is shown to be the only model in which electrons do not lose their energy through
A. D. Vlasov
Tokamak Physics Experiment poloidal field design
The Tokamak Physics Experiment (TPX) will have a poloidal field system capable of full inductive operation poloidal for approximately a 20-s flattop and, with superconducting toroidal and poloidal field coils and non-inductive current drive, it will be capable of true steady-state operation. The poloidal field design is based on the ideal MHD equilibrium model as implemented in the TEQ code developed at LLNL. The PF coils are arranged in an up-down symmetric configuration, external to the TF coils. The TPX diverted plasma will have an aspect ratio of 4.5 and is highly shaped with a nominal elongation of 2 and triangularity of approximately 0.8 as measured at the separatrix. The tokamak design is based on a high-current (q{sub {psi}}=3) plasma scenario and a low current scenario. Each scenario has an operational flexibility requirement which is defined as a region of plasma pressure and inductivity ({beta}{sub N} {minus} l{sub i}) space, where the plasma shape is constrained to keep the divertor configuration operational. Single-null plasma configurations are feasible, even with the same divertor hardware, by operating the PF coils asymmetrically. Recently applied optimization techniques have improved the capability of the PF system without additional cost.
Bulmer, R.H.
MISSE 6 Stressed Polymers Experiment Atomic Oxygen Erosion Data
NASA Technical Reports Server (NTRS)
Polymers and other oxidizable materials used on the exterior of spacecraft in the low Earth orbit (LEO) space environment can be eroded away by reaction with atomic oxygen (AO). For spacecraft design, it is important to know the LEO AO erosion yield, Ey (volume loss per incident oxygen atom), of materials susceptible to AO erosion. The Stressed Polymers Experiment was developed and flown as part of the Materials International Space Station Experiment 6 (MISSE 6) to compare the AO erosion yields of stressed and non-stressed polymers to determine if erosion is dependent upon stress while in LEO. The experiment contained 36 thin film polymer samples that were exposed to ram AO for 1.45 years. This paper provides an overview of the Stressed Polymers Experiment with details on the polymers flown, the characterization techniques used, the AO fluence, and the erosion yield results. The MISSE 6 data are compared to data for similar samples flown on previous MISSE missions to determine fluence or solar radiation effects on erosion yield.
deGroh, Kim K.; Banks, Bruce A.; Mitchell, Gianna G.; Yi, Grace T.; Guo, Aobo; Ashmeade, Claire C.; Roberts, Lily M.; McCarthy, Catherine E.; Sechkar, Edward A.
Theoretical atomic and molecular physics: Progress report, July 1, 1988 through June 30, 1989
The theoretical atomic and molecular physics program at Rice University emphasizes fundamental questions regarding the structure and collision dynamics of various atomic and molecular systems with some attention given to atomic processes at surfaces. Our activities have been centered on continuing the projects initiated last year as well as beginning some new studies. These include: differential elastic and charge-transfer scattering
A learning pathway in high-school level quantum atomic physics
In this paper, one student's learning process in a course on quantum atomic physics in grade 13 of a German gymnasium (secondary school) is described. The course lasted 16 weeks for a total of approximately 80 lessons. The aim of the present study is to elaborate the student's cognitive system for atomic physics as a hypothetical pragmatic model to describe,
Juergen Petri; Hans Niedderer
Friendship, physicality, and physical education: an exploration of the social and embodied dynamics of girls� physical education experiences
Physical education represents a dynamic social space where students experience and interpret physicality in a context that accentuates peer relationships and privileges particular forms of embodiment. This article focuses on girls� understandings of physicality with respect to the organisation of physical education and more informal social networks. Research exploring the connections between the body, capital, physical activity, and femininity and
Laura Hills
Fisher-like atomic divergences: Mathematical grounds and physical applications
NASA Astrophysics Data System (ADS)
Two different local divergence measures, the Fisher (FD) and the Jensen-Fisher (JFD) ones, are compared in this work by applying them to atomic one-particle densities in position and momentum spaces. They are defined in terms of the absolute and the relative Fisher information functionals. The analysis here afforded includes not only neutral atoms, but also singly-charged cations. The results are interpreted and justified according to (i) shell-filling patterns, (ii) short- and long-range behaviors of the atomic densities, and (iii) the value of the atomic ionization potential. The strengths of the FD measure, as compared to the JFD one, are emphasized.
Mart�n, A. L.; Angulo, J. C.; Antol�n, J.
Physics Experiments with Nintendo Wii Controllers
ERIC Educational Resources Information Center
This article provides a detailed description of the use of Nintendo Wii game controllers in physics demonstrations. The main features of the controller relevant to physics are outlined and the procedure for communicating with a PC is described. A piece of software written by the author is applied to gathering data from a controller suspended from�
Wheeler, Martyn D.
Efimov physics in bosonic atom-trimer scattering
Bosonic atom-trimer scattering is studied in the unitary limit using momentum-space equations for four-particle transition operators. The impact of the Efimov effect on the atom-trimer scattering observables is explored, and a number of universal relations is established. Positions and widths of tetramer resonances are determined. The trimer relaxation rate constant is calculated.
Deltuva, A. [Centro de Fisica Nuclear da Universidade de Lisboa, P-1649-003 Lisboa (Portugal)
Quantum Dots: An Experiment for Physical or Materials Chemistry
ERIC Educational Resources Information Center
An experiment is conducted for obtaining quantum dots for physical or materials chemistry. This experiment serves to both reinforce the basic concept of quantum confinement and providing a useful bridge between the molecular and solid-state world.
Winkler, L. D.; Arceo, J. F.; Hughes, W. C.; DeGraff, B. A.; Augustine, B. H.
The physics of SU(4) alkaline-earth-atom-based Kondo lattice model at the Toulouse point
NASA Astrophysics Data System (ADS)
The study of ultracold alkaline-earth atoms has gained significant attention due largely to recent efforts to employ ultracold alkaline-earth atoms as a unique platform to explore quantum computing and many-body physics. For alkaline-earth atoms, there is an almost perfect decoupling of the nuclear spin from the electronic angular momentum in both the ground and the metastable states. This along with the existence of relatively high nuclear spin degrees of freedom makes the cold alkaline-earth atoms an excellent candidate that one can employ to study Kondo effects with higher SU(N) spin degrees of freedom. In this work, we focus on a mixture of two-component fermionic alkaline-earth atoms loaded in external optical lattice potentials and treat it as an cold atom implementation of SU(4) Kondo lattice model. We apply bosonization and canonical transformation to obtain an exactly solvable point (the so-called Toulouse point). We study the physics of the system at the Toulouse point by calculating various correlation functions in the parameter regimes that are experimentally accessible to cold atom experiments. This work is supported by the US National Science Foundation and the US Army Research Office.
Duki, Solomon F.; Ling, Hong
Physics experiments with Nintendo Wii controllers
NASA Astrophysics Data System (ADS)
This article provides a detailed description of the use of Nintendo Wii game controllers in physics demonstrations. The main features of the controller relevant to physics are outlined and the procedure for communicating with a PC is described. A piece of software written by the author is applied to gathering data from a controller suspended from a spring undergoing simple harmonic motion, a pair of controllers mounted on colliding gliders on a linear air track, and a person jumping from a balance board.
Wheeler, Martyn D.
Fowler's Physics Applets: Michelson-Morley Experiment
NSDL National Science Digital Library
This page simulates the 1887 Michelson-Morley Experiment, one of the most famous null results in history. The purpose of the experiment was to prove the existence of "luminiferous aether" considered at the time to be the medium through which light propagated. Students can control the interferometer by changing the speed of light, altering the aether, and rotating the experimental chamber. The results of this experiment provided the first clear demonstration that the "aether drag theory" was seriously flawed.
Fowler, Michael; Welch, Heather
Youth with Visual Impairments: Experiences in General Physical Education
ERIC Educational Resources Information Center
The rapid increase in the number of students with visual impairments currently being educated in inclusive general physical education makes it important that physical education instructors know how best to serve them. Assessment of the experiences of students with visual impairments during general physical education classes, knowledge of students'�
Lieberman, Lauren J.; Robinson, Barbara L.; Rollheiser, Heidi
Specimen Alignment Technique for Oblique-Impact Shock Physics Experiments.
National Technical Information Service (NTIS)
The Impact Physics Branch of the U.S. Army Research Laboratory operates a high pressure gas gun for shock physics research. One of the key types of experiments that are routinely performed with this facility is an oblique-impact experiment where the impac...
T. Cline
Atomic physics and synchrotron radiation: The production and accumulation of highly charged ions
Synchrotron radiation can be used to produce highly-charged ions, and to study photoexcitation and photoionization for ions of virtually any element in the periodic table. To date, with few exceptions, atomic physics studies have been limited to rare gases and a few metal vapors, and to photoexcitation energies in the VUV region of the electromagnetic spectrum. These limitations can now be overcome using photons produced by high-brightness synchrotron storage rings, such as the x-ray ring at the National Synchrotron Light Source (NSLS) at Brookhaven. Furthermore, calculations indicate that irradiation of an ion trap with an intense energetic photon beam will result in a viable source of highly-charged ions that can be given the name PHOBIS: the PHOton Beam Ion Source. Promising results, which encourage the wider systematic use of synchrotron radiation in atomic physics research, have been obtained in recent experiments on VUV photoemission and the production and storage of multiply-charged ions. 26 refs., 4 figs., 1 tab.
Johnson, B.M.; Meron, M.; Agagu, A.; Jones, K.W.
Current experiments in elementary particle physics. Revision 1-85
This report contains summaries of 551 approved experiments in elementary particle physics (experiments that finished taking data before 1 January 1980 are excluded). Included are experiments at Brookhaven, CERN, CESR, DESY, Fermilab, Moscow Institute of Theoretical and Experimental Physics, Tokyo Institute of Nuclear Studies, KEK, LAMPF, Leningrad Nuclear Physics Institute, Saclay, Serpukhov, SIN, SLAC, and TRIUMF, and also experiments on proton decay. Properties of the fixed-target beams at most of the laboratories are summarized. Instructions are given for searching online the computer database (maintained under the SLAC/SPIRES system) that contains the summaries.
Wohl, C.G.; Armstrong, F.E.; Rittenberg, A.; Trippe, T.G.; Yost, G.P.; Oyanagi, Y.; Dodder, D.C.; Grudtsin, S.N.; Ryabov, Yu.G.; Frosch, R.
Atomic Collision Experiments with Ultra-Low-Energy Antiprotons
NASA Astrophysics Data System (ADS)
We have developed techniques to decelerate, cool and confine antiprotons in vacuo with an electromagnetic trap, for production of a Monoenergetic Ultra-Slow Antiproton Source for High-precision Investigation (MUSASHI) over the last several years. The ultra-slow antiproton beam which can now be extracted stably has opened up the possibility to study ionization and atomic capture processes between an antiproton and an atom at an unprecedented low energy under the single-collision condition for the first time. The collision energy can be tuned from 10 eV to 1 keV either by varying the beam transport energy or by biasing the voltages at the collision region. Since the number of available antiprotons is very much limited, the reaction probability must be maximized in order to make best use of them. We have prepared a powerful supersonic helium gas jet with a density of 3�1012 atoms/cm3 to be crossed with the antiproton beam. For rigorous identification of particles (e-, p and (pA+)0) needed for reduction of huge background signals, we developed a detection system with two microchannel plates each with a delay-line two-dimensional position sensitive detector, and a box of scintillator plates. A set of electrodes and coils were placed near the collision point to guide electromagnetically the electrons perpendicular to the antiproton beam. The reaction events will be recognized by an electron signal followed by an antiproton annihilation with an appropriate time of flight. Our design and strategy of the experiment are discussed.
Torii, Hiroyuki A.; Nagata, Yugo; Imao, Hiroshi; Varentsov, Victor L.; Kuroda, Naofumi; Shibata, Masahiro; Ogata, Koremitsu; Toyoda, Hiroshi; Shimoyama, Takuya; Enomoto, Yoshinori; Higaki, Hiroyuki; Kanai, Yasuyuki; Mohri, Akihiro; Yamazaki, Yasunori
Coherent backscattering of light by cold atoms: Theory meets experiment
Coherent backscattering (CBS) of quasi-resonant light by cold atoms presents some specific features due to the internal structure of the atomic scatterers. We present the first quantitative comparison between the experimentally observed CBS cones and Monte Carlo calculations which take into account the shape of the atomic cloud as well as the internal atomic structure.
G. Labeyrie; D. Delande; C. A. M�ller; C. Miniatura; R. Kaiser
NASA physics and chemistry experiments in-space program
NASA Technical Reports Server (NTRS)
The Physics and Chemistry Experiments Program (PACE) is part of the Office of Aeronautics and Space Technology (OAST) research and technology effort in understanding the fundamental characteristics of physics and chemical phenomena. This program seeks to increase the basic knowledge in these areas by well-planned research efforts which include in-space experiments when the limitations of ground-based activities precludes or restricts the achievement of research goals. Overview study areas are concerned with molecular beam experiments for Space Shuttle, experiments on drops and bubbles in a manned earth-orbiting laboratory, the study of combustion experiments in space, combustion experiments in orbiting spacecraft, gravitation experiments in space, and fluid physics, thermodynamics, and heat-transfer experiments. Procedures for the study program have four phases. An overview study was conducted in the area of materials science.
Gabris, E. A.
ATOMIC AND MOLECULAR PHYSICS: Lithium atom population transfer by population trapping in a chirped microwave pulse
Using a time-dependent multilevel approach, we demonstrate that lithium atoms can be transferred to states of lower principle quantum number by exposing them to a frequency chirped microwave pulse. The population transfer from n = 79 to n = 70 states of lithium atoms with more than 80% efficiency is achieved by means of the sequential two-photon Deltan = -1
Guang-Rui Jia; Xian-Zhou Zhang; Zhen-Zhong Ren; Su-Ling Wu
ATOMIC AND MOLECULAR PHYSICS: Numerical exploration of population transfer of Rydberg-atom by single frequency-chirped laser pulse
This paper has calculated that Rydberg atoms can be transferred to states of lower principal quantum number by exposing them to a frequency chirped microwave pulse. The atoms experience the consequence: 70p-69s-68p-67s-66p by a constant amplitude field in the adopted model. This study shows that the complete population transfer is related to the chirp rate and the carrier frequency.
Xian-Zhou Zhang; Zhen-Zhong Ren; Guang-Rui Jia; Xiao-Tian Guo; Wei-Gui Gong
Nuclear Physics Experiments Below The Coulomb Barrier
In 1932, Cockcroft and Walton showed that (p,{alpha}) reactions with lithium were possible at energies near 100 keV. We report an undergraduate laboratory experiment with 90 keV protons colliding with a thick lithium target. The experiment allows students to observe the products of two reactions, to determine the product masses, and to learn techniques for deconvolving experimental spectra profiles.
Sanders, J. M.; Clark, R. K. [Department of Physics, ILB 115, University of South Alabama, Mobile, AL, 36608 (United States); Cifuentes, J. R. Morales [Department of Physics, ILB 115, University of South Alabama, Mobile, AL, 36608 (United States); Department of Physics, University of Maryland, College Park, MD, 20742 (United States)
Learning Pathways in High-School Level Quantum Atomic Physics.
ERIC Educational Resources Information Center
Investigations of changes in conceptions during physics instruction are the logical and necessary steps to follow successful international research on students' preinstructional conceptions. The theoretical perspective integrates currently available frameworks of cognition, cognitive states, and cognitive processes in physics. Particular emphasis�
Niedderer, Hans; Petri, Juergen
Ground Control to Niels Bohr: Exploring Outer Space with Atomic Physics
We provided an introduction to transition state theory and the connections it provides between atomic and celestial physics. We include brief discussions of historical background, recent applications in space mission design, and current research efforts.
Mason A. Porter; Predrag Cvitanovic
Summary of informal workshop on state of ion beam facilities for atomic physics research
The present state of ion beam facilities for atomic physics research in the United States is assessed by means of a questionnaire and informal workshop. Recommendations for future facilities are given. 3 refs.
Jones, K.W.; Cocke, C.L.; Datz, S.; Kostroun, V.
Request for Support for the Conference on Super Intense Laser Atom Physics
The Conference on Super Intense Laser Atom Physics (SILAP) was held in November 2003 in Dallas, Texas. The venue for the meeting was South Fork Ranch in the outskirts of Dallas. The topics of the meeting included high harmonic generation and attosecond pulse generation, strong field interactions with molecules and clusters, particle acceleration, and relativistic laser atom interactions.
Todd Ditmire
Solution Calorimetry Experiments for Physical Chemistry.
ERIC Educational Resources Information Center
Presents two experiments: the first one measures the heat of an exothermic reaction by the reduction of permanganate by the ferris ion; the second one measures the heat of an endothermic process, the mixing of ethanol and cyclohexane. Lists tables to aid in the use of the solution calorimeter. (MVL)
Raizen, Deborah A.; And Others
Using the Wiimote in Introductory Physics Experiments
ERIC Educational Resources Information Center
The Wii is a very popular gaming console. An important component of its appeal is the ease of use of its remote controller, popularly known as a Wiimote. This simple-looking but powerful device has a three-axis accelerometer and communicates with the console via Bluetooth protocol. We present two experiments that demonstrate the feasibility of�
Ochoa, Romulo; Rooney, Frank G.; Somers, William J.
Solid Hydrogen Experiments for Atomic Propellants: Image Analyses
NASA Technical Reports Server (NTRS)
This paper presents the results of detailed analyses of the images from experiments that were conducted on the formation of solid hydrogen particles in liquid helium. Solid particles of hydrogen were frozen in liquid helium, and observed with a video camera. The solid hydrogen particle sizes, their agglomerates, and the total mass of hydrogen particles were estimated. Particle sizes of 1.9 to 8 mm (0.075 to 0.315 in.) were measured. The particle agglomerate sizes and areas were measured, and the total mass of solid hydrogen was computed. A total mass of from 0.22 to 7.9 grams of hydrogen was frozen. Compaction and expansion of the agglomerate implied that the particles remain independent particles, and can be separated and controlled. These experiment image analyses are one of the first steps toward visually characterizing these particles, and allow designers to understand what issues must be addressed in atomic propellant feed system designs for future aerospace vehicles.
Palaszewski, Bryan
Are Atom-sized X-ray Experiments Possible?
The success of advanced microbeam facilities at third generation synchrotron sources have inspired us to ask ultimate questions such as how small an x-ray beam diameter can be made. With the hope of more brilliant Energy Recovery Linac or X-ray Free Electron Laser sources due to arrive in the next decade, it appears possible to think of fluorescent x-ray experiments that can be performed on even a single impurity atom in a silicon wafer, for instance. Not all x-ray optical developers are yet convinced, however, so there is critical need to assess whether in principle this can really be done or not. We are optimistic that 1 nm diameter x-ray beams can be made of sufficient flux from future sources or even demonstration experiments at lower count rates from 3rd generation sources if it turns out to be worthwhile to actively develop optics and methods that vastly exceed the current x-ray microbeam capabilities.
Bilderback, Donald H. [Cornell High Energy Synchrotron Source (CHESS), Cornell University, Ithaca, NY 14853 (United States); School of Applied and Engineering Physics, Cornell University, Ithaca, NY 14853 (United States); Huang Rong [Cornell High Energy Synchrotron Source (CHESS), Cornell University, Ithaca, NY 14853 (United States)
Physics of Hard Spheres Experiment: Significant and Quantitative Findings Made
NASA Technical Reports Server (NTRS)
Direct examination of atomic interactions is difficult. One powerful approach to visualizing atomic interactions is to study near-index-matched colloidal dispersions of microscopic plastic spheres, which can be probed by visible light. Such spheres interact through hydrodynamic and Brownian forces, but they feel no direct force before an infinite repulsion at contact. Through the microgravity flight of the Physics of Hard Spheres Experiment (PHaSE), researchers have sought a more complete understanding of the entropically driven disorder-order transition in hard-sphere colloidal dispersions. The experiment was conceived by Professors Paul M. Chaikin and William B. Russel of Princeton University. Microgravity was required because, on Earth, index-matched colloidal dispersions often cannot be density matched, resulting in significant settling over the crystallization period. This settling makes them a poor model of the equilibrium atomic system, where the effect of gravity is truly negligible. For this purpose, a customized light-scattering instrument was designed, built, and flown by the NASA Glenn Research Center at Lewis Field on the space shuttle (shuttle missions STS 83 and STS 94). This instrument performed both static and dynamic light scattering, with sample oscillation for determining rheological properties. Scattered light from a 532- nm laser was recorded either by a 10-bit charge-coupled discharge (CCD) camera from a concentric screen covering angles of 0 to 60 or by sensitive avalanche photodiode detectors, which convert the photons into binary data from which two correlators compute autocorrelation functions. The sample cell was driven by a direct-current servomotor to allow sinusoidal oscillation for the measurement of rheological properties. Significant microgravity research findings include the observation of beautiful dendritic crystals, the crystallization of a "glassy phase" sample in microgravity that did not crystallize for over 1 year in 1g (Earth's gravity), and the emergence of face-centered-cubic (FCC) crystals late in the coarsening process (as small crystallites lost particles to the slow ripening of large crystallites). Significant quantitative findings from the microgravity experiments have been developed describing complex interactions among crystallites during the growth process, as concentration fields overlap in the surrounding disordered phase. Time-resolved Bragg scattering under microgravity captures one effect of these interactions quite conclusively for the sample at a volume fraction of 0.528. From the earliest time until the sample is almost fully crystalline, the size and overall crystallinity grow monotonically, but the number of crystallites per unit volume (number density) falls. Apparently nucleation is slower than the loss of crystallites because of the transfer of particles from small to large crystals. Thus, coarsening occurs simultaneously with growth, rather than following the completion of nucleation and growth as is generally assumed. In the same sample, an interesting signature appears in the apparent number density of crystallites and the volume fraction within the crystallites shortly before full crystallinity is reached. A brief upturn in both indicates the creation of more domains of the size of the average crystallite simultaneous with the compression of the crystallites. Only the emergence of dendritic arms offers a reasonable explanation. The arms would be "seen" by the light scattering as separate domains whose smaller radii of curvature would compress the interior phase. In fiscal year 1999, numerous papers, a doctoral dissertation, and the PHaSE final report were produced. Although this flight project has been completed, plans are in place for a follow-on colloid experiment by Chaikin and Russel that employs a light microscope within Glenn's Fluids and Combustion Facility on the International Space Station. PHaSE is providing us with a deeper understanding of the nure of phase transitions. The knowledge derived has added to the understandin
Doherty, Michael P.
Atomic and molecular physics in the gas phase
The spatial and temporal distributions of energy deposition by high-linear-energy-transfer radiation play an important role in the subsequent chemical and biological processes leading to radiation damage. Because the spatial structures of energy deposition events are of the same dimensions as molecular structures in the mammalian cell, direct measurements of energy deposition distributions appropriate to radiation biology are infeasible. This has led to the development of models of energy transport based on a knowledge of atomic and molecular interactions process that enable one to simulate energy transfer on an atomic scale. Such models require a detailed understanding of the interactions of ions and electrons with biologically relevant material. During the past 20 years there has been a great deal of progress in our understanding of these interactions; much of it coming from studies in the gas phase. These studies provide information on the systematics of interaction cross sections leading to a knowledge of the regions of energy deposition where molecular and phase effects are important and that guide developments in appropriate theory. In this report studies of the doubly differential cross sections, crucial to the development of stochastic energy deposition calculations and track structure simulation, will be reviewed. Areas of understanding are discussed and directions for future work addressed. Particular attention is given to experimental and theoretical findings that have changed the traditional view of secondary electron production for charged particle interactions with atomic and molecular targets.
Toburen, L.H.
Determination of Spin-Lattice Relaxation of Time Using (Super 13)C NMR: An Undergraduate Physical Chemistry Laboratory Experiment
ERIC Educational Resources Information Center
An experiment designed for the physical chemistry laboratory where (super 13)C NMR is applied to determine the spin-lattice relaxation time for carbon atoms in n-hexanol is proposed. It is concluded that students learn the principles and concepts of NMR spectroscopy as well as dynamic NMR experiments.
Gasyna, Zbigniew L.; Jurkiewicz, Antoni
Lithium atom interferometer using laser diffraction: description and experiments
We have built and operated an atom interferometer of the Mach-Zehnder type. The atomic wave is a supersonic beam of lithium seeded in argon and the mirrors and beam-splitters for the atomic wave are based on elastic Bragg diffraction on laser standing waves at ? = 671 nm. We give here a detailed description of our experimental setup and of
A. Miffre; M. Jacquey; M. Buchner; G. Trenec; J. Vigue
Ground-based laboratory atomic oxygen calibration experiments
NASA Astrophysics Data System (ADS)
Existing devices and analysis techniques for the monitoring of space and laboratory simulated Atomic Oxygen (AO) environments have been investigated and improved to enable more accurate and reliable measurement and calibration of AO flux and fluences than previously possible. This research was based on experimental work carried out in a ground based AO facility designed to simulate the low Earth orbit (LEO) AO space environment, an environment which contributes significantly to the degradation of spacecraft materials. Three types of AO measuring device, referred to as 'silver film', 'bulk polymer mass loss' and 'polymer overlay' devices, were used in the experiments and were based on the following principles for detection of AO, respectively: (1) The electrical resistivity characteristics of oxidising, thin silver films. (2) The mass loss of bulk polymeric materials. (3) The combination of both the above phenomena. In calibrating the responses of these devices upon exposure to AO, it was necessary to improve an existing technique to establish reference measurements of AO fluences based on the mass loss of the polymeric material 'Kapton-H'. Experiments showed that the most significant disturbance factor affecting accurate measurements of mass loss was atmospheric humidity, which was found to be responsible for a disturbance of 0.012(�0.002)mg per percent change in atmospheric humidity level for the particular samples used in this research. Experiments also revealed a novel technique which indicated the relative stability of conditions within a simulated AO environment by the ratio of mass losses of a set of polymeric test samples, including polyethylene, polytetrafluoroethylene and Kapton-H, described as a 'signature analysis technique'. Interactions occurring between AO and a variety of polyethylene related polymeric materials were shown to be influenced by the methods used to manufacture and process the polymers. This influence has been related to changes in polymeric material density and crystallinity. In addition, the limitations in protecting a polymeric material from AO erosion by insertion of fluorine into the side-chain group chemistry has been indicated. Of most significance to the development of polymer overlay devices was the discovery that the overlay material AO erosion yield was dependent upon the rate at which the polymer overlay material was sputter deposited. These devices were also shown to detect AO fluences that were linearly dependent upon the initial thickness of the overlay material up to certain thicknesses, beyond which the effects of overlay porosity or fracturing weakened the linear relationship. A novel method for analysing silver film device electrical resistances under AO exposure has been developed from a combination of existing fundamental theories concerning the electrical resistivity phenomena in thin metallic films. Validation of this analysis method revealed that experimental silver film data were consistently in disagreement with the existing theories due to a factor influencing the conduction electron mean free path length in the silver films. Final validation of this analysis technique was performed by comparing results derived from the same set of experimental silver film device data using the new technique and an example of a previous technique. It was confirmed that the novel analysis technique produced far more consistent values for the oxidation yield of silver, 3/pm0.5�10-24cm3.atom-1, than the previously used technique, 6/pm3�10- 24cm3.atom-1. The novel analysis technique has been demonstrated to be theoretically more accurate for the analysis of silver film resistance data than any previously applied theories.
Matcham, Jeremy Stephen
Physics Analysis of the FIRE Experiment
An integrated model of a complete discharge in the FIRE experiment has been developed based on the TSC simulation code. The complete simulation model includes a choice of several models for core transport, combined with an edge pedestal model and the Porcelli sawtooth model. Burn control is provided by feedback on the auxiliary heating power. We find that with the GLF23 and MMM95 transport models, Q >10 operation should be possible for H-mode pedestal temperatures in the range of 4-5 keV.
S.C. Jardin; C.E. Kessel; D. Meade; J. Breslau; G. Fu; N. Gorelenkov; J. Manickam; W. Park; H. Strauss
Project Physics Handbook 5, Models of the Atom.
ERIC Educational Resources Information Center
Five experiments and 19 activities are presented in this Unit 5 handbook. The experiments are related to electrolysis, charge-to-mass ratio, elementary charge determination, photoelectric effects, and spectroscopic analyses. The activities are concerned with Dalton's theory, water electrolysis, periodic tables, single-electron plating, cloud�
Harvard Univ., Cambridge, MA. Harvard Project Physics.
Current experiments in elementary-particle physics - March 1983
Microfiche are included which contain summaries of 479 experiments in elementary particle physics. Experiments are included at the following laboratories: Brookhaven (BNL); CERN; CESR; DESY; Fermilab (FNAL); Institute for Nuclear Studies (INS); KEK; LAMPF; Serpukhov (SERP); SIN; SLAC; and TRIUMF. Also, summaries of proton decay experiments are included. A list of experiments and titles is included; and a beam-target-momentum index and a spokesperson index are given. Properties of beams at the facilities are tabulated. (WHK)
Wohl, C.G.; Armstrong, F.E.; Rittenberg, A.
Combustion, Complex Fluids, and Fluid Physics Experiments on the ISS.
National Technical Information Service (NTIS)
From the very early days of human spaceflight, NASA has been conducting experiments in space to understand the effect of weightlessness on physical and chemically reacting systems. NASA Glenn Research Center (GRC) in Cleveland, Ohio has been at the forefr...
B. Motil D. Urban
Combustion, Complex Fluids, and Fluid Physics Experiments on the ISS.
National Technical Information Service (NTIS)
From the very first days of human spaceflight, NASA has been conducting experiments in space to understand the effect of weightlessness on physical and chemically reacting systems. NASA Glenn Research Center (GRC) in Cleveland, Ohio has been at the forefr...
B. Motil D. Urban
Simulation of Physical Experiments in Immersive Virtual Environments.
National Technical Information Service (NTIS)
An object-oriented event-driven immersive Virtual environment is described for the creation of virtual labs (VLs) for simulating physical experiments. Discussion focuses on a number of aspects of the VLs, including interface devices, software objects, and...
A. K. Noor T. M. Wasfy
Simple Experiments on the Physics of Vision: The Retina
ERIC Educational Resources Information Center
Many simple experiments can be performed in the classroom to explore the physics of vision. Students can learn of the two types of receptive cells (rods and cones), their distribution on the retina and the existence of the blind spot.
Cortel, Adolf
Using Microcomputers in the Physical Chemistry Laboratory: Activation Energy Experiment.
ERIC Educational Resources Information Center
Describes a computer program, "Activation Energy," which is designed for use in physical chemistry classes and can be modified for kinetic experiments. Provides suggestions for instruction, sample program listings, and information on the availability of the program package. (ML)
Touvelle, Michele; Venugopalan, Mundiyath
Divertor design for the Tokamak Physics Experiment
In this paper we discuss the present divertor design for the planned TPX tokamak, which will explore the physics and technology of steady-state (1000s pulses) heat and particle removal in high confinement (2--4{times} L-mode), high beta ({beta}{sub N} {ge} 3) divertor plasmas sustained by non-inductive current drive. The TPX device will operate in the double-null divertor configuration, with actively cooled graphite targets forming a deep (0.5 m) slot at the outer strike point. The peak heat flux on, the highly tilted (74{degrees} from normal) re-entrant (to recycle ions back toward the separatrix) will be in the range of 4--6 MW/m{sup 2} with 18 MW of neutral beams and RF heating power. The combination of active pumping and gas puffing (deuterium plus impurities), along with higher heating power (45 MW maximum) will allow testing of radiative divertor concepts at ITER-like power densities.
Hill, D.N. [Lawrence Livermore National Lab., CA (United States); Braams, B. [New York Univ., NY (United States). Courant Inst.; Brooks, J.N. [Argonne National Lab., IL (United States)
Stars and statistical physics: A teaching experience
NSDL National Science Digital Library
The physics of stars is a goldmine of problems in statistical mechanics and thermodynamics. We discuss many examples that illustrate the possibility of deepening student�s knowledge of statistical mechanics by an introductory study of stars. The matter constituting the various stellar objects provides examples of equations of state for classical or quantum and relativistic or non-relativistic gases. Maximum entropy can be used to characterize thermodynamic and gravitational equilibrium which determines the structure of stars and predicts their instability above a certain mass. Contraction accompanying radiation induces either heating or cooling, which explains the formation of stars above a minimum mass. The characteristics of the emitted light are understood from blackbody radiation and from the Boltzmann�Lorentz kinetic equation for photons. The luminosity is governed by the transport of heat by photons from the center to the surface. Heat production by thermonuclear fusion is determined by microscopic balance equations. The stability of the steady state of stars is controlled by the interplay of thermodynamics and gravitation.
Balian, Roger; Blaizot, Jean-Paul
Synthesis and Physical Properties of Liquid Crystals: An Interdisciplinary Experiment
ERIC Educational Resources Information Center
A study involves multiple chemistry and physics concepts applied to a state of matter that has biological relevance. An experiment involving the synthesis and physical properties of liquid crystals illustrates the interdisciplinary nature of liquid crystal research and the practical devices derived from such research.
Van Hecke, Gerald R.; Karukstis, Kerry K.; Hanhan Li; Hendargo, Hansford C.; Cosand, Andrew J.; Fox, Marja M.
Project Physics Teacher Guide 5, Models of the Atom.
ERIC Educational Resources Information Center
Teaching procedures of Project Physics Unit 5 are presented to help teachers make effective use of learning materials. Unit contents are discussed in connection with teaching aid lists, multi-media schedules, schedule blocks, and resource charts. Brief summaries are made for transparencies, 16mm films, and reader articles. Included is information�
Harvard Univ., Cambridge, MA. Harvard Project Physics.
Atomic physics with highly-charged ions at the future FAIR facility: A status report
NASA Astrophysics Data System (ADS)
The key features of the future international accelerator Facility for Antiproton and Ion Research (FAIR) offer a range of new and challenging opportunities for atomic physics research in the realm of highly-charged heavy ions and exotic nuclei. Centred on use of FAIR, the Stored Particle Atomic Physics Research Collaboration (SPARC), organized in working groups, has been formed. A short report on the tasks and activities of the various SPARC working groups, devoted to the realization of experimental equipments and set-ups required to reach the physics goals is given.
St�hlker, Th.; Beyer, H. F.; Br�uning, H.; Br�uning-Demian, A.; Brandau, C.; Hagmann, S.; Kozhuharov, C.; Kluge, H. J.; K�hl, Th.; Liesen, D.; Mann, R.; N�rtersh�user, W.; Quint, W.; Schramm, U.; Schuch, R.; SPARC Collaboration
New experiments on few-electron very heavy atoms
New experiments, to test quantum electrodynamics (QED) in strong Coulomb fields and to study atomic collisions at ultrarelativistic energies, are proposed. A 0.1% measurement of the 2/sup 2/P/sub 1/2/-2/sup 2/S/sub 1/2/ splitting in lithium like uranium (Z=92) and the 2/sup 3/P/sub 0/ - 2/sup 3/S/sub 1/ splitting in heliumlike uranium is proposed as a sub 1% test of the Lamb shift in a strong Coulomb field. Measurements of the hyperfine splitting of hydrogenlike thallium (Z=81) and the g/sub j/ factor of the ground state of hydrogenlike uranium are propsed as a test of the QED contribution to the magnetic moment of an electron bound in a strong Coulomb field. Measurements of capture cross sections for ultra relativistic very heavy nuclei are proposed to look for the capture of electrons from pair production. 40 refs., 7 figs., 2 tabs.
Gould, H.
Atomic physics at the future facility for antiproton and ion research: a status report
NASA Astrophysics Data System (ADS)
The new international accelerator Facility for Antiproton and Ion Research (FAIR) which is currently under construction in Darmstadt has key features that offer a wide range of exciting new opportunities in the field of atomic physics and related fields. The facility will provide highest intensities of relativistic beams of both stable and unstable heavy nuclei, in combination with the strong electromagnetic fields generated by high-power lasers, thus allowing to widen atomic physics research into completely new domains. In the current contribution, a short overview of the SPARC (Stored Particle Atomic physics Research Collaboration) research programme at the FAIR facility is given. Furthermore, we present the current strategy for the realization of the envisioned SPARC physics programme at the modularized start version of the FAIR facility.
Gumberidze, A.;
Lithium atom interferometer using laser diffraction: description and experiments
.��We have built and operated an atom interferometer of the\\u000aMach-Zehnder type. The atomic wave is a supersonic beam of lithium\\u000aseeded in argon and the mirrors and beam-splitters for the atomic\\u000awave are based on elastic Bragg diffraction on laser standing\\u000awaves at =671�nm. We give here a detailed description of\\u000aour experimental set-up and of the procedures used
Alain Miffre; Marion Jacquey; M. B�chner; G. Tr�nec; J. Vigu�
Hyperthermal atomic oxygen source for near-space simulation experiments
A hyperthermal atomic oxygen (AO) beam facility has been developed to investigate the collisions of high-velocity AO atoms with vapor-phase counterflow. Application of 4.5 kW, 2.4 GHz microwave power in the source chamber creates a continuous discharge in flowing O{sub 2} gas. The O{sub 2} feedstock is introduced into the source chamber in a vortex flow to constrain the plasma to the center region, with the chamber geometry promoting resonant excitation of the TM{sub 011} mode to localize the energy deposition in the vicinity of the aluminum nitride (AlN) expansion nozzle. The approximately 3500 K environment serves to dissociate the O{sub 2}, resulting in an effluent consisting of 40% AO by number density. Downstream of the nozzle, a silicon carbide (SiC) skimmer selects the center portion of the discharge effluent, prior to the expansion reaching the first shock front and rethermalizing, creating a beam with a derived 2.5 km s{sup -1} velocity. Differential pumping of the skimmer chamber, an optional intermediate chamber and reaction chamber maintains a reaction chamber pressure in the mid-10{sup -6} to mid-10{sup -5} Torr range. The beam has been characterized with regard to total AO beam flux, O{sub 2} dissociation fraction, and AO spatial profile using time-of-flight mass spectrometric and Kapton-H erosion measurements. A series of reactions AO+C{sub n}H{sub 2n} (n=2-4) has been studied under single-collision conditions using mass spectrometric product detection, and at higher background pressure detecting dispersed IR emissions from primary and secondary products using a step-scan Michelson interferometer. In a more recent AO crossed-beam experiment, number densities and predicted IR emission intensities have been modeled using the direct simulation Monte Carlo technique. The results have been used to guide the experimental conditions. IR emission intensity predictions are compared to detected signal levels to estimate absolute reaction cross sections.
Dodd, James A.; Baker, Paul M.; Hwang, Eunsook S.; Sporleder, David; Stearns, Jaime A. [Space Vehicles Directorate, Air Force Research Laboratory, Hanscom AFB, Massachusetts 01731 (United States); Chambreau, Steven D. [Propulsion Directorate, Air Force Research Laboratory, Edwards AFB, California 93524 (United States); Braunstein, Matthew; Conforti, Patrick F. [Spectral Sciences, Inc., 4 Fourth Ave., Burlington, Massachusetts 01803 (United States)
Hyperthermal atomic oxygen source for near-space simulation experiments.
A hyperthermal atomic oxygen (AO) beam facility has been developed to investigate the collisions of high-velocity AO atoms with vapor-phase counterflow. Application of 4.5 kW, 2.4 GHz microwave power in the source chamber creates a continuous discharge in flowing O(2) gas. The O(2) feedstock is introduced into the source chamber in a vortex flow to constrain the plasma to the center region, with the chamber geometry promoting resonant excitation of the TM(011) mode to localize the energy deposition in the vicinity of the aluminum nitride (AlN) expansion nozzle. The approximately 3500 K environment serves to dissociate the O(2), resulting in an effluent consisting of 40% AO by number density. Downstream of the nozzle, a silicon carbide (SiC) skimmer selects the center portion of the discharge effluent, prior to the expansion reaching the first shock front and rethermalizing, creating a beam with a derived 2.5 km s(-1) velocity. Differential pumping of the skimmer chamber, an optional intermediate chamber and reaction chamber maintains a reaction chamber pressure in the mid-10(-6) to mid-10(-5) Torr range. The beam has been characterized with regard to total AO beam flux, O(2) dissociation fraction, and AO spatial profile using time-of-flight mass spectrometric and Kapton-H erosion measurements. A series of reactions AO+C(n)H(2n) (n=2-4) has been studied under single-collision conditions using mass spectrometric product detection, and at higher background pressure detecting dispersed IR emissions from primary and secondary products using a step-scan Michelson interferometer. In a more recent AO crossed-beam experiment, number densities and predicted IR emission intensities have been modeled using the direct simulation Monte Carlo technique. The results have been used to guide the experimental conditions. IR emission intensity predictions are compared to detected signal levels to estimate absolute reaction cross sections. PMID:19791929
Dodd, James A; Baker, Paul M; Hwang, Eunsook S; Sporleder, David; Stearns, Jaime A; Chambreau, Steven D; Braunstein, Matthew; Conforti, Patrick F
Compilation of current high-energy physics experiments
This is the fourth edition of the compilation of current high energy physics experiments. It is a collaborative effort of the Berkeley Particle Data Group, the SLAC library, and nine participating laboratories: Argonne (ANL), Brookhaven (BNL), CERN, DESY, Fermilab (FNAL), the Institute for Nuclear Study, Tokyo (INS), KEK, Serpukhov (SERP), and SLAC. The compilation includes summaries of all high energy physics experiments at the above laboratories that (1) were approved (and not subsequently withdrawn) before about April 1981, and (2) had not completed taking of data by 1 January 1977. Only approved experiments are included.
Wohl, C.G.; Kelly, R.L.; Armstrong, F.E.
Introducing New Experiments to the Contemporary Physics Lab: Emphasis on Quantum Mechanics Foundations and New Physics Frontiers
NASA Astrophysics Data System (ADS)
We remodeled our sophomore curriculum extensively both in the laboratories and the lectures. Our Experimental Contemporary Physics laboratory (PHY293) was almost completely re-built both in curriculum and pedagogy. Among the new experiments that we introduced are Nanoparticle plasmon resonance, Saturated absorption and fluorescence in iodine molecules, Quantized conductance in atomic-scale constrictions, and Water droplets behavior and manipulation on metal surfaces. This presentation will focus on the last two experiments. Quantized conductance in a constriction in a gold wire being pulled slowly is a unique direct application of the one-dimensional potential wells. Unlike most experiments on quantum mechanics that use optics, this experiment is transport-based, conceptually simple, and robust in addition to being low-cost. The transport properties of the wire span multiple transport regimes while being pulled. It is quite valuable for students (a significant fraction of whom are biological physics and engineering physics majors) to understand the behavior of water droplets on different surfaces. Water is the medium in which biological activities occur and is important in many other applications like air conditioning and refrigeration. We design simple gradients in the hydrophobic/hydrophilic properties of metal surfaces in order to move water droplets in a controlled way, even against gravity. Students explore the effects of surface tension and metal roughness on droplets.
Eid, Khalid; Yarrison-Rice, Jan; Jaeger, Herbert
Atomic physics with highly-charged heavy ions at the GSI future facility: The scientific program of the SPARC collaboration
NASA Astrophysics Data System (ADS)
In the current report a short overview about the envisioned program of the atomic physics research collaboration SPARC (Stored Particle Atomic Research Collaboration, at the new international accelerator Facility for Antiproton and Ion Research (FAIR) at GSI is given. In addition, a condensed description of the planned experimental areas devoted to atomic physics research at the new facility is presented.
St�hlker, Th.; Beier, T.; Beyer, H. F.; Bosch, F.; Br�uning-Demian, A.; Gumberidze, A.; Hagmann, S.; Kozhuharov, C.; K�hl, Th.; Liesen, D.; Mann, R.; Mokler, P. H.; Quint, W.; Schuch, R.; Warczak, A.
Polarization spectroscopy of rubidium atoms: Theory and experiment
We present a theoretical and experimental study of polarization spectroscopy of rubidium atoms. All of the populations of the magnetic sublevels were calculated from the rate equations and used in the calculation of the polarization spectroscopy spectra. Using this model, we could generate theoretical line shapes of the polarization spectra on the D2 transitions of rubidium atoms. The experimental results
Huy Diep Do; Geol Moon; Heung-Ryoul Noh
INSPIRE - Premission. [Interactive NASA Space Physics Ionosphere Radio Experiment
NASA Technical Reports Server (NTRS)
The Interactive NASA Space Physics Ionosphere Radio Experiment (INSPIRE) designed to assist in a Space Experiments with Particle Accelerators (SEPAC) project is discussed. INSPIRE is aimed at recording data from a large number of receivers on the ground to determine the exact propagation paths and absorption of radio waves at frequencies between 50 Hz and 7 kHz. It is indicated how to participate in the experiment that will involve high school classes, colleges, and amateur radio operators.
Taylor, William W. L.; Mideke, Michael; Pine, William E.; Ericson, James D.
Computation of Free-Free Transitions in Atomic Physics: Foundations
NASA Technical Reports Server (NTRS)
The amplitude T for "free-free" processes, such as bremsstrahlung or photo- absorption by an electron in the continuum in the presence of an external field, is usually written as the matrix element of the radiation operator taken between two continuum states. However, unlike the case when at least one of the states is bound, as in radiative transitions, electron capture, or the photo-effect, this expression contains an unphysical term, proportional to a delta-function and is not really the physical amplitude Tphys. This continues to be true for both the velocity and length form of the dipole approximation to the amplitude T. We first give an a priori definition of Tphys in terms of the scattering parts of the continuum functions, which has an obvious interpretation in terms of time-ordered diagrams. We then show that when the formal amplitude is modified by a long- distance cutoff, the modified form approaches Tphys as the cutoff is removed. The modified form then serves as a basis for the definition of a physical velocity dipole amplitude and this in turn leads to an equivalent length form of the dipole amplitude. This exercise provides a clear theoretical basis for many extant calculations in which cutoff factors are introduces somewhat ad hoc, as needed.
Bhatia, A. K.; Sucher, J.
Atom chip apparatus for experiments with ultracold rubidium and potassium gases.
We present a dual chamber atom chip apparatus for generating ultracold (87)Rb and (39)K atomic gases. The apparatus produces quasi-pure Bose-Einstein condensates of 10(4) (87)Rb atoms in an atom chip trap that features a dimple and good optical access. We have also demonstrated production of ultracold (39)K and subsequent loading into the chip trap. We describe the details of the dual chamber vacuum system, the cooling lasers, the magnetic trap, the multicoil magnetic transport system, the atom chip, and two optical dipole traps. Due in part to the use of light-induced atom desorption, the laser cooling chamber features a sufficiently good vacuum to also support optical dipole trap-based experiments. The apparatus is well suited for studies of atom-surface forces, quantum pumping and transport experiments, atom interferometry, novel chip-based traps, and studies of one-dimensional many-body systems. PMID:24784588
Ivory, M K; Ziltz, A R; Fancher, C T; Pyle, A J; Sensharma, A; Chase, B; Field, J P; Garcia, A; Jervis, D; Aubin, S
Complex-Angular-Momentum Analysis of Atom-Atom Scattering Experiments
S-matrix elements typically encountered in atom-atom scattering may be phenomenologically parametrized using meromorphic functions of complex angular momenta. The contribution to the scattering amplitude of each pole of the S matrix is of such a simple nature (effectively, decaying oscillations for parameters encountered in practice) as to greatly facilitate the deduction of the phase shifts from scattering data. Some of
E. A. Remler
Experiences in Sport, Physical Activity, and Physical Education Among Christian, Buddhist, and Hindu Asian Adolescent Girls
Multicultural scholarship in sport and exercise psychology should help us understand and apply cultural competencies for all to be physically active. In the present study, two Asian countries, Japan and Singapore, were chosen. The participation rate for physical activities among adolescent girls tends to be lower than that of boys in both countries. Thus, the purpose of the project was to gain knowledge and understanding about sociocultural factors that may explain adolescent girls' perceptions and behaviors toward sport, physical activity, and physical education (PE). A qualitative approach using semi-structured interviews with focus groups was used to understand meanings of physical activity among Buddhist Japanese, and Hindu Indians and Christian Chinese from Singapore. Each focus group consisted of four or five girls and female researchers. Based on the analysis, we created four themes which were "cultural identities," "Asian girls and sport/physical activities," "PE experiences," "motivation for future involvement." The Buddhist Japanese, Hindu Indian, and Christian Chinese participants each reported unique physical activity experiences, and all the participants were aware of how Asian culture may affect being physically active. Experiences of PE classes were similar but perceptions of their PE attire were different for Christian Chinese and Hindu Indian adolescent girls. Based on the results, the importance of nurturing cultural competencies and ways to encourage girls to be physically active throughout life were discussed.
Kodani, Iku; Gupta, Nidhi; Gill, Diane L.
Proceedings of the workshop on opportunities for atomic physics using slow, highly-charged ions
The study of atomic physics with highly-charged ions is an area of intense activity at the present time because of a convergence of theoretical interest and advances in experimental techniques. The purpose of the Argonne ''Workshop on Opportunities for Atomic Physics Using Slow, Highly-Charged Ions'' was to bring together atomic, nuclear, and accelerator physicists in order to identify what new facilities would be most useful for the atomic physics community. The program included discussion of existing once-through machines, advanced ion sources, recoil ion techniques, ion traps, and cooler rings. One of the topics of the Workshop was to discuss possible improvement to the ANL Tandem-Linac facility (ATLAS) to enhance the capability for slowing down ions after they are stripped to a high-charge state (the Accel/Decel technique). Another topic was the opportunity for atomic physics provided by the ECR ion source which is being built for the Uranium Upgrade of ATLAS. 18 analytics were prepared for the individual papers in this volume.
Not Available
Output from an atom laser: theory vs. experiment
. ��Atom lasers based on rf-outcoupling can be described by a set of coupled generalized Gross�Pitaevskii equations (GPE). We\\u000a compare the theoretical predictions obtained by numerically integrating the time-dependent GPE of an effective one-dimensional\\u000a model with recently measured experimental data for the F=2 and F=1 states of Rb-87. We conclude that the output of a rf atom-laser can be described
Jens Schneider; Axel Schenzle
HISTRAP (Heavy Ion Storage Ring for Atomic Physics) prototype hardware studies
HISTRAP, Heavy Ion Storage Ring for Atomic Physics, is a proposed 2.67-Tm synchrotron/cooler/storage ring optimized for advanced atomic physics research which will be injected with ions from either the HHIRF 25-MV tandem accelerator or a dedicated ECR source and RFQ linac. Over the last two years, hardware prototypes have been developed for difficult and long lead-time components. A vacuum test stand, the rf cavity, and a prototype dipole magnet have been designed, constructed, and tested. 7 refs., 8 figs., 2 tabs.
Olsen, D.K.; Atkins, W.H.; Dowling, D.T.; Johnson, J.W.; Lord, R.S.; McConnell, J.W.; Milner, W.T.; Mosko, S.W.; Tatum, B.A.
The physics analysis tools project for the ATLAS experiment
NASA Astrophysics Data System (ADS)
The Large Hadron Collider is expected to start colliding proton beams in 2009. The enormous amount of data produced by the ATLAS experiment (~1 PB per year) will be used in searches for the Higgs boson and Physics beyond the standard model. In order to meet this challenge, a suite of common Physics Analysis Tools has been developed as part of the Physics Analysis software project. These tools run within the ATLAS software framework, ATHENA, covering a wide range of applications. There are tools responsible for event selection based on analysed data and detector quality information, tools responsible for specific physics analysis operations including data quality monitoring and physics validation, and complete analysis toolkits (frameworks) with the goal to aid the physicist to perform his analysis hiding the details of the ATHENA framework.
Lenzi, Bruno; ATLAS Collaboration
Compilation of current high-energy-physics experiments
This is the third edition of a compilation of current high energy physics experiments. It is a collaborative effort of the Berkeley Particle Data Group, the SLAC library, and ten participating laboratories: Argonne (ANL), Brookhaven (BNL), CERN, DESY, Fermilab (FNAL), the Institute for Nuclear Study, Tokyo (INS), KEK, Rutherford (RHEL), Serpukhov (SERP), and SLAC. The compilation includes summaries of all high energy physics experiments at the above laboratories that (1) were approved (and not subsequently withdrawn) before about January 1980, and (2) had not completed taking of data by 1 January 1976.
Wohl, C.G.; Kelly, R.L.; Armstrong, F.E.
Simulation of Physical Experiments in Immersive Virtual Environments
NASA Technical Reports Server (NTRS)
An object-oriented event-driven immersive Virtual environment is described for the creation of virtual labs (VLs) for simulating physical experiments. Discussion focuses on a number of aspects of the VLs, including interface devices, software objects, and various applications. The VLs interface with output devices, including immersive stereoscopic screed(s) and stereo speakers; and a variety of input devices, including body tracking (head and hands), haptic gloves, wand, joystick, mouse, microphone, and keyboard. The VL incorporates the following types of primitive software objects: interface objects, support objects, geometric entities, and finite elements. Each object encapsulates a set of properties, methods, and events that define its behavior, appearance, and functions. A container object allows grouping of several objects. Applications of the VLs include viewing the results of the physical experiment, viewing a computer simulation of the physical experiment, simulation of the experiments procedure, computational steering, and remote control of the physical experiment. In addition, the VL can be used as a risk-free (safe) environment for training. The implementation of virtual structures testing machines, virtual wind tunnels, and a virtual acoustic testing facility is described.
Noor, Ahmed K.; Wasfy, Tamer M.
Atomic Clocks on Earth and in Space for Tests of Fundamental Physics and Navigation
NASA Astrophysics Data System (ADS)
I review the performance objectives for RACE, the Rubidium Atomic Clock Experiment that was to fly on the International Space Station. RACE's performance could, in addition to significantly advancing clock tests of general relativity and Lorentz invariance, enable precise interplanetary navigation. I will also describe a juggling clock experiment that can sensitively probe interatomic forces at Angstrom ranges.
Gibble, K.
Design, development, and fabrication of a prototype ice pack heat sink subsystem. Flight experiment physical phenomena experiment chest
NASA Technical Reports Server (NTRS)
The concept of a flight experiment physical phenomena experiment chest, to be used eventually for investigating and demonstrating ice pack heat sink subsystem physical phenomena during a zero gravity flight experiment, is described.
Roebelen, G. J., Jr.; Dean, W. C., II
High-energy shadowing effect and its application to atomic and solid state physics
Ion-beam shadowing effects for projectiles in the MeV\\/u energy range have been studied with high-energy (keV) secondary electrons emitted from the surface of a target crystal. This article reviews and discusses applications of the high-energy shadowing effect to atomic and solid state physics, as well as physical and technical aspects of the electron spectroscopy under channeling incidence conditions.
Kudo Hiroshi; Shima Kunihiro; Ishihara Toyoyuki; Takeshita Hidefumi; Aoki Yasushi; Yamamoto Shunya; Naramoto Hiroshi
Young's double-slit experiment with atoms - A simple atom interferometer
An atomic interferometer based on a Young's-type double-slit arrangement has been demonstrated. A supersonic beam of metastable helium atoms passes through a 2-micron-wide slit in a thin gold foil. This transversely coherent beam impinges on a second microfabricated transmission structure, consisting of two 1-micron-wide slits at a lateral distance of 8 microns. This double slit defines two possible paths on
O. Carnal; J. Mlynek
Proceedings of the Workshop on Fundamental Muon Physics: Atoms, Nuclei, and Particles Held at Los Alamos, New Mexico on 20 January 1986.
National Technical Information Service (NTIS)
This report contains the proceedings of a workshop held at Los Alamos, January 20-22, 1986, to discuss present and future experiments with muons in particle, nuclear, and atomic physics. Special attention was paid to new developments in muon beams and det...
C. M. Hoffman V. W. Hughes M. Leon
Toolbar to Highlight Important Expressions in Scientific Articles on Atomic and Molecular Physics
NASA Astrophysics Data System (ADS)
We introduce software that recognizes, extracts, and displays expressions concerning atomic and molecular data from academic papers in the electronic form. This software includes a toolbar application that can be installed in Internet Explorer (IE). This toolbar can be used by scientific readers and researchers to highlight, color-code, and collect important expressions more easily. Those expressions include atomic and molecular symbols (e.g., Xe+ and H2O) and electron configurations(e.g., 4d95s25p) from the atomic and molecular data of a large number of academic papers. We confirmed by experiments that the software could find important expressions with high precision (0.8-1.0). This software is also useful for compiling databases of atomic and molecular data, which is important for plasma simulations, because the simulations critically depend on atomic and molecular data, including the energy levels and collisional and radiative rate coefficients.
Murata, Masaki; Sasaki, Akira; Kanamaru, Toshiyuki; Shirado, Tamotsu; Isahara, Hitoshi
Experimenting in a Constructivist High School Physics Laboratory
NSDL National Science Digital Library
Presents a study involving students (n=46) enrolled in an introductory physics course designed to describe and understand students' experimenting and problem-solving strategies in a constructivist learning environment. Concludes that students should be provided with problem-rich learning environments in which they learn to investigate phenomena of their own interest and can develop complex problem-solving skills.
Roth, Wolff-Michael
Enthalpy of Vaporization by Gas Chromatography: A Physical Chemistry Experiment
ERIC Educational Resources Information Center
An experiment is conducted to measure the enthalpy of vaporization of volatile compounds like methylene chloride, carbon tetrachloride, and others by using gas chromatography. This physical property was measured using a very tiny quantity of sample revealing that it is possible to measure the enthalpies of two or more compounds at the same time.
Ellison, Herbert R.
Multidisciplinary Field Training in Undergraduate Physical Geography: Russian Experience
ERIC Educational Resources Information Center
Field training is seen as a central component of the discipline of Physical Geography and an essential part of the undergraduate curriculum. This paper explores the structure and relationships between fieldwork and theoretical courses and the abundant experiences of field training in the undergraduate curriculum of 37 Russian universities. It�
Kasimov, Nikolay S.; Chalov, Sergey R.; Panin, Andrey V.
Do General Physics Textbooks Discuss Scientists' Ideas about Atomic Structure? A Case in Korea
ERIC Educational Resources Information Center
Research in science education has recognized the importance of teaching atomic structure within a history and philosophy of science perspective. The objective of this study is to evaluate general physics textbooks published in Korea based on the eight criteria developed in previous research. The result of this study shows that Korean general�
Niaz, Mansoor; Kwon, Sangwoon; Kim, Nahyun; Lee, Gyoungho
Ground-based laboratory atomic oxygen calibration experiments
Existing devices and analysis techniques for the monitoring of space and laboratory simulated Atomic Oxygen (AO) environments have been investigated and improved to enable more accurate and reliable measurement and calibration of AO flux and fluences than previously possible. This research was based on experimental work carried out in a ground based AO facility designed to simulate the low Earth
Jeremy Stephen Matcham
Evidence for a rotational rainbow in inelastic hot atom experiments
The rotational population of carbon dioxide,after collision with translationally hot hydrogen atoms has been reported recently(ref.1). It is contended that the population distribution can be explained by a rotational rainbow mechanism for the rotational excitation.(AIP) :m
Bowman, J.M.; Gazdy, B.
Proposed Laser-Based HED physics experiments for Stockpile Stewardship
An analysis of the scientific areas in High Energy Density (HED) physics that underpin the enduring LANL mission in Stockpile Stewardship (SS) has identified important research needs that are not being met. That analysis has included the work done as part of defining the mission need for the High Intensity Laser Laboratory (HILL) LANL proposal to NNSA, LDRD DR proposal evaluations, and consideration of the Predictive Capability Framework and LANL NNSA milestones. From that evaluation, we have identified several specific and scientifically-exciting experimental concepts to address those needs. These experiments are particularly responsive to physics issues in Campaigns 1 and 10. These experiments are best done initially at the LANL Trident facility, often relying on the unique capabilities available there, although there are typically meritorious extensions envisioned at future facilities such as HILL, or the NIF once the ARC short-pulse laser is available at sufficient laser intensity. As the focus of the LANL HEDP effort broadens from ICF ignition of the point design at the conclusion of the National Ignition Campaign, into a more SS-centric effort, it is useful to consider these experiments, which address well-defined issues, with specific scientific hypothesis to test or models to validate or disprove, via unit-physics experiments. These experiments are in turn representative of a possible broad experimental portfolio to elucidate the physics of interest to these campaigns. These experiments, described below, include: (1) First direct measurement of the evolution of particulates in isochorically heated dense plasma; (2) Temperature relaxation measurements in a strongly-coupled plasma; (3) Viscosity measurements in a dense plasma; and (4) Ionic structure factors in a dense plasma. All these experiments address scientific topics of importance to our sponsors, involve excellent science at the boundaries of traditional fields, utilize unique capabilities at LANL, and contribute to the Campaign milestone in 2018. Given their interdisciplinary nature, it is not surprising that these research needs are not being addressed by the other excellent high-energy density physics (HEDP) facilities coming on line, facilities aimed squarely at more established fields and missions. Although energy rich, these facilities deliver radiation (e.g., particle beams for isochoric heating) over a timescale that is too slow in these unit physics experiments to eliminate hydrodynamic evolution of the target plasma during the time it is being created. A theme shared by all of these experiments is the need to quickly create a quasi-homogeneous 'initial state' whose properties and evolution we wish to study. Otherwise, we cannot create unit experiments to isolate the physics of interest and validate the models in our codes, something that cannot be done with the integrated experiments often done in HED. Moreover, these experiments in some cases involve combinations of solid and plasmas, or matter in the warm-dense matter state, where neither the theoretical approximations of solid state or of fully-ionized weakly-coupled plasmas can be used. In all cases, the capability of 'isochoric heating' ('flash' heating at constant density) is important. In some cases, the ability to selectively heat to different degrees different species within a target, whether mixed or adjacent to each other, is critical for the experiment. This capability requires the delivery of very high power densities, which require the conversion of the laser into very short and intense pulses of secondary radiation (electrons, ions, neutrons, x-rays). Otherwise, there is no possibility of a clean experiment to constrain the models, in the cases there are any, or inform the creation of one. Another typical requirement of these experiments is the ability to probe these exotic extreme conditions of matter with flexible and diverse sources of secondary radiation. Without a high-intensity high-power laser with some unique attributes available on Trident today (e.g., ultra-high laser-puls
Benage, John F. [Los Alamos National Laboratory; Albright, Brian J. [Los Alamos National Laboratory; Fernandez, Juan C. [Los Alamos National Laboratory
Accurate measurement and physical insight: The X-ray extended range technique for fundamental atomic physics, condensed matter research and biological sciences
NASA Astrophysics Data System (ADS)
Research in core physics or atomic and condensed matter science is increasingly relevant for diverse fields and are finding application in chemistry, engineering and biological sciences, linking to experimental research at synchrotrons, reactors and specialised facilities. Over recent synchrotron experiments and publications we have developed methods for measuring the absorption coefficient far from the edge and in the XAFS (X-ray absorption fine structure) region in neutral atoms, simple compounds and organometallics reaching accuracies of below 0.02%. This is 50-500 times more accurate than earlier methods, and 50-250 times more accurate than claimed uncertainties in theoretical computations for these systems. The data and methodology are useful for a wide range of applications, including major synchrotron and laboratory techniques relating to fine structure, near-edge analysis and standard crystallography. Experiments are sensitive to theoretical and computational issues, including correlation between convergence of electronic and atomic orbitals and wavefunctions. Hence, particularly in relation to the popular techniques of XAFS and XANES (X-ray absorption near-edge structure), this development calls for strong theoretical involvement but has great applications in solid state structural determination, catalysis and enzyme environments, active centres of biomolecules and organometallics, phase changes and fluorescence investigations and others. We discuss key features of the X-ray extended range technique (XERT) and illustrate applications.
Chantler, C. T.
Design considerations for a combined synchrotron-light source and heavy-ion storage ring Atomic Physics Facility
An Atomic Physics Facility (APF) based on the combination of photons produced by a synchrotron light source with heavy ions in a storage ring will open the way to the study of ionic states of almost all elements. The design considerations for such a facility are discussed in terms of the use of synchrotron radiation for photoexcitation and ionization experiments. Design considerations for an APF are given in terms of the accelerator facilities presently available at BNL which include the National Synchrotron Light Source and Tandem Van de Graaff Laboratory. The results show that the concept is valid and therefore that implementation would result in entirely new capabilities for the study of multiply-ionized atoms.
Jones, K.W.; Johnson, B.M.; Meron, M.; Lee, Y.Y.; Thieberger, P.; Thomlinson, W.C.
Industrial metrology as applied to large physics experiments
A physics experiment is a large complex 3-D object (typ. 1200 m{sup 3}, 35000 tonnes), with sub-millimetric alignment requirements. Two generic survey alignment tasks can be identified; first, an iterative positioning of the apparatus subsystems in space and, second, a quantification of as-built parameters. The most convenient measurement technique is industrial triangulation but the complexity of the measured object and measurement environment constraints frequently requires a more sophisticated approach. To enlarge the ``survey alignment toolbox`` measurement techniques commonly associated with other disciplines such as geodesy, applied geodesy for accelerator alignment, and mechanical engineering are also used. Disparate observables require a heavy reliance on least squares programs for campaign pre-analysis and calculation. This paper will offer an introduction to the alignment of physics experiments and will identify trends for the next generation of SSC experiments.
Veal, D.
Do general physics textbooks discuss scientists� ideas about atomic structure? A case in Korea
NASA Astrophysics Data System (ADS)
Research in science education has recognized the importance of teaching atomic structure within a history and philosophy of science perspective. The objective of this study is to evaluate general physics textbooks published in Korea based on the eight criteria developed in previous research. The result of this study shows that Korean general physics textbooks often lack detail about the history and philosophy of science. This result is quite similar to those published for the USA. Furthermore, chemistry textbooks published in the USA, Turkey and Venezuela are quite similar to the physics textbooks. This is a cause for concern as textbooks present theories as facts and ignore the historical reconstructions based on the development of scientific theories that frequently involve controversies and conflicts among scientists. The inclusion of historical reconstructions of ideas about atomic structure can provide students with a better appreciation of the dynamics of scientific progress.
Niaz, Mansoor; Kwon, Sangwoon; Kim, Nahyun; Lee, Gyoungho
Minimum Detection Efficiency for a Loophole-Free Atom-Photon Bell Experiment
In Bell experiments, one problem is to achieve high enough photodetection to ensure that there is no possibility of describing the results via a local hidden-variable model. Using the Clauser-Horne inequality and a two-photon nonmaximally entangled state, a photodetection efficiency higher than 0.67 is necessary. Here we discuss atom-photon Bell experiments. We show that, assuming perfect detection efficiency of the atom, it is possible to perform a loophole-free atom-photon Bell experiment whenever the photodetection efficiency exceeds 0.50.
Cabello, Adan; Larsson, Jan-Aake [Departamento de Fisica Aplicada II, Universidad de Sevilla, E-41012 Sevilla (Spain); Matematiska Institutionen, Linkoepings Universitet, SE-581 83 Linkoeping (Sweden)
Review: Experiments in Fundamental Physics Scheduled and in Development for the ISS
NASA Astrophysics Data System (ADS)
This is a review of those experiments in the area of Fundamental Physics that are either approved by ESA and NASA, or are currently under development, which are to be performed in the microgravity environment of the International Space Station. These experiments cover the physics of liquid Helium (SUE, BEST, MISTE, DYNAMX, and EXACT), ultrastable atomic clocks (PHARAO, PARCS, RACE), ultrastable microwave resonators (SUMO), and particle detectors (AMS and EUSO). The scientific goals are to study more precisely the universality properties of liquid Helium under microgravity conditions, to establish better time standards and to test the universality of the gravitational red shift, to make more precise tests of the constancy of the speed of light, and to measure the particle content in space directly without disturbances from the Earth's inner atmosphere.
L�mmerzahl, C.; Ahlers, G.; Ashby, N.; Barmatz, M.; Biermann, P. L.; Dittus, H.; Dohm, V.; Duncan, R.; Gibble, K.; Lipa, J.; Lockerbie, N.; Mulders, N.; Salomon, C.
Simulations of Ground and Space-Based Oxygen Atom Experiments
NASA Technical Reports Server (NTRS)
Fast, pulsed atomic oxygen sources are a key tool in ground-based investigations of spacecraft contamination and surface erosion effects. These technically challenging ground-based studies provide a before and after picture of materials under low-earth-orbit (LEO) conditions. It would be of great interest to track in real time the pulsed flux from the source to the surface sample target and beyond in order to characterize the population of atoms and molecules that actually impact the surface and those that make it downstream to any coincident detectors. We have performed simulations in order to provide such detailed descriptions of these ground-based measurements and to provide an assessment of their correspondence to the actual LEO environment. Where possible we also make comparisons to measured fluxes and erosion yields. To perform the calculations we use a detailed description of a measurement beam and surface geometry based on the W, pulsed apparatus at Montana State University. In this system, a short pulse (on the order of 10 microseconds) of an O/O2 beam impacts a flat sample about 40 cm downstream and slightly displaced &om the beam s central axis. Past this target, at the end of the beam axis is a quadrupole mass spectrometer that measures the relative in situ flux of 0102 to give an overall normalized erosion yield. In our simulations we use the Direct Simulation Monte Carlo (DSMC) method, and track individual atoms within the atomic oxygen pulse. DSMC techniques are typically used to model rarefied (few collision) gas-flows which occur at altitudes above approximately 110 kilometers. These techniques are well suited for the conditions here, and multi-collision effects that can only be treated by this or a similar technique are included. This simulation includes collisions with the surface and among gas atoms that have scattered from the surface. The simulation also includes descriptions of the velocity spread and spatial profiles of the O/O2 beam obtained from separate measurements. These computations use basic engineering models for the gas-gas and gas-surface scattering and focus on the influence of multi-collision effects. These simulations characterize many important quantities of interest including the actual flux of atoms that reach the surface, the energy distribution of this flux, as well as the direction of the velocity of the flux that strikes the surface. These quantities are important in characterizing the conditions which give rise to measured surface erosion. The calculations also yield time- snapshots of the pulse as it impacts and flows around the surface. These snapshots reveal the local environment of gas near the surface for the duration of the pulse. We are also able to compute the flux of molecules that travel downstream and reach the spectrometer, and we characterize their velocity distribution. The number of atoms that reach the spectrometer can in fact be influenced by the presence of the surface due to gas-gas collisions from atoms scattered h m the surface, and it will generally be less than that with the surface absent. This amounts to an overall normalization factor in computing erosion yields. We discuss these quantities and their relationship to the gas-surf$ce interaction parameters. We have also performed similar calculations corresponding to conditions (number densities, temperatures, and velocities) of low-earth orbit. The steady-state nature and lower overall flux of the actual space environment give rise to differences in the nature of the gas-impacts on the surface from those of the ground-based measurements using a pulsed source.
Minton, T. K.; Cline, J. A.; Braunstein, M.
Advanced Experiments in Nuclear Science, Volume I: Advanced Nuclear Physics and Chemistry Experiments.
ERIC Educational Resources Information Center
The experiments in this manual represent state-of-the-art techniques which should be within the budgetary constraints of a college physics or chemistry department. There are fourteen experiments divided into five modules. The modules are on X-ray fluorescence, charged particle detection, neutron activation analysis, X-ray attenuation, and�
Duggan, Jerome L.; And Others
Physical aging by periodic creep and interrupted creep experiments
NASA Astrophysics Data System (ADS)
A newly developed ``interrupted creep'' experiment has been used to study the physical aging of a low molecular weight polystyrene, Tg~69 �C. The results of the new experiment are compared to those obtained from traditional ``periodic creep'' experiments. The interrupted creep experiment provides information about the viscosity, the recoverable creep compliance and the steady-state compliance, Js, during aging. Low molecular weight polystyrene was chosen because it exhibits a steady-state compliance that is a strong function of temperature. Aging was conducted at three temperatures, 68.2, 65.7 and 61.0 �C, using both down-jump and up-jump experiments. The behavior observed in the new experiments mirrors the behavior observed in the traditional experiments. In addition, the new experiments allow the first ever determination of how Js evolves during aging. The change of Js with aging time was calculated using the relationship between the shift factors, obtained from the recoverable creep compliance data, and the average relaxation times, obtained from the viscosity. The advantage of the new experiment is that it provides both the short-time recoverable creep compliance information and the long-time viscous flow. By combining these contributions to the creep compliance in a simple additive fashion, one can obtain a more complete picture of how the material is behaving during aging.
Bernatz, Kevin M.; Giri, Lily; Simon, Sindee L.; Plazek, Donald J.
Symmetry and aesthetics in introductory physics: An experiment in interdisciplinary physics and fine arts education
NASA Astrophysics Data System (ADS)
In a recent editorial in Physics Today (July, 2006, p. 10) the ability of physicists to "imagine new realities" was correlated with what have been traditionally considered non-scientific qualities of imagination and creativity, which are usually associated with fine arts. In view of the current developments in physics of the 21st Century, including the searches for cosmic dark energy and evidence from the Large Hadron Collider which, it is hoped, will verify or refute the proposals of String Theory, the importance of developing creativity and imagination through education is gaining recognition. Two questions are addressed by this study: First, How can we bring the sense of aesthetics and creativity, which are important in the practice of physics, into the teaching and learning of physics at the introductory college level, without sacrificing the mathematical rigor which is necessary for proper understanding of physics? Second, How can we provide access to physics for a diverse population of students which includes physics majors, arts majors, and future teachers? An interdisciplinary curriculum which begins with teaching math as a language of nature, and utilizes arts to help visualize the connections between mathematics and the physical universe, may provide answers to these questions. In this dissertation I describe in detail the case study of the eleven students - seven physics majors and four arts majors - who participated in an experimental course, Symmetry and Aesthetics in Introductory Physics, in Winter Quarter, 2007, at UCSB's College of Creative Studies. The very positive results of this experiment suggest that this model deserves further testing, and could provide an entry into the study of physics for physics majors, liberal arts majors, future teachers, and as a foundation for media arts and technology programs.
van der Veen, Janet Krause
Atomic bombs and the long-run effect on trust: Experiences in Hiroshima and Nagasaki
Hiroshima and Nagasaki in Japan are the only cities in the world that have experienced an atomic bomb attack. This paper explores how this devastating experience affected victims� tendency to trust others. Individual-level data were used to examine the long-term influence of experiencing an atomic bomb on individuals� trust. After controlling for individual characteristics, I obtained the following key findings.
Eiji Yamamura
Colour polymeric paints research under atomic oxygen in flight and ground-based experiments
NASA Astrophysics Data System (ADS)
Three types of colour coatings were tested to atomic oxygen resistance on ground-based and in-flight experiments. The epoxy enamels colouring change and significant mass losses are observed. The effect of atomic oxygen on silicone enamels almost does not change their colouring and mass. Protection of the epoxy enamels by a layer of silicone varnish increases paints resistance.
Chernik, V. N.; Naumov, S. F.; Sokolova, S. P.; Gerasimova, T. I.; Kurilyonok, A. O.; Poruchikova, Ju. V.; Novikova, V. A.
An atom optics experiment to investigate faster-than-light tunneling
We describe a series of atom optics experiments underway at Toronto for investigating tunnelling interaction times of various sorts. We begin by discussing some outstanding issues and confusions related to the question of whether or not superluminal tunnelling can be construed as true faster-than-light signal propagation, a question which we answer in the negative. We then argue that atom optics
A. M. Steinberg; S. Myrskog; H. S. Moon; H. A. Kim; Jalani Fox; J. B. Kim
Time-of-Flight Experiments in Molecular Motion and Electron-Atom Collision Kinematics
ERIC Educational Resources Information Center
Describes a set of experiments for an undergraduate laboratory which demonstrates the relationship between velocity, mass, and temperature in a gas. The experimental method involves time-of-flight measurements on atoms excited to metastable states by electron impact. Effects resulting from recoil in the electron-atom collision can also be�
Donnelly, Denis P.; And Others
Cold Atom Optics on Ground and in Space
Microgravity is the ultimate laboratory environment for experiments in fundamental physics based on cold atoms. The talk will give a survey of recent activities on atomic quantum sensors and atom lasers. Inertial atomic quantum sensors are a promising and complementary technique for experiments in fundamental physics. Pioneering experiments at Yale [1,2] and Stanford [3] displayed recently the fascinating potential of
E. M. Rasel
Photoemission from solids: the transition from solid-state to atomic physics
As the photon energy is increased, photoemission from solids undergoes a slow transition from solid-state to atomic behavior. However, throughout the energy range h..nu.. = 10 to 1000 eV or higher both types of phenomena are present. Thus angle-resolved photoemission can only be understood quantitatively if each experimenter recognizes the presence of band-structure, photoelectron diffraction, and photoelectron asymmetry effects. The quest for this understanding will build some interesting bridges between solid-state and atomic physics and should also yield important new insights about the phenomena associated with photoemission.
Shirley, D.A.
20 CFR 220.127 - When the only work experience is arduous unskilled physical labor.
Code of Federal Regulations, 2011 CFR
...work experience is arduous unskilled physical labor. 220.127 Section 220...work experience is arduous unskilled physical labor. (a) Arduous work. Arduous work is primarily physical work requiring a high level of...
20 CFR 220.127 - When the only work experience is arduous unskilled physical labor.
Code of Federal Regulations, 2010 CFR
...work experience is arduous unskilled physical labor. 220.127 Section 220...work experience is arduous unskilled physical labor. (a) Arduous work. Arduous work is primarily physical work requiring a high level of...
20 CFR 220.127 - When the only work experience is arduous unskilled physical labor.
Code of Federal Regulations, 2012 CFR
...work experience is arduous unskilled physical labor. 220.127 Section 220...work experience is arduous unskilled physical labor. (a) Arduous work. Arduous work is primarily physical work requiring a high level of...
Physics Results from the Antiproton Experiment (APEX) at Fermilab
Is Antimatter stable? The APEX experiment searches for the decay of antiprotons at the Fermilab Antiproton Accumulator. Observation of antiproton decay would indicate a violation of the CPT theorem, which is one of the most fundamental theorems of modern physics. The best laboratory limits on antiproton decay come from the APEX experiment which achieved a sensitivity to antiproton lifetimes up to of order 700,000 years for the most sensitive decay modes. Antiproton lifetimes in this range could arise from CPT violation at the Planck scale.[copied from http://www-apex.fnal.gov/] This website presents published results from the APEX Test Experiment (T861) and from the E868 Experiment. Limits were placed on six antiproton decay modes with a muon in the final state and on seven antiproton decay modes with an electron in the final state. See also the summary table and plot and the APEX picture gallery.
APEX Collaboration
Simulations of Ground and Space-Based Oxygen Atom Experiments
NASA Technical Reports Server (NTRS)
A low-earth orbit (LEO) materials erosion scenario and the ground-based experiment designed to simulate it are compared using the direct-simulation Monte Carlo (DSMC) method. The DSMC model provides a detailed description of the interactions between the hyperthermal gas flow and a normally oriented flat plate for each case. We find that while the general characteristics of the LEO exposure are represented in the ground-based experiment, multi-collision effects can potentially alter the impact energy and directionality of the impinging molecules in the ground-based experiment. Multi-collision phenomena also affect downstream flux measurements.
Finchum, A. (Technical Monitor); Cline, J. A.; Minton, T. K.; Braunstein, M.
Understanding the learning assistant experience with physics identity
NASA Astrophysics Data System (ADS)
Learning Assistants (LAs) have been shown to have better conceptual understanding and more favorable beliefs about science than non-LAs, and are more likely to choose a career in K-12 science teaching [1]. We propose that connections between elements of identity, persistence, and participation in an LA program can be explained using the concept of the community of practice and its intimate relationship to identity [2]. In separate work, Hazari et al. found that physics identity was highly correlated to expressed career plans in physics [3]. We hypothesize that a thriving LA program has many features of a well-functioning community of practice and contributes to all four elements of physics identity: personal interest, student performance, competence, and recognition by others. We explore how this analysis of the LA experience might shape decisions and influence outcomes of adoption and adaptations of the LA model.
Close, Eleanor W.; Close, Hunter G.; Donnelly, David
Understanding the learning assistant experience with physics identity
NSDL National Science Digital Library
Learning Assistants (LAs) have been shown to have better conceptual understanding and more favorable beliefs about science than non-LAs, and are more likely to choose a career in K-12 science teaching [1]. We propose that connections between elements of identity, persistence, and participation in an LA program can be explained using the concept of the community of practice and its intimate relationship to identity [2]. In separate work, Hazari et al. found that physics identity was highly correlated to expressed career plans in physics [3]. We hypothesize that a thriving LA program has many features of a well-functioning community of practice and contributes to all four elements of physics identity: personal interest, student performance, competence, and recognition by others. We explore how this analysis of the LA experience might shape decisions and influence outcomes of adoption and adaptations of the LA model.
Close, Eleanor W.; Close, Hunter G.; Donnelly, David
Tevatron End-of-Run Beam Physics Experiments
Before the Tevatron Collider Run II ended in September of 2011, a number of specialized beam study periods were dedicated to the experiments on various accelerator physics concepts and effects during the last year of the machine operation. The study topics included collimation with bent crystals and hollow electron beams, diffusion measurements and various aspects of beam-beam interactions. In this report we concentrate on the subject of beam-beam interactions, summarizing the results of beam experiments. The covered topics include offset collisions, coherent beam stability, effect of the bunch-length-to-beta-function ratio, and operation of AC dipole with colliding beams.
Valishev, A.; /Fermilab; Gu, X.; Miyamoto, R.; White, S.; /BNL; Schmidt, F.; /CERN; Qiang, J.; /LBNL
Alpha Particle Physics Experiments in the Tokamak Fusion Test Reactor
Alpha particle physics experiments were done on the Tokamak Fusion Test Reactor (TFTR) during its deuterium-tritium (DT) run from 1993-1997. These experiments utilized several new alpha particle diagnostics and hundreds of DT discharges to characterize the alpha particle confinement and wave-particle interactions. In general, the results from the alpha particle diagnostics agreed with the classical single-particle confinement model in magnetohydrodynamic (MHD) quiescent discharges. Also, the observed alpha particle interactions with sawteeth, toroidal Alfv�n eigenmodes (TAE), and ion cyclotron resonant frequency (ICRF) waves were roughly consistent with theoretical modeling. This paper reviews what was learned and identifies what remains to be understood.
Budny, R.V.; Darrow, D.S.; Medley, S.S.; Nazikian, R.; Zweben, S.J.; et al.
Experience, gender, and performance: Connecting high school physics experience and gender differences to introductory college physics performance
NASA Astrophysics Data System (ADS)
Current science educational practice is coming under heavy criticism based on the dismaying results of the Third International Mathematics and Science Study of 1998, the latest in a series of large scale surveys; and from research showing the appallingly low representation of females in science-related fields. These critical evaluations serve to draw attention to science literacy in general and lack of persistence among females in particular, two issues that relate closely to the "preparation for future study" goal held by many high school science teachers. In other words, these teachers often seek to promote future success and to prevent future failure in their students' academic careers. This thesis studies the connection between the teaching practices recommended by reformers and researchers for high school teachers, and their students' subsequent college physics performance. The teaching practices studied were: laboratory experiences, class discussion experiences, content coverage, and reliance on textbooks. This study analyzed a survey of 1500 students from 16 different lecture-format college physics courses at 14 different universities. Using hierarchical linear modeling, this study accounted for course-level variables (Calculus-based/Non-calculus course type, professor's gender, and university selectivity). This study controlled for the student's parents education, high school science/mathematics achievement, high school calculus background, and racial background. In addition, the interactions between gender and both pedagogical/curricular and course-level variables were analyzed. The results indicated that teaching fewer topics in greater depth in high school physics appeared to be helpful to college physics students. An interaction between college course type and content coverage showed that students in Calculus-based physics reaped even greater benefits from a depth-oriented curriculum. Also students with fewer labs per month in high school physics appeared to perform better in college physics than did students with many more labs per month. The only significant interaction was between gender and Calculus-based/Non-calculus college course type. Females appeared to do better on average than their males counterparts in Non-calculus physics, but this trend is clearly reversed for Calculus-based physics. This is a disturbing result for educators who have worked to promote persistence among women in engineering and science research. Recommendations are included for high school physics teachers, students and their parents, and college physics instructors.
Tai, Robert H.
Conductive education for physically handicapped children: parental expectations and experience.
Conductive education, an educational approach devised by Andras Pet� in Hungary after the second world war, has attracted considerable media attention. Eight Northern Ireland families who recently had treatment for their disabled child at the Pet� Institute in Budapest were identified. Six families returned postal questionnaires designed to look at parental experience of conductive education. An improvement in existing local services, as opposed to the wholesale introduction of this facility was the commonest parental hope for future provision for physically handicapped children.
Hill, A. E.
A simple digital delay for nuclear physics experiments
NASA Astrophysics Data System (ADS)
A simple high precision digital delay for nuclear physics experiments was developed using fast ECL electronics. The circuit uses an oscillator synchronized with the signal to be delayed and a presettable counter. It is capable of delaying a negative NIM signal by 2 �s with a precision better than 50 ps. The circuit was developed for use in slow-fast coincidence units for Perturbed Angular Correlation spectrometers but it is not limited to this application.
Marques, J. G.; Cruz, C.
Can There BE Physics Without Experiments? Challenges and Pitfalls
NASA Astrophysics Data System (ADS)
Physicists investigating space, time and matter at the Planck scale will probably have to work with much less guidance from experimental input than has ever happened before in the history of Physics. This may imply that we should insist on much higher demands of logical and mathematical rigour than before. Working with long chains of arguments linking theories to experiment, we must be able to rely on logical precision when and where experimental checks cannot be provided.
't Hooft, Gerard
Experiments with Ultracold Quantum-degenerate Fermionic Lithium Atoms
NASA Technical Reports Server (NTRS)
Experimental methods of laser and evaporative cooling, used in the production of atomic Bose-Einstein condensates have recently been extended to realize quantum degeneracy in trapped Fermi gases. Fermi gases are a new rich system to explore the implications of Pauli exclusion on scattering properties of the system, and ultimately fermionic superfluidity. We have produced a new macroscopic quantum system, in which a degenerate Li-6 Fermi gas coexists with a large and stable Na-23 BEC. This was accomplished using inter-species sympathetic cooling of fermionic 6Li in a thermal bath of bosonic Na-23. We have achieved high numbers of both fermions (less than 10(exp 5) and bosons (less than 10(exp 6), and Li-6 quantum degeneracy corresponding to one half of the Fermi temperature. This is the first time that a Fermi sea was produced with a condensate as a "refrigerator".
Ketterle, Wolfgang
Construction and characterization of external cavity diode lasers for atomic physics.
Since their development in the late 1980s, cheap, reliable external cavity diode lasers (ECDLs) have replaced complex and expensive traditional dye and Titanium Sapphire lasers as the workhorse laser of atomic physics labs. Their versatility and prolific use throughout atomic physics in applications such as absorption spectroscopy and laser cooling makes it imperative for incoming students to gain a firm practical understanding of these lasers. This publication builds upon the seminal work by Wieman, updating components, and providing a video tutorial. The setup, frequency locking and performance characterization of an ECDL will be described. Discussion of component selection and proper mounting of both diodes and gratings, the factors affecting mode selection within the cavity, proper alignment for optimal external feedback, optics setup for coarse and fine frequency sensitive measurements, a brief overview of laser locking techniques, and laser linewidth measurements are included. PMID:24796259
Hardman, Kyle S; Bennetts, Shayne; Debs, John E; Kuhn, Carlos C N; McDonald, Gordon D; Robins, Nick
Experiences of Psychological and Physical Aggression in Adolescent Romantic Relationships: Links to Psychological Distress
ERIC Educational Resources Information Center
Objective: This research examined links between adolescents' experiences of psychological and physical relationship aggression and their psychological distress. Experiences of psychological and physical aggression were expected to correlate positively with symptoms of psychological distress, but experiences of psychological aggression were�
Jouriles, Ernest N.; Garrido, Edward; Rosenfield, David; McDonald, Renee
Results of {open_quotes}Heisenberg Microscope{close_quotes} decoherence atom interferometry experiments
We present results of atom interferometry experiments in which spatial matter - wave interference is revealed by its selective destruction. A thermal potassium beam is transmitted through a velocity selective atom interferometer and detected. The interferometer is a sequence of three diffraction gratings. Interference fringes forming a Moire pattern with the third grating determine the transmission. The thermal beam produces a velocity average over different fringe Fourier components, each resonant in the interferometer at a different atomic velocity. AC modulated laser light passes through the interferometer, near the middle grating. Since imaging of the fluorescent light could be used to determine which slit an atom passes, the contribution to the fringe pattern by atoms at the laser`s Doppler shifted wavelength is removed. That component is thus AC modulated and detected. This {open_quotes}atom interference filter{close_quotes} resolves the K{sup 39} HFS.
Clauser, J.F.; Li, S.; Reinsch, M.W. [Univ. of California, Berkeley, CA (United States)
Autonomy and the Student Experience in Introductory Physics
NASA Astrophysics Data System (ADS)
The role of autonomy in the student experience in a large-enrollment undergraduate introductory physics course was studied from a Self-Determination Theory perspective with two studies. Study I, a correlational study, investigated whether certain aspects of the student experience correlated with how autonomy supportive (vs. controlling) students perceived their instructors to be. An autonomy supportive instructor acknowledges students' perspectives, feelings, and perceptions and provides students with information and opportunities for choice, while minimizing external pressures. It was found that the degree to which students perceived their instructors as autonomy supportive was positively correlated with student interest and enjoyment in learning physics (beta=0.31***) and negatively correlated with student anxiety about taking physics (beta=-0.23**). It was also positively correlated with how autonomous (vs. controlled) students' reasons for studying physics became over the duration of the course (i.e., studying physics more because they wanted to vs. had to; beta=0.24***). This change in autonomous reasons for studying physics was in turn positively correlated with student performance in the course (beta=0.17*). Additionally, the degree to which students perceived their instructors as autonomy supportive was directly correlated with performance for those students entering the course with relatively autonomous reasons for studying physics (beta=0.25**). In summary, students who perceived their instructors as more autonomy supportive tended to have a more favorable experience in the course. If greater autonomy support was in fact the cause of a more favorable student experience, as suggested by Self-determination Theory and experimental studies in other contexts, these results would have implications for instruction and instructor professional development in similar contexts. I discuss these implications. Study II, an experimental study, investigated the effect, on the student experience, of the number of opportunities for choice built into the course format. This was done by comparing two sets of classes. In one set of classes, students spent each class period working through a required series of activities. In the other set of classes, with additional choice, students were free to choose what to work on during nearly half of each class. It was found that the effect of additional choice on student interest and enjoyment in learning physics was significantly different for men vs. women, with a Cohen's d of 0.62 (0.16-1.08; 95% CI). Men became somewhat more interested with additional choice and women became less interested. This gender difference in interest and enjoyment as a result of additional choice could not be accounted for by differences in performance. It was also found that only in classes with additional choice did performance in the course correlate with the degree to which students reasons for studying physics became more autonomous during the quarter (beta=0.30*). I discuss the implications that these effects of additional choice have for instruction and course design in similar contexts.
Hall, Nicholas Ron
Physical basis of coastal productivity: The SEEP and MASAR experiments
NASA Astrophysics Data System (ADS)
Two major cooperative experiments, code-named Shelf Edge Exchange Processes (SEEP) I and II, were carried out on the northeast U.S. continental shelf and slope by an interdisciplinary group of scientists in the past decade. The work, supported by the Department of Energy, Office of Health and Environmental Research, had the broad aim of determining whether or to what extent energy-related human activities interfere with the high biological productivity of coastal waters. Much of SEEP I work was reported in a dedicated issue of Continental Shelf Research, including a summary article on the experiment as a whole [Walsh et al., 1988[. A parallel experiment, supported by the Minerals Management Service and code-named Mid Atlantic Slope and Rise (MASAR), had the objective of exploring physical processes over the continental slope and rise, including especially currents in the upper part of the water column. A good deal of MASAR work was also reported in the SEEP issue just mentioned, mainly in an article by Csanady and Hamilton (1988). There have been other papers and publications on these experiments, and more are forthcoming. While many questions remain, our horizons have broadened considerably after a decade of work on this problem, as if our aeroplane had just emerged from clouds to expose an interesting landscape. In this article I shall try to describe the physical (-oceanographic) features of that landscape, not in the chronological order in which we have espied them, but as the logic of the subject dictates.
Csanady, G. T.
FROM THE HISTORY OF PHYSICS: The development of the first Soviet atomic bomb
NASA Astrophysics Data System (ADS)
In the late 1930s and early 1940s, two remarkable physical phenomena � the fission of heavy nuclei and the chain fission reaction � were discovered, implying that a new powerful source of energy (nuclear fission energy) might become a practical possibility for mankind. At that time, however, the political situation in the world made the development of the atomic bomb the main objective of nuclear energy research in the countries involved. The first atomic bombs, notoriously used in the war against Japan, were produced by the United States of America only six and a half years after the discovery of fission. Four years later, the first Soviet atomic bomb was tested. This was a major step toward the establishment of nuclear parity which led to stability and global peace and thus greatly influenced the destiny of human kind. Based on documentary materials covering the period from 1939 to 1949, this paper traces the origin and evolution of the physical ideas behind the first Soviet atomic bomb and discusses the most important events associated with the project.
Goncharov, German A.; Ryabev, Lev D.
A distributed atomic physics database and modeling system for plasma spectroscopy
We are undertaking to develop a set of computational capabilities which will facilitate the access, manipulation, and understanding of atomic data in calculations of x-ray spectral modeling. In this present limited description we will emphasize the objectives for this work, the design philosophy, and aspects of the atomic database, as a more complete description of this work is available. The project is referred to as the Plasma Spectroscopy Initiative; the computing environment is called PSI, or the ``PSI shell`` since the primary interface resembles a UNIX shell window. The working group consists of researchers in the fields of x-ray plasma spectroscopy, atomic physics, plasma diagnostics, line shape theory, astrophysics, and computer science. To date, our focus has been to develop the software foundations, including the atomic physics database, and to apply the existing capabilities to a range of working problems. These problems have been chosen in part to exercise the overall design and implementation of the shell. For successful implementation the final design must have great flexibility since our goal is not simply to satisfy our interests but to vide a tool of general use to the community.
Nash, J.K.; Liedahl, D.; Chen, M.H.; Iglesias, C.A.; Lee, R.W. [Lawrence Livermore National Lab., CA (United States); Salter, J.M. [South Gosforth Computer Systems, Newcastle upon Tyne (United Kingdom)
Spectroscopy of antiprotonic helium atoms and its contribution to the fundamental physical constants
Antiprotonic helium atom, a metastable neutral system consisting of an antiproton, an electron and a helium nucleus, was serendipitously discovered, and has been studied at CERN�s antiproton decelerator facility. Its transition frequencies have recently been measured to nine digits of precision by laser spectroscopy. By comparing these experimental results with three-body QED calculations, the antiproton-to-electron massratio was determined as 1836.152674(5). This result contributed to the CODATA recommended values of the fundamental physical constants.
Hayano, Ryugo S.
Introductory Physics Experiments Using the Wii Balance Board
NASA Astrophysics Data System (ADS)
The Wii, a video game console by Nintendo, utilizes several different controllers, such as the Wii remote (Wiimote) and the balance board, for game-playing. The balance board was introduced in early 2008. It contains four strain gauges and has Bluetooth connectivity at a relatively low price. Thanks to available open source code, such as GlovePie, any PC with Bluetooth capability can detect the information sent out by the balance board. Based on the ease with which the forces measured by each strain gauge can be obtained, we have designed several experiments for introductory physics courses that make use of this device. We present experiments to measure the forces generated when students lift their arms with and without added weights, distribution of forces on an extended object when weights are repositioned, and other normal forces cases. The results of our experiments are compared with those predicted by Newtonian mechanics. )
Starr, Julian; Sobczak, Robert; Iqbal, Zohaib; Ochoa, Romulo
Source physics experiments at the Nevada Test Site.
The U. S. capability to monitor foreign underground nuclear test activities relies heavily on measurement of explosion phenomena, including characteristic seismic, infrasound, radionuclide, and acoustic signals. Despite recent advances in each of these fields, empirical, rather than physics-based, approaches are used to predict and explain observations. Seismologists rely on prior knowledge of the variations of teleseismic and regional seismic parameters such as p- and s-wave arrivals from simple one-dimensional models for the teleseismic case to somewhat more complicated enhanced two-dimensional models for the regional case. Likewise, radionuclide experts rely on empirical results from a handful of limited experiments to determine the radiological source terms present at the surface after an underground test. To make the next step in the advancement of the science of monitoring we need to transform these fields to enable predictive, physics-based modeling and analysis. The Nevada Test Site Source Physics Experiments (N-SPE) provide a unique opportunity to gather precise data from well-designed experiments to improve physics-based modeling capability. In the seismic experiments, data collection will include time domain reflectometry to measure explosive performance and yield, free-field accelerometers, extensive seismic arrays, and infrasound and acoustic measurements. The improved modeling capability that we will develop using this data should enable important advances in our ability to monitor worldwide for nuclear testing. The first of a series of source physics experiments will be conducted in the granite of Climax Stock at the NTS, near the locations of the HARD HAT and PILE DRIVER nuclear tests. This site not only provides a fairly homogeneous and well-documented geology, but also an opportunity to improve our understanding of how fractures, joints, and faults affect seismic wave generation and propagation. The Climax Stock experiments will consist of a 220 lb (TNT equivalent) calibration shot and a 2200 lb (TNT equivalent) over-buried shot conducted in the same emplacement hole. An identical 2200 lb shot at the same location will follow to investigate the effects of pre-conditioning. These experiments also provide an opportunity to advance capabilities for near-field monitoring, and on-site inspections (OSIs) of suspected testing sites. In particular, geologic, physical, and cultural signatures of underground testing can be evaluated using the N-SPE activities as case studies. Furthermore, experiments to measure the migration of radioactive noble gases to the surface from underground explosions will enable development of higher fidelity radiological source term models that can predict migration through a variety of geologic conditions. Because the detection of short-lived radionuclides is essential to determining if an explosion was nuclear or conventional, a better understanding of the gaseous and particulate radionuclide source terms that reach the surface from underground testing is critical to development of OSI capability.
Lee, Ping (Nuclear Security Technologies, Inc.); Snelson, Catherine (Nuclear Security Technologies, Inc.); Abbott, Robert; Coblentz, David D. (Los Alamos National Laboratory); Corbell, Robert; Bowyer, Theodore W. (Pacific Northwest National Laboratory); Sussman, Aviva J. (Los Alamos National Laboratory); Carrigan, Charles R. (Lawrence Livermore National Laboratory); Bradley, Christopher R. (Los Alamos National Laboratory); Patton, Howard J. (Los Alamos National Laboratory); Seifert, Carolyn E. (Pacific Northwest National Laboratory); Sweeney, Jerry J. (Lawrence Livermore National Laboratory); Brunish, Wendee M. (Los Alamos National Laboratory); Hawkins, Ward L. (Los Alamos National Laboratory); Antoun,Tarabay H. (Lawrence Livermore National Laboratory); Wohletz, Kenneth H. (Los Alamos National Laboratory); Zucca, John Jay (Lawrence Livermore National Laboratory)
Experience Using Formal Methods in High Energy Physics
NASA Astrophysics Data System (ADS)
We report our experience using the formal method VDM++ in high energy physics real-time applications. VDM++ is an extension of the established formal method VDM to include object-oriented, concurrency and real-time features. VDM++ is supported by the VENUS tool-set, comprising an OMT graphical editor, VDM++ syntax and type checker, and a C++ code generator. Formal specification meta-languages allow formal data modeling, algorithm and system behavior specification at a highly abstract level. Once an abstract design has converged it is refined towards a particular implementation, with formal validation of each step if desired. We have applied VDM++ to the design of a fast track pattern recognition algorithm; the design of a global second- level trigger system for LHC experiments; the specification of simulated physics data; and the design of a data router hardware unit for a LHC second-level trigger. We are encouraged by the application of mathematics in an engineering discipline and conclude that formal methods have the potential to make a valuable contribution to the systems development process in high energy physics.
Balke, A. C.; Carter, J.; Haveman, J.
Negative Experiences in Physical Education and Sport: How Much Do They Affect Physical Activity Participation Later in Life?
ERIC Educational Resources Information Center
People's feelings toward physical activity are often influenced by memories of their childhood experiences in physical education and sport. Unfortunately, many adults remember negative experiences, which may affect their desire to maintain a physically active lifestyle. A survey that asked 293 students about recollections from their childhood�
Cardinal, Bradley J.; Yan, Zi; Cardinal, Marita K.
Experiences of physical activity during pregnancy in Danish nulliparous women with a physically active life before pregnancy. A qualitative study
BACKGROUND: National guidelines recommend that healthy pregnant women take 30 minutes or more of moderate exercise a day. Most women reduce the level of physical activity during pregnancy but only a few studies of women's experiences of physical activity during pregnancy exist. The aim of the present study was to elucidate experiences and views of leisure time physical activity during
Hanne K Hegaard; Hanne Kjaergaard; Peter P Damm; Kerstin Petersson; Anna-Karin Dykes
New physics and technology for spin-polarized alkali-metal atoms
NASA Astrophysics Data System (ADS)
In this theses, we present two important new physics phenomena of spin-polarized alkali-metal atoms as well as one new technology for miniature atomic clocks based on spin-polarized alkali-metal atoms. We report that the hyperfine resonance frequencies of ground-state 87Rb and 133Cs depend on the pressure of buffer gases Ar and Kr in a nonlinear way within some pressure range[1]. We also show that for buffer gases He and N2, no nonlinear dependence was observed. The experimental results suggest that the formation of van der Waals molecules in Ar or Kr (e.g. RbAr or CsKr) contribute to the nonlinear pressure dependence of the hyperfine resonance frequencies of Rb or Cs. We demonstrate that a simple function can be used to fit the experimental data and the fitting results provide important information about the poorly-known interaction coefficients between the alkali-metal atoms and the buffer-gas atoms. Next we present a novel phenomenon which was reported for the first time[2]. For alkali-metal atoms that are optically pumped with D1 circularly-polarized laser light, the microwave resonance signals will be reversed when the laser frequency is close to the transition from the lower hyperfine multiplet of the ground state to the excited state and when the laser intensity is sufficiently low. This counterintuitive phenomenon can be understood qualitatively with the help of a picture of spin-temperature distribution. Detailed density matrix calculation gave us results consistent with the experimental observation. Finally we demonstrate a new method to fill some alkali-metal vapor into a miniature vapor cell (with the volume of several mm3)[3]. This method uses the electrolysis of a specially-made borate glass which contains the target alkali-metal atoms. The electrolysis can be done because the mobility of the alkali-metal atoms in the borate glass is increased greatly at higher temperatures (e.g. 500�C) and in electric fields. With this method, we are able to fill a well-controlled amount of alkali-metal atoms into miniature vapor cells which are made with silicon and Pyrex glass by anodic bonding. This method has the potential to be scaled to mass production of such miniature vapor cells for miniature atomic clocks.
Gong, Fei
[Physically handicapped pupils at a regular school - experiences of the school experiment "Lichtenau" (author's transl)].
As an experiment in integration, the joint placement of physically handicapped and non-disabled pupils into the regular class settings of a school belonging to the Hessisch-Lichtenau experiment makes special social and educational measures necessary both at school and in the residential home. The main activities have to be directed towards scientific studies of existing problems and their practical solutions. The following article describes the problems arising from the integrational efforts and suggests possible solutions. PMID:153569
Jung, M; Steinke, T
A Reconfigurable Instrument System for Nuclear and Particle Physics Experiments
NASA Astrophysics Data System (ADS)
We developed a reconfigurable nuclear instrument system (RNIS) that could satisfy the requirements of diverse nuclear and particle physics experiments, and the inertial confinement fusion diagnostic. Benefiting from the reconfigurable hardware structure and digital pulse processing technology, RNIS shakes off the restrictions of cumbersome crates and miscellaneous modules. It retains all the advantages of conventional nuclear instruments and is more flexible and portable. RNIS is primarily composed of a field programmable hardware board and relevant PC software. Separate analog channels are designed to provide different functions, such as amplifiers, ADC, fast discriminators and Schmitt discriminators for diverse experimental purposes. The high-performance field programmable gate array could complete high-precision time interval measurement, histogram accumulation, counting, and coincidence anticoincidence measurement. To illustrate the prospects of RNIS, a series of applications to the experiments are described in this paper. The first, for which RNIS was originally developed, involves nuclear energy spectrum measurement with a scintillation detector and photomultiplier. The second experiment applies RNIS to a G-M tube counting experiment, and in the third, it is applied to a quantum communication experiment through reconfiguration.
Sang, Ziru; Li, Feng; Jiang, Xiao; Jin, Ge
A Physics Exploratory Experiment on Plasma Liner Formation
NASA Technical Reports Server (NTRS)
Momentum flux for imploding a target plasma in magnetized target fusion (MTF) may be delivered by an array of plasma guns launching plasma jets that would merge to form an imploding plasma shell (liner). In this paper, we examine what would be a worthwhile experiment to do in order to explore the dynamics of merging plasma jets to form a plasma liner as a first step in establishing an experimental database for plasma-jets driven magnetized target fusion (PJETS-MTF). Using past experience in fusion energy research as a model, we envisage a four-phase program to advance the art of PJETS-MTF to fusion breakeven Q is approximately 1). The experiment (PLX (Plasma Liner Physics Exploratory Experiment)) described in this paper serves as Phase I of this four-phase program. The logic underlying the selection of the experimental parameters is presented. The experiment consists of using twelve plasma guns arranged in a circle, launching plasma jets towards the center of a vacuum chamber. The velocity of the plasma jets chosen is 200 km/s, and each jet is to carry a mass of 0.2 mg - 0.4 mg. A candidate plasma accelerator for launching these jets consists of a coaxial plasma gun of the Marshall type.
Thio, Y. C. Francis; Knapp, Charles E.; Kirkpatrick, Ronald C.; Siemon, Richard E.; Turchi, Peter
QUANTUS: Implementing atom optical experiments in the Bremen drop tower
NASA Astrophysics Data System (ADS)
We report on the current status of the QUANTUS free fall BEC experiment at the ZARM drop tower in Bremen. After the first realization of a BEC in microgravity in 2007, we were able to observe conden-sates after an unprecedented time of free evolution. The extremely shallow traps possible in microgravity and resulting ultralow temperatures of a few nK allow for further studies ranging from coherence properties of condensates to inertial sensors based on matter waves. In our talk we will focus on technological challanges of the project and its roll in bringing matter wave optics into space. A drop tower experiment is considered a stepping stone towards the ISS or other platforms as it makes high demands on mechanical stability, power consumption and payload. After showing the feasibility of such a project we are now working on a second generation apparatus which leads the way to high precision measurements of gravitational forces and eventually a quantum test of Einstein's weak equivalence principle. These goals are worked on in close cooperation with QUEST and the projects PRIMUS and LASUS. The QUANTUS project is a collaboration of U Hamburg, U Ulm, HU Berlin, MPQ Munich, ZARM at U Bremen and LU Hannover. It is supported by the German Space Agency DLR with funds provided by the Federal Ministry of Economics and Technology (BMWi) under grant numbers 50WM0835 -50WM0839.
M�ntinga, Hauke; van Zoest, T.; Ahlers, H.; Seidel, S. T.; Herr, W.; Rudolph, J.; Gaaloul, N.; Singh, Y.; Schulze, T. A.; Rode, C.; Schkolnik, V.; Ertmer, W.; Rasel, E.; M�ntinga, H.; K�nemann, T.; Resch, A.; Herrmann, S.; L�mmerzahl, C.; Dittus, H.; Vogel, A.; Wenzlawski, A.; Sengstock, K.; Meyer, N.; Bongs, K.; Krutzik, M.; Lewoczko-Adamczyk, W.; Schiemangk, M.; Peters, A.; Eckart, M.; Kajari, E.; Arnold, S.; Nandi, G.; Walser, R.; Schleich, W. P.; Steinmetz, T.; H�nsch, T. W.; Reichel, J.
The International Reactor Physics Experiment Evaluation Project (IRPHEP)
Since the beginning of the Nuclear Power industry, numerous experiments concerned with nuclear energy and technology have been performed at different research laboratories, worldwide. These experiments required a large investment in terms of infrastructure, expertise, and cost; however, many were performed without a high degree of attention to archival of results for future use. The degree and quality of documentation varies greatly. There is an urgent need to preserve integral reactor physics experimental data, including measurement methods, techniques, and separate or special effects data for nuclear energy and technology applications and the knowledge and competence contained therein. If the data are compromised, it is unlikely that any of these experiments will be repeated again in the future. The International Reactor Physics Evaluation Project (IRPhEP) was initiated, as a pilot activity in 1999 by the by the Organization of Economic Cooperation and Development (OECD) Nuclear Energy Agency (NEA) Nuclear Science Committee (NSC). The project was endorsed as an official activity of the NSC in June of 2003. The purpose of the IRPhEP is to provide an extensively peer reviewed set of reactor physics related integral benchmark data that can be used by reactor designers and safety analysts to validate the analytical tools used to design next generation reactors and establish the safety basis for operation of these reactors. A short history of the IRPhEP is presented and its purposes are discussed in this paper. Accomplishments of the IRPhEP, including the first publication of the IRPhEP Handbook, are highlighted and the future of the project outlined.
J. Blair Briggs; Enrico Sartori; Lori Scott
Physics of Hard Spheres Experiment (PhaSE) or "Making Jello in Space"
NASA Technical Reports Server (NTRS)
The Physics of Hard Spheres Experiment (PHaSE) is a highly successful experiment that flew aboard two shuttle missions to study the transitions involved in the formation of jellolike colloidal crystals in a microgravity environment. A colloidal suspension, or colloid, consists of fine particles, often having complex interactions, suspended in a liquid. Paint, ink, and milk are examples of colloids found in everyday life. In low Earth orbit, the effective force of gravity is thousands of times less than at the Earth's surface. This provides researchers a way to conduct experiments that cannot be adequately performed in an Earth-gravity environment. In microgravity, colloidal particles freely interact without the complications of settling that occur in normal gravity on Earth. If the particle interactions within these colloidal suspensions could be predicted and accurately modeled, they could provide the key to understanding fundamental problems in condensed matter physics and could help make possible the development of wonderful new "designer" materials. Industries that make semiconductors, electro-optics, ceramics, and composites are just a few that may benefit from this knowledge. Atomic interactions determine the physical properties (e.g., weight, color, and hardness) of ordinary matter. PHaSE uses colloidal suspensions of microscopic solid plastic spheres to model the behavior of atomic interactions. When uniformly sized hard spheres suspended in a fluid reach a certain concentration (volume fraction), the particle-fluid mixture changes from a disordered fluid state, in which the spheres are randomly organized, to an ordered "crystalline" state, in which they are structured periodically. The thermal energy of the spheres causes them to form ordered arrays, analogous to crystals. Seven of the eight PHaSE samples ranged in volume fraction from 0.483 to 0.624 to cover the range of interest, while one sample, having a concentration of 0.019, was included for instrument calibration.
Ling, Jerri S.; Doherty, Michael P.
Multimicroprocessor system for high-energy physics experiment applications
NASA Astrophysics Data System (ADS)
An autonomous modular multicomputer system based on the INTEL 8080 for program development and for application to the high-energy physics experiment "RISK" is presented. The associated microcomputers (a three-processor configuration is realized) with uniform software systems can perform, in parallel, the interactively-controlled processing and monitoring of data accessible in the common memory block coupled to the processors via the direct shared bus. Data are acquired into the common memory buffer by the main processor, which is linked by the CAMAC interface with the experimental apparatus and optionally with a large-size computer. One microcomputer can be connected with the magnetic tape unit used for data recording.
P�ka, K.; Falkenberg, W.; Glasneck, C.-P.; Pflugbeil, W.
Physics basis and simulation of burning plasma physics for the fusion ignition research experiment (FIRE)
The FIRE design for a burning plasma experiment is described in terms of its physics basis and engineering features. Systems analysis indicates that the device has a wide operating space to accomplish its mission, both for the ELMy H-mode reference and the high bootstrap current\\/high-? advanced tokamak regimes. Simulations with 1.5D transport codes reported here both confirm and constrain the
C. E. Kessel; D. Meade; S. C. Jardin
Upper Secondary Students' Understanding of the Basic Physical Interactions in Analogous Atomic and Solar Systems
NASA Astrophysics Data System (ADS)
Comparing the atom to a `tiny solar system' is a common teaching analogy, and the extent to which learners saw the systems as analogous was investigated. English upper secondary students were asked parallel questions about the physical interactions between the components of a simple atomic system and a simple solar system to investigate how they understood the forces acting within the two systems. A sample of just over 100 across the 15-18 age range responded to a pencil-and-paper instrument that asked about four aspects of the two systems. It was found that for both systems, about four fifths of students expected forces to decrease with increasing distance; but that only a little over half expected there to be interactions between the minor constituents (electrons and planets). Most students failed to apply Newton's third law to either system. There was a considerable difference in the extent to which respondents were able to identify the type of force acting in the systems (nearly all for the solar system, but only a small proportion in the case of the atom). The findings are considered in terms of both the limitations of students' understanding of the basic physics and possible implications for the use of the teaching analogy.
Taber, Keith S.
Quantum-nondemolition measurements using cold trapped atoms: Comparison between theory and experiment
In this paper we present a detailed theoretical analysis of a recent quantum-nondemolition experiment in optics using cold atoms in a magneto-optical trap as a nonlinear medium. A signal beam and a meter beam from two independent lasers are coupled within a Lambda-type three-level scheme in the D1 line of 87Rb atoms. The experimental results for the relevant quantum correlations
A. Sinatra; J. F. Roch; K. Vigneron; Ph. Grelu; J.-Ph. Poizat; Kaige Wang; P. Grangier
Resolving all-order method convergence problems for atomic physics applications
The development of the relativistic all-order method where all single, double, and partial triple excitations of the Dirac-Hartree-Fock wave function are included to all orders of perturbation theory led to many important results for the study of fundamental symmetries, development of atomic clocks, ultracold atom physics, and others, as well as provided recommended values of many atomic properties critically evaluated for their accuracy for a large number of monovalent systems. This approach requires iterative solutions of the linearized coupled-cluster equations leading to convergence issues in some cases where correlation corrections are particularly large or lead to an oscillating pattern. Moreover, these issues also lead to similar problems in the configuration-interaction (CI)+all-order method for many-particle systems. In this work, we have resolved most of the known convergence problems by applying two different convergence stabilizer methods, namely, reduced linear equation and direct inversion of iterative subspace. Examples are presented for B, Al, Zn{sup +}, and Yb{sup +}. Solving these convergence problems greatly expands the number of atomic species that can be treated with the all-order methods and is anticipated to facilitate many interesting future applications.
Gharibnejad, H.; Derevianko, A. [Department of Physics, University of Nevada, Reno, Nevada 89557 (United States); Eliav, E. [Department of Chemistry, Tel Aviv University, Tel Aviv (Israel); Safronova, M. S. [Department of Physics, University of Delaware, Newark, Delaware 19716 (United States)
Large dynamic range silicon photomultipliers for high energy physics experiments
NASA Astrophysics Data System (ADS)
Silicon Photomultipliers (SiPM) are very promising devices for high energy physics (HEP) experiments due to their high photon detection effciency, miniaturized device size and insensitivity to high magnetic fields. Most often detectors are exposed to a high radiation dose for which reason the performance should degrade only minor under the applied radiation load. Decreasing the active depth of a SiPM microcell should help to strengthen the radiation hardness. Additionally for high energy particle physics experiments a large dynamic range is mandatory. This was a further driving reason at KETEK to scale down the microcell pitch and thereby losing only small amount in geometrical efficiency. With these large dynamic range SiPMs a photon detection efficiency in blue spectral range of 32% for 2500 microcells=mm2 and 22% for 4400 microcells=mm2 was achieved. With an improved fabrication technology the dark noise level was decreased to about 250 kHz=mm2 at 20% overvoltage, while the gain variation was still less than 1%=K. Further optimization of the depleted region increased the sensitivity in the output wavelength range of common scintillators (515 nm) by 20% compared to the standard devices. The performance of the KETEK SiPMs will be discussed in detail.
Ganka, Th.; Dietzinger, Ch.; Iskra, P.; Wiest, F.; Fojt, R.; Hansch, W.
Physical mechanism of the Schwarzschild effect in film dosimetry�theoretical model and comparison with experiments
NASA Astrophysics Data System (ADS)
In consideration of the importance of film dosimetry for the dosimetric verification of IMRT treatment plans, the Schwarzschild effect or failure of the reciprocity law, i.e. the reduction of the net optical density under 'protraction' or 'fractionation' conditions at constant dose, has been experimentally studied for Kodak XOMAT-V (Martens et al 2002 Phys. Med. Biol. 47 2221-34) and EDR 2 dosimetry films (Djouguela et al 2005 Phys. Med. Biol. 50 N317-N321). It is known that this effect results from the competition between two solid-state physics reactions involved in the latent-image formation of the AgBr crystals, the aggregation of two Ag atoms freshly formed from Ag+ ions near radiation-induced occupied electron traps and the spontaneous decomposition of the Ag atoms. In this paper, we are developing a mathematical model of this mechanism which shows that the interplay of the mean lifetime ? of the Ag atoms with the time pattern of the irradiation determines the magnitude of the observed effects of the temporal dose distribution on the net optical density. By comparing this theory with our previous protraction experiments and recent fractionation experiments in which the duration of the pause between fractions was varied, a value of the time constant ? of roughly 10 s at room temperature has been determined for EDR 2. The numerical magnitude of the Schwarzschild effect in dosimetry films under the conditions generally met in radiotherapy amounts to only a few per cent of the net optical density (net OD), so that it can frequently be neglected from the viewpoint of clinical applications. But knowledge of the solid-state physical mechanism and a description in terms of a mathematical model involving a typical time constant of about 10 s are now available to estimate the magnitude of the effect should the necessity arise, i.e. in cases of large fluctuations of the temporal pattern of film exposure.
Djouguela, A.; Kollhoff, R.; R�hmann, A.; Willborn, K. C.; Harder, D.; Poppe, B.
Correlations of a single atom and a resonance mode and their manifestation in some physical phenomena
NASA Astrophysics Data System (ADS)
A kinetic equation governing relaxation of a single two-level atom and a high- Q cavity mode in an entangled thermostat exhibiting quantum correlations is presented. Based on two kinds of collective operators, we demonstrate the possibility of the existence of dual squeezed states in this system. One kind of generator of collective operators corresponds to algebra obtained by polynomial deformation of the angular-momentum algebra, while the other kind corresponds to the Heisenberg-Weyl algebra. Squeezed states of the collective system are defined in terms of commutative relations for operators of the corresponding generator algebras. It is shown that quantum correlations in the system manifest themselves in two physical phenomena. The first one is the known entanglement-swapping protocol and is based on the projection measurement. In the other case, quantum correlations reveal themselves in the coherent scattering dynamics of an atom in the field of a standing light wave.
Gorbachev, V. N.; Trubilko, A. I.
Double beta decay: A problem of particle, nuclear and atomic physics
NASA Astrophysics Data System (ADS)
A brief review of recent progress in the field of double beta decay is presented. Different aspects from particle, nuclear and atomic physics of both two-neutrino ( 2???) and neutrinoless ( 0???) modes of the double ? decay are discussed. It is argued that the R-parity violating supersymmetry ( ? RpSUSY) contributes to the 0???-decay predominantly via charged pion-exchange between decaying nucleons. Further, a problem of reliable determination of the 0???-decay nuclear matrix elements (NMEs) is addressed. It is manifested that the uncertainty associated with the calculation of the 0???-decay NMEs can be diminished by suitably chosen nuclear probes. A new possibility for the study of lepton number non-conservation is proposed, namely oscillations plus deexcitations of neutral atoms. A phenomenological analysis of this process leads to a resonant enhancement of the neutrinoless double electron capture, that has a Breit-Wigner form.
�imkovic, Fedor
Testing for a cosmological influence on local physics using atomic and gravitational clocks
NASA Technical Reports Server (NTRS)
The existence of a possible influence of the large-scale structure of the universe on local physics is discussed. A particular realization of such an influence is discussed in terms of the behavior in time of atomic and gravitational clocks. Two natural categories of metric theories embodying a cosmic infuence exist. The first category has geodesic equations of motion in atomic units, while the second category has geodesic equations of motion in gravitational units. Equations of motion for test bodies are derived for both categories of theories in the appropriate parametrized post-Newtonian limit and are applied to the Solar System. Ranging data to the Viking lander on Mars are of sufficient precision to reveal (1) if such a cosmological influence exists at the level of Hubble's constant, and (2) which category of theories is appropriate for a descripton of the phenomenon.
Adams, P. J.; Hellings, R. W.; Canuto, V. M.; Goldman, I.
Atomic physics studies of highly charged ions on tokamaks using x-ray spectroscopy
An overview is given of atomic physics issues which have been studied on tokamaks with the help resolution x-ray spectroscopy. The issues include the testing of model calculations predicting the excitation of line radiation, the determination of rate coefficients, and accurate atomic structure measurements. Recent research has focussed primarily on highly charged heliumlike (22 less than or equal to Z less than or equal to 28) and neonlike (34 less than or equal to Z less than or equal to 63) ions, and results are presented from measurements on the PLT and TFTR tokamaks. Many of the measurements have been aided by improved instrumental design and new measuring techniques. Remarkable agreement has been found between measurements and theory in most cases. However, in this review those areas are stressed where agreement is worst and where further investigations are needed. 19 refs., 13 figs., 2 tabs.
Beiersdorfer, P.; von Goeler, S.; Bitter, M.; Hill, K.W.
Planar position sensitive Ge(i)- and Si(Li)-detector systems for Compton Polarimetry in Atomic Physics with Highly Charged Ions
NASA Astrophysics Data System (ADS)
Planar position-, energy-, and time-dispersive semiconductor detector systems have shown their excellent performance in Compton Polarimetry and X-ray Imaging in the realm of Atomic Physics Experiments with Highly Charged Ions. We report on two of these detector systems and discuss the importance of this kind of detector systems for the present and future experimental programm of the SPARC collaboration at GSI and FAIR.
Spillmann, U.; Blumenhagen, K.-H.; Br�uning, H.; Weber, G.; St�hlker, Th
EUV, X-ray, and gamma-ray instrumentation for astronomy and atomic physics; Proceedings of the Meeting, San Diego, CA, Aug. 7-11, 1989
Topics discussed in this volume include hard X-ray and gamma-ray imaging techniques, hard X-ray and gamma-ray spectroscopic and imaging detectors, X-ray\\/EUV solid-state imagers, balloon and spaceborne experiments and missions, laboratory atomic physics instrumentation, and proportional counter detectors. Other topics discussed are high-resolution X-ray spectrometers, detector calibration, position readout techniques, and X-ray\\/EUV optics for astronomy and microscopy. Papers are presented on
Charles J. Hailey; Oswald H. W. Siegmund
Report of the Joint Seminar on Solid State Physics, Atomic and Molecular Physics, and Materials Science in the Energy Region of Tandem Accelerators
The Joint Seminar on Solid State Physics, Atomic and Molecular Physics, and Materials Science in the Energy Region of Tandem Acceleration was held at Tokai Research Establishment of JAERI for two days from January 22 to 23, 1991. About 60 physicists and material scientists participated and 18 papers were presented in this seminar. The topics presented in this seminar included
Yukio Kazumata
Results From the Physics of Colloids Experiment on ISS
NASA Technical Reports Server (NTRS)
The Physics of Colloids in Space (PCS) experiment was accommodated within International Space Station (ISS) EXpedite the PRocessing of Experiments to Space Station (EXPRESS) Rack 2 and was remotely operated from early June 2001 until February 2002 from NASA Glenn Research Center's Telescience Support Center (TSC) in Cleveland, Ohio, and from the remote site at Harvard University in Cambridge, Massachusetts. PCS was launched on 4/19/2001 on Space Shuttle STS-100. The experiment was activated on 5/31/2001. The entire experimental setup performed remarkably well, and accomplished 2400 hours of science operations on-orbit. The sophisticated instrumentation in PCS is capable of dynamic and static light scattering from 11 to 169 degrees, Bragg scattering over the range from 10 to 60 degrees, dynamic and static light scattering at low angles from 0.3 to 6.0 degrees, and color imaging. The long duration microgravity environment on the ISS facilitated extended studies on the growth and coarsening characteristics of binary crystals. The de-mixing of the colloid-polymer critical-point sample was also studied as it phase-separated into two phases. Further, aging studies on a col-pol gel, gelation rate studies in extremely low concentration fractal gels over several days, and studies on a glass sample, all provided valuable information. Several exciting and unique aspects of these results are discussed here.
Weitz, David; Bailey, Arthur; Manley, Suliana; Prasad, Vikram; Christianson, Rebecca; Sankaran, Subramanian; Doherty, Michael; Jankovsky, Amy; Lorik, Tibor; Shiley, William
Results From the Physics of Colloids Experiment on ISS
NASA Astrophysics Data System (ADS)
The Physics of Colloids in Space (PCS) experiment was accommodated within International Space Station (ISS) EXpedite the PRocessing of Experiments to Space Station (EXPRESS) Rack 2 and was remotely operated from early June 2001 until February 2002 from NASA Glenn Research Center's Telescience Support Center (TSC) in Cleveland, Ohio, and from the remote site at Harvard University in Cambridge, Massachusetts. PCS was launched on 4/19/2001 on Space Shuttle STS-100. The experiment was activated on 5/31/2001. The entire experimental setup performed remarkably well, and accomplished 2400 hours of science operations on-orbit. The sophisticated instrumentation in PCS is capable of dynamic and static light scattering from 11 to 169 degrees, Bragg scattering over the range from 10 to 60 degrees, dynamic and static light scattering at low angles from 0.3 to 6.0 degrees, and color imaging. The long duration microgravity environment on the ISS facilitated extended studies on the growth and coarsening characteristics of binary crystals. The de-mixing of the colloid-polymer critical-point sample was also studied as it phase-separated into two phases. Further, aging studies on a col-pol gel, gelation rate studies in extremely low concentration fractal gels over several days, and studies on a glass sample, all provided valuable information. Several exciting and unique aspects of these results are discussed here.
Weitz, David; Bailey, Arthur; Manley, Suliana; Prasad, Vikram; Christianson, Rebecca; Sankaran, Subramanian; Doherty, Michael; Jankovsky, Amy; Lorik, Tibor; Shiley, William
Initial Physics Results From the National Spherical Torus Experiment
The mission of the National Spherical Torus Experiment (NSTX) is to extend the understanding of toroidal physics to low aspect ratio (R/a approximately equal to 1.25) in low collisionality regimes. NSTX is designed to operate with up to 6 MW of High Harmonic Fast Wave (HHFW) heating and current drive, 5 MW of Neutral Beam Injection (NBI) and Co-Axial Helicity Injection (CHI) for non-inductive startup. Initial experiments focused on establishing conditions that will allow NSTX to achieve its aims of simultaneous high-bt and high-bootstrap current fraction, and to develop methods for non-inductive operation, which will be necessary for Spherical Torus power plants. Ohmic discharges with plasma currents up to 1 MA and with a range of shapes and configurations were produced. Density limits in deuterium and helium reached 80% and 120% of the Greenwald limit respectively. Significant electron heating was observed with up to 2.3 MW of HHFW. Up to 270 kA of toroidal current for up to 200 msec was produced noninductively using CHI. Initial NBI experiments were carried out with up to two beam sources (3.2 MW). Plasmas with stored energies of up to 140 kJ and bt =21% were produced.
Kaye, S.M.; Bell, M.G.; Bell, R.E.; Bialek, J. [and others
Physics results from the National Spherical Torus Experiment
The mission of the National Spherical Torus Experiment (NSTX) is to extend the understanding of toroidal physics to low aspect ratio (R/a {approx} 1.25) in low collisionality regimes. NSTX is designed to operate with up to 6 MW of High Harmonic Fast Wave (HHFW) heating and current drive, 5 MW of Neutral Beam Injection (NBI), and Co-Axial Helicity Injection (CHI) for non-inductive startup. Initial experiments focused on establishing conditions that will allow NSTX to achieve its aims of simultaneous high-{beta}{sub t} and high-bootstrap current fraction, and to develop methods for non-inductive operation, which will be necessary for Spherical Torus power plants. Ohmic discharges with plasma currents up to 1 MA, stored energies up to 55 kJ, {beta}{sub t} {approx} 10%, and a range of shapes and configurations were produced. Density limits in deuterium and helium reached 80% and 120% of the Greenwald limit respectively. Significant electron heating was observed with up to 2.3 MW of HHFW. Up to 270 kA of toroidal current for up to 200 msec was produced noninductively using CHI. Initial NBI experiments were carried out with up to two beam sources (3.2 MW). Plasmas with stored energies of up to 140 kJ and {beta}{sub t}=21% were produced.
Kaye, S.; Bell, M. [and others
Physics Potential of a 2540 Km Baseline Superbeam Experiment
We study the physics potential of a neutrino superbeam experiment with a 2540 km baseline. We assume a neutrino beam similar to the NuMI beam in the medium energy configuration. We consider a 100 kton totally active scintillator detector at a 7 mr off-axis location. We find that such a configuration has an outstanding hierarchy discriminating capability. In conjunction with the data from the present reactor neutrino experiments, it can determine the neutrino mass hierarchy at the 3{sigma} level in less than 5 years, if sin{sup 2}2{theta}{sub 13}{>=}0.01, running in the neutrino mode alone. As a stand alone experiment, with a 5 year neutrino run and a 5 year anti-neutrino run, it can determine non-zero {theta}{sub 13} at the 3{sigma} level if sin{sup 2} 2{theta}{sub 13}{>=}7x10{sup -3} and hierarchy at the 3{sigma} level if sin{sup 2}2{theta}{sub 13}{>=}8x10{sup -3}. This data can also distinguish {delta}{sub CP} = {pi}/2 from the CP conserving values of 0 and {pi}, for sin{sup 2}2{theta}{sub 13}{>=}0.02.
Joglekar, Aniket [Department of Physics, Indian Institute of Technology Bombay, Mumbai (India); Address after August 1, 2010 Department of Physics, University of Chicago, Chicago, IL (United States); Prakash, Suprabh; Raut, Sushant K.; Sankar, S. Uma [Department of Physics, Indian Institute of Technology Bombay, Mumbai (India)
Atomic Layer Deposition of Metal Oxide Patterns on Nonwoven Fiber Mats using Localized Physical Compression.
Patterning is an essential part of many industrial processes from printing to semiconductor manufacturing. In this work, we demonstrate a new method to pattern and selectively coat nonwoven textiles by atomic layer deposition (ALD) using compressive mask patterning. A physical mask combined with mechanical compression allows lateral definition and fidelity of the ALD coating to be controlled. We produce features of several sizes on different nonwoven fiber materials and demonstrate the ability to limit diffusion effects to within <200 ?m of the pattern edge. Lateral and vertical penetration of reactive growth species into nonwoven mats is investigated by plan-view and cross-sectional imaging. Vertical growth is also analyzed by imaging coating depth into fiber mat stacks. We develop a fully quantitative transport model that describes well the effect of fiber structure and mechanical compression on the extent of coating under the physical mask. This method could be implemented for high-volume patterning for applications including flexible electronics. PMID:24850237
Sweet, William J; Oldham, Christopher J; Parsons, Gregory N
EDITORIAL: The 20th European Sectional Conference on Atomic and Molecular Physics of Ionized Gases The 20th European Sectional Conference on Atomic and Molecular Physics of Ionized Gases
This special issue consists of papers that are associated with invited lectures, workshop papers and hot topic papers presented at the 20th European Sectional Conference on Atomic and Molecular Physics of Ionized Gases (ESCAMPIG XX). This conference was organized in Novi Sad (Serbia) from 13 to 17 July 2010 by the Institute of Physics of the University of Belgrade. It
Zoran Lj Petrovic; Dragana Maric; Gordana Malovic
Atom Skimmers and Atom Lasers Utilizing Them
NASA Technical Reports Server (NTRS)
Atom skimmers are devices that act as low-pass velocity filters for atoms in thermal atomic beams. An atom skimmer operating in conjunction with a suitable thermal atomic-beam source (e.g., an oven in which cesium is heated) can serve as a source of slow atoms for a magneto-optical trap or other apparatus in an atomic-physics experiment. Phenomena that are studied in such apparatuses include Bose-Einstein condensation of atomic gases, spectra of trapped atoms, and collisions of slowly moving atoms. An atom skimmer includes a curved, low-thermal-conduction tube that leads from the outlet of a thermal atomic-beam source to the inlet of a magneto-optical trap or other device in which the selected low-velocity atoms are to be used. Permanent rare-earth magnets are placed around the tube in a yoke of high-magnetic-permeability material to establish a quadrupole or octupole magnetic field leading from the source to the trap. The atoms are attracted to the locus of minimum magnetic-field intensity in the middle of the tube, and the gradient of the magnetic field provides centripetal force that guides the atoms around the curve along the axis of the tube. The threshold velocity for guiding is dictated by the gradient of the magnetic field and the radius of curvature of the tube. Atoms moving at lesser velocities are successfully guided; faster atoms strike the tube wall and are lost from the beam.
Hulet, Randall; Tollett, Jeff; Franke, Kurt; Moss, Steve; Sackett, Charles; Gerton, Jordan; Ghaffari, Bita; McAlexander, W.; Strecker, K.; Homan, D.
Results on QCD Physics from the CDF-II Experiment
In this paper the authors review a selection of recent results obtained, in the area of QCD physics, from the CDF-II experiment that studies p{bar p} collisions at {radical}s = 1.96 TeV provided by the Fermilab Tevatron Collider. All results shown correspond to analysis performed using the Tevatron Run II data samples. In particular they will illustrate the progress achieved and the status of the studies on the following QCD processes: jet inclusive production, using different jet clustering algorithm, W({yields} e{nu}{sub e}) + jets and Z({yields} e{sup +}e{sup -}) + jets production, {gamma} + b-jet production, dijet production in double pomeron exchange and finally exclusive e{sup +}e{sup -} and {gamma}{gamma} production. No deviations from the Standard Model have been observed so far.
Pagliarone, C.; /Cassino U. /INFN, Pisa
Hydrogen atom recombination on tungsten at high temperature: Experiment and Molecular Dynamics Simulation
NASA Astrophysics Data System (ADS)
Atom recombination at wall is a phenomenon involved in many plasma experiments and also in present tokamaks and future fusion plasma reactors like ITER. This exothermic surface reaction is catalyzed by the material and depends on its composition and temperature. In the MESOX experimental set-up, several methods were developed for the measurement of the recombination parameters. In this paper, a method developed for the experimental evaluation of the recombination coefficient of atomic hydrogen ?H on tungsten at high temperature is presented using two series of atomic lines (H? and He or H? and H2) and the results obtained for surface temperature up to 1350 K are given. A Molecular Dynamics Simulation has been done for the recombination of hydrogen atoms on tungsten in conditions close to the experimental ones using a semi-classical collisional method. Modeling results are compared to the experimental data for two surface temperature values and a fairly good agreement was obtained.
Rutigliano, M.; Santoro, D.; Balat-Pichelin, M.
Science Goals of the Primary Atomic Reference Clock in Space (PARCS) Experiment
NASA Technical Reports Server (NTRS)
The PARCS (Primary Atomic Reference Clock in Space) experiment will use a laser-cooled Cesium atomic clock operating in the microgravity environment aboard the International Space Station (ISS) to provide both advanced tests of gravitational theory and to demonstrate a new cold-atom clock technology for space. PARCS is a joint project of the National Institute of Standards and Technology (NIST), NASA's Jet Propulsion Laboratory (JPL), and the University of Colorado (CU). This paper concentrates on the scientific goals of the PARCS mission. The microgravity space environment allows laser-cooled Cs atoms to have Ramsey times in excess of those feasible on Earth, resulting in improved clock performance. Clock stabilities of 5x10(exp -14) at one second, and accuracies better than 10(exp -16) are projected.
Ashby, N.
Inertial confinement fusion ablator physics experiments on Saturn and Nova
The Saturn pulsed power accelerator [R. B. Spielman {ital et al.}, in {ital Proceedings of the 2nd International Conference on Dense} Z-{ital pinches}, Laguna Beach, CA, 1989, edited by N. R. Pereira, J. Davis, and N. Rostoker (American Institute of Physics, New York, 1989), p. 3] at Sandia National Laboratories (SNL) and the Nova laser [J. T. Hunt and D. R. Speck, Opt. Eng. {bold 28}, 461 (1989)] at Lawrence Livermore National Laboratory (LLNL) have been used to explore techniques for studying the behavior of ablator material in x-ray radiation environments comparable in magnitude, spectrum, and duration to those that would be experienced in National Ignition Facility (NIF) hohlraums [J. D. Lindl, Phys. Plasmas {bold 2}, 3933 (1995)]. The large x-ray outputs available from the Saturn pulsed-power-driven z pinch have enabled us to drive hohlraums of full NIF ignition scale size at radiation temperatures and time scales comparable to those required for the low-power foot pulse of an ignition capsule. The high-intensity drives available in the Nova laser have allowed us to study capsule ablator physics in smaller-scale hohlraums at radiation temperatures and time scales relevant to the peak power pulse for an ignition capsule. Taken together, these experiments have pointed the way to possible techniques for testing radiation-hydrodynamics code predictions of radiation flow, opacity, equation of state, and ablator shock velocity over the range of radiation environments that will be encountered in a NIF hohlraum. {copyright} {ital 1997 American Institute of Physics.}
Olson, R.E.; Porter, J.L.; Chandler, G.A.; Fehl, D.L.; Jobe, D.O.; Leeper, R.J.; Matzen, M.K.; McGurn, J.S.; Noack, D.D.; Ruggles, L.E.; Sawyer, P.; Torres, J.A.; Vargas, M.; Zagar, D.M. [Sandia National Laboratories, Albuquerque, New Mexico 87185 (United States)] [Sandia National Laboratories, Albuquerque, New Mexico 87185 (United States); Kornblum, H.N.; Orzechowski, T.J.; Phillion, D.W.; Suter, L.J.; Thiessen, A.R.; Wallace, R.J. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)] [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)
Power supplies and quench protection for the Tokamak Physics Experiment
The Tokamak Physics Experiment (TPX) is an advanced tokamak project aimed at the production of quasi-steady state plasmas with advanced shape, heating, and particle control. TPX is to be built at the Princeton Plasma Physics Laboratory (PPPL) using many of the facilities from the Tokamak Fusion Test Reactor (TFTR). First plasma is scheduled for the year 2000. TPX will be the first tokamak to utilize superconducting (SC) magnets in both the toroidal field (TF) and poloidal field (PF) systems. This is a new feature which requires not only a departure from the traditional tokamak power supply schemes but also that ultra-reliable quench protection devices be used to rapidly discharge the stored energy from the magnets in the event of a quench. This paper describes the plan and basis for the adaptation and augmentation of the PPPL/TFTR power system facilities to supply TPX. Following a description of the basic operational requirements, four major areas are addressed, namely the AC power system, the TF power supply, the PF power supply, and quench protection for the TF and PF systems.
Neumeyer, C.L. [Raytheon Engineers & Constructors, Princeton, NJ (United States). EBASCO Div.
Determination of Calcium in Cereal with Flame Atomic Absorption Spectroscopy: An Experiment for a Quantitative Methods of Analysis Course
ERIC Educational Resources Information Center
An experiment for determination of calcium in cereal using two-increment standard addition method in conjunction with flame atomic absorption spectroscopy (FAAS) is demonstrated. The experiment is intended to introduce students to the principles of atomic absorption spectroscopy giving them hands on experience using quantitative methods of�
Bazzi, Ali; Kreuz, Bette; Fischer, Jeffrey
Oxygen control of atomic structure and physical properties of SrRuO3 surfaces.
Complex oxide thin films and heterostructures have become one of the foci for condensed matter physics research due to a broad variety of properties they exhibit. Similar to the bulk, properties of oxide surfaces can be expected to be strongly affected by oxygen stoichiometry. Here we explore the coupling between atomic structure and physical properties of SrRuO3 (SRO), one of the most well-studied oxide materials. We perform a detailed in situ and ex situ experimental investigation of the surfaces of SRO thin films using a combination of scanning tunneling microscopy (STM), X-ray and ultraviolet photoelectron spectroscopy, SQUID magnetometry, and magnetotransport measurements, as well as ab initio modeling. A number of remarkable linear surface reconstructions were observed by STM and interpreted as oxygen adatoms, favorably adsorbed in a regular rectangular or zigzag patterns. The degree of oxygen coverage and different surface patterns change the work function of the thin films, and modify local electronic and magnetic properties of the topmost atomic layer. The ab initio modeling reveals that oxygen adatoms possess frustrated local spin moments with possible spin-glass behavior of the surface covered by adsorbed oxygen. Additionally, the modeling indicates presence of a pseudo gap on the topmost SrO layer on pristine SrO-terminated surface, suggesting possibility for realization of a surface half-metallic film. PMID:23570268
Tselev, Alexander; Ganesh, P; Qiao, Liang; Siemons, Wolter; Gai, Zheng; Biegalski, Michael D; Baddorf, Arthur P; Kalinin, Sergei V
From Atom-Picoseconds to Centimeter-Years in Simulation and Experiment
The final report for a Laboratory Directed Research and Development project entitled, ''From Atom-Picoseconds to Centimeter-Years in Simulation and Experiment'' is presented. In this project, separate modeling methods at the atomic scale were used to bridge gaps in time and space with higher scales. For understanding of continuum mechanics quantities at various scales atomistic simulations that ranged from nanometers to microns were performed and experiments from centimeters to millimeters were performed. Certain continuum mechanical quantities were clearly defined as a function of size scale, for example, the yield stress. Several techniques were used to extend the time scale of simulations, including calculating prefactors and activation energies for diffusion events and mapping complex atomic motions onto more tractable lattice models. In the case of transport of small molecules in polymeric and nanoporous materials, new Monte Carlo methods for sampling transition rates were developed.
M.F. Horstemeyer; J.C. Hamilton; A. Thompson; M.I. Baskes; S.J. Plimpton; I. Daruka; M.R. Sorenson; A.F. Voter; D.M. Ford; P.S. Rallabandi; C. Tunca
Sixteenth International Conference on the physics of electronic and atomic collisions
This report contains abstracts of papers on the following topics: photons, electron-atom collisions; electron-molecule collisions; electron-ion collisions; collisions involving exotic species; ion- atom collisions, ion-molecule or atom-molecule collisions; atom-atom collisions; ion-ion collisions; collisions involving rydberg atoms; field assisted collisions; collisions involving clusters and collisions involving condensed matter.
Dalgarno, A.; Freund, R.S.; Lubell, M.S.; Lucatorto, T.B. (eds.)
Simulations of the edge plasma: the role of atomic, molecular and surface physics
NASA Astrophysics Data System (ADS)
Atomic, molecular and surface physics plays an important role in simulations of the edge plasma in present day tokamaks, and in the predictive simulations of new devices. The edge plasma-in this context, the Scrape-Off Layer (SOL), the Private Flux Region (PFR) and core region close to the separatrix (or Last Closed Flux Surface, LCFS)-provides the boundary conditions for the main plasma, and is the region where much of the power and all of the particle exhaust occurs. It is also the region where the plasma interacts with solid surfaces, puffed gases and gas arising from recycling. The results of plasma edge simulations can depend strongly on the availability and quality of the atomic, molecular and surface data (the peak plasma temperature at the divertor was found to vary by a factor of five dependent on the choice of atomic physics data in a recent sensitivity analysis). The current material choice for ITER with Plasma Facing Components (PFCs) consisting of C, Be and W also presents challenges, both in the availability of the necessary data for W, and in the plethora of charge states for W. Another challenge presented by the material choice is the likely presence of mixed materials formed by the migration of material from one surface to another. These introduce effects like alloying and preferential sputtering as well as new (much longer) time-scales in the problem. Efforts to incorporate a bundled charge state model within one of the present edge simulation codes, SOLPS, will be described, as well as efforts to address some of the questions raised by mixed materials. Some issues related to data consistency and traceability within the context of the European effort on Integrated Tokamak Modelling will also be addressed.
Coster, D. P.; Bonnin, X.; Reiter, D.; Kukushkin, A.; Gori, S.; Krstic, P.; Strand, P.; Eriksson, L.-G.
Simulations of the edge plasma: the role of atomic, molecular and surface physics
Atomic, molecular and surface physics plays an important role in simulations of the edge plasma in present day tokamaks, and in the predictive simulations of new devices. The edge plasma - in this context, the Scrape-Off Layer (SOL), the Private Flux Region (PFR) and core region close to the separatrix (or Last Closed Flux Surface, LCFS) - provides the boundary conditions for the main plasma, and is the region where much of the power and all of the particle exhaust occurs. It is also the region where the plasma interacts with solid surfaces, puffed gases and gas arising from recycling. The results of plasma edge simulations can depend strongly on the availability and quality of the atomic, molecular and surface data (the peak plasma temperature at the divertor was found to vary by a factor of five dependent on the choice of atomic physics data in a recent sensitivity analysis). The current material choice for ITER with Plasma Facing Components (PFCs) consisting of C, Be and W also presents challenges, both in the availability of the necessary data for W, and in the plethora of charge states for W. Another challenge presented by the material choice is the likely presence of mixed materials formed by the migration of material from one surface to another. These introduce effects like alloying and preferential sputtering as well as new (much longer) time-scales in the problem.Efforts to incorporate a bundled charge state model within one of the present edge simulation codes, SOLPS, will be described, as well as efforts to address some of the questions raised by mixed materials. Some issues related to data consistency and traceability within the context of the European effort on Integrated Tokamak Modelling will also be addressed.
Coster, D. P.; Gori, S. [Max-Planck-Institut fuer Plasmaphysik, EURATOM Association, D-85748 Garching (Germany); Bonnin, X. [CNRS-LIMHP, Universite Paris 13, F-93430 Villetaneuse (France); Reiter, D. [Institut fuer Plasmaphysik, FZ Juelich, EURATOM Association, Juelich (Germany); Kukushkin, A. [ITER Organization, Cadarache (France); Krstic, P. [Oak Ridge National Laboratory, Oak Ridge, TN (United States); Strand, P. [Chalmers University, Gothenburg (Sweden); Eriksson, L.-G. [CEA, IRFM, F-13108 Saint-Paul-lez-Durance (France)
Physics Results from the National Spherical Torus Experiment
NASA Astrophysics Data System (ADS)
The National Spherical Torus Experiment (NSTX) will produce plasmas with R/a=0.85/0.68 m 1.25, I_p= 1 MA, BT <=0.6 T, ?<=2.2, ?<=0.5, with 6 MW of High Harmonic Fast Wave (HHFW) heating and current drive, 5 MW of Neutral Beam Injection (NBI) and Co-axial Helicity Injection (CHI) for non-inductive startup to establish the physics principles of low aspect ratio. Outboard passive conducting plates aid vertical stability and suppression of low-n modes. During the initial set of physics experiments, studies of poloidal flux consumption indicated an optimal current ramp rate of 5 MA/sec, with higher ramp rates limited by m=2 oscillations and Internal Reconnection Events possibly related to impurity accumulation and double tearing modes. Flux consumption optimization and real-time plasma control led to the achievement of ohmic discharges with 1 MA plasma current and stored energies up to 48 kJ and ?T 9%. Inboard limited and single and double-null diverted plasmas over a wide range of ? and ? were produced. The density limit, so far, is consistent with the Hugill limit, which is about 60% of the Greenwald limit, and it was characterized by growing and locking m=1 oscillations, followed by a series of Reconnection Events. The q-limit was manifest as growing and locking 2/1 perturbations leading to severe kinking of the plasma surface and subsequent discharge termination as q_cyl decreased below 2. Initial observations of edge turbulence indicated filamentary structures with ?_perp 10 cm. Up to 2 MW of HHFW power was coupled to the plasma, with increases in stored energy observed for waves with k_parallel=14 m-1, but not at higher phase velocity. CHI experiments on NSTX produced up to 130 kA of toroidal current for up to 100 msec. NBI heating is planned for late September 2000. This work has been supported at PPPL by U.S. DOE Contract # DE-AC02-76CH03073.
Kaye, S. M.
Non-local physics: Applications from the universe evolution to the atom structure in the frame of the unified theory
NASA Astrophysics Data System (ADS)
The main principles of the non-local physics are delivered. The unified theory of transport processes is applicable to the physical systems in tremendous diapason of scales - from atom structures to the Universe evolution. The origin of difficulties connected with the hypothetical dark matter and dark energy consists in the total Oversimplification following from the principles of local physics and reflects the general shortcomings of the local kinetic transport theory.
Alexeev, B. V.
Comparison of Numerical Simulations to Experiments for Atomization in a Jet Nebulizer
The development of jet nebulizers for medical purposes is an important challenge of aerosol therapy. The performance of a nebulizer is characterized by its output rate of droplets with a diameter under 5 �m. However the optimization of this parameter through experiments has reached a plateau. The purpose of this study is to design a numerical model simulating the nebulization process and to compare it with experimental data. Such a model could provide a better understanding of the atomization process and the parameters influencing the nebulizer output. A model based on the Updraft nebulizer (Hudson) was designed with ANSYS Workbench. Boundary conditions were set with experimental data then transient 3D calculations were run on a 4 �m mesh with ANSYS Fluent. Two air flow rate (2 L/min and 8 L/min, limits of the operating range) were considered to account for different turbulence regimes. Numerical and experimental results were compared according to phenomenology and droplet size. The behavior of the liquid was compared to images acquired through shadowgraphy with a CCD Camera. Three experimental methods, laser diffractometry, phase Doppler anemometry (PDA) and shadowgraphy were used to characterize the droplet size distributions. Camera images showed similar patterns as numerical results. Droplet sizes obtained numerically are overestimated in relation to PDA and diffractometry, which only consider spherical droplets. However, at both flow rates, size distributions extracted from numerical image processing were similar to distributions obtained from shadowgraphy image processing. The simulation then provides a good understanding and prediction of the phenomena involved in the fragmentation of droplets over 10 �m. The laws of dynamics apply to droplets down to 1 �m, so we can assume the continuity of the distribution and extrapolate the results for droplets between 1 and 10 �m. So, this model could help predicting nebulizer output with defined geometrical and physical parameters.
Lelong, Nicolas; Vecellio, Laurent; Sommer de Gelicourt, Yann; Tanguy, Christian; Diot, Patrice; Junqua-Moullet, Alexandra
Comparison of numerical simulations to experiments for atomization in a jet nebulizer.
The development of jet nebulizers for medical purposes is an important challenge of aerosol therapy. The performance of a nebulizer is characterized by its output rate of droplets with a diameter under 5 �m. However the optimization of this parameter through experiments has reached a plateau. The purpose of this study is to design a numerical model simulating the nebulization process and to compare it with experimental data. Such a model could provide a better understanding of the atomization process and the parameters influencing the nebulizer output. A model based on the Updraft nebulizer (Hudson) was designed with ANSYS Workbench. Boundary conditions were set with experimental data then transient 3D calculations were run on a 4 �m mesh with ANSYS Fluent. Two air flow rate (2 L/min and 8 L/min, limits of the operating range) were considered to account for different turbulence regimes. Numerical and experimental results were compared according to phenomenology and droplet size. The behavior of the liquid was compared to images acquired through shadowgraphy with a CCD Camera. Three experimental methods, laser diffractometry, phase Doppler anemometry (PDA) and shadowgraphy were used to characterize the droplet size distributions. Camera images showed similar patterns as numerical results. Droplet sizes obtained numerically are overestimated in relation to PDA and diffractometry, which only consider spherical droplets. However, at both flow rates, size distributions extracted from numerical image processing were similar to distributions obtained from shadowgraphy image processing. The simulation then provides a good understanding and prediction of the phenomena involved in the fragmentation of droplets over 10 �m. The laws of dynamics apply to droplets down to 1 �m, so we can assume the continuity of the distribution and extrapolate the results for droplets between 1 and 10 �m. So, this model could help predicting nebulizer output with defined geometrical and physical parameters. PMID:24244334
Lelong, Nicolas; Vecellio, Laurent; Sommer de G�licourt, Yann; Tanguy, Christian; Diot, Patrice; Junqua-Moullet, Alexandra
Atomic Oxygen and Space Environment Effects on Aerospace Materials Flown with EOIM-3 Experiment
NASA Technical Reports Server (NTRS)
Polymer materials samples mounted on a passive carrier tray were flown aboard the STS-46 Atlantis shuttle as complement to the EOIM-3 (Evaluation of Oxygen Interaction with Materials) experiment to evaluate the effects of atomic oxygen on the materials and to measure the gaseous shuttle bay environment. The morphological changes of the samples produced by the atomic oxygen fluence of 2.07 x 10(exp 20) atoms/cm(exp 2) are being reported. The changes have been verified using Electron Spectroscopy for Chemical Analysis (ESCA), gravimetric measurement, microscopic observations and thermo-optical measurements. The samples, including Kapton, Delrin, epoxies, Beta Cloth, Chemglaze Z306, silver Teflon, silicone coatings, 3M tape and Uralane and Ultem, PEEK, Victrex (PES), Polyethersulfone and Polymethylpentene thermoplastic, have been characterized by their oxygen reaction efficiency on the basis of their erosion losses and the oxygen fluence. Those efficiencies have been compared to results from other experiments, when available. The efficiencies of the samples are all in the range of E-24 g/atom. The results indicate that the reaction efficiencies of the reported materials can be grouped in about three ranges of values. The least affected materials which have efficiencies varying from 1 to 10(exp 25) g/atom, include silicones, epoxies, Uralane and Teflon. A second group with efficiency from 10 to 45(exp 25) g/atom includes additional silicone coatings, the Chemglaze Z306 paint and Kapton. The third range from 50 to 75(exp 25) includes organic compound such as Pentene, Peek, Ultem, Sulfone and a 3M tape. A Delrin sample had the highest reaction efficiency of 179(exp 25) g/atom. Two samples, the aluminum Beta cloth X389-7 and the epoxy fiberglass G-11 nonflame retardant, showed a slight mass increase.
Scialdone, John J.; Clatterbuck, Carroll H.; Ayres-Treusdell, Mary; Park, Gloria; Kolos, Diane
Atomically resolved STM imaging with a diamond tip: simulation and experiment.
The spatial resolution of a scanning tunneling microscope (STM) can be enhanced using light element-terminated probes with spatially localized electron orbitals at the apex atom. Conductive diamond probes can provide carbon atomic orbitals suitable for STM imaging with sub-�ngstr�m lateral resolution and high apex stability crucial for the small tunneling gaps necessary for high-resolution experiments. Here we demonstrate that high spatial resolution can be achieved in STM experiments with single-crystal diamond tips, which are generally only considered for use as probes for atomic force microscopy. The results of STM experiments with a heavily boron-doped, diamond probe on a graphite surface; density functional theory calculations of the tip and surface electronic structure; and first-principles tunneling current calculations demonstrate that the highest spatial resolution can be achieved with diamond tips at tip-sample distances of 3-5 � when frontier p-orbitals of the tip provide their maximum contribution to the tunneling current. At the same time, atomic resolution is feasible even at extremely small gaps with very high noise in the tunneling current. PMID:24334653
Grushko, V; L�bben, O; Chaika, A N; Novikov, N; Mitskevich, E; Chepugov, A; Lysenko, O; Murphy, B E; Krasnikov, S A; Shvets, I V
Phase diagram of the anisotropic Anderson transition with the atomic kicked rotor: theory and experiment
NASA Astrophysics Data System (ADS)
We realize experimentally a cold-atom system, the quasiperiodic kicked rotor, equivalent to the three-dimensional Anderson model of disordered solids where the anisotropy between the x direction and the y-z plane can be controlled by adjusting an experimentally accessible parameter. This allows us to study experimentally the disorder versus anisotropy phase diagram of the Anderson metal-insulator transition. Numerical and experimental data compare very well with each other and a theoretical analysis based on the self-consistent theory of localization correctly describes the observed behavior, illustrating the flexibility of cold-atom experiments for the study of transport phenomena in complex quantum systems.
Lopez, Matthias; Cl�ment, Jean-Fran�ois; Lemari�, Gabriel; Delande, Dominique; Szriftgiser, Pascal; Garreau, Jean Claude
Application of the nuclear liquid drop model to atomic and molecular physics problems
The liquid drop model is applied to describe some basic properties of atoms, homoatomic molecules, metallic clusters of atoms and fullerene molecules. Equilibrium atomic size, energy and polarizability of the atom are calculated. Collective modes of oscillations (dipole, quadrupole and monopole, or breathing, ones) are regarded. Electromagnetic radiation by an atom, passing through a barrier is studied. Equilibrium volume of
M. Ya. Amusia; Y. Kornyushin
Using the Franck-Hertz experiment to illustrate quantization; Energy states of the neon atom by electron impact
That microscopic matter exists in quantized states can be demonstrated with modern versions of historic experiments: atomic line spectra, resonance potentials, and blackbody radiation. The resonance potentials of mercury were discovered by Franck and Hertz in 1914. Their experiment consisted of bombarding atoms by electrons, and detecting the kinetic energy loss of the scattered electrons. Prior to the Franck-Hertz experiment, spectroscopic work by Balmer and rydberg revealed that atoms emitted radiation at discrete energies. The Franck-Hertz experiment showed directly that quantized energy levels in an atom are real, not just optical artifacts. An atom can be raised to excited states by inelastic collisions with electrons as well as lowered from excited states by emission of photons. The classic Franck-Hertz experiment is carried out with mercury. Here the authors present an experiment for the study of resonance potentials using neon.
Kash, M.M.; Shields, G.C. (Lake Forest Coll., IL (United States))
Experimenting in a constructivist high school physics laboratory
NASA Astrophysics Data System (ADS)
Although laboratory activities have long been recognized for their potential to facilitate the learning of science concepts and skills, this potential has yet to be realized. To remediate this problem, researchers have called for constructivist learning environments in which students can pursue open inquiry and frame their own research problems. The present study was designed to describe and understand students' experimenting and problem solving in such an environment. An interpretive research methodology was adopted for the construction of meaning from the data. The data sources included videotapes, their transcripts, student laboratory reports and reflections, interviews with the students, and the teacher's course outline and reflective notes. Forty-six students from three sections of an introductory physics course taught at a private school for boys participated in the study. This article shows the students' remarkable ability and willingness to generate research questions and to design and develop apparatus for data collection. In their effort to frame research questions, students often used narrative explanations to explore and think about the phenomena to be studied. In some cases, blind alleys, students framed research questions and planned experiments that did not lead to the expected results. We observed a remarkable flexibility to deal with problems that arose during the implementation of their plans in the context of the inquiry. These problems, as well as their solutions and the necessary decision-making processes, were characterized by their situated nature. Finally, students pursued meaningful learning during the interpretation of data and graphs to arrive at reasonable answers of their research questions. We concluded that students should be provided with problem-rich learning environments in which they learn to investigate phenomena of their own interest and in which they can develop complex problem-solving skills.
Roth, Wolff-Michael
Review study and evaluation of possible flight experiments relating to cloud physics experiments in space
NASA Technical Reports Server (NTRS)
The general objectives of the Zero-Gravity Atmospheric Cloud Physics Laboratory Program are to improve the level of knowledge in atmospheric cloud research by placing at the disposal of the terrestrial-bound atmospheric cloud physicist a laboratory that can be operated in the environment of zero-gravity or near zero-gravity. This laboratory will allow studies to be performed without mechanical, aerodynamic, electrical, or other techniques to support the object under study. The inhouse analysis of the Skylab 3 and 4 experiments in dynamics of oscillations, rotations, collisions and coalescence of water droplets under low gravity-environment is presented.
Hunt, R. J.; Wu, S. T.
Quench Detection and Instrumentation for the Tokamak Physics Experiment magnets
The design of the Local Instrumentation & Control (I&C) System for the Tokamak Physics Experiment (TPX) superconducting PF & TF magnets is presented. The local I&C system monitors the status of the magnet systems and initiates the proper control sequences to protect the magnets from any foreseeable fault. Local I&C also stores magnet-system data for analysis and archiving. Quench Detection for the TPX magnets must use a minimum of two independent sensing methods and is allowed a detection time of one second. Proposed detection methods include the measurement of; (1) normal-zone resistive voltage, (2) cooling-path helium flow, (3) local temperature in the winding pack, (4) local pressure in the winding pack. Fiber-optic based isolation systems are used to remove high common-mode magnet voltages and eliminate ground loops. The data acquisition and fault-detection systems are computer based. The design of the local I&C system incorporates redundant, fault-tolerant, and/or fail-safe features at all component levels. As part of a quench detection R&D plan, a Quench Detection Model Coil has been proposed to test all detection methods. Initial cost estimates and schedule for the local I&C system are presented.
Chaplin, M.R.; Hassenzahl, W.V. [Lawrence Livermore National Lab., CA (United States); Schultz, J.H. [Massachusetts Inst. of Tech., Cambridge, MA (United States). Plasma Fusion Center
The Spheromak Turbulence Experiment: The Next Phase in Spheromak Physics
NASA Astrophysics Data System (ADS)
The spheromak turbulence experiment (STPX) is a collaboration between FAMU, WVU, Auburn University, and Woodruff Scientific, Inc. The fundamental purpose of STPX is to advance Spheromak physics toward producing a burning plasma and new insights on astrophysical systems with magnetic reconnection. FAMU will employ microwave pulses to manipulate the stable state. In addition, closely coupled NIMROD modeling and experimentation will take place using the FAMU computational cluster. Auburn University is providing a pair of movable probe arrays consisting of a triple probe and a series of four saturation current/floating potential probes for making instantaneous measurements of plasma parameters. West Virginia University is providing an array of (N), X-MHz, B-dot coils for making measurements of magnetic fluctuations. West Virginia University is also providing an array of 25, 2 MHz bandwidth, B-dot coils and differential amplifiers for making high time-resolution measurements of magnetic fluctuations at the edge of the plasma. Woodruff Scientific designed and constructed the STPX vessel.
Mezonlin, Ephrem; Williams, Kyron; Weatherford, C. A.; Johnson, J. A., III; Alexander, A. B.; Scime, Earl; Keesee, A.; Lusk, G.; Reynolds, E.; Vandervort, R.; Arnold, N. I.; Gilmore, K.; Thomas, E., Jr.; Woodruff, Simon
Experiences developing ALEGRA: A C++ coupled physics framework
ALEGRA is a coupled physics framework originally written to simulate inertial confinement fusion (ICF) experiments being conducted at the PBFA-II facility at Sandia National Laboratories. It has since grown into a large software development project supporting a number of computational programs at Sandia. As the project has grown, so has the development team, from the original two authors to a group of over fifteen programmers crossing several departments. In addition, ALEGRA now runs on a wide variety of platforms, from large PCs to the ASCI Teraflops massively parallel supercomputer. The authors discuss the reasons for ALEGRA`s success, which include the intelligent use of object-oriented techniques and the choice of C++ as the programming language. They argue that the intelligent use of development tools, such as build tools (e.g. make), compiler, debugging environment (e.g. dbx), version control system (e.g. cvs), and bug management software (e.g. ClearDDTS), is nearly as important as the choice of language and paradigm.
Budge, K.G.; Peery, J.S.
Automated computer vision interpretation for physical and genetic mapping experiments
Much of the high-throughput data currently generated in the molecular genetics laboratory is in the form of two dimensional images. In physical mapping, a high-density gridded filter containing thousands YACs or cosmids can be hybridized against a single labeled probe, such as the IRS-PCR products of a radiation hybrid (RH). In genetic mapping, hundreds of polymorphic dinucleotide repeat PCR experiments can be multiplexed into distinct lanes, size ranges, and fluorescent colors on a single run of an Applied Biosystems (ABl) 373A automated DNA sequencer. For all its advantages such high-throughput data introduces a new fundamental bottleneck: the greatly increased time, expense, and error of scoring these assays when relying solely on the human visual system. Toward this end, we have developed a novel computer vision automation architecture that addresses the needs of high-throughput data interpretation in the molecular genetics laboratory. A flexible knowledge-based approach is used to systematically detect and analyze signal features, motivated by how human experts perform the interpretation. This architecture enables customization to similar hybridization-and gel-based tasks. Our prototype system has thus far been tested on both hybridization data and ABl gel images.
Pathak, D.K.; Perlin, M.W. [Carnegie Mellon Univ., Pittsburgh, PA (United States)
Lower hybrid system design for the Tokamak physics experiment
The lower hybrid (LH) launcher configuration has been redesigned to integrate the functions of the vertical four-way power splitter and the front waveguide array (front array). This permits 256 waveguide channels to be fed by only 64 waveguides at the vacuum window interface. The resulting configuration is a more compact coupler, which incorporates the simplicity of a multijunction coupler while preserving the spectral flexibility of a conventional lower hybrid launcher. Other spin-offs of the redesign are reduction in thermal incompatibility between the front array and vacuum windows, improved maintainability, in situ vacuum window replacement, a reduced number of radio frequency (rf) connections, and a weight reduction of 7300 kg. There should be a significant cost reduction as well. Issues associated with the launcher design and fabrication have been addressed by a research and development program that includes brazing of the front array and testing of the power splitter configuration to confirm that phase errors due to reflections in the shorted splitter legs will not significantly impact the rf spectrum. The Conceptual Design Review requires that radiation levels at the torus radial port mounting flange and outer surface of the toroidal field coils should be sufficiently low to permit hands-on maintenance. Low activation materials and neutron shielding are incorporated in the launcher design to meet these requirements. The launcher is configured to couple 3 MW of steady state LH heating/LH current drive power at 3.7 GHz to the Tokamak Physics Experiment plasma.
Goranson, P.L.; Conner, D.L.; Swain, D.W.; Yugo, J.J. [Oak Ridge National Lab., TN (United States); Bernabei, S.; Greenough, N. [Princeton Univ., NJ (United States). Plasma Physics Lab.
Quench detection and instrumentation for the Tokamak Physics Experiment magnets
NASA Astrophysics Data System (ADS)
The design of the local instrumentation and control (I&C) system for the Tokamak Physics Experiment (TPX) superconducting poloidal-field (PF) and toroidal-field (TF) magnets is presented. The local I&C system monitors the status of the magnet systems and initiates the proper control sequences to protect the magnets from any foreseeable fault. Local I&C also stores magnet-system data for analysis and archiving. Quench detection for the TPX magnets must use a minimum of two independent sensing methods and is allowed a detection time of one second. Proposed detection methods include the measurement of normal-zone resistive voltage, cooling-path helium flow, local temperature in the winding pack, and local pressure in the winding pack. Fiber optic based isolation systems are used to remove high common-mode magnet voltages and eliminate ground loops. The data acquisition and fault detection systems are computer based. The design of the local I&C system incorporates redundant, fault tolerant, and/or fail-safe features at all component levels. As part of a quench detection research and development plan, a quench detection model coil has been proposed to test all detection methods. Initial cost estimates and schedule for the local I&C system are presented.
Chaplin, M. R.; Hassenzahl, W. V.; Schultz, J. H.
The AMS Measurements and Its Applications in Nuclear Physics at China Institute of Atomic Energy (CIAE)
Accelerator Mass Spectrometry (AMS), initiated in late 1970s at McMaster university based on the accelerator and detector technique, has long been applied in the studies on archaeology, geology, and cosmology, as a powerful tool for isotope dating. The advantages of AMS in the analysis of rare nuclides by direct counting of the atoms, small sample size and relatively free from the interferences of molecular ions have been well documented. This paper emphasizes that AMS can not only be used for archaeology, geology, environment, biology and so on, but also served as a unique tool for nuclear physics research. In this paper, the determination of the half-lives of {sup 79}Se, the measurements of the cross-sections of {sup 93}Nb(n,2n){sup 92g}Nb and {sup 238}U(n,3n){sup 236}U reactions, the detection and determination of ultratrace impurities in neutrino detector materials, and the measurement of the fission product nuclide {sup 126}Sn, are to be introduced, as some of examples of AMS applications in nuclear research conducted in AMS lab of China Institute of Atomic Energy. Searching for superheavy nuclides by using AMS is being planned.
Jiang Shan; Shen Hongtao; He Ming; Dong Kejun; He Guozhu; Wang Xianggao; Yuan Jian; Wang Wei; Wu Shaoyong [China Institute of Atomic Energy, P.O.Box 275-80, Beijing 102413 (China); Ruan Xiangdong; Wu Weimin [College of Physics, Guangxi University, Nanning 530004 (China)
Nuclear effects in atomic transitions
Atomic electrons are sensitive to the properties of the nucleus they are bound to, such as nuclear mass, charge distribution, spin, magnetization distribution, or even excited level scheme. These nuclear parameters are reflected in the atomic transition energies. A very precise determination of atomic spectra may thus reveal information about the nucleus, otherwise hardly accessible via nuclear physics experiments. This
Adriana Palffy
The use of cylindrical lenses in easy experiments for physics education and the magic arts
The purpose of this article is to present the properties of cylindrical lenses and provide some examples of their use in easy school physics experiments. Such experiments could be successfully conducted in the context of science education, in fun experiments that teach physics and in science fair projects, or used to entertain an audience by staging tricks, effects or illusions
Stanislaw Bednarek; Jerzy Krysiak
The Use of Cylindrical Lenses in Easy Experiments for Physics Education and the Magic Arts
ERIC Educational Resources Information Center
The purpose of this article is to present the properties of cylindrical lenses and provide some examples of their use in easy school physics experiments. Such experiments could be successfully conducted in the context of science education, in fun experiments that teach physics and in science fair projects, or used to entertain an audience by�
Bednarek, Stanislaw; Krysiak, Jerzy
Experiences that influence a student's choice on majoring in physics
NASA Astrophysics Data System (ADS)
Currently the production of college graduates with science and engineering degrees is insufficient to fill the increasing number of jobs requiring these skills. This study focuses on physics majors with an in-depth examination of student transitions from high school to college. Many different areas of influence could affect a student's decision to major in physics. The first phase of this study addresses all of the potential areas of influence identified from the literature. The goal was to identify common influences that might be used to increase students' interest in majoring in physics. Subjects (N=35) from the first phase were recruited from physics majors at diverse Michigan colleges and universities. The second phase of this study explored, in more depth, important areas of influence identified in the first phase of the study. Subjects (N=94) from the second phase were recruited from diverse colleges and universities in Indiana, Illinois, and Ohio. The interviews were also conducted via email. Approximately half of the students in the study decided to major in physics while still in high school. Their reasons relate to many of the areas of influence. For example, high school physics teachers were cited as a strong influence in many students' decisions to major in physics. Influential physics teachers were described as being helpful, encouraging and interesting. The teachers also need to be their students' number one cheerleader and not their number one critic. Some areas of influence were found to be different for males vs. females. A high percentage of all physics majors had influential adults with careers in physical or biological science fields. This percentage was even larger for female physics majors. Female students also showed a greater initial interest in astronomy than the male students. Thus, high school and college physics teachers should seek to expose students to science-related careers and adults with these careers. Astronomy is also an important and often over looked entry into physics.
Dobbin, Donya Rae
ATOMIC AND MOLECULAR PHYSICS: Wavefunction and energy of the 1s22sns configuration in a beryllium atom
NASA Astrophysics Data System (ADS)
A new set of trial functions for 1s22sns configurations in a beryllium atom is suggested. A Mathematica program based on the variational method is developed to calculate the wavefunctions and energies of 1s22sns (n = 3-6) configurations in a beryllium atom. Non-relativistic energy, polarization correction and relativistic correction which include mass correction, one-and two-body Darwin corrections, spin-spin contact interaction and orbit-orbit interaction, are calculated respectively. The results are in good agreement with experimental data.
Huang, Shi-Zhong; Ma, Kun; Yu, Jia-Ming; Liu, Fen
On the physical role of exchange in the formation of an intramolecular bond path between two electronegative atoms
NASA Astrophysics Data System (ADS)
In this paper, we present a detailed energetic decomposition of intramolecular O...X interactions (X being O, S, or a halogen atom) based on the interacting quantum atoms approach of Pend�s and co-workers. The nature of these interactions (repulsive or attractive, more or less electrostatic) is discussed in the framework of Bader's atoms in molecules theory, a particular emphasis being put on delocalization (measured by delocalization indexes and in terms of the source function) and on the exchange contributions. Notably, the concept of exchange channels introduced by Pend�s and collaborators provides means of rationalizing and predicting the presence of bond critical points, enhancing the physical meaning of bond paths.
Tognetti, Vincent; Joubert, Laurent
Beta-decay experiments of neutral atoms in a magneto-optical trap
Magneto optical traps (MOT) allow the cooling and storing of neutral atoms in a volume of a few cubic millimeters by use of\\u000a laser beams and a magnetic field. Such devices offer new and exciting opportunities for precision measurements of radioactive\\u000a isotopes. Here we present experiments performed with a double-MOT system coupled to the on-line separator TISOL at TRIUMF\\/Vancouver,\\u000a Canada.
J. Dilling; J. A. Behr; A. Gorelov; T. Swanson; O. H�usser; D. Melconian; K. P. Jackson; M. Trinczek; U. Giesen; J. M. D�Auria
Stochastic optimization of a cold atom experiment using a genetic algorithm
NASA Astrophysics Data System (ADS)
We employ an evolutionary algorithm to automatically optimize different stages of a cold atom experiment without human intervention. This approach closes the loop between computer based experimental control systems and automatic real time analysis and can be applied to a wide range of experimental situations. The genetic algorithm quickly and reliably converges to the most performing parameter set independent of the starting population. Especially in many-dimensional or connected parameter spaces, the automatic optimization outperforms a manual search.
Rohringer, W.; B�cker, R.; Manz, S.; Betz, T.; Koller, Ch.; G�bel, M.; Perrin, A.; Schmiedmayer, J.; Schumm, T.
The superconducting magnet system for the Tokamak Physics Experiment
The superconducting magnet system for the Tokamak Physics experiment (TPX) will be the first all superconducting magnet system for a Tokamak, where the poloidal field coils, in addition to the toroidal field coils are superconducting. The magnet system is designed to operate in a steady state mode, and to initiate the plasma discharge ohmically. The toroidal field system provides a peak field of 4.0 Tesla on the plasma axis at a plasma major radius of 2.25 m. The peak field on the niobium 3-tin, cable-in-conduit (CIC) conductor is 8.4 Tesla for the 16 toroidal field coils. The toroidal field coils must absorb approximately 5 kW due to nuclear heating, eddy currents, and other sources. The poloidal field system provides a total of 18 volt seconds to initiate the plasma and drive a plasma current up to 2 MA. The poloidal field system consists of 14 individual coils which are arranged symmetrically above and below the horizontal mid plane. Four pairs of coils make up the central solenoid, and three paris of poloidal ring coils complete the system. The poloidal field coils all use a cable-in-conduit conductor, using either niobium 3-tin (NB{sub 3}Sn) or niobium titanium (NbTi) superconducting strands depending on the operating conditions for that coil. All of the coils are cooled by flowing supercritical helium, with inlet and outlet connections made on each double pancake. The superconducting magnet system has gone through a conceptual design review, and is in preliminary design started by the LLNL/MIT/PPPL collaboration. A number of changes have been made in the design since the conceptual design review, and are described in this paper.
Lang, D.D.; Bulmer, R.J.; Chaplin, M.R. [and others
Berry phases for quadratic spin Hamiltonians taken from atomic and solid state physics: examples of Abelian gauge fields not connected to physical particles
This paper contains an evaluation of the Berry phases associated with the following class of nonlinear spin Hamiltonians : H (B, n ) = 03B3S S � B + 03B3Q((S � n)2 - S2\\/3), with B � n = 0. Examples of these Hamiltonians are given in Atomic and Solid State Physics. We compute exactly the Berry phases for S
C. Bouchiat
Competing atomic processes in Ba and Sr injection critical velocity experiments
NASA Technical Reports Server (NTRS)
The critical ionization velocity effect requires a superthermal electron population to ionize through collisional impact. Such superthermal electrons can however lose energy to competing atomic processes, as well as to ionization, thus limiting the efficiency of the effect. Considering Ba and Sr magnetospheric injection experiments designed to test the CIV theory, it is found that in both cases roughly 60 percent of the superthermal electron energy is lost on exciting line radiation. Moreover, energy loss to background neutral oxygen places a strict limit on the injected cloud densities for which critical velocity effects are possible; a finding which explains the consistently negative results in radial injection experiments.
Newell, P. T.; Torbert, R. B.
Theoretical atomic and molecular physics: Progress report, July 1, 1987June 30,1988
In this first year of the grant, emphasis has been placed on theoretical investigations of: differential elastic and charge-transfer scattering and alignment and orientation of the excited electron cloud in ion-atom, atom-atom and ion-molecule collisions, using a molecular-orbital representation; quenching of low-lying Rydberg states of a Na atom in a collision with a ground-state He atom, using a semiclassical representation;
"Got Disc?" The "Ultimate" Experience in Physical Education
ERIC Educational Resources Information Center
A quality physical education program is one in which students are exposed to and can participate in a variety of sports and activities. One activity that is increasing in popularity in and outside of physical education is the game of "Ultimate." Opportunities to play Ultimate are increasing rapidly in intramural programs and community and�
Johnson, Tyler G.; Darst, Paul W.; Brusseau, Timothy A.
Peer Influence on Children's Physical Activity: An Experience Sampling Study
on their activity intensity and whether the activity was solitary or with others for seven consecutive days. Results Children were more likely to report more intense physical activity when in the company of peers or close friends. Overweight children reported greater physical activity when in the presence of peers than did lean children; however, overweight children also reported more time
Sarah-Jeanne Salvy; Julie Wojslawowicz Bowker; James N. Roemmich; Natalie Romero; Elizabeth Kieffer; Rocco Paluch; Leonard H. Epstein
Physics basis for the Fusion Ignition Research Experiment (FIRE)
Understanding the properties of high gain (alpha-dominated) fusion plasmas in an advanced toroidal configuration is a critical issue that must be addressed to provide the scientific foundation for an attractive magnetic fusion reactor. The functional fusion plasma objectives for major next physics steps in magnetic fusion research can be described as: Burning Plasma Physics - The achievement and understanding of
D. M. Meade; S. C. Jardin; N. R. Sauthoff; P. J. Heitzenroeder; J. H. Schultz; P. H. Rutherford; J. A. Schmidt; J. C. Wesley; K. M. Young; B. E. Nelson
Expected Performance of the ATLAS Experiment - Detector, Trigger and Physics
A detailed study is presented of the expected performance of the ATLAS detector. The reconstruction of tracks, leptons, photons, missing energy and jets is investigated, together with the performance of b-tagging and the trigger. The physics potential for a variety of interesting physics processes, within the Standard Model and beyond, is examined. The study comprises a series of notes based
G. Aad; E. Abat; B. Abbott; J. Abdallah; A. A. Abdelalim; A. Abdesselam; O. Abdinov; B. Abi; M. Abolins; H. Abramowicz; B. S. Acharya; D. L. Adams; T. N. Addy; C. Adorisio; P. Adragna; T. Adye; J. A. Aguilar-Saavedra; M. Aharrouche; S. P. Ahlen; F. Ahles; A. Ahmad; H. Ahmed; G. Aielli; T. Akdogan; T. P. A. Akesson; G. Akimoto; M. S. Alam; M. A. Alam; J. Albert; S. Albrand; M. Aleksa; I. N. Aleksandrov; F. Alessandria; C. Alexa; G. Alexander; G. Alexandre; T. Alexopoulos; M. Alhroob; G. Alimonti; J. Alison; M. Aliyev; P. P. Allport; S. E. Allwood-Spiers; A. Aloisio; R. Alon; A. Alonso; J. Alonso; M. G. Alviggi; K. Amako; P. Amaral; C. Amelung; V. V. Ammosov; A. Amorim; G. Amoros; N. Amram; C. Anastopoulos; C. F. Anders; K. J. Anderson; A. Andreazza; V. Andrei; M-L. Andrieux; X. S. Anduaga; F. Anghinolfi; A. Antonaki; M. Antonelli; S. Antonelli; B. Antunovic; F. A. Anulli; G. Arabidze; I. Aracena; Y. Arai; A. T. H. Arce; J. P. Archambault; S. Arfaoui; J-F. Arguin; T. Argyropoulos; E. Arik; M. Arik; A. J. Armbruster; O. Arnaez; C. Arnault; A. Artamonov; D. Arutinov; M. Asai; S. Asai; S. Ask; B. Asman; D. Asner; L. Asquith; K. Assamagan; A. Astbury; A. Astvatsatourov; T. Atkinson; G. Atoian; B. Auerbach; E. Auge; K. Augsten; M. A. Aurousseau; N. Austin; G. Avolio; R. Avramidou; A. Axen; C. Ay; G. Azuelos; Y. Azuma; M. A. Baak; G. Baccaglioni; C. Bacci; H. Bachacou; K. Bachas; M. Backes; E. Badescu; P. Bagnaia; Y. Bai; D. C. Bailey; J. T. Baines; O. K. Baker; F. Baltasar Dos Santos Pedrosa; E. Banas; S. Banerjee; D. Banfi; A. Bangert; V. Bansal; S. P. Baranov; A. Barashkou; T. B. Barber; E. L. Barberio; D. Barberis; M. B. Barbero; D. Y. Bardin; T. Barillari; M. Barisonzi; T. Barklow; N. B. Barlow; N. B. Barlow; R. M. Barnett; S. Baron; A. Baroncelli; A. Baroncelli; F. Barreiro; J. Barreiro Guimaraes da Costa; P. Barrillon; R. Bartoldus; D. Bartsch; J. Bastos; R. L. Bates; J. R. Batley; A. Battaglia; M. Battistin; F. Bauer; M. Bazalova; B. Beare; P. H. Beauchemin; R. B. Beccherle; N. Becerici; P. Bechtle; G. A. Beck; H. P. Beck; M. Beckingham; K. H. Becks; I. Bedajanek; A. J. Beddall; P. Bednar; V. A. Bednyakov; C. Bee; S. Behar Harpaz; P. K. Behera; M. Beimforde; C. Belanger-Champagne; P. J. Bell; W. H. Bell; G. Bella; L. Bellagamba; F. Bellina; M. Bellomo; A. Belloni; K. Belotskiy; O. Beltramello; S. Ben Ami; O. Beltramello; D. Benchekroun; M. Bendel; B. H. Benedict; N. Benekos; Y. Benhammou; G. P. Benincasa; D. P. Benjamin; M. Benoit; J. R. Bensinger; K. Benslama; S. Bentvelsen; M. Beretta; D. Berge; E. Bergeaas Kuutmann; N. Berger; F. Berghaus; E. Berglund; J. Beringer; K. Bernardet; P. Bernat; R. Bernhard; C. Bernius; T. Berry; A. Bertin; N. Besson; S. Bethke; R. M. Bianchi; M. Bianco; O. Biebel; J. Biesiada; M. Biglietti; H. Bilokon; S. Binet; A. Bingul; C. Bini; C. Biscarat; M. Bischofberger; U. Bitenc; K. M. Black; R. E. Blair; G. Blanchot; C. Blocker; J. Blocki; A. Blondel; W. Blum; U. Blumenschein; C. Boaretto; G. J. Bobbink; A. Bocci; B. Bodine; J. Boek; N. Boelaert; S. Boeser; J. A. Bogaerts; A. Bogouch; C. Bohm; J. Bohm; V. Boisvert; T. Bold; V. Boldea; V. G. Bondarenko; M. Bondioli; M. Boonekamp; C. N. Booth; P. S. L. Booth; J. R. A. Booth; A. Borisov; G. Borissov; I. Borjanovic; S. Borroni; K. Bos; D. Boscherini; M. Bosman; M. Bosteels; H. Boterenbrood; J. Bouchami; J. Boudreau; E. V. Bouhova-Thacker; C. Boulahouache; C. Bourdarios; J. Boyd; I. R. Boyko; A. Braem; P. Branchini; G. W. Brandenburg; A. Brandt; O. Brandt; U. Bratzler; J. E. Brau; H. M. Braun; B. Brelier; J. Bremer; R. Brenner; S. Bressler; D. Breton; N. D. Brett; D. Breton; F. M. Brochu; I. Brock; R. Brock; E. Brodet; F. Broggi; G. Brooijmans; W. K. Brooks; E. Brubaker; P. A. Bruckman de Renstrom; D. Bruncko; R. Bruneliere; S. Brunet; A. Bruni; G. Bruni; M. Bruschi; T. Buanes; F. B. Bucci; P. Buchholz; A. G. Buckley; I. A. Budagov; V. Buescher; L. Bugge; F. Bujor; O. Bulekov; M. Bunse; T. Buran; H. Burckhart; S. Burdin; S. Burke; E. Busato; C. P. Buszello; F. Butin; B. Butler; J. M. Butler; C. M. Buttar; J. M. Butterworth; T. Byatt; S. Cabrera Urban; D. Caforio; O. Cakir; P. Calafiura; G. Calderini; R. Calkins; L. P. Caloba; R. Calkins; D. Calvet; P. Camarri; M. Cambiaghi; D. Cameron; F. Campabadal Segura; S. Campana; M. Campanelli; V. Canale; J. Cantero; M. D. M. Capeans Garrido; I. Caprini; M. D. M. Capeans Garrido; M. Capua; R. Caputo; C. Caramarcu; R. Cardarelli; T. Carli; G. Carlino; L. Carminati; B. Caron; S. Caron; S. Carron Montero; A. A. Carter; J. R. Carter; J. Carvalho; D. Casadei; M. P. Casado; M. Cascella; C. Caso; A. M. Castaneda Hernadez; E. Castaneda Miranda; V. Castillo Gimenez; N. F. Castro; G. Cataldi; A. Catinaccio; J. R. Catmore; A. Catinaccio; G. Cattani; S. Caughron; D. Cauz; P. Cavalleri; D. Cavalli; M. Cavalli-Sforza; V. Cavasinni; A. Cazzato
Physics Demonstration Experiments at William Jewell College. Revised Edition.
ERIC Educational Resources Information Center
Presented are descriptions (with photographs) of demonstration equipment purchased, assembled, developed, and used at William Jewell College (Missouri) during the past 25 years. The descriptions are organized into the following topic areas: (1) mechanics; (2) heat; (3) waves, sound, and acoustics; (4) electricity; (5) optics; and (6) atomic and�
Hilton, Wallace A.
Accelerator Preparations for Muon Physics Experiments at Fermilab
The use of existing Fermilab facilities to provide beams for two muon experiments - the Muon to Electron Conversion Experiment (Mu2e) and the New g-2 Experiment - is under consideration. Plans are being pursued to perform these experiments following the completion of the Tevatron Collider Run II, utilizing the beam lines and storage rings used today for antiproton accumulation without considerable reconfiguration. Operating scenarios being investigated and anticipated accelerator improvements or reconfigurations will be presented.
Syphers, M.J.; /Fermilab
Physics of Hard Spheres Experiment (PhaSE) or 'Making Jello in Space'.
National Technical Information Service (NTIS)
The Physics of Hard Spheres Experiment (PHaSE) is a highly successful experiment that flew aboard two shuttle missions to study the transitions involved in the formation of jellolike colloidal crystals in a microgravity environment. A colloidal suspension...
J. S. Ling M. P. Doherty
Getting Physical with Your Chemistry: Mechanically Investigating Local Structure and Properties of Surfaces with the Atomic Force Microscope
ERIC Educational Resources Information Center
Atomic force microscope (AFM) investigates mechanically the chemical properties of individual molecules, surfaces, and materials using suitably designed probes. The current state of the art of AFM in terms of imaging, force measurement, and sample manipulation and its application to physical chemistry is discussed.
Heinz, William F.; Hoh, Jan H.
Microgravity experiments in the field of physical chemistry in Japan
NASA Astrophysics Data System (ADS)
Japan has been operating 'KIBO' (`hope' in Japanese) as Japanese experimental module on ISS (International Space Station) to perform researches on physical, life, medical, space sciences in space. Several research racks and facilities have already been accommodated in the pressurized module of 'KIBO' and some researches have already been carried out. Japan currently has 17 ISS flight projects (including 4 candidates) in the field of physical sciences and also incubates new projects through are search support program named as 'research WG (Working Group)', where 25 research WGs are active in the field of physical sciences. Those include 1 flight candidate and 2 research WGs in the field of physical chemistry. The article introduces those to promote international collaborations.
Natsuisaka, M.; Tsujii, K.; Shimomura, M.; Yabu, H.; Hirai, Y.; Mashiko, T.; Deguchi, S.; Mukai, S.; Inoue, Y.; Nishiyama, Y.; Sawada, M.; Okumura, K.; Sakamoto, K.
Simple Laser Scattering Experiment for Biology-Oriented Physics Labs.
ERIC Educational Resources Information Center
Describes a physics exercise designed for biology and premed majors. The activity is a low intensity laser light scattering laboratory exercise to determine the diameter of micron-sized latex spheres (simulated microbes) in water suspension. (GA)
Orwig, L.; Schrank, G.
Electron electric dipole moment experiment using electric-fieldquantized slow cesium atoms
A proof-of-principle electron electric dipole moment (e-EDM)experiment using slow cesium atoms, nulled magnetic fields, and electricfield quantization has been performed. With the ambient magnetic fieldsseen by the atoms reduced to less than 200 pT, an electric field of 6MV/m lifts the degeneracy between states of unequal lbar mF rbar and,along with the low (approximately 3 m/s) velocity, suppresses thesystematic effect from the motional magnetic field. The low velocity andsmall residual magnetic field have made it possible to induce transitionsbetween states and to perform state preparation, analysis, and detectionin regions free of applied static magnetic and electric fields. Thisexperiment demonstrates techniques that may be used to improve the e-EDMlimit by two orders of magnitude, but it is not in itself a sensitivee-EDM search, mostly due to limitations of the laser system.
Amini, Jason M.; Munger Jr., Charles T.; Gould, Harvey.
Speed dependence of atomic stick-slip friction in optimally matched experiments and molecular dynamics simulations.
The atomic stick-slip behavior of a Pt tip sliding on a Au(111) surface is studied with atomic force microscopy (AFM) experiments and accelerated (i.e., reduced sliding speed) molecular dynamics (MD) simulations. The MD and AFM conditions are controlled to match, as closely as possible, the geometry and orientation, load, temperature, and compliance. We observe clear stick-slip without any damage. Comparison of both MD and AFM results with the thermally activated Prandtl-Tomlinson model shows that MD results at the highest speeds are not in the thermally activated regime. At lower speeds, within the thermally activated regime, AFM and MD provide consistent energetics, but attempt frequencies differ by orders of magnitude. Because this discrepancy lies in attempt frequencies and not energetics, atomistic details in MD simulations can be reliably used in interpreting AFM data if the MD speeds are slow enough. PMID:21517330
Li, Qunyang; Dong, Yalin; Perez, Danny; Martini, Ashlie; Carpick, Robert W
Beta-decay experiments of neutral atoms in a magneto-optical trap
NASA Astrophysics Data System (ADS)
Magneto optical traps (MOT) allow the cooling and storing of neutral atoms in a volume of a few cubic millimeters by use of laser beams and a magnetic field. Such devices offer new and exciting opportunities for precision measurements of radioactive isotopes. Here we present experiments performed with a double-MOT system coupled to the on-line separator TISOL at TRIUMF/Vancouver, Canada. For the first time, the ?-decay of free atoms stored in such a device could be observed. We report on coincidence measurements between beta-particles and the argon recoils in the decay of 37K and 38rm{m}}K. The charge state ratios of the recoil-ions were deduced by Time-Of-Flight separation in an acceleration field. The final goal of those investigations is a precision test of the Standard Model by measuring the nu-correlation parameter a.
Dilling, J.; Behr, J. A.; Gorelov, A.; Swanson, T.; H�usser, O.; Melconian, D.; Jackson, K. P.; Trinczek, M.; Giesen, U.; D'Auria, J. M.
Removal of Heavy Metals from Water: An Environmentally Significant Atomic Absorption Spectrometry Experiment
NASA Astrophysics Data System (ADS)
A laboratory experiment that combines the environmentally significant topic of wastewater treatment with atomic absorption spectrometry (AAS) is described. In the first portion of the laboratory project, students perform treatment studies on simulated wastewater samples that contain heavy metal contaminants common to the effluent of the metal finishing industry. Following pretreatment reduction of Cr(VI) to Cr(III), sparingly soluble metal hydroxides are produced by pH adjustment and removed by filtration with the aid of a polyacrylamide flocculant. In the second portion of the experiment, AAS is used to determine metal concentrations in treated and untreated water samples, thus enabling the students to determine the effectiveness of the treatment process. Details of how this experiment integrates topics such as the pH-dependent solubility of metal hydroxides, complex equilibria, matrix interference, and polymers in the context of an environmentally important analysis are presented.
Buffin, Brian P.
Taking into account physical and instrumental parameters in atomic absorption spectroscopy with a continuous radiation source
NASA Astrophysics Data System (ADS)
We present a detailed analysis of the dependences of the absorption contours and concentration curves on various parameters in atomic absorption spectrometry with a continuous radiation source. We have developed a multifunctional application software package allowing us to calculate the emission and absorption line profiles for different elements under different physical conditions. We take into account Doppler and collisional broadening of the absorption lines, which have a complex structure as a result of the isotopic shift, hyperfine splitting of the components, and also instrumental distortion of these lines. We consider two different procedures for calculating the absorbance and do a comparative analysis of the two procedures. For all the listed cases, we can plot concentration curves and find the absorbance within the classical definition and plot the concentration curve using only a portion of the spectral width of the profile rather than the entire width. We have modeled the instrumental distortions of the spectral profile due to spectral selection, and we have analyzed their effect on the shape of the absorption contour.
Somov, A. R.; Gil'Mutdinov, A. Kh.; Grishin, L. A.
Atomic and molecular physics of plasma-based environmental technologies for abatement of volatile organic compounds
Non-thermal plasma techniques represent a new generation of air emission control technology that potentially could treat large-volume emissions containing dilute concentrations of volatile organic compounds (VOCs). In order to apply non-thermal plasmas in an industrial scale, it is important to establish the electrical power requirements and byproducts of the process. There is a need for reliable data concerning the primary decomposition mechanisms and subsequent chemical kinetics associated with non-thermal processing of VOCs. There are many basic atomic and molecular physics issues that are essential in evaluating the economic performance of non- thermal plasma reactors. These studies are important in understanding how the input electrical power is dissipated in the plasma and how efficiently it is converted to the production of the plasma species (radicals, ions, or electrons) responsible for the decomposition of the VOCs. This paper will present results from the basic experimental and theoretical studies aimed at identifying the reaction mechanisms responsible for the primary decomposition of various types of VOCs.
Penetrante, B.M.; Hsiao, M.C.; Bardsley, J.N.; Merritt, B.T.; Vogtlin, G.E. [Lawrence Livermore National Lab., CA (United States); Kuthi, A. [Plasma and Materials Technologies, Inc., Chatsworth, CA (United States); Burkhart, C.P.; Bayless, J.R. [First Point Scientific, Inc., Agoura Hills, CA (United States)
An Open Source Atomic Physics Toolkit: First applications to HeI recombination lines
NASA Astrophysics Data System (ADS)
Hydrogen and helium recombination emission lines are used to determine chemical abundances and physical conditions in a variety of objects, and form the foundation for much of our understanding of the chemical evolution of the Universe. We are developing the basic software tools needed to predict recombination line intensities, atomic transition probabilities, photoionization cross-sections, and radiative recombination rate coefficients, for H-like and He-like ions. This work is an improvement over previous calculations since we explicitly take fine structure into account by basing our transition rates on the results of Drake [Phys. Rev. A 46, 2378 (1992)]. We will discuss implications for HeI line formation with application to the primordial helium abundance. Although the needed radiative rates are known to high precision, the collisional rate coefficients involving higher levels of H and He are uncertain by factors of 2 to 3. These introduce 5-20 percent uncertainties in optical and infrared lines for some conditions. Our codes will be made publicly available so that anyone can check the effects of other collisional rates on observed lines, with the hope of promoting further work. This project is supported by the NSF and NASA through grants AST 0071180 and NAG5-8212.
Ferland, G. J.; Bauman, R. P.; MacAdam, K. B.
Physical Science Experiments in K-12 Schools Related to Space
NASA Astrophysics Data System (ADS)
In this talk I shall show movies on the demonstration of surface science experiments at various education levels ranging from middle schools to the university. These experiments demonstrate the concepts of surface tension, surface flows, surface reactions and even miscible interfaces. Experiments that demonstrate capillary effects, pressure variations on account of diameter changes, emulsions and foams will be discussed. Applications involving household agents such as space processing, food and detergents will also be given. All of these experiments are part of a kit that we have assembled for free distribution to area schools.
Narayanan, Ranga
Preliminary design of two Space Shuttle fluid physics experiments
NASA Technical Reports Server (NTRS)
The mid-deck lockers of the STS and the requirements for operating an experiment in this region are described. The design of the surface tension induced convection and the free surface phenomenon experiments use a two locker volume with an experiment unique structure as a housing. A manual mode is developed for the Surface Tension Induced Convection experiment. The fluid is maintained in an accumulator pre-flight. To begin the experiment, a pressurized gas drives the fluid into the experiment container. The fluid is an inert silicone oil and the container material is selected to be comparable. A wound wire heater, located axisymmetrically above the fluid can deliver three wattages to a spot on the fluid surface. These wattages vary from 1-15 watts. Fluid flow is observed through the motion of particles in the fluid. A 5 mw He/Ne laser illuminates the container. Scattered light is recorded by a 35mm camera. The free surface phenomena experiment consists of a trapezoidal cell which is filled from the bottom. The fluid is photographed at high speed using a 35mm camera which incorporated the entire cell length in the field of view. The assembly can incorporate four cells in one flight. For each experiment, an electronics block diagram is provided. A control panel concept is given for the surface induced convection. Both experiments are within the mid-deck locker weight and c-g limits.
Gat, N.; Kropp, J. L.
Chapter 4: A Comparison of Personal Attributes and Experiences among Physically Active and Inactive Children
ERIC Educational Resources Information Center
In this study, the researchers aim to compare the personal attributes and experiences of children who met or exceeded physical activity guidelines with those who did not. By creating profiles, the researchers could compare motor performance, physical fitness, self-efficacy, time spent outdoors during physical activity, social support from friends�
Castelli, Darla M.; Erwin, Heather E.
Tautomerization of Acetylacetone Enol. A Physical Organic Experiment in Kinetics and Thermodynamics.
ERIC Educational Resources Information Center
Describes a physical organic experiment in thermodynamics and kinetics for undergraduate courses in organic chemistry, biochemistry, or physical chemistry. Details background information, solution preparations, equipment and methods, and the suggested experiments such as determination of general-base-catalytic coefficients and the Bronsted�
Spyridis, Greg T.; Meany, J. E.
Zero-gravity cloud physics laboratory: Experiment program definition and preliminary laboratory concept studies
NASA Technical Reports Server (NTRS)
The experiment program definition and preliminary laboratory concept studies on the zero G cloud physics laboratory are reported. This program involves the definition and development of an atmospheric cloud physics laboratory and the selection and delineations of a set of candidate experiments that must utilize the unique environment of zero gravity or near zero gravity.
Eaton, L. R.; Greco, E. V.
Unique separator-spectrometer experiments at the frontiers of nuclear physics: the Super-FRS scientific program
NASA Astrophysics Data System (ADS)
The superconducting fragment separator (Super-FRS) is the magnetic high-resolution spectrometer, which will be coupled to the heavy-ion synchrotron complex at the future Facility for Antiproton and Ion Research FAIR. It will enable a variety of unique nuclear physics experiments. Key examples of the experimental program are presented, for instance the production and study of exotic hypernuclei (i.e.: nuclei far-off stability containing hyperons), the production and study of mesic atoms (i.e.: atoms containing bound mesons, like pions or eta mesons), the discovery of new neutron-rich isotopes, the search for new phenomena in weakly bound or dilute nuclear systems, and the search for neutron radioactivity, an elementary radioactive decay mode, which has not been discovered yet.
Scheidenberger, Christoph; Gales, Sydney; Geissel, Hans; Simon, Haik; Tanihata, Isao; Winkler, Martin
Folding peptides and proteins with all-atom physics: methods and applications
NASA Astrophysics Data System (ADS)
Computational methods offer powerful tools for investigating proteins and peptides at the molecular-level; however, it has proven challenging to reproduce the long time scale folding processes of these molecules at a level that is both faithful to the atomic driving forces and attainable with modern commodity cluster computing. Alternatively, the past decade has seen significant progress in using bioinformatics-based approaches to infer the three dimensional native structures of proteins, drawing upon extensive knowledge databases of known protein structures [1]. These methods work remarkably well when a homologous protein can be found to provide a structural template for a candidate sequence. However, in cases where homology to database proteins is low, where the folding pathway is of interest, or where conformational flexibility is substantial---as in many emerging protein and peptide technologies---bioinformatics methods perform poorly. There is therefore great interest in seeing purely physics-based approaches succeed. We discuss a purely physics-based, database-free folding method, relying on proper thermal sampling (replica exchange molecular dynamics) and molecular potential energy functions. In order to surmount the tremendous computational demands of all-atom folding simulations, our approach implements a conformational search strategy based on a putative protein folding mechanism called zipping and assembly [2-4]. That is, we explicitly seek out potential folding pathways inferred from short simulations, and iteratively pursue all such routes by coaxing a polypeptide chain along them. The method is called the Zipping and Assembly Method (ZAM) and it works in two parts: (1) the full polypeptide chain is broken into small fragments that are first simulated independently and then successively re-assembled into larger segments with further sampling, and (2) consistently stable structure in fragments is detected and locked into place, in order to avoid re-sampling those degrees of freedom in subsequent steps. ZAM pursues all potential folding routes it finds, which may be mutually exclusive, and it ranks these by calculating free energies along the way. Importantly, it gives full conformational ensembles and folding pathways, features not captured by bioinformatics approaches. We also discuss ways in which the structural ensembles and folding pathways of ZAM can facilitate the rational design of peptide technologies. In particular, we examine the coupling of ZAM-produced structures with coarse-grained theories of transport and association, in order to model the interactions of peptides with membranes (for insertion processes), proteins (for binding processes), and other peptides (for aggregation processes). Importantly, this approach is able to capture highly sequence-specific effects due to the atomistic nature of the ZAM folding simulations, providing a predictive tool for targeted sequence mutations. 1. J. Moult, A decade of CASP: progress, bottlenecks and prognosis in protein structure prediction, Curr. Opin. Struct. Biol. 15, (2005). 2. K.M. Fiebig and K.A. Dill, Protein core assembly processes, J. Chem. Phys. 98, (1993). 3. S.B. Ozkan, G.H.A. Wu, J.D. Chodera, and K.A. Dill, Protein folding by zipping and assembly, Proc. Natl. Acad. Sci. U. S. A. 104, (2007). 4. M.S. Shell, S.B. Ozkan, V.A. Voelz, G.H.A. Wu, and K. Dill, Can molecular physics predict the native structures of globular proteins?, under review, (2007).
Shell, M. Scott
Lithium Experiments in the NSTX Boundary Physics Program
The NSTX Program Plan calls for lithium experiments beginning with pellet injection, followed by lithium evaporation, and then operation with a Liquid Surface Module (LSM). Lithium pellet injection in FY04 will compare NSTX lithium results with the extensive TFTR lithium database. These experiments will be followed by higher yield film deposition techniques using a between-shot evaporator to coat the upper
H. W. Kugel; M. Bell; R. Kaita; R. Majeski; C. H. Skinner; V. Soukhanovskii; D. Stotler; R. Maingi; T. Rognlien; M. Ulrickson
The Social Experience of Physically Disabled Australian University Students
ERIC Educational Resources Information Center
Research on the university experience of disabled students has focused on barriers in learning and teaching, while the social world of university has as yet gained little attention as a distinctive object of study. Here we examine social experience and socially imposed restrictions through the lenses of social capital and self-concept. A�
Papasotiriou, Maria; Windle, Joel
Women's daily physical health symptoms and stressful experiences across adulthood
This study investigated the extent to which the experience of daily stressors was related to women's age and daily health symptomology, such as flu and cold symptoms. Respondents were 562 women (aged 25�74) who were a part of the National Study of Daily Experiences (NSDE), a telephone diary study examining daily stressful events. The respondents were interviewed by telephone on
Melanie Horn Mallers; David M. Almeida; Shevaun D. Neupert
Collider physics based on e-Science paradigm of experiment-computing-theory
NASA Astrophysics Data System (ADS)
Researches in the 21st century are characterized by e-Science paradigm, which is the data centric analysis as a unified concept of experiment-computing-theory. In this paper the e-Science paradigm has been realized in collider physics by constructing the unified research environment of experiment-theory and theory-computing as well as that of computing-experiment performed at KISTI (Korea Institute of Science and Technology Information). In other words, the fusion concept of collider physics of experiment, computing and theory has been applied. The goal of this approach is to study collider physics anytime, anywhere for more efficient research process. The construction of e-Science paradigm of experiment, computing and theory in collider physics provides us with new research methodology in computational physics.
Cho, Kihyeon; Kim, Junghyun; Nam, Soo-hyeon
Temperature and Final State Effects in Radio Frequency Spectroscopy Experiments on Atomic Fermi Gases
We present a simple and systematic characterization of the radio frequency (rf) spectra of homogeneous, paired atomic Fermi gases at general temperatures T in the presence of final-state interactions. The spectra, consisting of possible bound states and positive as well as negative detuning ({nu}) continua, satisfy exactly the zeroth- and first-moment sum rules at all T. We show how to best extract the pairing gap and how to detect the {nu}<0 continuum arising from thermally excited quasiparticles, not yet seen experimentally. We explain semiquantitatively recent rf experiments on 'bound-bound' transitions, predicting effects of varying temperature.
He Yan; Chien, C.-C.; Chen Qijin; Levin, K. [James Franck Institute and Department of Physics, University of Chicago, Chicago, Illinois 60637 (United States)
True Molecular-Scale Imaging in Atomic Force Microscopy: Experiment and Modeling
NASA Astrophysics Data System (ADS)
Imaging with molecular-resolution achieved in tapping mode atomic force microscopy (AFM) opened a number of questions concerning image contrast and its variations. These issues are addressed in the interplay between experiment and theory in studies of polydiacetylene crystal. The dependence of image features on tip force and tip size has been revealed in theoretical simulations where bifurcation phenomenon played a major role. Experimental observations of periodical surface structures with molecular-scale single defects do not necessary prove true molecular-scale resolution because a number of periodical features seen in AFM images can originate in a result of bifurcation.
Belikov, Sergey; Magonov, Sergei
Nondiffracting Optical Beams: Physical Properties, Experiments, and Applications
The controversial term �nondiffracting beam� was introduced into optics by Durnin in 1987. Discussions related to that term revived interest in problems of the light diffraction and resulted in an appearance of the new research direction of the classical optics, dealing with the localized transfer of electromagnetic energy. In this paper, the physical concept of the nondiffracting propagation is presented
Zdenek Bouchal
Source physics experiments at the Nevada Test Site
The U. S. capability to monitor foreign underground nuclear test activities relies heavily on measurement of explosion phenomena, including characteristic seismic, infrasound, radionuclide, and acoustic signals. Despite recent advances in each of these fields, empirical, rather than physics-based, approaches are used to predict and explain observations. Seismologists rely on prior knowledge of the variations of teleseismic and regional seismic parameters
Ping Lee; Catherine Snelson; Robert Abbott; David D. Coblentz; Robert Corbell; Theodore W. Bowyer; Aviva J. Sussman; Charles R. Carrigan; Christopher R. Bradley; Howard J. Patton; Carolyn E. Seifert; Jerry J. Sweeney; Wendee M. Brunish; Ward L. Hawkins; Tarabay H. Antoun; Kenneth H. Wohletz; John Jay Zucca
Russian Space Program: Experiments in Solar-Terrestrial Physics
We present a brief review of scientific milestones of the Russian Space Research Program for 2006-2015 in the field of solar and solar-terrestrial physics and describe several space projects: CORONAS-PHOTON, RESONANCE, CLIPPER, INTERHELIOPROBE, and THERION-F2.
L. M. Zelenyi; V. D. Kuznetsov; Yu. D. Kotov; A. A. Petrukovich; M. M. Mogilevsky; K. A. Boyarchuk; G. N. Zastenker; Yu. I. Yermolaev
Analytical Study of the Atmospheric Cloud Physics Laboratory (Acpl) Experiments.
National Technical Information Service (NTIS)
The design specifications of the research laboratory as a Spacelab facility are discussed along with the types of planned experiments. These include cloud formation, freezing and scavenging, and electrical phenomena. A summary of the program conferences i...
M. H. Davis
The Heat Capacity of Metals: A Physical Chemistry Experiment.
ERIC Educational Resources Information Center
Presented here are improvements in the original design of an introductory statistical thermodynamics experiment with the result that heat capacities of metals are routinely obtained within ten percent of literature values. (BB)
Shigeishi, R. A.
The use of cylindrical lenses in easy experiments for physics education and the magic arts
NASA Astrophysics Data System (ADS)
The purpose of this article is to present the properties of cylindrical lenses and provide some examples of their use in easy school physics experiments. Such experiments could be successfully conducted in the context of science education, in fun experiments that teach physics and in science fair projects, or used to entertain an audience by staging tricks, effects or illusions of seemingly impossible or supernatural feats.
Bednarek, Stanis?aw; Krysiak, Jerzy
Effect of Calcium and Magnesium on Phosphatidylserine Membranes: Experiments and All-Atomic Simulations
It is known that phosphatidylserine (PS?) lipids have a very similar affinity for Ca2+ and Mg2+ cations, as revealed by electrokinetic and stability experiments. However, despite this similar affinity, experimental evidence shows that the presence of Ca2+ or Mg2+ induces very different aggregation behavior for PS? liposomes as characterized by their fractal dimensions. Also, turbidity measurements confirm substantial differences in aggregation behavior depending on the presence of Ca2+ or Mg2+ cations. These puzzling results suggest that although these two cations have a similar affinity for PS? lipids, they induce substantial structural differences in lipid bilayers containing each of these cations. In other words, these cations have strong ion-specific effects on the structure of PS? membranes. This interpretation is supported by all-atomic molecular-dynamics simulations showing that Ca2+ and Mg2+ cations have different binding sites and induce different membrane hydration. We show that although both ions are incorporated deep into the hydrophilic region of the membrane, they have different positions and configurations at the membrane. Absorbed Ca2+ cations present a peak at a distance ?2�nm from the center of the lipid bilayer, and their most probable binding configuration involves two oxygen atoms from each of the charged moieties of the PS molecule (phosphate and carboxyl groups). In contrast, the distribution of absorbed Mg2+ cations has two different peaks, located a few angstroms before and after the Ca2+ peak. The most probable configurations (corresponding to these two peaks) involve binding to two oxygen atoms from carboxyl groups (the most superficial binding peak) or two oxygen atoms from phosphate groups (the most internal peak). Moreover, simulations also show differences in the hydration structure of the membrane: we obtained a hydration of 7.5 and 9 water molecules per lipid in simulations with Ca2+ and Mg2+, respectively.
Martin-Molina, Alberto; Rodriguez-Beas, Cesar; Faraudo, Jordi
An open source/real-time atomic force microscope architecture to perform customizable force spectroscopy experiments
NASA Astrophysics Data System (ADS)
We describe the realization of an atomic force microscope architecture designed to perform customizable experiments in a flexible and automatic way. Novel technological contributions are given by the software implementation platform (RTAI-LINUX), which is free and open source, and from a functional point of view, by the implementation of hard real-time control algorithms. Some other technical solutions such as a new way to estimate the optical lever constant are described as well. The adoption of this architecture provides many degrees of freedom in the device behavior and, furthermore, allows one to obtain a flexible experimental instrument at a relatively low cost. In particular, we show how such a system has been employed to obtain measures in sophisticated single-molecule force spectroscopy experiments [Fernandez and Li, Science 303, 1674 (2004)]. Experimental results on proteins already studied using the same methodologies are provided in order to show the reliability of the measure system.
Materassi, Donatello; Baschieri, Paolo; Tiribilli, Bruno; Zuccheri, Giampaolo; Samor�, Bruno
Solid Hydrogen Experiments for Atomic Propellants: Particle Formation, Imaging, Observations, and Analyses
NASA Technical Reports Server (NTRS)
This report presents particle formation observations and detailed analyses of the images from experiments that were conducted on the formation of solid hydrogen particles in liquid helium. Hydrogen was frozen into particles in liquid helium, and observed with a video camera. The solid hydrogen particle sizes and the total mass of hydrogen particles were estimated. These newly analyzed data are from the test series held on February 28, 2001. Particle sizes from previous testing in 1999 and the testing in 2001 were similar. Though the 2001 testing created similar particles sizes, many new particle formation phenomena were observed: microparticles and delayed particle formation. These experiment image analyses are some of the first steps toward visually characterizing these particles, and they allow designers to understand what issues must be addressed in atomic propellant feed system designs for future aerospace vehicles.
Palaszewski, Bryan
Solid Hydrogen Experiments for Atomic Propellants: Particle Formation Energy and Imaging Analyses
NASA Technical Reports Server (NTRS)
This paper presents particle formation energy balances and detailed analyses of the images from experiments that were conducted on the formation of solid hydrogen particles in liquid helium during the Phase II testing in 2001. Solid particles of hydrogen were frozen in liquid helium and observed with a video camera. The solid hydrogen particle sizes and the total mass of hydrogen particles were estimated. The particle formation efficiency is also estimated. Particle sizes from the Phase I testing in 1999 and the Phase II testing in 2001 were similar. Though the 2001 testing created similar particles sizes, many new particle formation phenomena were observed. These experiment image analyses are one of the first steps toward visually characterizing these particles and it allows designers to understand what issues must be addressed in atomic propellant feed system designs for future aerospace vehicles.
Palaszewski, Bryan
Penning traps as a versatile tool for precise experiments in fundamental physics
This review article describes the trapping of charged particles. The main principles of electromagnetic confinement of various species from elementary particles to heavy atoms are briefly described. The preparation and manipulation with trapped single particles, as well as methods of frequency measurements, providing unprecedented precision, are discussed. Unique applications of Penning traps in fundamental physics are presented. Ultra-precise trap-measurements of
K. Blaum; Yu. N. Novikov; G. Werth
Mini-Column Ion-Exchange Separation and Atomic Absorption Quantitation of Nickel, Cobalt, and Iron: An Undergraduate Quantitative Analysis Experiment.
ERIC Educational Resources Information Center
Presents an undergraduate quantitative analysis experiment, describing an atomic absorption quantitation scheme that is fast, sensitive and comparatively simple relative to other titration experiments. (CS)
Anderson, James L.; And Others
The US heavy ion fusion science program has developed techniques for heating ion-beam-driven warm dense matter (WDM) targets. The WDM conditions are to be achieved by combined longitudinal and transverse space-charge neutralized drift compression of the ion beam to provide a hot spot on the target with a beam spot size of about 1 mm, and pulse length about 1-2 ns. As a technique for heating volumetric samples of matter to high energy density, intense beams of heavy ions are capable of delivering precise and uniform beam energy deposition dE/dx, in a relatively large sample size, and the ability to heat any solid-phase target material. Initial experiments use a 0.3 MeV K+ beam (below the Bragg peak) from the NDCX-I accelerator. Future plans include target experiments using the NDCX-II accelerator, which is designed to heat targets at the Bragg peak using a 3-6 MeV lithium ion beam. The range of the beams in solid matter targets is about 1 micron, which can be lengthened by using porous targets at reduced density. We have completed the fabrication of a new experimental target chamber facility for WDM experiments, and implemented initial target diagnostics to be used for the first target experiments in NDCX-1. The target chamber has been installed on the NDCX-I beamline. The target diagnostics include a fast multi-channel optical pyrometer, optical streak camera, VISAR, and high-speed gated cameras. Initial WDM experiments will heat targets by compressed NDCX-I beams and will explore measurement of temperature and other target parameters. Experiments are planned in areas such as dense electronegative targets, porous target homogenization and two-phase equation of state.
Henestroza, E.; Leitner, M.; Logan, B.G.; More, R.M.; Roy, P.K.; Ni, P.; Seidl, P.A.; Waldron, W.L.; Barnard, J.J.
The US heavy ion fusion science program has developed techniques for heating ion-beam-driven warm dense matter (WDM) targets. The WDM conditions are to be achieved by combined longitudinal and transverse space-charge neutralized drift compression of the ion beam to provide a hot spot on the target with a beam spot size of about 1 mm, and pulse length about 1-2 ns. As a technique for heating volumetric samples of matter to high energy density, intense beams of heavy ions are capable of delivering precise and uniform beam energy deposition dE/dx, in a relatively large sample size, and the ability to heat any solid-phase target material. Initial experiments use a 0.3 MeV K+ beam (below the Bragg peak) from the NDCX-I accelerator. Future plans include target experiments using the NDCX-II accelerator, which is designed to heat targets at the Bragg peak using a 3-6 MeV lithium ion beam. The range of the beams in solid matter targets is about 1 micron, which can be lengthened by using porous targets at reduced density. We have completed the fabrication of a new experimental target chamber facility for WDM experiments, and implemented initial target diagnostics to be used for the first target experiments in NDCX-1. The target chamber has been installed on the NDCX-I beamline. The target diagnostics include a fast multi-channel optical pyrometer, optical streak camera, VISAR, and high-speed gated cameras. Initial WDM experiments will heat targets by compressed NDCX-I beams and will explore measurement of temperature and other target parameters. Experiments are planned in areas such as dense electronegative targets, porous target homogenization and two-phase equation of state.
Bieniosek, F.M.; Henestroza, E.; Leitner, M.; Logan, B.G.; More, R.M.; Roy, P.K.; Ni, P.; Seidl, P.A.; Waldron, W.L.; Barnard, J.J.
The STAR experiment at RHIC is a TPC-based, general purpose detector designed to obtain charged particle spectra, with an emphasis on hadrons over a large phase space. An electromagnetic calorimeter provides measurement of e's, {gamma}'s, {pi}{sup 0}'s and jets. Data-taking with Au + Au collisions at {radical}5 = 200 GeV/c{sup 2} begins in Fall 1999. The STAR experiment's investigation of techniques and signals using hard probes to study the high energy-density matter at RHIC and to search for quark-gluon plasma formation will be described.
Physics study of the TRADE : TRIGA accelerator driven experiment.
This report deals with the validation of an ADS dynamic behavior through the TRADE program. We first describe the motivations behind the TRADE project. This includes the types of ADS experiments to be performed and their necessity, beam trips issues, representativity of the experiment, and steps to be taken in the validation procedure. Then we perform the characterization of the TRADE core using deterministic methods. The general core description is given. A number of results related to the core criticality and modeling with different geometries are presented. Finally we report the experimental results of the recent critical measurements including the control rod calibration, determination of the critical configurations and fluxes in the core.
Naberejnev, D.; Imel, G.; Palmiotti, G.; Salvatores, M.
Phase Equilibrium, Chemical Equilibrium, and a Test of the Third Law: Experiments for Physical Chemistry.
ERIC Educational Resources Information Center
Described is an experiment designed to provide an experimental basis for a unifying point of view (utilizing theoretical framework and chemistry laboratory experiments) for physical chemistry students. Three experiments are described: phase equilibrium, chemical equilibrium, and a test of the third law of thermodynamics. (Author/DS)
Dannhauser, Walter
A Take-Home Physics Experiment Kit for On-Campus and Off-Campus Students
ERIC Educational Resources Information Center
A take-home experiment kit has been developed to reinforce the concepts in a first year physics course that both on and off campus students from a variety of educational backgrounds can successfully use. The kit is inexpensive and is composed of easy to obtain items. The experiments conducted with the kit are directed experiments that require�
Turner, Joanna; Parisi, Alfio
A Physics Exploratory Experiment on Plasma Liner Formation
Momentum flux for imploding a target plasma in magnetized target fusion (MTF) may be delivered by an array of plasma guns launching plasma jets that would merge to form an imploding plasma shell (liner). In this paper, we examine what would be a worthwhile experiment to explore the dynamics of merging plasma jets to form a plasma liner as a
Y. C. Francis Thio; Charles E. Knapp; Ronald C. Kirkpatrick; Richard E. Siemon; Peter J. Turchi
Skylab Experiments, Volume 5, Astronomy and Space Physics.
ERIC Educational Resources Information Center
Basic knowledge about Skylab experiments is presented in this book, one of a series, for the purpose of informing high school teachers about scientific research performed in orbit and enabling the teachers to broaden their basis for material selection. This fifth volume is concerned with studies of our own and other galaxies and effects of solar�
National Aeronautics and Space Administration, Washington, DC.
Experiments in Molecular Physics with an Acoustic Interferometer
ERIC Educational Resources Information Center
A device which provides an inexpensive means for making precise studies of the kinetics of gas molecules is discussed. Two experiments are described: (1) Measurement of the vibrational relaxation time of gas molecules and (2) determination of intermolecular forces in molecules. (Author/DF)
Rossing, Thomas D.
Robotic assist devices for bimanual physical therapy: preliminary experiments
Preliminary experiments were performed on a dynamically simplified system consisting of two outstretched hands constrained to flexion\\/extension while holding an object. A prototype device was designed to measure and assist in a transport task, in which the two hands moved a pencil-like object rhythmically back and forth, and in a bimanual squeezing task, in which the two hands squeezed the
Peter S. Lum; David J. Reinkensmeyer; Steven L. Lehman
The Design of Learning Experiences: A Connection to Physical Environments.
ERIC Educational Resources Information Center
The school environment must create a rich, beautiful, dynamic, meaningful experience for students to learn; however, architects, school boards, and the state focus almost exclusively only on the building when making design decisions. This document lists specific aspects to developing a visionary campus: one that provides a three-dimensional�
Stueck, Lawrence E.; Tanner, C. Kenneth
Cation Hydration Constants by Proton NMR: A Physical Chemistry Experiment.
ERIC Educational Resources Information Center
Studies the polarization effect on water by cations and anions. Describes an experiment to illustrate the polarization effect of sodium, lithium, calcium, and strontium ions on the water molecule in the hydration spheres of the ions. Analysis is performed by proton NMR. (MVL)
Smith, Robert L.; And Others
Physics prospects of the KTeV experiment at Fermilab.
National Technical Information Service (NTIS)
KTeV is a new Fermilab fixed target experiment which will search for direct CP violation in the neutral kaon system. In addition, we will make precision measurements of other CP and CPT violating parameters and make high sensitivity studies of rare kaon d...
J. Whitmore
Data management for high energy physics experiments: Preliminary proposals
Currently HEP experimental data are reduced as they become available. We propose instead a ''demand driven'' approach to data analysis. Full analysis will be performed only as needed, in response to user queries which specify the subset of events for which reduced data is needed. To support this approach we propose to partition the datasets on the cross product of several trigger inputs, instead of storing the data in chronological order. Queries will be automatically decomposed into a set of requests against several partitions. Indexing, physically clustering the data on the logical partitions, and caching of partitions will be employed for efficiency.
Olken, F.; Loken, S.C.; Rotem, D.; Shoshani, A.; Trippe, T.G.
Atomic-Scale Investigation of Latent Fission Tracks in Fluorapatite: Physical Characteristics and Annealing Behavior.
NASA Astrophysics Data System (ADS)
A JEOL JEM-2000FX analytical transmission electron microscope, equipped with a cold stage and anticontamination device, has been used to study the physical characteristics and annealing behavior of artificially induced fission tracks in fluorapatite. Near the atomic level, unetched fission tracks are not continuous, but are comprised of segments of extended damage that are separated by gaps of undamaged microstructure. From dark-field transmission electron microscopy (TEM) images, it appears that the crystalline damage around tracks, although intensive, is not extensive. As such, the defect density may be represented by a Gaussian-type distribution function. The disordered nature of the track core and defect distribution geometry supports the Ion-Explosion Theory that has been proposed for track formation. TEM analysis reveals that track width is crystallographically controlled. Parallel to the c-axis, tracks display widths of 5 to 13 nm and hexagonal faceting on the (0001) plane. Tracks perpendicular to the c-axis display widths of 3 to 9 nm and prismatic faceting on the (1000) plane. The track cross-section facets mimic etch-pit morphologies and provide a relative measure of the crystal's surface free energy. A consequence of differential bond strengths and elastic properties in the fluorapatite structure, track-width anisotropy resolves etching- and annealing-rate anisotropy that has been reported for fission tracks in fluorapatite. TEM observation of the behavior of fission tracks in response to electron beam exposure (i.e., radiolytic annealing), and temperature increase (i.e., thermal annealing), yields a physical and a kinetic description of the annealing process. Annealing commences with bulging at the track's tapered ends, followed by detachment of a single sphere. This process is replicated until a critical track radius is encountered at which the track geometry approaches an ideal right cylinder. A sinusoidal boundary develops at the track-matrix interface and increases in amplitude until the track spontaneously collapses into a row of spheres and small rods. The rods continue to evolve into spheres until the track remnant is comprised solely of a row of spheres. Although the spheres possess a stable surface energy geometry, ultimately they are restored to the original microstructure and the track disappears. Documentation of annealing suggests that the process is analogous to that of drop detachment, ovulation, and spheroidization. From these better known processes, it is possible to formulate a kinetic equation that describes fission-track annealing. Unlike the empirically-derived or physically-based kinetic equations that are presently employed in the reconstruction of thermo -tectonic histories from apatite fission-track data, the equation proposed in this study accurately predicts fission -track behavior over all of the scales of interest (i.e., microscopic to macroscopic dimensions, high to low temperatures, laboratory to geologic timescales). Furthermore, the equation reveals that surface interface diffusion is the primary mass transport mechanism that controls fission-track annealing.
Paul, Tracy Anne
A Comment On The Results Of Thermal Neutrons And Atomic Interferometers Experiments
NASA Astrophysics Data System (ADS)
There is a phenomenon with the real discrepancy between the used theory (Newtonian Gravity) and the measurements of the COW-experiment. This experiment measures the phase difference between two beams of thermal neutrons due to the effect of the Earth's gravitational field, provided that one of them is more closer to the Earth's surface than the other. In the third version of this experiment, the measurements of the phase shift; due to the Earth's gravitational field; show that the experimental results are lower than the theoretical calculations; based on Newtonian mechanics; by about 8 (10-3). This discrepancy has no interpretation so far. There are two possibilities to find a feasable interpretation for such discrepancy; either 1. it is due to the experimental artifact, or 2. it is related to the basis of the used theory (Newtonian gravity). The first possibility was and is still explored by several authors during 1991 and 1994. The outcome of these investigations shows that the experimental results may be higher than the theoretical calculations by about 3.7 (10-3). However, this study provides another discrepancy and it is not a conclusive one yet. Recently, during 1997 the same experiment with an anti-symmetric interferometer, was performed and the same discrepancy was found. Therefore, there is still a room to explore the second possibility. Such type of discrepancy is not present in the atomic interferometers. This discrepancy in thermal neurons interferometers may be used as an evidence for a possible existence of spin- gravity interactions.
Melek, M.
Atoms and Molecules. Physical Science in Action[TM]. Schlessinger Science Library. [Videotape].
ERIC Educational Resources Information Center
There are more than 20 million known substances in the universe, and they are all made of the same basic ingredients--atoms and molecules. In this fun and engaging program, kids will learn about the three main subatomic particles--protons, neutrons and electrons--as well as the forces that keep atoms and molecules together. They'll discover how�
Experimenting with the virtual environment Moodle in Physics Education
NASA Astrophysics Data System (ADS)
The master's program in Physics Education of the Catholic University in the state of Minas Gerais, Brazil, includes the discipline ``Digital technologies in Physics education.'' The main goal of this discipline is to discuss the role of Information and Communication Technology (ICT) in the process of learning-teaching science. We introduce our students to several virtual platforms, both free and commercial, discussing their functionality and features. We encourage our students to get in touch with computer tools and resources by planning their own computer based course using the Moodle platform. We discuss different patterns of virtual environment courses, whose proposals are centered mainly in the students, or teacher-centered or even system-centered. The student is free to choose between only one topic and a year course to work with, since their interests vary from learning something more about a specific subject to a complete e-learning course covering the entire school year. (The courses are available online in the address sitesinf01.pucmg.br/moodle. Participation only requires filling out an application form.) After three editions of this discipline, we have several courses available. We realize that students tend to focus on traditional methods, always preserving their role as knowledge-givers. In conclusion, we can say that, in spite of exhaustive discussion about autonomy involved with ICTs abilities, most of the students used the new virtual medium to organize traditional teacher-centered courses.
Martins, Maria Ines; Dickman, Adriana
Divertor plasma physics experiments on the DIII-D tokamak
In this paper we present an overview of the results and conclusions of our most recent divertor physics and development work. Using an array of new divertor diagnostics we have measured the plasma parameters over the entire divertor volume and gained new insights into several divertor physics issues. We present direct experimental evidence for momentum loss along the field lines, large heat convection, and copious volume recombination during detachment. These observations are supported by improved UEDGE modeling incorporating impurity radiation. We have demonstrated divertor exhaust enrichment of neon and argon by action of a forced scrape off layer (SOL) flow and demonstrated divertor pumping as a substitute for conventional wall conditioning. We have observed a divertor radiation zone with a parallel extent that is an order of magnitude larger than that estimated from a 1-D conduction limited model of plasma at coronal equilibrium. Using density profile control by divertor pumping and pellet injection we have attained H-mode confinement at densities above the Greenwald limit. Erosion rates of several candidate ITER plasma facing materials are measured and compared with predictions of a numerical model.
Mahdavi, M.A.; Allen, S.L.; Evans, T.E. [and others
Emulating Solid-State Physics with a Hybrid System of Ultracold Ions and Atoms
NASA Astrophysics Data System (ADS)
We propose and theoretically investigate a hybrid system composed of a crystal of trapped ions coupled to a cloud of ultracold fermions. The ions form a periodic lattice and induce a band structure in the atoms. This system combines the advantages of high fidelity operations and detection offered by trapped ion systems with ultracold atomic systems. It also features close analogies to natural solid-state systems, as the atomic degrees of freedom couple to phonons of the ion lattice, thereby emulating a solid-state system. Starting from the microscopic many-body Hamiltonian, we derive the low energy Hamiltonian, including the atomic band structure, and give an expression for the atom-phonon coupling. We discuss possible experimental implementations such as a Peierls-like transition into a period-doubled dimerized state.
Bissbort, U.; Cocks, D.; Negretti, A.; Idziaszek, Z.; Calarco, T.; Schmidt-Kaler, F.; Hofstetter, W.; Gerritsma, R.
Viscosity experiments: physical controls and implications for volcanic hazards
NSDL National Science Digital Library
Teaching students about viscosity is easy, effective and fun. It is a topic that is conducive to a range of teaching and learning styles, and allows for the integration of theory, experiments, and calculations. During the course of this exercise, students are required to make predictions about the outcomes of experiments, quantitatively document the results of their experiments, calculate viscosities using the Jeffreys equation (Jeffreys 1925; Nichols 1939; Cas and Wright 1987), and extrapolate the concepts learned from their laboratory results to natural conditions appropriate for silicate magmas and lavas. Students are also introduced to Ken Wohletz's freeware program MAGMA (no longer available), which allows them to determine viscosities for magma and lava compositions, and are required to do some simple graphical analysis of the effects of composition, dissolved H2O, and % solids on magma and lava viscosity using the MAGMA calculations. Viscosity is important for students at all levels of earth science to understand because it is a critical control on morphologies of volcanoes, velocities of lava flows, eruptive styles (effusive versus explosive), and ascent velocities of magmas within the earth. The objectives of the lab are for students to: learn about the rheological property called viscosity and some of the factors that affect it; think about and discuss ways in which viscosity controls styles of eruptions and relates to volcanic hazards; and practice quantitative skills. I have used the viscosity experiments as a classroom demonstration in introductory geology courses, as one part of a more extensive lab on volcanoes in introductory geology courses, and as a more intensive viscosity lab for introductory petrology courses. Generally the students do this exercise after they have had at least one introductory lecture on volcanoes, so that they are familiar with several basic terms, including viscosity, lava, magma, as well as some basic igneous rock terms (basalt, andesite, rhyolite). Over the fives years that I have been using the experiments, students at all levels have commented that the experiments are some of the most memorable, interesting and fun parts of my courses. I would welcome any direct student or instructor feedback for improvements or additions to the exercises (edwardsb AT dickinson.edu).
Edwards, Ben
Diagnostics for ion beam driven high energy density physics experiments
Intense beams of heavy ions are capable of heating volumetric samples of matter to high energy density. Experiments are performed on the resulting warm dense matter (WDM) at the NDCX-I ion beam accelerator. The 0.3 MeV, 30 mA K{sup +} beam from NDCX-I heats foil targets by combined longitudinal and transverse neutralized drift compression of the ion beam. Both the compressed and uncompressed parts of the NDCX-I beam heat targets. The exotic state of matter (WDM) in these experiments requires specialized diagnostic techniques. We have developed a target chamber and fielded target diagnostics including a fast multichannel optical pyrometer, optical streak camera, laser Doppler-shift interferometer (Velocity Interferometer System for Any Reflector), beam transmission diagnostics, and high-speed gated cameras. We also present plans and opportunities for diagnostic development and a new target chamber for NDCX-II.
Bieniosek, F. M.; Henestroza, E.; Lidia, S.; Ni, P. A. [Lawrence Berkeley National Laboratory, 1 Cyclotron Rd., Berkeley, California 94720 (United States)
Diagnostics for ion beam driven high energy density physics experiments.
Intense beams of heavy ions are capable of heating volumetric samples of matter to high energy density. Experiments are performed on the resulting warm dense matter (WDM) at the NDCX-I ion beam accelerator. The 0.3 MeV, 30 mA K(+) beam from NDCX-I heats foil targets by combined longitudinal and transverse neutralized drift compression of the ion beam. Both the compressed and uncompressed parts of the NDCX-I beam heat targets. The exotic state of matter (WDM) in these experiments requires specialized diagnostic techniques. We have developed a target chamber and fielded target diagnostics including a fast multichannel optical pyrometer, optical streak camera, laser Doppler-shift interferometer (Velocity Interferometer System for Any Reflector), beam transmission diagnostics, and high-speed gated cameras. We also present plans and opportunities for diagnostic development and a new target chamber for NDCX-II. PMID:21033977
Bieniosek, F M; Henestroza, E; Lidia, S; Ni, P A
Intense beams of heavy ions are capable of heating volumetric samples of matter to high energy density. Experiments are performed on the resulting warm dense matter (WDM) at the NDCX-I ion beam accelerator. The 0.3 MeV, 30-mA K{sup +} beam from NDCX-I heats foil targets by combined longitudinal and transverse neutralized drift compression of the ion beam. Both the compressed and uncompressed parts of the NDCX-I beam heat targets. The exotic state of matter (WDM) in these experiments requires specialized diagnostic techniques. We have developed a target chamber and fielded target diagnostics including a fast multi-channel optical pyrometer, optical streak camera, laser Doppler-shift interferometer (VISAR), beam transmission diagnostics, and high-speed gated cameras. We also present plans and opportunities for diagnostic development and a new target chamber for NDCX-II.
Bieniosek, F.M.; Henestroza, E.; Lidia, S.; Ni, P.A.
The TOTEM experiment at the LHC and its physics results
NASA Astrophysics Data System (ADS)
The TOTEM experiment at the LHC has measured proton-proton elastic scattering in dedicated runs at s=7and8TeV. The proton-proton total, elastic and inelastic cross-sections were derived with different methods by either using the optical theorem or a luminosity independent method, where the directly measured inelastic and elastic rates are applied. The TOTEM experiment presented its first preliminary cross-sections for soft single and double diffraction at s=7 TeV. The central diffraction analysis is ongoing, including a common TOTEM-CMS analysis. The charged particle pseudorapidity density distribution, dN/d?, was determined at 7 and 8 TeV.
Nemes, F.
The Telescope Array Experiment: An Overview and Physics Aims
The telescope Array (TA) experiment plans to deploy an array of 10 telescope stations in the west desert of Utah, USA and observes extremely high energy cosmic rays (EHECRs) by the atmospheric fluorescence. Its purpose is to study super-GZK (E > 1020 eV) cosmic rays discovered by AGASA. In order to identify the origin of super-GZK events, TA has �30
Y. Arai; J. Beltz; M. Chikawa; H. Fujii; M. Fukushima; K. Hashimoto; Y. Hatashi; N. Hayashida; K. Hibino; K. Honda; N. Inoue; C. Jui; K. Kadota; F. Kakimoto; K. Kasahara; H. Kawai; S. Kawakami; K. Martens; T. Matsuda; T. Nakamura; S. Ogio; M. Ohnishi; H. Ohoka; N. Sakurai; M. Sasano; S. Schnetzer; H. Shimodaira; P. Sokolsky; M. Takita; K. Tanaka; M. Tanaka; Y. Tanaka; M. Teshima; G. Thomson; R. Torii; S. Uchihori; N. Yasuda; S. Yoshida; H. Yoshii; T. Yoshikoshi
The EEE experiment project: status and first physics results
NASA Astrophysics Data System (ADS)
The Extreme Energy Events Project is an experiment for the detection of Extensive Air Showers which exploits the Multigap Resistive Plate Chamber technology. At the moment 40 EEE muon telescopes, distributed all over the Italian territory, are taking data, allowing the relative analysis to produce the first interesting results, which are reported here. Moreover, this Project has a strong added value thanks to its effectiveness in terms of scientific communication, which derives from the peculiar way it was planned and carried on.
Abbrescia, M.; Agocs, A.; Aiola, S.; Antolini, R.; Avanzini, C.; Baldini Ferroli, R.; Bencivenni, G.; Bossini, E.; Bressan, E.; Chiavassa, A.; Cical�, C.; Cifarelli, L.; Coccia, E.; De Gruttola, D.; De Pasquale, S.; Di Giovanni, A.; D'Incecco, M.; Dreucci, M.; Fabbri, F. L.; Frolov, V.; Garbini, M.; Gemme, G.; Gnesi, I.; Gustavino, C.; Hatzifotiadou, D.; La Rocca, P.; Li, S.; Librizzi, F.; Maggiora, A.; Massai, M.; Miozzi, S.; Panareo, M.; Paoletti, R.; Perasso, L.; Pilo, F.; Piragino, G.; Regano, A.; Riggi, F.; Righini, G. C.; Romano, F.; Sartorelli, G.; Scapparone, E.; Scribano, A.; Selvi, M.; Serci, S.; Siddi, E.; Spandre, G.; Squarcia, S.; Taiuti, M.; Toselli, F.; Votano, L.; Williams, M. C. S.; Y�nez, G.; Zichichi, A.; Zuyeuski, R.
Physical properties of powdered pineapple ( Ananas comosus) juice��effect of malt dextrin concentration and atomization speed
Using response surface methodology, whole industrialized pineapple juice with added malt dextrin was spray dried with an air inlet temperature of 190 �C and outlet temperature of 90 �C. The blower velocity was 25,000 rpm, feed rate 0.18 kg\\/min and variable atomization speed. The physical properties studied were: apparent and true density, color (a, b and L parameters), moisture content
F. D. B. Abadio; A. M. Domingues; S. V. Borges; V. M. Oliveira
Helicon Sources for High Beta Space Physics Experiments
NASA Astrophysics Data System (ADS)
The West Virginia University helicon source was constructed to provide plasma for experiments designed to investigate naturally occurring magnetospheric phenomena. The terrestrial magnetosphere is a collisionless, high beta plasma whose dynamics is heavily influenced by the action of kinetic instabilities, i.e., instabilities driven by non-Maxwellian particle distributions. For the past four years, we have been investigating electromagnetic instabilities driven by ion temperature anisotropy. The intrinsic ion heating that occurs in our helicon source [Scime et al., Plasma Sources Sci. and Technol. 7, 186-191, 1998] enables us to generate highly anisotropic plasmas. The plasma expands into a large, low magnetic field chamber where the instabilities develop and are studied. We will present a summary of our measurements of ion temperature anisotropy versus ion beta as well as our measurements of the characteristics of the observed electromagnetic fluctuations. The inverse scaling of ion temperature anisotropy with ion beta predicted by theory is observed in the experiment. Although the laboratory plasma is collisional, the collisional properties of the system were held constant and the inverse scaling of ion temperature anisotropy with ion beta was still observed. Throughout this presentation, we will emphasize how the unique capabilities of the WVU helicon source have enabled these experiments to be performed.
Scime, Earl; Boivin, Robert; Kline, John; Spangler, Robert; Sun, Xuan; Keiter, Paul; Balkey, Matthew
High energy physics experiment triggers and the trustworthiness of software
For all the time and frustration that high energy physicists expend interacting with computers, it is surprising that more attention is not paid to the critical role computers play in the science. With large, expensive colliding beam experiments now dependent on complex programs working at startup, questions of reliability -- the trustworthiness of software -- need to be addressed. This issue is most acute in triggers, used to select data to record -- and data to discard -- in the real time environment of an experiment. High level triggers are built on codes that now exceed 2 million source lines -- and for the first time experiments are truly dependent on them. This dependency will increase at the accelerators planned for the new millennium (SSC and LHC), where cost and other pressures will reduce tolerance for first run problems, and the high luminosities will make this on-line data selection essential. A sense of this incipient crisis motivated the unusual juxtaposition to topics in these lectures. 37 refs., 1 fig.
Nash, T.
Charm production physics from Fermilab fixed-target experiments
Recent analyses of charm quark production mechanisms from Fermilab fixed-target experiments are summarized. Measurements of single inclusive differential cross sections for hadroproduced and photoproduced D mesons are compared to next-to-leading order QCD calculations. New data from hadroproduction and previous photoproduction measurements of charm meson pair correlations are compared to NLO calculations and also to parton shower Monte Carlo models. Nonperturbative effects, such as intrinsic k{sub t} and fragmentation, are seen to play an important role in most of these comparisons. Results on charm production asymmetries in both hadroproduction and photoproduction are summarized.
Gardner, R. [Illinois Univ., Urbana, IL (United States). Dept. of Physics
Pixel multichip module design for a high energy physics experiment
At Fermilab, a pixel detector multichip module is being developed for the BTeV experiment. The module is composed of three layers. The lowest layer is formed by the readout integrated circuits (ICs). The back of the ICs is in thermal contact with the supporting structure, while the top is flip-chip bump-bonded to the pixel sensor. A low mass flex-circuit interconnect is glued on the top of this assembly, and the readout IC pads are wire-bounded to the circuit. This paper presents recent results on the development of a multichip module prototype and summarizes its performance characteristics.
Guilherme Cardoso et al.
Atomic-level structures and physical properties of magnetic CoSiB metallic glasses
NASA Astrophysics Data System (ADS)
Two CoSiB metallic glasses of low Co contents, which consist of different clusters, have recently been developed by addition of solute atoms. In this work, the atomic structure and the magnetic properties of the two CoBSi metallic glasses were elucidated by state-of-the-art extended X-ray absorption fine structure spectroscopy (EXAFS) combining with ab initio molecular-dynamics (AIMD) computational techniques. Besides, the origin of these magnetic behaviors was discussed in view of the EXAFS results and atomic structures of the metallic glasses.
Shan, Guangcun; Liang Zhang, Ji; Li, Jiong; Zhang, Shuo; Jiang, Zheng; Huang, Yuying; Shek, Chan-Hung
Casimir force experiments with quartz tuning forks and an atomic force microscope (AFM)
NASA Astrophysics Data System (ADS)
The aim of the measurement series is to study the Casimir force, specifically the effects of different materials and geometries. The art of measuring sub-nano Newton forces has been engineered to a great extent in the material sciences, especially for the atomic force microscope. In today's scanning microscope technologies there are several common methods used to measure sub-nano Newton forces. While the commercial atomic force microscopes (AFM) mostly work with soft silicon cantilevers, there are a large number of reports from university groups on the use of quartz tuning forks to get high resolution AFM pictures, to measure shear forces or to create new force sensors. The quartz tuning fork based force sensor has a number of advantages over the silicon cantilever, but also has some disadvantages. In this report the method based on quartz tuning forks is described with respect to their usability for Casimir force measurements and compared with other successful techniques. Furthermore, a design for Casimir force measurements that was set up in Berlin will be described and practical experimental aspects will be discussed. A status report on the Casimir experiments in Berlin will be given, including the experimental setup. In order to study the details of the Casimir effect the apparatus and active surfaces have to be improved further. The surfaces have to be flatter and cleaner. For better resolution, cantilevers and tuning forks with a low spring constant have to be employed.
Ludwig, T.
A Learning Pathway in High-School Level Quantum Atomic Physics.
ERIC Educational Resources Information Center
Describes one student's learning pathway as a sequence of several metastable conceptions of the atom starting from a planetary model. Displays the final cognitive element as an association of three parallel conceptions. Contains 26 references. (DDR)
Petri, Juergen; Niedderer, Hans
A learning pathway in high-school level quantum atomic physics
NSDL National Science Digital Library
Describes one student's learning pathway as a sequence of several metastable conceptions of the atom starting from a planetary model. Displays the final cognitive element as an association of three parallel conceptions. Contains 26 references.
Petri, Juergen; Niedderer, Hans
Highly excited Rydberg states of a rubidium atom: Theory versus experiments
NASA Astrophysics Data System (ADS)
There has been increasing interest in the energy spectrum of highly excited Rydberg states. The energy spectra of the s, p, and d highly excited Rydberg states of a rubidium atom have been measured by different groups. However, there is a discrepancy between the reported data concerning the energy levels of highly excited s and d states of Rb. We address this issue by performing accurate calculations of Rb(ns ,np,nd) energy levels using the parametric one-electron valence potential [Marinescu, Sadeghpour, and Dalgarno, Phys. Rev. A 49, 982 (1994), 10.1103/PhysRevA.49.982] with spin-orbit coupling. We compare results with reference data from the National Institute of Standards and Technology and from available experiments. This enables us to recommend energy levels of highly excited Rydberg states of Rb that can be used as reference values.
Pawlak, M.; Moiseyev, N.; Sadeghpour, H. R.
The physical mechanism of comet outbursts: an experiment
NASA Astrophysics Data System (ADS)
During a series of impact experiments into regolith-like powders at the NASA Ames Research Center Vertical Gun Facility in 1976, I observed and filmed a unique anomalous event that may illuminate outburst mechanisms in comets. During one test, a new batch of basalt powder (half the mass in particles less than 800 microns in diameter) retained some air pressure while the vacuum chamber was being evacuated. As a result, the projectile impacted into gas-charged regolith. Instead of ejecting the normal, relatively negligible amount of debris, the disturbance triggered a major eruption that lasted at least 18 seconds. The experimental results have been recently re-analyzed with reference to cometary phenomena. A series of frames from this eruption experiment are shown. The ejecta velocities of 150 to 300 cm/s would have been sufficient to drive debris into the coma of a comet nucleus smaller than a few kilometers diameter. The event suggests a mechanism for comet outbursts, discussed briefly by Hartmann et al.: the pore space in a layer of regolith, possibly with weak effective tensile strength, becomes gas charged as ice slowly sublimates. Once the effective tensile strength is exceeded by the gas pressure, the surface fails locally, triggering an eruption such as photographed here. This model is consistent with the emerging view of regolith materials on comets and is closest to the recent model of Rickman et al. The earlier models generally picture a more uniform flow of debris off the comet, not outbursts. Rickman et al. allow gas pressure to build until it matches the overburden pressure, followed by 'instantaneous blow-off'. They note that as soon as the mantle is found to be unstable, we consider it to be instantaneously swept away by the gas pressure. The main new points made here are that the experiment gives a more realistic view of the blow-off process after surface failure occurs, and the present model gives a recharge mechanism that can explain recurrent outbursts on comets such as P/Schwassmann-Wachmann 1 and 2060 Chiron. In fact, the resulting jets resemble distinct jet structures in high-resolution comet comae.
Hartmann, William K.
Physics of Colloids in Space: Microgravity Experiment Launched, Installed, and Activated on the International Space Station
NASA Technical Reports Server (NTRS)
The Physics of Colloids in Space (PCS) experiment is a Microgravity Fluids Physics investigation that is presently located in an Expedite the Process of Experiments to Space Station (EXPRESS) Rack on the International Space Station. PCS was launched to the International Space Station on April 19, 2001, activated on May 31, 2001, and will continue to operate about 90 hr per week through May 2002.
Doherty, Michael P.
Tokamak Physics Experiment safety analyses and enviromental safety, and health compliance activities
The Tokamak Physics Experiment (TPX) is a new fusion machine proposed to be built at the Princeton Plasma Physics Laboratory (PPPL). This paper describes results of the on-going safety analyses and Environmental, Safety, and Health (ES&H) activities in support of this project. The TPX deuterium and tritium operation perspectives, radiological design objectives, results of dose calculations for normal and postulated
C. G. Motloch; M. A. McKenzie-Carter; J. C. Commander; J. D. Levine
Fifth Grade Students' Experiences Participating in Active Gaming in Physical Education: The Persistence to Game
ERIC Educational Resources Information Center
Although video games are often associated with sedentary behaviors, active gaming is a new genre that requires children to become physically active while playing the games. In this study six fifth grade students' experiences participating in active gaming in eight-week physical education classes were explored. Qualitative methods of interviews,�
Hansen, Lisa; Sanders, Steve
Physical Restraint in Residential Childcare: The Experiences of Young People and Residential Workers
ERIC Educational Resources Information Center
There have long been concerns about the use of physical restraint in residential care. This article presents the findings of a qualitative study that explores the experiences of children, young people and residential workers of physical restraint. The research identifies the dilemmas and ambiguities for both staff and young people, and�
Steckley, Laura; Kendrick, Andrew
Digital Video: The Impact on Children's Learning Experiences in Primary Physical Education
ERIC Educational Resources Information Center
Technology can support teaching, learning and assessment in physical education. The purpose of this study was to examine children's perspectives and experiences of using digital video in primary physical education. The impact on motivation, feedback, self-assessment and learning was examined. Twenty-three children aged 9-10 years participated�
O'Loughlin, Joe; Chroinin, Deirdre Ni; O'Grady, David
FROM THE HISTORY OF PHYSICS: L D Landau in the Soviet Atomic Project: a documentary study
NASA Astrophysics Data System (ADS)
The article presents information about the participation of Academician L D Landau in the Soviet Atomic Project and is based on a study of archive documents of the First Main Directorate. Their analysis points to L D Landau's important contribution to the development of the theory of heterogeneous nuclear reactors and to the computational justification of the first designs of atomic and hydrogen bombs. Many of the quoted documents have never been published before.
Kiselev, G. V.
Nuclear physics experiments for the astrophysical p process
NASA Astrophysics Data System (ADS)
We studied the two astrophysically interesting reactions 141PrPm and 92MoTc with the activation method and with the in-beam method, respectively. The 141PrPm experiment was performed at the cyclotron of the �Physikalisch Technische Bundesanstalt (PTB)� in Braunschweig, Germany, and the reaction was studied within and just above the so-called Gamow window. In this proceedings, we present the experimental details of this measurement. The proton-capture reaction on the neutron-magic nucleus 92Mo was studied at energies relevant for the astrophysical p process. The reaction was investigated by the in-beam technique using the ?-ray detector array HORUS (High efficient Observatory for ?-Ray Unique Spectroscopy) at the TANDEM ion accelerator at the University of Cologne. The preliminary experimental results are compared to data stemming from other measurements.
Sauerwein, A.; Elvers, M.; Endres, J.; Hasper, J.; Hennig, A.; Netterdon, L.; Zilges, A.
Physics Results from the National Spherical Torus Experiment
The National Spherical Torus Experiment (NSTX) produces plasmas with aspect ratio A {triple_bond} R/a = 0.85m/0.68m {approx} 1.25, at plasma currents up to 1.5 MA with vacuum toroidal magnetic field up to 0.6 T on axis. The plasmas are heated by up to 6 MW of High-Harmonic Fast Waves (HHFW) at a frequency 30 MHz and by 7 MW of deuterium Neutral Beam Injection (NBI) at an energy up to 100 keV. Since January 2004, NSTX has been operating, routinely at toroidal fields up to 0.45 T, with a new central conductor bundle in the toroidal field coil.
M.G. Bell for the NSTX Research Team
Experiences with high dose radiopeptide therapy: The health physics perspective
One of the new, promising areas of nuclear medicine involves radiolabeled low-molecular-weight peptides for the diagnosis and management of cancer. Somatostatin analogous peptides bind to membrane receptors on tumors with high specificity. These analogues, when radiolabeled with I-123, I-131, Tc-99 m, or In-111, allow for external scintigraphic imaging or radioguided surgical resection of tumors. Somatostatin analogues with high tumor binding affinity have also been used for high-dose radiotherapy at the Medical Center of Louisiana since 1994. Although we had extensive prior experience with relatively high-dose I-131 administration for thyroid ablation, our personnel protection, contamination control, and other safety techniques required significant modification to ensure effective contamination and radiation exposure control. As therapy with radiolabeled peptides becomes more widely utilized, the controls developed at our institution may be implemented by others to maintain exposures ALARA.
Espenan, G D.; Nelson, J A.; Fisher, Darrell R. (BATTELLE (PACIFIC NW LAB)); Diaco, D S.; Mccarthy, K E. (Louisiana State University Medical Center, New Orl); Anthony, L B.; Maloney, T J. (Iso-Tex Diagnostics, Friendswood, TX); Woltering, E A.
A cryogenic tritium target system for nuclear physics experiments
NASA Astrophysics Data System (ADS)
A cryogenic tritium ( 3H 2) gas target system was constructed and used for a program of electron scattering studies. The 3H 2 was supplied and safely stored as solid U 3H 3. For the experiments, it was transferred to a thin walled cylindrical cell, where it was exposed to 25 ?A electron beams with energies up to 800 MeV. During operation, the target cell contained 115000 Ci of tritium at 225 psia and 45 K. Multiple safety enclosures surrounded both target and gas transfer systems. A microprocessor-based control and monitoring system presented target parameters to the operators, identifying those out of range. The target system operated safely and effectively for about 2000 h, enabling completion of comprehensive elastic and elastic electron scattering study of the three nucleon system.
Beck, D.; Retzlaff, G.; Turchinetz, W.; Blomqvist, K. I.; Demos, P.; Dodson, G.; Dow, K.; Dzengeleski, J.; Flanz, J.; Karageorge, G.; Masse, F.; Russ, T.; Russo, C.; Sapp, W.; Sargent, C. P.; Williamson, C.; Goloskie, R.; Farkhondeh, M.; Whitney, R.
Theoretical atomic collision physics. Progress report, July 1, 1991--June 30, 1992
The current focus of the research is low-energy (collision v<
Lane, N.F.
INSPIRE: Interactive NASA Space Physics Ionosphere Radio Experiment
NASA Astrophysics Data System (ADS)
The INSPIRE Project is a non-profit scientific and educational corporation whose objective is to bring the excitement of observing very low frequency (VLF) natural radio waves to high school students. Underlying this objective is the conviction that science and technology are the underpinnings of our modern society, and that only with an understanding of these disciplines can people make correct decisions in their lives. Since 1989, the INSPIRE Project has provided specially designed radio receiver kits to over 2,500 students and other groups to make observations of signals in the VLF frequency range. These kits provide an innovative and unique opportunity for students to actively gather data that can be used in a basic research project. Natural VLF emissions that can be studied with the INSPIRE receiver kits include sferics, tweeks, whistlers, and chorus, which originate from phenomena such as lightning. These emissions can either come from the local atmospheric environment within a few tens of kilometers of the receiver or from outer space thousands of kilometers from the Earth. VLF emissions are at such low frequencies that they can be received, amplified and turned into sound that we can hear, with each emission producing in a distinctive sound. In 2006 INSPIRE was re-branded and its mission has expanded to developing new partnerships with multiple science projects. Links to magnetospheric physics, astronomy, and meteorology are being identified. This presentation will introduce the INSPIRE project, display the INSPIRE receiver kits, show examples of the types of VLF emissions that can be collected and provide information on scholarship programs being offered.
Franzen, K. A.; Garcia, L. N.; Webb, P. A.; Green, J. L.
Advanced tokamak physics experiments on DIII-D
Significant reductions in the size and cost of a fusion power plant core can be realized if simultaneous improvements in the energy confinement time ({tau}{sub E}) and the plasma pressure (or beta {beta}{sub T} = 2 {mu}{sub 0} < p > /B{sub T}{sup 2}) can be achieved in steady-state conditions with high self driven bootstrap current fraction. In addition, effective power exhaust and impurity and particle control is required. Significant progress has been made in experimentally achieving regimes having the required performance in all of these aspects as well as in developing a theoretical understanding of the underlying physics. The authors have extended the duration of high performance ELMing H-mode plasmas with {beta}{sub N} H{sub iop} {approximately} 10 for 5 {tau}{sub E} ({approximately}1 s) and have demonstrated that core transport barriers can be sustained for the entire 5-s neutral beam duration in L-mode plasmas. Recent DIII-D work has advanced the understanding of improved confinement and internal transport barriers in terms of E x B shear stabilization of micro turbulence. With the aim of current profile control in discharges with negative central magnetic shear, they have demonstrated off-axis electron cyclotron current drive for the first time in a tokamak, finding an efficiency above theoretical expectations. MHD stability has been improved through shape optimization, wall stabilization, and modification of the pressure and current density profiles. Heat flux reduction and improved impurity and particle control have been realized through edge/divertor radiation and understanding and utilization of forced scrape off layer flow and divertor baffling.
Taylor, T.S. [General Atomics, San Diego, CA (United States)
Synthesis of atom probe experiments on irradiation-induced solute segregation in French ferritic pressure vessel steels
NASA Astrophysics Data System (ADS)
Microstructural changes due to neutron irradiation cause an evolution of the mechanical properties of reactor pressure vessels (RPV) steels. This paper aims at identifying and characterising the microstructural changes which have been found to be responsible in part for the observed embrittlement. This intensive work relies principally on an atom probe (AP) study of a low Cu-level French RPV steel (Chooz A). This material has been irradiated in in-service conditions for 0-16 years in the frame of the surveillance program. Under this aging condition, solute clustering occurs (Cu, Ni, Mn, Si, P, �). In order to identify the role of copper, experiments were also carried out on Fe-Cu model alloys submitted to different types of irradiations (neutron, electron, ion). Cu-cluster nucleation appears to be directly related to the presence of displacement cascades during neutron (ion) irradiation. The operating basic physical process is not clearly identified yet. A recovery of the mechanical properties of the irradiated material can be achieved by annealing treatments (20 h at 450�C in the case of the RPV steel under study, following microhardness measurements). It has been shown that the corresponding microstructural evolution was a rapid dissolution of the high number density of irradiation-induced solute clusters and the precipitation of a very low number density of Cu-rich particles.
Auger, P.; Pareige, P.; Welzel, S.; Van Duysen, J.-C.
Results from the Physics of Colloids Experiment on ISS
NASA Astrophysics Data System (ADS)
The PCS flight apparatus was accommodated in the ISS EXPRESS Rack 2 and was remotely operated from the NASA Glenn Research Center's (GRC) Telescience Support Center in Cleveland, Ohio and at a remote site at Harvard University in Cambridge, Massachusetts. This sophisticated light scattering instrument is capable of imaging, and dynamic and static (D&S) light scattering from 11 to 169 degrees, Bragg scattering over the range from 10 to 60 degrees, and laser light scattering at low angles from 0.3 to 6.0 degrees. PCS was launched on 4/19/2001 on Space Shuttle STS-100. The experiment was activated on May 31, 2001. As of February 2002, PCS has accomplished around 1800 hours of onboard operation, during which, binary colloidal crystal alloys, crystal nucleation and growth and the resultant structures have been studied. The long duration microgravity environment in the ISS facilitated extended studies on the growth and coarsening characteristics of crystals. The de-mixing of the colloid- polymer critical-point sample was also studied as it phase-separates into two phases, one that resembles a gas and one that resembles a liquid. This behavior cannot be observed in the sample on Earth because sedimentation would cause the colloids to fall to the bottom of the cell faster than the de-mixing process could occur. Similarly, the study of aging of another colloid-polymer sample, the colloid-polymer gel, also provided valuable information. The investigations on the extremely slow, low concentration fractal gels gave the initial gelation rate over several days. Several exciting and microgravity unique aspects of these results will be discussed.
Weitz, D. A.; Doherty, M.; Jankovsky, A.; Sankaran, S.; Lorik, T.; Shiley, W.; Bowen, J.; Kurta, C.; Eggers, J.; Bailey, A.; Manley, S.; Prasad, V.; Christianson, R.; Gasser, U.; Segre, P.; Cipelletti
Structural Isomer Identification via NMR: A Nuclear Magnetic Resonance Experiment for Organic, Analytical, or Physical Chemistry.
ERIC Educational Resources Information Center
Background information, procedures used, and typical results obtained are provided for an experiment that examines the ability of nuclear magnetic resonance (NMR) to distinguish between structural isomers via resonance multiplicities and chemical shifts. Reasons for incorporating the experiment into organic, analytical, or physical chemistry�
Szafran, Zvi
Teachers' Experience of School Based Examining (English and Physics). Examinations Bulletin No. 15.
ERIC Educational Resources Information Center
Teachers of fifth-grade English and physics courses in three schools conducted an experiment that focused on methods of assessment. The objects of the experiment were (1) to reveal problems which arise in making internal assessments, and (2) to search for and apply efficient, economical, and acceptable methods of assessment which might be of�
Schools Council, London (England).
Effects of Experimenting with Physical and Virtual Manipulatives on Students' Conceptual Understanding in Heat and Temperature
ERIC Educational Resources Information Center
This study aimed to investigate the comparative value of experimenting with physical manipulatives (PM) in a sequential combination with virtual manipulatives (VM), with the use of PM preceding the use of VM, and of experimenting with PM alone, with respect to changes in students' conceptual understanding in the domain of heat and temperature. A�
Zacharia, Zacharias C.; Olympiou, Georgios; Papaevripidou, Marios
Lived Employment Experiences of College Students and Graduates with Physical Disabilities in the United States
ERIC Educational Resources Information Center
This phenomenological study aims at understanding lived experiences of college seniors and recent college graduates with physical disabilities seeking employment opportunities after graduation in the USA The extensive interviews revealed that participants' attitudes about and experiences with disability are diverse (pain to pride, denied�
Kim, Mikyong Minsun; Williams, Brenda C.
Rich Experiences, Physical Activity Create Healthy Brains: An Interview with Developmental Psychologist William Greenough. Perspectives
ERIC Educational Resources Information Center
In this interview, Council member William Greenough discusses the need for rich, complex experiences combined with physical activity in early childhood to help build a strong foundation for learning. He explains how rich, complex experiences are necessary for the development of sound brain architecture, particularly during early childhood, but�
Ray, Marcy, Ed.
Using Student Peer Review of Experiment Reports in an Undergraduate Physics Class
ERIC Educational Resources Information Center
A class centered on student design of experiments and peer review of the resulting reports is described. Thirteen students in an honors seminar section of an introductory physics class designed experiments to test various types of paranormal phenomena. Each experimental report was evaluated and ranked by several other students. To give them�
Moran, Timothy; Van Hook, Stephen J.
The Experience of Choice in Physical Activity Contexts for Adults with Mobility Impairments
ERIC Educational Resources Information Center
This exploratory study described the experiences of choice in physical activity contexts for adults with mobility impairments. The experiences of 3 female and 2 males with mobility impairments between 18 and 23 years of age were described using the interpretive phenomenological methods of individual interviews, written stories, and field notes.�
Morphy, Lorraine Y.; Goodwin, Donna L.
RNA and Its Ionic Cloud: Solution Scattering Experiments and Atomically Detailed Simulations
RNA molecules play critical roles in many cellular processes. Traditionally viewed as genetic messengers, RNA molecules were recently discovered to have diverse functions related to gene regulation and expression. RNA also has great potential as a therapeutic and a tool for further investigation of gene regulation. Metal ions are an integral part of RNA structure and should be considered in any experimental or theoretical study of RNA. Here, we report a multidisciplinary approach that combines anomalous small-angle x-ray scattering and molecular-dynamics (MD) simulations with explicit solvent and ions around RNA. From experiment and simulation results, we find excellent agreement in the number and distribution of excess monovalent and divalent ions around a short RNA duplex. Although similar agreement can be obtained from a continuum description of the solvent and mobile ions (by solving the Poisson-Boltzmann equation and accounting for finite ion size), the use of MD is easily extended to flexible RNA systems with thermal fluctuations. Therefore, we also model a short RNA pseudoknot and find good agreement between the MD results and the experimentally derived solution structures. Surprisingly, both deviate from crystal structure predictions. These favorable comparisons of experiment and simulations encourage work on RNA in all-atom dynamic models.
Kirmizialtin, Serdal; Pabit, Suzette A.; Meisburger, Steve P.; Pollack, Lois; Elber, Ron
What do students learn about work in physical and virtual experiments with inclined planes?
NSDL National Science Digital Library
In previous studies, we have reported a difference in how physical and virtual manipulatives support students' understanding of the physics definition of work in the context of simple machines. We have shown that students who use the virtual manipulative (a computer simulation) before performing a physical experiment provided the correct response to multiple-choice questions about work more frequently than students who first use the physical manipulative. In this paper, we further analyze students' responses to a series of questions about work in the context of inclined planes to explore the models students used to answer the questions. While we had anticipated that students who performed the physical experiment would incorrectly respond to the multiple-choice questions in accordance with their observations (i.e. a longer ramp requires more work due to frictional effects), we actually observed these students more frequently using an alternate model that a longer ramp requires less work.
Chini, Jacquelyn J.; Madsen, Adrian M.; Rebello, N. S.; Puntambekar, Sadhana
Ground-Laboratory to In-Space Atomic Oxygen Correlation for the Polymer Erosion and Contamination Experiment (PEACE) Polymers
NASA Technical Reports Server (NTRS)
The Materials International Space Station Experiment 2 (MISSE 2) Polymer Erosion and Contamination Experiment (PEACE) polymers were exposed to the environment of low Earth orbit (LEO) for 3.95 years from 2001 to 2005. There were 41 different PEACE polymers, which were flown on the exterior of the International Space Station (ISS) in order to determine their atomic oxygen erosion yields. In LEO, atomic oxygen is an environmental durability threat, particularly for long duration mission exposures. Although spaceflight experiments, such as the MISSE 2 PEACE experiment, are ideal for determining LEO environmental durability of spacecraft materials, ground-laboratory testing is often relied upon for durability evaluation and prediction. Unfortunately, significant differences exist between LEO atomic oxygen exposure and atomic oxygen exposure in ground-laboratory facilities. These differences include variations in species, energies, thermal exposures and radiation exposures, all of which may result in different reactions and erosion rates. In an effort to improve the accuracy of ground-based durability testing, ground-laboratory to in-space atomic oxygen correlation experiments have been conducted. In these tests, the atomic oxygen erosion yields of the PEACE polymers were determined relative to Kapton H using a radio-frequency (RF) plasma asher (operated on air). The asher erosion yields were compared to the MISSE 2 PEACE erosion yields to determine the correlation between erosion rates in the two environments. This paper provides a summary of the MISSE 2 PEACE experiment; it reviews the specific polymers tested as well as the techniques used to determine erosion yield in the asher, and it provides a correlation between the space and ground laboratory erosion yield values. Using the PEACE polymers asher to in-space erosion yield ratios will allow more accurate in-space materials performance predictions to be made based on plasma asher durability evaluation.
Stambler, Arielle H.; Inoshita, Karen E.; Roberts, Lily M.; Barbagallo, Claire E.; deGroh, Kim K.; Banks, Bruce A.
Experiment and theory in particle physics: Reflections on the discovery of the tau lepton
This article is thoughts from the author on particle physics work from his perspective. It is not a summary of his work on the tau lepton, but rather a look at what makes good science, experimental and theoretical, from his experiences in the field. The section titles give a good summary on the topics the author chooses to touch upon. They are: the state of elementary particle physics; getting good ideas in experimental science; a difficult field; experiments and experimenting; 10% of the money and 30% of the time; the dictatorship of theory; technological dreams; last words.
Perl, M.L.
Physical pendulum�a simple experiment can give comprehensive information about a rigid body
NASA Astrophysics Data System (ADS)
A simple experiment with a physical pendulum examining some aspects of rigid body motion is presented in this paper. The experiment consists of measuring the period of oscillation of a rod with non-homogeneous mass distribution used as a physical pendulum, dependent upon the position of the pivot axis. The obtained dependence provides sufficient information to calculate the position of the centre of mass, moment of inertia of the rigid body and local gravitational acceleration. This experiment is intended for secondary school and undergraduate students.
Kladivov�, M�ria; Mucha, L'ubom�r
Microscope-Based Fluid Physics Experiments in the Fluids and Combustion Facility on ISS
NASA Technical Reports Server (NTRS)
At the NASA Glenn Research Center, the Microgravity Science Program is planning to conduct a large number of experiments on the International Space Station in both the Fluid Physics and Combustion Science disciplines, and is developing flight experiment hardware for use within the International Space Station's Fluids and Combustion Facility. Four fluids physics experiments that require an optical microscope will be sequentially conducted within a subrack payload to the Fluids Integrated Rack of the Fluids and Combustion Facility called the Light Microscopy Module, which will provide the containment, changeout, and diagnostic capabilities to perform the experiments. The Light Microscopy Module is planned as a fully remotely controllable on-orbit microscope facility, allowing flexible scheduling and control of experiments within International Space Station resources. This paper will focus on the four microscope-based experiments, specifically, their objectives and the sample cell and instrument hardware to accommodate their requirements.
Doherty, Michael P.; Motil, Susan M.; Snead, John H.; Malarik, Diane C.
Active experiments using rocket-borne shaped charge barium releases. [solar-terrestrial magnetospheric physics
NASA Technical Reports Server (NTRS)
A reliable payload system and scaled down shaped charges were developed for carrying out experiments in solar-terrestrial magnetospheric physics. Four Nike-Tomahawk flights with apogees near 450 km were conducted to investigate magnetospheric electric fields, and two Taurus-Tomahawk rockets were flown in experiments on the auroral acceleration process in discrete auroras. In addition, a radial shaped charge was designed for plasma perturbation experiments.
Wescott, E. M.; Davis, T. N.
The 2010 Interim Report of the Long-Baseline Neutrino Experiment Collaboration Physics Working Groups
In early 2010, the Long-Baseline Neutrino Experiment (LBNE) science collaboration initiated a study to investigate the physics potential of the experiment with a broad set of different beam, near- and far-detector configurations. Nine initial topics were identified as scientific areas that motivate construction of a long-baseline neutrino experiment with a very large far detector. We summarize the scientific justification for
T. Akiri; D. Allspach; M. Andrews; K. Arisaka; E. Arrieta-Diaz; M. Artuso; X. Bai; B. Balantekin; B. Baller; W. Barletta; G. Barr; M. Bass; A. Beck; B. Becker; V. Bellini; O. Benhar; B. Berger; M. Bergevin; E. Berman; H. Berns; A. Bernstein; F. Beroz; V. Bhatnagar; B. Bhuyan; R. Bionta; M. Bishai; A. Blake; E. Blaufuss; B. Bleakley; E. Blucher; S. Blusk; D. Boehnlein; T. Bolton; J. Brack; R. Bradford; R. Breedon; C. Bromberg; R. Brown; N. Buchanan; L. Camilleri; M. Campbell; R. Carr; G. Carminati; A. Chen; H. Chen; D. Cherdack; C. Chi; S. Childress; B. Choudhary; E. Church; D. Cline; S. Coleman; R. Corey; M. D'Agostino; G. Davies; S. Dazeley; J. De Jong; B. DeMaat; D. Demuth; A. Dighe; Z. Djurcic; J. Dolph; G. Drake; A. Drozhdin; H. Duan; H. Duyang; S. Dye; T. Dykhuis; D. Edmunds; S. Elliott; S. Enomoto; C. Escobar; J. Felde; F. Feyzi; B. Fleming; J. Fowler; W. Fox; A. Friedland; B. Fujikawa; H. Gallagher; G. Garilli; G. Garvey; V. Gehman; G. Geronimo; R. Gill; M. Goodman; J. Goon; D. Gorbunov; R. Gran; V. Guarino; E. Guarnaccia; R. Guenette; P. Gupta; A. Habig; R. Hackenberg; A. Hahn; R. Hahn; T. Haines; S. Hans; J. Harton; S. Hays; E. Hazen; Q. He; A. Heavey; K. Heeger; R. Hellauer; A. Himmel; G. Horton-Smith; J. Howell; P. Huber; P. Hurh; J. Huston; J. Hylen; J. Insler; D. Jaffe; C. James; C. Johnson; M. Johnson; R. Johnson; W. Johnson; W. Johnston; J. Johnstone; B. Jones; H. Jostlein; T. Junk; S. Junnarkar; R. Kadel; T. Kafka; D. Kaminski; G. Karagiorgi; A. Karle; J. Kaspar; T. Katori; B. Kayser; E. Kearns; S. Kettell; F. Khanam; J. Klein; J. Kneller; G. Koizumi; J. Kopp; S. Kopp; W. Kropp; V. Kudryavtsev; A. Kumar; J. Kumar; T. Kutter; T. Lackowski; K. Lande; K. Lang; F. Lanni; R. Lanza; T. Latorre; J. Learned; D. Lee; K. Lee; Y. Li; S. Linden; J. Ling; J. Link; L. Littenberg; L. Loiacono; T. Liu; J. Losecco; W. Louis; P. Lucas; C. Lunardini; B. Lundberg; T. Lundin; D. Makowiecki; S. Malys; S. Mandal; A. Mann; P. Mantsch; W. Marciano; C. Mariani; J. Maricic; A. Marino; M. Marshak; R. Maruyama; J. Mathews; S. Matsuno; C. Mauger; E. McCluskey; K. McDonald; K. McFarland; R. McKeown; R. McTaggart; R. Mehdiyev; W. Melnitchouk; Y. Meng; B. Mercurio; M. Messier; W. Metcalf; R. Milincic; W. Miller; G. Mills; S. Mishra; S. MoedSher; D. Mohapatra; N. Mokhov; C. Moore; J. Morfin; W. Morse; A. Moss; S. Mufson; J. Musser; D. Naples; J. Napolitano; M. Newcomer; B. Norris; S. Ouedraogo; B. Page; S. Pakvasa; J. Paley; V. Paolone; V. Papadimitriou; Z. Parsa; K. Partyka; Z. Pavlovic; C. Pearson; S. Perasso; R. Petti; R. Plunkett; C. Polly; S. Pordes; R. Potenza; A. Prakash; O. Prokofiev; X. Qian; J. Raaf; V. Radeka; R. Raghavan; R. Rameika; B. Rebel; S. Rescia; D. Reitzner; M. Richardson; K. Riesselman; M. Robinson; M. Rosen; C. Rosenfeld; R. Rucinski; T. Russo; S. Sahijpal; S. Salon; N. Samios; M. Sanchez; R. Schmitt; D. Schmitz; J. Schneps; K. Scholberg; S. Seibert; F. Sergiampietri; M. Shaevitz; P. Shanahan; M. Shaposhnikov; R. Sharma; N. Simos; V. Singh; G. Sinnis; W. Sippach; T. Skwarnicki; M. Smy; H. Sobel; M. Soderberg; J. Sondericker; W. Sondheim; J. Spitz; N. Spooner; M. Stancari; I. Stancu; J. Stewart; P. Stoler; J. Stone; S. Stone; J. Strait; T. Straszheim; S. Striganov; G. Sullivan; R. Svoboda; B. Szczerbinska; A. Szelc; R. Talaga; H. Tanaka; R. Tayloe; D. Taylor; J. Thomas; L. Thompson; M. Thomson; C. Thorn; X. Tian; W. Toki; N. Tolich; M. Tripathi; M. Trovato; H. Tseung; M. Tzanov; J. Urheim; S. Usman; M. Vagins; R. Van Berg; R. Van de Water; G. Varner; K. Vaziri; G. Velev; B. Viren; T. Wachala; C. Walter; H. Wang; Z. Wang; D. Warner; D. Webber; A. Weber; R. Wendell; C. Wendt; M. Wetstein; H. White; S. White; L. Whitehead; W. Willis; R. J. Wilson; L. Winslow; J. Ye; M. Yeh; B. Yu; G. Zeller; C. Zhang; E. Zimmerman; R. Zwaska
The physics of coal liquid slurry atomization. Final report to Department of Energy - PETC
The stability of turbulent columns of liquid injected into a quiescent environment was studied. Laser Doppler Anemometry measurements of the flow patterns and turbulence characteristics in free liquid jets were made. Turbulence decay along Newtonian jets was investigated along with the effects of turbulence on the resulting droplet size distributions after breakup. The rate of decay of turbulence properties along the jet were investigated. Disintegration of liquid jets injected into a high-velocity gas stream has also been studied. Newtonian and non-Newtonian liquids were studied with particular emphasis on the non-Newtonian rheological characteristics. Determination was made of the extent that the addition of high molecular weight polymer to liquids change the breakup process. Shear thinning, extension thinning and extension thickening fluids were investigated. Shear viscosities were measured over five decades of shear rates. The contraction flow technique was also used for measurement of the extensional viscosity of non-Newtonian liquids. The die-swell technique was also used to determine the first normal stress difference. The near field produced by a co-axial airblast atomizer was investigated using the phase Doppler particle analyzer. Whether or not the classical wave mechanism and empirical models reported for airblast atomization of low viscosity liquid are applicable to airblast atomization of viscous non-Newtonian liquids was determined. The theoretical basis of several models which give the best fit to the experimental data for airblast atomization of non-Newtonian liquids was also discussed. The accuracy of the wave mechanism-based models in predicting droplets sizes after breakup of viscous non-Newtonian liquids using an airblast atomizer has also been demonstrated.
Chigier, N.; Mansour, A.
LDEF atomic oxygen fluence update
NASA Technical Reports Server (NTRS)
The definition of LDEF atomic oxygen exposure involves theoretical prediction of fluxes, modeling of shielding and scattering effects, and comparison of predicted with observed atomic oxygen effects on LDEF experiments. Work is proceeding as follows: atomic oxygen fluxes and fluences have been recalculated using a more detailed orbit prediction program; a micro-environments program is being developed to account for the effects of experiment geometry on atomic oxygen flux; and chemical and physical measurements are being made on copper grounding straps to verify correspondence between predicted exposures and observed surface property variations. These three areas of work are reported briefly.
Bourassa, Roger J.; Gillis, J. R.
Experiments at the Triangle Universities Nuclear Laboratory for the undergraduate physics curriculum
Experiments are being developed at the Triangle Universities Nuclear Laboratory to offer advanced undergraduate physics students laboratory experiences in the atmosphere of a frontier accelerator facility. These experiments differ from projects done by Undergraduate Research Assistants in that they are designed specifically for integration into the undergraduate curriculum as part of a structured laboratory course. The immediate goal of the program is to develop four accelerator-based experiments for use in the undergraduate Advanced Laboratory course at Duke University. Two newly developed experiments, {ital Carbon-Carbon Mott Scattering} and {ital Lifetime Measurements of an Auger Emitter}, will be described. In addition, the logistics of conducting undergraduate laboratory course work in an active research facility will be discussed. {copyright} {ital 1999 American Institute of Physics.}
Howell, C.R. [Department of Physics, Duke University and the Triangle Universities Nuclear Laboratory, Durham, North Carolina 27708 (United States)