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Office of Scientific and Technical Information
Method for imaging with low frequency electromagnetic fields
DOE Patents (OSTI)
A method for imaging with low frequency electromagnetic fields, and for interpreting the electromagnetic data using ray tomography, in order to determine the earth conductivity with high accuracy and resolution. The imaging method includes the steps of placing one or more transmitters, at various positions in a plurality of transmitter holes, and placing a plurality of receivers in a plurality of receiver holes. The transmitters generate electromagnetic signals which diffuse through a medium, such as earth, toward the receivers. The measured diffusion field data H is then transformed into wavefield data U. The traveltimes corresponding to the wavefield data U, are then obtained, by charting the wavefield data U, using a different regularization parameter .alpha. for each transform. The desired property of the medium, such as conductivity, is then derived from the velocity, which in turn is constructed from the wavefield data U using ray tomography.
Lee, Ki H. (Lafayette, CA); Xie, Gan Q. (Berkeley, CA)
Program on Technology Innovation: Frequently Asked Questions (FAQ) on Radio-Frequency Electromagnetic Fields
Science Conference Proceedings (OSTI)
The number of sources of radio-frequency (RF) electromagnetic fields in our midst has increased dramatically in the past three decades.�From cordless phones, to cellular phones and their base stations, to pagers and walkie-talkies, to WiFi in public venues, such as coffee shops and airports, and to smart meters and other wireless components of the smart grid.�Of course, since the advent of broadcast radio and TV during the 20th century, radio-frequency electromagnetic fields have been an ...
Interaction of extremely-low-frequency electromagnetic fields with living systems
SciTech Connect
The sources and physical properties of extremely-low-frequency (ELF) electromagnetic fields are described in this paper. Biological effects and mechanisms through which ELF fields interact with humans and other organisms are discussed, including several aspects of this subject that are presently under active laboratory investigation. Studies on the potential health effects of ELF fields present in the home and workplace are also summarized, including a critical evaluation of evidence for a possible linkage between exposure to ELF fields and cancer risk. 53 refs.
Tenforde, T.S.
Determination of High-Frequency Current Distribution Using EMTP-Based Transmission Line Models with Resulting Radiated Electromagnetic Fields
Application of BPL technologies to existing overhead high-voltage power lines would benefit greatly from improved simulation tools capable of predicting performance - such as the electromagnetic fields radiated from such lines. Existing EMTP-based frequency-dependent line models are attractive since their parameters are derived from physical design dimensions which are easily obtained. However, to calculate the radiated electromagnetic fields, detailed current distributions need to be determined. This paper presents a method of using EMTP line models to determine the current distribution on the lines, as well as a technique for using these current distributions to determine the radiated electromagnetic fields.
Mork, B; Nelson, R; Kirkendall, B; Stenvig, N
The Study of Electromagnetic Field Response Using Very Low Frequency Methods in Geothermal Area, Sabang
Electromagnetic field measurements have been performed using the method of Very Low Frequency tilt angle pattern in Jaboi, Sabang. A site survey was conducted and carried out to identify the anomalies of location, depth and geometry of hydrothermal based on tilt angle measurement and ellipse. Objective of this study is to see the response of the magnetic and electric field in relation to location, depth and hydrothermal geometry. The devices of T-VLF-R IRIS was used in this study, while the (NWC) station was selected as main station and (JJF4) station was selected as comparison station. The electromagnetic field survey was recorded for a line spanned as long as 900 meters at the interval of 10 meter depth. The results of this study show the greatest anomaly occurred at line interval between 400-600 meters with a depth of 10-140 meters. Anomaly pattern of each depth shows that the propagation pattern of hydrothermal is in the form of vertical pipe flow.
Isa, M. [Departement of Physics Syiah Kuala University Banda Aceh, 23111 (Indonesia); School of Physics, Universiti Sains Malaysia 11800, Penang (Malaysia); Lim, H. S.; Jafri, M. Z. Mat [School of Physics, Universiti Sains Malaysia 11800, Penang (Malaysia)
Dangerous electromagnetic fields?
NLE Websites -- All DOE Office Websites (Extended Search)
Dangerous electromagnetic fields? Dangerous electromagnetic fields? Name: Tommy T Joseph Location: N/A Country: N/A Date: N/A Question: Why are electromagnetic fields supposedly dangerous? Replies: I assume you are asking about power line frequency (60 Hz) fields, since they have been in the news lately. No one knows for sure that they are dangerous. There have been a few studies which seem to show an association between how close homes are to power lines, and the incidence of childhood cancer (mostly leukemia) in children living (or who have lived) in those homes. Other similar studies have not found such an association. In all the studies which have found an association, none has actually measured the fields. Studies which actually have measured the fields find no association. There is no known mechanism for 60 Hz fields to cause cancer. Furthermore, the classic "dose-response relationship," that is, the greater the dose, the greater the response, does not seem to work here. Many laboratory studies have found that 60 Hz fields have an effect on organisms under certain conditions, but none of the observed effects can be convincingly related to a hazard. The bottom line is, no one knows for sure. It is important to realize that it is impossible to prove that anything is completely safe. My personal opinion is that, if there is a risk, it must be very small, or it wouldn't be so hard to prove. I can supply some good unbiased references if you are interested.
Definition: Frequency-Domain Electromagnetics Survey | Open Energy
Open Energy Info (EERE)
Frequency-Domain Electromagnetics Survey Frequency-Domain Electromagnetics Survey Jump to: navigation, search Dictionary.png Frequency-Domain Electromagnetics Survey Frequency-domain electromagnetic techniques are continuous wave field methods which enable the mapping of the electrical conductivity of the subsurface through electromagnetic induction.[1] View on Wikipedia Wikipedia Definition Electromagnetic induction is the production of a potential difference (voltage) across a conductor when it is exposed to a varying magnetic field. Michael Faraday is generally credited with the discovery of induction in 1831 though it may have been anticipated by the work of Francesco Zantedeschi in 1829. Around 1830 to 1832, Joseph Henry made a similar discovery, but did not publish his findings until later. Faraday's
Definition: Frequency-Domain Electromagnetic Survey | Open Energy
Electromagnetic Survey Electromagnetic Survey Jump to: navigation, search Dictionary.png Frequency-Domain Electromagnetic Survey Frequency-domain electromagnetic techniques are continuous wave field methods which enable the mapping of the electrical conductivity of the subsurface through electromagnetic induction.[1] Also Known As Controlled-Source EM References ↑ http://library.seg.org/doi/pdf/10.1190/1.1441531 Ret LikeLike UnlikeLike You like this.Sign Up to see what your friends like. rieved from "http://en.openei.org/w/index.php?title=Definition:Frequency-Domain_Electromagnetic_Survey&oldid=591411" Category: Definitions What links here Related changes Special pages Printable version Permanent link Browse properties About us Disclaimers Energy blogs Linked Data Developer services
Narrow field electromagnetic sensor system and method
A narrow field electromagnetic sensor system and method of sensing a characteristic of an object provide the capability to realize a characteristic of an object such as density, thickness, or presence, for any desired coordinate position on the object. One application is imaging. The sensor can also be used as an obstruction detector or an electronic trip wire with a narrow field without the disadvantages of impaired performance when exposed to dirt, snow, rain, or sunlight. The sensor employs a transmitter for transmitting a sequence of electromagnetic signals in response to a transmit timing signal, a receiver for sampling only the initial direct RF path of the electromagnetic signal while excluding all other electromagnetic signals in response to a receive timing signal, and a signal processor for processing the sampled direct RF path electromagnetic signal and providing an indication of the characteristic of an object. Usually, the electromagnetic signal is a short RF burst and the obstruction must provide a substantially complete eclipse of the direct RF path. By employing time-of-flight techniques, a timing circuit controls the receiver to sample only the initial direct RF path of the electromagnetic signal while not sampling indirect path electromagnetic signals. The sensor system also incorporates circuitry for ultra-wideband spread spectrum operation that reduces interference to and from other RF services while allowing co-location of multiple electronic sensors without the need for frequency assignments. 12 figs.
McEwan, T.E.
Electromagnetic fields in cased borehole
DOE Green Energy (OSTI)
Borehole electromagnetic (EM) measurements, using fiberglass-cased boreholes, have proven useful in oil field reservoir characterization and process monitoring (Wilt et al., 1995). It has been presumed that these measurements would be impossible in steel-cased wells due to the very large EM attenuation and phase shifts. Recent laboratory and field studies have indicated that detection of EM signals through steel casing should be possible at low frequencies, and that these data provide a reasonable conductivity image at a useful scale. Thus, we see an increased application of this technique to mature oilfields, and an immediate extension to geothermal industry as well. Along with the field experiments numerical model studies have been carried out for analyzing the effect of steel casing to the EM fields. The model used to be an infinitely long uniform casing embedded in a homogeneous whole space. Nevertheless, the results indicated that the formation signal could be accurately recovered if the casing characteristics were independently known (Becker et al., 1998; Lee el al., 1998). Real steel-cased wells are much more complex than the simple laboratory models used in work to date. The purpose of this study is to develop efficient numerical methods for analyzing EM fields in realistic settings, and to evaluate the potential application of EM technologies to cross-borehole and single-hole environment for reservoir characterization and monitoring.
Lee, Ki Ha; Kim, Hee Joon; Uchida, Toshihiro
Computer simulation of low-frequency electromagnetic data acquisition
Computer simulation of low frequency electromagnetic (LFEM) digital data acquisition in the presence of natural field noise demonstrates several important limitations and considerations. Without the use of a remote reference noise removal scheme it is difficult to obtain an adequate ratio of signal to noise below 0.1 Hz for frequency domain processing and below 0.3 Hz base frequency for time domain processing for a typical source-receiver configuration. A digital high-pass filter substantially facilitates rejection of natural field noise above these frequencies but, at lower frequencies where much longer stacking times are required, it becomes ineffective. Use of a remote reference to subtract natural field noise extends these low-frequency limits a decade, but this technique is limited by the resolution and dynamic range of the instrumentation. Gathering data in short segments so that natural field drift can be offset for each segment allows a higher gain setting to minimize dynamic range problems.
SanFilipo, W.A.; Hohmann, G.W.
Electromagnetic Lorenz Fields
E-Print Network (OSTI)
Gauge transformations are potential transformations that leave only specific Maxwell fields invariant. To reveal more, I develop Lorenz field equations with full Maxwell form for nongauge, sans gauge function, transformations yielding mixed, superposed retarded and outgoing, potentials. The form invariant Lorenz condition is then a charge conservation equivalent. This allows me to define three transformation classes that screen for Lorenz relevance. The nongauge Lorentz conditions add polarization fields which support emergent, light-like rays that convey energy on charge conserving phase points. These localized rays escape discovery in modern Maxwell fields where the polarizations are suppressed by gauge transformations.
H. C. Potter
A current concern. [Electromagnetic fields
This article examines the risk to homeowners of exposure to electromagnetic fields (EMF). Studies that link EMF to cancer are described and recommendations are given for prudent avoidance. Appliance manufacturers claim to have found no economically feasible way to shield emissions. Meanwhile the EPA's health effects research in this area has been suspended because of budgetary constraints.
Brinckerhoff, S.
The courts and electromagnetic fields
This article examines the recent development in eminent domain cases involving power transmission line rights of way, the issue of fear of the mythical buyer. The author feels that the fear of electrocution or of the possible cancer-inducing effects of electromagnetic fields is greatly influencing court decisions in these cases. The results could be more expensive rights of way acquisition by utilities.
Freeman, M. (Univ. of Pennsylvania, Philadelphia (United States))
Automatic collecting technique of low frequency electromagnetic signals and its application in earthquake study
Two methods to automatically collect disturbed ultra low frequency electromagnetic signals before strong earthquakes were developed in this paper, in which one is only related to the spectrum intensity of electric field, and another is additionally combined ... Keywords: Chile earthquake, DEMETER, fractal property, multi parameters, ultra low frequency electromagnetic emission
Xuemin Zhang; Roberto Battiston; Xuhui Shen; Zhima Zeren; Xinyan Ouyang; Jiadong Qian; Jing Liu; Jianping Huang; Yuanqing Miao
CRC handbook of biological effects of electromagnetic fields
This book presents the current knowledge about the effects of electromagnetic fields on living matter. The three-part format covers dielectric permittivity and electrical conductivity of biological materials; effects of direct current and low frequency fields; and effects of radio frequency (including microwave) fields. The parts are designed to be consulted independently or in sequence, depending upon the needs of the reader. Useful appendixes on measurement units and safety standards are also included.
Polk, C.; Postow, E.
This book presents current knowledge about the effects of electromagnetic fields on living matter. The three-part format covers: dielectric permittivity and electrical conductivity of biological materials; effects of direct current and low frequency fields; and effects of radio frequency (including microwave) fields. The parts are designed to be consulted independently or in sequence, depending upon the needs of the reader. Useful appendixes on measurement units and safety standards are also included.
Polk, C. (Rhode Island Univ., Kingston, RI (United States). Dept. of Electrical Engineering); Postow, E. (National Naval Medical Center, Bethesda, MD (United States))
Resonant circuit which provides dual-frequency excitation for rapid cycling of an electromagnet
Disclosed is a novel ring-magnet control circuit that permits synchrotron repetition rates much higher than the frequency of the sinusoidal guide field of the ring magnet during particle acceleration. The control circuit generates sinusoidal excitation currents of different frequencies in the half waves. During radio-frequency acceleration of the synchrotron, the control circuit operates with a lower frequency sine wave and, thereafter, the electromagnets are reset with a higher-frequency half sine wave.
Praeg, W.F.
Noninvasive valve monitor using alternating electromagnetic field
One or more electrical coils are carefully located on the outside of a valve body. An alternating current passing through the coil(s) results in an alternating electromagnetic field being transmitted into the valve body and valve internals. The electromagnetic field varies in intensity and polarity in the valve. As the position of a valve internal part is changed, the electromagnetic field throughout the valve body and its internals is altered. A passive receiver coil carefully located on the outside of the valve body detects the intensity of the electromagnetic field at that location as an induced electrical voltage in the coil. With the change in position of the valve internal part, there is a corresponding change in the induced voltage as a result of the alteration in the alternating electromagnetic field at that location. Changes in the voltage provide an indication of the position and motion of valve internals.
Eissenberg, David M. (Oak Ridge, TN); Haynes, Howard D. (Knoxville, TN); Casada, Donald A. (Knoxville, TN)
Generating highly uniform electromagnetic field characteristics
An apparatus and method for generating homogenous electromagnetic fields within a volume. The homogeneity provided may be for magnetic and/or electric fields, and for field magnitude, radial gradient, or higher order radial derivative. The invention comprises conductive pathways oriented about a desired region of homogeneity. A corresponding apparatus and method is provided for substantially canceling the electromagnetic field outside of the apparatus, comprising a second set of conductive pathways placed outside the first set.
Crow, James T. (Albuquerque, NM)
An apparatus and method for generating homogenous electromagnetic fields within a volume. The homogeneity provided may be for magnetic and/or electric fields, and for field magnitude, radial gradient, or higher order radial derivative. The invention comprises conductive pathways oriented mirror symmetrically about a desired region of homogeneity. A corresponding apparatus and method is provided for substantially canceling the electromagnetic field outside of the apparatus, comprising a second set of conductive pathways placed outside the first set.
Crow, James Terry (Albuquerque, NM)
An apparatus and method for generating homogenous electromagnetic fields within a volume. The homogeneity provided may be for magnetic and/or electric fields, and for field magnitude, radial gradient, or higher order radial derivative. The invention comprises conductive pathways oriented mirror symmetrically about a desired region of homogeneity. A corresponding apparatus and method is provided for substantially cancelling the electromagnetic field outside of the apparatus, comprising a second set of conductive pathways placed outside the first set.
An apparatus and method are disclosed for generating homogeneous electromagnetic fields within a volume. The homogeneity provided may be for magnetic and/or electric fields, and for field magnitude, radial gradient, or higher order radial derivative. The invention comprises conductive pathways oriented mirror symmetrically about a desired region of homogeneity. A corresponding apparatus and method is provided for substantially canceling the electromagnetic field outside of the apparatus, comprising a second set of conductive pathways placed outside the first set. 26 figs.
Crow, J.T.
An apparatus and method for generating homogeneous electromagnetic fields within a volume is disclosed. The homogeneity provided may be for magnetic and/or electric fields, and for field magnitude, radial gradient, or higher order radial derivative. The invention comprises conductive pathways oriented mirror symmetrically about a desired region of homogeneity. A corresponding apparatus and method is provided for substantially canceling the electromagnetic field outside of the apparatus, comprising a second set of conductive pathways placed outside the first set. 39 figs.
An apparatus and method are disclosed for generating homogeneous electromagnetic fields within a volume. The homogeneity provided may be for magnetic and/or electric fields, and for field magnitude, radial gradient, or higher order radial derivative. The invention comprises conductive pathways oriented about a desired region of homogeneity. A corresponding apparatus and method is provided for substantially canceling the electromagnetic field outside of the apparatus, comprising a second set of conductive pathways placed outside the first set. 55 figs.
Frequency-Domain Electromagnetic Survey | Open Energy Information
Frequency-Domain Electromagnetic Survey Frequency-Domain Electromagnetic Survey Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Technique: Frequency-Domain Electromagnetic Survey Details Activities (0) Areas (0) Regions (0) NEPA(0) Exploration Technique Information Exploration Group: Geophysical Techniques Exploration Sub Group: Electrical Techniques Parent Exploration Technique: Electromagnetic Profiling Techniques Information Provided by Technique Lithology: Detection of high-conductivity bodies in the subsurface. Stratigraphic/Structural: Hydrological: Thermal: Detection of the presence of a thermal anomaly through its resistivity signature. Cost Information Low-End Estimate (USD): 2,928.38292,838 centUSD 2.928 kUSD 0.00293 MUSD 2.92838e-6 TUSD / mile Median Estimate (USD): 4,505.20450,520 centUSD
Low-Frequency Electromagnetic Backscatter from Buried Tunnels
This progress report is submitted under a contract between the Special Project Office of DARPA and Lawrence Livermore National Laboratory. The Project Manager at DARPA is Dr. Michael Zatman. Our purpose under this contract is to investigate interactions between electromagnetic waves and a class of buried targets located in multilayered media with rough interfaces. In this report, we investigate three preliminary problems. In each case our specific goal is to understand various aspects of the electromagnetic wave interaction mechanisms with targets in layered media. The first problem, discussed in Section 2, is that of low-frequency electromagnetic backscattering from a tunnel that is cut into a lossy dielectric half-space. In this problem, the interface between the upper (free space) region and the lower (ground) region is smooth. The tunnel is assumed to be a cylindrical free-space region of infinite extent in its axial direction and with a diameter that is small in comparison to the free-space wavelength. Because its diameter is small, the tunnel can be modeled as a buried ''wire'' described by an equivalent impedance per unit length. In Section 3 we extend the analysis to include a statistically rough interface between the air and ground regions. The interface is modeled as a random-phase screen. Such a screen reduces the coherent power in a plane wave that is transmitted through it, scattering some of the total power into an incoherent field. Our analysis of this second problem quantifies the reduction in the coherent power backscattered from the buried tunnel that is caused by the roughness of the air-ground interface. The problem of low-frequency electromagnetic backscattering from two buried tunnels, parallel to each other but at different locations in the ground, is considered in Section 4. In this analysis, we wish to determine the conditions under which the presence of more than one tunnel can be detected via backscattering. Section 5 concludes the report with a summary of the investigations discussed herein and recommendations for future work on problems of this class.
Casey, K; Pao, H
Electromagnetic field radiation model for lightning strokes to tall structures
This paper describes observation and analysis of electromagnetic field radiation from lightning strokes to tall structures. Electromagnetic field waveforms and current waveforms of lightning strokes to the CN Tower have been simultaneously measured since 1991. A new calculation model of electromagnetic field radiation is proposed. The proposed model consists of the lightning current propagation and distribution model and the electromagnetic field radiation model. Electromagnetic fields calculated by the proposed model, based on the observed lightning current at the CN Tower, agree well with the observed fields at 2km north of the tower.
Motoyama, H. [CRIEPI, Tokyo (Japan); Janischewskyj, W.; Hussein, A.M. [Univ. of Toronto, Ontario (Canada); Chisholm, W.A. [Ontario Hydro Technologies, Toronto, Ontario (Canada); Chang, J.S. [McMaster Univ., Hamilton, Ontario (Canada); Rusan, R.
Self-focusing of intense high frequency electromagnetic waves in a collisional magnetoactive plasma
The self-focusing of an intense electromagnetic beam in a collisional magnetoactive plasma has been investigated by the perturbation method. Considering the relativistic and ponderomotive nonlinearities and the first three terms of perturbation expansion for the electron density and velocity, the nonlinear wave equation is obtained. This wave equation is solved by applying the source dependent expansion method and the evolution of electromagnetic beam spot-size is discussed. It is shown that the laser spot-size decreases with increasing the collision frequency and external magnetic field strength.
Niknam, A. R.; Hashemzadeh, M. [Laser and Plasma Research Institute, Shahid Beheshti University, G.C., Evin, Tehran (Iran, Islamic Republic of); Aliakbari, A.; Majedi, S. [Physics Department, Faculty of Science, Tafresh University, Tafresh (Iran, Islamic Republic of); Haji Mirzaei, F. [Physics Department, Islamic Azad University, Arak Branch, Arak (Iran, Islamic Republic of)
Electromagnetic fields: Biological and clinical aspects
Our entire biosphere is immersed in a sea of man-made electromagnetic fields (EMF). Occupational and public health data suggest that these fields may be a health hazard, possibly involving cancer and fetal loss. This paper reviews the history and pertinent physics of electromagnetic fields and presents evidence from the authors' work, and that of others, of biological interaction with living systems. Epidemiological data suggesting EMF hazards are reviewed including a discussion of possible risks associated with Hawaii's Lualualei transmitter site, TV and FM antennas in high-density population areas, fields surrounding electric power transmission and computer terminals, and the plan to route a major highway through the near-field of an operating Omega signal-source. In the face of current public fear and controversial research reports about long-term EMF exposure, suggestions are presented for public policy about these local sources of concern, as well as for the EMF risks common to any similarly developed areas. 30 refs.
Tabrah, F.L.; Batkin, S. (Department of Physiology, University of Hawaii School of Medicine, Honolulu (USA))
Resonant circuit which provides dual frequency excitation for rapid cycling of an electromagnet
Disclosed is a ring magnet control circuit that permits synchrotron repetition rates much higher than the frequency of the cosinusoidal guide field of the ring magnet during particle acceleration. the control circuit generates cosinusoidal excitation currents of different frequencies in the half waves. During radio frequency acceleration of the particles in the synchrotron, the control circuit operates with a lower frequency cosine wave and thereafter the electromagnets are reset with a higher frequency half cosine wave. Flat-bottom and flat-top wave shaping circuits maintain the magnetic guide field in a relatively time-invariant mode during times when the particles are being injected into the ring magnets and when the particles are being ejected from the ring magnets.
Praeg, Walter F. (Palos Park, IL)
Electromagnetic Compatibility from a Time-Frequency Perspective
Abstract � In wireless communication, interference between two radio systems may occur when they operate at close frequency bands, sharing the same environment at the same time. Such systems coexist if both of them perform correctly in the presence of the other. To ensure their coexistence, Electromagnetic Compatibility (EMC) is used to specify rules within standardization bodies. According to current EMC standards, the radio spectrum has been divided into non-overlapping bands often with exclusive access. However, nowadays there is a proliferation of new digital systems sharing common frequency bands because the spectrum is a limited resource. Many of them are operating in unlicensed bands regulated by The International Telecommunications Union (ITU), for example the 2.45 GHz Industrial, Scientific and Medical (ISM) band. The frequency allocation is also changing with the emergence of digital systems and this is the case for white spaces in the broadcast television (TV) spectrum. To avoid high interference levels, it is necessary to consider some parameters related to signal variations, representing more accurately the environment. Some techniques have been proposed in the literature to reduce interference levels but they are applied to specific sharing studies. Hence, we evaluate in this paper the impact of time-frequency considerations for radio coexistence. We show that EMC studies are more precise and more representative of the reality when additional parameters relevant to the time domain are taken into account in the analysis framework. We illustrate these concepts through a specific study case. We evaluate the results for different system parameters, first considering that both of them occupy the same band and then assuming that they use overlapping but non-equal frequency bands. Index Terms � Radio coexistence, electromagnetic compatibility, frequency-domain analysis, time-domain analysis.
Najett Neji; Raul De Lacerda; Alain Azoulay; Thierry Letertre
Molecular based magnets comprising vanadium tetracyanoethylene complexes for shielding electromagnetic fields
The invention presents a vanadium tetracyanoethylene solvent complex for electromagnetic field shielding, and a method for blocking low frequency and magnetic fields using these vanadium tetracyanoethylene compositions. The compositions of the invention can be produced at ambient temperature and are light weight, low density and flexible. The materials of the present invention are useful as magnetic shields to block low frequency fields and static fields, and for use in cores in transformers and motors. 21 figs.
Epstein, A.J.; Morin, B.G.
The invention presents a vanadium tetracyanoethylene solvent complex for electromagnetic field shielding, and a method for blocking low frequency and magnetic fields using these vanadium tetracyanoethylene compositions. The compositions of the invention can be produced at ambient temperature and are light weight, low density and flexible. The materials of the present invention are useful as magnetic shields to block low frequency fields and static fields, and for use in cores in transformers and motors.
Epstein, Arthur J. (Columbus, OH); Morin, Brian G. (Columbus, OH)
Strong-field spatial interference in a tailored electromagnetic bath
Light scattered by a regular structure of atoms can exhibit interference signatures, similar to the classical double-slit. These first-order interferences, however, vanish for strong light intensities, restricting potential applications. Here, we show how to overcome these limitations to quantum interference in strong fields. First, we recover the first-order interference in strong fields via a tailored electromagnetic bath with a suitable frequency dependence. At strong driving, the optical properties for different spectral bands are distinct, thus extending the set of observables. We further show that for a two-photon detector as, e.g., in lithography, increasing the field intensity leads to twice the spatial resolution of the second-order interference pattern compared to the weak-field case.
M. Macovei; J. Evers; G. -x. Li; C. H. Keitel
Electromagnetic polarizabilities: Lattice QCD in background fields
Chiral perturbation theory makes definitive predictions for the extrinsic behavior of hadrons in external electric and magnetic fields. Near the chiral limit, the electric and magnetic polarizabilities of pions, kaons, and nucleons are determined in terms of a few well-known parameters. In this limit, hadrons become quantum mechanically diffuse as polarizabilities scale with the inverse square-root of the quark mass. In some cases, however, such predictions from chiral perturbation theory have not compared well with experimental data. Ultimately we must turn to first principles numerical simulations of QCD to determine properties of hadrons, and confront the predictions of chiral perturbation theory. To address the electromagnetic polarizabilities, we utilize the background field technique. Restricting our attention to calculations in background electric fields, we demonstrate new techniques to determine electric polarizabilities and baryon magnetic moments for both charged and neutral states. As we can study the quark mass dependence of observables with lattice QCD, the lattice will provide a crucial test of our understanding of low-energy QCD, which will be timely in light of ongoing experiments, such as at COMPASS and HI gamma S.
W. Detmold, B.C. Tiburzi, A. Walker-Loud
Plenary lecture I: electromagnetic low frequency radiation from natural phenomena - data analysis and modelling
Can severe weather conditions, volcanic eruptions or even earthquakes be predicted from monitoring and analyzing electromagnetic radiation especially in very and ultra low frequency ranges? What signatures in this frequency range leave solar wind, solar ...
Ernst D. Schmitter
Waveform Distortion on a 7-Channel Heart Monitor Produced by a Worn Cable Connector & 60-Hertz Electromagnetic Fields
This case study describes an equipment-to-electromagnetic environment incompatibility that occurred in a training laboratory that is part of a large teaching hospital. Specifically, it discusses the causes of low-frequency electromagnetic fields that led to the malfunction of a 7-channel heart monitor used in cardiovascular surgical training to monitor, record, and display small electrical impulses associated with the heart.
Effects of Electromagnetic Fields on Fish and Invertebrates
In this progress report, we describe the preliminary experiments conducted with three fish and one invertebrate species to determine the effects of exposure to electromagnetic fields. During fiscal year 2010, experiments were conducted with coho salmon (Onchrohychus kisutch), California halibut (Paralicthys californicus), Atlantic halibut (Hippoglossus hippoglossus), and Dungeness crab (Cancer magister). The work described supports Task 2.1.3: Effects on Aquatic Organisms, Subtask 126.96.36.199: Electromagnetic Fields.
Schultz, Irvin R.; Woodruff, Dana L.; Marshall, Kathryn E.; Pratt, William J.; Roesijadi, Guritno
Magnetic field effect on stimulated Raman scattering of electromagnetic waves from nanoparticle lattice
The influence of a static magnetic field on the Raman scattering of a millimeter pump wave propagating through periodic nanoparticles is studied. Formulas for the growth rate of the scattered electromagnetic wave and the electrostatic wave are derived and analyzed. It is found that the growth rate for the backscattering case is larger than that of forward scattering and the growth rate is increased by the static magnetic field. A resonance in the dispersion relation of the electromagnetic wave is found as a combination of the cyclotron and plasma frequency. However, no instability was found for this lower branch of the dispersion curve.
Chakhmachi, A. [Plasma Physics and Nuclear Fusion Research School, Nuclear Science and Technology Research Institute, P.O. Box 14155-1339, Tehran (Iran, Islamic Republic of); Maraghechi, B. [Department of Physics, Amirkabir University of Technology, P.O. Box 15875-4413, Tehran (Iran, Islamic Republic of)
Electromagnetic field of a charge intersecting a cold plasma boundary in a waveguide
We analyze the electromagnetic field of a charge crossing a boundary between a vacuum and cold plasma in a waveguide. We obtain exact expressions for the field components and the spectral density of the transition radiation. With the steepest descent technique, we investigate the field components. We show that the electromagnetic field has a different structure in a vacuum than in cold plasma. We also develop an algorithm for the computation of the field based on a certain transformation of the integration path. The behavior of the field depending on distance and time and the spectral density depending on frequency are explored for different charge velocities. Some important physical effects are noted. A considerable increase and concentration of the field near the wave front in the plasma is observed for the case of ultrarelativistic particles. In the plasma, the mode envelopes and spectral density show zero points when the charge velocity is within certain limits.
Alekhina, Tatiana Yu.; Tyukhtin, Andrey V. [Radiophysics Department of St. Petersburg University, 1 Ulyanovskaya, St. Petersburg 198504 (Russian Federation)
An investigation of the usefulness of extremely low-frequency electromagnetic measurements for treaty verification
From FY 1986 through FY 1988, we monitored extremely low-frequency (ELF) electromagnetic (EM) fields to determine whether these signals could be detected from underground nuclear explosions. Signals clearly related to underground tests were detected only when the ELF field sensors were located within 10 km of surface ground zero. Theoretical analysis, based on the results of these measurements, shows that the ELF impulse signals from underground nuclear tests are of longer duration than those from lightning sources and are, therefore, less efficient in exciting resonances in the earth-ionosphere cavity, even though the source strength for each may be the same. Thus, ELF signals from underground nuclear tests with yields of <150 kT are generally lower than the background signals caused by worldwide lightning activity. Our conclusion is that ELF monitoring probably will not be useful for detecting underground nuclear tests at distances >10 km from the tests. 16 refs., 24 figs., 3 tabs.
Sweeney, J.J.
From FY 1986 through FY 1988, we monitored extremely low-frequency (ELF) electromagnetic (EM) fields to determine whether these signals could be detected from underground nuclear explosions. Signals clearly related to underground tests were detected only when the ELF field sensors were located within 10 km of surface ground zero. Theoretical analysis, based on the results of these measurements, shows that the ELF impulse signals from underground nuclear tests are of longer duration than those from lightning sources and are, therefore, less efficient in exciting resonances in the earth-ionosphere cavity, even though the source strength for each may be the same. Thus, ELF signals from underground nuclear tests with yields of nuclear tests at distances >10 km from the tests. 16 refs., 24 figs., 3 tabs.
Electromagnetic and mechanical design of gridded radio-frequency cavity windows
Electromagnetic, thermal and structural analyses of radio-frequency (RF) cavities were performed as part of a developmental RF cavity program for muon cooling. RF cavities are necessary to provide longitudinal focusing of the muons and to compensate for their energy loss. Closing the cavity ends by electrically conducting windows reduces the power requirement and increases the on-axis electric field for a given maximum surface electric field. Many factors must be considered in the design of RF cavity windows. RF heating can cause the windows to deform in the axial direction of the cavity. The resulting thermal stresses in the window must be maintained below the yield stress of the window material. The out-of-plane deflection must be small enough so that the consequent frequency shift is tolerable. For example, for an 805 MHz cavity, the out-of-plane deflection must be kept below 25 microns to prevent the frequency of the cavity from shifting more than 10 kHz. In addition, the window design should yield smooth electric and magnetic fields, terminate field leakage beyond the window, and minimize beam scattering. In the present thesis, gridded-tube window designs were considered because of their high structural integrity. As a starting point in the analysis, a cylindrical pillbox cavity was considered as a benchmark problem. Analytical and finite element solutions were obtained for the electric and magnetic fields, power loss density, and temperature profile. Excellent agreement was obtained between the analytical and finite element results. The finite element method was then used to study a variety of gridded-tube windows. It was found that cooling of the gridded-tube windows by passing helium gas inside the tubes significantly reduces the out-of-plane deflection and the thermal stresses. Certain tube geometries and grid patterns were found to satisfy all of the design requirements.
Alsharoa, Mohammad M.; /IIT, Chicago /Fermilab
Improper Rotations'Symmetry of Electromagnetic Field and New Conserved Quantity of Complex Fields
It is established the partition of linear space $$ over the field of genuine scalars and pseudoscalars, the vectors in which are sets of contravariant and covariant electromagnetic field tensors and pseudotensors $F^{\\mu\
Yearchuck, D
Fractional Effective Action at strong electromagnetic fields
In 1936, Weisskopf showed that for vanishing electric or magnetic fields the strong-field behavior of the one loop Euler-Heisenberg effective Lagrangian of quantum electro dynamics (QED) is logarithmic. Here we generalize this result for different limits of the Lorentz invariants \\(\\vec{E}^2-\\vec{B}^2\\) and \\(\\vec{B}\\cdot\\vec{E}\\). The logarithmic dependence can be interpreted as a lowest-order manifestation of an anomalous power behavior of the effective Lagrangian of QED, with critical exponents \\(\\delta=e^2/(12\\pi)\\) for spinor QED, and \\(\\delta_S=\\delta/4\\) for scalar QED.
Hagen Kleinert; Eckhard Strobel; She-Sheng Xue
Low frequency electromagnetic oscillations in dense degenerate electron-positron pair plasma, with and without ions
Quantum plasma oscillations are studied in a strongly magnetized, ultra-dense plasma with degenerate electrons and positrons. The dispersive role of electron and positron quantum effects on low frequency (in comparison to electron cyclotron frequency) shear electromagnetic wave is investigated by employing hydrodynamic formulation. In the presence of ions, the density balance changes, and the electromagnetic wave (with frequency lower than the ion cyclotron frequency) is shown to couple with electrostatic ion mode under certain conditions. For such low frequency waves, it is also seen that the contribution of electron and positron degeneracy pressure is dominant as compared to their diffraction effects. The results are analyzed numerically for illustrative purpose pointing out their relevance to the dense laboratory (e.g., super-intense laser-dense matter interactions) and astrophysical plasmas.
Khan, S. A. [National Centre for Physics, Quaid-i-Azam University Campus, Islamabad 45320 (Pakistan); Ayub, M. K. [National Centre for Physics, Quaid-i-Azam University Campus, Islamabad 45320 (Pakistan); Theoretical Plasma Physics Division, PINSTECH, P. O. Nilore, Islamabad (Pakistan); Pohang University of Science and Technology (POSTECH), Pohang, Gyunbuk 790-784 (Korea, Republic of); Ahmad, Ali [National Centre for Physics, Quaid-i-Azam University Campus, Islamabad 45320 (Pakistan); Theoretical Plasma Physics Division, PINSTECH, P. O. Nilore, Islamabad (Pakistan); Department of Physics, COMSATS Institute of Information Technology, Islamabad 44000 (Pakistan)
Low frequency electromagnetic prospecting system. [Grass Valley, KGRA
A prototype portable electromagnetic sounding system was assembled and depth sounding survey was conducted in Grass Valley, Nevada, as a part of a program to evaluate geophysical techniques in geothermal exploration. A horizontal loop transmitter of radius 50 meters operating between .01 Hz and 100 Hz was used in conjunction with a SQUID magnetometer. A digital synchronous detector was used for on site processing of magnetometer output. This detector allowed useful data acquisition with transmitter-receiver separation of up to 2 km with power requirements of less than 72 watts. Conductive sediments (1 to 10 ohm-m) of thicknesses of up to 1.5 km were well resolved with this system, and the interpreted sections compared very well with dc resistivity measurements made with much heavier equipment and larger arrays in the same area.
Jain, B.K.
Low frequency electrostatic and electromagnetic modes in nonuniform cold quantum plasmas
The low frequency electrostatic and electromagnetic linear modes in a nonuniform cold quantum electron-ion plasma are studied. The effect of stationary dust on an electrostatic mode is also investigated. The quantum corrections in the linear dispersion relations of a cold dense plasma are presented with possible applications.
Saleem, H.; Ahmad, Ali [Theoretical Plasma Physics Division, Pakistan Institute of Nuclear Science and Technology (PINSTECH), Islamabad (Pakistan); Department of Physics, COMSATS Institute of Information Technology (CIIT), Islamabad (Pakistan); Khan, S. A. [Department of Physics, COMSATS Institute of Information Technology (CIIT), Islamabad (Pakistan); Department of Physics, Government College Bagh AJK (Pakistan)
Unusual formations of the free electromagnetic field in vacuum
It is shown that there are exact solutions of the free Maxwell equations (FME) in vacuum allowing an existence of stable spherical formations of the free magnetic field and ring-like formations of the free electric field. It is detected that a form of these spheres and rings does not change with time in vacuum. It is shown that these convergent solutions are the result of an interference of some divergent solutions of FME. One can surmise that these electromagnetic formations correspond to Kapitsa's hypothesis about interference origin and a structure of fireball.
Andrew E. Chubykalo; Augusto Espinoza
Method and split cavity oscillator/modulator to generate pulsed particle beams and electromagnetic fields
A compact device called the split cavity modulator whose self-generated oscillating electromagnetic field converts a steady particle beam into a modulated particle beam. The particle beam experiences both signs of the oscillating electric field during the transit through the split cavity modulator. The modulated particle beam can then be used to generate microwaves at that frequency and through the use of extractors, high efficiency extraction of microwave power is enabled. The modulated beam and the microwave frequency can be varied by the placement of resistive wires at nodes of oscillation within the cavity. The short beam travel length through the cavity permit higher currents because both space charge and pinching limitations are reduced. The need for an applied magnetic field to control the beam has been eliminated.
Clark, M.C.; Coleman, P.D.; Marder, B.M.
Clark, M. Collins (Albuquerque, NM); Coleman, P. Dale (Albuquerque, NM); Marder, Barry M. (Albuquerque, NM)
Rayleigh-Taylor-Induced electromagnetic fields in laser-produced plasmas
Spontaneous electromagnetic fields can be important to the dynamic evolution of a plasma by directing heat flow as well as providing additional pressures on the conducting fluids through the Lorentz force. Electromagnetic ...
Manuel, Mario John-Errol
Generation and Manipulation of Multi-Color Stationary Light Field Using Electromagnetically Induced Transperancy
Dynamic control of a weak quantum probe light pulse for the generation and quantum manipulations of a stationary multi-color (MC-) light field in a resonant coherent atomic medium using electromagnetically induced transparency is proposed. The manipulations have been analyzed based on the analytical solution of the adiabatic limit in the evolution of MC-light fields resulting from interaction of the slow probe light with the new fields generated in the nondegenerate multi-wave mixing scheme. We have found a critical stopping condition for the MC-light fields where the group velocity of light should reduce down to zero. Semiclassical dynamics and behavior of specific quantum correlations of the MC-light fields have been studied in detail for particular initial quantum states of the probe pulse. The stationary MC-field dynamics are treated in terms of dark MC-polariton states constructed for the studied multi-wave mixing processes. We have found the conditions for optimal manipulation of the MC-light while preserving the delicate quantum correlations of the initial probe light pulse. The quantum manipulations leading to the frequency and direction switching of the initial probe light pulse as well as to the quantum swapping of probe light into the new multi-frequency light fields have been proposed. The possibilities of the interaction time lengthening and enhancement of the electric field amplitudes of the stationary MC-light are also discussed for enhancement of the interactions with weak quantum fields in the spatially limited media.
S. A. Moiseev; B. S. Ham
Electromagnetic Forces and Fields in a Rotating Reference Frame
Maxwell�s equations and the equations governing charged particle dynamics are presented for a rotating coordinate system with the global time coordinate of an observer on the rotational axis. Special care is taken in defining the relevant entities in these equations. Ambiguities in the definitions of the electromagnetic fields are pointed out, and in fact are shown to be essential in such a system of coordinates. The Lorentz force is found to have an extra term in this frame, which has its origins in relativistic mass. A related term in the energy equation, which allows inertia to be gained even during strict corotation, suggests ways existing pulsar magnetosphere models may be modified to match observed �braking indices � more closely. Subject headings: magnetic fields � relativity � pulsars: general � 3 �
Paul N. Arendt
On inverse scattering at high energies for the multidimensional Newton equation in electromagnetic field
We consider the multidimensional (nonrelativistic) Newton equation in a static electromagnetic field $$\\ddot x = F(x,\\dot x), F(x,\\dot x)=-\
Alexandre Jollivet
Correspondence between Electro-Magnetic Field and other Dark Energies in Non-linear Electrodynamics
In this work, we have considered the flat FRW model of the universe filled with electro-magnetic field. First, the Maxwell's electro-magnetic field in linear form has been discussed and after that the modified Lagrangian in non-linear form for accelerated universe has been considered. The corresponding energy density and pressure for non-linear electro-magnetic field have been calculated. We have found the condition such that the electro-magnetic field generates dark energy. The correspondence between the electro-magnetic field and the other dark energy candidates namely tachyonic field, DBI-essence, Chaplygin gas, hessence dark energy, k-essenece and dilaton dark energy have been investigated. We have also reconstructed the potential functions and the scalar fields in this scenario.
Maity, Sayani; Debnath, Ujjal
Sayani Maity; Shuvendu Chakraborty; Ujjal Debnath
Effect of electron density profile on power absorption of high frequency electromagnetic waves in plasma
Considering different typical electron density profiles, a multi slab approximation model is built up to study the power absorption of broadband (0.75-30 GHz) electromagnetic waves in a partially ionized nonuniform magnetized plasma layer. Based on the model, the power absorption spectra for six cases are numerically calculated and analyzed. It is shown that the absorption strongly depends on the electron density fluctuant profile, the background electron number density, and the collision frequency. A potential optimum profile is also analyzed and studied with some particular parameters.
Xi Yanbin; Liu Yue [MOE Key Laboratory of Materials Modification by Laser, Electron, and Ion Beams, School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China)
Frequency Selective Surfaces as Near Infrared Electro-Magnetic Filters for Thermophotovoltaic Spectral Control
Frequency selective surfaces (FSS) effectively filter electromagnetic radiation in the microwave band (1mm to 100mm). Interest exists in extending this technology to the near infrared (1 {micro}m to 10 {micro}m) for use as a filter of thermal radiation in thermophotovoltaic (TPV) direct energy conversion. This paper assesses the ability of FSS to meet the strict spectral performance requirements of a TPV system. Inherent parasitic absorption, which is the result of the induced currents in the FSS metallization, is identified as a significant obstacle to achieving high spectral performance.
Ryan T. Kristensen; John F. Beausang; David M. DePoy
Frequency selective surfaces (FSS) effectively filter electromagnetic radiation in the microwave band (1 mm to 100 mm). Interest exists in extending this technology to the near infrared (1 {micro}m to 10 {micro}m) for use as a filter of thermal radiation in thermophotovoltaic (TPV) direct energy conversion. This paper assesses the ability of FSS to meet the strict spectral performance requirements of a TPV system. Inherent parasitic absorption, which is the result of the induced currents in the FSS metallization, is identified as a significant obstacle to achieving high spectral performance.
RF Kristensen; JF Beausang; DM DePoy
Effect of Electromagnetic Fields on the Filtration of Aluminium ...
Numerical Modeling of Centrifugally Cast HSS Rolls � Numerical Simulation of Electro-magnetic Turbulent Inhibitor Technology in a Tundish � Optimizing the�...
Visualizing electromagnetic field and particle simulations in accelerators with ParaView
SLAC performs large-scale simulations of Electromagnetic fields and particles for accelerator applications. These simulations run on intricate high order finite element meshes and produce field strengths spanning tens of orders of magnitudes. Such simulations ...
Greg L. Schussman
The booster synchrotron for NSLS-II will include a 7-cell PETRA cavity, which was manufactured for the PETRA-II project at DESY. The cavity fundamental frequency operates at 500 MHz. In order to verify the impedances of the fundamental and higher-order modes (HOM), which were calculated by computer code, we measured the magnitude of the electromagnetic field of the fundamental acceleration mode and HOM using the bead-pull method. To keep the cavity body temperature constant, we used a chiller system to supply cooling water at 20 degrees C. The bead-pull measurement was automated with a computer. We encountered some issues during the measurement process due to the difficulty in measuring the electromagnetic field magnitude in a multi-cell cavity. We describe the method and apparatus for the field measurement, and the obtained results.
Kawashima, Y.; Blednykh, A.; Cupolo, J.; Davidsaver, M.; Holub, B.; Ma, H.; Oliva, J.; Rose, J.; Sikora, R.; Yeddulla, M.
Brief paper: Controlling the motion of charged particles in a vacuum electromagnetic field from the boundary
We consider the problem of driving two non-relativistic charged particles in a bounded vacuum electromagnetic field to the same location by applying electromagnetic forces through the boundary of the domain. The dynamics of the particles is modeled by ... Keywords: Boundary feedback, Charged particle, Maxwell-Lorentz system, Nuclear fusion, Perturbed energy
Luis R. Suazo; Weijiu Liu
Evidences of regulatory and signalling role of electromagnetic fields in biological objects: review of literature and own studies
There are growing evidence supporting the role of electromagnetic fields and interactions in biological processes. In this paper we're trying to theoretically substantiate the feasibility and necessity of the "Theory of Electromagnetic Biological Regulation ... Keywords: antibodies, biological regulation, cell, electromagnetic field, signalling, viruses
Valeriy Zaporozhan; Andriy Ponomarenko
Electromagnetically induced vorticity control in a quantum fluid velocity field
A new method is reported by which it is possible to induce certain flux configurations of desired characteristics via electromagnetic means into the overall quantum probability current of a many-body system in the Madelung hydrodynamic picture. Some indicative applications are also considered with emphasis in HTC and gravitational wave research.
T. E. Raptis
Electromagnetic fields and transport coefficients in a hot pion gas
We present recent results on finite temperature electromagnetic form factors and the electrical conductivity in a pion gas. The standard Chiral Perturbation Theory power counting needs to be modified for transport coefficients. We pay special attention to unitarity and to possible applications for dilepton and photon production.
A. Gomez Nicola; D. Fernandez-Fraile
Utilization of electromagnetic detector for selection and detection of high-frequency relic gravitational waves
It is shown that coupling system between fractal membranes and a Gaussian beam passing through a static magnetic field has strong selection capability for the stochastic relic gravitational wave background. The relic GW components propagating along the positive direction of the symmetrical axis of the Gaussian beam might generate an optimal electromagnetic perturbation while the perturbation produced by the relic GW components propagating along the negative and perpendicular directions to the symmetrical axis will be much less than the former.The influence of the random fluctuation of the relic GWs to such effect can be neglected and the influence of the random fluctuation of the relic GWs to such effect can be neglected.
Fangyu Li; Zhenya Chen; Ying Yi
The influence of an electromagnetic field on the wave-current interaction
We study the propagation of surface waves on a current in the presence of an electromagnetic field. A horizontal (vertical) field strengthens (weakens) the counter-current which blocks the waves. We compute the phase space diagrams (blocking velocities versus period of the waves) with and without surface tension. Three new dimensionless numbers are introduced to compare the relative strengths of gravity, surface tension and field effects. This work shows the importance of an electromagnetic field in order to design wave-breakers or in microfluidics applications.
Germain Rousseaux; Philippe Ma�ssa
Electron interference in mesoscopic devices in the presence of nonclassical electromagnetic fields
The interaction of mesoscopic interference devices with nonclassical electromagnetic fields is studied. The external quantum fields induce a phase factor on the electric charges. This phase factor, which is a generalization of the standard Aharonov-Bohm phase factor, is in the case of nonclassical electromagnetic fields a quantum mechanical operator. Its expectation value depends on the density matrix describing the nonclassical photons and determines the interference. Several examples are discussed, which show that the quantum noise of the nonclassical photons destroys slightly the electron interference fringes. An interesting application arises in the context of distant electron interference devices, irradiated with entangled photons. In this case the interfering electrons in the two devices become entangled. The same ideas are applied in the context of SQUID rings irradiated with nonclassical electromagnetic fields. It is shown that the statistics of the Cooper pairs tunneling through the Josephson junction depend on the statistics of the photons.
D. I. Tsomokos; C. C. Chong; A. Vourdas
of electric and magnetic fields emitted from Australian trams, trains and hybrid cars were investigated cars are now electrically operated, therefore emitting less CO2 and less pollution into the environmentMEASUREMENT AND ANALYSIS OF ELECTROMAGNETIC FIELDS FROM TRAMS, TRAINS AND HYBRID CARS Malka N
Halgamuge, Malka N.
Electromagnetic field of the large power cables and impact on the human health
In this work we survey our research on domain decomposition and related algorithms for large power electric cables and the impact on the human health. The equations that describe the behaviour of the fields in electromagnetic devices are coupled because ... Keywords: bioheat equation, coupled fields, electrical cables, finite element method
Daniela C�rstea
Electromagnetic field of the large power cables and interaction with the human body
Free Form of the Foldy-Wouthuysen Transformation in External Electromagnetic Fields
We derive the exact Foldy-Wouthuysen transformation for Dirac fermions in a time independent external electromagnetic field in the basis of the Ritus eigenfunctions, namely the eigenfunctions of the operator $(\\gamma \\cdot \\Pi)^2$, with $\\Pi^\\mu = p^\\mu - e A^\\mu$. In this basis, the transformation acquires a free form involving the dynamical quantum numbers induced by the field.
Gabriela Murguia; Alfredo Raya
High-frequency electric field measurement using a toroidal antenna
A simple and compact method and apparatus for detecting high frequency electric fields, particularly in the frequency range of 1 MHz to 100 MHz, uses a compact toroidal antenna. For typical geophysical applications the sensor will be used to detect electric fields for a wide range of spectrum starting from about 1 MHz, in particular in the frequency range between 1 to 100 MHz, to detect small objects in the upper few meters of the ground. Time-varying magnetic fields associated with time-varying electric fields induce an emf (voltage) in a toroidal coil. The electric field at the center of (and perpendicular to the plane of) the toroid is shown to be linearly related to this induced voltage. By measuring the voltage across a toroidal coil one can easily and accurately determine the electric field.
Lee, Ki Ha (Lafayette, CA)
Particle production in strong electromagnetic fields in relativistic heavy-ion collisions
I review the origin and properties of electromagnetic fields produced in heavy ion collisions. The field strength immediately after a collision is proportional to the collision energy and reaches eB\\sim(m_\\pi)^2 at RHIC and eB\\sim10 (m_\\pi)^2 at LHC. I demonstrate by explicit analytical calculation that after dropping by about one-two orders of magnitude during the first fm/c of plasma expansion, it freezes out and lasts for as long as quark-gluon plasma exists as a consequence of finite electrical conductivity of the plasma. Magnetic field breaks spherical symmetry in the direction perpendicular to the reaction plane and therefore all kinetic coefficients are anisotropic. I examine viscosity of QGP and show that magnetic field induces azimuthal anisotropy on plasma flow even in spherically symmetric geometry. Very strong electromagnetic field has an important impact on particle production. I discuss the problem of energy loss and polarization of fast fermions due to synchrotron radiation, consider photon decay induced by magnetic field, elucidate J/Psi dissociation via Lorentz ionization mechanism and examine electromagnetic radiation by plasma. I conclude that all processes in QGP are affected by strong electromagnetic field and call for experimental investigation.
Kirill Tuchin
Efficient Inversion of Multi-frequency and Multi-source Electromagnetic Data: Final report
BES grant DE-FG02-06ER15819 supported efforts at Oregon State University (OSU) to develop improved inversion methods for 3D subsurface electromagnetic (EM) imaging. Three interrelated activities have been supported by this grant, and its predecessor (DE-FG02-06ER15818): (1) collaboration with a former student of the PI, Dr. Weerachai Siripunvaraporn (now Professor at Mahidol University in Bangkok, Thailand) on developing and refining inversion methods for 3D Magnetotelluric (MT) data . (2) Development at Oregon State University of a new modular system of computer codes for EM inversion, and initial testing and application of this inversion on several large field data sets. (3) Research on more efficient approaches to multi-transmitter EM inverse problems, to optimize use of expensive data sensitivity calculations needed for gradient based inversion schemes. The last of these activities was the main motivation for this research project, but the first two activities were important enabling steps that produced useful products and results in their own right, including freely avaialable software for 3D inversion of EM geophysical data.
Gary D. Egbert
Stable pseudoanalytical computation of electromagnetic fields from arbitrarily-oriented dipoles in cylindrically stratified media
Computation of electromagnetic fields due to point sources (Hertzian dipoles) in cylindrically stratified media is a classical problem for which analytical expressions of the associated Green's function (tensor) have been long known. However, under finite-precision arithmetic, direct numerical computations based on the application of such analytical (canonical) expressions invariably lead to underflow and overflow problems related to the behavior of the eigenfunctions (cylindrical Bessel and Hankel functions) for extreme arguments and/or high-order, as well as convergence problems related to the numerical integration over the spectral wavenumber and to the truncation of the infinite series over the azimuth mode number. These problems are exacerbated when a disparate range of values is to be assumed for the layers' thicknesses and material parameters (resistivities, permittivities, and permeabilities), the transverse and longitudinal distances between source and observation points, as well as the source frequency. To overcome these challenges in a systematic fashion, we introduce here different sets of range-conditioned, modified cylindrical functions (in lieu of standard cylindrical eigenfunctions), each associated with nonoverlapped subdomains of (numerical) evaluation to allow for stable computations under any range of physical parameters. In addition, adaptively-chosen integration contours are employed in the complex spectral wavenumber plane to ensure convergent numerical integration in all cases. We illustrate the application of the algorithm to problems of geophysical interest.
H. Moon; F. L. Teixeira; B. Donderici
Dual Symmetric Solution of Maxwell Equations and Correct Quantization of Electromagnetic Field
It has been found, that free electromagnetic (EM) field in restricted volume (typical experimental case) consists of two independent and equally possible components with different parity under spatial inversion transformations. Either of the two components indicated represents the system of also two independent and equally possible fields, which are even and uneven under time reversal transformations. The rules for local quantization of EM-field in Minkowski space are obtained.
A. Dovlatova; D. Yearchuck; Y. Yerchak; A. Alexandrov
An experimental foundation for electromagnetic shower formation in the geomagnetic field
At very high energies the Earth magnetic field, although in many other connections conside red rather weak, acts as a strong field on photons and leptons. This paper discusses the i ntimate connection between this effect and the corresponding `strong field effects' observ ed at accessible accelerator energies in aligned single crystals. As such, these effects c onstitute an experimental verification of the theoretical basis used for simulations of th e development of electromagnetic showers in magnetic fields, in particular the geomagnetic field. A short discussion of more general aspects of the shower development in the fields present at different distance scales is included.
U. I. Uggerh�j
Review of High Frequency Conducted Susceptibility Limits for Electromagnetic Compatibility Testing
To continue meeting safety and reliability requirements while controlling costs, operators of nuclear power plants must be able to replace and upgrade equipment in a cost-effective manner. One issue that has been problematic for new plant equipment and especially for digital instrumentation and control (I&C) systems in recent years is electromagnetic compatibility (EMC). The EMC issue usually involves testing to show that critical equipment will not be adversely affected by electromagnetic interference (...
Quantum interference of electromagnetic fields from remote quantum memories
We observe quantum, Hong-Ou-Mandel, interference of fields produced by two remote atomic memories. High-visibility interference is obtained by utilizing the finite atomic memory time in four-photon delayed coincidence measurements. Interference of fields from remote atomic memories is a crucial element in protocols for scalable generation of multi-node remote qubit entanglement.
T. Chaneliere; D. N. Matsukevich; S. D. Jenkins; S. -Y. Lan; R. Zhao; T. A. B. Kennedy; A. Kuzmich
Interpreting marine controlled source electromagnetic field behaviour with streamlines
Streamlines represent particle motion within a vector field as a single line structure and have been used in many areas of geophysics. We extend the concept of streamlines to interactive three dimensional representations of the coupled vector fields ... Keywords: CSEM, Hydrocarbon Exploration, Interactive, MCSEM, Streamlines
A. M. Pethick, B. D. Harris
Generation of electromagnetic radiation based on nanotubes under a constant electric field and an electromagnetic wave field
The possible generation of radiation in the millimeter range based on nanotubes by an alternating (rapidly oscillating) electric field under a constant (or nonstationary) electric field is studied. Radiation enhancement is based on a periodic dependence of the current in nanotubes in such electric fields. The results of a mathematical simulation are presented.
Sadykov, N. R., E-mail: firstname.lastname@example.com; Scorkin, N. A. [South Ural State University (Russian Federation)
Design of near-field optical probes with optimal field enhancement by finite difference time domain electromagnetic simulation
March 2002 We report the three-dimensional electromagnetic simulation of gold nanoparticles FDTD simulations of gold particles illuminated by near infrared radiation are performed. Field regime was not possible until more recently. In 1984, Pohl et al. were able to image a test sample at 25
Xie, Xiaoliang Sunney
Would be the photon a composed particle? quantization of field fluxes in electromagnetic radiation
[En] Here it is made a comparative analysis between the classical and the quantum expressions for the energy of electromagnetic radiation (ER). The comparison points to the possibility of the quantization of the magnetic and the electric field fluxes in the ER.
Celso de Araujo Duarte
Effect of Electromagnetic Fields on the Filtration of Liquid Aluminum ...
... Shahin Akbarnejad, Knut Marthinsen, Jon Arne Bakken, Ragnhild Elizabeth Aune ... aluminum alloy (A356) by the support of various magnetic field strengths (up to ... The obtained results were compared with reference gravity experiments.
Direct measurement of the quantum state of the electromagnetic field in a superconducting transmission line
We propose an experimental procedure to directly measure the state of an electromagnetic field inside a resonator, corresponding to a superconducting transmission line, coupled to a Cooper-pair box (CPB). The measurement protocol is based on the use of a dispersive interaction between the field and the CPB, and the coupling to an external classical field that is tuned to resonance with either the field or the CPB. We present a numerical simulation that demonstrates the feasibility of this protocol, which is within reach of present technology.
F. de Melo; L. Aolita; F. Toscano; L. Davidovich
Electromagnetically superconducting phase of QCD vacuum induced by strong magnetic field
In this talk we discuss our recent suggestion that the QCD vacuum in a sufficiently strong magnetic field (stronger than 10^{16} Tesla) may undergo a spontaneous transition to an electromagnetically superconducting state. The possible superconducting state is anisotropic (the vacuum exhibits superconductivity only along the axis of the uniform magnetic field) and inhomogeneous (in the transverse directions the vacuum structure shares similarity with the Abrikosov lattice of an ordinary type-II superconductor). The electromagnetic superconductivity of the QCD vacuum is suggested to occur due to emergence of specific quark-antiquark condensates which carry quantum numbers of electrically charged rho mesons. A Lorentz-covariant generalization of the London transport equations for the magnetic-field-induced superconductivity is given.
M. N. Chernodub
In this talk we discuss our recent suggestion that the QCD vacuum in a sufficiently strong magnetic field (stronger than 10{sup 16} Tesla) may undergo a spontaneous transition to an electromagnetically superconducting state. The possible superconducting state is anisotropic (the vacuum exhibits superconductivity only along the axis of the uniform magnetic field) and inhomogeneous (in the transverse directions the vacuum structure shares similarity with the Abrikosov lattice of an ordinary type-II superconductor). The electromagnetic superconductivity of the QCD vacuum is suggested to occur due to emergence of specific quark-antiquark condensates which carry quantum numbers of electrically charged rho mesons. A Lorentz-covariant generalization of the London transport equations for the magnetic-field-induced superconductivity is given.
Chernodub, M. N. [CNRS, Laboratoire de Mathematiques et Physique Theorique, Universite Francois-Rabelais Tours, Federation Denis Poisson, Parc de Grandmont, 37200 Tours (France); Department of Physics and Astronomy, University of Gent, Krijgslaan 281, S9, B-9000 Gent (Belgium)
Harmonic filters influences regarding the power quality on high frequency electrothermal installation with electromagnetic induction
This paper presents a study regarding the functioning of a melting/hardening electrothermal installation with electromagnetic induction from the point of view of generated harmonics in the power distribution. The authors made simulations in scope of ... Keywords: electrothermal installation, harmonic, passive filters, static converter
Raluca Rob; Ioan Sora; Caius Panoiu; Manuela Panoiu
Coupled Deconvolution for Frequency Extrapolation of Electromagnetic Solutions with Matrix Pencil Method
of electromagnetic solutions," 2005 IEEE AP-S International Symposium, Washington, DC, July 2005. [2] Alan V extrapolation results to achieve a lower error level. We first define two window functions in the solution in the interval (fL, fmax). Fig. 1 shows two Chebyshev windows that are constructed in this manner. Forward MPM
Gürel, Levent
Detection of electromagnetic waves using MEMS antennas
We describe the design, fabrication and characterization of simple micromechanical structures that are capable of sensing static electric time varying electromagnetic fields. Time varying electric field sensing is usually achieved using an electromagnetic antenna and a receiver. However, these antenna-based approaches do not exhibit high sensitivity over a broad frequency (or wavelength) range. An important aspect of the present work is that, in contrast to traditional antennas, the dimensions of these micromechanical oscillators can be much smaller than the wavelength of the electromagnetic wave. We characterized the fabricated micromechanical oscillators by measuring their responses to time varying electric and electromagnetic fields.
Lavrik, Nickolay V [ORNL; Tobin, [Oak Ridge National Laboratory (ORNL); Bowland, Landon T [ORNL
Enhancement of electromagnetic propagation through complex media for Radio Frequency Identification
In this thesis, I present and examine the fundamental limitations involved in Radio Frequency Identification (RFID) as well as provide a means to improve reader-tag communication in ultra high frequency RFID systems. The ...
Marti, Uttara P
Instabilities and generation of a quasistationary magnetic field by the interaction of relativistically intense electromagnetic wave with a plasma
It is shown that the interaction of the superstrong laser radiation with an isotropic plasma leads to the generation of low frequency electromagnetic (EM) waves and in particular a quasistationary magnetic field. When the relativistic circularly polarized transverse EM wave propagates along z-axis, it creates a ponderomotive force, which affects the motion of particles along the direction of its propagation. On the other hand, motion of the particles across the direction of propagation is defined by the ponderomotive potential. The dispersion relation for the transverse EM wave using a special distribution function, which has an anisotropic form, is derived. The dispersion relation is subsequently investigated for a number of special cases. In general, it is shown that the growth rate of the EM wave strongly depends upon its intensity.
Gillani, S. S. A.; Shah, H. A. [Department of Physics, Government College University, Lahore 54000 (Pakistan); Tsintsadze, N. L. [Department of Physics, Government College University, Lahore 54000 (Pakistan); Salam Chair in Physics, Government College University, Lahore 54000 (Pakistan); Institute of Physics, Tbilisi 380077 (Georgia); Razzaq, M. [Department of Physics, Government College University, Lahore 54000 (Pakistan); Salam Chair in Physics, Government College University, Lahore 54000 (Pakistan)
A Review of the European Union's Directive on Limiting Exposure of Workers to Electromagnetic Fields
The European Union�s Directive on Limiting Exposure of Workers to Electromagnetic Fields (EMF) adopts exposure limits based on guidance from the International Commission on Non-Ionizing Radiation Protection (ICNIRP). This report presents a summary of the draft Directive concerning workplace exposure limits and compliance issues. The summary explains quantitative EMF exposure limits in general and clarifies the Directive�s use of the terms exposure limit values (ELV) and action ...
Potential Effects of Electromagnetic Fields from Submerged Electrical Cables on Aquatic Life
There is considerable interest in the development of marine and hydrokinetic (MHK) energy projects in the rivers, estuaries, and coastal ocean waters of the United States. MHK technologies convert the energy of waves or the moving water in river or tidal currents into electricity, without the impacts of dams and impoundments associated with conventional hydropower or the extraction and combustion of fossil fuels. However, electromagnetic fields (EMFs) will be created by the generators, transformers, rect...
On inverse problems in electromagnetic field in classical mechanics at fixed energy
In this paper, we consider inverse scattering and inverse boundary value problems at sufficiently large and fixed energy for the multidimensional relativistic and nonrelativistic Newton equations in a static external electromagnetic field $(V,B)$, $V\\in C^2,$ $B\\in C^1$ in classical mechanics. Developing the approach going back to Gerver-Nadirashvili 1983's work on an inverse problem of mechanics, we obtain, in particular, theorems of uniqueness.
Laboratory Studies of the Short-term Responses of Freshwater Fish to Electromagnetic Fields
Hydrokinetic energy technologies are being proposed as an environmentally preferred means of generating electricity from river and tidal currents. Among the potential issues that must be investigated in order to resolve environmental concerns are the effects on aquatic organisms of electromagnetic fields created by underwater generators and transmission cables. The behavioral responses of common freshwater fishes to static and variable electromagnetic fields (EMF) that may be emitted by hydrokinetic projects were evaluated in laboratory experiments. Various fish species were exposed to either static (DC) EMF fields created by a permanent bar magnet or variable (AC) EMF fields created by a switched electromagnet for 48 h, fish locations were recorded with a digital imaging system, and changes in activity level and distribution relative to the magnet position were quantified at 5-min intervals. Experiments with fathead minnows, redear sunfish, striped bass, lake sturgeon, and channel catfish produced mixed results. Except for fathead minnows there was no effect on activity level. Only redear sunfish and channel catfish exhibited a change in distribution relative to the position of the magnet with an apparent attraction to the EMF source. In separate experiments, rapid behavioral responses of paddlefish and lake sturgeon to onset of the AC field were recorded with high-speed video. Paddlefish did not react to a variable, 60-Hz magnetic field like that which would be emitted by an AC generator or cable, but lake sturgeon consistently responded to the variable, AC-generated magnetic field with a variety of altered swimming behaviors. These results will be useful for determining under what circumstances cables or generators need to be positioned to minimize interactions with sensitive species.
Bevelhimer, Mark S [ORNL; Cada, Glenn F [ORNL; Fortner, Allison M [ORNL; Schweizer, Peter E [ORNL; Riemer, Kristina P [ORNL
Manifestation of a nonclassical Berry phase of an electromagnetic field in atomic Ramsey interference
The Berry phase acquired by an electromagnetic field undergoing an adiabatic and cyclic evolution in phase space is a purely quantum-mechanical effect of the field. However, this phase is usually accompanied by a dynamical contribution and cannot be manifested in any light-beam interference experiment because it is independent of the field state. We here show that such a phase can be produced using an atom coupled to a quantized field and driven by a slowly changing classical field, and it is manifested in atomic Ramsey interference oscillations. We also show how this effect may be applied to one-step implementation of multiqubit geometric phase gates, which is impossible by previous geometric methods. The effects of dissipation and fluctuations in the parameters of the pump field on the Berry phase and visibility of the Ramsey interference fringes are analyzed.
Shi-Biao Zheng
Zheng, Shi-Biao
Photon-radion conversion cross-sections in external electromagnetic field
An attempt is made to present some experimental predictions of the Randall-Sundrum model, where compactification radius of the extra dimension is stabilized by the radion, which is a scalar field lighter than the graviton Kaluza-Klein states. We calculate the conversion cross-sections of the photons into the radions in the external electromagnetic fields, namely, in the static fields and in a periodic field of the wave guide. Numerical evaluations of the total cross-sections are also given. Our result shows that the conversion cross-section in the static electric field is quite small. But, in the static magnetic and periodic fields, the radion productions are much enhanced.
Dong, P V; Soa, D V; Thao, N H; 10.1007/JHEP10(2011)018
P. V. Dong; H. N. Long; D. V. Soa; N. H. Thao
External control of ion waves in a plasma by high frequency fields
An apparatus and method are described for stabilizing plasma instabilities, in a magnetically confined plasma column by transmitting into the plasma high frequency electromagnetic waves at a frequency close to the electron plasma frequency. The said frequencies, e.g., are between the plasma frequency and 1.5 times the plasma frequency at a power level below the level for producing parametric instabilities in a plasma having temperatures from below 10 eV to about 10 keV or more, at densities from below 10/sup 13/ to above 10/sup 18/ particles/cm/sup 3/. (Official Gazette)
Kaw, P.K.; Dawson, J.M.
Low frequency electrostatic and electromagnetic modes of ultracold magnetized nonuniform dense plasmas
A coupled linear dispersion relation for the basic electrostatic and electromagnetic waves in the ultracold nonuniform magnetized dense plasmas has been obtained which interestingly is analogous to the classical case. The scales of macroscopic phenomena and the interparticle quantum interactions are discussed. It is important to point out that hydrodynamic models cannot take into account strong quantum effects and they are not applicable to very dense plasmas. The analysis is presented with applications to dense plasmas which are relevant to both laboratory and astrophysical environments.
Saleem, H. [National Centre for Physics (NCP), Quaid-i-Azam University Campus, Islamabad (Pakistan); Department of Physics, COMSATS Institute of Information Technology (CIIT), Islamabad (Pakistan); Ahmad, Ali [Department of Physics, COMSATS Institute of Information Technology (CIIT), Islamabad (Pakistan); Theoretical Plasma Physics Division, Pakistan Institute of Nuclear Science and Technology (PINSTECH), Islamabad (Pakistan); Khan, S. A. [National Centre for Physics (NCP), Quaid-i-Azam University Campus, Islamabad (Pakistan); Department of Physics, COMSATS Institute of Information Technology (CIIT), Islamabad (Pakistan); Department of Physics, Government College Bagh AJK (Pakistan)
On the Strong Coupling Limit of Many-Polaron Systems in Electromagnetic Fields
In this paper estimates on the ground state energy of Fr\\"ohlich $N$-polarons in electromagnetic fields in the strong coupling limit, $\\alpha\\to\\infty$, are derived. It is shown that the ground state energy is given by $\\alpha^2$ multiplied by the minimal energy of the corresponding Pekar-Tomasevich functional for $N$ particles, up to an error term of order $\\alpha^{42/23}N^3$. The potentials $A,V$ are suitably rescaled in $\\alpha$. As a corollary, binding of $N$-polarons for strong magnetic fields for large coupling constants is established.
David Wellig
Non-minimal $R^\\beta F^2$-Coupled Electromagnetic Fields to Gravity and Static, Spherically Symmetric Solutions
We investigate non-minimal $R^\\beta F^2$-type couplings of electromagnetic fields to gravity. We derive the field equations by a first order variational principle using the method of Lagrange multipliers. Then we present various static, spherically symmetric solutions describing the exterior fields in the vicinity of electrically charged massive bodies.
Dereli, Tekin
Thermodynamics of a quantized electromagnetic field in rectangular cavities with perfectly conducting walls
The thermodynamical properties of a quantized electromagnetic field inside a box with perfectly conducting walls are studied using a regularization scheme that permits to obtain finite expressions for the thermodynamic potentials. The source of ultraviolet divergences is directly isolated in the expression for the density of modes, and the logarithmic infrared divergences are regularized imposing the uniqueness of vacuum and, consequently, the vanishing of the entropy in the limit of zero temperature. We thus obtain corrections to the Casimir energy and pressures, and to the specific heat that are due to temperature effects; these results suggest effects that could be tested experimentally.
R. Jauregui; C. Villarreal; S. Hacyan
Three-dimensional electromagnetic strong turbulence. I. Scalings, spectra, and field statistics
The first fully three-dimensional (3D) simulations of large-scale electromagnetic strong turbulence (EMST) are performed by numerically solving the electromagnetic Zakharov equations for electron thermal speeds {nu}{sub e} with {nu}{sub e}/c{>=}0.025. The results of these simulations are presented, focusing on scaling behavior, energy density spectra, and field statistics of the Langmuir (longitudinal) and transverse components of the electric fields during steady-state strong turbulence, where multiple wave packets collapse simultaneously and the system is approximately statistically steady in time. It is shown that for {nu}{sub e}/c > or approx. 0.17 strong turbulence is approximately electrostatic and can be explained using the electrostatic two-component model. For v{sub e}/c > or approx. 0.17 the power-law behaviors of the scalings, spectra, and field statistics differ from the electrostatic predictions and results because {nu}{sub e}/c is sufficiently high to allow transverse modes to become trapped in density wells. The results are compared with those of past 3D electrostatic strong turbulence (ESST) simulations and 2D EMST simulations. For number density perturbations, the scaling behavior, spectra, and field statistics are shown to be only weakly dependent on {nu}{sub e}/c, whereas the Langmuir and transverse scalings, spectra, and field statistics are shown to be strongly dependent on {nu}{sub e}/c. Three-dimensional EMST is shown to have features in common with 2D EMST, such as a two-component structure and trapping of transverse modes which are dependent on {nu}{sub e}/c.
Graham, D. B.; Robinson, P. A.; Cairns, Iver H. [School of Physics, University of Sydney, New South Wales 2006 (Australia); Skjaeraasen, O. [ProsTek, Institute for Energy Technology, P.O. Box 40, N-2027 Kjeller (Norway)
Long-term monitoring of ULF electromagnetic fields at Parkfield, CA
Electric and magnetic fields in the (10{sup -4}-1.0) Hz band were monitored at two sites adjacent to the San Andreas Fault near Parkfield and Hollister, California from 1995 to present. A data window [2002-2005], enclosing the September 28, 2004 M6 Parkfield earthquake, was analyzed to determine if anomalous electric or magnetic fields, or changes in ground conductivity, occurred before the earthquake. The data were edited, removing intervals of instrument malfunction leaving 875 days in the four-year period. Frequent, spike-like disturbances were common, but were not more frequent around the time of the earthquake; these were removed before subsequent processing. Signal to noise amplitude spectra, estimated via magnetotelluric processing showed the behavior of the ULF fields to be remarkably constant over the period of analysis. These first-order plots make clear that most of the recorded energy is coherent over the spatial extent of the array. Three main statistical techniques were employed to separate local anomalous electrical or magnetic fields from the dominant coherent natural fields: transfer function estimates between components at each site were employed to subtract the dominant field, and look deeper at the 'residual' fields; the data were decomposed into principal components to identify the dominant coherent array modes; and the technique of canonical coherences was employed to distinguish anomalous fields which are spatially broad from anomalies which occur at a single site only, and furthermore to distinguish anomalies which are present in both the electric and magnetic fields from those which are present in only one field type. Standard remote reference apparent resistivity estimates were generated daily at Parkfield. A significant seasonal component of variability was observed suggesting local distortion due to variations in near surface resistance. In all cases, high levels of sensitivity to subtle electromagnetic effects were demonstrated, but no effects which can be reasonably characterized as precursors to the Parkfield earthquake were found.
Kappler, K.N.; Morrison, H.F.; Egbert, G.D.
Source-free electromagnetism's canonical fields reveal the free-photon Schroedinger equation
Classical equations of motion that are first-order in time and conserve energy can only be quantized after their variables have been transformed to canonical ones, i.e., variables in which the energy is the system's Hamiltonian. The source-free version of Maxwell's equations is purely dynamical, first-order in time and has a well-defined nonnegative conserved field energy, but is decidedly noncanonical, an issue that has attracted little attention. The opposite parities of the electric and magnetic fields and consequent curl operations that typify Maxwell's equations are especially at odds with their being canonical fields. Transformation of the magnetic field into the transverse part of the vector potential helps but is not sufficient; further simple nonnegative symmetric integral transforms, which commute with all differential operators, are needed for both fields; such transforms also supplant the curls in the equations of motion. The canonical replacements of the source-free electromagnetic fields remain transverse-vector fields, but are more diffuse than their predecessors. Combined as the real and imaginary parts of a complex field, the canonical fields prove to be the transverse-vector wave function of a time-dependent Schroedinger equation whose Hamiltonian operator is the quantization of the free photon's square-root relativistic energy. Thus proper quantization of the source-free Maxwell equations is identical to second quantization of free photons that have normal square-root energy. There is no physical reason why first and second quantization of any relativistic free particle ought not to proceed in precise parallel, utilizing the square-root Hamiltonian operator. This natural procedure leaves no role for the completely artificial Klein-Gordon and Dirac equations, as accords with their grossly unphysical properties.
Steven Kenneth Kauffmann
Regarding the Comments on "Near-field interference for the unidirectional excitation of electromagnetic guided modes" by Lee et al. [arXiv:1306.5068
Regarding the Comments on "Near-field interference for the unidirectional excitation of electromagnetic guided modes" by Lee et al. [arXiv:1306.5068 (2013)].
Rodr�guez-Fortu�o, Francisco J; Ginzburg, Pavel; O'Connor, Daniel; Mart�nez, Alejandro; Wurtz, Gregory A; Zayats, Anatoly V
Low-cost electromagnetic tagging : design and implementation
Several implementations of chipless RFID (Radio Frequency Identification) tags are presented and discussed as low-cost alternatives to chip-based RFID tags and sensors. An overview of present-day near-field electromagnetic ...
Fletcher, Richard R. (Richard Ribon)
Superluminal Electromagnetic and Gravitational Fields Generated in the Nearfield of Dipole Sources
In this paper the fields generated by an electric dipole and a gravitational quadrapole are shown to propagate superluminally in the nearfield of the source and reduce to the speed of light as the fields propagate into the farfield. A theoretical derivation of the generated fields using Maxwell's equations is presented followed by a theoretical analysis of the phase and group speed of the propagating fields. This theoretical prediction is then verified by a numerical simulation which demonstrates the superluminal propagation of modulated signals in the nearfield of their sources. An experiment using simple dipole antennas is also presented which verifies the theoretically expected superluminal propagation of transverse electromagnetic fields in the nearfield of the source. The phase speed, group speed, and information speed of these systems are compared and shown to differ. Provided the noise of a signal is small and the modulation method is known, it is shown that the information speed can be approximately the same as the superluminal group speed. According to relativity theory, it is known that between moving reference frames, superluminal signals can propagate backwards in time enabling violations of causality. Several explanations are presented which may resolve this dilemma.
William D. Walker
Detection of electromagnetic waves using charged MEMS structures
We describe micromechanical structures that are capable of sensing both electrostatic fields and electromagnetic fields over a wide frequency range. Typically, sensing of electromagnetic waves is achieved with electrically conducting antennas, which despite the many advantages do not exhibit high sensitivity over a broad frequency range. An important aspect of our present work is that, in contrast to traditional antennas, the dimensions of micromechanical oscillators sensitive to electromagnetic waves can be much smaller than the wavelength. We characterized the micromechanical oscillators and measured responses to electric fields and estimated the performance limits by evaluating the signal-to-noise ratio theoretically and experimentally.
Datskos, Panos G [ORNL; Lavrik, Nickolay V [ORNL; Tobin, Jacob D [ORNL; Bowland, Landon T [ORNL
Two-slit diffraction with highly charged particles: Niels Bohr's consistency argument that the electromagnetic field must be quantized
We analyze Niels Bohr's proposed two-slit interference experiment with highly charged particles that argues that the consistency of elementary quantum mechanics requires that the electromagnetic field must be quantized. In the experiment a particle's path through the slits is determined by measuring the Coulomb field that it produces at large distances; under these conditions the interference pattern must be suppressed. The key is that as the particle's trajectory is bent in diffraction by the slits it must radiate and the radiation must carry away phase information. Thus the radiation field must be a quantized dynamical degree of freedom. On the other hand, if one similarly tries to determine the path of a massive particle through an inferometer by measuring the Newtonian gravitational potential the particle produces, the interference pattern would have to be finer than the Planck length and thus undiscernable. Unlike for the electromagnetic field, Bohr's argument does not imply that the gravitational field must be quantized.
Gordon Baym; Tomoki Ozawa
We analyze Niels Bohr's proposed two-slit interference experiment with highly charged particles that argues that the consistency of elementary quantum mechanics requires that the electromagnetic field must be quantized. In the experiment a particle's path through the slits is determined by measuring the Coulomb field that it produces at large distances; under these conditions the interference pattern must be suppressed. The key is that as the particle's trajectory is bent in diffraction by the slits it must radiate and the radiation must carry away phase information. Thus the radiation field must be a quantized dynamical degree of freedom. On the other hand, if one similarly tries to determine the path of a massive particle through an inferometer by measuring the Newtonian gravitational potential the particle produces, the interference pattern would have to be finer than the Planck length and thus undiscernable. Unlike for the electromagnetic field, Bohr's argument does not imply that the gravitational field ...
Baym, Gordon; 10.1073/pnas.0813239106
Electromagnetic and gravitational self-force on a relativistic particle from quantum fields in curved space
We provide a quantum field theoretical derivation of the Abraham-Lorentz-Dirac (ALD) equation, describing the motion of an electric point charge sourcing an electromagnetic field, which back-reacts on the charge as a self-force, and the Mino-Sasaki-Tanaka-Quinn-Wald (MSTQW) equation describing the motion of a point mass with self-force interacting with the linearized metric perturbations caused by the mass off an otherwise vacuous curved background spacetime. We regularize the formally divergent self-force by smearing the direct part of the retarded Green's function and using a quasilocal expansion. We also derive the ALD-Langevin and the MSTQW-Langevin equations with a classical stochastic force accounting for the effect of the quantum fluctuations in the field, which causes small fluctuations on the particle trajectory. These equations will be useful for studying the stochastic motion of charges and small masses under the influence of both quantum and classical noise sources, derived either self-consistently or put in by hand phenomenologically. We also show that history-dependent noise-induced drift motions could arise from such stochastic sources on the trajectory that could be a hidden feature of gravitational wave forms hitherto unknown.
Chad R. Galley; B. L. Hu; Shih-Yuin Lin
Analytical time domain electromagnetic field propagators and closed-form solutions for transmission lines
An analytical solution for the coupled telegrapher�s equations in terms of the voltage and current on a homogeneous lossy transmission line and multiconductor transmission line is presented. The resulting telegrapher�s equation solution is obtained in the form of an exact time domain propagator operating on the line voltage and current. It is shown that the analytical equations lead to a stable numerical method that can be used in the analysis of both homogeneous and inhomogeneous transmission lines. A numerical dispersion relation is derived proving that this method has no numerical dispersion down to the two points per wavelength Nyquist limit. Examples are presented showing that exceptionally accurate results are obtained for lossy single and multiconductor transmission lines. The method is extended to represent the general solution to Maxwell�s differential equations in vector matrix form. It is shown that, given the electromagnetic field and boundary conditions at a given instant in time, the free space time domain propagator and corresponding dyadic Green�s functions in 1-, 2-, and 3-dimensions can be used to calculate the field at all subsequent times.
Jeong, Jaehoon
Superposition Principle and the Problem of the Additivity of the Energies and Momenta of Distinct Electromagnetic Fields
In this paper we prove in a rigorous mathematical way (using the Clifford bundle formalism) that the energies and momenta of two distinct and arbitrary free Maxwell fields (of finite energies and momenta) that are superposed are additive and thus that there is no incompatibility between the principle of superposition of fields and the principle of energy-momentum conservation, contrary to some recent claims. Our proof depends on a noticeable formula for the energy-momentum 1-form fields T^{a},namely Riesz formula, which is valid for any electromagnetic field configuration F satisfying Maxwell equation.
Eduardo Notte-Cuello; Waldyr A. Rodrigues Jr
Simply Amusing Algebra and Analysis or Electromagnetic and Gravitational Fields in the Single System of Equations
In this article the algebra and the basis of corresponding analysis in 4-dimensional spaces are constructed, in pseudoeuclidean with signature (1, -1, -1, -1) and pseudo-Riemannian corresponding to the real space-time. In both cases the analogues of Cauchy-Riemann conditions are obtained. They are the systems of 1-st order partial differential equations, linear for the pseudoeuclidean and quasi-linear for the pseudo-Riemannian space (linear as about the components of differentiable function ant its derivatives so about the derivatives of metric tensor). The general solution for pseudoeuclidean space which is the flat waves of components of dependent function, and special (spherical-symmetric) wave-like (as for the components of differentiable function so for the components of metric tensor) solution for the pseudo-Riemannian space are got. In the last case the absence of central singularity for the components of metric tensor is interesting. From the Cauchy-Riemann condition follows that the differentiable function is constant along some isotropic curves given by 1-st order differential equations. The demand these curves to be geodetic lines leads to the differential restrictions for the metric tensor itself. The special kind of these restrictions is obtained. The hypothesis that the differentiable function can be interpreted as an electromagnetic field is expressed.
D. M. Volokitin
Pilot Study of Nonresidential Power Frequency Magnetic Fields
EPRI has initiated several research projects to investigate magnetic field levels, their characteristics, and their sources. This report describes nonresidential magnetic field measurement protocols and instrumentation that can be used to identify and measure magnetic field sources in a variety of settings, including schools, offices, and electric utility facilities.
Apparatus and method for enhanced chemical processing in high pressure and atmospheric plasmas produced by high frequency electromagnetic waves
An apparatus and method for creating high temperature plasmas for enhanced chemical processing of gaseous fluids, toxic chemicals, and the like, at a wide range of pressures, especially at atmospheric and high pressures includes an electro-magnetic resonator cavity, preferably a reentrant cavity, and a wave guiding structure which connects an electro-magnetic source to the cavity. The cavity includes an intake port and an exhaust port, each having apertures in the conductive walls of the cavity sufficient for the intake of the gaseous fluids and for the discharge of the processed gaseous fluids. The apertures are sufficiently small to prevent the leakage of the electro-magnetic radiation from the cavity. Gaseous fluid flowing from the direction of the electro-magnetic source through the guiding wave structure and into the cavity acts on the plasma to push it away from the guiding wave structure and the electro-magnetic source. The gaseous fluid flow confines the high temperature plasma inside the cavity and allows complete chemical processing of the gaseous fluids at a wide range of pressures.
Efthimion, Philip C. (Bedminister, NJ); Helfritch, Dennis J. (Flemington, NJ)
ARM - Field Campaign - 2001 Multi-Frequency Radar IOP
govCampaigns2001 Multi-Frequency Radar IOP govCampaigns2001 Multi-Frequency Radar IOP Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Campaign : 2001 Multi-Frequency Radar IOP 2001.03.01 - 2001.09.30 Lead Scientist : Stephen Sekelsky Data Availability http://abyss.ecs.umass.edu For data sets, see below. Summary Install UMass and NOAA Aeronomy Laboratory "guest instrument" radars at the SGP CART site adjacent to the MMCR system. Both the UMass and NOAA Aeronomy Laboratory systems will run autonomously for approximately a six month period. Description Scientific hypothesis: A. Measurements from the University of Massachusetts (UMass) Cloud Profiling Radar System (CPRS) - 95/33 GHz Radar indicate that the 95 GHz channel is much less sensitive to insect clutter than the 35 GHz channel by
Approach on the high frequency electromagnetic field effects on human blood
Applications of microwave have been increased in the last years due to radars and police communication systems, high power satellite and TV transmitters, mobile phones, microwave ovens and medical devices. Exposure to microwave emissions has a negative ... Keywords: biological effects, exposure to microwave emissions, microscope analysis, modeling, simulation, ultrastructure of the human blood
Marius A. Silaghi; Ulrich L. Rohde; Ovidiu C. Fratila; Helga Silaghi; Tiberia Ioana Ilias
Since 1980, under the grant DEFG02-96ER40949, the Department of Energy has supported the educational and research work of the University of Maryland Dynamical Systems and Accelerator Theory (DSAT) Group. The primary focus of this educational/research group has been on the computation and analysis of charged-particle beam transport using Lie algebraic methods, and on advanced methods for the computation of electromagnetic fields and multiparticle phenomena. This Final Report summarizes the accomplishments of the DSAT Group from its inception in 1980 through its end in 2011.
Alex J. Dragt
Comments on "Near-field interference for the unidirectional excitation of electromagnetic guided modes"
Rodriguez-Fortuno et al. (19 April 2013, p. 330) reported the unidirectional excitation of electromagnetic guided modes via the oblique illumination of a circularly polarized light. This comment points out that the same scheme was addressed in our a-year-ahead paper and that magnetic dipoles play a key role in the unidirectional excitation which was neglected in Rodriguez-Fortuno et al.'s report.
Lee, Seung-Yeol; Kim, Kyoung-Youm; Lee, Byoungho
Power System Electromagnetic Compatibility
The potential for man-made electromagnetic interference has existed since the construction of the first electric power system. As the use of electricity expanded during the first few decades of the twentieth century, the number of sources of electromagnetic interference, as well as the number of receptors, burgeoned. With the proliferation of sources and receptors, the engineering study of electromagnetic interference--sometimes called radio noise, electrical noise, or radio-frequency interference--becam...
Spin relaxation and linear-in-electric-field frequency shift in an arbitrary, time-independent magnetic field
A method is presented to calculate the spin relaxation times T{sub 1}, T{sub 2} due to a nonuniform magnetic field, and the linear-in-electric-field precession frequency shift {delta}{omega}{sub E} when an electric field is present, in the diffusion approximation for spins confined to a rectangular cell. It is found that the rectangular cell geometry admits of a general result for T{sub 1}, T{sub 2}, and {delta}{omega}{sub E} in terms of the spatial cosine-transform components of the magnetic field.
Clayton, Steven Michael [Los Alamos National Laboratory
Interpretation of electromagnetic soundings in the Raft River geothermal
Interpretation of electromagnetic soundings in the Raft River geothermal Interpretation of electromagnetic soundings in the Raft River geothermal area, Idaho Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Report: Interpretation of electromagnetic soundings in the Raft River geothermal area, Idaho Details Activities (1) Areas (1) Regions (0) Abstract: An electromagnetic (EM) controlled source survey was conducted in the Raft River Valley, near Malta, Idaho. The purpose of the survey was: to field test U.S. Geological Survey extra-low-frequency (ELF) equipment using a grounded wire source and receiver loop configuration (which is designed to measure the vertical magnetic field (Hz) at the loop center for various frequencies); to present an example of the EM sounding data and interpretations using a previously developed inversion program; and (3) to
Electromagnetic Soundings At Raft River Geothermal Area (1977) | Open
Electromagnetic Soundings At Raft River Geothermal Area (1977) Electromagnetic Soundings At Raft River Geothermal Area (1977) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Electromagnetic Soundings At Raft River Geothermal Area (1977) Exploration Activity Details Location Raft River Geothermal Area Exploration Technique Electromagnetic Sounding Techniques Activity Date 1977 Usefulness not indicated DOE-funding Unknown Exploration Basis The purpose of the survey was: (1) to field test U.S. Geological Survey extra-low-frequency (ELF) equipment using a grounded wire source and receiver loop configuration (which is designed to measure the vertical magnetic field (Hz) at the loop center for various frequencies); (2) to present an example of the EM sounding data and interpretations using a
The Covariant Electromagnetic Casimir Effect for Real Conducting Cylindrical Shells
Using covariant quantization of the electromagnetic field, the Casimir force per unit area experienced by a long conducting cylindrical shell, under both Dirichlet and Neumann boundary conditions, is calculated. The renormalization procedure is based on the plasma cut-off frequency for real conductors. The real case of a gold (silver) cylindrical shell is considered and the corresponding electromagnetic Casimir pressure is computed. It is discussed that the Dirichlet and Neumann problems should be considered separately without adding their corresponding results.
H. Razmi; N. Fadaei
Medical Devices: Electromagnetic Interference Status and the Role of Standards
This technical update discusses the role of voluntary and regulatory standards in determining the risks of interference from electric and magnetic fields (EMF) with the functioning of implantable and wearable medical devices. The update covers frequencies from the extremely low frequency (ELF) range through the radio-frequency (RF) range. It augments a 2008 EPRI technical update on electromagnetic interference (EMI) with newer types of implanted medical devices (1016815) and previous EPRI publications th...
Noninvasive valve monitor using constant magnetic and/or DC electromagnetic field
One or more sources of steady magnetic field are carefully located on the outside of a valve body. The constant magnetic field is transmitted into the valve body and valve internals. A magnetic field detector carefully located on the outside of the valve body detects the intensity of the magnetic field at its location. As the position of a valve internal part is changed, there is an alteration in the magnetic field in the valve, and a consequent change in the detected magnetic field. Changes in the detected signal provide an indication of the position and motion of the valve internals.
Casada, D.A.; Haynes, H.D.
Casada, Donald A. (Knoxville, TN); Haynes, Howard D. (Knoxville, TN)
Path planning and position control and of an underactued [sic] electromagnetic formation flight satellite system in the near field
Electromagnetic formation flight is the process of using electromagnetic actuators (coils) on multiple spacecraft to produce relative (internal) forces in order to control the relative position and orientation of the ...
Buck, Alexander J. (Alexander James), 1989-
Influence on electron coherence from quantum electromagnetic fields in the presence of conducting plates
The influence of electromagnetic vacuum fluctuations in the presence of the perfectly conducting plate on electrons is studied with an interference experiment. The evolution of the reduced density matrix of the electron is derived by the method of influence functional. We find that the plate boundary anisotropically modifies vacuum fluctuations that in turn affect the electron coherence. The path plane of the interference is chosen either parallel or normal to the plate. In the vicinity of the plate, we show that the coherence between electrons due to the boundary is enhanced in the parallel configuration, but reduced in the normal case. The presence of the second parallel plate is found to boost these effects. The potential relation between the amplitude change and phase shift of interference fringes is pointed out. The finite conductivity effect on electron coherence is discussed.
Jen-Tsung Hsiang; Da-Shin Lee
Waveguide-based ultrasonic and far-field electromagnetic sensors for downhole reservoir characterization.
This report summarizes the first year research and development effort leading to development of high-temperature sensors for enhanced geothermal systems. It covers evaluation of ultrasonic and electromagnetic (EM) techniques applied to temperature measurement and flow characterization. On temperature measurement, we have evaluated both microwave radiometry and ultrasonic techniques for temperature gradient and profile measurements. Different antenna designs are evaluated and array loop antenna design is selected for further development. We have also evaluated ultrasonic techniques for total flow characterization, which includes using speed of sound to determine flow temperature, measuring acoustic impedance to estimate fluid density, and using cross-correlation technique to determine the mass flow rate. Method to estimate the flow enthalpy is briefly discussed. At end, the need and proposed techniques to characterize the porosity and permeability of a hot dry rock resource are presented.
Sheen, S. H.; Chien, H. T.; Wang, K.; Liao, S.; Gopalsami, N.; Bakhtiari, S.; Raptis, A. C.; Nuclear Engineering Division
Electron random walk and collisional crossover in a gas in presence of electromagnetic waves and magnetostatic fields
This paper deals with random walk of electrons and collisional crossover in a gas evolving toward a plasma, in presence of electromagnetic (EM) waves and magnetostatic (B) fields, a fundamental subject of importance in areas requiring generation and confinement of wave assisted plasmas. In presence of EM waves and B fields, the number of collisions N suffered by an electron with neutral gas atoms while diffusing out of the volume during the walk is significantly modified when compared to the conventional field free square law diffusion; N=1.5({Lambda}/{lambda}){sup 2}, where {Lambda} is the characteristic diffusion length and {lambda} is the mean free path. There is a distinct crossover and a time scale associated with the transition from the elastic to inelastic collisions dominated regime, which can accurately predict the breakdown time ({tau}{sub c}) and the threshold electric field (E{sub BD}) for plasma initiation. The essential features of cyclotron resonance manifested as a sharp drop in {tau}{sub c}, lowering of E{sub BD} and enhanced electron energy gain is well reproduced in the constrained random walk.
Bhattacharjee, Sudeep; Paul, Samit [Department of Physics, Indian Institute of Technology, Kanpur 208016, Uttar Pradesh (India); Dey, Indranuj [Kyushu University, Kasuga Kouen 6-1, Kasuga City, 816-8580 (Japan)
The two-nucleon electromagnetic charge operator in chiral effective field theory ($\\chi$EFT) up to one loop
The electromagnetic charge operator in a two-nucleon system is derived in chiral effective field theory ($\\chi$EFT) up to order $e\\, Q$ (or N4LO), where $Q$ denotes the low-momentum scale and $e$ is the electric charge. The specific form of the N3LO and N4LO corrections from, respectively, one-pion-exchange and two-pion-exchange depends on the off-the-energy-shell prescriptions adopted for the non-static terms in the corresponding potentials. We show that different prescriptions lead to unitarily equivalent potentials and accompanying charge operators. Thus, provided a consistent set is adopted, predictions for physical observables will remain unaffected by the non-uniqueness associated with these off-the-energy-shell effects.
S. Pastore,L. Girlanda,R. Schiavilla,M. Viviani,S. Pastore,L. Girlanda,R. Schiavilla,M. Viviani
Two-nucleon electromagnetic charge operator in chiral effective field theory ({chi}EFT) up to one loop
The electromagnetic charge operator in a two-nucleon system is derived in chiral effective field theory ({chi}EFT) up to order e Q[or next-to-next-to-next-to-next-to-leading order (N4LO)], where Q denotes the low-momentum scale and e is the electric charge. The specific form of the N3LO and N4LO corrections from, respectively, one-pion-exchange and two-pion-exchange depends on the off-the-energy-shell prescriptions adopted for the nonstatic terms in the corresponding potentials. We show that different prescriptions lead to unitarily equivalent potentials and accompanying charge operators. Thus, provided a consistent set is adopted, predictions for physical observables will remain unaffected by the nonuniqueness associated with these off-the-energy-shell effects.
Pastore, S. [Physics Division, Argonne National Laboratory, Illinois 60439 (United States); Girlanda, L. [Department of Physics, Universita del Salento, I-73100 Lecce (Italy); INFN Sezione di Lecce, I-73100 Lecce (Italy); Schiavilla, R. [Department of Physics, Old Dominion University, Norfolk, Virginia 23529 (United States); Jefferson Lab, Newport News, Virginia 23606 (United States); Viviani, M. [INFN Sezione di Pisa, I-56127 Pisa (Italy)
The ??? Amplitude in an External Homogeneous Electromagnetic
Neutrino-photon interactions in the presence of an external homogeneous constant electromagnetic field are studied. The ??? amplitude is calculated in an electromagnetic field of the general type, when the two field invariants are nonzero.
R. Shaisultanov
More about the hypothesis of a new weak interaction of electromagnetic field in the hidden sector
New hypothetical field equations (Eqs. (1) and (2)) are further discussed, unifying Maxwell's equations of the Standard Model (after the electroweak symmetry is spontaneously broken) with the dynamics of hidden sector (expected to be responsible for the cold dark matter). The hidden sector is represented by sterile spin-1/2 Dirac fermions ("sterinos") and sterile spin-0 bosons ("sterons") whose masses are spontaneously generated by a nonzero vacuum expectation value of the steron field, while sterino and steron interactions are mediated by sterile spin-1 quanta of an antisymmetric-tensor field with a large mass scale ("A bosons"). These interactions are presumed to be weak, but stronger than the universal gravity. Beside sterinos and sterons, the Standard-Model photons are included into the source of sterile A bosons and so, they become a link between the hidden and Standard-Model sectors ("photonic portal" to the hidden sector). The relativistic structure of antisymmetric-tensor field of sterile A bosons can be split into a vector and an axial three-dimensional fields (of spin 1 and parities - and +) in such a way that the Standard-Model electric and magnetic fields become involved separately in the sources of these two kinds of sterile A-boson radiation, respectively.
Wojciech Krolikowski
Electromagnetic Compatibility & Telecommunications
Directory of Accredited Laboratories. Electromagnetic Compatibility & Telecommunications. The Electromagnetic Compatability ...
Characterization of the reactive flow field dynamics in a gas turbine injector using high frequency PIV
The present work details the analysis of the aerodynamics of an experimental swirl stabilized burner representative of gas turbine combustors. This analysis is carried out using High Frequency PIV (HFPIV) measurements in a reactive situation. While this information is usually available at a rather low rate, temporally resolved PIV measurements are necessary to better understand highly turbulent swirled flows, which are unsteady by nature. Thanks to recent technical improvements, a PIV system working at 12 kHz has been developed to study this experimental combustor flow field. Statistical quantities of the burner are first obtained and analyzed, and the measurement quality is checked, then a temporal analysis of the velocity field is carried out, indicating that large coherent structures periodically appear in the combustion chamber. The frequency of these structures is very close to the quarter wave mode of the chamber, giving a possible explanation for combustion instability coupling.
Barbosa, S�verine; Ducruix, S�bastien
Hamiltonian theory of ponderomotive effects of an electromagnetic wave in a nonuniform magnetic field
Noncanonical variables are used to construct a Hamiltonian for guiding-center motion in a nonuniform magnetostatic field. Lie methods are then used to obtain the ponderomotive (quasistatic) Hamiltonian for the perturbation by a wave of arbitrary polarization and wavenumber, with spatially modulated amplitude and wavevector. The result is applied to the problem of r.f. stoppering in mirror confinement.
Grebogi, C.; Kaufman, A.N.; Littlejohn, R.G.
Probing the Magnetic Fields of Nearby Spiral Galaxies at Low Frequencies with LOFAR
While the Low Frequency Array (LOFAR) is still in its commissioning phase, early science results are starting to emerge. Two nearby galaxies, M51 and NGC4631, have been observed as part of the Magnetism Key Science Project's (MKSP) effort to increase our understanding of the nature of weak magnetic fields in galaxies. LOFAR and the complexity of its calibration as well as the aims and goals of the MKSP are presented.
Mulcahy, D D; Adebahr, B; Anderson, J; Beck, R; Bell, M R; Chyzy, K; Giessuebel, R; Heald, G; Horneffer, A; Jurusik, W; Pizzo, R; Scaife, A; Sotomayor-Beltran, C; Nikiel-Wroczynski, B
Electric dipole moment searches: Effect of linear electric field frequency shifts induced in confined gases, II
The next generation of particle edm searches will be at such a high sensitivity that it will be possible for the results to be contaminated by a systematic error resulting from the interaction of the motional (E x v/c) magnetic field with stray field gradients. In this paper we extend previous work to present an analytic form for the frequency shift in the case of a rectangular storage vessel and discuss the implications of the result for the neutron edm experiment which will be installed at the SNS (Spallation Neutron Source) by the LANL collaboration
R. Golub; C. M. Swank; S. K. Lamoreaux
Electromagnetics - DC/Low Frequency
... TN. Oak Ridge Metrology Center, Oak Ridge, TN [105000- 0] Oak Ridge National Laboratory - Metrology, Oak Ridge, TN [200659- 0] Transcat ...
... GA [200403- 0] ID. Idaho National Laboratory -Calibration Services Dept., Idaho Falls, ID [200115- 0] IL. S. Himmelstein ...
Effects of Detuning on Control of Intersubband Quantum Well Transitions with Chirped Electromagnetic Pulses
We study the interaction of a chirped electromagnetic pulse with intersubband transitions of a double semiconductor quantum well. We specifically consider the interaction of the ground and first excited subbands with the electromagnetic field and use the nonlinear density matrix equations for the description of the system dynamics. These equations are solved numerically for various values of the electron sheet density for a realistic double GaAs/AlGaAs quantum well, and the efficiency of population transfer is discussed with emphasis given to the effects of the detuning of the central frequency of the electromagnetic field from resonance.
Blekos, Konstantinos; Terzis, Andreas F. [Physics Department, School of Natural Sciences, University of Patras, Patras 265 04 (Greece); Simserides, Constantinos [Institute of Materials Science, National Center of Scientific Research Demokritos, 153 10 Athens (Greece); Paspalakis, Emmanuel [Materials Science Department, School of Natural Sciences, University of Patras, Patras 265 04 (Greece)
Problem of the decay instability of electromagnetic waves in a magnetoactive plasma
The processes of decay of transverse electromagnetic waves propagating across a constant magnetic field are considered. The possibility of using these decays for tuning the frequency of the stimulated radiation in the magnetoactive plasma of semiconductors, as well as for the diagnostics of the magnetic fields that spontaneously develop in a laser plasma is discussed.
Roslyakov, V.A.; Starostin, A.N.
Wavelet-like bases for thin-wire integral equations in electromagnetics
In this paper, wavelets are used in solving, by the method of moments, a modified version of the thin-wire electric field integral equation, in frequency domain. The time domain electromagnetic quantities, are obtained by using the inverse discrete fast ... Keywords: 02.30.Rz, 02.60.Cb, 02.70.-c, 41.20.-q, 41.20.Jb, M-band wavelet transform, Method of moments, Preconditioning, Thin-wire integral equations in electromagnetics
E. Francomano; A. Tortorici; E. Toscano; G. Ala; F. Viola
Nonlocal theory of electromagnetic wave decay into two electromagnetic waves in a rippled density plasma channel
Parametric decay of a large amplitude electromagnetic wave into two electromagnetic modes in a rippled density plasma channel is investigated. The channel is taken to possess step density profile besides a density ripple of axial wave vector. The density ripple accounts for the momentum mismatch between the interacting waves and facilitates nonlinear coupling. For a given pump wave frequency, the requisite ripple wave number varies only a little w.r.t. the frequency of the low frequency decay wave. The radial localization of electromagnetic wave reduces the growth rate of the parametric instability. The growth rate decreases with the frequency of low frequency electromagnetic wave.
Sati, Priti; Tripathi, V. K. [Indian Institute of Technology, Hauz Khas, Delhi 110054 (India)
Definition: Ground Electromagnetic Techniques | Open Energy Information
Definition Definition Edit with form History Facebook icon Twitter icon » Definition: Ground Electromagnetic Techniques Jump to: navigation, search Dictionary.png Ground Electromagnetic Techniques Ground electromagnetic techniques measure electromagnetic fields in order to determine subsurface electrical resistivity with the earth surface as the observation point.[1] View on Wikipedia Wikipedia Definition The electromagnetic force is one of the four fundamental interactions in nature, the other three being the strong interaction, the weak interaction, and gravitation. This force is described by electromagnetic fields, and has innumerable physical instances including the interaction of electrically charged particles and the interaction of uncharged magnetic force fields with electrical conductors. The word
TESLA Report 2003-10 Studies of Electromagnetic Cascade Showers Development in the TESLA Main Linac Initiated by Electron Field Emission in RF Cavities
this paper, and, in order to see this point more clearly, none of the other possible particle multiplication processes will be included in our simulations. 2 Simulation Procedure and Code Design The process of particle transport in our computer code DUST (DUnkel STrom, in German) is organized in such a way that it naturally breaks down into two parts, Monte Carlo simulation of the electromagnetic shower development when a particle impacts the inner vacuum surface of the accelerator, and particle dynamics in an electromagnetic field inside the accelerator vacuum. As usual, the accelerator to be studied is described as a sequence of physical elements. The user specifies the element geometry, materials and electromagnetic fields. And although we have not implemented something similar to the MAD [20] lattice description language yet, to simplify the accelerator description, elements in our program can be grouped into di#erent modules, from modules one constructs cells, and a sequence of cells forms the linac. 2.1 Particle Transport in Nonvacuum Media When an energetic primary particle incidents on a mass of material of su#cient thickness a cascade of particles and electromagnetic radiation of great complexity results, and the most practical way to obtain the characteristics of this cascade, the distribution and parameters of secondary particles, especially for complicated material geometries, is through Monte Carlo simulations. Even though a code for the transport of high energy particles (in GeV range) can be developed without too great complications (see, for example, [21], [22]), the accurate simulation of the low energy particles is a very demanding e#ort. So, it is obvious, that it is better to use a thoroughly tested, standard programme, based on an extensive and r...
Balandin Brinkmann Flottmann; V. Bal; R. Brinkmann; K. Fl�ttmann; N. Golubeva
Modeling Electromagnetic Reflectivity of Agbabu Oil Sand from Hyperspectral Infrared Reflectance Spectra and Dielectric Properties at L-, C- and X-Band Frequencies
In this paper remote identification of oil sand reservoirs from synthetic aperture radar (SAR) is enhanced by accurate modeling of the electromagnetic (EM) reflectivity of Agbabu oil sands. This is demonstrated using a novel combination of hyperspectral ... Keywords: EM Reflectivity, Computer Simulation, Agbabu Oil Sand, Dielectric property, Petroleum Exploration
Maurice Ezeoke, Kenneth Tong
The spinor field theory of the photon
I introduce a spinor field theory for the photon. The three-dimensional vector electromagnetic field and the four-dimensional vector potential are components of this spinor photon field. A spinor equation for the photon field is derived from Maxwell's equations,the relations between the electromagnetic field and the four-dimensional vector potential, and the Lorentz gauge condition. The covariant quantization of free photon field is done, and only transverse photons are obtained. The vacuum energy divergence does not occur in this theory. A covariant "positive frequency" condition is introduced for separating the photon field from its complex conjugate in the presence of the electric current and charge.
Ruo Peng Wang
This patent reiates to electromagnetic pumps for electricity-conducting fluids and, in particular, describes several modifications for a linear conduction type electromagnetic interaction pump. The invention resides in passing the return conductor for the current traversing the fiuid in the duct back through the gap in the iron circuit of the pump. Both the maximum allowable pressure and the efficiency of a linear conduction electromagnetic pump are increased by incorporation of the present invention.
Pulley, O.O.
Method for manufacturing compound semiconductor field-effect transistors with improved DC and high frequency performance
A method for making compound semiconductor devices including the use of a p-type dopant is disclosed wherein the dopant is co-implanted with an n-type donor species at the time the n-channel is formed and a single anneal at moderate temperature is then performed. Also disclosed are devices manufactured using the method. In the preferred embodiment n-MESFETs and other similar field effect transistor devices are manufactured using C ions co-implanted with Si atoms in GaAs to form an n-channel. C exhibits a unique characteristic in the context of the invention in that it exhibits a low activation efficiency (typically, 50% or less) as a p-type dopant, and consequently, it acts to sharpen the Si n-channel by compensating Si donors in the region of the Si-channel tail, but does not contribute substantially to the acceptor concentration in the buried p region. As a result, the invention provides for improved field effect semiconductor and related devices with enhancement of both DC and high-frequency performance.
Zolper, John C. (Vienna, VA); Sherwin, Marc E. (Rockville, MD); Baca, Albert G. (Albuquerque, NM)
Compound semiconductor field-effect transistors with improved dc and high frequency performance
A method for making compound semiconductor devices including the use of a p-type dopant is disclosed wherein the dopant is co-implanted with an n-type donor species at the time the n-channel is deposited. Also disclosed are devices manufactured using the method. In the preferred embodiment n-MESFETs and other similar field effect transistor devices are manufactured using C ions implanted with Si atoms in GaAs to form an n-channel. C exhibits a unique characteristic in the context of the invention in that it exhibits a low activation efficiency (typically, 50% or less) as a p-type dopant, and consequently, it acts to sharpen the Si n-channel by compensating Si donors in the region the Si-channel tail, but does not contribute substantially to the acceptor concentration in the region of the buried p-implant. As a result, the invention provides for improved field effect transistor devices with enhancement of both DC and high-frequency performance.
Zolper, J.C.; Sherwin, M.E.; Baca, A.G.
Topology optimization for the design of periodic microstructures composed of electromagnetic materials
Electromagnetic structures that incorporate certain structural periodicities are known to display special behavior when subjected to electromagnetic waves, and can be designed to have specific functions such as inhibiting the intrusion of electromagnetic ... Keywords: Electromagnetic field, Periodic boundary, Topology optimization
Tsuyoshi Nomura; Shinji Nishiwaki; Kazuo Sato; Koichi Hirayama
Comparison of coupling of humans to electric and magnetic fields with frequencies between 100 Hz and 100 kHz
Recent laboratory and epidemiological results have stimulated interest in the hypothesis that human beings may exhibit biological responses to magnetic and/or electric field transients with frequencies in the range between 100 Hz and 100 kHz. Much can be learned about the response of a system to a transient stimulation by understanding its response to sinusoidal disturbances over the entire frequency range of interest. Thus, the main effort of this paper was to compare the strengths of the electric fields induced in homogeneous ellipsoidal models by uniform 100 Hz through 100 kHz electric and magnetic fields. Over this frequency range, external electric fields of about 25--2,000 V/m (depending primarily on the orientation of the body relative to the field) are required to induce electric fields inside models of adults and children that are similar in strength to those induced by an external 1 {mu}T magnetic field. Additional analysis indicates that electric fields induced by uniform external electric and magnetic fields and by the nonuniform electric and magnetic fields produced by idealized point sources will not differ by more than a factor of two until the sources are brought close to the body. Published data on electric and magnetic field transients in residential environments indicate that, for most field orientations, the magnetic component will induce stronger electric fields inside adults and children than the electric component. This conclusion is also true for the currents induced in humans by typical levels of 60 Hz electric and magnetic fields in US residences.
Kaune, W.T. [EM Factors, Richland, WA (United States); Guttman, J.L. [Enertech Consultants, Campbell, CA (United States); Kavet, R. [Electric Power Research Inst., Palo Alto, CA (United States)
Advection, Phase Distortion, and the Frequency Spectrum of Finescale Fields in the Sea
Continuous depth�time measurements of upper-ocean velocity are used to estimate the wavenumber�frequency spectrum of shear. A fundamental characteristic of these spectra is that the frequency bandwidth increases linearly with increasing ...
Robert Pinkel
Electromagnetically induced interference at superconducting qubits
We study electromagnetically induced interference at superconducting qubits. The interaction between qubits and electromagnetic fields can provide additional coupling channels to qubit states, leading to quantum interference in a microwave driven qubit. In particular, the interwell relaxation or Rabi oscillation, resulting respectively from the multi- or single-mode interaction, can induce effective crossovers. The environment is modeled by a multi-mode thermal bath, generating the interwell relaxation. Relaxation induced interference, independent of the tunnel coupling, provides deeper understanding to the interaction between the qubits and their environment. It also supplies a useful tool to characterize the relaxation strength as well as the characteristic frequency of the bath. In addition, we demonstrate the relaxation can generate population inversion in a strongly driving two-level system. On the other hand, different from Rabi oscillation, Rabi oscillation induced interference involves more complicate...
Du, Lingjie
Tubular Radio Frequency (RF) Cage Field Confinement Cavity (IN-05-107)
Scientists at Argonne National Laboratory have created innovations in the design and fabrication of radio frequency (RF) cavities that improve ...
Electromagnetic Interference with Implanted Medical Devices: An Update
Electric and magnetic fields (EMF) and contact currents at both power and radio frequencies can interfere with the functioning of implanted medical electronic devices. In both public and occupational environments, electromagnetic interference issues are now exacerbated by the exponential increase in sources of interference over the last decade, an increasing variety of types of susceptible devices, and greater potential for unintended consequences that can be serious. This technical update discusses pote...
EPRI Comments on a Study of Power-Frequency Magnetic Fields and Childhood Brain Tumors in Japan
A paper entitled, "Power-Frequency Magnetic Fields and Childhood Brain Tumors: A Case-Control Study in Japan," was recently published in Journal of Epidemiology (2010;20(1):54-61). The authors reported finding a positive association between magnetic field exposures above 0.4 T and risk of childhood brain tumors. These EPRI comments evaluate the strengths and limitations of the epidemiologic study.
The influence of oscillating electromagnetic fields on membrane structure and function: Synthetic liposome and natural membrane bilayer systems with direct application to the controlled delivery of chemical agents
Investigations have been conducted to determine if an imposed electromagnetic field can influence membrane transport, and ion and drug permeability in both synthetic and natural cell membrane systems. Microwave fields enhance accumulation of sodium in the lymphocyte and induce protein shedding at Tc. Microwaves also trigger membrane permeability of liposome systems under specific field exposure conditions. Sensitivity varies in a defined way in bilayers displaying a membrane structural phase transition temperature, Tc; maximal release was observed at or near Tc. Significantly, liposome systems without a membrane phase transition were also found to experience permeability increases but, in contrast, this response was temperature independent. The above results indicate that field-enhanced drug release occurs in liposome vesicles that possess a Tc as well as non-Tc liposomes. Additional studies extend non-Tc liposome responses to the in vivo case in which microwaves trigger Gentamicin release from a liposome depot'' placed subcutaneously in the rat hind leg. In addition, evidence is provided that cell surface sequestered liposomes can be triggered by microwave fields to release drugs directly into target cells. 24 refs., 6 figs.
Liburdy, R.P.; de Manincor, D.; Fingado, B.
Radio-frequency measurements of UNiX compounds (X= Al, Ga, Ge) in high magnetic fields
We performed radio-frequency (RF) skin-depth measurements of antiferromagnetic UNiX compounds (X=Al, Ga, Ge) in magnetic fields up to 60 T and at temperatures between 1.4 to {approx}60 K. Magnetic fields are applied along different crystallographic directions and RF penetration-depth was measured using a tunnel-diode oscillator (TDO) circuit. The sample is coupled to the inductive element of a TDO resonant tank circuit, and the shift in the resonant frequency {Delta}f of the circuit is measured. The UNiX compounds exhibit field-induced magnetic transitions at low temperatures, and those transitions are accompanied by a drastic change in {Delta}f. The results of our skin-depth measurements were compared with previously published B-T phase diagrams for these three compounds.
Mielke, Charles H [Los Alamos National Laboratory; Mcdonald, David R [Los Alamos National Laboratory; Zapf, Vivien [Los Alamos National Laboratory; Altarawneh, Moaz M [Los Alamos National Laboratory; Lacerda, Alex H [Los Alamos National Laboratory; Adak, Sourav [Los Alamos National Laboratory; Karunakar, Kothapalli [Los Alamos National Laboratory; Nakotte, Heinrich [Los Alamos National Laboratory; Chang, S [NIST; Alsmadi, A M [HASHEMITE UNIV; Alyones, S [HASHEMIT UNIV
Superconducting dipole electromagnet
A dipole electromagnet of especial use for bending beams in particle accelerators is wound to have high uniformity of magnetic field across a cross section and to decrease evenly to zero as the ends of the electromagnet are approached by disposing the superconducting filaments of the coil in the crescent-shaped nonoverlapping portions of two intersecting circles. Uniform decrease at the ends is achieved by causing the circles to overlap increasingly in the direction of the ends of the coil until the overlap is complete and the coil is terminated.
Purcell, John R. (San Diego, CA)
H{sup -} beam extraction from a cesium seeded field effect transistor based radio frequency negative hydrogen ion source
H{sup -} beam was successfully extracted from a cesium seeded ion source operated using a field effect transistor inverter power supply as a radio frequency (RF) wave source. High density hydrogen plasma more than 10{sup 19} m{sup -3} was obtained using an external type antenna with RF frequency of lower than 0.5 MHz. The source was isolated by an isolation transformer and H{sup -} ion beam was extracted from a single aperture. Acceleration current and extraction current increased with the increase of extraction voltage. Addition of a small amount of cesium vapor into the source enhanced the currents.
Ando, A.; Matsuno, T.; Funaoi, T.; Tanaka, N. [School of Engineering, Tohoku University, Sendai 980-8579 (Japan); Tsumori, K.; Takeiri, Y. [National Institute for Fusion Science, Toki 509-5292 (Japan)
Definition: Electromagnetic Techniques | Open Energy Information
Electromagnetic Techniques Electromagnetic Techniques The objective of electromagnetic (EM) techniques is to image the electrical resistivity structure of the subsurface through the measurement of naturally- or artificially-generated electromagnetic fields.[1] View on Wikipedia Wikipedia Definition The electromagnetic force is one of the four fundamental interactions in nature, the other three being the strong interaction, the weak interaction, and gravitation. This force is described by electromagnetic fields, and has innumerable physical instances including the interaction of electrically charged particles and the interaction of uncharged magnetic force fields with electrical conductors. The word electromagnetism is a compound form of two Greek terms, ἢλεκτρον, ēlektron, "amber", and μαγνήτης, magnētēs, "magnet". The science
An integro-algebraic equation for high frequency wake fields in a tube with smoothly varying radius
A technique to find the longitudinal wake field at frequencies above or below the tube cut-off is described. The round tube is infinite in length, and has an arbitrary, smooth variation of radius over a finite interval. A system of integro-algebraic equations enforces the boundary conditions on the wall and the outgoing wave condition at infinity. The first step in an iterative solution of the system, valid for variations of tube radius with small derivative, yields a convenient formula for the impedance as a double integral. At low frequencies the formula gives Yokoya`s result plus corrections that can be large. For high frequencies in the case of several wall undulations it gives a sequence of finite-Q resonances. To avoid the limitations of the iterative method, a numerical solution of the system is carried out.
Warnock, R.L.
4D frequency analysis of computational cameras for depth of field extension
Depth of field (DOF), the range of scene depths that appear sharp in a photograph, poses a fundamental tradeoff in photography---wide apertures are important to reduce imaging noise, but they also increase defocus blur. Recent advances in computational ... Keywords: Fourier analysis, computational camera, depth of field, light field
Anat Levin; Samuel W. Hasinoff; Paul Green; Fr�do Durand; William T. Freeman
Three-dimensional transient electromagnetic modeling in the Laplace Domain
In modeling electromagnetic responses, Maxwell's equations in the frequency domain are popular and have been widely used (Nabighian, 1994; Newman and Alumbaugh, 1995; Smith, 1996, to list a few). Recently, electromagnetic modeling in the time domain using the finite difference (FDTD) method (Wang and Hohmann, 1993) has also been used to study transient electromagnetic interactions in the conductive medium. This paper presents a new technique to compute the electromagnetic response of three-dimensional (3-D) structures. The proposed new method is based on transforming Maxwell's equations to the Laplace domain. For each discrete Laplace variable, Maxwell's equations are discretized in 3-D using the staggered grid and the finite difference method (FDM). The resulting system of equations is then solved for the fields using the incomplete Cholesky conjugate gradient (ICCG) method. The new method is particularly effective in saving computer memory since all the operations are carried out in real numbers. For the same reason, the computing speed is faster than frequency domain modeling. The proposed approach can be an extremely useful tool in developing an inversion algorithm using the time domain data.
Mizunaga, H.; Lee, Ki Ha; Kim, H.J.
Physics 227 Winter, 1998 Problem Set 9 Due date: Monday, March 9 9.1 energy-momentum ratio A beam of moving particles, like an electromagnetic field, contains momentum
Physics 227 Winter, 1998 Problem Set 9 Due date: Monday, March 9 9.1 energy-momentum ratio A beam of moving particles, like an electromagnetic field, contains momentum and transports energy. a) Find the ratio of energy current to momentum density for a beam of particles with mass m and speed v. (The number
Witten, Thomas A.
Theoretical, Numerical, and Experimental Evidence of Superluminal Electromagnetic and Gravitational Fields Generated in the Nearfield of Dipole Sources
Theoretical and numerical wave propagation analysis of an oscillating electric dipole is presented. The results show that upon creation at the source, both the longitudinal electric and transverse magnetic fields propagate superluminally and reduce to the speed of light as they propagate about one wavelength from the source. In contrast, the transverse electric field is shown to be created about 1/4 wavelength outside the source and launches superluminal fields both towards and away from the source which reduce to the speed of light as the field propagates about one wavelength from the source. An experiment using simple dipole antennas is shown to verify the predicted superluminal transverse electric field behavior. In addition, it is shown that the fields generated by a gravitational source propagate superluminally and can be modeled using quadrapole electrodynamic theory. The phase speed, group speed, and information speed of these systems are compared and shown to differ. Provided the noise of a signal is small and the modulation method is known, it is shown that the information speed can be approximately the same as the superluminal group speed. According to relativity theory, it is known that between moving reference frames, superluminal signals can propagate backwards in time enabling violations of causality. Several explanations are presented which may resolve this dilemma.
Generation of electro-magnetic oscillation in surface multijunction MOMOM
An intergrated surface multijunction MOMOM (metal-oxide-metal-oxide-metal) is reported and coherent electromagnetic oscillation is observed in the low frequency range.
Liao Shiqiang; Wang Yuzhu
Shear driven electromagnetic drift-waves in a nonuniform dense magnetoplasma
Linear characteristic properties of high- and low-frequency (in comparison with the cyclotron frequency) electromagnetic drift-waves are studied in a nonuniform, dense magnetoplasma (composed of electrons and ions), in the presence of parallel (magnetic field-aligned) velocity shear, by using quantum magnetohydrodynamic model. By applying the drift-approximation (viz., |{partial_derivative} {sub t}|<<{omega}{sub ci}<<{omega}{sub ce}) to the quantum momentum equations, together with the continuity equations and the Poisson equation, we derive the governing equations for electromagnetic drift-waves with the shear flow. These linear equations are then Fourier transformed to obtain the dispersion relation in both high-frequency and low-frequency regimes. The dispersion relations are then discussed under various limiting cases.
Tariq, Sabeen; Mirza, Arshad M. [Theoretical Plasma Physics Group, Department of Physics, Quaid-i-Azam University, Islamabad 45320 (Pakistan); Masood, Waqas [Theoretical Plasma Physics Division, PINSTECH, P. O. Nilore, Islamabad 44000 (Pakistan); National Center for Physics (NCP), Islamabad 44000 (Pakistan)
Geometric and Electromagnetic Aspects of Fusion Pore Making
For regulated exocytosis, we model the morphology and dynamics of the making of the fusion pore or porosome as a cup-shaped lipoprotein structure (a dimple or pit) on the cytosol side of the plasma membrane. We describe the forming of the dimple by a free boundary problem. We discuss the various forces acting and analyze the magnetic character of the wandering electromagnetic field wave produced by intracellular spatially distributed pulsating (and well observed) release and binding of calcium ions anteceding the bilayer membrane vesicle fusion of exocytosis. Our approach explains the energy efficiency of the observed dimple forming prior to hemifusion and fusion pore, and the observed flickering in secretion. It provides a frame to relate characteristic time length of exocytosis to the frequency, amplitude and direction of propagation of the underlying electromagnetic field wave.
Darya Apushkinskaya; Evgeny Apushkinsky; Bernhelm Booss-Bavnbek; Martin Koch
A method of calculating the response of superconductors to weak electromagnetic fields is formulated. The response is generated from a single- particle Green's function, defined in the presence of an electromagnetic perturbation, that satisfies the conditions imposed by guauge invariance and charge conservation. The response function is thus itself explicitly gauge invariant and charge conserving. The single-particle Green-s function is obtained by making Gorkov's factorizatation of the tiio-partiele Green's funetion in the presence oi the external field. The sy'mmetry' properties of the approximation are used to simplify the calculatioa. This is trivially' carried out in the London limit. An economieal derivation is thus obtaiaed of Anderson's result thai the Bardeen, Cooper, and Sehrieffer quasi particle excitations must be supplemented by collective excitation in order to satisfy the conservation laws. (auth)
Ambegaokar, V.; Kadanoff, L.P.
Phenomenological Model of Current Sheet Canting in Pulsed Electromagnetic Accelerators
Phenomenological Model of Current Sheet Canting in Pulsed Electromagnetic Accelerators T of current sheet canting in pulsed electromagnetic accelerators is the departure of the plasma sheet (that - canting angle [degrees] 5 - plasma frequency [rad/s] 1 Introduction Pulsed electromagnetic accelerators
Choueiri, Edgar
The magnetic field along the jets of NGC 4258 as deduced from high frequency radio observations
We present 2.4" resolution, high sensitivity radio continuum observations of the nearby spiral galaxy NGC 4258 in total intensity and linear polarization obtained with the Very Large Array at 3.6 cm (8.44 GHz). The radio emission along the northern jet and the center of the galaxy is polarized and allows investigation of the magnetic field. Assuming energy-equipartition between the magnetic field and the relativistic particles and distinguishing between (1) a relativistic electron-proton jet and (2) a relativistic electron-positron jet, we obtain average magnetic field strengths of about (1) 310\\muG and (2) 90\\muG. The rotation measure is determined to range from -400 to -800 rad/m^2 in the northern jet. Correcting the observed E-vectors of polarized intensity for Faraday rotation, the magnetic field along the jet turns out to be orientated mainly along the jet axis. An observed tilt with respect to the jet axis may indicate also a toroidal magnetic field component or a slightly helical magnetic field around the northern jet.
M. Krause; A. L"ohr
Nonlinear fan instability of electromagnetic waves
This paper studies the linear and nonlinear stages of the fan instability, considering electromagnetic waves of the whistler frequency range interacting resonantly with energetic electron fluxes in magnetized plasmas. The main attention is paid to determine the wave-particle interaction processes that can lead to the excitation of intense electromagnetic waves by nonequilibrium particle distributions involving suprathermal tails, and to explain under what conditions and through what mechanisms they can occur, develop, and saturate. This paper presents and discusses two main processes: (i) the linear fan instability and (ii) the nonlinear process of dynamical resonance merging, which can significantly amplify the energy carried by linearly destabilized waves after they saturate due to particle trapping. This study consists of (i) determining analytically and numerically, for parameters typical of space and laboratory plasmas, the linear growth rates of whistlers excited by suprathermal particle fluxes through the fan instability, as well as the corresponding thresholds and the physical conditions at which the instability can appear, (ii) building a theoretical self-consistent 3D model and a related numerical code for describing the nonlinear evolution of the wave-particle system, and (iii) performing numerical simulations to reveal and characterize the nonlinear amplification process at work, its conditions of development, and its consequences, notably in terms of electromagnetic wave radiation. The simulations show that when the waves have reached sufficient energy levels owing to the linear fan instability, they saturate by trapping particles and due to the complex dynamics of these particles in the electromagnetic fields, the resonant velocities' domains of the waves overlap and merge, meanwhile a strong increase of the wave energy occurs.
Krafft, C. [Laboratoire de Physique des Plasmas, Ecole Polytechnique, 91128 Palaiseau Cedex (France) and University Paris Sud, 91405 Orsay Cedex (France); Volokitin, A. [Space Research Institute (IKI), 117997, 84/32 Profsoyuznaya Str., Moscow (Russian Federation)
Linear electric field frequency shift (important for next generation electric dipole moment searches) induced in confined gases by a magnetic field gradient
The search for particle electric dipole moments (edm) represents a most promising way to search for physics beyond the standard model. A number of groups are planning a new generation of experiments using stored gases of various kinds. In order to achieve the target sensitivities it will be necessary to deal with the systematic error resulting from the interaction of the well-known $\\overrightarrow{v}\\times \\overrightarrow{E}$ field with magnetic field gradients (often referred to as the geometric phase effect (Commins, ED; Am. J. Phys. \\QTR{bf}{59}, 1077 (1991), Pendlebury, JM \\QTR{em}{et al;} Phys. Rev. \\QTR{bf}{A70}, 032102 (2004)). This interaction produces a frequency shift linear in the electric field, mimicking an edm. In this work we introduce an analytic form for the velocity auto-correlation function which determines the velocity-position correlation function which in turn determines the behavior of the frequency shift (Lamoreaux, SK and Golub, R; Phys. Rev \\QTR{bf}{A71}, 032104 (2005)) and show how it depends on the operating conditions of the experiment. We also discuss some additional issues.
Authors A. L. Barabanov; R. Golub; S. K. Lamoreaux
Poynting-vector based method for determining the bearing and location of electromagnetic sources
A method and apparatus is utilized to determine the bearing and/or location of sources, such as, alternating current (A.C.) generators and loads, power lines, transformers and/or radio-frequency (RF) transmitters, emitting electromagnetic-wave energy for which a Poynting-Vector can be defined. When both a source and field sensors (electric and magnetic) are static, a bearing to the electromagnetic source can be obtained. If a single set of electric (E) and magnetic (B) sensors are in motion, multiple measurements permit location of the source. The method can be extended to networks of sensors allowing determination of the location of both stationary and moving sources.
Simons, David J. (Modesto, CA); Carrigan, Charles R. (Tracy, CA); Harben, Philip E. (Livermore, CA); Kirkendall, Barry A. (Golden, CO); Schultz, Craig A. (Danville, CA)
A Survey of Extremely Low Frequency Magnetic Fields Associated with Electric Vehicles
As electric vehicles progressively increase in number throughout car and truck fleets in the U.S. and abroad, there are likely to be questions raised concerning magnetic field exposure levels within the passenger compartment. The study reported here is an initial effort to establish a measurement methodology and report a set of findings.
Unmanned airborne vehicle (UAV): Flight testing and evaluation of two-channel E-field very low frequency (VLF) instrument
Using VLF frequencies, transmitted by the Navy`s network, for airborne remote sensing of the earth`s electrical, magnetic characteristics was first considered by the United States Geological Survey (USGS) around the mid 1970s. The first VLF system was designed and developed by the USGS for installation and operation on a single engine, fixed wing aircraft used by the Branch of Geophysics for geophysical surveying. The system consisted of five channels. Two E-field channels with sensors consisting of a fixed vertical loaded dipole antenna with pre-amp mounted on top of the fuselage and a gyro stabilized horizontal loaded dipole antenna with pre-amp mounted on a tail boom. The three channel magnetic sensor consisted of three orthogonal coils mounted on the same gyro stabilized platform as the horizontal E-field antenna. The main features of the VLF receiver were: narrow band-width frequency selection using crystal filters, phase shifters for zeroing out system phase variances, phase-lock loops for generating real and quadrature gates, and synchronous detectors for generating real and quadrature outputs. In the mid 1990s the Branch of Geophysics designed and developed a two-channel E-field ground portable VLF system. The system was built using state-of-the-art circuit components and new concepts in circuit architecture. Small size, light weight, low power, durability, and reliability were key considerations in the design of the instrument. The primary purpose of the instrument was for collecting VLF data during ground surveys over small grid areas. Later the system was modified for installation on a Unmanned Airborne Vehicle (UAV). A series of three field trips were made to Easton, Maryland for testing and evaluating the system performance.
Electromagnetic Leptogenesis
We present a new leptogenesis scenario, where the lepton asymmetry is generated by CP violating decays of heavy electroweak singlet neutrinos via electromagnetic dipole moment couplings to the ordinary light neutrinos. Akin to the usual scenario where the decays are mediated through Yukawa interactions, we have shown, by explicit calculations, that the desired asymmetry can be produced through the interference of the corresponding tree-level and one-loop decay amplitudes involving the effective dipole moment operators. We also find that the relationship of the leptogenesis scale to the light neutrino masses is similar to that for the standard Yukawa-mediated mechanism.
Bell, Nicole F; Law, Sandy S C
Nicole F. Bell; Boris J. Kayser; Sandy S. C. Law
Inductance and near fields of a loop antenna in a cold magnetoplasma in the whistler frequency band
The influence of a magnetoplasma on the inductance of a circular loop antenna oriented perpendicular to the ambient static magnetic field and operated in the whistler frequency band is studied. Based on a strict electrodynamic approach, the analytical treatment of the antenna reactance is performed for a uniform rf current distribution along the antenna wire. Calculations are made for plasma parameters and operating frequencies typical for active ionospheric experiments and laboratory rf (helicon) sources of dense magnetized plasmas. It is shown that the plasma influence on the inductance of the loop antenna remains relatively weak, even for antennas with dimensions close to half of the longitudinal whistler wavelength, when the rf field distribution in the antenna near zone is strongly different from that in vacuum. The theoretical predictions are confirmed by measurements performed on the large KROT plasma device. The results obtained are of crucial importance for the preparation of active ionospheric experiments and for the matching of loop antennas used in laboratory rf sources of dense magnetized plasmas.
Gushchin, M. E.; Korobkov, S. V.; Kostrov, A. V. [Institute of Applied Physics, 603950 Nizhny Novgorod (Russian Federation); Zaboronkova, T. M. [Department of Applied Physics, Technical University of Nizhny Novgorod, 603950 Nizhny Novgorod (Russian Federation); Krafft, C. [Laboratoire de Physique des Plasmas, Ecole Polytechnique, 91128 Palaiseau Cedex, Univ. Paris Sud, 91405 Orsay Cedex (France)
Enhanced electro-magnetic energy transfer between a hot and cold body at close spacing due to evanescent fields
Theoretical studies have demonstrated that the energy transfer between a hot and cold body at close spacing (on the order of the radiation wavelength) can greatly exceed the limit for black body radiation (ie, Power = {sigma}T{sup 4}). This effect, due to the coupling of evanescent fields, presents an attractive option for thermo-photovoltaic (TPV) applications (assuming the considerable technical challenges can be overcome). The magnitude of the enhanced energy transfer depends on the optical properties of the hot and cold bodies as characterized by the dielectric functions of the respective materials. The present study considers five different situations as specified by the materials choices for the hot/cold sides: metal/metal, metal/insulator, metal/semiconductor, insulator/insulator, and semiconductor/semiconductor. For each situation, the dielectric functions are specified by typical models. An increase in energy transfer (relative to the black body law) is found for all situations considered, for separations less than one micron, assuming a temperature difference of 1,000 C. The metal/metal situation has the highest increase vs. separation while the semiconductor/semiconductor has the lowest. Factor-of-ten increases are obtained at roughly 0.1 microns for the metal/metal and roughly 0.02 microns for the metal/semiconductor. These studies are helping to increase the understanding of the close-spaced effect in the context of a radiator/TPV context.
Raynolds, J.E. [Lockheed Martin Corp., Schenectady, NY (United States)
Mathematical model of the seismic electromagnetic signals (SEMS) in non crystalline substances
The mathematical model of seismic electromagnetic waves in non crystalline substances is developed and the solutions are discussed to show the possibility of improving the electromagnetic waves especially the electric field. The shear stress of the medium in fourth order tensor gives the equation of motion. Analytic methods are selected for the solutions written in Hansen vector form. From the simulated SEMS, the frequency of seismic waves has significant effects to the SEMS propagating characteristics. EM waves transform into SEMS or energized seismic waves. Traveling distance increases once the frequency of the seismic waves increases from 100% to 1000%. SEMS with greater seismic frequency will give seismic alike waves but greater energy is embedded by EM waves and hence further distance the waves travel.
Dennis, L. C. C.; Yahya, N.; Daud, H.; Shafie, A. [Electromagnetic cluster, Universiti Teknologi Petronas, 31750 Tronoh, Perak (Malaysia)
Plasma Frequency Shift Due to a Slowly Rotating Compact Star
We investigate the effects of a slowly rotating compact gravitational source on electron oscillations in a homogeneous electrically neutral plasma in the absence of an external electric or magnetic field. Neglecting the random thermal motion of the electrons we assume the gravitoelectromagnetic approximation to the general theory of relativity for the gravitational field. It is shown that there is a shift in the plasma frequency and hence in the dielectric constant of the plasma due to the gravitomagnetic force. We also give estimates for the difference in the frequency of radially transmitted electromagnetic signals for typical compact star candidates.
Babur M. Mirza; Hamid Saleem
Measurement and characterization of substation electromagnetic transients. Final report
Little quantitative data exists on radiated electromagnetic interference in substations arising from substation transients. The electromagnetic transient noise produced by normal substation activity such as opening switches and breakers can be significant. Additionally, abnormal events such as faults cause similar electromagnetic noise. The lack of data is in part because suitable measurement equipment techniques have not been generally available to utilities. A new approach to the measurement and characterization of electromagnetic interference caused by substation transients has been developed. A data acquisition system for measurements has been designed and constructed for field use with a bandwidth capability exceeding 100 MHz. Measurements have been taken from staged operations in substations and the resulting data analyzed using specialized computer programs developed for this project. The measurement techniques are presented and the analysis procedures explained in detail. The transients caused by equipment operations in several substations have been studied resulting in an understanding of the expected or typical amplitudes and frequencies of the resulting noise. Suggestions as to equipment tests and withstand levels have been made. An appendix includes raw and analyzed data for research use.
Russell, B.D.
We study the interaction of a high frequency AC current with a magnetic field in an YBCO thin film by using time
an applied magnetic field, and a time varying transport current that does not induce any flux inside the thinWe study the interaction of a high frequency AC current with a magnetic field in an YBCO thin film of flux distributions. We find that the total current distribution can be described as the superposition
Lewis, Robert Michael
Category:Electromagnetic Profiling Techniques | Open Energy Information
source source History View New Pages Recent Changes All Special Pages Semantic Search/Querying Get Involved Help Apps Datasets Community Login | Sign Up Search Category Edit History Facebook icon Twitter icon » Category:Electromagnetic Profiling Techniques Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Geothermalpower.jpg Looking for the Electromagnetic Profiling Techniques page? For detailed information on Electromagnetic Profiling Techniques, click here. Category:Electromagnetic Profiling Techniques Add.png Add a new Electromagnetic Profiling Techniques Technique Pages in category "Electromagnetic Profiling Techniques" This category contains only the following page. F Frequency-Domain Electromagnetic Survey Retrieved from "http://en.openei.org/w/index.php?title=Category:Electromagnetic_Profiling_Techniques&oldid=689835"
Electromagnetic Field Shielding Polyurethane Nanocomposites ...
Abstract Scope, A modified St�ber method is introduced to synthesize Fe@SiO2 nanoparticles (NPs) using ... Colloidal Ag-Pt/TiO2 Nanocomposites for Photocatalysis ... Positron Lifetime Analysis of Polyurea-Nanoclay Composites.
We study electromagnetically induced interference at superconducting qubits. The interaction between qubits and electromagnetic fields can provide additional coupling channels to qubit states, leading to quantum interference in a microwave driven qubit. In particular, the interwell relaxation or Rabi oscillation, resulting respectively from the multi- or single-mode interaction, can induce effective crossovers. The environment is modeled by a multi-mode thermal bath, generating the interwell relaxation. Relaxation induced interference, independent of the tunnel coupling, provides deeper understanding to the interaction between the qubits and their environment. It also supplies a useful tool to characterize the relaxation strength as well as the characteristic frequency of the bath. In addition, we demonstrate the relaxation can generate population inversion in a strongly driving two-level system. On the other hand, different from Rabi oscillation, Rabi oscillation induced interference involves more complicated and modulated photon exchange thus offers an alternative means to manipulate the qubit, with more controllable parameters including the strength and position of the tunnel coupling. It also provides a testing ground for exploring nonlinear quantum phenomena and quantum state manipulation, in not only the flux qubit but also the systems with no crossover structure, e.g. phase qubits.
Lingjie Du; Yang Yu
NVLAP Electromagnetic Compatibility & Telecommunications ...
Electromagnetic Compatibility & Telecommunications LAP. Welcome. This site has been established for new applicants ...
Electromagnetic radiation from lightning return strokes to tall structures.
??The study of the interaction of lightning electromagnetic fields with electrical systems and the design of appropriate protection strategies are generally based on statistical distributions� (more)
Pavanello, Davide
Prediction of magnetic field near power lines by normalized radial basis function network
Over the past several decades, concerns have been raised over the possibility that the exposure to extremely low frequency electromagnetic fields from power lines may have harmful effects on human and living organisms. This work involved the computation ... Keywords: Gradient descent algorithm, Magnetic fields, NRBF network, Power lines, Prediction, Training set
Vesna Rankovi?; Jasna Radulovi?
Analysis Of Factors Affecting Natural Source Slf Electromagnetic
Factors Affecting Natural Source Slf Electromagnetic Factors Affecting Natural Source Slf Electromagnetic Exploration At Geothermal Wells Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: Analysis Of Factors Affecting Natural Source Slf Electromagnetic Exploration At Geothermal Wells Details Activities (0) Areas (0) Regions (0) Abstract: The Super Low Frequency (SLF) electromagnetic exploration was performed by using a nature source SLF electromagnetic detector at two geothermal wells in Peking University. The data of the SLF electromagnetic exploration at well JR-119 and JR-168 were obtained with the observation of continued five days and four times per day at well JR-119 and of one day at well JR-168. Based on these data, the influencing factors of the SI-F electromagnetic exploration were analyzed, which included the relationship
This research explores a new efficient approach for producing electricity from the abundant energy of the sun. A nanoantenna electromagnetic collector (NEC) has been designed, prototyped, and tested. Proof of concept has been validated. The device targets mid-infrared wavelengths where conventional photovoltaic (PV) solar cells do not respond but is abundant in solar energy. The initial concept of designing NEC antennas was based on scaling of radio frequency antenna theory. This approach has proven unsuccessful by many due to not fully understanding and accounting for the optical behavior of materials in the THz region. Also until recent years the nanofabrication methods were not available to fabricate the optical antenna elements. We have addressed and overcome both technology barriers. Several factors were critical in successful implementation of NEC including: 1) frequency-dependent modeling of antenna elements, 2) selection of materials with proper THz properties and 3) novel manufacturing methods that enable economical large-scale manufacturing. The work represents an important step toward the ultimate realization of a low-cost device that will collect as well as convert this radiation into electricity, which will lead to a wide spectrum, high conversion efficiency, and low cost solution to complement conventional PVs.
Steven D. Novack; Dale K. Kotter; Dennis Slafer; Patrick Pinhero
Investigation of electromagnetic welding
We propose several methodologies to study and optimize the electromagnetic process for Electromagnetic Forming (EMF) and Welding (EMW), thereby lowering the necessary process energy up to a factor of three and lengthening ...
Pressl, Daniel G. (Daniel Gerd)
Self-generated magnetic fields in q-distributed plasmas
A quasi-steady magnetic field can be generated with high-frequency electromagnetic radiation through wave-wave and wave-particle interactions in astrophysical plasmas and laser-produced plasmas. Nonlinear coupling equations of self-generated magnetic fields are obtained in nonextensive distribution frame, as a generalization for the standard Maxwellian distribution frame. The numerical results show that self-generated magnetic fields may collapse and lead to various turbulent patterns with different index q.
Li Dingguo [School of Materials Science and Engineering, Nanchang University, Nanchang 330047 (China); School of Nuclear Engineering and Technology, East China Institute of Technology, Fuzhou 344000 (China); Liu Sanqiu [School of Materials Science and Engineering, Nanchang University, Nanchang 330047 (China); School of Science, Nanchang University, Nanchang 330047 (China); Li Xiaoqing [School of Science, Nanchang University, Nanchang 330047 (China)
Deep electromagnetic sounding in central Nevada
Sixteen shallow and deep controlled source electromagnetic soundings were performed in Buena Vista Valley, near Winnemucca, Nevada, to investigate an intra-basement conductor previously detected with magnetotellurics. The survey was carried out with the LBL EM-60 system using a remote magnetic reference for low-frequency geomagnetic noise cancellation, 100-m- and 2.8-km-diameter transmitter loops, and a minicomputer for in-field processing. EM soundings were made at distances from 0.5 to 30 km from three loops over the frequency range 0.02 to 500 Hz. Data were interpreted by means of 1-D inversions and the resulting layered models were pieced together to yield an approximate 2-D geoelectric model along the N-S axis of the valley. The EM soundings and one MT sounding show a 3 to 7 ohm-m zone at a depth of four to seven km. The conductor appears to be deepest at the northern end of the valley and shallowest beneath a basement ridge that seems to divide Buena Vista Valley into two basinal structures. Similar intra-basement conductors are also reported 50 to 75 miles south in the Carson Sink-Fallon areas, suggesting a common source, probably related to an anomalously hot, thin crust.
Wilt, M.; Goldstein, N.E.; Haught, J.R.; Morrison, H.F.
Electromagnetic torque analysis of a DFIG for wind turbines
Electromagnetic torque of doubly fed induction generator (DFIG) is a consequence of the rotor and stator supply. The stator voltage has a fixed amount and frequency. The rotor voltage of the DFIG as a part of a wind turbine has a variable amount and ... Keywords: DFIG, electromagnetic torque, renewable energy, wind turbine
Jurica Smajo; Dinko Vukadinovic
Interaction of biological systems with static and ELF electric and magnetic fields
Although background levels of atmospheric electric and geomagnetic field levels are extremely low, over the past several decades, human beings and other life forms on this planet have been subjected to a dramatically changing electromagnetic milieu. An exponential increase in exposure to electromagnetic fields has occurred, largely because of such technological advances as the growth of electrical power generation and transmission systems, the increased use of wireless communications, and the use of radar. In addition, electromagnetic field generating devices have proliferated in industrial plants, office buildings, homes, public transportation systems, and elsewhere. Although significant increases have occurred in electromagnetic field strenghths spanning all frequency ranges, this symposium addresses only the impact of these fields at static and extremely low frequencies (ELF), primarily 50 and 60 Hz. This volume contains the proceedings of the symposium entitled /open quotes/Interaction of biological systems with static and ELF electric and magnetic fields/close quotes/. The purpose of the symposium was to provide a forum for discussions of all aspects of research on the interaction of static and ELF electromagnetic fields with biological systems. These systems include simple biophysical models, cell and organ preparations, whole animals, and man. Dosimetry, exposure system design, and artifacts in ELF bioeffects research were also addressed, along with current investigations that examine fundamental mechanisms of interactions between the fields and biological processes. Papers are indexed separately.
Anderson, L.E.; Kelman, B.J.; Weigel, R.J. (eds.)
Definition: Time-Domain Electromagnetics | Open Energy Information
Definition Definition Edit with form History Facebook icon Twitter icon » Definition: Time-Domain Electromagnetics Jump to: navigation, search Dictionary.png Time-Domain Electromagnetics Time-domain electromagnetic (TDEM) surveys are active-source soundings which provide information about the electrical structure of the shallow subsurface.[1] View on Wikipedia Wikipedia Definition Transient electromagnetics, (also time-domain electromagnetics / TDEM), is a geophysical exploration technique in which electric and magnetic fields are induced by transient pulses of electric current and the subsequent decay response measured. TEM / TDEM methods are generally able to determine subsurface electrical properties, but are also sensitive to subsurface magnetic properties in applications like UXO detection and
Electro-Optical Sensing Apparatus and Method for Characterizing Free-Space Electromagnetic Radiation
Apparatus and methods for characterizing free-space electromagnetic energy, and in particular, apparatus/method suitable for real-time two-dimensional far-infrared imaging applications are presented. The sensing technique is based on a non-linear coupling between a low-frequency electric field and a laser beam in an electro-optic crystal. In addition to a practical counter-propagating sensing technique, a co-linear approach is described which provides longer radiated field--optical beam interaction length, thereby making imaging applications practical.
Zhang, Xi-Cheng; Libelo, Louis Francis; Wu, Qi
Effects of Electromagnetic Fields on Fish and Invertebrates Task 2.1.3: Effects on Aquatic Organisms Fiscal Year 2012 Progress Report Environmental Effects of Marine and Hydrokinetic Energy
Energy generated by the world�s oceans and rivers offers the potential to make substantial contributions to the domestic and global renewable energy supply. However, the marine and hydrokinetic (MHK) energy industry faces challenges related to siting, permitting, construction, and operation of pilotand commercial-scale facilities. One of the challenges is to understand the potential effects to marine organisms from electromagnetic fields, which are produced as a by-product of transmitting power from offshore to onshore locations through underwater transmission cables. This report documents the progress of the third year of research (fiscal year 2012) to investigate environmental issues associated with marine and hydrokinetic energy (MHK) generation. This work was conducted by Pacific Northwest National Laboratory (PNNL) for the U.S. Department of Energy�s (DOE�s) Office of Energy Efficiency and Renewable Energy (EERE) Wind and Water Technologies Office. The report addresses the effects of electromagnetic fields (EMFs) on selected marine species where significant knowledge gaps exist. The species studied this fiscal year included one fish and two crustacean species: the Atlantic halibut (Hippoglossus hippoglossus), Dungeness crab (Metacarcinus magister), and American lobster (Homarus americanus).
Woodruff, Dana L.; Cullinan, Valerie I.; Copping, Andrea E.; Marshall, Kathryn E.
Electromagnetic Transients in Substations, Volumes 5: Test Data Tapes
EPRI has investigated high-frequency electromagnetic interference (EMI) resulting from high-voltage switching, lightning, and faults in substations. This report provides information about EMI levels to which equipment is exposed.
Velocity damper for electromagnetically levitated materials
A system for damping oscillatory and spinning motions induced in an electromagnetically levitated material is disclosed. Two opposed field magnets are located orthogonally to the existing levitation coils for providing a DC quadrupole field (cusp field) around the material. The material used for generating the DC quadrupole field must be nonconducting to avoid eddy-current heating and of low magnetic permeability to avoid distorting the induction fields providing the levitation. 1 fig.
Fox, R.J.
A system for damping oscillatory and spinning motions induced in an electromagnetically levitated material. Two opposed field magnets are located orthogonally to the existing levitation coils for providing a DC quadrupole field (cusp field) around the material. The material used for generating the DC quadrupole field must be nonconducting to avoid eddy-current heating and of low magnetic permeability to avoid distorting the induction fields providing the levitation.
Extremely high frequency RF effects on electronics.
The objective of this work was to understand the fundamental physics of extremely high frequency RF effects on electronics. To accomplish this objective, we produced models, conducted simulations, and performed measurements to identify the mechanisms of effects as frequency increases into the millimeter-wave regime. Our purpose was to answer the questions, 'What are the tradeoffs between coupling, transmission losses, and device responses as frequency increases?', and, 'How high in frequency do effects on electronic systems continue to occur?' Using full wave electromagnetics codes and a transmission-line/circuit code, we investigated how extremely high-frequency RF propagates on wires and printed circuit board traces. We investigated both field-to-wire coupling and direct illumination of printed circuit boards to determine the significant mechanisms for inducing currents at device terminals. We measured coupling to wires and attenuation along wires for comparison to the simulations, looking at plane-wave coupling as it launches modes onto single and multiconductor structures. We simulated the response of discrete and integrated circuit semiconductor devices to those high-frequency currents and voltages, using SGFramework, the open-source General-purpose Semiconductor Simulator (gss), and Sandia's Charon semiconductor device physics codes. This report documents our findings.
Loubriel, Guillermo Manuel; Vigliano, David; Coleman, Phillip Dale; Williams, Jeffery Thomas; Wouters, Gregg A.; Bacon, Larry Donald; Mar, Alan
A Simple Method for Generating Electromagnetic Oscillations
We propose a novel approach to the generation of electromagnetic oscillations by means of a low-frequency pumping of two coupled linear oscillators. A theory of such generation mechanism is proposed, and its feasibility is demonstrated by using coupled RLC oscillators. A comparison of the theoretical results and the experimental data is presented.
Vyacheslav Buts; Dmitriy Vavriv; Oleg Nechayev; Dmitriy Tarasov
The crosswell electromagnetic response of layered media
Crosswell electromagnetic measurements are a promising new geophysical technique for mapping subsurface electrical conductivity which can provide information about the subsurface distribution of water, oil or steam. In this work the fields from a low frequency vertical magnetic dipole have been examined from the specific point of view of their application to the determination of the conductivity of a layered medium. The source and the receiver were placed inside two separate boreholes. The range of penetration of such a crosswell system for typical earth resistivities and for currently available transmitter and receiver technologies was found to be up to 1,000 meters so problems in ground water and petroleum reservoir characteristics can be practically examined. An analysis of the behavior of the magnetic fields at the boundary between two half-spaces showed that the horizontal magnetic field component, H{rho}, and the vertical derivative of a vertical component, {delta}H{sub z}/{delta}z, are more sensitive to conductivity variations than H{sub z}. The analysis of derivatives led to the concept of measuring the conductivity directly using a second vertical derivative of H{sub z}. Conductivity profiles interpreted from field data using this technique reproduced accurately the electrical logs for a test site near Devine, Texas. It was found in this study that the inversion techniques are more stable when the first vertical derivative of H{sub z} is used rather than H{sub z} itself. Using data from a salt water injection experiment at the Richmond Field test site in Berkeley it was also found that these robust layer inversions were successful in identifying the preferential flow direction of the injected brine to four boreholes surrounding the injection well.
Deszcz-Pan, M. [Univ. of California, Berkeley, CA (United States). Dept. of Materials Science and Mineral Engineering]|[Lawrence Berkeley Lab., CA (United States). Earth Sciences Div.
Perpendicular propagating electromagnetic envelope solitons in electron-positron-ion plasma
The nonlinear amplitude modulation of electromagnetic waves propagating perpendicular to the direction of ambient magnetic field in a uniform collisionless magnetized electron-positron-ion plasma is studied. The Krylov-Bogoliubov-Mitropolsky perturbation method is employed to derive nonlinear Schroedinger equation, which describes the amplitude dynamics of perturbed magnetic field. The modulation instability criterion reveals that the low frequency mode is always stable, whereas the high frequency mode becomes modulationally unstable for certain ranges of wave number and positron-to-electron density ratio. Furthermore, the positron-to-electron density ratio as well as the strength of ambient magnetic field is found to have significant effect on the solitary wave solutions of the nonlinear Schroedinger equation, namely, dark and bright envelope solitons.
Jehan, Nusrat [Department of Physics, Theoretical Plasma Physics Group, Quaid-i-Azam University, Islamabad 45320 (Pakistan); Pakistan Atomic Energy Commission, P.O. Box 1114, Islamabad 44000 (Pakistan); Salahuddin, M. [Pakistan Atomic Energy Commission, P.O. Box 1114, Islamabad 44000 (Pakistan); Mirza, Arshad M. [Department of Physics, Theoretical Plasma Physics Group, Quaid-i-Azam University, Islamabad 45320 (Pakistan)
Detailed discussion of a linear electric field frequency shift (important for next generation) electric dipole moment searches) induced in confined gases by a magnetic field gradient: Implications for electric dipole moment experiments (II)
The search for particle electric dipole moments represents a most promising way to search for physics beyond the standard model. A number of groups are planning a new generation of experiments using stored gases of various kinds. In order to achieve the target sensitivities it will be necessary to deal with the systematic error resulting from the interaction of the well-known E x v field with magnetic field gradients (often referred to as the geometric phase effect [9,10]). This interaction produces a frequency shift linear in the electric field, mimicking an edm. In this work we introduce an analytic model for the correlation function which determines the behavior of the frequency shift [11], and show in detail how it depends on the operating conditions of the experiment. We also propose a method to directly measure ths correlation function under the exact conditions of a given experiment.
A. L. Barabanov; R. Golub; S. K. Lamoreaux
Long-time solution of the time-dependent Schroedinger equation for an atom in an electromagnetic field using complex coordinate contours
We demonstrate that exterior complex scaling (ECS) can be used to impose outgoing wave boundary conditions exactly on solutions of the time-dependent Schrodinger equation for atoms in intense electromagnetic pulses using finite grid methods. The procedure is formally exact when applied in the appropriate gauge and is demonstrated in a calculation of high harmonic generation in which multiphoton resonances are seen for long pulse durations. However, we also demonstrate that while the application of ECS in this way is formally exact, numerical error can appear for long time propagations that can only be controlled by extending the finite grid. A mathematical analysis of the origins of that numerical error, illustrated with an analytically solvable model, is also given.
Tao, Liang; Vanroose, Wim; Reps, Brian; Rescigno, Thomas N.; McCurdy, C. William
Algorithms for irreducible infeasible subset detection in CSP - Application to frequency planning and graph k-coloring.
??The frequency assignment (FAP) consists in assigning the frequency on the radio links of a network which satisfiesthe electromagnetic interference among the links. Given the� (more)
Hu, Jun
High-frequency absorption of the dynamic mixed state in the surface superconductivity region
We analyze the absorption of a high-frequency electromagnetic field in the type II superconductor Pb{sub 0.8}In{sub 0.2} in magnetic fields H{sub c2} < H < H{sub c3}. The absorption component proportional to the rate of variation of the external magnetic field is detected. We assume that this absorption component is associated with the dynamic mixed state of the superconducting shell containing 2D magnetic flux vortices (Kulik vortices). The motion of these vortices under the action of the critical current ensures the required difference between the external and internal magnetic inductions of the superconducting shell upon a change in the external magnetic field. This model correctly describes the observed behavior of absorption of rf electromagnetic radiation.
Berezin, V. A., E-mail: firstname.lastname@example.com; Tulin, V. A., E-mail: firstname.lastname@example.com [Russian Academy of Sciences, Institute of Microelectronics Technology and High-Purity Materials (Russian Federation)
Tunability enhanced electromagnetic wiggler
The invention discloses a wiggler used in synchrotron radiation sources and free electron lasers, where each pole is surrounded by at least two electromagnetic coils. The electromagnetic coils are energized with different amounts of current to provide a wide tunable range of the on-axis magnetic flux density, while preventing magnetic saturation of the poles. 14 figs.
Schlueter, R.D.; Deis, G.A.
Material Shielding of Power Frequency Magnetic Fields: Research and Testing Results from the EPRI Power Delivery Center -- Lenox
Magnetic fields from power lines and other electrical facilities can interfere with sensitive electronic equipment such as computers, electron microscopes, medical diagnostic and monitoring equipment, and air traffic control displays. Shields can be designed to reduce the magnetic field strength in the areas of interest, but attention must be given to certain aspects of shield design. This report deals with three aspects of practical shield construction: flat sheet dimensions, joining sheets, and thin co...
Detailed Discussion of a linear electric field frequency shift induced in confined gases by a magnetic field gradient: Implications for neutron electric dipole moment experiments
The search for particle electric dipole moments (edm) is one of the best places to look for physics beyond the standard model because the size of time reversal violation predicted by the standard model is incompatible with present ideas concerning the creation of the Baryon-Antibaryon asymmetry. As the sensitivity of these edm searches increases more subtle systematic effects become important. We develop a general analytical approach to describe a systematic effect recently observed in an electric dipole moment experiment using stored particles \\cite{JMP}. Our approach is based on the relationship between the systematic frequency shift and the velocity autocorrelation function of the resonating particles. Our results, when applied to well-known limiting forms of the correlation function, are in good agreement with both the limiting cases studied in recent work that employed a numerical/heuristic analysis. Our general approach explains some of the surprising results observed in that work and displays the rich behavior of the shift for intermediate frequencies, which has not been previously studied.
S. K. Lamoreaux; R. Golub
Electro-optical and Magneto-optical Sensing Apparatus and Method for Characterizing Free-space Electromagnetic Radiation
Apparatus and methods for characterizing free-space electromagnetic energy, and in particular, apparatus/method suitable for real-time two-dimensional far-infrared imaging applications are presented. The sensing technique is based on a non-linear coupling between a low-frequency electric (or magnetic) field and a laser beam in an electro-optic (or magnetic-optic) crystal. In addition to a practical counter-propagating sensing technique, a co-linear approach is described which provides longer radiated field-optical beam interaction length, thereby making imaging applications practical.
Zhang, Xi-Cheng; Riordan, Jenifer Ann; Sun, Feng-Guo
Property:FieldProcedures | Open Energy Information
FieldProcedures FieldProcedures Jump to: navigation, search Property Name FieldProcedures Property Type Text Description Description of actions, equipment and footprint of the exploration activity Subproperties This property has the following 39 subproperties: A Active Seismic Techniques Airborne Gravity Survey Audio-Magnetotellurics C Controlled Source Audio MT Cross-Dipole Acoustic Log D DC Resistivity Survey (Dipole-Dipole Array) DC Resistivity Survey (Mise-Á-La-Masse) DC Resistivity Survey (Pole-Dipole Array) DC Resistivity Survey (Schlumberger Array) DC Resistivity Survey (Wenner Array) Development Drilling Direct-Current Resistivity Survey Drilling Techniques E Earth Tidal Analysis Electrical Profiling Configurations Electromagnetic Techniques Exploration Drilling F FMI Log Frequency-Domain Electromagnetic Survey
Sensory information in local field potentials and spikes from visual and auditory cortices: time scales and frequency bands
Studies analyzing sensory cortical processing or trying to decode brain activity often rely on a combination of different electrophysiological signals, such as local field potentials (LFPs) and spiking activity. Understanding the relation between these ... Keywords: Audition, Firing rates, Information theory, Oscillations, Population coding, Vision
Andrei Belitski; Stefano Panzeri; Cesare Magri; Nikos K. Logothetis; Christoph Kayser
Nonlinear generation mechanism for the vortical electric field in magnetized plasma media
A physical mechanism and nonlinear mathematical formalism for study of generation and further amplification of the vortical electric field in the magnetized plasma are proposed. A modulation instability process in a plasma medium is considered in a strong constant magnetic field. The plasmon condensate is modulated not by a low-frequency ionic sound as is usually done, but by the beating of two high-frequency transverse electromagnetic waves propagating along the external magnetic field. Conditions in which aperiodic instability occurs are found and its increment is defined. This instability leads to a decrease in the scale of Langmuir turbulence along the external magnetic field and to the generation of electromagnetic fields. Dissipative property of the medium increases an amplitude threshold of the pumping waves. It is shown that for sufficiently large amplitudes of pumping waves the effect described in the paper is the defining nonlinear process.
Aburjania, G. D. [Tbilisi State University, M. Nodia Institute of Geophysics, Tbilisi 0143 (Georgia)
Cerenkov radio pulses from electromagnetic showers in the time domain
The electric field of the Cerenkov radio pulse produced by a single charged particle track in a dielectric medium is derived from first principles. An algorithm is developed to obtain the pulse in the time domain for numerical calculations. The algorithm is implemented in a Monte Carlo simulation of electromagnetic showers in dense media (specifically designed for coherent radio emission applications) as might be induced by interactions of ultrahigh energy neutrinos. The coherent Cerenkov radio emission produced by such showers is obtained simultaneously both in the time and frequency domains. A consistency check performed by Fourier transforming the pulse in time and comparing it to the frequency spectrum obtained directly in the simulations yields, as expected, fully consistent results. The reversal of the time structure inside the Cerenkov cone and the signs of the corresponding pulses are addressed in detail. The results, besides testing algorithms used for reference calculations in the frequency domain, shed new light into the properties of the radio pulse in the time domain. The shape of the pulse in the time domain is directly related to the depth development of the excess charge in the shower and its width to the observation angle with respect to the Cerenkov direction. This information can be of great practical importance for interpreting actual data.
Alvarez-Muniz, Jaime; Romero-Wolf, Andres; Zas, Enrique [Depto. de Fisica de Particulas and Instituto Galego de Fisica de Altas Enerxias, Universidade de Santiago de Compostela, 15782 Santiago de Compostela (Spain); Department of Physics and Astronomy, University of Hawaii at Manoa, Honolulu, Hawaii 96822 (United States); Depto. de Fisica de Particulas and Instituto Galego de Fisica de Altas Enerxias, Universidad de Santiago de Compostela, 15782 Santiago de Compostela (Spain)
Microslots : scalable electromagnetic instrumentation
This thesis explores spin manipulation, fabrication techniques and boundary conditions of electromagnetism to bridge the macroscopic and microscopic worlds of biology, chemistry and electronics. This work is centered around ...
Maguire, Yael G., 1975-
Nonlinear Landau damping of transverse electromagnetic waves in dusty plasmas
High-frequency transverse electromagnetic waves in a collisionless isotropic dusty plasma damp via nonlinear Landau damping. Taking into account the latter we have obtained a generalized set of Zakharov equations with local and nonlocal terms. Then from this coupled set of Zakharov equations a kinetic nonlinear Schroedinger equation with local and nonlocal nonlinearities is derived for special cases. It is shown that the modulation of the amplitude of the electromagnetic waves leads to the modulation instability through the nonlinear Landau damping term. The maximum growth rate is obtained for the special case when the group velocity of electromagnetic waves is close to the dust acoustic velocity.
Tsintsadze, N. L. [E. Andronikashvili Institute of Physics, Tbilisi 0171 (Georgia); Department of Physics, Government College University, Lahore 54000 (Pakistan); Salam Chair in Physics, Government College University, Lahore 54000 (Pakistan); Chaudhary, Rozina [Department of Physics, Government College University, Lahore 54000 (Pakistan); Salam Chair in Physics, Government College University, Lahore 54000 (Pakistan); Shah, H. A. [Department of Physics, Government College University, Lahore 54000 (Pakistan); Murtaza, G. [Salam Chair in Physics, Government College University, Lahore 54000 (Pakistan)
Gradient instabilities of electromagnetic waves in Hall thruster plasma
This paper presents a linear analysis of gradient plasma instabilities in Hall thrusters. The study obtains and analyzes the dispersion equation of high-frequency electromagnetic waves based on the two-fluid model of a cold plasma. The regions of parameters corresponding to unstable high frequency modes are determined and the dependence of the increments and intrinsic frequencies on plasma parameters is obtained. The obtained results agree with those of previously published studies.
Tomilin, Dmitry [Department of Electrophysics, Keldysh Research Centre, Moscow 125438 (Russian Federation)
Enhanced Interpretation of Electromagnetic Signature Analysis for Large Machines
This project developed and applied frequency domain models to enhance interpretation of electromagnetic signature analysis (EMSA) for large electrical generators. The project's rationale was to provide a prediction of the native frequency response of the winding calculated from machine dimensions and design data so that the positions of the resonances would be known a priore. This procedure allowed augmentation of an EMSA spectrum at the characteristic resonant frequencies of the machine in the interpret...
Active molecular plasma in a magnetic field
The propagation of electromagnetic oscillations in an active molecules plasma in a constant external magnetic field is investigated. (AIP)
Kovtun, V.P.
Effects of Electromagnetic Fields on Fish and Invertebrates: Task 2.1.3: Effects on Aquatic Organisms - Fiscal Year 2011 Progress Report - Environmental Effects of Marine and Hydrokinetic Energy
This fiscal year (FY) 2011 progress report (Task 2.1.3 Effects on Aquatic Organisms, Subtask 22.214.171.124 Electromagnetic Fields) describes studies conducted by PNNL as part of the DOE Wind and Water Power Program to examine the potential effects of electromagnetic fields (EMF) from marine and hydrokinetic devices on aquatic organisms, including freshwater and marine fish and marine invertebrates. In this report, we provide a description of the methods and results of experiments conducted in FY 2010-FY 2011 to evaluate potential responses of selected aquatic organisms. Preliminary EMF laboratory experiments during FY 2010 and 2011 entailed exposures with representative fish and invertebrate species including juvenile coho salmon (Oncorhynchus kisutch), Atlantic halibut (Hippoglossus hippoglossus), California halibut (Paralicthys californicus), rainbow trout (Oncorhynchus mykiss), and Dungeness crab (Metacarcinus magister). These species were selected for their ecological, commercial, and/or recreational importance, as well as their potential to encounter an MHK device or transmission cable during part or all of their life cycle. Based on previous studies, acute effects such as mortality were not expected to occur from EMF exposures. Therefore, our measurement endpoints focused on behavioral responses (e.g., detection of EMF, interference with feeding behavior, avoidance or attraction to EMF), developmental changes (i.e., growth and survival from egg or larval stage to juvenile), and exposure markers indicative of physiological responses to stress. EMF intensities during the various tests ranged from 0.1 to 3 millitesla, representing a range of upper bounding conditions reported in the literature. Experiments to date have shown there is little evidence to indicate distinct or extreme behavioral responses in the presence of elevated EMF for the species tested. Several developmental and physiological responses were observed in the fish exposures, although most were not statistically significant. Additional species are currently planned for laboratory testing in the next fiscal year (e.g. an elasmobranch, American lobster) to provide a broader assessment of species important to stakeholders. The collective responses of all species will be assessed in terms of life stage, exposure scenarios, and biological relevance, to address current uncertainties related to effects of EMF on aquatic organisms.
Woodruff, Dana L.; Schultz, Irvin R.; Marshall, Kathryn E.; Ward, Jeffrey A.; Cullinan, Valerie I.
Electromagnetic SCRF Cavity Tuner
A novel prototype of SCRF cavity tuner is being designed and tested at Fermilab. This is a superconducting C-type iron dominated magnet having a 10 mm gap, axial symmetry, and a 1 Tesla field. Inside the gap is mounted a superconducting coil capable of moving {+-} 1 mm and producing a longitudinal force up to {+-} 1.5 kN. The static force applied to the RF cavity flanges provides a long-term cavity geometry tuning to a nominal frequency. The same coil powered by fast AC current pulse delivers mechanical perturbation for fast cavity tuning. This fast mechanical perturbation could be used to compensate a dynamic RF cavity detuning caused by cavity Lorentz forces and microphonics. A special configuration of magnet system was designed and tested.
Kashikhin, V.; Borissov, E.; Foster, G.W.; Makulski, A.; Pischalnikov, Y.; Khabiboulline, T.; /Fermilab
Amplitude and frequency experimental field measurements of a rotating?imbalance seismic source associated with changes in lithology surrounding a borehole
Field measurements of the vibration amplitude of a rotating?imbalance seismic source in a liquid?filled borehole are described. The borehole was a cased oil well that had been characterized by gamma?ray cement bond and compensated neutron litho?density/gamma?ray logs. The well logs indicated an abrupt transition from shale to limestone at a depth of 2638 ft. The vibration amplitude and frequency of a rotating?imbalance seismic source was measured versus applied voltage as the source was raised from 2654 to 2618 ft through the shale�limestone transition. It was observed that the vibration amplitude changed by approximately 10% in magnitude and the frequency changed approximately 15% as the source passed the shale�limestone transition. The measurements were compared to predictions provided by a two?dimensional analytical model of a rotating?imbalance source located in a liquid?filled bore hole. It was observed that the sensitivity of the experimentally measured vibration amplitude of the seismic source to the properties of the surrounding geologic media was an order of magnitude greater than that predicted by the two?dimensional analytical model.
Fluidic electrodynamics: Approach to electromagnetic propulsion
We report on a new methodological approach to electrodynamics based on a fluidic viewpoint. We develop a systematic approach establishing analogies between physical magnitudes and isomorphism (structure-preserving mappings) between systems of equations. This methodological approach allows us to give a general expression for the hydromotive force, thus re-obtaining the Navier-Stokes equation departing from the appropriate electromotive force. From this ground we offer a fluidic approach to different kinds of issues with interest in propulsion, e.g., the force exerted by a charged particle on a body carrying current; the magnetic force between two parallel currents; the Magnus's force. It is shown how the intermingle between the fluid vector fields and electromagnetic fields leads to new insights on their dynamics. The new concepts introduced in this work suggest possible applications to electromagnetic (EM) propulsion devices and the mastery of the principles of producing electric fields of required configuration in plasma medium.
Martins, Alexandre A.; Pinheiro, Mario J. [Institute for Plasmas and Nuclear Fusion and Instituto Superior Tecnico Lisboa, Portugal 3220.127.116.111.92.43 (Portugal); Department of Physics and Institute for Plasmas and Nuclear Fusion and Instituto Superior Tecnico Lisboa, Portugal 3220.127.116.111.93.22 (Portugal)
Electromagnetic soundings for geothermal resources in Dixie Valley, Nevada
An electromagnetic (EM) sounding survey was performed over a region encompassing the Dixie Valley geothermal field to map the subsurface resistivity in the geothermal field and the surrounding area. The EM survey, consisting of 19 frequency-domain depth soundings made with the LBL EM-60 system, was undertaken to explore a narrow region adjacent to the Stillwater Range to a depth of 2 to 3 km. Lithologic and well log resistivity information from well 66-21 show that for EM interpretation the section can be reduced to a three-layer model consisting of moderately resistive alluvial sediments, low resistivity lacustrine sediments, and high resistivity Tertiary volcanics and older rocks. This three layer model was used as a starting point in interpreting EM sounding data. Variations in resistivity and thickness provided structural information and clues to the accumulation of geothermal fluids. The interpreted soundings reveal a 1 to 1.5-km-deep low-resistivity zone spatially associated with the geothermal field. The shallow depth suggests that the zone detected is either fluid leakage or hydrothermal alteration, rather than high-temperature reservoir fluids. The position of the low-resistivity zone also conforms to changes in depth to the high resistivity basal layer, suggesting that faulting is a control on the location of productive intervals. 10 refs., 7 figs.
Wilt, M.J.; Goldstein, N.E.
Influence of lateral target size on hot electron production and electromagnetic pulse emission from laser-irradiated metallic targets
The influences of lateral target size on hot electron production and electromagnetic pulse emission from laser interaction with metallic targets have been investigated. Particle-in-cell simulations at high laser intensities show that the yield of hot electrons tends to increase with lateral target size, because the larger surface area reduces the electrostatic field on the target, owing to its expansion along the target surface. At lower laser intensities and longer time scales, experimental data characterizing electromagnetic pulse emission as a function of lateral target size also show target-size effects. Charge separation and a larger target tending to have a lower target potential have both been observed. The increase in radiation strength and downshift in radiation frequency with increasing lateral target size can be interpreted using a simple model of the electrical capacity of the target.
Chen Ziyu; Li Jianfeng; Yu Yong; Li Xiaoya; Peng Qixian; Zhu Wenjun [National Key Laboratory of Shock Wave and Detonation Physics, Institute of Fluid Physics, China Academy of Engineering Physics, Mianyang, Sichuan 621900 (China); Wang Jiaxiang [State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200062 (China)
Electromagnetic energy within magnetic spheres
Consider that an incident plane wave is scattered by a homogeneous and isotropic magnetic sphere of finite radius. We determine, by means of the rigorous Mie theory, an exact expression for the time-averaged electromagnetic energy within this particle. For magnetic scatterers, we find that the value of the average internal energy in the resonance picks is much larger than the one associated with a scatterer with the same nonmagnetic medium properties. This result is valid even, and specially, for low size parameter values. Expressions for the contributions of the radial and angular field components to the internal energy are determined. For the analytical study of the weak absorption regime, we derive an exact expression for the absorption cross section in terms of the magnetic Mie internal coefficients. We stress that although the electromagnetic scattering by particles is a well-documented topic, almost no attention has been devoted to magnetic scatterers. Our aim is to provide some new analytical results, which can be used for magnetic particles, and empha- size the unusual properties of the magnetic scatters, which could be important in some applications.
Tiago Jose Arruda; Alexandre Souto Martinez
Graphene Frequency Multipliers
In this letter, the ambipolar transport properties of graphene flakes have been used to fabricate full-wave signal rectifiers and frequency-doubling devices. By correctly biasing an ambipolar graphene field-effect transistor ...
Wang, Han
Electromagnetic radiation detector
An electromagnetic radiation detector including a collimating window, a cathode member having a photoelectric emissive material surface angularly disposed to said window whereby radiation is impinged thereon at acute angles, an anode, separated from the cathode member by an evacuated space, for collecting photoelectrons emitted from the emissive cathode surface, and a negatively biased, high transmissive grid disposed between the cathode member and anode.
Benson, Jay L. (Albuquerque, NM); Hansen, Gordon J. (Albuquerque, NM)
Cone structure and focusing of VLF and LF electromagnetic waves at high altitudes in the ionosphere
The frequency and angle dependencies of the electric field radiated by an electric dipole E = E[sub 0] cos [omega]t are studied through numerical calculations of [vert bar]E[vert bar] in the VLF and LF frequency bands 0.02f[sub b] [le] F [le] 0.5f[sub b] in a model ionosphere over an altitude region of 800-6000 km where the wave frequency and electron gyrofrequency varies between F [approximately]4 - 500 kHz and f[sub b] [approx equal] (1.1 to 0.2) MHz respectively. It is found that the amplitudes of the electric field have large maxima in four regions: close to the direction of the Earth magnetic field line B[sub 0] (it is called the axis field E[sub 0]), in the Storey E[sub St], reversed Storey E[sub RevSt], and resonance E[sub Res] cones. The maximal values of E[sub 0], E[sub Res], and E[sub RevSt] are the most pronounced close to the lower hybrid frequency, F [approximately] F[sub L]. The flux of the electric field is concentrated in very narrow regions, with the apex angles of the cones [delta][beta] [approx equal] (0.1-1) deg. The enhancement and focusing of the electric field increases with altitude starting at Z>800 km. At Z [ge] 1000 up to 6000 km, the relative value of [vert bar]E[vert bar], in comparison with its value at Z = 800 km is about (10[sup 2] to 10[sup 4]) times larger. Thus, the flux of VLF and LF electromagnetic waves generated at high altitudes in the Earth's ionosphere are trapped into very narrow conical beams similar to laser beams. 7 refs., 14 figs., 5 tabs.
Alpert, Ya.L. (Harvard Smithsonian Center for Astrophysics, Cambridge, MA (United States)); Green, J.L. (NASA/Goddard Space Flight Center, Greenbelt, MD (United States))
Concerning Measurement of Gravitomagnetism in Electromagnetic Systems
Measurement of gravitomagnetic field is of fundamental importance as a test of general relativity. Here we present a new theoretical project for performing such a measurement based on detection of the electric field arising from the interplay between the gravitomagnetic and magnetic fields in the stationary axial-symmetric gravitational field of a slowly rotating massive body. Finally it is shown that precise magnetometers based on superconducting quantum interferometers could not be designed for measurement of the gravitomagnetically induced magnetic field in the cavity of a charged capacitor since they measure the circulation of a vector potential of electromagnetic field, i.e., an invariant quantity including the sum of electric and magnetic fields, and the general-relativistic magnetic part will be totally cancelled by the electric one which is in good agreement with the experimental results.
B. J. Ahmedov; N. I. Rakhmatov
Plasma heating by an rf electric field
In an analysis of the excitation of plasma waves by an electromagnetic wave at a frequency near the plasma frequency, the decay instabilities of first and second orders are taken into account. (AIP)
Musher, S.L.; Rubenchik, A.M.
Electromagnetic interferences from plasmas generated in meteoroids impacts
Submitted to Europhysics Letters. It is shown that the plasma, generated during an impact of a meteoroid with an artificial satellite, can produce electromagnetic radiations below the microwave frequency range. These interferences can disturb the regular satellite operations. Pacs 96.50.Kr: Meteors and meteoroids. Pacs 52.50.Lp: Plasma production and heating by shock waves and compression.
Luigi Foschini
It is shown that the plasma, generated during an impact of a meteoroid with an artificial satellite, can produce electromagnetic radiation below the microwave frequency range. This interference is shown to exceed local noise sources and might disturb regular satellite operations.
Boundary effects of electromagnetic vacuum fluctuations on charged particles
The effects of electromagnetic vacuum fluctuations with the boundary on charged particles is investigated. They may be observed via an electron interference experiment near the conducting plate, where boundary effects of vacuum fluctuations are found significant on coherence reduction of the electrons. The dynamics of the charge under the influence of quantized electromagnetic fields with a conducting plate is also studied. The corresponding stochastic equation of motion is derived in the semiclassical approximation, and the behavior of the charge's velocity fluctuations is discussed.
Tai-Hung Wu; Jen-Tsung Hsiang; Da-Shin Lee
Wu, Tai-Hung; Lee, Da-Shin
Potential field and electromagnetic studies: Introduction
Several aeromagnetic surveys have been flown over Long Valley at different altitudes and line spacings. The one most often referred to was a high level (4 km or 13,200 feet above sea level barometric survey) flown by the USGS in 1973 along E-W lines spaced 1.7 km apart. Investigators attempted a quantitative interpretation of the data, and suggested that extensive post-caldera hydrothermal activity may have drastically altered the composition of the titanomagnetites in the Bishop Tuff, causing the magnetic low in the area of the resurgent dome. Others have reported in informal conversations, as is now supported by holes M-1 and 44-016, that the low in the western part of the caldera is the result of lower magnetization of the post-caldera volcanics and a large wedge of Paleozoic metasediments that floor the caldera. The true nature of the magnetic high on the eastern flank of the resurgent dome has been revealed by recent paleomagnetic work and from a detailed aeromagnetic survey flown 400 feet above terrain for the USGS in 1979. 6 refs., 2 figs.
Goldstein, N.E.
The sensitivity of children to electromagnetic fields
atomic bomb during puberty, al- though the risk also increased in women who were ?10 years old (an age
Kheifets, Leeka; Repacholi, M; Saunders, R; van Deventer, E
Banded electromagnetic stator core
A stator core for an electromagnetic pump includes a plurality of circumferentially adjoining groups of flat laminations disposed about a common centerline axis and collectively defining a central bore and a discontinuous outer perimeter, with adjacent groups diverging radially outwardly to form V-shaped gaps. An annular band surrounds the groups and is predeterminedly tensioned to clamp together the laminations, and has a predetermined flexibility in a radial direction to form substantially straight bridge sections between the adjacent groups. 5 figures.
Fanning, A.W.; Gonzales, A.A.; Patel, M.R.; Olich, E.E.
Is it possible to create a quantum electromagnetic "black hole" at the Large Hadron Collider?
As demonstrated by Chernodub, strong magnetic field forces vacuum to develop real condensates of electrically charged rho mesons, which form an anisotropic inhomogeneous superconducting state similar to Abrikosov vortex lattice. As far as electromagnetic field behaviour is concerned, this state of vacuum constitutes a hyperbolic metamaterial [1]. Here we demonstrate that spatial variations of magnetic field may lead to formation of electromagnetic "black holes" inside this metamaterial. Similar to real black holes, horizon area of the electromagnetic "black holes" is quantized in units of the effective "Planck scale" squared. The magnetic fields of the required strength and geometrical configuration may be created on Earth in heavy-ion collisions at the Large Hadron Collider. We evaluate electromagnetic field distribution around an electromagnetic "black hole" which may be created as a result of such collision.
Igor I. Smolyaninov
Electromagnetic Compatibility in Nuclear Power Plants
Electromagnetic compatibility (EMC) has long been a key element of qualification for mission critical instrumentation and control (I&C) systems used by the U.S. military. The potential for disruption of safety-related I&C systems by electromagnetic interference (EMI), radio-frequency interference (RFI), or power surges is also an issue of concern for the nuclear industry. Experimental investigations of the potential vulnerability of advanced safety systems to EMI/RFI, coupled with studies of reported events at nuclear power plants (NPPs) that are attributed to EMI/RFI, confirm the safety significance of EMC for both analog and digital technology. As a result, Oak Ridge National Laboratory has been engaged in the development of the technical basis for guidance that addresses EMC for safety-related I&C systems in NPPs. This research has involved the identification of engineering practices to minimize the potential impact of EMI/RFI and power surges and an evaluation of the ambient electromagnetic environment at NPPs to tailor those practices for use by the nuclear industry. Recommendations for EMC guidance have been derived from these research findings and are summarized in this paper.
Ewing, P.D.; Kercel, S.W.; Korsah, K.; Wood, R.T.
A characterization of the electromagnetic stress-energy tensor
In a previous paper, we pointed out how a dimensional analysis of the stress-energy tensor of the gravitational field allows to derive the field equation of General Relativity. In this note, we comment an analogous reasoning in presence of a 2-form, that allows to characterize the so called electromagnetic stress-energy tensor.
J. Navarro; J. B. Sancho
Electromagnetic Transients Program (EMTP) Workbook
High-speed electromagnetic transients are often the controlling factor in transmission system design and operation. This workbook provides case studies for introducing the basics of electromagnetic transient analysis. Sample problems demonstrate analyses of such transients with the EMTP computer code.BackgroundThe electromagnetic transients program (EMTP) is a versatile and efficient computer program that utilities worldwide use for analyzing high-speed power ...
Physics Out Loud - Electromagnetic Force
Detector Previous Video (Detector) Physics Out Loud Main Index Next Video (Electron Scattering) Electron Scattering Electromagnetic Force Cynthia Keppel, a nuclear physicist,...
Microfabricated ion frequency standard
A microfabricated ion frequency standard (i.e. an ion clock) is disclosed with a permanently-sealed vacuum package containing a source of ytterbium (Yb) ions and an octupole ion trap. The source of Yb ions is a micro-hotplate which generates Yb atoms which are then ionized by a ultraviolet light-emitting diode or a field-emission electron source. The octupole ion trap, which confines the Yb ions, is formed from suspended electrodes on a number of stacked-up substrates. A microwave source excites a ground-state transition frequency of the Yb ions, with a frequency-doubled vertical-external-cavity laser (VECSEL) then exciting the Yb ions up to an excited state to produce fluorescent light which is used to tune the microwave source to the ground-state transition frequency, with the microwave source providing a precise frequency output for the ion clock.
Schwindt, Peter (Albuquerque, NM); Biedermann, Grant (Albuquerque, NM); Blain, Matthew G. (Albuquerque, NM); Stick, Daniel L. (Albuquerque, NM); Serkland, Darwin K. (Albuquerque, NM); Olsson, III, Roy H. (Albuquerque, NM)
Coherent spin control by electromagnetic vacuum fluctuations
In coherent control, electromagnetic vacuum fluctuations usually cause coherence loss through irreversible spontaneous emission. However, since the dissipation via emission is essentially due to correlation of the fluctuations, when emission ends in a superposition of multiple final states, correlation between different pathways may build up if the 'which way' information is not fully resolved (i.e., the emission spectrum is broader than the transition energy range). Such correlation can be exploited for spin-flip control in a {Lambda}-type three-level system, which manifests itself as an all-optical spin echo in nonlinear optics with two orders of optical fields saved as compared with stimulated Raman processes. This finding represents a class of optical nonlinearity induced by electromagnetic vacuum fluctuations.
Wang Jing [Department of Physics, Chinese University of Hong Kong, Shatin, N.T. (Hong Kong); Department of Physics, Tsinghua University, Beijing 100084 (China); Liu Renbao [Department of Physics, Chinese University of Hong Kong, Shatin, N.T. (Hong Kong); Zhu Bangfen [Department of Physics, Tsinghua University, Beijing 100084 (China); Institute of Advanced Study, Tsinghua University, Beijing 100084 (China); Sham, L. J. [Department of Physics, University of California-San Diego, La Jolla, California 92093-0319 (United States); Steel, D. G. [H. M. Randall Laboratory of Physics, University of Michigan, Ann Arbor, Michigan 48109 (United States)
Overview Of Electromagnetic Methods Applied In Active Volcanic Areas Of
Of Electromagnetic Methods Applied In Active Volcanic Areas Of Of Electromagnetic Methods Applied In Active Volcanic Areas Of Western United States Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: Overview Of Electromagnetic Methods Applied In Active Volcanic Areas Of Western United States Details Activities (7) Areas (2) Regions (0) Abstract: A better understanding of active volcanic areas in the United States through electromagnetic geophysical studies received foundation from the many surveys done for geothermal exploration in the 1970's. Investigations by governmental, industrial, and academic agencies include (but are not limited to) mapping of the Cascades. Long Valley/Mono area, the Jemez volcanic field, Yellowstone Park, and an area in Colorado. For one example - Mt. Konocti in the Mayacamas Mountains, California - gravity,
Development of Radio Frequency Exposure Standards
While unconfirmed claims of adverse human health effects from electromagnetic radiation date to the 1930s, development of modern safety standards did not begin until the 1952 Hirsch study of eye damage at a microwave power density of 100 mW/cm2. Early work on standards focused on microwave frequencies due to rapid development of radar and microwave communications links. In the years since 1952, radio frequency (RF) exposure standards have kept pace with those technological advancements. While refinements...
Langmuir waves (LWs) in the solar wind are generated by electron beams associated with solar flares, interplanetary shock fronts, planetary bow shocks, and magnetic holes. In principle, LWs localized as eigenmodes of density fluctuations can emit electromagnetic (EM) radiation by an antenna mechanism near the local plasma frequency f{sub p} and twice the local plasma frequency. In this work, analytic expressions are derived for the radiated electric and magnetic fields and power generated near f{sub p} by LW eigenmodes. The EM wave power emitted near f{sub p} is predicted as a function of the eigenmode length scale L, maximum electric field, driving electron beam speed, and the ambient plasma density and temperature. The escape to a distant observer of f{sub p} radiation from a localized Langmuir eigenmode is also briefly explored as a function of the plasma conditions.
Malaspina, David M. [Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, CO 80303 (United States); Cairns, Iver H. [School of Physics, University of Sydney, New South Wales 2006 (Australia); Ergun, Robert E., E-mail: firstname.lastname@example.com, E-mail: email@example.com, E-mail: firstname.lastname@example.com [Laboratory for Atmospheric and Space Physics, Department of Astrophysical and Planetary Sciences, University of Colorado, Boulder, CO 80303 (United States)
Orbit compensation for the time-varying elliptically polarized wiggler with switching frequency at 100 hz
In October 1996, the elliptically polarized wiggler, installed in the X13 straight section of the NSLS X-ray ring, was commissioned at an operating frequency of 100 hz. This wiggler generates circularly polarized photons in the energy range of 0.1 to 10 keV with AC modulation of polarization helicity. The vertical magnetic field is produced by a hybrid permanent magnet structure, and the horizontal magnetic field is generated by an electromagnet capable of switching at frequencies up to 100 hz. Here, the authors discuss the compensation of the residual vertical and horizontal orbit motion utilizing a time-domain algorithm employing a function generator to drive trim coils at the wiggler ends, and the wideband high precision orbit measurement system of the X-ray ring. The residual orbit motion has been reduced to a level below 1 micron, and the device has been run in regular operations with no negative effect on other users.
Singh, O.; Krinsky, S.
High frequency breakdown voltage
This report contains information about the effect of frequency on the breakdown voltage of an air gap at standard pressure and temperature, 76 mm Hg and O{degrees}C, respectively. The frequencies of interest are 47 MHz and 60 MHz. Additionally, the breakdown in vacuum is briefly considered. The breakdown mechanism is explained on the basis of collision and ionization. The presence of the positive ions produced by ionization enhances the field in the gap, and thus determines the breakdown. When a low-frequency voltage is applied across the gap, the breakdown mechanism is the same as that caused by the DC or static voltage. However, when the frequency exceeds the first critical value f{sub c}, the positive ions are trapped in the gap, increasing the field considerably. This makes the breakdown occur earlier; in other words, the breakdown voltage is lowered. As the frequency increases two decades or more, the second critical frequency, f{sub ce}, is reached. This time the electrons start being trapped in the gap. Those electrons that travel multiple times across the gap before reaching the positive electrode result in an enormous number of electrons and positive ions being present in the gap. The result is a further decrease of the breakdown voltage. However, increasing the frequency does not decrease the breakdown voltage correspondingly. In fact, the associated breakdown field intensity is almost constant (about 29 kV/cm).The reason is that the recombination rate increases and counterbalances the production rate, thus reducing the effect of the positive ions` concentration in the gap. The theory of collision and ionization does not apply to the breakdown in vacuum. It seems that the breakdown in vacuum is primarily determined by the irregularities on the surfaces of the electrodes. Therefore, the effect of frequency on the breakdown, if any, is of secondary importance.
Chu, Thanh Duy
Sandia National Laboratories: Electromagnetics: Main Page
Brochure Adobe Logo Related Links Pulsed Power ELECTROMAGNETIC TECHNOLOGY AT SANDIA NATIONAL LABORATORIES Electromagnetics (EM) is the study of the nature and interaction of...
Through-Barrier Electromagnetic Communication and Sensing: Advances in
Through-Barrier Electromagnetic Communication and Sensing: Advances in Through-Barrier Electromagnetic Communication and Sensing: Advances in Wideband Radio-Wave Communications and ..... Speaker(s): Farid Dowla Date: June 1, 2007 - 12:00pm Location: 90-3122 Seminar Host/Point of Contact: Mary Ann Piette (Complete seminar title is: Through-Barrier Electromagnetic Communication and Sensing: Advances in Wideband Radio-Wave Communications and Radar Imaging, Radio-Frequency (RF) Tags and Tera-Hertz (THz) Standoff Detection Spectroscopy) In many remote sensing problems there is a critical need to detect and image objects through barriers, such as buildings, with high reliability and resolution and at long ranges. A related problem is the wireless communication and geolocation of transceivers in harsh RF environments, such as in urban areas and underground caves, where
Electromagnetic (EM-60) survey in the Panther Canyon Area, Grass Valley, Nevada
Eight frequency domain electromagnetic soundings were measured over the Panther Canyon thermal anomaly in Grass Valley, Nevada. The data were collected with Lawrence Berkeley Laboratory's large moment horizontal loop system (EM-60). At the transmitter site located near the center of the thermal anomaly, square wave currents of up to 70 A were impressed into a fourturn 50 m radius coil at frequencies from 0.033 to 500 Hz. At the eight receiver sites, 0.5 to 1.5 km from the loop, magnetic fields were detected with a three-component SQUID magnetometer and vertical and radial magnetic field spectra were calculated. Data were interpreted with a computer program which fit filled spectra and associated ellipse polarization data to one-dimensional resistivity models and results were compared to interpretations from earlier dipole-dipole resistivity measurements. Comparison of these interpretations indicates fairly close agreement between the two, with both models clearly indicating the presence and dimensions of the conductivity anomaly associated with the thermal zone. Although the dc data was better able to resolve the high resistivity bedrock, the EM-data were able to resolve all major features without distortion at shorter transmitter receiver separations and in about one-third of the field time.
Wilt, M.; Goldstein, N.; Stark, M.; Haught, R.
Quasi light fields: Extending the light field to coherent radiation
Imaging technologies such as dynamic viewpoint generation are engineered for incoherent radiation using the traditional light field, and for coherent radiation using electromagnetic field theory. We present a model of ...
Accardi, Anthony J.
Graphene-based plasmonic switches at near infrared frequencies
The concept, analysis, and design of series switches for graphene-strip plasmonic waveguides at near infrared frequencies are presented. Switching is achieved by using graphene's field effect to selectively enable or forbid propagation on a section of the graphene strip waveguide, thereby allowing good transmission or high isolation, respectively. The electromagnetic modeling of the proposed structure is performed using full-wave simulations and a transmission line model combined with a matrix-transfer approach, which takes into account the characteristics of the plasmons supported by the different graphene-strip waveguide sections of the device. The performance of the switch is evaluated versus different parameters of the structure, including surrounding dielectric media, electrostatic gating and waveguide dimensions.
Gomez-Diaz, J S
Magnetic resonance as a channel of directed transmission of electromagnetic energy in animate nature
The phenomenon of magnetic resonance (either NMR or ESR) is a responce of atomic (molecular) system to the external electromagnetic effect. Electrons and nuclei, which possess magnetic moment, are the "magnetic antennas" in the biosystem "human being". They are able to receive (radiate) electromagnetic energy selectively in coordinates $H$ (magnetic field), $\
E. Ya. Fursa
Graphene-based nano-antennas for electromagnetic nanocommunications in the terahertz band
Abstract�Nanotechnology is enabling the development of devices in a scale ranging from one to a few hundred nanometers. Coordination and information sharing among these nano-devices will lead towards the development of future nanonetworks, boosting the range of applications of nanotechnology in the biomedical, environmental and military fields. Despite the major progress in nano-device design and fabrication, it is still not clear how these atomically precise machines will communicate. Recently, the advancements in graphene-based electronics have opened the door to electromagnetic communications in the nanoscale. In this paper, a new quantum mechanical framework is used to analyze the properties of Carbon Nanotubes (CNTs) as nano-dipole antennas. For this, first the transmission line properties of CNTs are obtained using the tight-binding model as functions of the CNT length, diameter, and edge geometry. Then, relevant antenna parameters such as the fundamental resonant frequency and the input impedance are calculated and compared to those of a nano-patch antenna based on a Graphene Nanoribbon (GNR) with similar dimensions. The results show that for a maximum antenna size in the order of several hundred nanometers (the expected maximum size for a nano-device), both a nano-dipole and a nano-patch antenna will be able to radiate electromagnetic waves in the terahertz band (0.1-10.0 THz). I.
Josep Miquel Jornet; Ian F. Akyildiz
Structures, systems and methods for harvesting energy from electromagnetic radiation
Methods, devices and systems for harvesting energy from electromagnetic radiation are provided including harvesting energy from electromagnetic radiation. In one embodiment, a device includes a substrate and one or more resonance elements disposed in or on the substrate. The resonance elements are configured to have a resonant frequency, for example, in at least one of the infrared, near-infrared and visible light spectra. A layer of conductive material may be disposed over a portion of the substrate to form a ground plane. An optical resonance gap or stand-off layer may be formed between the resonance elements and the ground plane. The optical resonance gap extends a distance between the resonance elements and the layer of conductive material approximately one-quarter wavelength of a wavelength of the at least one resonance element's resonant frequency. At least one energy transfer element may be associated with the at least one resonance element.
Novack, Steven D. (Idaho Falls, ID); Kotter, Dale K. (Shelley, ID); Pinhero, Patrick J. (Columbia, MO)
Energy harvesting devices for harvesting energy from terahertz electromagnetic radiation
Novack, Steven D.; Kotter, Dale K.; Pinhero, Patrick J.
Control and monitoring method and system for electromagnetic forming processes
A process, system, and improvement for a process for electromagnetic forming of a workpiece in which characteristics of the workpiece such as its geometry, electrical conductivity, quality, and magnetic permeability can be determined by monitoring the current and voltage in the workcoil. In an electromagnet forming process in which a power supply provides current to a workcoil and the electromagnetic field produced by the workcoil acts to form the workpiece, the dynamic interaction of the electromagnetic fields produced by the workcoil with the geometry, electrical conductivity, and magnetic permeability of the workpiece, provides information pertinent to the physical condition of the workpiece that is available for determination of quality and process control. This information can be obtained by deriving in real time the first several time derivatives of the current and voltage in the workcoil. In addition, the process can be extended by injecting test signals into the workcoil during the electromagnetic forming and monitoring the response to the test signals in the workcoil. 3 figs.
Kunerth, D.C.; Lassahn, G.D.
Superconductors Programs/Projects in Electromagnetics
Superconductors Programs/Projects in Electromagnetics. Superconductor Electromechanics. Contact. General Information ...
Controlled-source electromagnetic survey at Soda Lakes geothermal area, Nevada
The EM-60 system, a large-moment frequency-domain electromagnetic loop prospecting system, was operated in the Soda Lakes geothermal area, Nevada. Thirteen stations were occupied at distances ranging from 0.5-3.0 km from two transmitter sites. These yielded four sounding curves--the normalized amplitudes and phases of the vertical and radial magnetic fields as a function of frequency--at each station. In addition, two polarization ellipse parameters, ellipticity and tilt angle, were calculated at each frequency. The data were interpreted by means of a least-squares inversion procedure which fits a layered resistivity model to the data. A three-layer structure is indicated, with a near-surface 20 ohm-m layer of 100-400 m thickness, a middle 2 ohm-m layer of approximately 1 km thickness, and a basement of greater than 10 ohm-m. The models indicate a northwesterly structural strike; the top and middle layers seem to thicken from northeast to southwest. The results agree quite well with previous results of dipole-dipole and magnetotelluric (MT) surveys. The EM-60 survey provided greater depth penetration (1 to 1.5 km) than dipole-dipole, but MT far surpassed both in its depth of exploration. One advantage of EM in this area is its ease and speed of operation. Another advantage, its relative insensitivity to lateral inhomogeneities, is not as pronounced here as it would be in areas of more complex geology.
Stark, M.; Wilt, M.; Haught, J.R.; Goldstein, N.
Guidelines for Electromagnetic Interference Testing
One issue that has been problematic for new plant equipment and especially for digital instrumentation and control (I&C) systems in recent years is electromagnetic compatibility (EMC). Guidance from the Nuclear Regulatory Commission (NRC), EPRI, and various standards organizations has been evolving for many years and generally converging. However, the NRC's most recent guidance, Regulatory Guide 1.180 Revision 1, and EPRI's most recent EMI Guideline (Guidelines for Electromagnetic Interference Testing in...
Black Hole Thermodynamics and Electromagnetism
We show a strong parallel between the Hawking, Beckenstein black hole Thermodynamics and electromagnetism: When the gravitational coupling constant transform into the electromagnetic coupling constant, the Schwarzchild radius, the Beckenstein temperature, the Beckenstein decay time and the Planck mass transform to respectively the Compton wavelength, the Hagedorn temperature, the Compton time and a typical elementary particle mass. The reasons underlying this parallalism are then discussed in detail.
Burra G. Sidharth
Gene Frequency
Gene Frequency Gene Frequency Name: donna Location: N/A Country: N/A Date: N/A Question: If six fingers is a dominant human trait why do we have only five? Replies: This is simple. There are just not many genes in the human population for six fingers. Steve Sample Look in any high school biology book for what is known as Hardy-Weinberg equilibrium. These two scientists (separately) said that gene frequencies do not change much unless something in the environment selects them over other genes. In other words, unless 6 fingers somehow becomes an advantage, and five-fingered people have less of an advantage, the frequency of six fingered people in the population will not necessarily increase. This is the same reason that recessive traits don't disappear from the population. Also, six fingers is not considered attractive and they may not get as many mates. Also, more people are born with six fingers than you might imagine but just have them amputated shortly after birth.
Electromagnetic soundings over a geothermal reservoir in Dixie Valley, Nevada
An electromagnetic (EM) sounding survey was performed over a region encompassing the Dixie Valley geothermal field with the purpose of mapping the subsurface resistivity in the geothermal field and its surroundings. The EM survey consisted of 19 frequency-domain depth soundings made with the EM-60 system using three separate horizontal-loop transmitters, and was designed to explore a narrow region adjacent to the Stillwater Range to a depth of 2 to 3 k. Most sounding curves could be fitted to three-layer resistivity models. The surface layer is moderately conductive (10 to 15 ohm-m), has a maximum thickness of 500 m, and consists mainly of alluvial fan and lake sediments. More conductive zones are associated with hydrothermally altered rocks; a resistivity high may be associated with siliceous hot spring deposits. The conductive second layer (2 to 5 ohm-m) varies in thickness from 400 to 800 m and thickens toward the center of the valley. This layer probably consists of lacustrine sediments saturated with saline waters. Local resistivity lows observed in the second layer may be related to elevated subsurface temperatures. This layer may act as a cap rock for the geothermal system. Resistivities of the third layer are high (50 to 100 ohm-m) except in a narrow 5-km band paralleling the range front. This low-resistivity zone, within volcanic rocks, correlates well in depth and location with reported zones of geothermal fluid production. It also seems to correlate with the western margin of a concealed graben structure previously inferred from other geophysical data.
Far field acceleration
Far fields are propagating electromagnetic waves far from their source, boundary surfaces, and free charges. The general principles governing the acceleration of charged particles by far fields are reviewed. A survey of proposed field configurations is given. The two most important schemes, Inverse Cerenkov acceleration and Inverse free electron laser acceleration, are discussed in detail.
Fernow, R.C.
Electromagnetic Transition in Waveguide with Application to Lasers
The electromagnetic transition of two-level atomic systems in a waveguide is calculated. Compared with the result in free space, the spontaneous emission rate decrease because the phase space is smaller, and meanwhile, some resonance appears in some cases. Moreover, the influence of non-uniform electromagnetic field in a waveguide on absorption and stimulated emission is considered. Applying the results to lasers, a method to enhance the laser power is proposed. PACS codes: 42.50.ct, 42.55.Ah 1
unknown authors
On the spontaneous emission of electromagnetic radiation in the CSL model
Spontaneous photon emission in the Continuous Spontaneous Localization (CSL) model is studied one more time. In the CSL model each particle interacts with a noise field that induces the collapse of its wave function. As a consequence of this interaction, when the particle is electrically charged, it radiates. As discussed in [1], the formula for the emission rate, to first perturbative order, contains two terms: One is proportional to the Fourier component of the noise field at the same frequency as that of the emitted photon and one is proportional to the zero Fourier component of the noise field. As discussed in previous works, this second term seems unphysical. In [1], it was shown that the unphysical term disappears when the noises is confined to a bounded region and the final particle's state is a wave packet. Here we investigate the origin of the unphysical term and why it vanishes according to the previous prescription. For this purpose, the electrodynamic part of the equation of motion is solved exactly while the part due to the noise is treated perturbatively. We show that the unphysical term is connected to exponentially decaying function of time which dies out in the large time limit, however, approximates to 1 in the first perturbative order in the electromagnetic field.
S. Donadi; A. Bassi; D. -A. Deckert
Steven Weinberg, Weak Interactions, and Electromagnetic Interactions
Steven Weinberg and Steven Weinberg and Weak and Electromagnetic Interactions Resources with Additional Information Steven Weinberg Courtesy Dr. Steven Weinberg Steven "Weinberg is a professor of physics and astronomy at UT [The University of Texas] Austin and is founding director of the Theory Group in the College of Natural Sciences. [He is] well known for his development of a field theory that unifies the electromagnetic and weak nuclear forces, and for other major contributions to physics and cosmology ... Weinberg's work has been honored with numerous prizes, including the Nobel Prize in Physics in 1979 and the National Medal of Science in 1991. Weinberg is the author of the prize-winning book The First Three Minutes: A Modern View of the Origin of the Universe (which has been translated into 22 foreign languages) as well as Gravitation and Cosmology, The Discovery of Subatomic Particles, Dreams of a Final Theory and The Quantum Theory of Fields. ... Weinberg was the recipient of the Scientist as Poet prize from Rockefeller University for "extraordinary achievements in conveying - with passionate clarity - the ideas, history, explanatory power and aesthetic dimensions of fundamental physics." The citation mentioned two of Weinberg's books.
Phenomenon of parametric trapping of electromagnetic waves in an inhomogeneous plasma
A theory is developed of absolute parametric aperiodic instability in a spatially inhomogeneous plasma, when the electromagnetic waves generated in the plasma are trapped by the plasma near the peaks of the pumping-wave field.
Silin, V.P.; Starodub, A.N.
Radio frequency sustained ion energy
Electromagnetic (E.M.) energy injection method and apparatus for producing and sustaining suprathermal ordered ions in a neutral, two-ion-species, toroidal, bulk equilibrium plasma. More particularly, the ions are produced and sustained in an ordered suprathermal state of existence above the average energy and velocity of the bulk equilibrium plasma by resonant rf energy injection in resonance with the natural frequency of one of the ion species. In one embodiment, the electromagnetic energy is injected to clamp the energy and velocity of one of the ion species so that the ion energy is increased, sustained, prolonged and continued in a suprathermal ordered state of existence containing appreciable stored energy that counteracts the slowing down effects of the bulk equilibrium plasma drag. Thus, selective deuteron absorption may be used for ion-tail creation by radio-frequency excitation alone. Also, the rf can be used to increase the fusion output of a two-component neutral injected plasma by selective heating of the injected deuterons.
Jassby, Daniel L. (Princeton, NJ); Hooke, William M. (Princeton, NJ)
Application of natural electromagnetic field methods (magnetotellurics/geomagnetic variations) to exploring for energy resources: development of a broad-band data acquisition/processing facility. Topical report, May 1, 1979-April 30, 1980
Progress is summarized in the following fields: a review of the present state of knowledge of the deep thermal regimes associated with major rift systems of the world, field studies of several major tectonomagmatic systems, and design and testing of new magnetotelluric/geomagnetic variation field system for studying thermal regimes in the continental crust. (MHR)
Hermance, J.F.
As part of the 200-PO-1 Phase I geophysical surveys, Fugro Airborne Surveys was contracted to collect airborne electromagnetic (EM) and magnetic surveys of the Hanford Site 600 Area. Two helicopter survey systems were used with the HeliGEOTEM{reg_sign} time domain portion flown between June 19th and June 20th, 2008, and the RESOLVE{reg_sign} frequency domain portion was flown from June 29th to July 1st, 2008. Magnetic data were acquired contemporaneously with the electromagnetic surveys using a total-field cesium vapor magnetometer. Approximately 925 line kilometers (km) were flown using the HeliGEOTEM{reg_sign} II system and 412 line kilometers were flown using the RESOLVE{reg_sign} system. The HeliGEOTEM system has an effective penetration of roughly 250 meters into the ground and the RESOLVE system has an effective penetration of roughly 60 meters. Acquisition parameters and preliminary results are provided in SGW-39674, Airborne Electromagnetic Survey Report, 200-PO-1 Groundwater Operable Unit, 600 Area, Hanford Site. Airborne data are interpreted in this report in an attempt to identify areas of likely preferential groundwater flow within the aquifer system based on the presence of paleochannels or fault zones. The premise for the interpretation is that coarser-grained intervals have filled in scour channels created by episodic catastrophic flood events during the late Pleistocene. The interpretation strategy used the magnetic field anomaly data and existing bedrock maps to identify likely fault or lineament zones. Combined analysis of the magnetic, 60-Hz noise monitor, and flight-altitude (radar) data were used to identify zones where EM response is more likely due to cultural interference and or bedrock structures. Cross-sectional and map view presentations of the EM data were used to identify more electrically resistive zones that likely correlate with coarser-grained intervals. The resulting interpretation identifies one major northwest-southeast trending preferential flowpath with several minor units running along a similar trend. This presumed path of preferential flow is compared with the tritium concentration levels observed for the 600 Area. Analysis of the magnetic field data shows the location of potential bedrock faults and lineaments which may influence the horizontal and vertical flow of water. Faults lying within, or in the vicinity of preferential groundwater flow paths may allow flow into or out of the otherwise confined basalt layers.
Electromagnetic Imaging of CO2 Sequestration at an Enhanced Oil Recovery Site
Lawrence Livermore National Laboratory (LLNL) is currently involved in a long term study using time-lapse multiple frequency electromagnetic (EM) characterization at a waterflood enhanced oil recovery (EOR) site in California operated by Chevron Heavy Oil Division in Lost Hills, California (Figure 1). The petroleum industry's interest and the successful imaging results from this project suggest that this technique be extended to monitor CO{sub 2} sequestration at an EOR site also operated by Chevron. The impetus for this study is to develop the ability to image subsurface injected CO{sub 2} during EOR processes while simultaneously discriminating between pre-existing petroleum and water deposits. The goals of this study are to combine laboratory and field methods to image a pilot CO{sub 2} sequestration EOR site using the cross-borehole EM technique, improve the inversion process in CO{sub 2} studies by coupling results with petrophysical laboratory measurements, and focus on new gas interpretation techniques. In this study we primarily focus on how joint field and laboratory results can provide information on subsurface CO{sub 2} detection, CO{sub 2} migration tracking, and displacement of petroleum and water over time. This study directly addresses national energy issues in two ways: (1) the development of field and laboratory techniques to improve in-situ analysis of oil and gas enhanced recovery operations and, (2) this research provides a tool for in-situ analysis of CO{sub 2} sequestration, an international technical issue of growing importance.
Kirkendall, B.; Roberts, J.
Electromagnetic Imaging of C02 Sequestration at an Enhanced Oil Recovery Site
Lawrence Livermore National Laboratory (LLNL) is currently involved in a long term study using time-lapse multiple frequency electromagnetic (EM) characterization at a waterflood enhanced oil recovery (EOR) site in California operated by Chevron Heavy Oil Division in Lost Hills, California. The petroleum industry's interest and the successful imaging results from this project suggest that this technique be extended to monitor CO{sub 2} sequestration at an EOR site also operated by Chevron. The impetus for this study is to develop the ability to image subsurface injected CO{sub 2} during EOR processes while simultaneously discriminating between pre-existing petroleum and water deposits. The goals of this study are to combine laboratory and field methods to image a pilot CO{sub 2} sequestration EOR site using the cross-borehole EM technique, improve the inversion process in CO{sub 2} studies by coupling results with petrophysical laboratory measurements, and focus on new gas interpretation techniques. In this study we primarily focus on how joint field and laboratory results can provide information on subsurface CO{sub 2} detection, CO{sub 2} migration tracking, and displacement of petroleum and water over time. This study directly addresses national energy issues in two ways: (1) the development of field and laboratory techniques to improve in-situ analysis of oil and gas enhanced recovery operations and, (2) this research provides a tool for in-situ analysis of CO{sub 2} sequestration, an international technical issue of growing importance.
Kirkendall, B; Roberts, J
Questions and Answers - I am creating an electromagnet for my school's
Do you know whatan electromagnet is? Do you know what<br>an electromagnet is? Previous Question (Do you know what an electromagnet is?) Questions and Answers Main Index Next Question (Why does adding coils to an electromagnet make it stronger?) Why does adding coils to anelectromagnet make it stronger? I am creating an electromagnet for my school's science fair project. Does the shape of the iron core make a difference? Is solid copper wire better than stranded wire? Is copper wire best, or is another wire better? Should the wire be insulated or bare? What can I do to get the most current out of a battery? Yes, the shape of the iron core does matter. The more complete the circuit formed by the iron, the more field that you will get for a given coil and current. The best way to do a simple magnet is to have an iron core shaped
Airborne electromagnetic surveys as a reconnaissance technique...
electromagnetic surveys as a reconnaissance technique for geothermal exploration Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Conference Proceedings: Airborne...
Sympathetic Electromagnetically-Induced-Transparency Laser ...
Page 1. Sympathetic Electromagnetically-Induced-Transparency Laser Cooling of Motional Modes in an Ion Chain Y. Lin ...
Unification of Gravity and Electromagnetism Revisited
Unification of gravity and electromagnetism based on a theory with an affine non-symmetric connection $\\Gamma^\\lambda_{\\mu\
Partha Ghose
Current Sheet Canting in Pulsed Electromagnetic Accelerators
Current Sheet Canting in Pulsed Electromagnetic Accelerators Thomas Edward Markusic A DISSERTATION #12;Current Sheet Canting in Pulsed Electromagnetic Accelerators Prepared by: Thomas Edward Markusic of current sheet canting in pulsed electromagnetic accelerators is the de- parture of the plasma sheet
Electromagnetic and nuclear radiation detector using micromechanical sensors
Electromagnetic and nuclear radiation is detected by micromechanical sensors that can be coated with various interactive materials. As the micromechanical sensors absorb radiation, the sensors bend and/or undergo a shift in resonance characteristics. The bending and resonance changes are detected with high sensitivity by any of several detection methods including optical, capacitive, and piezoresistive methods. Wide bands of the electromagnetic spectrum can be imaged with picoJoule sensitivity, and specific absorptive coatings can be used for selective sensitivity in specific wavelength bands. Microcantilevers coated with optical cross-linking polymers are useful as integrating optical radiation dosimeters. Nuclear radiation dosimetry is possible by fabricating cantilevers from materials that are sensitive to various nuclear particles or radiation. Upon exposure to radiation, the cantilever bends due to stress and its resonance frequency shifts due to changes in elastic properties, based on cantilever shape and properties of the coating.
Thundat, Thomas G. (Knoxville, TN); Warmack, Robert J. (Knoxville, TN); Wachter, Eric A. (Oak Ridge, TN)
Vlf Electromagnetic Investigations Of The Crater And Central Dome Of Mount
Vlf Electromagnetic Investigations Of The Crater And Central Dome Of Mount Vlf Electromagnetic Investigations Of The Crater And Central Dome Of Mount St Helens, Washington Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: Vlf Electromagnetic Investigations Of The Crater And Central Dome Of Mount St Helens, Washington Details Activities (1) Areas (1) Regions (0) Abstract: A very low frequency (VLF) electromagnetic induction survey in the crater of Mount St. Helens has identified several electrically conductive structures that appear to be associated with thermal anomalies and ground water within the crater. The most interesting of these conductive structures lies beneath the central dome. It is probably a partial melt of dacite similar to that comprising the June 1981 lobe of the central dome. Author(s): James N. Towle
On the design of experiments to study extreme field limits
We propose experiments on the collision of high intensity electromagnetic pulses with electron bunches and on the collision of multiple electromagnetic pulses for studying extreme field limits in the nonlinear interaction of electromagnetic waves. The effects of nonlinear QED will be revealed in these laser plasma experiments.
Bulanov, S. S.; Chen, M.; Schroeder, C. B.; Esarey, E.; Leemans, W. P.; Bulanov, S. V.; Esirkepov, T. Zh.; Kando, M.; Koga, J. K.; Zhidkov, A. G.; Chen, P.; Mur, V. D.; Narozhny, N. B.; Popov, V. S.; Thomas, A. G. R.; Korn, G. [University of California, Berkeley, California 94720 (United States); Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States) and University of California, Berkeley, California 94720 (United States); Kansai Photon Science Institute, JAEA, Kizugawa, Kyoto 619-0215 (Japan); Osaka University, Osaka 565-0871 (Japan); Leung Center for Cosmology and Particle Astrophysics, National Taiwan University, Taipei 10617, Taiwan (China); Moscow Engineering Physics Institute (State University), Moscow 115409 (Russian Federation); Institute of Theoretical and Experimental Physics, Moscow 117218 (Russian Federation); University of Michigan, Ann Arbor, Michigan 48103 (United States); Max-Planck-Institut fur Quantenoptik, Garching 85748 (Germany) and ELI Beamline Facility, Institute of Physics, Czech Academy of Sciences, Prague 18221 (Czech Republic)
Radiative processes: Potentials or Fields?
In this work we prove that the transition amplitudes of processes involving the emission of one or more real photons is gauge invariant through terms that are always proportional to the electromagnetic field tensor.
Moreno, Matias [Instituto de Fisica, Universidad Nacional Autonoma de Mexico, Mexico, D.F. 04510 (Mexico); Lopez Castro, Gabriel [Departamento de Fisica, Centro de Investigacion y Estudios Avanzados, Mexico, D.F. (Mexico)
Calibration case study of natural source electromagnetic array data recorded over a well in Oregon
Natural field electromagnetic acquired conventionally, at a number of sparsely spaced single sites, can suffer from spatial aliasing and significant distortive shallow effects which severely limit its geophysical applications. A new mode of data acquisition which measures the electric field continuously along a profile has been developed by F.X. Boxtick. These data can be processed to remove shallow effects while maintaining the deep penetration characteristics of the natural electromagnetic (EM) fields. Processing and modeling techniques for such data are discussed and demonstrated on both synthetic and field data. Very good agreement with actual borehole data is demonstrated.
Shoemaker, C.L.; Shoham, Y.; Hockey, R.
A quaternionic unification of electromagnetism and hydrodynamics
We have derived energy conservation equations from the quaternionic Newton's law that is compatible with Lorentz transformation. This Newton's law yields directly the Euler equation and other relations governing the fluid motion. With this formalism, the pressure contributes positively to the dynamics of the system in the same way mass does. Hydrodynamic equations are derived from Maxwell's equations by adopting an electromagnetohydrodynamics analogy. In this analogy the hydroelectric field is related to the local acceleration of the fluid and the Lorentz gauge is related to the incompressible fluid condition. An analogous Lorentz gauge in hydrodynamics is proposed. We have shown that the vorticity of the fluid is developed whenever the particle local acceleration of the fluid deviates from the velocity direction. We have shown that Lorentz force in electromagnetism corresponds to Euler force for fluids. Moreover, we have obtained a Faraday-like law and Ampere's -like law in Hydrodynamics.
Arbab, Arbab I
We have derived energy conservation equations from the quaternionic Newton's law that is compatible with Lorentz transformation. This Newton's law yields directly the Euler equation and other equations governing the fluid motion. With this formalism, the pressure contributes positively to the dynamics of the system in the same way mass does. Hydrodynamic equations are derived from Maxwell's equations by adopting an electromagnetohydrodynamics (EMH) analogy. In this analogy the hydroelectric field is related to the local acceleration of the fluid and the Lorentz gauge is related to the incompressible fluid condition. An analogous Lorentz gauge in hydrodynamics is proposed. We have shown that the vorticity of the fluid is developed whenever the particle local acceleration of the fluid deviates from the velocity direction. We have also shown that Lorentz force in electromagnetism corresponds to Euler force in fluids. Moreover, we have obtained Gauss's, Faraday's and Ampere's -like laws in Hydrodynamics.
Arbab I. Arbab
Ground Electromagnetic Techniques | Open Energy Information
Ground Electromagnetic Techniques Ground Electromagnetic Techniques (Redirected from Ground Electromagnetic Methods) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Technique: Ground Electromagnetic Techniques Details Activities (0) Areas (0) Regions (0) NEPA(0) Exploration Technique Information Exploration Group: Geophysical Techniques Exploration Sub Group: Electrical Techniques Parent Exploration Technique: Electromagnetic Techniques Information Provided by Technique Lithology: Rock composition, mineral and clay content Stratigraphic/Structural: Detection of permeable pathways, fracture zones, faults Hydrological: Resistivity influenced by porosity, grain size distribution, permeability, fluid saturation, fluid type and phase state of the pore water Thermal: Resistivity influenced by temperature
Definition: Electromagnetic Profiling Techniques | Open Energy Information
Electromagnetic Profiling Techniques Electromagnetic Profiling Techniques Jump to: navigation, search Dictionary.png Electromagnetic Profiling Techniques Electromagnetic profiling techniques map lateral variations in subsurface resistivity.[1] View on Wikipedia Wikipedia Definition Exploration geophysics is the applied branch of geophysics which uses surface methods to measure the physical properties of the subsurface Earth, along with the anomalies in these properties, in order to detect or infer the presence and position of ore minerals, hydrocarbons, geothermal reservoirs, groundwater reservoirs, and other geological structures. Exploration geophysics is the practical application of physical methods (such as seismic, gravitational, magnetic, electrical and electromagnetic) to measure the physical properties of rocks, and in particular, to detect
Electromagnetic Sounding Techniques | Open Energy Information
Electromagnetic Sounding Techniques Electromagnetic Sounding Techniques (Redirected from Electromagnetic Sounding Methods) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Technique: Electromagnetic Sounding Techniques Details Activities (1) Areas (1) Regions (0) NEPA(0) Exploration Technique Information Exploration Group: Geophysical Techniques Exploration Sub Group: Electrical Techniques Parent Exploration Technique: Ground Electromagnetic Techniques Information Provided by Technique Lithology: Rock composition, mineral and clay content Stratigraphic/Structural: Detection of permeable pathways, fracture zones, faults Hydrological: Resistivity influenced by porosity, grain size distribution, permeability, fluid saturation, fluid type and phase state of the pore water
Generation and detection of gravitational waves at microwave frequencies by means of a superconducting two-body system
The 2-body system of a superconducting sphere levitated in the magnetic field generated by a persistent current in a superconducting ring, can possibly convert gravitational waves into electromagnetic waves, and vice versa. Faraday's law of induction implies that the time-varying distance between the sphere and the ring caused by the tidal force of an incident gravitational wave induces time-varying electrical currents, which are the source of an electromagnetic wave at the same frequency as the incident gravitational wave. At sufficiently low temperatures, the internal degrees of freedom of the superconductors are frozen out because of the superconducting energy gap, and only external degrees of freedom, which are coupled to the radiation fields, remain. Hence this wave-conversion process is loss-free and therefore efficient, and by time-reversal symmetry, so is the reverse process. A Hertz-like experiment at microwave frequencies should therefore be practical to perform. This would open up observations of the gravitational-wave analog of the Cosmic Microwave Background from the extremely early Big Bang, and also communications directly through the interior of the Earth.
Raymond Y. Chiao
Questions and Answers - Which jobs use electromagnets?
does adding coils to anelectromagnet make it stronger? does adding coils to an<br>electromagnet make it stronger? Previous Question (Why does adding coils to an electromagnet make it stronger?) Questions and Answers Main Index Next Question (Why is a non-permanent, but long lasting, magnet called a permanent magnet?) Why is a non-permanent, but long lasting,magnet called a permanent magnet? Which jobs use electromagnets? In today's world almost all jobs other than a goat herder use some type of electromagnet. They are everywhere. Electric motors are a type of electromagnet. Cars have dozens of electromagnets that move things or generate electricity. There are all sorts of interesting applications for larger electromagnets. The most obvious and biggest example is electricity. There are some interesting applications like dumping shredded garbage
External Time-Varying Fields and Electron Coherence
The effect of time-varying electromagnetic fields on electron coherence is investigated. A sinusoidal electromagnetic field produces a time varying Aharonov-Bohm phase. In a measurement of the interference pattern which averages over this phase, the effect is a loss of contrast. This is effectively a form of decoherence. We calculate the magnitude of this effect for various electromagnetic field configurations. The result seems to be sufficiently large to be observable.
Jen-Tsung Hsiang; L. H. Ford
Generator On-Line Monitoring and Condition Assessment, Partial Discharge and Electromagnetic Interference
On-line partial discharge (PD) and electromagnetic interference (EMI) analysis systems have been promoted as a means to assess the condition of turbine-driven generator stator winding insulation systems. Although PD is a time-domain measurement and EMI measures activity with a frequency scan, both techniques still evaluate the same phenomenon -- high-frequency currents that flow as a result of electrical (partial) discharges occurring within the structure. This report documents EPRI's ongoing initiative ...
Electromagnetic Techniques | Open Energy Information
form form View source History View New Pages Recent Changes All Special Pages Semantic Search/Querying Get Involved Help Apps Datasets Community Login | Sign Up Search Page Edit with form History Facebook icon Twitter icon » Electromagnetic Techniques Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Technique: Electromagnetic Techniques Details Activities (0) Areas (0) Regions (0) NEPA(5) Exploration Technique Information Exploration Group: Geophysical Techniques Exploration Sub Group: Electrical Techniques Parent Exploration Technique: Electrical Techniques Information Provided by Technique Lithology: Rock composition, mineral and clay content Stratigraphic/Structural: Detection of permeable pathways, fracture zones, faults Hydrological: Resistivity influenced by porosity, grain size distribution, permeability, fluid saturation, fluid type and phase state of the pore water
We investigate the effects of a slowly rotating compact gravitational source on plasma oscillations using the gravitoelectromagnetic approximation to General Relativity. It is shown that there is a shift in the plasma frequency and hence in the refractive index of the plasma due to the gravitomagnetic force. Estimates for the difference in frequency of radially transmitted electromagnetic signals are given for typical compact star candidates. 1
Time and Frequency Portal
NIST Home > Time and Frequency Portal. Time and Frequency Portal. Programs and Projects. CODATA values of the fundamental constants ...
Self-organization of large-scale ULF electromagnetic wave structures in their interaction with nonuniform zonal winds in the ionospheric E region
A study is made of the generation and subsequent linear and nonlinear evolution of ultralow-frequency planetary electromagnetic waves in the E region of a dissipative ionosphere in the presence of a nonuniform zonal wind (a sheared flow). Hall currents flowing in the E region and such permanent global factors as the spatial nonuniformity of the geomagnetic field and of the normal component of the Earth's angular velocity give rise to fast and slow planetary-scale electromagnetic waves. The efficiency of the linear amplification of planetary electromagnetic waves in their interaction with a nonuniform zonal wind is analyzed. When there are sheared flows, the operators of linear problems are non-self-conjugate and the corresponding eigenfunctions are nonorthogonal, so the canonical modal approach is poorly suited for studying such motions and it is necessary to utilize the so-called nonmodal mathematical analysis. It is shown that, in the linear evolutionary stage, planetary electromagnetic waves efficiently extract energy from the sheared flow, thereby substantially increasing their amplitude and, accordingly, energy. The criterion for instability of a sheared flow in an ionospheric medium is derived. As the shear instability develops and the perturbation amplitude grows, a nonlinear self-localization mechanism comes into play and the process ends with the self-organization of nonlinear, highly localized, solitary vortex structures. The system thus acquires a new degree of freedom, thereby providing a new way for the perturbation to evolve in a medium with a sheared flow. Depending on the shape of the sheared flow velocity profile, nonlinear structures can be either purely monopole vortices or vortex streets against the background of the zonal wind. The accumulation of such vortices can lead to a strongly turbulent state in an ionospheric medium.
Aburjania, G. D. [Tbilisi State University, I. Vekua Institute of Applied Mathematics (Georgia); Chargazia, Kh. Z. [Nodia Institute of Geophysics (Georgia)
On the Time Reversal Invariance of Classical Electromagnetic Theory
David Albert claims that classical electromagnetic theory is not time reversal invariant. He acknowledges that all physics books say that it is, but claims they are "simply wrong" because they rely on an incorrect account of how the time reversal operator acts on magnetic fields. On that account, electric fields are left intact by the operator, but magnetic fields are inverted. Albert sees no reason for the asymmetric treatment, and insists that neither field should be inverted. I argue, to the contrary, that the inversion of magnetic fields makes good sense and is, in fact, forced by elementary geometric considerations. I also suggest a way of thinking about the time reversal invariance of classical electromagnetic theory -- one that makes use of the invariant four-dimensional formulation of the theory -- that makes no reference to magnetic fields at all. It is my hope that it will be of interest in its own right, Albert aside. It has the advantage that it allows for arbitrary curvature in the background spacetime structure, and is therefore suitable for the framework of general relativity. The only assumption one needs is temporal orientability.
David B. Malament
Electromagnetic Transients Program (EMTP) Application Guide
The electromagnetic transients program is a versatile computer program that utilities worldwide use to analyze high-speed power system transients. This application guide provides procedures and data to assist engineers experienced in electromagnetic transient analysis based on EMTP.BackgroundThe electromagnetic transients program (EMTP), developed in the early 1970s by the Bonneville Power Administration (BPA), has been widely used for transient analysis. To ...
Category:Electromagnetic Sounding Techniques | Open Energy Information
Electromagnetic Sounding Techniques Electromagnetic Sounding Techniques Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Geothermalpower.jpg Looking for the Electromagnetic Sounding Techniques page? For detailed information on Electromagnetic Sounding Techniques, click here. Category:Electromagnetic Sounding Techniques Add.png Add a new Electromagnetic Sounding Techniques Technique Subcategories This category has only the following subcategory. M [×] Magnetotelluric Techniques 1 pages Pages in category "Electromagnetic Sounding Techniques" The following 2 pages are in this category, out of 2 total. M Magnetotelluric Techniques T Time-Domain Electromagnetics Retrieved from "http://en.openei.org/w/index.php?title=Category:Electromagnetic_Sounding_Techniques&oldid=689837"
Pulsed electromagnetic acceleration of exploded wire plasmas
A simple analysis of the dynamic state of a current-conducting high-density plasma column, resulting from an exploded wire between the conductors of a rail-gun accelerator or one or more wires strung between the anode and cathode conductors in a pulsed-power generator diode, is given on the basis of a one-dimensional magnetohydrodynamics model. Spatial distributions of the current density, magnetic field, temperature, and particle density are calculated as well as the temporal current, voltage, and impedance histories. The model self-consistently treats the accelerator load transition through its solid, melt, vapor, and plasma states in the presence of its supply source and feed network. Once formed and accelerated, the plasma state calculations show expansion cooling across the self-induced magnetic field if the Bennett condition is not satisfied. The model predictions are compared to two experimental situations. The first involves the delivery of some hundreds of Joules of stored energy to the wire load. For this case, good agreement between the calculated and observed plasma state is obtained. The second situation involves the delivery of many thousands of Joules to the wire load. For this case and dependent upon the wire mass, diameter, number of wires exploded, their separation, and the pulsed energy electrical wave shapes, the magnetohydrodynamic results can be qualitatively incorrect. The necessity of an electromagnetic particle simulation approach is indicated in order to resolve the magnetic rope-like structure and filamentation observed in the very energetic plasmas.
Peratt, A.L.; Koert, P.
Time-Domain Electromagnetics | Open Energy Information
Time-Domain Electromagnetics Time-Domain Electromagnetics Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Technique: Time-Domain Electromagnetics Details Activities (10) Areas (10) Regions (0) NEPA(0) Exploration Technique Information Exploration Group: Geophysical Techniques Exploration Sub Group: Electrical Techniques Parent Exploration Technique: Electromagnetic Sounding Techniques Information Provided by Technique Lithology: Detection of rock units or geological features with contrasting apparent resistivity. Stratigraphic/Structural: Structural information may be inferred from TDEM data. Hydrological: Hydrological information such as depth to groundwater table may be determined. Thermal: Extent of hydrothermal alteration mineralogy may be inferred. Cost Information
Algebraic sub-structuring for electromagnetic applications
Li, I. Malik, W. M i , C. Ng, and M . Wolf. ElectromagneticP. Husbands, and E. G. Ng. An Alge- braic Sub-structuring
Definition: Electromagnetic Sounding Techniques | Open Energy...
Sounding Techniques Electromagnetic soundings aim to map the distribution of electrical resistivity as a function of depth.1 References http:www.amazon.com...
22.105 Electromagnetic Interactions, Fall 1998
Principles and applications of electromagnetism, starting from Maxwell's equations, with emphasis on phenomena important to nuclear engineering and radiation sciences. Solution methods for electrostatic and magnetostatic ...
Hutchinson, I. H. (Ian H.)
Ground Electromagnetic Techniques Ground Electromagnetic Techniques Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Technique: Ground Electromagnetic Techniques Details Activities (0) Areas (0) Regions (0) NEPA(0) Exploration Technique Information Exploration Group: Geophysical Techniques Exploration Sub Group: Electrical Techniques Parent Exploration Technique: Electromagnetic Techniques Information Provided by Technique Lithology: Rock composition, mineral and clay content Stratigraphic/Structural: Detection of permeable pathways, fracture zones, faults Hydrological: Resistivity influenced by porosity, grain size distribution, permeability, fluid saturation, fluid type and phase state of the pore water Thermal: Resistivity influenced by temperature Dictionary.png
Crosswell Electromagnetic Resistivity Imaging: Illuminating the Reservior |
Page Page Edit with form History Facebook icon Twitter icon » Crosswell Electromagnetic Resistivity Imaging: Illuminating the Reservior Jump to: navigation, search OpenEI Reference LibraryAdd to library Web Site: Crosswell Electromagnetic Resistivity Imaging: Illuminating the Reservior Published Middle East Asia Reservior Reviiew, 2006 DOI Not Provided Check for DOI availability: http://crossref.org Online Internet link for Crosswell Electromagnetic Resistivity Imaging: Illuminating the Reservior Citation Crosswell Electromagnetic Resistivity Imaging: Illuminating the Reservior [Internet]. 2006. Middle East Asia Reservior Reviiew. [cited 2013/10/22]. Available from: http://www.slb.com/~/media/Files/resources/mearr/num7/illuminating_reservoir.pdf Retrieved from
Electromagnetic Sounding Techniques Electromagnetic Sounding Techniques Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Technique: Electromagnetic Sounding Techniques Details Activities (1) Areas (1) Regions (0) NEPA(0) Exploration Technique Information Exploration Group: Geophysical Techniques Exploration Sub Group: Electrical Techniques Parent Exploration Technique: Ground Electromagnetic Techniques Information Provided by Technique Lithology: Rock composition, mineral and clay content Stratigraphic/Structural: Detection of permeable pathways, fracture zones, faults Hydrological: Resistivity influenced by porosity, grain size distribution, permeability, fluid saturation, fluid type and phase state of the pore water Thermal: Resistivity influenced by temperature
Electromagnetic Profiling Techniques | Open Energy Information
Electromagnetic Profiling Techniques Electromagnetic Profiling Techniques Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Technique: Electromagnetic Profiling Techniques Details Activities (0) Areas (0) Regions (0) NEPA(0) Exploration Technique Information Exploration Group: Geophysical Techniques Exploration Sub Group: Electrical Techniques Parent Exploration Technique: Ground Electromagnetic Techniques Information Provided by Technique Lithology: Rock composition, mineral and clay content Stratigraphic/Structural: Detection of permeable pathways, fracture zones, faults Hydrological: Resistivity influenced by porosity, grain size distribution, permeability, fluid saturation, fluid type and phase state of the pore water Thermal: Resistivity influenced by temperature
On electromagnetic induction in electric conductors
Experimental validation of the Faraday's law of electromagnetic induction (EMI) is performed when an electromotive force is generated in thin copper turns, located inside a large magnetic coil. It has been established that the electromotive force (emf) value should be dependent not only on changes of the magnetic induction flux through a turn and on symmetry of its crossing by magnetic power lines also. The law of EMI is applicable in sufficient approximation in case of the changes of the magnetic field near the turn are symmetrical. Experimental study of the induced emf in arcs and a direct section of the conductor placed into the variable field has been carried out. Linear dependence of the induced emf on the length of the arc has been ascertained in case of the magnetic field distribution symmetry about it. Influence of the magnetic field symmetry on the induced emf in the arc has been observed. The curve of the induced emf in the direct section over period of current pulse is similar to this one for the turns and arcs. The general law of EMI for a curvilinear conductor has been deduced. Calculation of the induced emf in the turns wrapped over it and comparison with the experimental data has been made. The proportionality factor has been ascertained for the law. Special conditions have been described, when the induced emf may not exist in the presence of inductive current. Theoretical estimation of the inductive current has been made at a induced low voltage in the turn. It has been noted the necessity to take into account the concentration of current carriers in calculation of the induced emf in semiconductors and ionized conductors.
Alexander I. Korolev
Low frequency indoor radiolocation
This thesis concerns the application of electromagnetic wave propagation to the problem of indoor radiolocation. Determining the location of people and objects relative to their environment is crucial for asset tracking, ...
Reynolds, Matthew S. (Matthew Stephen), 1975-
Electromagnetic weak turbulence theory revisited
The statistical mechanical reformulation of weak turbulence theory for unmagnetized plasmas including fully electromagnetic effects was carried out by Yoon [Phys. Plasmas 13, 022302 (2006)]. However, the wave kinetic equation for the transverse wave ignores the nonlinear three-wave interaction that involves two transverse waves and a Langmuir wave, the incoherent analogue of the so-called Raman scattering process, which may account for the third and higher-harmonic plasma emissions. The present paper extends the previous formalism by including such a term.
Yoon, P. H. [IPST, University of Maryland, College Park, Maryland 20742 (United States); Ziebell, L. F. [Instituto de Fisica, UFRGS, Porto Alegre, RS (Brazil); Gaelzer, R.; Pavan, J. [Instituto de Fisica e Matematica, UFPel, Pelotas, RS (Brazil)
Compact orthogonal NMR field sensor
A Compact Orthogonal Field Sensor for emitting two orthogonal electro-magnetic fields in a common space. More particularly, a replacement inductor for existing NMR (Nuclear Magnetic Resonance) sensors to allow for NMR imaging. The Compact Orthogonal Field Sensor has a conductive coil and a central conductor electrically connected in series. The central conductor is at least partially surrounded by the coil. The coil and central conductor are electrically or electro-magnetically connected to a device having a means for producing or inducing a current through the coil and central conductor. The Compact Orthogonal Field Sensor can be used in NMR imaging applications to determine the position and the associated NMR spectrum of a sample within the electro-magnetic field of the central conductor.
Gerald, II, Rex E. (Brookfield, IL); Rathke, Jerome W. (Homer Glen, IL)
Determination of electric field, magnetic field, and electric current distributions of infrared optical antennas: A nano-optical vector network analyzer
In addition to the electric field E(r), the associated magnetic field H(r) and current density J(r) characterize any electromagnetic device, providing insight into antenna coupling and mutual impedance. We demonstrate the optical analogue of the radio frequency vector network analyzer implemented in interferometric homodyne scattering-type scanning near-field optical microscopy (s-SNOM) for obtaining E(r), H(r), and J(r). The approach is generally applicable and demonstrated for the case of a linear coupled-dipole antenna in the mid-infrared. The determination of the underlying 3D vector electric near-field distribution E(r) with nanometer spatial resolution and full phase and amplitude information is enabled by the design of probe tips with selectivity with respect to E-parallel and E-perpendicular fabricated by focused ion-beam milling and nano-CVD.
Olmon, Robert L; Krenz, Peter M; Lail, Brian A; Saraf, Laxmikant V; Boreman, Glenn D; Raschke, Markus B
On kinetic description of electromagnetic processes in a quantum plasma
A nonlinear kinetic equation for nonrelativistic quantum plasma with electromagnetic interaction of particles is obtained in the Hartree's mean-field approximation. It is cast in a convenient form of Vlasov-Boltzmann-type equation with "quantum interference integral", that allows for relatively straightforward modification of existing classical Vlasov codes to incorporate quantum effects (quantum statistics and quantum interference of overlapping particles wave functions), without changing the bulk of the codes. Such modification (upgrade) of existing Vlasov codes may provide a direct and effective path to numerical simulations of nonlinear electrostatic and electromagnetic phenomena in quantum plasmas, especially of processes where kinetic effects are important (e.g., modulational interactions and stimulated scattering phenomena involving plasma modes at short wavelengths or high-order kinetic modes, dynamical screening and interaction of charges in quantum plasma, etc.) Moreover, numerical approaches involv...
Tyshetskiy, Y O; Kompaneets, R
Coupled Electromagnetic and Thermal Modeling of Microwave Tissue Processing
This study deals with 3D finite element modeling of microwave tissue processing using Comsol software 4.0. Maxwell�s equations are coupled with heat conduction equation to determine electromagnetic field distribution and temperature profile within tissue sample in a reagent inside a domestic microwave oven. The microwave power generation term is calculated. Also, temperature distribution obtained is compared with experimental point measurements recorded in the centre of the tissue using a shielded K type thermocouple. Good agreement is found between numerical and experimental data. The effect of size of both reagent and tissue as well as tissue type on microwave heating patterns within tissue sample is investigated. Studies shows that the reagent volume has greater effect than other factors. The results of the study is considered as a basic foundation for development of coupled electromagnetic thermal models of microwave heating of tissue specimens. The model assists in choosing appropriate process parameters for achieving uniform temperature distribution within tissue specimen.
Osama A Hassan; Ahmed H K; Il Ences; Ahmed M El Bialy
System analysis of a negative impedance converter receiver for ultra low frequencies
Monitoring electromagnetic waves in the Ultra Low Frequency (ULF) range between 1 mHz and 1 Hz is essential for an understanding of the processes in the earths magnetosphere. Also earthquake prone areas are under suspect to emit precursor ULF signals. ... Keywords: magnetosphere, negative impedance convert, system analysis, ultra low frequency
Exact microscopic theory of electromagnetic heat transfer between a dielectric sphere and plate
Near-field electromagnetic heat transfer holds great potential for the advancement of nanotechnology. Whereas far-field electromagnetic heat transfer is constrained by Planck's blackbody limit, the increased density of states in the near-field enhances heat transfer rates by orders of magnitude relative to the conventional limit. Such enhancement opens new possibilities in numerous applications, including thermal-photo-voltaics, nano-patterning, and imaging. The advancement in this area, however, has been hampered by the lack of rigorous theoretical treatment, especially for geometries that are of direct experimental relevance. Here we introduce an efficient computational strategy, and present the first rigorous calculation of electromagnetic heat transfer in a sphere-plate geometry, the only geometry where transfer rate beyond blackbody limit has been quantitatively probed at room temperature. Our approach results in a definitive picture unifying various approximations previously used to treat this problem, and provides new physical insights for designing experiments aiming to explore enhanced thermal transfer.
Clayton Otey; Shanhui Fan
Electromagnetic form factors of hadrons
A vector meson dominance model of the electromagnetic form factors of hadrons is developed which is based on the use of unstable particle propagators. Least-square fits are made to the proton, neutron, pion and kaon form factor data in both the space and time-like regions. A good fit to the low-energy nucleon form factor data is obtained using only rho, $omega$, and phi dominance, and leads to a determination of the vector meson resonance parameters in good agreement with experiment. The nucleon-vector meson coupling constants obey simple sum rules indicating that there exists no hard core contribution to the form factors within theoretical uncertainties. The prediction for the electromagnetic radii of the proton is in reasonable agreement with recent experiments. The pion and kaon charge form factors as deduced from the nucleon form factors assuming vector meson universality are compared to the data. The pion form factor agrees with the data in both the space and time-like regions. The pion charge radius is in agreement with the recent Dubna result, but the isovector P-wave pion-pion phase shift calculated from the theory disagrees with experiment. A possible contribution to the form factors from a heavy rho meson is also evaluated. (auth)
Zidell, V.S.
Category:Ground Electromagnetic Techniques | Open Energy Information
Ground Electromagnetic Techniques Ground Electromagnetic Techniques Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Geothermalpower.jpg Looking for the Ground Electromagnetic Techniques page? For detailed information on Ground Electromagnetic Techniques, click here. Category:Ground Electromagnetic Techniques Add.png Add a new Ground Electromagnetic Techniques Technique Subcategories This category has the following 2 subcategories, out of 2 total. E [×] Electromagnetic Profiling Techniques 1 pages [+] Electromagnetic Sounding Techniques (1 categories) 2 pages Pages in category "Ground Electromagnetic Techniques" The following 2 pages are in this category, out of 2 total. E Electromagnetic Profiling Techniques Electromagnetic Sounding Techniques Retrieved from "http://en.openei.org/w/index.php?title=Category:Ground_Electromagnetic_Techniques&oldid=689834"
Electromagnetic Transients Program (EMTP) Workbook II
The complex and versatile EMTP computer program can help utilities analyze electromagnetic transients, which affect the design and operation of power systems. A workbook published in 1986 introduced basic EMTP concepts.To guide advanced users, EPRI and the EMTP Development Coordination Group cosponsored the preparation of three workbooks on complicated program applications.BackgroundStudies of electromagnetic transients were traditionally performed with special ...
Electromagnetic Transients Program (EMTP) Workbook IV
The complex and versatile EMTP computer program can help utilities analyze electromagnetic transients, which affect the design and operation of power systems. A workbook published in 1986 introduced basic EMTP concepts. To guide advanced users, EPRI and the EMTP Development Coordination Group cosponsored the preparation of three workbooks on complicated program applications.BackgroundStudies of electromagnetic transients were traditionally performed with special ...
Electromagnetic Transients Program (EMTP) Workbook III
Tunable single-photon frequency conversion in a Sagnac interferometer
We study the single-photon frequency conversion of a five-level emitter coupled to a Sagnac interferometer. We show that the unity conversion efficiency can be achieved either in resonance or off-resonance case under the ideal condition. In particular, the frequency of the output photon can be controlled by the frequencies and Rabi frequencies of the external driving fields.
Wei-Bin Yan; Jin-Feng Huang; Heng Fan
We consider the interaction between radiation, matter, and a magnetic field in a compact, relativistic jet. The entrained matter accelerates outward as the jet breaks out of a star or other confining medium. In some circumstances, such as gamma-ray bursts (GRBs), the magnetization of the jet is greatly reduced by an advected radiation field while the jet is optically thick to scattering. Where magnetic flux surfaces diverge rapidly, a strong outward Lorentz force develops and radiation and matter begin to decouple. The increase in magnetization is coupled to a rapid growth in Lorentz factor. We take two approaches to this problem. The first examines the flow outside the fast magnetosonic critical surface, and calculates the flow speed and the angular distribution of the radiation field over a range of scattering depths. The second considers the flow structure on both sides of the critical surface in the optically thin regime, using a relaxation method. In both approaches, we find how the terminal Lorentz factor and radial profile of the outflow depend on the radiation intensity and optical depth at breakout. The effect of bulk Compton scattering on the radiation spectrum is calculated by a Monte Carlo method, while neglecting the effects of internal dissipation. The peak of the scattered spectrum sits near the seed peak if radiation pressure dominates the acceleration, but is pushed to a higher frequency if the Lorentz force dominates. The unscattered seed radiation can form a distinct, low-frequency component of the spectrum, especially if the magnetic Poynting flux dominates.
Russo, Matthew [Department of Physics, University of Toronto, 60 St. George Street, Toronto, ON M5S 1A7 (Canada); Thompson, Christopher [Canadian Institute for Theoretical Astrophysics, 60 St. George Street, Toronto, ON M5S 3H8 (Canada)
On the Influence of Weak Magnetic and Electric Fields on the Fluctuations of Ionic Electric Currents in Blood Circulation
An analysis of a variety of existing experimental data leads to the conclusion on the existence of a resonance mechanism allowing weak magnetic fields to affect biological processes. These fields may either be static magnetic fields comparable in magnitude with the magnetic field of the earth or weak ultra-low frequency time-dependent fields. So far, a generally accepted theoretical model allowing one to understand the effect of magnetic and electric fields on biological processes is not available. By this reason, it is not clear which characteristics of the fields, like magnetic and electric field strength, frequency of change of the field, shape of the electromagnetic wave, the duration of the magnetic or electric influence or some particular combination of them, are responsible for the biological effect. In the present analysis it is shown that external time-independent magnetic fields may cause a resonance amplification of ionic electric currents in biological tissues and, in particular, in the vasculature system due to a Brownian motion of charges. These resonance electric currents may cause necrotic changes in the tissues or blood circulation and in this way significantly affect the biological organism. The magnitude of the magnetic fields leading to resonance effects is estimated, it is shown that it depends significantly on the radius of the blood capillaries.
Zakirjon Kanokov; Juern W. P. Schmelzer; Avazbek K. Nasirov
Electromagnetic Imaging of CO Electromagnetic Imaging of CO 2 Sequestration at an Enhanced Oil Recovery Site Barry Kirkendall (email@example.com ; 925-423-1513) Jeff Roberts (firstname.lastname@example.com ; 925-422-7108) Lawrence Livermore National Laboratory 7000 East Avenue Livermore, CA 94550 1.1 Introduction Lawrence Livermore National Laboratory (LLNL) is currently involved in a long term study using time-lapse multiple frequency electromagnetic (EM) characterization at a waterflood enhanced oil recovery (EOR) site in California operated by Chevron Heavy Oil Division in Lost Hills, California (Figure 1). The petroleum industry's interest and the successful imaging results from this project suggest that this technique be extended to monitor CO 2 sequestration at an EOR site also operated by Chevron. The impetus for this study is
Radio frequency coaxial feedthrough
An improved radio frequency coaxial transmission line vacuum feed-through provided based on the use of a half-wavelength annular dielectric pressure barrier disk, or multiple disks comprising an effective half wavelength structure to eliminate reflections from the barrier surfaces. Gas-tight seals are formed about the outer and inner diameter surfaces of the barrier disk using a sealing technique which generates radial forces sufficient to form seals by forcing the conductor walls against the surfaces of the barrier disks in a manner which does not deform the radii of the inner and outer conductors, thereby preventing enhancement of the electric field at the barrier faces which limits voltage and power handling capabilities of a feedthrough.
Owens, Thomas L. (Kingston, TN)
Electromagnetic Energy, Absorption, and Casimir Forces. I. Uniform Dielectric Media in Thermal Equilibrium
The derivation of Casimir forces between dielectrics can be simplified by ignoring absorption, calculating energy changes due to displacements of the dielectrics, and only then admitting absorption by allowing permittivities to be complex. As a first step towards a better understanding of this situation we consider in this paper the model of a dielectric as a collection of oscillators, each of which is coupled to a reservoir giving rise to damping and Langevin forces on the oscillators and a noise polarization acting as a source of a fluctuating electromagnetic (EM) field in the dielectric. The model leads naturally to expressions for the quantized EM fields that are consistent with those obtained by different approaches, and also results in a fluctuation-dissipation relation between the noise polarization and the imaginary part of the permittivity; comparison with the Rytov fluctuation-dissipation relation employed in the well-known Lifshitz theory for the van der Waals (or Casimir) force shows that the Lifshitz theory is actually a classical stochastic electrodynamical theory. The approximate classical expression for the energy density in a band of frequencies at which absorption in a dielectric is negligible is shown to be exact as a spectral thermal equilibrium expectation value in the quantum-electrodynamical theory. Our main result is the derivation of an expression for the QED energy density of a uniform dispersive, absorbing media in thermal equilibrium. The spectral density of the energy is found to have the same form with or without absorption. We also show how the fluctuation-dissipation theorem ensures a detailed balance of energy exchange between the (absorbing) medium, the reservoir and the EM field in thermal equilibrium.
F. S. S. Rosa; D. A. R. Dalvit; P. W. Milonni
Vibration Harvesting using Electromagnetic Transduction
Current Current density Torsion constant Stiffness Inductance Length conductor or length in a magnetic field Fluxcurrent density, c is the loop enclosing surface s, B is the magnetic flux density, and E is the electric field
Waterbury, Andrew
The dispersion relation and excitation of transverse magnetic mode electromagnetic waves in rippled-wall waveguide with a plasma rod and an annular dielectric
By using the linear field theory, the dispersion relation of electromagnetic waves in a rippled-wall waveguide with a plasma rod and an annular dielectric is obtained. In addition, by injecting a finite thick annular intense relativistic electron beam in this waveguide, the excitation of these waves is investigated. Furthermore, the effects of the radius of the plasma rod, the radius of the dielectric, the corrugation amplitude, and period on the frequency spectrum are investigated. Besides, the time growth rate of excitation of these waves by an annular relativistic electron beam is studied. Finally, to demonstrate the advantages of this rippled-wall waveguide, the dispersion relation and the growth rate of three simplified cases are investigated.
Nejati, M. [Physics Department, Shahid Beheshti University, G. C. Evin, Tehran (Iran, Islamic Republic of); Shokri, B. [Physics Department and Laser-Plasma Research Institute, Shahid Beheshti University, G. C. Evin, Tehran (Iran, Islamic Republic of)
Horizontal electromagnetic casting of thin metal sheets
Thin metal sheets are cast by magnetically suspending molten metal deposited within a ferromagnetic yoke and between AC conducting coils and linearly displacing the magnetically levitated liquid metal while it is being cooled to form a solid metal sheet. Magnetic flux increases as the molten metal sheet moves downward and decreases as the molten metal sheet moves upward to stabilize the sheet and maintain it in equilibrium as it is linearly displaced and solidified by cooling gases. A conducting shield is electrically coupled to the molten metal sheet by means of either metal sheet engaging rollers or brushes on the solidified metal, and by means of an electrode in the vessel containing the molten metal thereby providing a return path for the eddy currents induced in the metal sheet by the AC coil generated magnetic flux. Variation in the geometry of the conducting shield allows the magnetic flux between the metal sheet and the conducting shield to be varied and the thickness in surface quality of the metal sheet to be controlled. Side guards provide lateral containment for the molten metal sheet and stabilize and shape the magnetic field while a leader sheet having electromagnetic characteristics similar to those of the metal sheet is used to start the casting process and precedes the molten metal sheet through the magnet and forms a continuous sheet therewith. The magnet may be either U-shaped with a single racetrack coil or may be rectangular with a pair of facing bedstead coils.
Hull, John R. (Hinsdale, IL); Lari, Robert J. (Aurora, IL); Praeg, Walter F. (Palos Park, IL); Turner, Larry R. (Naperville, IL)
Visualisation of Tensor Time Domain Electromagnetic Data
Long Offset Time Domain Electromagnetic (LOTEM) measurements traditionally use a single current source. By using a second source, a tensor analysis technique analogous to that used in DC resistivity multiple-source bipole-dipole surveying, is possible. An instantaneous apparent resistivity tensor is defined as the relationship between the time varying (total) electric field and the DC half space current density vectors due to each source. If the sources are dipoles the three coordinate invariant apparent resistivities of the tensor are independent of source orientation. For a uniform half space, one of the invariants is virtually constant in time, deviating from the half space resistivity by a maximum of 6%. This method provides a way in which the complicated data set obtained during a tensor LOTEM survey can be presented in a compact and intelligible form, and has many advantages over conventional methods of analyzing LOTEM data particularly where the resistivity distribution is three dimensional (3D). Results from a 3D resistivity model of an idealized geothermal reservoir and outflow structure are used to illustrate the power of this analysis.
Caldwell, T.G.; Bibby, H.M.
An Integrated Risk Management Strategy for High-Impact, Low-Frequency (HILF) Events
Although the American electric system is one of the most reliable power systems in the world, it is vulnerable to events that rarely occur, but could have devastating impact. Collectively called high-impact, low-frequency (HILF) events, these include coordinated attacks, pandemics, severe geomagnetic disturbances (GMDs), electromagnetic pulse weapons (EMPs), and high-altitude electromagnetic pulse weapons (HEMPs). Industry has little experience in dealing with these events and lacks an integrated ...
Description, field test and data analysis of a controlled-source EM system (EM-60). [Leach Hot Springs, Grass Valley
The three sections describe the transmitter, the receiver, and data interpretations and indicate the advances made toward the development of a large moment electromagnetic (EM) system employing a magnetic dipole source. A brief description is given of the EM-60 transmitter, its general design, and the consideration involved in the selection of a practical coil size and weight for routine field operations. A programmable, multichannel, multi-frequency, phase-sensitive receiver is described. A field test of the EM-60, the data analysis and interpretation procedures, and a comparison between the survey results and the results obtained using other electrical techniques are presented. The Leach Hot Springs area in Grass Valley, Pershing County, Nevada, was chosen for the first field site at which the entire system would be tested. The field tests showed the system capable of obtaining well-defined sounding curves (amplitude and phase of magnetic fields) from 1 kHz down to 0.1 Hz. (MHR)
Morrison, H.F.; Goldstein, N.E.; Hoversten, M.; Oppliger, G.; Riveros, C.
Efficient Evaluation of Doubly Periodic Green Functions in 3D Scattering, Including Wood Anomaly Frequencies
We present efficient methods for computing wave scattering by diffraction gratings that exhibit two-dimensional periodicity in three dimensional (3D) space. Applications include scattering in acoustics, electromagnetics and elasticity. Our approach uses boundary-integral equations. The quasi-periodic Green function is a doubly infinite sum of scaled 3D free-space outgoing Helmholtz Green functions. Their source points are located at the nodes of a periodicity lattice of the grating. For efficient numerical computation of the lattice sum, we employ a smooth truncation. Super-algebraic convergence to the Green function is achieved as the truncation radius increases, except at frequency-wavenumber pairs at which a Rayleigh wave is at exactly grazing incidence to the grating. At these "Wood frequencies", the term in the Fourier series representation of the Green function that corresponds to the grazing Rayleigh wave acquires an infinite coefficient and the lattice sum blows up. At Wood frequencies, we modify the Green function by adding two types of terms to it. The first type adds weighted spatial shifts of the Green function to itself with singularities below the grating; this yields algebraic convergence. The second-type terms are quasi-periodic plane wave solutions of the Helmholtz equation. They reinstate (with controlled coefficients) the grazing modes, effectively eliminated by the terms of first type. These modes are needed in the Green function for guaranteeing the well-posedness of the boundary-integral equation that yields the scattered field. We apply this approach to acoustic scattering by a doubly periodic 2D grating near and at Wood frequencies and scattering by a doubly periodic array of scatterers away from Wood frequencies.
Oscar P. Bruno; Stephen P. Shipman; Catalin Turc; Stephanos Venakides
Intense Electromagnetic Outbursts from Collapsing Hypermassive Neutron Stars
We study the gravitational collapse of a magnetized neutron star using a novel numerical approach able to capture both the dynamics of the star and the behavior of the surrounding plasma. In this approach, a fully general relativistic magnetohydrodynamics implementation models the collapse of the star and provides appropriate boundary conditions to a force-free model which describes the stellar exterior. We validate this strategy by comparing with known results for the rotating monopole and aligned rotator solutions and then apply it to study both rotating and non-rotating stellar collapse scenarios, and contrast the behavior with what is obtained when employing the electrovacuum approximation outside the star. The non-rotating electrovacuum collapse is shown to agree qualitatively with a Newtonian model of the electromagnetic field outside a collapsing star. We illustrate and discuss a fundamental difference between the force-free and electrovacuum solutions, involving the appearance of large zones of electric-dominated field in the vacuum case. This provides a clear demonstration of how dissipative singularities appear generically in the non-linear time-evolution of force-free fluids. In both the rotating and non-rotating cases, our simulations indicate that the collapse induces a strong electromagnetic transient. In the case of sub-millisecond rotation, the magnetic field experiences strong winding and the transient carries much more energy. This result has important implications for models of gamma-ray bursts.
Luis Lehner; Carlos Palenzuela; Steven L. Liebling; Christopher Thompson; Chad Hanna
Composite materials for electromagnetic shielding
The paper shows up the research results on processing and characterization of composite materials with polymeric matrix (silicone rubber). The materials obtained in laboratory contain metallized nettling like reinforcement material and powdery graphite ... Keywords: attenuation, filling additions, frequency, plated nettling, polymeric composite on de basis of silicone rubber, shielding effectiveness
Stoian Elena Valentina; Rizescu Cristiana; Iordache Iulian; Ionita Gheorghe; Bacinschi Zorica
Investigation of an Electromagnetic Interference (EMI) Problem Involving Light-Emitting Diode Streetlights and an Amateur Radio Tran sceiver
Any type of electronic device is susceptible to energy from the electromagnetic environment. This technical update describes an investigation of electromagnetic interference (EMI) problems associated with amateur radio, distribution hardware, and streetlights at a customer's home in Camden, Tennessee. Because light-emitting diode (LED) streetlights were deemed the direct cause of the EMI problem, an investigational plan involving a two-level effort was customized to fit the situation. First, field observ...
Do you know what an electromagnet is?
Do you know what an electromagnet is? Boy did you come to the right place and ask the right question. Jefferson Lab is magnet central to the world. Several of the world's most...
An Acoustic Doppler and Electromagnetic Velocity Profiler
A freely failing current meter called the Absolute Velocity Profiler (AVP) is described. This profiler is an expansion of a previously developed instrument, the Electro-Magnetic Velocity Profiler (EMVP), with the additional capability of acoustic ...
Thomas B. Sanford; Robert G. Driver; John H. Dunlap
SP-100 thermoelectric-electromagnetic pump review
This report contains vugraphs of a presentation on thermoelectric-electromagnetic pumps. It contains: engineering drawings; summary of rectangular TEMP results and comparison with GE predictions; and results of optimization study.
Magnesium Metal Matrix Nanocomposites By Electromagnetic ...
EMAT transforms electromagnetic energy into high intensity sonication to induce ... In the current work, the physics of acoustic production, the initial conditions of ... Department of Energy's Energy Efficiency and Renewable Energy Industrial�...
Dynamic programming applied to electromagnetic satellite actuation
Electromagnetic formation flight (EMFF) is an enabling technology for a number of space mission architectures. While much work has been done for EMFF control for large separation distances, little work has been done for ...
Eslinger, Gregory John
Electrical wire insulation and electromagnetic coil
An electromagnetic coil for high temperature and high radiation application in which glass is used to insulate the electrical wire. A process for applying the insulation to the wire is disclosed which results in improved insulation properties.
Bich, George J. (Penn Hills, PA); Gupta, Tapan K. (Monroeville, PA)
Electromagnetic Pulse (EMP) and the Power Grid
This�document provides background and an introduction to the topic of electromagnetic pulse (EMP, including high-altitude EMP or HEMP) for stakeholders concerned about potential damage to power grid infrastructures.
Advances in non-planar electromagnetic prototyping
The advent of metamaterials has introduced new ways to manipulate how electromagnetic waves reflect, refract and radiate in systems where the range of available material properties now includes negative permittivity, ...
Ehrenberg, Isaac M
Electrical, electromagnetic, and magnetotelluric methods | Open Energy
Electrical, electromagnetic, and magnetotelluric methods Electrical, electromagnetic, and magnetotelluric methods Jump to: navigation, search OpenEI Reference LibraryAdd to library Journal Article: Electrical, electromagnetic, and magnetotelluric methods Abstract Application of electrical methods began with Robert W. Fox's 1830 observation of self potentials associated with copper vein deposits in Cornwall. Conrad Schlumberger introduced the direct current equal potential line resistivity method in 1912. Harry W. Conklin received the first patents on the electromagnetic (EM) method in 1917. From these beginnings, the history of the development of the resistivity induced-polarization (IP), magnetotelluric and EM methods are traced to the present time. It is of interest to note that application of electrical methods flourished from
Airborne Electromagnetic Survey | Open Energy Information
Airborne Electromagnetic Survey Airborne Electromagnetic Survey Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Technique: Airborne Electromagnetic Survey Details Activities (2) Areas (2) Regions (0) NEPA(1) Exploration Technique Information Exploration Group: Geophysical Techniques Exploration Sub Group: Electrical Techniques Parent Exploration Technique: Electromagnetic Techniques Information Provided by Technique Lithology: provide data on rock type and mineral content Stratigraphic/Structural: Hydrological: can be used to detect changes in density of fluids and indicate if there is salt water intrusion Thermal: Cost Information Low-End Estimate (USD): 48.274,827 centUSD 0.0483 kUSD 4.827e-5 MUSD 4.827e-8 TUSD / mile Median Estimate (USD): 317.3831,738 centUSD 0.317 kUSD
Electromagnetic Transient-Type Transformer Models for Geomagnetically-Induced Current (GIC) Studies
The simulation of geomagnetically-induced currents (GICs) requires adequate low-frequency transformer models. This report discusses models used for electromagnetic transient (EMT) studies in EMT-type simulation tools. Because transformers may saturate in the presence of GICs, the proper representation of transformer nonlinear behavior is important for understanding the impact of GIC on power system reliability. Other parameters, such as winding losses and core losses, will change the dc current flow ...
Whistler Wave Excitation and Effects of Self-Focusing on Ion Beam Propagation through a Background Plasma along a Solenoidal Magnetic Field
This paper extends studies of ion beam transport through a background plasma along a solenoidal magnetic field [I. Kaganovich et al., Phys. Plasmas 15, 103108 (2008)] to the important regime of moderate magnetic field strength satisfying ?ce > 2?b?pe . Here, ?ce and ? pe are the electron cyclotron frequency and electron plasma frequency, respectively, and ?b = vb/ c is the directed ion beam velocity normalized to the speed of light. The electromagnetic field perturbations excited by the ion beam pulse in this regime are calculated analytically, and verified by comparison with the numerical simulations. The degrees of beam charge neutralization and current neutralization are estimated, and the transverse component of the Lorentz force associated with the excited electromagnetic field is calculated. It is found that the plasma response to the ion beam pulse is significantly different depending on whether the value of the solenoidal magnetic field is below or above the threshold value specified by ? cr ce = 2?b?pe, and corresponding to the resonant excitation of large-amplitude whistler waves. The use of intense whistler wave excitations for diagnostic purposes is also discussed.
Mikhail A. Dorf, Igor D. Kaganovich, Edward A. Startsev, and Ronald C. Davidson
Numerical electromagnetic simulation of some systems containing charged particles with highly relativistic directed motion can by speeded up by orders of magnitude by choice of the proper Lorentz-boosted frame. A particularly good application for calculation in a boosted frame isthat of short wavelength free-electron lasers (FELs) where a high energy electron beam with small fractional energy spread interacts with a static magnetic undulator. In the optimal boost frame (i.e., the ponderomotive rest frame), the red-shifted FEL radiation and blue-shifted undulator field have identical wavelengths and the number of required longitudinal grid cells and time-steps for fully electromagnetic simulation (relative to the laboratory frame) decrease by factors of gamma^2 each. In theory, boosted frame EM codes permit direct study of FEL problems for which the eikonal approximation for propagation of the radiation field and wiggler-period-averaging for the particle-field interaction may be suspect. We have adapted the WARP code to apply this method to several electromagnetic FEL problems including spontaneous emission, strong exponential gain in a seeded, single pass amplifier configuration, and emission from e-beams in undulators with multiple harmonic components. WARP has a standard relativistic macroparticle mover and a fully 3-D electromagnetic field solver. We discuss our boosted frame results and compare with those obtained using the ?standard? eikonal FEL simulation approach.
Fawley, William; Vay, Jean-Luc
Multipole radiation in a collisonless gas coupled to electromagnetism or scalar gravitation
We consider the relativistic Vlasov-Maxwell and Vlasov-Nordstr\\"om systems which describe large particle ensembles interacting by either electromagnetic fields or a relativistic scalar gravity model. For both systems we derive a radiation formula analogous to the Einstein quadrupole formula in general relativity.
Sebastian Bauer; Markus Kunze; Gerhard Rein; Alan D. Rendall
Magnetic field adjustment structure and method for a tapered wiggler
An improved method and structure is disclosed for adjusting the magnetic field generated by a group of electromagnet poles spaced along the path of a charged particle beam to compensate for energy losses in the charged particles which comprises providing more than one winding on at least some of the electromagnet poles; connecting one respective winding on each of several consecutive adjacent electromagnet poles to a first power supply, and the other respective winding on the electromagnet pole to a different power supply in staggered order; and independently adjusting one power supply to independently vary the current in one winding on each electromagnet pole in a group whereby the magnetic field strength of each of a group of electromagnet poles may be changed in smaller increments.
Halbach, Klaus (Berkeley, CA)
Numerical Analysis of Electromagnetic Field in an Electroslag ...
Direct Numerical Simulation of Inclusion Turbulent Deposition at Liquid ... Flow and Shrinkage Pipe Formation on Macrosegregation of Investment Cast -TiAl Alloys ... Numerical Modeling of the Interaction between a Foreign Particle an�...
Occupational Electric Shocks, Electromagnetic Fields and Amyotrophic Lateral Sclerosis
A. , Fatal occupational electrocutions in the United States.Narrative Review: Electrocution and Life-ThreateningFatal occupational electrocutions in the United States. Inj
Vergara, Ximena Patricia
Work Practices Lock out/tag out procedure Safety watchers or observers Availability of protective measures Fiberglass live line
Evaluation of borehole electromagnetic and seismic detection of fractures
Experiments were conducted to establish the feasibility of downhole high-frequency techniques for location of fractures in the vicinity of boreholes. An existing flame-cut slot in granite was filled with salt water to simulate a brine-filled fracture. The first method used an electromagnetic wave at 30 to 300 MHz, vhf frequencies. A transmitter consisting of a phased dual-dipole array arranged to provide a directional signal toward the fracture was installed in a borehole opposite the fracture. A receiver was also located in the same borehole. The radar returns from the simulated fracture were detectable in boreholes located at distances of up to 12 meters from the fracture. These results indicate for the first time the feasibility of a downhole vhf radar for use in a single borehole for detection of fractures located away from the borehole. Similar experiments were also conducted using seismic waves at 4.5 to 6 KHz. The transmitter and the receiver in this case were located in separate boreholes. During this experiment, reflections from the slot were obtained only with the transducers oriented for shear wave illumination and detection. These results suggest that a high-frequency shear wave can also be used to detect fractures away from a borehole.
Chang, H.T.; Suhler, S.A.; Owen, T.E.
Recommended Rest Frequencies
Return to Table of Contents NIST Recommended Rest Frequencies for Observed Interstellar Molecular Microwave Transitions. by Frank J. Lovas. ...
Eastern Frequency Response Study
This study was specifically designed to investigate the frequency response of the Eastern Interconnection that results from large loss-of-generation events of the type targeted by the North American Electric Reliability Corp. Standard BAL-003 Frequency Response and Frequency Bias Setting (NERC 2012a), under possible future system conditions with high levels of wind generation.
Miller, N.W.; Shao, M.; Pajic, S.; D'Aquila, R.
The electromagnetic "memory" of a dc-conducting resistor: a relativity argument and the electrical circuits
A circuit-field problem is considered. A resistor conducting a constant current is argued to be associated with electromagnetic energy accumulated in the surrounded space, though contrary to the case of an inductor or a capacitor, this energy is always associated with both magnetic and electrical fields. The circuit-theory point of view saying that a resistor has no electromagnetic memory is accepted, but the necessarily involved (in view of the field argument) capacitance and inductiveness are argued then also not be associated with any memory. The mutually completing circuit and physical arguments are presented as a dialog between a physicist and an electrical engineer. How can you call "parasitic" the elements that represent the fields due to which your resistor at all receives the energy?! -- asks the physicist finally.
Emanuel Gluskin
FELIX: an experimental facility to study electromagnetic effects for first wall, blanket, and shield systems
As part of the DOE First Wall/Blanket/Shield (FW/B/S) Engineering Test Program, Argonne National Laboratory (ANL) is carrying out an experimental program to study electromagnetic effects. Electromagnetic effect in a FW/B/S system include time delay of equilibrium field penetration to the plasma, forces and torques, eddy current heating, and electrical arcing. Such effects can arise in a fusion reactor from plasma disruption and normal and abnormal charge and discharge of the magnets. The facility will consist primarily of a solenoid magnet, a surrounding pulsed dipole magnet, and associated power supplies and support structure.
Praeg, W.F.; Turner, L.R.; Biggs, J.; Bywater, J.; Fuja, R.; Knott, M.; Lari, R.J.; McGhee, D.G.; Wehrle, R.B.
Possible measurable effects of light propagating in electromagnetized vacuum, as predicted by a scalar tensor theory of gravitation
The effect of static electromagnetic fields on the propagation of light is analyzed in the context of a particular class of scalar-tensor gravitational theories. It is found that for appropriate field configurations and light polarization, anomalous amplitude variations of the light as it propagates in either a magnetized or electrified vacuum are strong enough to be detectable in relatively simple laboratory experiments.
Raptis, T E
T. E. Raptis; F. O. Minotti
Tokamak Physics EXperiment (TPX): Toroidal field magnet design, development and manufacture. SDRL 29, Analysis results. Volume 3
The electromagnetic analysis is mainly based on model built with 3-D electromagnetic software OPERA/TOSCA. In the process of evaluating the software package, some models are also built with 3-D boundary element electromagnetic software AMPERES. Fortran programs are also developed at B&W to perform Monte-Carlo simulations of the field error analysis to assist tolerance determinations.
Xu, Minfeng [Babcock and Wilcox Co., Lynchburg, VA (United States)] [Babcock and Wilcox Co., Lynchburg, VA (United States)
Electrical, electromagnetic and structural characteristics of carbon nanotube-polymer nanocomposites
Composites for Electromagnetic Interference Shielding. NanoY. Ma, et al. Electromagnetic Interference (EMI) Shieldingof Bonn). Chung DDL. Electromagnetic interference shielding
Park, Sung-Hoon
Radiative Reactions and Coherence Modeling in the High Altitude Electromagnetic Pulse
A high altitude nuclear electromagnetic pulse (EMP) with a peak field intensity of 5 x 10^4 V/m carries momentum that results in a retarding force on the average Compton electron (radiating coherently to produce the waveform) with magnitude near that of the geomagnetic force responsible for the coherent radiation. The retarding force results from a self field effect. The Compton electron interaction with the self generated magnetic field due to the other electrons accounts for the momentum density in the propagating wave; interaction with the self generated electric field accounts for the energy flux density in the propagating wave. Coherent addition of radiation is also quantitatively modeled.
Charles N. Vittitoe; Mario Rabinowitz
A numerical study was conducted to investigate the governing physics of galvanic source electromagnetic (EM) methods for terrestrial and marine exploration scenarios. The terrestrial exploration scenario involves the grounded electric dipole source EM (GESTEM) method and the examination of how the GESTEM method can resolve a thin resistive layer representing underground gas and/or hydrocarbon storage. Numerical modeling studies demonstrate that the loop transient EM (TEM) and magnetotelluric (MT) methods are insensitive to a thin horizontal resistor at depth because they utilize horizontal currents. In contrast to these standard EM methods, the GESTEM method generates both vertical and horizontal transient currents. The vertical transient current interacts with a thin horizontal resistor and causes charge buildup on its surface. These charges produce a measurable perturbation in the surface electric field at early time. The degree of perturbation depends on source waveform. When the GESTEM method is energized with step-off waveform, the perturbation due to a thin horizontal resistor is small. This is because the step-off waveform mainly consists of low frequency signals. An alternative is taking the time-derivative of the step-off responses to approximate the impulse response which includes higher frequency signals. In order to improve degree of perturbation especially due to a localized small 3-D resistor, the diffusion angle of the vertical transient current, 45 should be considered to make vertical currents coupled to a resistive target efficiently. The major drawback of the GESTEM method lies in the fact that GESTEM sounding can not be interpreted using 1-D inversion schemes if there is near-surface inhomogeneity. The marine exploration scenario investigates the physics of marine frequency-domain controlled source EM (FDCSEM) and time-domain controlled source EM (TDCSEM) methods to explore resistive hydrocarbon reservoirs in marine environments. Unlike the marine MT (MMT) method, these two methods are very sensitive to a thin hydrocarbon reservoir at depth because their sources generate vertical as well as horizontal currents. As for the FDCSEM method, the normalized EM peak response occurs where the airwave starts to dominate the seafloor EM response in the background model. This point is a function of source frequency, seawater depth and seafloor resistivity. The peak magnitude of the normalized EM response depends on whether the high concentration of vertical currents can reach and interact with the reservoir effectively. Noise levels of the EM receivers are important factors for successful FDCSEM and TDCSEM survey design. The major benefit of using magnetic field responses over electric ones is that the noise level of magnetic receiver theoretically allows for greater surface coverage compared to that of the electric receiver. Like the GESTEM method, the TDCSEM method also requires the use of a proper transient EM pulse such that the relatively high frequencies are produced. The impulse response of the TDCSEM method is characterized by two-path diffusion of the EM signal. The initial response is caused by faster signal diffusion through the less conductive seafloor, while the later arrivals result from slower diffusion through the more conductive seawater. Therefore, at larger separations, the effects of the seafloor and seawater are separable. This can be useful in reducing the airwave problem associated with the FDCSEM method in shallow marine environments.
David Alumbaugh and Evan Um
Trirotron: triode rotating beam radio frequency amplifier
High efficiency amplification of radio frequencies to very high power levels including: establishing a cylindrical cloud of electrons; establishing an electrical field surrounding and coaxial with the electron cloud to bias the electrons to remain in the cloud; establishing a rotating electrical field that surrounds and is coaxial with the steady field, the circular path of the rotating field being one wavelength long, whereby the peak of one phase of the rotating field is used to accelerate electrons in a beam through the bias field in synchronism with the peak of the rotating field so that there is a beam of electrons continuously extracted from the cloud and rotating with the peak; establishing a steady electrical field that surrounds and is coaxial with the rotating field for high-energy radial acceleration of the rotating beam of electrons; and resonating the rotating beam of electrons within a space surrounding the second field, the space being selected to have a phase velocity equal to that of the rotating field to thereby produce a high-power output at the frequency of the rotating field.
Lebacqz, Jean V. (Stanford, CA)
Electromagnetic Isotope Separation Lab (EMIS) | ORNL
Electromagnetic Isotope Separation Lab Electromagnetic Isotope Separation Lab May 30, 2013 ORNL established the Stable Isotope Enrichment Laboratory (SIEL) as part of a project funded by the DOE Office of Science, Nuclear Physics Program to develop a modernized electromagnetic isotope separator (EMIS), optimized for separation of a wide range of stable isotopes. The SIEL is located in the Building 6010 Shield Test Station, space formerly allocated to the Oak Ridge Electron Linear Accelerator, on the main campus of ORNL. ORNL staff have designed and built a nominal 10 mA ion current EMIS (sum of all isotopes at the collector) in the SIEL. This EMIS is currently being tested to determine basic performance metrics such as throughput and enrichment factor per pass. This EMIS unit and space will be used to
Spin flip probability of electron in a uniform magnetic field
The probability that an electromagnetic wave can flip the spin of an electron is calculated. It is assumed that the electron resides in a uniform magnetic field and interacts with an incoming electromagnetic pulse. The scattering matrix is constructed and the time needed to flip the spin is calculated.
Hammond, Richard T. [Department of Physics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina and Army Research Office, Research Triangle Park, North Carolina 27703 (United States)
primary frequency standards
NIST-F1 Cesium Fountain Atomic Clock The Primary Time and Frequency Standard for the United States. NIST-F1, the nation's ...
Electromagnetic Interference and the Pacemaker Patient T1-Electromagnetic Interference and the Pacemaker Patient 10/03/03
While clinically significant problems with electromagnetic interference (EMI) are rare, a pacemaker�s response to EMI becomes more diverse as technology advances. Pacemaker manufacturers continue to develop interference protection circuitry to keep up with these vast sources of EMI. The pacemaker�s response to EMI is dependent on the characteristics of the EMI, proximity to the interference, available shielding, and the sensing characteristics and polarity of the pacemaker. The pacemaker circuitry is designed to attenuate any interference outside the normal intracardiac range (10 Hz � 100 Hz). This is achieved by using bandpass filters. EMI sources can be broadly classified as galvanic, electromagnetic or magnetic. � Galvanic interference requires direct contact with electrical current. This is most often seen in defibrillation/cardioversion, cautery, TENS units and diathermy. � Electromagnetic or electrically coupled interference does not require direct body contact. This interference is most often seen with arc welders, ham radios, electrical appliances, metal detectors, therapeutic ultrasound and high voltage power lines. � Magnetic interference occurs when a patient comes in close proximity with an intense magnetic field. This is often seen in nuclear magnetic resonance imaging (NMR/MRI) and steel mill induction furnaces. EMI with signal modulation can mimic normal intracardiac signals. When detected, the response to EMI may present itself as a single beat inhibition, total inhibition, noise reversion/asynchronous pacing, rate increase, erratic pacing, or no output. These responses are usually temporary, but can be permanent if the pulse generator circuitry is damaged. A pacemaker�s response to EMI is highly dependent on the specific EMI source, the pacemaker�s mode, and sensing polarity. Included is a list that details the interaction of commonly encountered pacemaker EMI sources. Accompanying this list is a summary table of these sources and reported associated pacemaker responses.
Rev A
Estimating frequency of change
Many online data sources are updated autonomously and independently. In this article, we make the case for estimating the change frequency of data to improve Web crawlers, Web caches and to help data mining. We first identify various scenarios, where ... Keywords: Change frequency estimation, Poisson process
Junghoo Cho; Hector Garcia-Molina
Stabilized radio frequency quadrupole
Disclosed is a long-vane stabilized radio frequency resonator for accelerating charged particles and including means defining a radio frequency resonator cavity, a plurality of long vanes mounted in the defining means for dividing the cavity into sections, and means interconnecting opposing ones of the plurality of vanes for stabilizing the resonator. 5 figs.
Lancaster, H.D.; Fugitt, J.A.; Howard, D.R.
Electromagnetic confinement and movement of thin sheets of molten metal
An apparatus capable of producing a combination of magnetic fields that can retain a metal in liquid form in a region having a smooth vertical boundary including a levitation magnet that produces low frequency magnetic field traveling waves to retain the metal and a stabilization magnet that produces a high frequency magnetic field to produce a smooth vertical boundary. As particularly adapted to the casting of solid metal sheets, a metal in liquid form can be continuously fed into one end of the confinement region produced by the levitation and stabilization magnets and removed in solid form from the other end of confinement region. An additional magnet may be included for support at the edges of the confinement region where eddy currents loop.
Lari, Robert J. (Aurora, IL); Praeg, Walter F. (Palos Park, IL); Turner, Larry R. (Naperville, IL)
Build A Stronger Electromagnet Project Overview
this activity? 5. How did various sub-populations of students perform? Consider factors such as gender, race Electromagnet Sunshine State Standards Middle School: · The student recognizes that energy may be changed: · The student recognizes that energy may be changed in form with varying efficiency. (SC.B.1.4) · The student
Weston, Ken
Electromagnetic Wellbore Heating Ibrahim Agyemang1
. temperature from the heat sources in any EMIT regions. Parts i) and ii) result in a second order ODE is inversely proportional to the velocity. Fluid that moves slowly past an EMIT region will absorb more heatChapter 5 Electromagnetic Wellbore Heating Ibrahim Agyemang1 , Matthew Bolton2 , Lloyd Bridge2
Bohun, C. Sean
Electromagnetic Composites at the Compton Scale
A new class of electromagnetic composite particles is proposed. The composites are very small (the Compton scale), potentially long-lived, would have unique interactions with atomic and nuclear systems, and, if they exist, could explain a number of otherwise anomalous and conflicting observations in diverse research areas.
Frederick J. Mayer; John R. Reitz
Televisions, video privacy, and powerline electromagnetic interference
We conduct an extensive study of information leakage over the powerline infrastructure from eight televisions (TVs) spanning multiple makes, models, and underlying technologies. In addition to being of scientific interest, our findings contribute to ... Keywords: electromagnetic interference, information leakage, powerline security
Miro Enev; Sidhant Gupta; Tadayoshi Kohno; Shwetak N. Patel
Problems in electromagnetic mass-difference calculations
A brief discussion is given on the progress made thus far in calculating the electromagnetic mass differences of elementary particles. Some of the methods discussed include Feynman's method, Cottinghams method, the methods involving Bjorken scaling iunctions, and the formalism of Dashen and Frautschi. (LBS)
Majumdar, D.P.
Information Leakage via Electromagnetic Emanation and Effectiveness of Averaging Technique
It is well known that there is relationship between electromagnetic emanation and processing information in IT devices such as personal computers and smart cards. In this paper, we show how to estimate amount of information that is leaked as electromagnetic ... Keywords: Tempest, Channel capacity, electromagnetic emanation, averaging technique
Hidema Tanaka
Measurements of current sheet canting in a pulsed electromagnetic accelerator
Measurements of current sheet canting in a pulsed electromagnetic accelerator T. E. Markusic, E. Y canting in pulsed electromagnetic accelerators is the departure of the plasma sheet (that carries in an experimental pulsed electromagnetic accelerator, using a variety of propellants and pressure levels
Electromagnetic compatibility, tropospheric and ionospheric aspects of SPS MPTS operations
The results of a preliminary study of the effects of operation of a Solar Power Satellite (SPS) on the general performance of terrestrial and space based electromagnetic systems are given. In addition, the effects of a passing high energy Microwave Power Transmission System (MPTS) through the troposphere and through the ionosphere are also considered. The SPS as envisioned will be a satellite system in geosynchronous orbit with a solar array of about 144 square kilometers. The purpose of the SPS is to capture solar energy, convert the radiant energy to microwave energy and transmit it to the earth as a beam by means of a phased array antenna one kilometer in diameter at a frequency of 2.45 GHz. At the surface of the earth, the energy beam will be captured by an antenna about 100 square kilometers which will convert the microwave energy to high voltage ac power for injection into an electrical power network. The impact of SPS operation on the lower atmosphere, the ionosphere, and on operational telecommunication systems, is addressed in a preliminary manner. Topics include (a) further study on the susceptibility of electronic equipment to SPS emissions; (b) further study on the interference potential of SPS emissions and harmonics to electromagnetic systems; (c) study of the impact of tropospheric attenuation and scattering associated with SPS operation on microwave terrestrial, air/ground and satellite/ground telecommunication systems; (d) further theoretical study on the production of ionospheric irregularities resulting from microwave heating; and (e) further experimental evidence of the impact of SPS operation on the telecommunication system performance collected in conjunction with a Platteville microwave heating experiment.
Not Available
Incompatibility of the tunneling limit with laser fields
The Schwinger limit refers to longitudinal electric fields that are sufficiently strong to "polarize the vacuum" into electron-positron pairs by a tunneling mechanism. Laser fields are transverse electromagnetic fields for which the Schwinger limit has no relevance. Longitudinal and transverse fields are fundamentally different because of the different values of the F^{{\\mu}{\
H. R. Reiss
Monitoring of thermal enhanced oil recovery processes with electromagnetic methods
Research in applying electromagnetic methods for imaging thermal enhanced oil recovery has progressed significantly during the past eighteen months. Working together with researchers at Lawrence Berkeley Laboratory (LBL) and supported by a group of industrial sponsors we have focused our effort on field system development and doing field surveys connected with EOR operations. Field surveys were recently completed at the Lost Hills No.3 oil field and at UC Richmond Field station. At Lost Hills, crosshole EM data sets were collected before a new phase of steam injection for EOR and again four months after the onset of steaming. The two data sets were nearly identical suggesting that very little steam had been injected into this borehole. This is in accord with the operators records which indicate injectivity problems with this particular well. At Richmond we conducted a salt water injection monitoring experiment where 50,000 gallons of salt water were injected in a shallow aquifer and crosshole EM data were collected using the injection well and several observation wells. We applied the imaging code to some of the collected data and produced an image showing that the salt water slug has propagated 8--10 m from the injector into the aquifer. This result is partially confirmed by prior calculations and well logging data. Applying the EM methods to the problem of oil field characterization essentially means extending the borehole resistivity log into the region between wells. Since the resistivity of a sedimentary environment is often directly dependent on the fluids in the rock the knowledge of the resistivity distribution within an oil field can be invaluable for finding missed or bypassed oil or for mapping the overall structure. With small modification the same methods used for mapping EOR process can be readily applied to determining the insitu resistivity structure.
Wilt, M.
A New Look on the Electromagnetic Duality. Suggestions and Developments
In this paper a new look on the electro-magnetic duality is presented and appropriately exploited. The duality analysis in the nonrelativistic and relativistic formulations is shown to lead to the idea the mathematical model field to be a differential form valued in the 2-dimensional vector space ${\\cal R}^2$. A full ${\\cal R}^2$ covariance is achieved through introducing explicitly the canonical complex structure ${\\cal I}$ of ${\\cal R}^2$ in the nonrelativistic equations. The connection of the relativistic Hodge * with ${\\cal I}$ is shown and a complete coordinate free relativistic form of the equations and the conservative quantities is obtained. The duality symmetry is interpreted as invariance of the conservative quantities and conservation equations.
Donev, S
Stoil Donev
Electromagnetic valve for controlling the flow of molten, magnetic material
An electromagnetic valve for controlling the flow of molten, magnetic material is provided, which comprises an induction coil for generating a magnetic field in response to an applied alternating electrical current, a housing, and a refractory composite nozzle. The nozzle is comprised of an inner sleeve composed of an erosion resistant refractory material (e.g., a zirconia ceramic) through which molten, magnetic metal flows, a refractory outer shell, and an intermediate compressible refractory material, e.g., unset, high alumina, thermosetting mortar. The compressible refractory material is sandwiched between the inner sleeve and outer shell, and absorbs differential expansion stresses that develop within the nozzle due to extreme thermal gradients. The sandwiched layer of compressible refractory material prevents destructive cracks from developing in the refractory outer shell. 5 figs.
Richter, T.
Relativistic electromagnetic flat top solitons and their stability
The inclusion of ion response in the study of relativistically intense electromagnetic laser pulse propagation in plasma yields certain distinct varieties of single peak solitonic structures. A flat top slow moving structure (for which the various fields have a flat profile over a wide spatial range) is one such solution. A detailed characterization of these solutions along with the eigen spectrum of their formation in the parameter space has been presented. The evolution of this particular solution is studied in detail with the help of a coupled fluid Maxwell set of equations. The study shows that the flat top solution is unstable. The instability is characterized as the backward Brillouin instability for which the electron quiver velocity plays the role of the effective temperature.
Sundar, Sita; Das, Amita; Saxena, Vikrant; Kaw, Predhiman; Sen, Abhijit [Institute for Plasma Research, Bhat, Gandhinagar-382428 (India)
An electromagnetic valve for controlling the flow of molten, magnetic material is provided, which comprises an induction coil for generating a magnetic field in response to an applied alternating electrical current, a housing, and a refractory composite nozzle. The nozzle is comprised of an inner sleeve composed of an erosion resistant refractory material (e.g., a zirconia ceramic) through which molten, magnetic metal flows, a refractory outer shell, and an intermediate compressible refractory material, e.g., unset, high alumina, thermosetting mortar. The compressible refractory material is sandwiched between the inner sleeve and outer shell, and absorbs differential expansion stresses that develop within the nozzle due to extreme thermal gradients. The sandwiched layer of compressible refractory material prevents destructive cracks from developing in the refractory outer shell.
Richter, Tomas (State College, PA)
A quantum top in a Casimir-induced quadrupole field
The Casimir energy is the change in energy of a configuration of objects due to second quantization of the electromagnetic field. The Casimir energy of a dielectric object inside a perfectly conducting sphere was recently ...
Fitzgerald, Eric Andrew Vitus
Prototype Engineered Barrier System Field Test (PEBSFT); Final report
This final report represents a summary of data and interpretations obtained from the Prototype Engineered Barrier System Field Test (PEBSFT) performed in G-Tunnel within the Nevada Test Site. The PEBSFT was conducted to evaluate the applicability of measurement techniques, numerical models, and procedures developed for future field tests that will be conducted in the Exploratory Studies Facilities (ESF) at Yucca Mountain. The primary objective of the test was to provide a basis for determining whether tests planned for the ESF have the potential to be successful. Chapter 1 on high frequency electromagnetic tomography discusses the rock mass electromagnetic permittivity and attenuation rate changes that were measured to characterize the water distribution in the near field of a simulated waste container. The data are used to obtain quantitative estimates of how the moisture content in the rock mass changes during heating and to infer properties of the spatial variability of water distribution, leading to conclusions about the role of fractures in the system. Chapter 2 discusses the changes in rock moisture content detected by the neutron logging probe. Chapter 3 permeability tests discusses the characterization of the in-situ permeability of the fractured tuff around the borehole. The air permeability testing apparatus, the testing procedures, and the data analysis are presented. Chapter 4 describes the moisture collection system installed in the heater borehole to trap and measure the moisture volumes. Chapter 5 describes relative humidity measurements made with the thermocouple psychrometer and capacitance sensors. Chapter 6 discusses gas pressure measurements in the G-Tunnel, addressing the calibration and installation of piezoresistive-gaged transducers. Chapter 7 describes the calibration and installation of thermocouples for temperature measurements. Chapter 8 discusses the results of the PEBSFT.
Ramirez, A.L. [ed.; Buscheck, T.; Carlson, R.; Daily, W.; Lee, K.; Lin, Wunan; Mao, Nai-hsien; Ueng, Tzou-Shin; Wang, H.; Watwood, D.
Low-frequency RF Coupling To Unconventional (Fat Unbalanced) Dipoles
The report explains radio frequency (RF) coupling to unconventional dipole antennas. Normal dipoles have thin equal length arms that operate at maximum efficiency around resonance frequencies. In some applications like high-explosive (HE) safety analysis, structures similar to dipoles with ''fat'' unequal length arms must be evaluated for indirect-lightning effects. An example is shown where a metal drum-shaped container with HE forms one arm and the detonator cable acts as the other. Even if the HE is in a facility converted into a ''Faraday cage'', a lightning strike to the facility could still produce electric fields inside. The detonator cable concentrates the electric field and carries the energy into the detonator, potentially creating a hazard. This electromagnetic (EM) field coupling of lightning energy is the indirect effect of a lightning strike. In practice, ''Faraday cages'' are formed by the rebar of the concrete facilities. The individual rebar rods in the roof, walls and floor are normally electrically connected because of the construction technique of using metal wire to tie the pieces together. There are two additional requirements for a good cage. (1) The roof-wall joint and the wall-floor joint must be electrically attached. (2) All metallic penetrations into the facility must also be electrically connected to the rebar. In this report, it is assumed that these conditions have been met, and there is no arcing in the facility structure. Many types of detonators have metal ''cups'' that contain the explosives and thin electrical initiating wires, called bridge wires mounted between two pins. The pins are connected to the detonator cable. The area of concern is between the pins supporting the bridge wire and the metal cup forming the outside of the detonator. Detonator cables usually have two wires, and in this example, both wires generated the same voltage at the detonator bridge wire. This is called the common-mode voltage. The explosive component inside a detonator is relatively sensitive, and any electrical arc is a concern. In a safety analysis, the pin-to-cup voltage, i.e., detonator voltage, must be calculated to decide if an arc will form. If the electric field is known, the voltage between any two points is simply the integral of the field along a line between the points. Eq. 1.1. For simplicity, it is assumed that the electric field and dipole elements are aligned. Calculating the induced detonator voltage is more complex because of the field concentration caused by metal components. If the detonator cup is not electrically connected to the metal HE container, the portion of the voltage generated by the dipole at the detonator will divide between the container-to-cup and cup-to-pin gaps. The gap voltages are determined by their capacitances. As a simplification, it will be assumed the cup is electrically attached, short circuited, to the HE container. The electrical field in the pin-to-cup area is determined by the field near the dipole, the length of the dipole, the shape of the arms, and the orientation of the arms. Given the characteristics of a lightning strike and the inductance of the facility, the electric fields in the ''Faraday cage'' can be calculated. The important parameters for determining the voltage in an empty facility are the inductance of the rebars and the rate of change of the current, Eq. 1.3. The internal electric fields are directly related to the facility voltages, however, the electric fields in the pin-to-cup space is much higher than the facility fields because the antenna will concentrate the fields covered by the arms. Because the lightning current rise-time is different for every strike, the maximum electric field and the induced detonator voltage should be described by probability distributions. For pedantic purposes, the peak field in the simulations will be simply set to 1 V/m. Lightning induced detonator voltages can be calculated by scaling up with the facility fields. Any metal object around the explosives, such as a work stand, will also distort the electric
Ong, M M; Brown, C G; Perkins, M P; Speer, R D; Javedani, J B
Mode Conversion of Langmuir to Electromagnetic Waves with Parallel Inhomogeneity in the Solar Wind and the Corona
Linear mode conversion of Langmuir waves to radiation near the plasma frequency at density gradients is potentially relevant to multiple solar radio emissions, ionospheric radar experiments, laboratory plasma devices, and pulsars. Here we study mode conversion in warm magnetized plasmas using a numerical electron fluid simulation code with the density gradient parallel to the ambient magnetic field B0 for a range of incident Langmuir wavevectors. Our results include: (1) Both o- and x-mode waves are produced for ? ? (?L)1/3(?c/?) somewhat less than 1, contrary to previous ideas. Only o mode is produced for ? and somewhat greater than 1.5. Here ?c is the (angular) electron cyclotron frequency, ? the angular wave frequency, and L the length scale of the (linear) density gradient. (2) In the unmagnetized limit, equal amounts of o- and x-mode radiation are produced. (3) The mode conversion window narrows as ? increases. (4) As ? increases the total electromagnetic field changes from linear to circular polarization, with the o- and x- mode signals remaining circularly polarized. (5) The conversion efficiency to the x mode decreases monotonically as ? increases while the o-mode conversion efficiency oscillates due to an interference phenomenon between incoming and reflected Langmuir/z modes. (6) The total conversion efficiency for wave energy from the Langmuir/z mode to radiation is typically less than 10%, but the corresponding power efficiencies differ by the ratio of the group speeds for each mode and are of order 50 ? 70%. (7) The interference effect and the disappearance of the x mode at ? somewhat greater than 1 can be accounted for semiquantitatively using a WKB-like analysis. (8) Constraints on density turbulence are developed for the x mode to be generated and be able to propagate from the source. (9) Standard parameters for the corona and the solar wind near 1 AU suggest that linear mode conversion should produce both o- and x- mode radiation for solar and interplanetary radio bursts. It is therefore possible that linear mode conversion under these conditions might explain the weak total circular polarizations of type II and III solar radio bursts.
Eun-Hwa Kim, Iver H. Cairns, and Peter A. Robinson
Assessment of Partial Discharge and Electromagnetic Interference On-Line Testing of Turbine-Driven Generator Stator Winding Insulati on Systems
Partial discharge (PD) and electromagnetic interference (EMI) on-line testing have been promoted as means to assess the condition of turbine-driven generator stator winding insulation systems. Such test approaches offer clear advantages in avoiding prolonged generator shutdown for off-line tests and inspections. Although PD is a time-domain measurement and EMI measures activity with a frequency scan, both techniques still evaluate the same phenomenon -- high-frequency currents that flow as a result of el...
Electromagnetic Duality and New Solutions of the Non-minimally Coupled Y(R)-Maxwell Gravity
Non-minimally coupled Y(R)-Maxwell gravity which have some interesting solutions may be used to understand dark matter, dark energy, the origin of cosmic magnetic field and the evaluation of the universe. We give some new solutions to the model such as spherically symmetric electric, magnetic and dyon solutions. We point out an existence of an electromagnetic duality transformation for the model.
�zcan Sert
The main problems arising during the design and con struction of medium size air-core electro-magnets are discussed. The basic equations are given relating magnetic field strength, magnetic field rise time, power input, electrodynamic forces, and thermal conditions e.g., allowable temperature rise to give the detailed dimensions required for the electrical conductor and the cooling annull. The details for a 25 kgauss sectional oil-cooled electromagnet for plasma research are described. (auth)
Gryzinski, M.; Sadowski, M.
Electromagnetic radiation absorbers and modulators comprising polyaniline
A composition for absorbing electromagnetic radiation, wherein said electromagnetic radiation possesses a wavelength generally in the range of from about 1000 Angstroms to about 50 meters, wherein said composition comprises a polyaniline composition of the formula ##STR1## where y can be equal to or greater than zero, and R.sup.1 and R.sup.2 are independently selected from the group containing of H, --OCH.sub.3, --CH.sub.3, --F, --Cl, --Br, --I, NR.sup.3 .sub.2, --NHCOR.sup.3, --OH, --O.sup.-, SR.sup.3, --OCOR.sup.3, --NO.sub.2, --COOH, --COOR.sup.3, --COR.sup.3, --CHO, and --CN, where R.sup.3 is a C.sub.1 to C.sub.8 alkyl, aryl or aralkyl group.
Epstein, Arthur J. (Bexley, OH); Ginder, John M. (Columbus, OH); Roe, Mitchell G. (Columbus, OH); Hajiseyedjavadi, Hamid (Columbus, OH)
Efficient imaging of single-hole electromagnetic data
The extended Born, or localized nonlinear (LN) approximation, of integral equation (IE) solution has been applied to inverting single-hole electromagnetic (EM) data using a cylindrically symmetric model. The extended Born approximation is less accurate than a full solution but much superior to the simple Born approximation. When applied to the cylindrically symmetric model with a vertical magnetic dipole source, however, the accuracy of the extended Born approximation is shown to be greatly improved because the electric field is scalar and continuous everywhere. One of the most important steps in the inversion is the selection of a proper regularization parameter for stability. The extended Born solution provides an efficient means for selecting an optimum regularization parameter, because the Green's functions, the most time consuming part in IE methods, are repeatedly re-usable at each iteration. In addition, the IE formulation readily contains a sensitivity matrix, which can be revised at each iteration at little expense. In this paper we show inversion results using synthetic and field data. The result from field data is compared with that of a 3-D inversion scheme.
Lee, Ki Ha; Kim, Hee Joon; Wilt, Mike
Electromagnetic Interference Emission Measurements Near FACTS Devices
The expanded application of flexible AC transmission system (FACTS) technology to electric transmission and distribution systems frequently provides the best means of ensuring the needed levels of capacity and reliability. This final report provides a detailed look at the electromagnetic emissions from three tested FACTS systems. The report provides equipment immunity requirements from several potentially applicable standards, along with immunity data for nationwide differential global positioning system...
The expanded application of flexible AC transmission system (FACTS) technology to the electric transmission and distribution systems frequently provides the best means of insuring the needed levels of capacity and reliability. This interim report provides a detailed look at the electromagnetic emissions from the first two FACTS systems tested. Equipment immunity requirements from several potentially applicable standards are provided along with immunity data for nationwide differential global positioning ...
Electromagnetic Modelling of Superconducting Sensor Designs
DEPARTMENT OF MATERIALS SCIENCE AND METALLURGY Electromagnetic Modelling of Superconducting Sensor Designs Guido Gerra Clare Hall, University of Cambridge 1 Preface The present dissertation has been submitted... and for all the moments they have shared with me. 4 Abstract The problem of design optimisation of thin film direct current Superconducting QUantum Interference Device (SQUID) magnetometers made of YBCO (YBa2Cu3O7-x) was considered. The inductances...
Gerra, Guido
Electromagnetic Casimir Forces in Elliptic Cylinder Geometries
The scattering theory approach makes it possible to carry out exact calculations of Casimir energies in any geometry for which the scattering T-matrix and a partial wave expansion of the free Green's function are available. We implement this program for the case of a perfectly conducting elliptic cylinder, thereby completing the set of geometries where electromagnetic scattering is separable. Particular emphasis is placed on the case of zero radius, where the elliptic cylinder reduces to a strip.
Noah Graham
Power System and Railroad Electromagnetic Compatibility Handbook
This book is a source of technology and data for preventing and mitigating ac electrical interference problems on railroads. All aspects of electromagnetic compatibility (EMC) where railroad systems are the receptors are examined. This includes well-understood areas such as magnetic induction from transmission lines as well as less understood areas such as conducted interference from distribution systems and effects of harmonics. Chapters examine all known effects of ac interference, including personnel ...
Efficient Continuous-Duty Bitter-Type Electromagnets for Cold Atom Experiments
We present the design, construction and characterization of Bitter-type electromagnets which can generate high magnetic fields under continuous operation with efficient heat removal for cold atom experiments. The electromagnets are constructed from a stack of alternating layers consisting of copper arcs and insulating polyester spacers. Efficient cooling of the copper is achieved via parallel rectangular water cooling channels between copper layers with low resistance to flow; a high ratio of the water-cooled surface area to the volume of copper ensures a short length scale ~1 mm to extract dissipated heat. High copper fraction per layer ensures high magnetic field generated per unit energy dissipated. The ensemble is highly scalable and compressed to create a watertight seal without epoxy. From our measurements, a peak field of 770 G is generated 14 mm away from a single electromagnet with a current of 400 A and a total power dissipation of 1.6 kW. With cooling water flowing at 3.8 l/min, the coil temperatur...
Sabulsky, Dylan; Gemelke, Nathan D; Chin, Cheng
Status Update for the Evaluation of Electromagnetic Nondestructive Evaluation System for Detecting and Quantifying Graphitization in High-Energy Piping
The project team performed several studies to evaluate the balanced field electromagnetic technique (BFET) for detection, and possibly classification, of graphitization in carbon-molybdenum tubing and piping. Samples of boiler tubes and high-energy pipes suspected to contain graphitization were procured from five power plants in the United ...
BEP project for Applied Mathematics/Applied Physics double degree Numerical solution of a three-dimensional electromagnetic
-dimensional electromagnetic force field Imagine a quadratic piece of metal, which is subject to a static current flux at its top boundary and insulated at the bottom. Assuming the current flux to be of Gaussian shape and applying suitable boundary conditions, we can derive equations to describe the current flux in the metal
Vuik, Kees
U.S ITER : electromagnetic analysis of transient forces due to disrupted plasma currents on the ITER shield modules.
This paper describes the electromagnetic analysis that has been completed using the OPERA-3d product to characterize the forces on the ITER shield modules as part of the conceptual design. These forces exist due to the interaction of the eddy currents induced in the shield modules and the large magnetic fields present in the tokamak.
Kotulski, Joseph Daniel; Coats, Rebecca Sue; Pasik, Michael Francis
An obliquely propagating electromagnetic drift instability in the lower hybrid frequency range
and laboratory plasma research [see, e.g., Gary, 1993]. Recently, this topic has been revisited in the context
Ji, Hantao
Influence of field potential on the speed of light
The paper discusses the affection of the scalar potential on the speed of light in the electromagnetic field, by means of the characteristics of octonion. In the octonion space, the radius vector is combined with the integral of field potentials to become one new radius vector. When the field potentials can not be neglected, the new radius vector will cause the prediction to departure slightly from the theoretical value of the speed of light. The results explain why the speed of light varies in diversiform optical waveguide. And there exist negative refractive indexes due to different scalar potentials in the gravitational field and electromagnetic field.
Zi-Hua Weng
High-order optical harmonic generation as a process of single atom interaction with sub-relativistic single- and multicolor laser fields
We present a non-perturbative theory of a single atom interaction with the multicolor laser field. The theory is based on the use of exact mathematical solutions of the boundary value problem for 'an atom in the external field', as a result the case of arbitrary orientation of atomic angular momentum and electromagnetic wave polarization vector can be described in the consistent mathematical form. We also present the results of numerical simulations on silver and argon atoms interaction with single-and two-color laser fields formed by fundamental frequency and second harmonic of Ti:Sapphire laser. The results of numerical calculations show that the efficiency of high-order harmonic generation (HHG) depends strongly on the laser field parameters (especially on the orientation of polarization vectors and chirp of the two-color laser field components). We have demonstrated the saturation of the cut-off frequency in the laser fields of near-atomic strength and investigated the impact of the field phase in the case of ultrashort laser pulses.
Andreev, A. V.; Stremoukhov, S. Yu.; Shoutova, O. A. [M. V. Lomonosov Moscow State University, physical department, 119991 Leninskie Gory, 1, build. 2, Moscow (Russian Federation)
High-frequency plasma-heating apparatus
An array of adjacent wave guides feed high-frequency energy into a vacuum chamber in which a toroidal plasma is confined by a magnetic field, the wave guide array being located between two toroidal current windings. Waves are excited in the wave guide at a frequency substantially equal to the lower frequency hybrid wave of the plasma and a substantially equal phase shift is provided from one guide to the next between the waves therein. For plasmas of low peripheral density gradient, the guides are excited in the TE.sub.01 mode and the output electric field is parallel to the direction of the toroidal magnetic field. For exciting waves in plasmas of high peripheral density gradient, the guides are excited in the TM.sub.01 mode and the magnetic field at the wave guide outlets is parallel to the direction of the toroidal magnetic field. The wave excited at the outlet of the wave guide array is a progressive wave propagating in the direction opposite to that of the toroidal current and is, therefore, not absorbed by so-called "runaway" electrons.
Brambilla, Marco (St. Egreve, FR); Lallia, Pascal (Grenoble, FR)
Guided wave methods and apparatus for nonlinear frequency generation
Methods and apparatus are disclosed for the nonlinear generation of sum and difference frequencies of electromagnetic radiation propagating in a nonlinear material. A waveguide having a waveguide cavity contains the nonlinear material. Phase matching of the nonlinear generation is obtained by adjusting a waveguide propagation constant, the refractive index of the nonlinear material, or the waveguide mode in which the radiation propagates. Phase matching can be achieved even in isotropic nonlinear materials. A short-wavelength radiation source uses phase-matched nonlinear generation in a waveguide to produce high harmonics of a pulsed laser.
Durfee, III, Charles G. (Ann Arbor, MI); Rundquist, Andrew (Austin, TX); Kapteyn, Henry C. (Ann Arbor, MI); Murnane, Margaret M. (Ann Arbor, MI)
A fields only version of the Lorentz Force Law: Particles replaced by their fields
We show that the Lorentz force law, F^L_1=q_1(E+v_1xB) being the charge on particle 1 interacting with the electromagnetic fields due to all other particles, can be written in a pure field form F^L_1=-\
Philip H. Butler; Niels G. Gresnigt; Martin B. van der Mark; Peter F. Renaud
Electromagnetic gearing applications in hybrid-electric vehicles
In this thesis, the operation of electric machines as three port devices is studied in detail. Electric machines used in this manner are referred to as electromagnetic gears in this research. All possible steady-state operating modes of these three-port devices have been explained in this thesis. Mathematical models for operating a switched reluctance machine and a separately excited dc machine as electromagnetic gears have been derived. These models have been used for simulating the performance of electromagnetic gears under various operating conditions. Electromagnetic gears can be used in hybrid electric propulsion systems as power sharing devices. This thesis explains the detailed operation of a new hybrid propulsion system utilizing electromagnetic gears. This propulsion system was proposed by Dr. M. Ehsani and has been named the "Transmotor Hybrid". The limitation of this propulsion system has also been explained in this thesis. The application of electromagnetic gears in hybrid propulsion systems has been described in detail in this research.
Sodhi, Sameer
Why inverse document frequency?
Inverse Document Frequency (IDF) is a popular measure of a word's importance. The IDF invariably appears in a host of heuristic measures used in information retrieval. However, so far the IDF has itself been a heuristic. In this paper, we show IDF to ...
Kishore Papineni
A radio frequency coaxial feedthrough
An improved radio frequency coaxial transmission line vacuum feedthrough is provided based on the use of a half-wavelength annular dielectric pressure barrier disk, or multiple disks comprising an effective half wavelength structure to eliminate reflection from the barrier surfaces. Gas-tight seals are formed about the outer and inner diameter surfaces of the barrier disk using a sealing technique which generates radial forces sufficient to form seals by forcing the conductor walls against the surfaces of the barrier disks in a manner which does not deform the radii of the inner and outer conductors, thereby preventing enhancement of the electric field at the barrier faces which limits the voltage and power handling capabilities of a feedthrough.
Owens, T.L.
A Closed Algebra of Clebsch Forms Derived from Whittaker Super-potentials and applications in electromagnetic research
A type of closed exterior algebra in R3 under the cross product is revealed to hold between differential forms from the three Whittaker scalar potentials, associated with the fields of a moving electron. A special algebraic structure is revealed in the context of Clebsch reparametrization of these scalars, and a special prescription for the construction of permutation invariant electromagnetic fields is given as well as a superposition with parallel electric and magnetic components.
Recommended electromagnetic operating envelopes for safety-related I and C systems in nuclear power plants: Draft report for comment
This document presents recommendations for electromagnetic operating envelopes to augment test criteria and test methods addressing electromagnetic interference (EMI), radio-frequency interference (RFI), and power surges that are applicable to safety-related instrumentation and control (I and C) systems in nuclear power plants. The Oak Ridge National Laboratory (ORNL) was engaged by the US Nuclear Regulatory Commission (NRC) Office of Nuclear Regulatory Research to assist in developing the technical basis for regulatory guidance on EMI/RFI immunity and power surge withstand capability (SWC). Previous research has provided recommendations on electromagnetic compatibility (EMC) design and installation practices, endorsement of EMI/RFI immunity and SWC test criteria and test methods, and determination of ambient electromagnetic conditions at nuclear power plants. The present research involves development of recommended electromagnetic envelopes that are applicable to nuclear power plant locations where safety-related I and C systems either are or may be installed. These recommended envelopes establish both emissions criteria and the levels of radiated and conducted interference that I and C systems should be able to withstand without upset or malfunction. The EMI/RFI operating envelopes are derived from conditions in comparable military environments and are confirmed by comparison with the nuclear power plant electromagnetic environment based on measured plant emissions profiles. Detailed information on specific power surge conditions in nuclear power plants is not available, so industrial guidance on representative surge characteristics for susceptibility testing is adopted. An engineering assessment of the power surge environment in nuclear power plants leads to the recommendation of operating envelopes based on location categories and exposure levels defined in IEEE Std C62.41-1991, IEEE Recommended Practice on Surge Voltages in Low-Voltage AC Power Circuits.
Ewing, P.D.; Wood, R.T. [Oak Ridge National Lab., TN (United States)
Polarization and spatial coherence of electromagnetic waves in uncorrelated disordered media
Spatial field correlation functions represent a key quantity for the description of mesoscopic phenomena in disordered media and the optical characterization of complex materials. Yet many aspects related to the vector nature of light waves have not been investigated so far. We study theoretically the polarization and coherence properties of electromagnetic waves produced by a dipole source in a three-dimensional uncorrelated disordered medium. The spatial field correlation matrix is calculated analytically using a multiple scattering theory for polarized light. This allows us to provide a formal description of the light depolarization process in terms of "polarization eigenchannels" and to derive analytical formulas for the spatial coherence of multiply-scattered light.
Vynck, Kevin; Carminati, R�mi
Quadratic helicities and the energy of magnetic fields
Two non-local asymptotic invariants of magnetic fields for the ideal magnetohydrodynamics are introduced. The velocity of variation of the invariants for a non-ideal magnetohydrodynamics with a small magnetic dissipation is estimated. By means of the invariants the spectra of electromagnetic fields are investigated. A possible role of higher magnetic helicities during a relaxation of magnetic fields is discussed.
Petr M. Akhmet'ev
Akhmet'ev, Petr M
Electromagnetic effects of neutrinos in an electron gas
We study the electromagnetic properties of a system that consists of an electron background and a neutrino gas that may be moving or at rest, as a whole, relative to the background. The photon self-energy for this system is characterized by the usual transverse and longitudinal polarization functions, and two additional ones which are the focus of our calculations, that give rise to birefringence and anisotropic effects in the photon dispersion relations. Expressions for them are obtained, which depend on the neutrino number densities and involve momentum integrals over the electron distribution functions, and are valid for any value of the photon momentum and general conditions of the electron gas. Those expressions are evaluated explicitly for several special cases and approximations which are generally useful in astrophysical and cosmological settings. Besides studying the photon dispersion relations, we consider the macroscopic electrodynamic equations for this system, which involve the standard dielectric and permeability constants plus two additional ones related to the photon self-energy functions. As an illustration, the equations are used to discuss the evolution of a magnetic field perturbation in such a medium. This particular phenomena has also been considered in a recent work by Semikoz and Sokoloff as a mechanism for the generation of large-scale magnetic fields in the Early Universe as a consequence of the neutrino-plasma interactions, and allows us to establish contact with a specific application in a well defined context, with a broader scope and from a very different point of view.
Jose' F. Nieves; Sarira Sahu
Analysis Of Factors Affecting Natural Source Slf Electromagnetic...
sensor orientation and the received artificial electromagnetic interference, influence of weather conditions on the data quality and so on. The results showed that (1) There is an...
Novel resonance-assisted electromagnetic-transport phenomena
We first demonstrate theoretically and experimentally that electromagnetic resonators with high quality factors (Q) can be used to transfer power efficiently over distances substantially larger than the characteristic ...
Kurs, Andr� B
Numerical Simulation of Electro-magnetic Turbulent Inhibitor ...
6.013 Electromagnetics and Applications, Fall 2002
Electromagnetic phenomena are explored in modern applications including wireless communications, circuits, computer interconnects and peripherals, optical fiber links and components, microwave communications and radar, ...
Staelin, David H.
Current Sheet Permeability in Electromagnetic Pulsed Plasma Thrusters
in Pulsed Electromagnetic Accelerators. PhD thesis, Princeton University, 2002. [6] R.G. Jahn and K.E. Clark
Magnetohydrodynamic power generation, electromagnetic pumps, heat pipes, and thermionic convertors
The basic principles of operation, components, and design of MHD generators, electromagnetic pumps, heat pipes and thermionic converters are described. 66 references. (WHK)
Pierson, E.S.; Bonyhady, K.A.; Dunn, P.F.; Nathenson, R.D.; Uherka, K.L.
A Numerical Evaluation Of Electromagnetic Methods In Geothermal...
GEOTHERMAL ENERGYGeothermal Home Journal Article: A Numerical Evaluation Of Electromagnetic Methods In Geothermal Exploration Details Activities (0) Areas (0) Regions (0) Abstract:...
Overview Of Electromagnetic Methods Applied In Active Volcanic...
in Colorado. For one example - Mt. Konocti in the Mayacamas Mountains, California - gravity, magnetic, and seismic, as well as electromagnetic methods have all been used in an...
Time-Domain Electromagnetics At Long Valley Caldera Area (Sorey...
released results from 158 time-domain electromagnetic (TDEM) soundings and, with Chevron Resources, a total of 77 magnetotelluric (MT) stations. Reinterpretations of the...
Experience with the EM-60 electromagnetic system for geothermal exploration in Nevada
Lawrence Berkeley Laboratory (LBL) conducted controlled-source electromagnetic (EM) surveys at three geothermal prospects in northern Nevada. Over 40 soundings were made in Panther Canyon (Grass Valley), near Winnemucca; Soda Lakes, near Fallon; and McCoy, west of Austin, to test and demonstrate the applicability of LBL's EM-60 system to geothermal exploration. The EM-60 is a frequency-domain system using three-component magnetic detection. Typically, +-65 A is applied to an 100-m-diameter four-turn horizontal loop, generating a dipole moment >10/sup 6/ MKS over the frequency range 10/sup -3/ to 10/sup -3/ Hz. With such a source loop, soundings were made, at transmitter-receiver separations of up to 4 km, providing a maximum depth of penetration of 4 km.
Wilt, M.; Goldstein, N.E.; Stark, M.; Haught, J.R.; Morrison, H.F.
From Electromagnetic Duality to Extended Electrodynamics
This paper presents the transition from Classical Electrodynamics (CED) to Extended Electrodynamics (EED) from the electromagnetic duality point of view, and emphasizes the role of the canonical complex structure in ${\\cal R}^2$ in, both, nonrelativistic and relativistic formulations of CED and EED. We begin with summarizing the motivations for passing to EED, as well as we motivate and outline the way to be followed in pursuing the right extension of Maxwell equations. Further we give the nonrelativistic and relativistic approaches to the extension and give explicitly the new equations as well as some properties of the nonlinear vacuum solutions.
Electromagnetic wave scattering by many small particles
Scattering of electromagnetic waves by many small particles of arbitrary shapes is reduced rigorously to solving linear algebraic system of equations bypassing the usual usage of integral equations. The matrix elements of this linear algebraic system have physical meaning. They are expressed in terms of the electric and magnetic polarizability tensors. Analytical formulas are given for calculation of these tensors with any desired accuracy for homogeneous bodies of arbitrary shapes. An idea to create a "smart" material by embedding many small particles in a given region is formulated.
A. G. Ramm
Physics with the ALICE Electromagnetic Calorimeter
I will present physics measurements which are achievable in the ALICE experiment at the LHC through the inclusion of a new electromagnetic calorimeter. I will focus on jet measurements in proton proton and heavy ion collisions. Detailed simulations have been performed on jet reconstruction, jet triggering, heavy flavor jet reconstruction through electron identification, gamma-jet reconstruction and the measurements of identified hadrons and resonances in jets. I will show the physics capabilities which are made possible through the combination of calorimeter information with the other detector components in ALICE.
Rene Bellwied; for the ALICE Collaboration
Survey of nucleon electromagnetic form factors
There has been much activity in the measurement of the elastic electromagnetic proton and neutron form factors in the last decade, and the quality of the data has been greatly improved by performing double polarization experiments, in compar- ison with previous unpolarized data. Here we review the experimental data base in view of the new results for the proton, and neutron, obtained at MIT-Bates, MAMI, and JLab. The rapid evolution of phenomenological models triggered by these high-precision experiments will be discussed.
Perdrisat, Charles F. [William and Mary College; Punjabi, Vina A. [Norfolk State U.
Why Study Electromagnetics: The First Unit in an Undergraduate Electromagnetics Course
integrate optical-fiber interconnects and optical microchips into systems of unimaginable information. Or could it? In fact, a simple Fourier analysis argument shows that recent optical systems that generate electromagnetic waves. For a foe determined to press an attack despite the operation of a radar system
Taflove, Allen
Assessment and Mitigation of Diagnostic-Generated Electromagnetic Interference at the National Ignition Facility
Electromagnetic interference (EMI) is an ever-present challenge at laser facilities such as the National Ignition Facility (NIF). The major source of EMI at such facilities is laser-target interaction that can generate intense electromagnetic fields within, and outside of, the laser target chamber. In addition, the diagnostics themselves can be a source of EMI, even interfering with themselves. In this paper we describe EMI generated by ARIANE and DIXI, present measurements, and discuss effects of the diagnostic-generated EMI on ARIANE's CCD and on a PMT nearby DIXI. Finally we present some of the efforts we have made to mitigate the effects of diagnostic-generated EMI on NIF diagnostics.
Brown, C G; Ayers, M J; Felker, B; Ferguson, W; Holder, J P; Nagel, S R; Piston, K W; Simanovskaia, N; Throop, A L; Chung, M; Hilsabeck, T
Numerical simulation of MHD for electromagnetic edge dam in continuous casting.
A computer model was developed to predict eddy currents and fluid flows in molten steel. The model was verified by comparing predictions with experimental results of liquid-metal containment and fluid flow in electromagnetic (EM) edge dams (EMDs) designed at Inland Steel for twin-roll casting. The model can optimize the EMD design so it is suitable for application, and minimize expensive, time-consuming full-scale testing. Numerical simulation was performed by coupling a three-dimensional (3-D) finite-element EM code (ELEKTRA) and a 3-D finite-difference fluids code (CaPS-EM) to solve heat transfer, fluid flow, and turbulence transport in a casting process that involves EM fields. ELEKTRA is able to predict the eddy-current distribution and the electromagnetic forces in complex geometries. CaPS-EM is capable of modeling fluid flows with free surfaces. Results of the numerical simulation compared measurements obtained from a static test.
Chang, F. C.
Three dimensional interpretations of single-well electromagnetic data for geothermal applications
An efficient 3-D electromagnetic (EM) inversion algorithm has been developed for geothermal applications and tested successfully using a set of single-hole EM logging data. The data was collected at an oil field undergoing CO{sub 2} injection in southern California using a single-hole EM tool, Geo-BILT, developed by Electromagnetic Instruments, Inc (EMI). The tool is equipped with a multi-component source, and multi-component receivers at different separations. The inversion result provides a reasonable electrical conductivity image to a distance of 10 m from the well, and illustrates several zones with lateral conductivity variations that could not be resolved with traditional induction logging tools. The successful case study demonstrates potential applications of the tool and software for characterizing fracture systems in geothermal reservoirs.
Tseng, Hung-Wen; Lee, Ki Ha
A fast algorithm for three-dimensional interpretations ofsingle-well electromagnetic data
An efficient inversion algorithm has been developed forthree-dimensional (3D) interpretations for single-hole electromagnetic(EM) logging data based on a modified extended Born approximation (MEBA)scheme. The single-hole data was collected at an oil field undergoing CO2injection in southern California using a tool, Geo-BILT, developed byElectromagnetic Instruments, Inc (EMI). The tool is equipped with amulti-component source, and an array of multi-component receivers atdifferent separations. The inversion result provides a reasonableelectrical conductivity image to a distance of 10 m from the well, andillustrates several zones with lateral conductivity variations that couldnot be resolved with traditional induction logging tools. The computercost of the inversion processes can be further reduced using a trivialmulti-grid methodology.
High frequency reference electrode
A high frequency reference electrode for electrochemical experiments comprises a mercury-calomel or silver-silver chloride reference electrode with a layer of platinum around it and a layer of a chemically and electrically resistant material such as TEFLON around the platinum covering all but a small ring or halo'' at the tip of the reference electrode, adjacent to the active portion of the reference electrode. The voltage output of the platinum layer, which serves as a redox electrode, and that of the reference electrode are coupled by a capacitor or a set of capacitors and the coupled output transmitted to a standard laboratory potentiostat. The platinum may be applied by thermal decomposition to the surface of the reference electrode. The electrode provides superior high-frequency response over conventional electrodes.
Kronberg, J.W.
A high frequency reference electrode for electrochemical experiments comprises a mercury-calomel or silver-silver chloride reference electrode with a layer of platinum around it and a layer of a chemically and electrically resistant material such as TEFLON around the platinum covering all but a small ring or halo' at the tip of the reference electrode, adjacent to the active portion of the reference electrode. The voltage output of the platinum layer, which serves as a redox electrode, and that of the reference electrode are coupled by a capacitor or a set of capacitors and the coupled output transmitted to a standard laboratory potentiostat. The platinum may be applied by thermal decomposition to the surface of the reference electrode. The electrode provides superior high-frequency response over conventional electrodes. 4 figs.
A high frequency reference electrode for electrochemical experiments comprises a mercury-calomel or silver-silver chloride reference electrode with a layer of platinum around it and a layer of a chemically and electrically resistant material such as TEFLON around the platinum covering all but a small ring or "halo" at the tip of the reference electrode, adjacent to the active portion of the reference electrode. The voltage output of the platinum layer, which serves as a redox electrode, and that of the reference electrode are coupled by a capacitor or a set of capacitors and the coupled output transmitted to a standard laboratory potentiostat. The platinum may be applied by thermal decomposition to the surface of the reference electrode. The electrode provides superior high-frequency response over conventional electrodes.
Kronberg, James W. (Aiken, SC)
The Localized Quantum Vacuum Field
A model for the localized quantum vacuum is proposed in which the zero-point energy of the quantum electromagnetic field originates in energy- and momentum-conserving transitions of material systems from their ground state to an unstable state with negative energy. These transitions are accompanied by emissions and re-absorptions of real photons, which generate a localized quantum vacuum in the neighborhood of material systems. The model could help resolve the cosmological paradox associated to the zero-point energy of electromagnetic fields, while reclaiming quantum effects associated with quantum vacuum such as the Casimir effect and the Lamb shift; it also offers a new insight into the Zitterbewegung of material particles.
Daniela Dragoman
Radio frequency communication system utilizing radiating transmission lines
A radio communication system for use in tunnels, mines, buildings or other shielded locations in which a pair of radiating transmission lines (30), (31) extend through such location in spaced coextensive relation to each other. Each transmission line (30), (31) has at least one unidirectional amplifier (32), (33) interposed therein with the sense of the unidirectional amplifier (32) of one transmission line (30) being opposite to the sense of the unidirectional amplifier (33) of the other transmission line (31). Each of the amplifiers (32), (33) has a gain which is less than the coupling loss between the transmission lines (30), (31). Two or more mobile transceivers (35) in the location served by the system are coupled to the transmission lines (30), (31) by electromagnetic wave propagation in space in order to communicate directly with each other at a given radio frequency within the frequency range of the system.
Struven, Warren C. (San Carlos, CA)
Cold atmospheric pressure plasma jets: Interaction with plasmid DNA and tailored electron heating using dual-frequency excitation
Recent progress in plasma science and technology has enabled the development of a new generation of stable cold non-equilibrium plasmas operating at ambient atmospheric pressure. This opens horizons for new plasma technologies, in particular in the emerging field of plasma medicine. These non-equilibrium plasmas are very efficient sources for energy transport through reactive neutral particles (radicals and metastables), charged particles (ions and electrons), UV radiation, and electro-magnetic fields. The effect of a cold radio frequency-driven atmospheric pressure plasma jet on plasmid DNA has been investigated. The formation of double strand breaks correlates well with the atomic oxygen density. Taken with other measurements, this indicates that neutral components in the jet are effective in inducing double strand breaks. Plasma manipulation techniques for controlled energy delivery are highly desirable. Numerical simulations are employed for detailed investigations of the electron dynamics, which determines the generation of reactive species. New concepts based on nonlinear power dissipation promise superior strategies to control energy transport for tailored technological exploitations.
Niemi, K.; O'Neill, C.; Cox, L. J.; Waskoenig, J.; Hyland, W. B.; McMahon, S. J.; Reuter, S.; Currell, F. J.; Graham, W. G.; O'Connell, D.; Gans, T. [Centre for Plasma Physics, Queen's University Belfast, Belfast BT7 1NN, Northern Ireland (United Kingdom)
Physics 4: Introductory Physics Electromagnetism and Light
on a charged particle; 27.1-27.2 2 Thurs, Jan 6 Properties of B-field lines; flux of B- field; motion of charged particles in B field; forces on current-carrying wire in B-field 27.3-27.6 3 Tues, Jan 11 Magnetic torques on current loops; Hall effect; B-fields produced by moving charged particles 27.7-27.9, 28.1 4
Fygenson, Deborah Kuchnir
Photographic, magnetic, and interferometric measurements of current sheet canting in a pulsed electromagnetic accelerator
in a pulsed electromagnetic accelerator were measured using three different techniques: high- speed at higher pressures. 1 Introduction Pulsed electromagnetic accelerators are devices which use intense bursts Apparatus An experimental pulsed electromagnetic accelerator has been constructed. The accelerator
Compact UWB probe for near-field microwave target detection and imaging
The numerical analysis and experimental characterization of an ultra-wideband (UWB) probe designed for near-field target detection and imaging are reported. The configuration, based on transverse electromagnetic (TEM) horn, has two curved launching planes ... Keywords: probe, resistive load, transverse electromagnetic (TEM) horn, ultra-wideband (UWB)
Jing Xia; Wa Kong; Gang Wang
Description of collisionless plasmas by classical field equations
Classical field equations are derived from quantum fields to obtain a different and possibly simpler description of a collisionless plasma. The method is to take the simultaneous limit, Dirac constant, e, m $Yields$ 0, of charged scalar fields and the electromagnetic field. Laplace transforms for perturbations in a uniform relativistic plasma are compared with corresponding results from the Maxwell--Vlasov equations. For the nonlinear case, a distribution function defined on the classical fields is shown to satisfy the Vlasov equation. (auth)
Fraley, G.S.
Method and apparatus for radio frequency ceramic sintering
Radio frequency energy is used to sinter ceramic materials. A coaxial waveguide resonator produces a TEM mode wave which generates a high field capacitive region in which a sample of the ceramic material is located. Frequency of the power source is kept in the range of radio frequency, and preferably between 60-80 MHz. An alternative embodiment provides a tunable radio frequency circuit which includes a series input capacitor and a parallel capacitor, with the sintered ceramic connected by an inductive lead. This arrangement permits matching of impedance over a wide range of dielectric constants, ceramic volumes, and loss tangents. 6 figures.
Hoffman, D.J.; Kimrey, H.D. Jr.