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Office of Scientific and Technical Information
The History of X-ray Free-Electron Lasers
Science Conference Proceedings (OSTI)
The successful lasing at the SLAC National Accelerator Laboratory of the Linear Coherent Light Source (LCLS), the first X-ray free-electron laser (X-ray FEL), in the wavelength range 1.5 to 15 {angstrom}, pulse duration of 60 to few femtoseconds, number of coherent photons per pulse from 10{sup 13} to 10{sup 11}, is a landmark event in the development of coherent electromagnetic radiation sources. Until now electrons traversing an undulator magnet in a synchrotron radiation storage ring provided the best X-ray sources. The LCLS has set a new standard, with a peak X-ray brightness higher by ten orders of magnitudes and pulse duration shorter by three orders of magnitudes. LCLS opens a new window in the exploration of matter at the atomic and molecular scales of length and time. Taking a motion picture of chemical processes in a few femtoseconds or less, unraveling the structure and dynamics of complex molecular systems, like proteins, are some of the exciting experiments made possible by LCLS and the other X-ray FELs now being built in Europe and Asia. In this paper, we describe the history of the many theoretical, experimental and technological discoveries and innovations, starting from the 1960s and 1970s, leading to the development of LCLS.
Pellegrini, C.; /UCLA /SLAC
Density gradient free electron collisionally excited x-ray laser
DOE Patents (OSTI)
An operational x-ray laser is provided that amplifies 3p-3s transition x-ray radiation along an approximately linear path. The x-ray laser is driven by a high power optical laser. The driving line focused optical laser beam illuminates a free-standing thin foil that may be associated with a substrate for improved structural integrity. This illumination produces a generally cylindrically shaped plasma having an essentially uniform electron density and temperature, that exists over a long period of time, and provides the x-ray laser gain medium. The x-ray laser may be driven by more than one optical laser beam. The x-ray laser has been successfully demonstrated to function in a series of experimental tests.
Campbell, E.M.; Rosen, M.D.
The World's First Free-Electron X-ray Laser | Department of Energy
Energy.gov (U.S. Department of Energy (DOE)) Indexed Site
First Free-Electron X-ray Laser First Free-Electron X-ray Laser The World's First Free-Electron X-ray Laser August 17, 2010 - 6:19pm Addthis The World's First Free-Electron X-ray Laser John Schueler John Schueler Former New Media Specialist, Office of Public Affairs Yesterday, Secretary Chu participated in the dedication of the world's first free-electron and most powerful X-ray laser, the Linac Coherent Light Source (LCLS). In light of this occasion (pun intended), we posted an in-depth look at the innovative nature of this new instrument and its potential to tackle some of life's biggest mysteries. The Secretary seemed just as geeked about the possibilities of the LCLS, stating that "this is a new instrument that will enable us to see the structure of materials that we could not determine by any other means ... Knowing those
The First Angstrom X-Ray Free-Electron Laser
SciTech Connect
The Linac Coherent Light Source produced its first x-ray laser beam on 10 April 2009. Today it is routinely producing x-ray pulses with energy >2 mJ across the operating range from 820-8,200 eV. The facility has begun operating for atomic/molecular/optical science experiments. Performance of the facility in its first user run (1 October - 21 December) and current machine development activities will be presented. Early results from the preparations for the start of the second user run is also reported.
Galayda, John; /SLAC
The European X-ray Free-Electron Laser: A Progress Report | Stanford...
NLE Websites -- All DOE Office Websites (Extended Search)
The European X-ray Free-Electron Laser: A Progress Report Friday, December 2, 2011 - 2:00pm SLAC, Redtail Conference Room (901-108) M. Altarelli, European XFEL GmbH, Hamburg,...
X-ray Free-Electron Lasers - Present and Future Capabilities [Invited
The Linac Coherent Light Source is now in operation as an X-ray free-electron laser (FEL) user facility. It produces coherent pulses of 550-10,000 eV X-rays of duration adjustable from <10 fsto500 fs. Typical peak power is in excess of 20 GW. The facility will soon be joined by several X-ray FELs under construction around the world. This article will provide an abridged history of free-electron lasers, a description of some basic physics regarding free-electron laser light amplification, and an overview of the rapidly growing list of examples in which lasers will be used in the control and operation of X-ray FELs.
Galayda, John; Ratner, John Arthur:a Daniel F.; White, William E.; /SLAC
Aerosol Imaging with a Soft X-ray Free Electron Laser
Lasers have long played a critical role in the advancement of aerosol science. A new regime of ultrafast laser technology has recently be realized, the world's first soft xray free electron laser. The Free electron LASer in Hamburg, FLASH, user facility produces a steady source of 10 femtosecond pulses of 7-32 nm x-rays with 10{sub 12} photons per pulse. The high brightness, short wavelength, and high repetition rate (>500 pulses per second) of this laser offers unique capabilities for aerosol characterization. Here we use FLASH to perform the highest resolution imaging of single PM2.5 aerosol particles in flight to date. We resolve to 35 nm the morphology of fibrous and aggregated spherical carbonaceous nanoparticles that existed for less than two milliseconds in vacuum. Our result opens the possibility for high spatialand time-resolved single particle aerosol dynamics studies, filling a critical technological need in aerosol science.
Bogan, Michael J.; /SLAC /LLNL, Livermore; Boutet, Sebastien; /SLAC; Chapman, Henry N.; /DESY /Hamburg U.; Marchesini, Stefano; /LBL, Berkeley; Barty, Anton; Benner, W.Henry /LLNL, Livermore; Rohner, Urs; /LLNL, Livermore /TOFWERK AG; Frank, Matthias; Hau-Riege, Stefan P.; /LLNL, Livermore; Bajt, Sasa; /DESY; Woods, Bruce; /LLNL, Livermore; Seibert, M.M.; Iwan, Bianca; Timneanu, Nicusor; Hajdu, Janos; /Uppsala U.; Schulz, Joachim; /DESY
MaRIE X-Ray Free-Electron Laser Pre-Conceptual Design
The proposed Matter-Radiation Interactions in Extremes (MaRIE) facility at the Los Alamos National Laboratory will include a 50-keV X-Ray Free-Electron Laser (XFEL), a significant extension from planned and existing XFEL facilities. To prevent an unacceptably large energy spread arsing from energy diffusion, the electron beam energy should not exceed 20 GeV, which puts a significant constraint on the beam emittance. A 100-pC baseline design is presented along with advanced technology options to increase the photon flux and to decrease the spectral bandwidth through pre-bunching the electron beam.
Carlsten, Bruce E. [Los Alamos National Laboratory; Barnes, Cris W. [Los Alamos National Laboratory; Bishofberger, Kip A. [Los Alamos National Laboratory; Duffy, Leanne D. [Los Alamos National Laboratory; Heath, Cynthia E. [Los Alamos National Laboratory; Marksteiner, Quinn R. [Los Alamos National Laboratory; Nguyen, Dinh Cong [Los Alamos National Laboratory; Russell, Steven J. [Los Alamos National Laboratory; Ryne, Robert D. [Los Alamos National Laboratory; Sheffield, Richard L. [Los Alamos National Laboratory; Simakov, Evgenya I. [Los Alamos National Laboratory; Yampolsky, Nikolai A. [Los Alamos National Laboratory
Femtosecond X-Ray Free Electron Laser Pulse Duration Measurement from Spectral Correlation Function
We present a novel method for measuring the duration of femtosecond x-ray pulses from self-amplified spontaneous emission free electron lasers by performing statistical analysis in the spectral domain. Analytical expressions of the spectral correlation function were derived in the linear regime to extract both the pulse duration and the spectrometer resolution. Numerical simulations confirmed that the method can be also used in the nonlinear regime. The method was demonstrated experimentally at the Linac Coherent Light Source by measuring pulse durations down to 13 fs FWHM.
Lutman, A. A
Simulation Studies of the X-Ray Free-Electron Laser Oscillator
Simulations of the x-ray free-electron laser (FEL) oscillator are presented that include transverse effects and realistic Bragg crystal properties with the two-dimensional code GINGER. In the present cases considered the radiation divergence is much narrower than the crystal acceptance, and the numerical algorithm can be simplified by ignoring the finite angular bandwidth of the crystal. In this regime GINGER shows that the saturated x-ray pulses have 109 photons and are nearly Fourier-limited with peak powers in excess of 1 MW. Wealso include preliminary results for a four-mirror cavity that can be tuned in wavelength over a few percent, with future plans to incorporate the full transverse response of the Bragg crystals into GINGER to more accurately model this tunable source.
Lindberg, R. R.; Shyd'ko, Y.; Kim, K.-J; Fawley, W. M.
The soft x-ray instrument for materials studies at the linac coherent light source x-ray free-electron laser
The soft x-ray materials science instrument is the second operational beamline at the linac coherent light source x-ray free electron laser. The instrument operates with a photon energy range of 480-2000 eV and features a grating monochromator as well as bendable refocusing mirrors. A broad range of experimental stations may be installed to study diverse scientific topics such as: ultrafast chemistry, surface science, highly correlated electron systems, matter under extreme conditions, and laboratory astrophysics. Preliminary commissioning results are presented including the first soft x-ray single-shot energy spectrum from a free electron laser.
Schlotter, W. F.; Turner, J. J.; Rowen, M.; Holmes, M.; Messerschmidt, M.; Moeller, S.; Krzywinski, J.; Lee, S.; Coffee, R.; Hays, G. [LCLS, SLAC National Accelerator Laboratory, 2575 Sand Hill Rd., Menlo Park, California 94025 (United States); Heimann, P. [LCLS, SLAC National Accelerator Laboratory, 2575 Sand Hill Rd., Menlo Park, California 94025 (United States); Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Krupin, O. [LCLS, SLAC National Accelerator Laboratory, 2575 Sand Hill Rd., Menlo Park, California 94025 (United States); European XFEL GmbH, Albert-Einstein-Ring 19, 22761 Hamburg (Germany); Soufli, R.; Fernandez-Perea, M.; Hau-Riege, S. [Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550 (United States); Kelez, N. [Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Beye, M.; Gerken, N.; Sorgenfrei, F.; Wurth, W. [Institute for Experimental Physics and CFEL, University of Hamburg, Luruper Chaussee 149, 22761 Hamburg (Germany); and others
Influence of diffraction in crystals on the coherence properties of X-ray free-electron laser pulses
The spatial and temporal evolution of the field of random X-ray femtosecond pulses and their coherent properties upon pulse propagation in free space and under dynamical diffraction in perfect crystals in the Bragg and Laue geometries has been analyzed on the basis of the formalism developed in statistical optics. Particular attention is paid to the influence of large pulse propagation distances, which are characteristic of lengthy channels of X-ray free-electron lasers.
Bushuev, V. A., E-mail: firstname.lastname@example.com [Moscow State University (Russian Federation); Samoylova, L. [European XFEL GmbH (Germany)
Design Optimization for an X-Ray Free Electron Laser Driven by SLAC Linac
E-Print Network (OSTI)
FREE ELECTRON LASER DRIVEN BY SLAC LINAC Ming Xie, LawrenceLaser (FEL) driven by the SLAC linac. The study assumes theis carried out for the SLAC FEL over all independent system
Xie, Ming
R&D for a Soft X-Ray Free Electron Laser Facility
Several recent reports have identified the scientific requirements for a future soft x-ray light source, and a high-repetition-rate free-electron laser (FEL) facility that is responsive to these requirements is now on the horizon. R&D in some critical areas is needed, however, to demonstrate technical performance, thus reducing technical risks and construction costs. Such a facility most likely will be based on a CW superconducting linear accelerator with beam supplied by a high-brightness, high-repetition-rate photocathode electron gun operating in CW mode, and on an array of FELs to which the accelerated beam is distributed, each operating at high repetition rate and with even pulse spacing. Dependent on experimental requirements, the individual FELs can be configured for either self-amplified spontaneous emission (SASE), seeded, or oscillator mode of operation, including the use of high-gain harmonic generation (HGHG), echo-enhanced harmonic generation (EEHG), harmonic cascade, or other configurations. In this White Paper we identify the overall accelerator R&D needs, and highlight the most important pre-construction R&D tasks required to value-engineer the design configuration and deliverables for such a facility. In Section 1.4 we identify the comprehensive R&D ultimately needed. We identify below the highest-priority requirements for understanding machine performance and reduce risk and costs at this pre-conceptual design stage. Details of implementing the required tasks will be the subject of future evaluation. Our highest-priority R&D program is the injector, which must be capable of delivering a beam with bunches up to a nanocoulomb at MHz repetition rate and with normalized emittance {le} 1 mm {center_dot} mrad. This will require integrated accelerating structure, cathode, and laser systems development. Cathode materials will impact the choice of laser technology in wavelength and energy per pulse, as well as vacuum requirements in the accelerating structure. Demonstration experiments in advanced seeding techniques, such as EEHG, and other optical manipulations to enhance the FEL process are required to reduce technical risk in producing temporally coherent and ultrashort x-ray output using optical seed lasers. Success of EEHG in particular would result in reduced development and cost of laser systems and accelerator hardware for seeded FELs. With a 1.5-2.5 GeV linac, FELs could operate in the VUV-soft x-ray range, where the actual beam energy will be determined by undulator technology; for example, to use the lower energy would require the use of advanced designs for which undulator R&D is needed. Significant reductions in both unit costs and accelerator costs resulting from the lower electron beam energy required to achieve lasing at a particular wavelength could be obtained with undulator development. Characterization of the wakefields of the vacuum chambers in narrow-gap undulators will be needed to minimize risk in ability to deliver close to transform limited pulses. CW superconducting RF technology for an FEL facility with short bunches at MHz rate and up to mA average current will require selection of design choices in cavity frequency and geometry, higher order mode suppression and power dissipation, RF power supply and distribution, accelerating gradient, and cryogenics systems. R&D is needed to define a cost and performance optimum. Developments in laser technology are proceeding at rapid pace, and progress in high-power lasers, harmonic generation, and tunable sources will need to be tracked.
Corlett, John; Attwood, David; Byrd, John; Denes, Peter; Falcone, Roger; Heimann, Phil; Leemans, Wim; Padmore, Howard; Prestemon, Soren; Sannibale, Fernando; Schlueter, Ross; Schroeder, Carl; Staples, John; Venturini, Marco; Warwick, Tony; Wells, Russell; Wilcox, Russell; Zholent, Alexander; Adolphsen, Chris; Arthur, John; Bergmann, Uwe; Cai, Yunhai; Colby, Eric; Dowell, David; Emma, Paul; Fox, John; Frisch, Josef; Galayda, John; Hettel, Robert; Huang, Zhirong; Phinney, Nan; Rabedeau, Tom; Raubenheimer, Tor; Reis, David; Schmerge, John; St�hr, Joachim; Stupakov, Gennady; White, Bill; Xiang, Dao
A setup for resonant inelastic soft x-ray scattering on liquids at free electron laser light sources
We present a flexible and compact experimental setup that combines an in vacuum liquid jet with an x-ray emission spectrometer to enable static and femtosecond time-resolved resonant inelastic soft x-ray scattering (RIXS) measurements from liquids at free electron laser (FEL) light sources. We demonstrate the feasibility of this type of experiments with the measurements performed at the Linac Coherent Light Source FEL facility. At the FEL we observed changes in the RIXS spectra at high peak fluences which currently sets a limit to maximum attainable count rate at FELs. The setup presented here opens up new possibilities to study the structure and dynamics in liquids.
Kunnus, Kristjan; Schreck, Simon; Foehlisch, Alexander [Institute for Methods and Instrumentation for Synchrotron Radiation Research, Helmholtz-Zentrum Berlin GmbH, Albert-Einstein-Strasse 15, 12489 Berlin (Germany); Institut fuer Physik und Astronomie, Universitaet Potsdam, Karl-Liebknecht-Strasse 24/25, 14476 Potsdam (Germany); Rajkovic, Ivan; Quevedo, Wilson; Gruebel, Sebastian; Scholz, Mirko [IFG Structural Dynamics of (Bio)chemical Systems, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37070 Goettingen (Germany); Eckert, Sebastian; Beye, Martin; Suljoti, Edlira; Weniger, Christian; Wernet, Philippe [Institute for Methods and Instrumentation for Synchrotron Radiation Research, Helmholtz-Zentrum Berlin GmbH, Albert-Einstein-Strasse 15, 12489 Berlin (Germany); Kalus, Christian [Abteilung Betrieb Beschleuniger BESSYII, Helmholtz-Zentrum Berlin GmbH, Albert-Einstein-Strasse 15, 12489 Berlin (Germany); Nordlund, Dennis [Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, California 94025 (United States); Zhang, Wenkai; Hartsock, Robert W.; Gaffney, Kelly J. [PULSE Institute, SLAC National Accelerator Laboratory, Menlo Park, California 94025 (United States); Schlotter, William F.; Turner, Joshua J. [Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, California 94025 (United States); Kennedy, Brian [MAX-lab, PO Box 118, 221 00 Lund (Sweden); and others
Mode-Locked Multichromatic X-Rays in a Seeded Free-Electron Laser for Single-Shot X-Ray Spectroscopy
We present the promise of generating gigawatt mode-locked multichromatic x rays in a seeded free-electron laser (FEL). We show that, by using a laser to imprint periodic modulation in electron beam phase space, a single-frequency coherent seed can be amplified and further translated to a mode-locked multichromatic output in an FEL. With this configuration the FEL output consists of a train of mode-locked ultrashort pulses which span a wide frequency gap with a series of equally spaced sharp lines. These gigawatt multichromatic x rays may potentially allow one to explore the structure and dynamics of a large number of atomic states simultaneously. The feasibility of generating mode-locked x rays ranging from carbon K edge ({approx}284 eV) to copper L{sub 3} edge ({approx}931 eV) is confirmed with numerical simulation using the realistic parameters of the linac coherent light source (LCLS) and LCLS-II. We anticipate that the mode-locked multichromatic x rays in FELs may open up new opportunities in x-ray spectroscopy (i.e. resonant inelastic x-ray scattering, time-resolved scattering and spectroscopy, etc.).
Xiang, Dao; Ding, Yuantao; Raubenheimer, Tor; Wu, Juhao; /SLAC
Microscopic linear liquid streams in vacuum: Injection of solvated biological samples into X-ray free electron lasers
Microscopic linear liquid free-streams offer a means of gently delivering biological samples into a probe beam in vacuum while maintaining the sample species in a fully solvated state. By employing gas dynamic forces to form the microscopic liquid stream (as opposed to a conventional solid-walled convergent nozzle), liquid free-streams down to 300 nm diameter have been generated. Such 'Gas Dynamic Virtual Nozzles' (GDVN) are ideally suited to injecting complex biological species into an X-ray Free Electron Laser (XFEL) to determine the structure of the biological species via Serial Femtosecond Crystallography (SFX). GDVN injector technology developed for this purpose is described.
Doak, R. B.; DePonte, D. P.; Nelson, G.; Camacho-Alanis, F.; Ros, A.; Spence, J. C. H.; Weierstall, U. [Arizona State University, Tempe, AZ 85287-1504 (United States); Centre for Free-Electron Laser Science, DESY, D-22607 Hamburg (Germany); Arizona State University, Tempe, AZ 85287-1504 (United States)
Femtosecond diffractive imaging with a soft-X-ray free-electron...
diffractive imaging with a soft-X-ray free-electron laser We have demonstrated flash diffractive imaging of nanostructures using pulses from the first soft-X-ray free-electron...
X-ray free electron lasers (xFEL) will open new avenues to the virtually unexplored territory of non-linear interactions of x rays with matter. Initially xFELs will be based on the principle of self-amplified spontaneous emission (SASE). Each SASE pulse consists of a number of coherent intensity spikes of random amplitude, i.e. the process is chaotic and pulses are irreproducible. The coherence time of SASE xFELs will be a few femtoseconds for a photon energy near 1 keV. The importance of coherence properties of light in non-linear optical processes was theoretically discovered in the early 1960s. In this contribution we will illustrate the impact of field chaoticity on x-ray non-linear optical processes on neon for photon energies around 1 keV and intensities up to 10{sup 18} W/cm{sup 2}. Resonant and non-resonant processes are discussed. The first process to be addressed is the formation of a double-core hole in neon by photoionization with x rays above 1.25 keV energy. In contrast to the long-wavelength regime, non-linear optical processes in the x-ray regime are characterized in general by sequential single-photon single-electron interactions. Despite this fact, the sequential absorption of multiple x-ray photons depends on the statistical properties of the radiation field. Treating the x rays generated by a SASE FEL as fully chaotic, a quantum-mechanical analysis of inner-shell two-photon absorption is performed. By solving a system of time-dependent rate equations, we demonstrate that double-core hole formation in neon via x-ray two-photon absorption is enhanced by chaotic photon statistics. At an intensity of 10{sup 16} W/cm{sup 2}, the statistical enhancement is about 30%, much smaller than typical values in the optical regime. The second part of this presentation discusses the resonant Auger effect of atomic neon at the 1s-3p transition (at 867.1 eV). For low X-ray intensity, the excitation process 1s {yields} 3p in Neon can be treated perturbatively. The core-hole excited 1s{sup -1} 3p state is embedded in the continuum and decays via Auger-process on the timescale of approximately 5 fs. Increasing the x-ray intensity above 1.5 x 10{sup 18} W/cm{sup 2}, a peak intensity accessible with xFEL sources in the near future, x-ray induced emission from 3p back to 1s becomes possible, i.e. Rabi oscillations between these two levels can be induced. For the numerical analysis of this process, an effective two-level model, including a description of the resonant Auger decay process, is employed. The observation of x-ray-driven atomic populations dynamics in the time domain is challenging for chaotic xFEL pulses. In addition to requiring single-shot measurements, sub-femtosecond temporal resolution would be needed. The Rabi oscillations will, however, be imprinted on the kinetic energy distribution of the resonant Auger electron (see Fig. 1). Measuring the resonant Auger-electron line profile will provide information on both atomic population dynamics and x-ray pulse properties.
Rohringer, N
The Turn-on of LCLS: the X-Ray Free Electron Laser at SLAC ( Keynote - 2011 JGI User Meeting)
The U.S. Department of Energy Joint Genome Institute (JGI) invited scientists interested in the application of genomics to bioenergy and environmental issues, as well as all current and prospective users and collaborators, to attend the annual DOE JGI Genomics of Energy & Environment Meeting held March 22-24, 2011 in Walnut Creek, Calif. The emphasis of this meeting was on the genomics of renewable energy strategies, carbon cycling, environmental gene discovery, and engineering of fuel-producing organisms. The meeting features presentations by leading scientists advancing these topics. SLAC National Laboratory Director Persis Drell gives a keynote talk on "The Turn-on of LCLS: the X-Ray Free-Electron Laser at SLAC" at the 6th Genomics of Energy & Environment Meeting on March 22, 2011
Drell, Persis [SLAC Director
Obtaining attosecond X-ray pulses using a self-amplified spontaneous emission free electron laser
1369 (2004). [10] W. B. Colson, in Laser Handbook, Volume 6:Free Elec- tron Lasers (North-Holland, Amsterdam, 1990),B. Murphy and C. Pellegrini, in Laser Handbook, Vol- ume 6:
Zholents, A.A.; Penn, G.
Low-Charge, Hard X-Ray Free Electron Laser Driven with an X-Band Injector and Accelerator
After the successful operation of the Free Electron Laser in Hamburg (FLASH) and the Linac Coherent Light Source (LCLS), soft and hard x-ray free electron lasers (FELs) are being built, designed, or proposed at many accelerator laboratories. Acceleration employing lower frequency rf cavities, ranging from L-band to C-band, is usually adopted in these designs. In the first stage bunch compression, higher-frequency harmonic rf system is employed to linearize the beam's longitudinal phase space, which is nonlinearly chirped during the lower frequency rf acceleration process. In this paper, a hard x-ray FEL design using an all X-band accelerator at 11.424 GHz (from photocathode rf gun to linac end) is presented, without the assistance of any harmonic rf linearization. It achieves LCLS-like performance at low charge using X-band linac drivers, which is more versatile, efficient, and compact than ones using S-band or C-band rf technology. It employs initially 42 microns long (rms), low-charge (10 pC) electron bunches from an X-band photoinjector. An overall bunch compression ratio of roughly 100 times is proposed in a two stage bunch compressor system. The start-to-end macroparticle 3D simulation employing several computer codes is presented in this paper, where space charge, wakefields, and incoherent and coherent synchrotron radiation effects are included. Employing an undulator with a short period of 1.5 cm, a Genesis FEL simulation shows successful lasing at a wavelength of 0.15 nm with a pulse length of 2 fs and a power saturation length as short as 20 meters, which is equivalent to LCLS low-charge mode. Its overall length of both accelerators and undulators is 180 meters (much shorter than the effective LCLS overall length of 1230 meters, including an accelerator length of 1100 meters and an undulator length of 130 meters), which makes it possible to be built in places where only limited space is available.
Sun, Yipeng; Adolphsen, Chris; Limborg-Deprey, Cecile; Raubenheimer, Tor; Wu, Juhao; /SLAC
X-ray-optical cross-correlator for gas-phase experiments at the Linac Coherent Light Source free-electron laser
X-ray-optical pump-probe experiments at the Linac Coherent Light Source (LCLS) have so far been limited to a time resolution of 280 fs fwhm due to timing jitter between the accelerator-based free-electron laser (FEL) and optical lasers. We have implemented a single-shot cross-correlator for femtosecond x-ray and infrared pulses. A reference experiment relying only on the pulse arrival time information from the cross-correlator shows a time resolution better than 50 fs fwhm (22 fs rms) and also yields a direct measurement of the maximal x-ray pulse length. The improved time resolution enables ultrafast pump-probe experiments with x-ray pulses from LCLS and other FEL sources.
Schorb, S.; Cryan, J. P.; Glownia, J. M.; Bionta, M. R.; Coffee, R. N.; Swiggers, M.; Carron, S.; Castagna, J.-C.; Bozek, J. D.; Messerschmidt, M.; Schlotter, W. F.; Bostedt, C. [Linac Coherent Light Source, SLAC National Accelerator Laboratory, P.O. Box 20450, Stanford, California 94309 (United States); Gorkhover, T. [Institut fuer Optik und Atomare Physik, Technische Universitaet Berlin, Hardenbergstr. 36, 10623 Berlin (Germany); Erk, B.; Boll, R.; Schmidt, C.; Rudenko, A. [Max-Planck Advanced-Study-Group at CFEL, Notkestr. 85, 22607 Hamburg (Germany); Max-Planck-Institut f. Kernphysik, Saupfercheckweg 1, 69117 Heidelberg (Germany); Rolles, D. [Max-Planck Advanced-Study-Group at CFEL, Notkestr. 85, 22607 Hamburg (Germany); Max-Planck-Institut f. med. Forschung, Jahnstr. 29, 69120 Heidelberg (Germany); Rouzee, A. [Max-Born-Institut, Max-Born-Str. 2, 12489 Berlin (Germany)
Compact X-ray Free Electron Laser from a Laser-plasma Accelerator using a Transverse Gradient Undulator
Compact laser-plasma accelerators can produce high energy electron beams with low emittance, high peak current but a rather large energy spread. The large energy spread hinders the potential applications for coherent FEL radiation generation. In this paper, we discuss a method to compensate the effects of beam energy spread by introducing a transverse field variation into the FEL undulator. Such a transverse gradient undulator together with a properly dispersed beam can greatly reduce the effects of electron energy spread and jitter on FEL performance. We present theoretical analysis and numerical simulations for SASE and seeded extreme ultraviolet and soft x-ray FELs based on laser plasma accelerators.
Huang, Zhirong; Ding, Yuantao; /SLAC; Schroeder, Carl B.; /LBL, Berkeley
Free Electron Laser
Free Electron Laser Building Exterior Top Floor Control Room RF Gallery User Lab Beam Enclosure Injector Linear Accelerator Wiggler Magnet Return Line Free Electron Laser Most...
1984). Colson, W. B. , "Free electron laser theory," Ph.D.M. 0. , Spitzer, R. , editors, Free Electron Generators ofM.D. , Spitzer, R. , editors, Free Electron Generators of
Colson, W.B.
1977. First Operation of a Free-Electron Laser. Phys . __Radiation from a High-Gain Free-Electeon Lasee Amplifier. ~1984. Variable-Wiggler Free-Electron-Laser Oscillat.ion.
Sessler, A.M.
Free electron lasers
A review of experimental and theoretical concepts of a free electron laser is given. The possibilities of scaling these lasers to high powers are discussed. (MOW)
Brau, C.A.
We can now produce intense, coherent light at wavelengths where no conventional lasers exist. The recent successes of devices known as free-electron lasers mark a striking confluence of two conceptual developments that themselves are only a few decades old. The first of these, the laser, is a product of the fifties and sixties whose essential characteristics have made it a staple resource in almost every field of science and technology. In a practical sense, what defines a laser is its emission of monochromatic, coherent light (that is, light of a single wavelength, with its waves locked in step) at a wavelength in the infrared, visible, or ultraviolet region of the electromagnetic spectrum. A second kind of light, called synchrotron radiation, is a by-product of the age of particle accelerators and was first observed in the laboratory in 1947. As the energies of accelerators grew in the 1960s and 70s, intense, incoherent beams of ultraviolet radiation and x--rays became available at machines built for high-energy physics research. Today, several facilities operate solely as sources of synchrotron light. Unlike the well-collimated monochromatic light emitted by lasers, however, this incoherent radiation is like a sweeping searchlight--more accurately, like the headlight of a train on a circular track--whose wavelengths encompass a wide spectral band. Now, in several laboratories around the world, researchers have exploited the physics of these two light sources and have combined the virtues of both in a single contrivance, the free-electron laser, or FEL (1). The emitted light is laserlike in its narrow, sharply peaked spectral distribution and in its phase coherence, yet it can be of a wavelength unavailable with ordinary lasers. Furthermore, like synchrotron radiation, but unlike the output of most conventional lasers, the radiation emitted by free-electron lasers can be tuned, that is, its wavelength can be easily varied across a wide range. The promise of this new technology extends from the fields of solid-state physics, gas- and liquid-phase photochemistry, and surface catalysis to futuristic schemes for ultrahigh-energy linear accelerators.
Sessler, A.M.; Vaughan, D.
Catalac free electron laser
A catalac free electron laser using a rf linac (catalac) which acts as a catalyst to accelerate an electron beam in an initial pass through the catalac and decelerate the electron beam during a second pass through the catalac is described. During the second pass through the catalac, energy is extracted from the electron beam and transformed to energy of the accelerating fields of the catalac to increase efficiency of the device. Various embodiments disclose the use of post linacs to add electron beam energy extracted by the wiggler and the use of supplementary catalacs to extract energy at various energy peaks produced by the free electron laser wiggler to further enhance efficiency of the catalac free electron laser. The catalac free electron laser can be used in conjunction with a simple resonator, a ring resonator, or as an amplifier in conjunction with a master oscillator laser.
Brau, C.A.; Swenson, D.A.; Boyd, T.J. Jr.
A catalac free electron laser using a rf linac (catalac) which acts as a catalyst to accelerate an electron beam in an initial pass through the catalac and decelerate the electron beam during a second pass through the catalac. During the second pass through the catalac, energy is extracted from the electron beam and transformed to energy of the accelerating fields of the catalac to increase efficiency of the device. Various embodiments disclose the use of post linacs to add electron beam energy extracted by the wiggler and the use of supplementary catalacs to extract energy at various energy peaks produced by the free electron laser wiggler to further enhance efficiency of the catalac free electron laser. The catalac free electron laser can be used in conjunction with a simple resonator, a ring resonator or as an amplifier in conjunction with a master oscillator laser.
Brau, Charles A. (Los Alamos, NM); Swenson, Donald A. (Los Alamos, NM); Boyd, Jr., Thomas J. (Los Alamos, NM)
Accelerator Design Study for a Soft X-Ray Free Electron Laser at the Lawrence Berkeley National Laboratory
and Phase Diagnostics, SLAC Report LCLS-TN-00-12. Emma P.al. 2009, First Results of the LCLS Laser-Heater System, PACLinac Coherent Light Source (LCLS) Conceptual Design Report,
Kur, E.
Free electron laser
A high gain, single-pass free electron laser formed of a high brilliance electron injector source, a linear accelerator which imparts high energy to the electron beam, and an undulator capable of extremely high magnetic fields, yet with a very short period. The electron injector source is the first stage (gap) of the linear accelerator or a radial line transformer driven by fast circular switch. The linear accelerator is formed of a plurality of accelerating gaps arranged in series. These gaps are energized in sequence by releasing a single pulse of energy which propagates simultaneously along a plurality of transmission lines, each of which feeds the gaps. The transmission lines are graduated in length so that pulse power is present at each gap as the accelerated electrons pass therethrough. The transmission lines for each gap are open circuited at their ends. The undualtor has a structure similar to the accelerator, except that the transmission lines for each gap are substantially short circuited at their ends, thus converting the electric field into magnetic field. A small amount of resistance is retained in order to generate a small electric field for replenishing the electron bunch with the energy lost as it traverses through the undulator structure.
Villa, Francesco (Alameda, CA)
Circular free-electron laser
A high efficiency, free electron laser is described utilizing a circular relativistic electron beam accelerator and a circular whispering mode optical waveguide for guiding optical energy in a circular path in the circular relativistic electron beam accelerator such that the circular relativistic electron beam and the optical energy are spatially contiguous in a resonant condition for free electron laser operation. Both a betatron and synchrotron are disclosed for use in the present invention. A free electron laser wiggler is disposed around the circular relativistic electron beam accelerator for generating a periodic magnetic field to transform energy from the circular relativistic electron beam to optical energy.
Brau, C.A.; Kurnit, N.A.; Cooper, R.K.
A high efficiency, free electron laser utilizing a circular relativistic electron beam accelerator and a circular whispering mode optical waveguide for guiding optical energy in a circular path in the circular relativistic electron beam accelerator such that the circular relativistic electron beam and the optical energy are spatially contiguous in a resonant condition for free electron laser operation. Both a betatron and synchrotron are disclosed for use in the present invention. A free electron laser wiggler is disposed around the circular relativistic electron beam accelerator for generating a periodic magnetic field to transform energy from the circular relativistic electron beam to optical energy.
Brau, Charles A. (Los Alamos, NM); Kurnit, Norman A. (Santa Fe, NM); Cooper, Richard K. (Los Alamos, NM)
Rf Feedback free electron laser
A free electron laser system and electron beam system for a free electron laser which use rf feedback to enhance efficiency. Rf energy is extracted from an electron beam by decelerating cavities and returned to accelerating cavities using rf returns such as rf waveguides, rf feedthroughs, etc. This rf energy is added to rf klystron energy to lower the required input energy and thereby enhance energy efficiency of the system.
Rf feedback free electron laser
A free electron laser system and electron beam system for a free electron laser are provided which use rf feedback to enhance efficiency. Rf energy is extracted from an electron beam by decelerating cavities and returned to accelerating cavities using rf returns such as rf waveguides, rf feedthroughs, etc. This rf energy is added to rf klystron energy to lower the required input energy and thereby enhance energy efficiency of the system.
Progress Toward the Wisconsin Free Electron Laser
The University of Wisconsin-Madison/Synchrotron Radiation Center is advancing its design for a seeded VUV/soft X-ray Free Electron Laser facility called WiFEL. To support this vision of an ultimate light source, we are pursuing a program of strategic R&D addressing several crucial elements. This includes development of a high repetition rate, VHF superconducting RF electron gun, R&D on photocathode materials by ARPES studies, and evaluation of FEL facility architectures (e.g., recirculation, compressor scenarios, CSR dechirping, undulator technologies) with the specific goal of cost containment. Studies of high harmonic generation for laser seeding are also planned.
Bisognano, J; Eisert, D; Fisher, M V; Green, M A; Jacobs, K; Kleman, K J; Kulpin, J; Rogers, G C; Lawler, J E; Yavuz, D
Progress toward the Wisconsin Free Electron Laser
Bisognano, Joseph; Eisert, D; Fisher, M V; Green, M A; Jacobs, K; Kleman, K J; Kulpin, J; Rogers, G C; Lawler, J E; Yavuz, D
SLAC National Accelerator Laboratory - X-ray Laser Brings Cellular...
a March experiment indicates it has, for the first time, used an X-ray free-electron laser - SLAC's Linac Coherent Light Source - to reconstitute the structure of a G...
Hybrid free electron laser devices
We consider hybrid free electron laser devices consisting of Cerenkov and undulator sections. We will show that they can in principle be used as segmented devices and also show the possibility of exploiting Cerenkov devices for the generation of nonlinear harmonic coherent power. We discuss both oscillator and amplifier schemes.
Asgekar, Vivek; Dattoli, G. [Department of Physics, University of Pune, Pune 411007 (India); ENEA, Unita Tecnico Scientifica Technologie Fisiche, Avanzate, Centro Ricerche Frascati, C.P. 65-00044 Frascati, Rome (Italy)
The potential for extending the spectral range accessible to the european X-ray free electron laser in the direction of longer wavelengths
The baseline specifications of European XFEL give a range of wavelengths between 0.1 nm and 2 nm. This wavelength range at fixed electron beam energy 17.5 GeV can be covered by operating the SASE FEL with three undulators which have different period and tunable gap. A study of the potential for the extending the spectral range accessible to the XFEL in the direction of longer wavelengths is presented. The extension of the wavelength range to 6 nm would be cover the water window in the VUV region, opening the facility to a new class of experiments. There are at least two possible sources of VUV radiation associated with the X-ray FEL; the "low (2.5 GeV) energy electron beam dedicated" and the " 17.5 GeV spent beam parasitic" (or "after-burner") source modes. The second alternative, "after-burner undulator" is the one we regard as most favorable. It is possible to place an undulator as long as 80 meters after 2 nm undulator. Ultimately, VUV undulator would be able to deliver output power approaching 100 GW. A b...
Saldin, E L; Yurkov, M V
Laser Phase Errors in Seeded Free Electron Lasers
Harmonic seeding of free electron lasers has attracted significant attention as a method for producing transform-limited pulses in the soft x-ray region. Harmonic multiplication schemes extend seeding to shorter wavelengths, but also amplify the spectral phase errors of the initial seed laser, and may degrade the pulse quality and impede production of transform-limited pulses. In this paper we consider the effect of seed laser phase errors in high gain harmonic generation and echo-enabled harmonic generation. We use simulations to confirm analytical results for the case of linearly chirped seed lasers, and extend the results for arbitrary seed laser envelope and phase.
Ratner, D.; Fry, A.; Stupakov, G.; White, W.; /SLAC
Free electron laser designs for laser amplification
Method for laser beam amplification by means of free electron laser techniques. With wiggler magnetic field strength B.sub.w and wavelength .lambda..sub.w =2.pi./k.sub.w regarded as variable parameters, the method(s) impose conditions such as substantial constancy of B.sub.w /k.sub.w or k.sub.w or B.sub.w and k.sub.w (alternating), coupled with a choice of either constant resonant phase angle or programmed phase space "bucket" area.
Prosnitz, Donald (Walnut Creek, CA); Szoke, Abraham (Fremont, CA)
Combination free electron and gaseous laser
A multiple laser having one or more gaseous laser stages and one or more free electron stages. Each of the free electron laser stages is sequentially pumped by a microwave linear accelerator. Subsequently, the electron beam is directed through a gaseous laser, in the preferred embodiment, and in an alternative embodiment, through a microwave accelerator to lower the energy level of the electron beam to pump one or more gaseous lasers. The combination laser provides high pulse repetition frequencies, on the order of 1 kHz or greater, high power capability, high efficiency, and tunability in the synchronous production of multiple beams of coherent optical radiation.
Brau, Charles A. (Los Alamos, NM); Rockwood, Stephen D. (Los Alamos, NM); Stein, William E. (Los Alamos, NM)
Free-Electron Lasers: Present Status and Future Prospects
38,892 (1977). C. Brau, "Free-Electron Lasers", Science 239,115 (1988). T. Marshall, "Free-Electron Lasers", MacMillan (1985); C Brau, "Free- Electron Lasers", Academic Press (
Kim, K.-J.
Fifth-Generation Free-Electron Laser Light Sources
During the past few years, the Linac Coherent Light Source (LCLS) and the Free-Electron Laser in Hamburg (FLASH) have demonstrated the outstanding capability of free-electron lasers (FELs) as sources of coherent radiation in the soft and hard x-ray region. The high intensity, tens of GW, short pulses (few to less than 100 femtoseconds, and the unique transverse coherence properties are opening a new window to study the structure and dynamics of atomic and molecular systems. The LCLS, FLASH, and the other FELs now under construction are only the beginning of the development of these light sources. The next generations will reach new levels of performance: terawatt, atto-second, ultra-small line-width, high repetition rate, full longitudinal and transverse coherence. These future developments and the R&D needed to successfully build and operate the next generation of FEL light sources will be discussed.
Pellegrini, Claudio [UCLA
Design Alternatives for a Free Electron Laser Facility
The University of Wisconsin-Madison is continuing design efforts for a vacuum ultraviolet/X-ray Free Electron Laser facility. The design incorporates seeding the FEL to provide fully coherent photon output at energies up to {approx}1 keV. The focus of the present work is to minimize the cost of the facility while preserving its performance. To achieve this we are exploring variations in the electron beam driver for the FEL, in undulator design, and in the seeding mechanism. Design optimizations and trade-offs between the various technologies and how they affect the FEL scientific program will be presented.
Jacobs, K; Bosch, R A; Eisert, D; Fisher, M V; Green, M A; Keil, R G; Kleman, K J; Kulpin, J G; Rogers, G C; Wehlitz, R; Chiang, T; Miller, T J; Lawler, J E; Yavuz, D; Legg, R A
Short pulse free electron laser amplifier
Method and apparatus for amplification of a laser pulse in a free electron laser amplifier where the laser pulse duration may be a small fraction of the electron beam pulse duration used for amplification. An electron beam pulse is passed through a first wiggler magnet and a short laser pulse to be amplified is passed through the same wiggler so that only the energy of the last fraction, f, (f<1) of the electron beam pulse is consumed in amplifying the laser pulse. After suitable delay of the electron beam, the process is repeated in a second wiggler magnet, a third, . . . , where substantially the same fraction f of the remainder of the electron beam pulse is consumed in amplification of the given short laser pulse in each wiggler magnet region until the useful electron beam energy is substantially completely consumed by amplification of the laser pulse.
Schlitt, Leland G. (Livermore, CA); Szoke, Abraham (Fremont, CA)
X?ray Fluorescence (XRF) Assay Using Laser Compton Scattered (LCS) X?rays
Laser Compton Scattered (LCS) X?rays are produced as a result of the interaction between accelerated electrons and a laser beam. The yield of LCS X?rays is dependent on the laser power
Syed F. Naeem; Khalid Chouffani; Douglas P. Wells
World's First Hard X-ray Laser
LCLS is the world's most powerful X-ray laser. Its highly focused beam, which arrives in staccato bursts a few quadrillionths of a second long, allows researchers to probe complex,...
Free-electron laser driven by the LBNL laser-plasma accelerator
Free-electron laser driven by the LBNL laser-plasmaA design of a compact free-electron laser (FEL), generatingare considered. Keywords: Free-electron laser, laser-plasma
Schroeder, C. B.
Free electron laser with masked chicane
A free electron laser (FEL) is provided with an accelerator for outputting electron beam pulses; a buncher for modulating each one of the electron beam pulses to form each pulse into longitudinally dispersed bunches of electrons; and a wiggler for generating coherent light from the longitudinally dispersed bunches of electrons. The electron beam buncher is a chicane having a mask for physically modulating the electron beam pulses to form a series of electron beam bunches for input to the wiggler. In a preferred embodiment, the mask is located in the chicane at a position where each electron beam pulse has a maximum dispersion.
Nguyen, Dinh C. (Los Alamos, NM); Carlsten, Bruce E. (Los Alamos, NM)
Beam Conditioning for Free Electron Lasers:Consequences and Methods
The consequences of beam conditioning in four example cases [VISA, a soft x-ray free-electron laser (FEL), LCLS, and a 'Greenfield' FEL] are examined. It is shown that in emittance limited cases, proper conditioning reduces sensitivity to the transverse emittance and, furthermore, allows for stronger focusing in the undulator. Simulations show higher saturation power, with gain lengths reduced by a factor of 2 or more. The beam dynamics in a general conditioning system are studied, with 'matching conditions' derived for achieving conditioning without growth in the effective emittance. Various conditioning lattices are considered, and expressions derived for the amount of conditioning provided in each case when the matching conditions are satisfied. These results show that there is no fundamental obstacle to producing beam conditioning, and that the problem can be reduced to one of proper lattice design. Nevertheless, beam conditioning will not be easy to implement in practice.
Wolski, A.; Penn, G.; Sessler, A.; Wurtele, J.; /LBL, Berkeley /UC, Berkeley, Astron. Dept.
Airborne Tactical Free-Electron Laser
The goal of 100 kilowatts (kW) of directed energy from an airborne tactical platform has proved challenging due to the size and weight of most of the options that have been considered. However, recent advances in Free-Electron Lasers appear to offer a solution along with significant tactical advantages: a nearly unlimited magazine, time structures for periods from milliseconds to hours, radar like functionality, and the choice of the wavelength of light that best meets mission requirements. For an Airborne Tactical Free-Electron Laser (ATFEL) on a platforms such as a Lockheed C-130J-30 and airships, the two most challenging requirements, weight and size, can be met by generating the light at a higher harmonic, aggressively managing magnet weights, managing cryogenic heat loads using recent SRF R&D results, and using FEL super compact design concepts that greatly reduce the number of components. The initial R&D roadmap for achieving an ATFEL is provided in this paper. Performing this R&D is expected to further reduce the weight, size and power requirements for the FELs the Navy is currently developing for shipboard applications, as well as providing performance enhancements for the strategic airborne MW class FELs. The 100 kW ATFEL with its tactical advantages may prove sufficiently attractive for early advancement in the queue of deployed FELs.
Roy Whitney; George Neil
Fluctuation X-Ray Scattering
The work supported by the grant was aimed at developing novel methods of finding the structures of biomolecules using x-rays from novel sources such as the x-ray free electron laser and modern synchrotrons
Saldin, PI: D. K.; Co-I's: J. C. H. Spence and P. Fromme
LCLS - The X-ray Laser Has Turned On
On April 10, 2009 the Linac Coherent Light Source (LCLS), the world's first hard x-ray free electron laser, was brought to lasing. Producing an x-ray beam with over a billion times higher peak brightness that then most powerful existing syncrotron sources, it marked the beginning of a new era of science. The LCLS pulses arrive at a rate of 60 - 120 Hz in an energy range from 480 eV to 10 keV, with pulse lengths as short as a few fs to about 300 fs. Since October 2009, users have been performing experiments at the LCLS, and currently three of the six planned instruments are available. Although we stand only at the beginning of LCLS science, there is no doubt about the strong sense of early excitement.
Bergmann, Uwe [Linac Coherent Light Source
Rippled beam free electron laser amplifier
A free electron laser amplifier provides a scalloping annular electron beam that interacts with the axial electric field of a TM.sub.0n mode. A waveguide defines an axial centerline and, a solenoid arranged about the waveguide produces an axial constant magnetic field within the waveguide. An electron beam source outputs a annular electron beam that interacts with the axial magnetic field to have an equilibrium radius and a ripple radius component having a variable radius with a ripple period along the axial centerline. An rf source outputs an axial electric field that propagates within the waveguide coaxial with the electron beam and has a radial mode that interacts at the electron beam at the equilibrium radius component of the electron beam.
Carlsten, Bruce E. (Los Alamos, NM)
Rippled beam free electron Laser Amplifier
A free electron laser amplifier provides a scalloping annular electron beam that interacts with the axial electric field of a T{sub 0n} mode. A waveguide defines an axial centerline and . A solenoid arranged about the waveguide produces an axial constant magnetic field within the waveguide. An electron beam source outputs a annular electron beam that interacts with the axial magnetic field to have an equilibrium radius and a ripple radius component having a variable radius with a ripple period along the axial centerline. An rf source outputs an axial electric field that propagates within the waveguide coaxial with the electron beam and has a radial mode that interacts at the electron beam at the equilibrium radius component of the electron beam.
Carlsten, Bruce E.
Soft x-ray laser microscope
The program consisted of two phases (Phase I and Phase II). The goal of the Phase I (first year program) was to design and construct the Soft X-ray Laser Contact Microscope. Such microscope was constructed and adapted to PPL's 18.2nm soft X-ray Laser (SXL), which in turn was modified and prepared for microscopy experiments. Investigation of the photoresist response to 18.2nm laser radiation and transmissivity of 0.1m thick silicion-nitride (Si[sub 3]N[sub 4]) windows were important initial works. The goal of the first year of Phase II was to construct X-ray contact microscope in combination with existing optical phase microscope, already used by biologists. In the second year of Phase II study of dehydrated Horeseshoe Crab and Hela cancer cells were performed with COXRALM. Also during Phase II, the Imaging X-Ray Laser Microscope (IXRALM) was designed and constructed. This paper describes the development of each of the microscopes and their application for research.
Suckewer, P.I.
SLAC National Accelerator Laboratory - X-ray Laser Helps Fight...
human health. "This is the first new biological structure solved with a free-electron laser," said Henry Chapman of the Center for Free-Electron Laser Science in Hamburg,...
SLAC National Accelerator Laboratory - SLAC's X-ray Laser Explores...
X-ray Laser Explores Big Data Frontier By Glenn Roberts Jr. June 12, 2013 It's no surprise that the data systems for SLAC's Linac Coherent Light Source X-ray laser have drawn...
Ignition feedback regenerative free electron laser (FEL) amplifier
An ignition feedback regenerative amplifier consists of an injector, a linear accelerator with energy recovery, and a high-gain free electron laser amplifier. A fraction of the free electron laser output is coupled to the input to operate the free electron laser in the regenerative mode. A mode filter in this loop prevents run away instability. Another fraction of the output, after suitable frequency up conversion, is used to drive the photocathode. An external laser is provided to start up both the amplifier and the injector, thus igniting the system.
Kim, Kwang-Je (Burr Ridge, IL); Zholents, Alexander (Walnut Creek, CA); Zolotorev, Max (Oakland, CA)
Wiggler plane focusing in a linear free electron laser
Free electron laser apparatus that provides a magnetic centering force to turn or focus a non-axial electron toward the longitudinal axis as desired. The focusing effect is provided by wiggler magnet pole faces that are approximately parabolically shaped.
Scharlemann, Ernst T. (Livermore, CA)
Free electron laser using Rf coupled accelerating and decelerating structures
A free electron laser and free electron laser amplifier using beam transport devices for guiding an electron beam to a wiggler of a free electron laser and returning the electron beam to decelerating cavities disposed adjacent to the accelerating cavities of the free electron laser. Rf energy is generated from the energy depleted electron beam after it emerges from the wiggler by means of the decelerating cavities which are closely coupled to the accelerating cavities, or by means of a second bore within a single set of cavities. Rf energy generated from the decelerated electron beam is used to supplement energy provided by an external source, such as a klystron, to thereby enhance overall efficiency of the system.
Hard x-ray or gamma ray laser by a dense electron beam
A dense electron beam propagating through a laser undulator can radiate a coherent x-ray or gamma ray. This lasing scheme is studied with the Landau damping theory. The analysis suggests that, with currently available physical parameters, coherent gamma rays of up to 50 keV can be generated. The electron quantum diffraction suppresses the free electron laser action, which limits the maximum radiation.
Son, S. [18 Caleb Lane, Princeton, New Jersey 08540 (United States); Joon Moon, Sung [8 Benjamin Rush Ln., Princeton, New Jersey 08540 (United States)
Single electron beam rf feedback free electron laser
A free electron laser system and electron beam system for a free electron laser which uses rf feedback to enhance efficiency are described. Rf energy is extracted from a single electron beam by decelerating cavities and energy is returned to accelerating cavities using rf returns, such as rf waveguides, rf feedthroughs, resonant feedthroughs, etc. This rf energy is added to rf klystron energy to reduce the required input energy and thereby enhance energy efficiency of the system.
Brau, C.A.; Stein, W.E.; Rockwood, S.D.
Free-electron-laser design for laser amplification
A method for laser beam amplification by means of free electron laser techniques is described. With wiggler magnetic field strength B/sub w/ and wavelength lambda/sub w/ = 2..pi../k/sub w/ regarded as variable parameters, the method(s) impose conditions such as substantial constancy of B/sub w//k/sub w/ or k/sub w/ or B/sub w/ and k/sub w/ (alternating), coupled with a choice of either constant resonant phase angle or programmed phase space bucket area.
Prosnitz, D.; Szoke, A.
SLAC National Accelerator Laboratory - X-ray Laser Pulses in...
SLAC researchers have demonstrated for the first time how to produce pairs of X-ray laser pulses in slightly different wavelengths, or colors, with finely adjustable intervals...
S.M. Gold, et. al. , in Free Electron Generators of CoherentThe Hughes Low-Voltage Free-Electron Laser Program," inProc. of the 1985 Free Electron Laser Conference, Lake
Two-dimensional optimization of free electron laser designs
Off-axis, two-dimensional designs for free electron lasers that maintain correspondence of a light beam with a "synchronous electron" at an optimal transverse radius r>0 to achieve increased beam trapping efficiency and enhanced laser beam wavefront control so as to decrease optical beam diffraction and other deleterious effects.
Prosnitz, Donald (Walnut Creek, CA); Haas, Roger A. (Pleasanton, CA)
Two-dimensional optimization of free-electron-laser designs
Off-axis, two-dimensional designs for free electron lasers are described that maintain correspondence of a light beam with a synchronous electron at an optimal transverse radius r > 0 to achieve increased beam trapping efficiency and enhanced laser beam wavefront control so as to decrease optical beam diffraction and other deleterious effects.
Prosnitz, D.; Haas, R.A.
High-efficiency free-electron laser results
Results obtained with a tapered-wiggler free-electron laser demonstrate the concepts proposed by Morton for enhanced efficiency and show deceleration of electrons by as much as 7%, and extraction of more than 3% of the total electron-beam energy as laser energy when the laser is operated as an amplifier. The experiment is presently being reconfigured to examine its performance as a laser oscillator.
Boyer, K.; Baru, C.A.; Newnam, B.E.; Stein, W.E.; Warren, R.W.; Winston, J.G.; Young, L.M.
Multifrequency, single pass free electron laser
A method for simultaneous amplification of laser beams with a sequence of frequencies in a single pass, using a relativistic beam of electrons grouped in a sequence of energies corresponding to the sequence of laser beam frequencies. The method allows electrons to pass from one potential well or "bucket" to another adjacent bucket, thus increasing efficiency of trapping and energy conversion.
Szoke, Abraham (Fremont, CA); Prosnitz, Donald (Walnut Creek, CA)
Ultrafast time dynamics studies of periodic lattices with free electron laser radiation
It has been proposed that radiation from free electron laser (FEL) at Hamburg (FLASH) can be used for ultrafast time-resolved x-ray diffraction experiments based on the near-infrared (NIR) pump/FEL probe scheme. Here, investigation probing the ultrafast structural dynamics of periodic nano-crystalline organic matter (silver behenate) with such a scheme is reported. Excitation with a femtosecond NIR laser leads to an ultrafast lattice modification which time evolution has been studied through the scattering of vacuum ultraviolet FEL pulses. The found effect last for 6 ps and underpins the possibility for studying nanoperiodic dynamics down to the FEL source time resolution. Furthermore, the possibility of extending the use of silver behenate (AgBh) as a wavelength and temporal calibration tool for experiments with soft x-ray/FEL sources is suggested.
Quevedo, W.; Busse, G.; Hallmann, J.; More, R.; Petri, M.; Rajkovic, I. [Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Goettingen (Germany); Krasniqi, F.; Rudenko, A. [Max Planck Advanced Study Group at CFEL, Notkestrasse 85, 22607 Hamburg (Germany); Tschentscher, T. [European XFEL GmbH, Albert-Einstein-Ring 19, 22671 Hamburg (Germany); Stojanovic, N.; Duesterer, S.; Treusch, R.; Tolkiehn, M. [HASYLAB at DESY, Notkestrasse 85, 22607 Hamburg (Germany); Techert, S. [Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Goettingen (Germany); Max Planck Advanced Study Group at CFEL, Notkestrasse 85, 22607 Hamburg (Germany)
X-ray emission from laser-produced plasmas
The intensity and spectral characteristics of x-ray emitted from laser-produced plasmas have been investigated computatinoally and experimentally. a two-dimensional implosi code was used successfully to calculate laser-plasma radiation characteristics and to aid in the design of laser targets for high-yield x-ray production. Other computer codes, in use or under development predict lime strengths and energies for laser-plasma x-ray emission. An experimental effort is aimed at reliable measurements of x-ray yields and spectra. a wide variety of x-ray detection methods have been evaluated, and x-ray yields have been measured from plasmas produced with two dissimilar laser systems. The high energy x-ray spectrum, from about 10 to 140 keV, has been studied using high-gain scintillatino detectors and thick K-edge filters. Various supplementary measurements have provided information concerning characteristics of the target-reflected laser light, the ion energies, and the laser intensity patterns.
Violet, C.E. [ed.
SLAC National Accelerator Laboratory - X-ray Laser Research Ranks...
selected science "Breakthrough of the Year": the discovery of what appears to be the Higgs boson. Scientists aimed the Linac Coherent Light Source X-ray laser at thousands of tiny...
SLAC National Accelerator Laboratory - X-ray Laser Takes Aim...
Laser Takes Aim at Cosmic Mystery December 12, 2012 Menlo Park, Calif. - Scientists have used powerful X-rays from the Linac Coherent Light Source (LCLS) at the U.S. Department of...
SLAC National Accelerator Laboratory - X-ray Laser Sees Photosynthesis...
new window on the way plants generate the oxygen we breathe, researchers used an X-ray laser at the Department of Energy's (DOE) SLAC National Accelerator Laboratory to...
A Proof-of-Principle Echo-enabled Harmonic Generation Free Electron Laser Experiment at SLAC
With the advent of X-ray Free Electron Lasers (FELs), new methods have been developed to extend capabilities at short wavelengths beyond Self-Amplified Spontaneous Emission (SASE). In particular, seeding of a FEL allows for temporal control of the radiation pulse and increases the peak brightness by orders of magnitude. Most recently, Gennady Stupakov and colleagues at SLAC proposed a new technique: Echo-Enabled Harmonic Generation (EEHG). Here a laser microbunches the beam in an undulator and the beam is sheared in a chicane. This process is repeated with a second laser, undulator and chicane. The interplay between these allows a seeding of the X-ray laser up to the 100th harmonic of the first laser. After introducing the physics of FELs and the EEHG seeding technique, we describe contributions to the experimental effort. We will present detailed studies of the experiment including the choice of parameters and their optimization, the emittance effect, spontaneous emission in the undulators, the second laser phase effect, and measurements of the jitter between RF stations. Finally, the status and preliminary results of the Echo-7 experiment will be outlined.
Pernet, Pierre-Louis; /Ecole Polytechnique, Lausanne /SLAC
Chirped pulse inverse free-electron laser vacuum accelerator
A chirped pulse inverse free-electron laser (IFEL) vacuum accelerator for high gradient laser acceleration in vacuum. By the use of an ultrashort (femtosecond), ultrahigh intensity chirped laser pulse both the IFEL interaction bandwidth and accelerating gradient are increased, thus yielding large gains in a compact system. In addition, the IFEL resonance condition can be maintained throughout the interaction region by using a chirped drive laser wave. In addition, diffraction can be alleviated by taking advantage of the laser optical bandwidth with negative dispersion focusing optics to produce a chromatic line focus. The combination of these features results in a compact, efficient vacuum laser accelerator which finds many applications including high energy physics, compact table-top laser accelerator for medical imaging and therapy, material science, and basic physics.
Hartemann, Frederic V. (Dublin, CA); Baldis, Hector A. (Pleasanton, CA); Landahl, Eric C. (Walnut Creek, CA)
FREE ELECTRON LASER FOR SIBERIAN CENTRE FOR PHOTOCHEMICAL RESEARCH: THE CONTROL SYSTEM of the Siberian Branch of RAS. Abstract. A control system for the magnetic system of the free electron laser (FEL
Kozak, Victor R.
In the OSTI Collections: Free-Electron Lasers | OSTI, US Dept of Energy,
Office of Scientific and Technical Information (OSTI)
Free-Electron Lasers Free-Electron Lasers Existing Free-Electron Lasers Using Free-Electron Lasers for Measurement and Defense New Free-Electron Laser Designs References Research Organizations Reports available from OSTI's Information Bridge While most types of laser produce coherent light from electric charges bound within atoms, molecules, or solids, unbound charges are the light source in free-electron lasers. Lasers of this type can operate at higher frequencies than are easily achieved with bound-electron lasers. Various uses and designs of free-electron lasers are the focus of different projects sponsored through the Department of Energy. Lasers, like any source of light or other electromagnetic waves, produce waves when some of the electric charges they contain go from having a
X-ray emission from colliding laser plasmas
Colliding Au, CD and Ti-Cr plasmas have been generated by illuminating two opposing foils each with a {approximately} 100J, 0.5 nsec, 2{omega} Nd-glass laser beam from the Trident laser facility at Los Alamos. The plasmas are being used to study plasma interactions which span the parameter regime from interpenetrating to collisional stagnation. X-ray emission during the laser target interaction and the subsequent collision is used to diagnose the initial plasma conditions and the colliding plasma properties. X-ray instrumentation consists of a 100 ps gated x-ray pinhole imager, a time-integratcd bremsstrahlung x-ray spectrograph and a gated x-ray spectrograph used to record isoelectronic spectra from the Ti-Cr plasmas. The imager has obtained multi-frame images of the collision and therefore, a measure of the stagnation length which is a function of the ion charge state and density and a strong function of the electron temperature. Other instrumentation includes a Thomson scattering spectrometer with probe beam, neutron detectors used to monitor the CD coated foil collisions and an ion spectrometer. We will describe the current status of the experiments and current results with emphasis on the x-ray emission diagnostics. We will also briefly describe the modeling using Lasnex and ISIS, a particle-in-cell code with massless fluid electrons and inter particle (classical) collisions.
Wilke, M.; Obst, A.W.; Winske, D. [and others
Laser assisted Compton scattering of X-ray photons
The Compton scattering of X-ray photons, assisted by a short intense optical laser pulse is discussed. The differential scattering cross section reveals the interesting feature that the main Klein-Nishina line is accompanied by a series of side-lines forming a broad plateau where up to ${\\cal O} (10^3)$ laser photons participate simultaneously in a single scattering event. Due to the non-linear mixing of X-ray and laser photons a frequency dependent rotation of the polarization of the final state photons relative to the scattering plane emerges. A consistent description of the scattering process with short laser pulses requires to work with X-ray pulses. An experimental investigation can be accomplished, e.g., at LCLS or the European XFEL in the near future.
D. Seipt; B. Kampfer
Vanadium-pumped titanium x-ray laser
A resonantly photo-pumped x-ray laser (10) is formed of a vanadium (12) and titanium (14) foil combination (16) that is driven by two beams (18, 20) of intense line focused (22, 24) optical laser radiation. Ground state neon-like titanium ions (34) are resonantly photo-pumped by line emission from fluorine-like vanadium ions (32).
Nilsen, Joseph (Livermore, CA)
A resonantly photo-pumped x-ray laser is formed of a vanadium and titanium foil combination that is driven by two beams of intense line focused optical laser radiation. Ground state neon-like titanium ions are resonantly photo-pumped by line emission from fluorine-like vanadium ions.
Nilsen, J.
Ultrafast x-ray diagnostics for laser fusion experiments
Temporally, spectrally, and spatially resolved x-ray emission diagnostics are important tools in the study of the heating and compression of laser fusion targets by sub-nanosecond laser pulses. The use of the Livermore 15 psec resolution x-ray streak camera to make such measurements is reviewed. Temporal histories of spectrally resolved x-ray emission in the 1 to 10 keV range have been obtained. These data have served to further define the x-ray streak camera as a quantative diagnostic tool and have also provided data relating to the absorption and compression phases of laser heating. The x-ray streak camera has been used in conjunction with a specially designed pinhole imaging system to temporally record images of laser compressed targets with a spatial resolution of approximately 6 ..mu..m. Implosion characteristics are presented for experiments with glass microshell targets. The concept, development, and testing of an ultrafast framing camera for full two-dimensional time resolved imaging is discussed. A prototype camera, based on the image dissection-restoration concept, has achieved an approximately 200 psec frame period with a resolution of 50 ..mu..m.
Coleman, L.W.
The LLNL/UCLA high gradient inverse free electron laser
We describe the Inverse Free Electron Accelerator currently under construction at Lawrence Livermore National Lab. Upon completion of this accelerator, high brightness electrons generated in the photoinjector blowout regime and accelerated to 50 MeV by S-band accelerating sections will interact with > 4 TW peak power Ti:Sapphire laser in a highly tapered 50 cm undulator and experience an acceleration gradient of > 200 MeV/m. We present the final design of the accelerator as well as the results of start-to-end simulations investigating preservation of beam quality and tolerances involved with this accelerator.
Moody, J. T.; Musumeci, P.; Anderson, G.; Anderson, S.; Betts, S.; Fisher, S.; Gibson, D.; Tremaine, A.; Wu, S. [Department of Physics and Astronomy, UCLA, Los Angeles California, 90095 (United States); Lawrence Livermore National Laboratory (United States)
Compact two-beam push-pull free electron laser
An ultra-compact free electron laser comprising a pair of opposed superconducting cavities that produce identical electron beams moving in opposite directions such that each set of superconducting cavities accelerates one electron beam and decelerates the other electron beam. Such an arrangement, allows the energy used to accelerate one beam to be recovered and used again to accelerate the second beam, thus, each electron beam is decelerated by a different structure than that which accelerated it so that energy exchange rather than recovery is achieved resulting in a more compact and highly efficient apparatus.
Hutton, Andrew (Yorktown, VA)
Puffin: A three dimensional, unaveraged free electron laser simulation code
An unaveraged 3D model of the free electron laser (FEL) is presented which is capable of modelling electron interactions with broad bandwidth radiation that includes electron beam shot-noise and coherent spontaneous emission effects. Non-localised electron transport throughout the beam is modelled self-consistently allowing better modelling of systems where a larger electron energy range is required. The FEL interaction can be modelled with undulator fields of variable polarisation. A modular undulator system allows insertion of other magnetic structures, such as chicanes. A set of working equations that describe the model are derived, the parallel numerical method that solves them described, and some example FEL interactions presented.
Campbell, L. T. [University of Strathclyde (SUPA), Glasgow G4 0NG (United Kingdom); ASTeC, STFC Daresbury Laboratory and Cockcroft Institute, Warrington WA4 4AD (United Kingdom); McNeil, B. W. J. [University of Strathclyde (SUPA), Glasgow G4 0NG (United Kingdom)
Desktop megawatt superradiant free-electron laser at terahertz frequencies
I present a theoretical and simulation study of a desktop, megawatt (MW), terahertz (THz) superradiance free-electron laser (FEL) driven by a THz-pulse-train photoinjector. With nominal electron parameters from a THz-pulse-train photoinjector, this superradiant FEL is capable of generating more than 5 MW power at THz frequencies from a half-meter, single-pass undulator. Tapering the undulator to a length of 1.5 m can further increase the FEL output power to nearly 15 MW.
Huang, Y.-C. [Department of Electrical Engineering, National Tsinghua University, Hsinchu 30013, Taiwan (China)
Investigation of efficiency optimization in free electron lasers
The dynamics of trapped particles in the presence of the wiggler magnetic field and the electromagnetic radiation field in free electron lasers were investigated. From the results of computer simulations, it was found that, for a given set of parameters, the efficiency of energy extraction from the electron beam maximizes at a particular intensity of the electromagnetic radiation. Based on the physical argument of the dynamics of the trapped particles, a criterion which predicts accurately the optimum intensity of the electromagnetic radiation was obtained. (TFD)
Kwan, T.J.T.
Inverse Free Electron Laser Heater for the LCLS
The Linac Coherent Light Source (LCLS) free electron laser employs an RF photocathode gun that yields a 1nC bunch a few picoseconds long, which must be further compressed to yield the high current required for Self Amplified Spontaneous Emission (SASE) gain. The electron beam from the RF photocathode gun is quite sensitive to microbunching instabilities such as coherent synchrotron radiation (CSR) in the compressor chicanes and longitudinal space charge (LSC) in the linac. These effects can be Landau damped by adding energy spread to the electron bunch prior to compression. They propose to do this by co-propagating an infrared laser beam with the electron bunch in an undulator in the LCLS injector beamline. The undulator is placed in a four bend magnet chicane to allow the Ir laser beam to propagate colinearly with the e-beam while it oscillates in the undulator. The IR laser beam is derived from the photocathode gun drive laser, so the two beams are synchronized. Simulations presented elsewhere in these proceedings show that the laser interaction damps the microbunching instabilities to a very great extent. This paper is a description of the design of the laser heater.
Bentson, L.D.; Bolton, P.; Carr, R.; Dowell, D.; Emma, P.; Gilevich, S.; Huang, Z.; Welch, J.J.; Wu, J.; /SLAC
Analysis of Coherence Properties of 3-rd Generation Synchrotron Sources and Free-Electron Lasers
A general theoretical approach based on the results of statistical optics is used for the analysis of the transverse coherence properties of 3-rd generation synchrotron sources and x-ray free-electron lasers (XFEL). Correlation properties of the wavefields are calculated at different distances from an equivalent Gaussian Schell-model source. This model is used to describe coherence properties of the five meter undulator source at the synchrotron storage ring PETRA III. In the case of XFEL sources the decomposition of the statistical fields into a sum of independently propagating transverse modes is used for the analysis of the coherence properties of these new sources. A detailed calculation is performed for the parameters of the SASE1 undulator at the European XFEL. It is demonstrated that only a few modes contribute significantly to the total radiation field of that source.
Vartanyants, I A
Beam conditioner for free electron lasers and synchrotrons
A focused optical is been used to introduce an optical pulse, or electromagnetic wave, colinearly with the electron beam in a free electron laser or synchrotron thereby adding an axial field component that accelerates the electrons on the radial outside of the distribution of electrons in the electron beam. This invention consists of using the axial electrical component of a TEM.sub.10 mode Gaussian beam in vacuum to condition the electron beam and speed up the outer electrons in the beam. The conditioning beam should possess about the same diameter as the electron beam. The beam waist of the conditioning wave must be located around the entrance of the undulator longitudinally to have a net energy exchange between the electrons in the outer part of the distribution and the conditioning wave owing to the natural divergence of a Gaussian beam. By accelerating the outer electrons, the outer and core electrons are caused to stay in phase. This increases the fraction of the electron beam energy that is converted to light thereby improving the efficiency of conversion of energy to light and therefore boosting the power output of the free electron laser and synchrotron.
Liu, Hongxiu (Williamsburg, VA); Neil, George R. (Williamsburg, VA)
DOE Science Showcase - Free-Electron Lasers | OSTI, US Dept of Energy,
Free-Electron Lasers Free-Electron Lasers Free-Electron Lasers absorb and release energy at any wavelength and can be controlled more precisely than conventional lasers by producing intense powerful light in brief bursts with extreme precision. This innovative technology has opened doors to a vast array of possibilities for manufacturing and for basic research. Read more in the white paper In OSTI Collections: Free-Electron Lasers by Dr. William Watson, Physicist, OSTI staff. Free-Electron Lasers Results in DOE Databases Science.gov Ciencia.Science.gov (Español) WorldWideScience.org Energy Citations Database DOE Information Bridge Relevant Subject Clusters FREE ELECTRON LASERS PARTICLE ACCELERATORS ENGINEERING LASERS ELECTRON BEAMS ACCELERATORS WIGGLER MAGNETS EQUIPMENT ELECTROMAGNETIC RADIATION
The Next Challenge in X-Ray Science: Control of Resonant Electronic...
and the implications for future scientific opportunities with x-ray free electron lasers (X-FELs). The historical journey starts with the development of radar microwave...
Reliable before-fabrication forecasting of expected surface slope distributions for x-ray optics
of x-ray optics for the LCLS free-electron laser,� Proc.beamlines and diagnostics at LCLS,� Nucl. Instrum. Methods A
Yashchuk, Yekaterina V.
Soft x-ray laser microscope. Final report
The program consisted of two phases (Phase I and Phase II). The goal of the Phase I (first year program) was to design and construct the Soft X-ray Laser Contact Microscope. Such microscope was constructed and adapted to PPL`s 18.2nm soft X-ray Laser (SXL), which in turn was modified and prepared for microscopy experiments. Investigation of the photoresist response to 18.2nm laser radiation and transmissivity of 0.1m thick silicion-nitride (Si{sub 3}N{sub 4}) windows were important initial works. The goal of the first year of Phase II was to construct X-ray contact microscope in combination with existing optical phase microscope, already used by biologists. In the second year of Phase II study of dehydrated Horeseshoe Crab and Hela cancer cells were performed with COXRALM. Also during Phase II, the Imaging X-Ray Laser Microscope (IXRALM) was designed and constructed. This paper describes the development of each of the microscopes and their application for research.
fel 2005 :: Free Electron Laser Conference and Workshop
Home | Attendee List | Program | Abstract Submission | Payment | Call for Papers | Exhibitors | Travel 2005 International Free Electron Laser Prize Winner: Avi Gover left to right: John Galayda, Avi Gover (FEL2005 Prize Winner, Alexander Van der Meer This year the FEL Prize Committee awarded the FEL Prize to Avraham (Avi) Gover from Tel-Aviv University for his pioneering work in laying the foundation of FEL theory. Avi Gover, presently head of the FEL Knowledge Center in Israel, has been a member of the FEL community from the very beginning, publishing his first paper on FELs in 1976. In those early years, he played a key role in putting FEL theory on a firm basis by showing the similarities between FELs, 'ordinary' lasers and other free electron radiation devices such as TWTs. In later years he made important contributions to the formulation of a unified theory of superradiant emission in the linear and, more recently, also in the non-linear regime. His deep understanding of the field enabled him to propose conceptually new schemes like stimulated superradiance and post-saturation emission enhancement. In addition to his extensive work and contributions to FEL theory, he also led and contributed to a number of experimental projects aimed at studies of fundamental effects and at the development of new FEL device schemes. Most notably the demonstration of a two-stage BWO FEL and a longitudinal wiggler FEL, demonstration of electron trapping in two counter propagating laser beams and of single-mode locking in a prebunched FEM. He has also been the main driving force behind the international efforts to develop high-average power masers based on electrostatic accelerators in the inverted setup, that is with the undulator at high voltage. Along this line, he also took the initiative for an Israelean FEM user facility and notwithstanding the difficult funding situation in his country, this facility is now operational at the College of Judea and Samaria in Ariel.
Measurements of the LCLS Laser Heater and its impact on the x-ray FEL Performance
The very bright electron beam required for an x-ray free-electron laser (FEL), such as the Linac Coherent Light Source (LCLS), is susceptible to a microbunching instability in the magnetic bunch compressors, prior to the FEL undulator. The uncorrelated electron energy spread in the LCLS can be increased by an order of magnitude to provide strong Landau damping against the instability without degrading the FEL performance. To this end, a 'laser-heater' system has been installed in the LCLS injector, which modulates the energy of a 135-MeV electron bunch with an IR laser beam in a short undulator, enclosed within a four-dipole chicane. In this paper, we report detailed measurements of laser heater-induced energy spread, including the unexpected self-heating phenomenon when the laser energy is very low. We discuss the suppression of the microbunching instability with the laser heater and its impact on the x-ray FEL performance. We also present the analysis of these experimental results and develop a three-dimensional longitudinal space charge model to explain the self-heating effect.
Huang, Zhirong; Brachmann, A.; Decker, F.-J.; Ding, Y.; Dowell, D.; Emma, P.; Frisch, J.; Gilevich, S.; Hays, G.; Hering, Ph.; Iverson, R.; Loos, H.; Miahnahri, A.; Nuhn, H.-D.; Ratner, D.; Stupakov, G.; Turner, J.; Welch, J.; White, W.; Wu, J.; Xiang, D.
XUV free-electron laser-based projection lithography systems
Free-electron laser sources, driven by rf-linear accelerators, have the potential to operate in the extreme ultraviolet (XUV) spectral range with more than sufficient average power for high-volume projection lithography. For XUV wavelengths from 100 nm to 4 nm, such sources will enable the resolution limit of optical projection lithography to be extended from 0.25 {mu}m to 0.05{mu}m and with an adequate total depth of focus (1 to 2 {mu}m). Recent developments of a photoinjector of very bright electron beams, high-precision magnetic undulators, and ring-resonator cavities raise our confidence that FEL operation below 100 nm is ready for prototype demonstration. We address the motivation for an XUV FEL source for commercial microcircuit production and its integration into a lithographic system, include reflecting reduction masks, reflecting XUV projection optics and alignment systems, and surface-imaging photoresists. 52 refs., 7 figs.
Newnam, B.E.
Free-Electron Laser-Powered Electron Paramagnetic Resonance Spectroscopy
Electron paramagnetic resonance (EPR) spectroscopy interrogates unpaired electron spins in solids and liquids to reveal local structure and dynamics; for example, EPR has elucidated parts of the structure of protein complexes that have resisted all other techniques in structural biology. EPR can also probe the interplay of light and electricity in organic solar cells and light-emitting diodes, and the origin of decoherence in condensed matter, which is of fundamental importance to the development of quantum information processors. Like nuclear magnetic resonance (NMR), EPR spectroscopy becomes more powerful at high magnetic fields and frequencies, and with excitation by coherent pulses rather than continuous waves. However, the difficulty of generating sequences of powerful pulses at frequencies above 100 GHz has, until now, confined high-power pulsed EPR to magnetic fields of 3.5 T and below. Here we demonstrate that ~1 kW pulses from a free-electron laser (FEL) can power a pulsed EPR spectrometer at 240 GHz...
Takahashi, S; Edwards, D T; van Tol, J; Ramian, G; Han, S; Sherwin, M S
Radiation from laser accelerated electron bunches: Coherent terahertz and femtosecond X-rays
by an intense ultrashort laser pulse,� Science, vol. 298,generated from intense laser-plasma interactions,� Appl.monochromatic x-rays in the laser synchrotron source
A wide bandwidth free-electron laser with mode locking using current modulation.
A new scheme for mode locking a free-electron laser amplifier is proposed based on electron beam current modulation. It is found that certain properties of the original concept, based on the energy modulation of electrons, are improved including the spectral brightness of the source and the purity of the series of short pulses. Numerical comparisons are made between the new and old schemes and between a mode-locked free-electron laser and self-amplified spontaneous emission free-electron laser. Illustrative examples using a hypothetical mode-locked free-electron laser amplifier are provided. The ability to generate intense coherent radiation with a large bandwidth is demonstrated.
Kur, E.; Dunning, D. J.; McNeil, B. W. J.; Wurtele, J.; Zholents, A. A. (Accelerator Systems Division (APS)); (Univ. of California at Berkeley); (Univ. of Strathclyde); (STFC Daresbury Lab.); (LBNL)
Free Electron Laser Program Program at TJNAF| U.S. DOE Office...
Office of Science (SC) Website
Free Electron Laser Program Program at TJNAF Nuclear Physics (NP) NP Home About Research Facilities Science Highlights Benefits of NP Spinoff Applications Spinoff Archives SBIR...
Performance study of a soft X-ray harmonic generation FEL seeded with an EUV laser pulse
28th International Free Electron Laser Conference (FEL06),26th International Free Electron Laser Conference (FEL04),on the Free Electron Laser Theory and Related Topics, World
Gullans, M.; Wurtele, J.S.; Penn, G.; Zholents, A.A.
Ultraviolet Free Electron Laser Facility preliminary design report
This document, the Preliminary Design Report (PDR) for the Brookhaven Ultraviolet Free Electron Laser (UV FEL) facility, describes all the elements of a facility proposed to meet the needs of a research community which requires ultraviolet sources not currently available as laboratory based lasers. Further, for these experiments, the requisite properties are not extant in either the existing second or upcoming third generation synchrotron light sources. This document is the result of our effort at BNL to identify potential users, determine the requirements of their experiments, and to design a facility which can not only satisfy the existing need, but have adequate flexibility for possible future extensions as need dictates and as evolving technology allows. The PDR is comprised of three volumes. In this, the first volume, background for the development of the proposal is given, including descriptions of the UV FEL facility, and representative examples of the science it was designed to perform. Discussion of the limitations and potential directions for growth are also included. A detailed description of the facility design is then provided, which addresses the accelerator, optical, and experimental systems. Information regarding the conventional construction for the facility is contained in an addendum to volume one (IA).
Ben-Zvi, I. [ed.
LIPSS Free-Electron Laser Searches for Dark Matter
A variety of Dark Matter particle candidates have been hypothesized by physics Beyond the Standard Model (BSM) in the very light (10{sup -6} - 10{sup -3} eV) range. In the past decade several international groups have conducted laboratory experiments designed to either produce such particles or extend the boundaries in parameter space. The LIght Pseudo-scalar and Scalar Search (LIPSS) Collaboration, using the 'Light Shining through a Wall' (LSW) technique, passes the high average power photon beam from Jefferson Lab's Free-Electron Laser through a magnetic field upstream from a mirror and optical beam dump. Light Neutral Bosons (LNBs), generated by coupling of photons with the magnetic field, pass through the mirror ('the Wall') into an identical magnetic field where they revert to detectable photons by the same coupling process. While no evidence of LNBs was evident, new scalar coupling boundaries were established. New constraints were also determined for hypothetical para-photons and for millicharged fermions. We will describe our experimental setup and results for LNBs, para-photons, and milli-charged fermions. Plans for chameleon particle searches are underway.
Afanaciev, Andrei; Beard, Kevin; Biallas, George; Boyce, James R; Minarni, M; Ramdon, R; Robinson, Taylor; Shinn, Michelle D
Beyond the Standard Model Searches Using a Free Electron Laser
Much of the focus of Beyond the Standard Model physics searches is on the TeV scale, making use of hadron and lepton colliders. Additionally, however, there is the means to make these searches in different regions of parameter space using sub-electron volt photons from a Free Electron Laser, for example. We report on the experimental results of searches for optical-wavelength photons mixing with hypothetical hidden-sector paraphotons in the mass range between 10{sup -5} and 10{sup -2} electron volts for a mixing parameter greater than 10{sup -7}. We also report on the results of a sensitive search for scalar coupling of photons to light neutral bosons in the mass range of approximately 1.0 milli-electron volts and coupling strength greater than 10{sup -6} GeV{sup -1}. These were generation-regeneration experiments using the 'light shining through a wall' technique in which regenerated photons are searched for downstream of an optical barrier that separates it from an upstream generation region. The present results indicate no evidence for photon-paraphoton mixing or for scalar couplings of bosons to photons for the range of parameters investigated.
Afanasev, A.; Ramdon, R. [Department of Physics, Hampton University, Hampton, VA 23668 (United States); Baker, O. K.; Slocum, P. [Department of Physics, Yale University, P.O. Box 208120, New Haven, CT 06520 (United States); Beard, K. B. [Muons, Inc., 552 N. Batavia Avenue, Batavia, IL 60510 (United States); Biallas, G.; Boyce, J.; Shinn, M. [Free Electron Laser Division, Jefferson Laboratory, 12000 Jefferson Avenue, Newport News, VA 23606 (United States); Minarni, M. [Department of Physics, Universitas Riau (UNRI), Pekanbaru, Riau 28293 (Indonesia)
Electron bunch energy and phase feed-forward stabilization system for the Mark V RF-linac free-electron laser
An amplitude and phase compensation system has been developed and tested at the University of Hawai'i for the optimization of the RF drive system to the Mark V free-electron laser. Temporal uniformity of the RF drive is essential to the generation of an electron beam suitable for optimal free-electron laser performance and the operation of an inverse Compton scattering x-ray source. The design of the RF measurement and compensation system is described in detail and the results of RF phase compensation are presented. Performance of the free-electron laser was evaluated by comparing the measured effects of phase compensation with the results of a computer simulation. Finally, preliminary results are presented for the effects of amplitude compensation on the performance of the complete system.
Hadmack, M. R.; Kowalczyk, J. M. D.; Lienert, B. R.; Madey, J. M. J.; Szarmes, E. B. [Department of Physics and Astronomy, University of Hawai'i at Manoa, Honolulu, Hawaii 96822 (United States); Jacobson, B. T. [RadiaBeam Technologies, Santa Monica, California 90404 (United States)
An amplitude and phase compensation system has been developed and tested at the University of Hawai`i for the optimization of the RF drive system to the Mark V Free-Electron Laser. Temporal uniformity of the RF drive is essential to the generation of an electron beam suitable for optimal free-electron laser performance and the operation of an inverse Compton scattering x-ray source. The design of the RF measurement and compensation system is described in detail and the results of RF phase compensation are presented. Performance of the free-electron laser was evaluated by comparing the measured effects of phase compensation with the results of a computer simulation. Finally, preliminary results are presented for the effects of amplitude compensation on the performance of the complete system.
Hadmack, M R; Kowalczyk, J M D; Lienert, B R; Madey, J M J; Szarmes, E B
Reversible Electron Beam Heating for Suppression of Microbunching Instabilities at Free-Electron Lasers
The presence of microbunching instabilities due to the compression of high-brightness electron beams at existing and future x-ray free-electron lasers (FELs) results in restrictions on the attainable lasing performance and renders beam imaging with optical transition radiation impossible. The instability can be suppressed by introducing additional energy spread, i.e., heating the electron beam, as demonstrated by the successful operation of the laser heater system at the Linac Coherent Light Source. The increased energy spread is typically tolerable for self-amplified spontaneous emission FELs but limits the effectiveness of advanced FEL schemes such as seeding. In this paper, we present a reversible electron beam heating system based on two transverse deflecting radio-frequency structures (TDSs) upstream and downstream of a magnetic bunch compressor chicane. The additional energy spread is introduced in the first TDS, which suppresses the microbunching instability, and then is eliminated in the second TDS. We show the feasibility of the microbunching gain suppression based on calculations and simulations including the effects of coherent synchrotron radiation. Acceptable electron beam and radio-frequency jitter are identified, and inherent options for diagnostics and on-line monitoring of the electron beam's longitudinal phase space are discussed.
Behrens, Christopher; /DESY; Huang, Zhirong; Xiang, Dao; /SLAC
Multilayers for next generation x-ray sources
Multilayers are artificially layered structures that can be used to create optics and optical elements for a broad range of x-ray wavelengths, or can be optimized for other applications. The development of next generation x-ray sources (synchrotrons and x-ray free electron lasers) requires advances in x-ray optics. Newly developed multilayer-based mirrors and optical elements enabled efficient band-pass filtering, focusing and time resolved measurements in recent FLASH (Free Electron LASer in Hamburg) experiments. These experiments are providing invaluable feedback on the response of the multilayer structures to high intensity, short pulsed x-ray sources. This information is crucial to design optics for future x-ray free electron lasers and to benchmark computer codes that simulate damage processes.
Bajt, S; Chapman, H N; Spiller, E; Hau-Riege, S; Alameda, J; Nelson, A J; Walton, C C; Kjornrattanawanich, B; Aquila, A; Dollar, F; Gullikson, E; Tarrio, C
Part 2: Coherent emission from Free Electron Lasers
0 0 Electron beam-based sources of ultrashort x-ray pulses Alexander Zholents Advanced Photon Source, Argonne National Laborator , Argonne, IL 60439 (September 7, 2010) To be published by World Scientific Publishing Co. in Reviews of Accelerator Science and Technology. y 2 Electron beam-based sources of ultrashort x-ray pulses * Alexander Zholents Argonne National Laboratory, Advanced Photon Source, 9700 South Cass Ave., Argonne, IL 60439 Abstract A review of various methods for generation of ultrashort x-ray pulses using relativistic electron beam from conventional accelerators is presented. Both spontaneous and coherent emission of electrons is considered. Introduction The importance of the time-resolved studies of matter at picosecond (ps),
Magnetism studies using resonant, coherent, x-ray scattering...
10:00am SLAC, Bldg. 137, Room 226 Keoki Seu Seminar: With the advent of free electron lasers there has been interest in using coherent x-rays to probe condensed matter systems....
Lensless Imaging of Magnetic Nanostructures by X-ray Spectro...
F. Schlotter and J. Sthr (SSRL) The unprecedented properties of X-ray free electron lasers (X-FELs) under development world wide will open the door for entirely new classes of...
Science Challenges & Opportunities for an Advanced X-ray Free...
Science Challenges & Opportunities for an Advanced X-ray Free-electron Laser Wednesday, October 2, 2013 - 3:00pm SLAC, Kavli 3rd Floor Conference Room Robert Schoenlein, Lawrence...
Free Electron Laser Program Program at TJNAF| U.S. DOE Office of Science
Free Electron Laser Program Program at Free Electron Laser Program Program at TJNAF Nuclear Physics (NP) NP Home About Research Facilities Science Highlights Benefits of NP Spinoff Applications Spinoff Archives SBIR/STTR Applications of Nuclear Science and Technology Funding Opportunities Nuclear Science Advisory Committee (NSAC) News & Resources Contact Information Nuclear Physics U.S. Department of Energy SC-26/Germantown Building 1000 Independence Ave., SW Washington, DC 20585 P: (301) 903-3613 F: (301) 903-3833 E: email@example.com More Information » Spinoff Archives Free Electron Laser Program Program at TJNAF Print Text Size: A A A RSS Feeds FeedbackShare Page Application/instrumentation: Free Electron Laser (FEL) Program Developed at: Thomas Jefferson National Laboratory Developed in: 1990's - 2010
Proceedings of the workshop prospects for a 1 angstrom free-electron laser
This report contains papers on the following topics free-electron laser theory, scaling relations and simulations; micro-wigglers; photocathode and switched power gun; applications; and summary of working groups.
Gallardo, J.C. (ed.)
Bright High Average Power Table-top Soft X-Ray Lasers
We have demonstrated the generation of bright soft x-ray laser pulses with record-high average power from compact plasma amplifiers excited by ultrafast solid state lasers. These lasers have numerous applications in nanoscience and nanotechnology.
Rocca, Jorge [Colorado State University, Fort Collins; Reagan, Brendon [Colorado State University, Fort Collins; Wernsing, Keith [Colorado State University, Fort Collins; Luther, Brad [Colorado State University, Fort Collins; Curtis, Alden [Colorado State University, Fort Collins; Nichols,, Anthony [Colorado State University, Fort Collins; Wang, Yong [Colorado State University, Fort Collins; Alessi, David [Colorado State University, Fort Collins; Martz, Dale [Colorado State University, Fort Collins; Yin, Liang [Colorado State University, Fort Collins; Wang, Shoujun [Colorado State University, Fort Collins; Berrill, Mark A [ORNL; Furch, Federico [Colorado State University, Fort Collins; Woolston, Mark [Colorado State University, Fort Collins; Patel, Dinesh [Colorado State University, Fort Collins; Marconi, Mario [Colorado State University, Fort Collins; Menoni, Carmen [Colorado State University, Fort Collins
Preparations for a high gradient inverse free electron laser experiment at Brookhaven national laboratory
Preparations for an inverse free electron laser experiment at Brookhaven National Laboratory's Accelerator Test Facilty are presented. Details of the experimental setup including beam and laser transport optics are first discussed. Next, the driving laser pulse structure is investigated and initial diagnostics are explored and compared to simulations. Finally, planned improvements to the experimental setup are discussed.
Duris, J.; Li, R. K.; Musumeci, P.; Sakai, Y.; Threlkeld, E.; Williams, O.; Fedurin, M.; Kusche, K.; Pogorelsky, I.; Polyanskiy, M.; Yakimenko, V. [UCLA Department of Physics and Astronomy, Los Angeles, CA 90095 (United States); Accelerator Test Facility, Brookhaven National Laboratory, Upton, NY, 11973 (United States)
Secretary Chu Dedicates World's Most Powerful X-ray Laser | Department of
Dedicates World's Most Powerful X-ray Laser Dedicates World's Most Powerful X-ray Laser Secretary Chu Dedicates World's Most Powerful X-ray Laser August 16, 2010 - 12:00am Addthis Washington, D.C. - U.S. Energy Secretary Steven Chu today dedicated the Linac Coherent Light Source (LCLS), the world's first and most powerful X-ray laser, at the Department of Energy's SLAC National Accelerator Laboratory. The LCLS will play an essential role in addressing the scientific needs of the 21st century by exploring new ways to create better energy sources and enabling advances in a range of scientific fields. The LCLS produces pulses of X-rays more than a billion times brighter than the most powerful existing sources. The ultrafast X-ray pulses are used much like flashes from a high-speed strobe light, enabling scientists to take
Femtosecond dark-field imaging with an X-ray free electron laser
DOE Data Explorer (OSTI)
This data was collected as part of the same experiment as the data deposited in [ID16](id-16.html). Experiment details are given in [Loh, N.D. et al.](http://dx.doi.org/10.1038/nature11222)
Martin, A. V.
Physical Society, 1996 R&D 100 Award for global feedbackLaboratory, Berkeley, CA R&D Engineer, Lawrence LivermoreLaboratory, Livermore, CA R&D Engineer, Weyerhaeuser
Staples, John
Radiation from the Brookhaven Vacuum-Ultraviolet ElectronArgonne National Laboratory, Brookhaven National Laboratory,Physicist Physics Department Brookhaven National Laboratory
Femtosecond diffractive imaging with a soft-X-ray free-electron laser
The diffraction pattern of this entry corresponds to the one shown in **figure 2a** of the corresponding citation.
Chapman, H. N.
elements, Jan 2000 Invention Disclosure Compact, tunable,field multipole, May 1997 Invention Disclosure Tunable pure
S.H. Kim, D. Mangra, ORNL-SNS; D. Barni, C. Pagani, P.for the Spallation Neutron Source (SNS) project,� 50. StuartSpallation Neutron Source (SNS) cavities operate. This may
Radiation Lightsource (SSRL), Photon Science (PS), andRadiation Laboratory (SSRL) Member of the editorial board ofradiation user facilities SSRL (based on SPEAR3, a third-
P. Innocenzi, IKNO, a user facility for coherent terahertzAn ultimate experimental user facility will bring additionalgun has to operate in a user facility . Table 2.1 summarizes
A 429, 243 (1999). [18] LCLS Design Study Group, ReportLinac Coherent Light Source (LCLS) [18], except the electron
Design Studies for a VUV--Soft X-ray Free-Electron Laser Array
bunch arrival time in the LCLS, and another system that willFERMI@Elettra and 100 fs for LCLS, both requiring about 200-
Corlett, J.
2007). 41. P. Emma for the LCLS commissioning team, PAC2009Test Facility for the LCLS�, SLAC-TN-07-005, (2007). John N.Professional/Academic Director, LCLS Strategic Projects
Using the X-FEL to photo-pump X-ray laser transitions in He-like Ne
Nearly four decades ago H-like and He-like resonantly photo-pumped laser schemes were proposed for producing X-ray lasers. However, demonstrating these schemes in the laboratory has proved to be elusive because of the difficulty of finding a strong resonant pump line. With the advent of the X-ray free electron laser (X-FEL) at the SLAC Linac Coherent Light Source (LCLS) we now have a tunable X-ray laser source that can be used to replace the pump line in previously proposed laser schemes and allow researchers to study the physics and feasibility of resonantly photo-pumped laser schemes. In this paper we use the X-FEL at 1174 eV to photo-pump the singly excited 1s2p state of He-like Ne to the doubly excited 2p3p state and model gain on the 2p3p-2p2s transition at 175 eV and the 2p3p-1s3p transition at 1017 eV. One motivation for studying this scheme is to explore possible quenching of the gain due to strong non-linear coupling effects from the intense X-FEL beam We compare this scheme with photo-pumping the He-like Ne ground state to the 1s3p singly excited state followed by lasing on the 3p-2s and 3d-2p transitions at 158 and 151 eV. Experiments are being planned at LCLS to study these laser processes and coherent quantum effects.
Nilsen, J; Rohringer, N
Interaction of a high intensity laser with matter may generate an ionizing radiation hazard. Very limited studies have been made, however, on the laser-induced radiation protection issue. This work reviews available literature on the physics and characteristics of laser-induced X-ray hazards. Important aspects include the laser-to-electron energy conversion efficiency, electron angular distribution, electron energy spectrum and effective temperature, and bremsstrahlung production of X-rays in the target. The possible X-ray dose rates for several femtosecond Ti:sapphire laser systems used at SLAC, including the short pulse laser system for the Matter in Extreme Conditions Instrument (peak power 4 TW and peak intensity 2.4 x 10{sup 18} W/cm{sup 2}) were analysed. A graded approach to mitigate the laser-induced X-ray hazard with a combination of engineered and administrative controls is also proposed.
Qiu, Rui
Method and apparatus for producing durationally short ultraviolet or X-ray laser pulses
A method and apparatus is disclosed for producing ultraviolet or X-ray laser pulses of short duration (32). An ultraviolet or X-ray laser pulse of long duration (12) is progressively refracted, across the surface of an opaque barrier (28), by a streaming plasma (22) that is produced by illuminating a solid target (16, 18) with a pulse of conventional line focused high power laser radiation (20). The short pulse of ultraviolet or X-ray laser radiation (32), which may be amplified to high power (40, 42), is separated out by passage through a slit aperture (30) in the opaque barrier (28).
MacGowan, Brian J. (Livermore, CA); Matthews, Dennis L. (El Granada, CA); Trebes, James E. (Livermore, CA)
. The output of power inverter is connected to input coil of isolated power transformer (300kV). Timer Electric power for part 2 goes from power inverter through isolated power transformer (isolation voltageTHE SYSTEM OF POWER SUPPLIES, CONTROL AND MODULATION OF ELECTRON GUN FOR FREE ELECTRON LASER E
The �SF� System of Sextupoles for the JLAB 10 KW Free Electron Laser Upgrade
The characteristics of the system of �SF� Sextupoles for the infrared Free Electron Laser Upgrade1 at the Thomas Jefferson National Accelerator Facility (JLab) are described. These eleven sextupoles possess a large field integral (2.15 T/m) with +/- 0.2%
George Biallas, Mark Augustine, Kenneth Baggett, David Douglas, Robin Wines
Lab Breakthrough: X-ray Laser Captures Atoms and Molecules in Action |
X-ray Laser Captures Atoms and Molecules in X-ray Laser Captures Atoms and Molecules in Action Lab Breakthrough: X-ray Laser Captures Atoms and Molecules in Action July 18, 2012 - 12:51pm Addthis The Linac Coherent Light Source at SLAC is the world's most powerful X-ray laser, which helps researchers understand the extreme conditions found in the hearts of stars and giant planets guiding research into nuclear fusion, the mechanism that powers the sun. View the entire Lab Breakthrough playlist. Michael Hess Michael Hess Former Digital Communications Specialist, Office of Public Affairs How is the LCLS different? Rather than accelerate particles to collide them, it accelerates particles in a special way to create extremely bright bunches of photons. These pulses are about 10 billion times brighter and one thousand
Inner-Shell Photon-Ionized X-Ray Laser at 45(Angstrom)
This report summarizes the major accomplishments of this three-year Laboratory Directed Research and Development (LDRD) Lab Wide (LW) project entitled, ''An Inner-Shell Photo-Ionized X-Ray Laser at 45 {angstrom}'', tracking code 99-LW-042. The most significant accomplishments of this project include the design of a suitable x-ray laser target, the invention of a measurement technique for the determination of rise times of x-ray pulses on the order of 50 femtoseconds, and a novel setup for generating a traveling wave with an ultrashort optical laser pulse. The pump probe technique for rise time measurement will allow us to detect ultrashort x-ray pulses, whose generation by means of a variety of 4th generation light sources is currently under planning elsewhere.
Weber, F; Celliers, P; Moon, S; Snavely, R; Da Silva, L
Photoionization-pumped, Ne II, x-ray laser studies project. Final report
The energetics of this pumping scheme are shown. Short-pulse (50 to 100 ps) laser irradiation of an appropriate x-ray flashlamp medium generates broad-band emission in the range of 300 to 800 eV which preferentially photoionizes Ne to the /sup 2/S state of Ne II creating an inversion at approximately 27 eV. Although this approach does not depend on precise spectral overlap between the x-ray pump radiation and the medium to be pumped, it does require that the x-ray medium remain un-ionized prior to photoionization by the soft x-ray emission. Well-controlled focus conditions are required to ensure that the x-ray medium is not subjected to electron or x-ray preheat prior to irradiation by the soft x-ray source. The magnitude of the population inversion is predicted to be critically dependent upon rapid photoionization of the two states; therefore, ultra-short pulse irradiation of the laser flashlamps is required.
Richardson, M.C.; Hagelstein, P.L.; Eckart, M.J.; Forsyth, J.M.; Gerrassimenko, M.; Soures, J.M.
Shielding Calculations for the Hard X-Rays Generated by LCLS Mec Laser System
Linac Coherent Light Source (LCLS) Matter in Extreme Conditions (MEC) Instrument is an X-ray instrument that will be able to create and diagnose High Energy Density (HED) matter. The MEC laser system can generate hard X-ray due to the interaction of the laser and the plasma. This paper summarizes results of the shielding calculations performed to evaluate the radiation hazards induced by this hard X-ray source with Monte Carlo code FLUKA. The dose rates and photon spectra due to this X-ray source are calculated at different locations with different shielding. The influence of the electron temperature on the source terms and the shielding effectiveness was also investigated.
Not Available
Chorus wave amplification: A free electron laser in the Earth's magnetosphere
A new theoretical model for whistler-mode chorus amplification in the Earth's magnetosphere is presented. We derive, based on the free-electron laser mechanism in a high-gain amplifier, a new closed set of self-consistent relativistic equations that couple the Hamiltonian equations for particles with Maxwell's equations. We demonstrate that these equations predict, through a cubic equation, whistler amplification levels in good agreement with those observed in the Earth's magnetosphere.
Soto-Chavez, A. R.; Bhattacharjee, A. [Space Science Center, University of New Hampshire, Durham, New Hampshire 03824 (United States); Ng, C. S. [Geophysical Institute, University of Alaska Fairbanks, Fairbanks, Alaska 99775 (United States)
High harmonic attosecond pulse train amplification in a free electron laser
It is shown using three-dimensional simulations that the temporal structure of an attosecond pulse train, such as that generated via high harmonic generation in noble gases, may be retained in a free electron laser amplifier through to saturation using a mode-locked optical klystron configuration. At wavelengths of {approx}12 nm, a train of attosecond pulses of widths {approx}300 as with peak powers in excess of 1 GW are predicted.
McNeil, B.W.; Sheehy, B.; Thompson, N.R.; Dunning, D.J.
Hydrogen-like recombination x-ray laser experiments using a 20 picosecond laser pulse at the Nova facility
Hydrogen-like recombination X-ray lasers are currently under investigation as an alternative candidate to collisional pumped soft X-ray amplifiers. Efforts are being concentrated on the n = 3 to n = 2 transitions in H-like Mg and NaF. 5 refs., 1 fig.
Shephard, R.; Fields, D.; DaSilva, L.; Keane, C.; MacGowen, B.; Matthews, D.; Shimkaveg, G.; Stone, G.; Eder, D.; Osterheld, A.; Walling, R.; Young, B.K.F.; Fry, A.; Eckart, M.; Goldstein, W.; Stewart, R. (Lawrence Livermore National Lab., CA (USA)); Charatis, G.; Busch, G. (KMS Fusion, Inc., Ann Arbor, MI (USA))
In this project, we proposed to develop laser based mid-infrared lasers as a potentially robust and reliable source of ultrafast pulses in the mid-infrared region of the spectrum, and to apply this light source to generating bright, coherent, femtosecond-to-attosecond x-ray beams.
Sterling Backus
Development of an XUV-IR free-electron laser user facility for scientific research and industrial applications
Los Alamos has designed and proposes to establish an XUV-IR free- electron laser (FEL) user facility for scientific research and industrial applications based on coherent radiation ranging from soft x-rays as short as 1 nm to far-infrared wavelengths as long as 100 {mu}m. As the next-generation light source beyond low-emittance storage rings with undulator insertion devices, this proposed national FEL user facility should make available to researchers broadly tunable, picosecond-pulse, coherent radiation with 10{sup 4} to 10{sup 7} greater spectral flux and brightness. The facility design is based on two series of FEL oscillators including one regenerative amplifier. The primary series of seven FEL oscillators, driven by a single, 1-GeV rf linac, spans the short-wavelength range from 1 to 600 nm. A second 60-MeV rf linac, synchronized with the first, drives a series of three Vis/IR FEL oscillators to cover the 0. 5 to 100-{mu}m range. This paper presents the motivation for such a facility arising from its inherently high power per unit bandwidth and its potential use for an array of scientific and industrial applications, describes the facility design, output parameters, and user laboratories, makes comparisons with synchrotron radiation sources, and summarizes recent technical progress that supports the technical feasibility. 80 refs., 9 figs., 6 tabs.
Newnam, B.E.; Warren, R.W.; Conradson, S.D.; Goldstein, J.C.; McVey, B.D.; Schmitt, M.J.; Elliott, C.J.; Burns, M.J.; Carlsten, B.E.; Chan, K.C.; Johnson, W.J.; Wang, T.S.; Sheffield, R.L.; Meier, K.L.; Olsher, R.H.; Scott, M.L.; Griggs, J.E.
Analysis of saturation phenomena in Cerenkov free-electron lasers with a planar waveguide
In this paper, the operation of the stimulated emission in Cerenkov free-electron laser (CFEL) is studied on the basis of the modulations of electron velocity and density by the electromagnetic (EM) field. The influence of the electron relaxation, due to mutual electrons collisions, on the electron dynamics is taken into account. We investigate the growth characteristics of Cerenkov laser operating in the small-signal and saturation regimes. In the saturation regime, the effect of velocity reduction of the electron beam on the gain dynamics is demonstrated. We also show that our results match with those of other well-known treatments in the small-signal gain limit.
Fares, Hesham; Yamada, Minoru [Division of Electrical Engineering and Computer Science, Kanazawa University, Kakuma-machi, Kanazawa, Ishikawa 920-1192 (Japan)
Overview of the program on soft x-ray lasers and their applications at Princeton
In the last several years, rapid progress in the development of soft x-ray lasers (SXL) has been observed at a number of laboratories worldwide. Although SXLs are very young'' devices they have already been used for microscopy and holography, and new ideas emerging for broader application of SXLs to microscopy, holography and lithography. This paper describes the work at Princeton University on the development of a soft x-ray imaging transmission microscopy using a SXL as a radiation source and work on the development of a novel soft x-ray reflection microscope and its application to biological cell studies and lithography. Progress in the development of a photopumped VUV laser (60 nm), and programs for the development of a small scale SXL and for the application of a powerful subpicosecond KrF laser system are also discussed. 35 refs., 9 figs., 1 tab.
Suckewer, S.; Ilcisin, K. (Princeton Univ., NJ (USA). Plasma Physics Lab. Princeton Univ., NJ (USA). Dept. of Mechanical and Aerospace Engineering)
A bright point source of ultrashort hard x-rays from laser bioplasmas
Micro and nano structures scatter light and amplify local electric fields very effectively. Energy incident as intense ultrashort laser pulses can be converted to x-rays and hot electrons more efficiently with a substrate that suitably modifies the local fields. Here we demonstrate that coating a plain glass surface with a few micron thick layer of an ubiquitous microbe, {\\it Escherichia coli}, catapults the brightness of hard x-ray bremsstrahlung emission (up to 300 keV) by more than two orders of magnitude at an incident laser intensity of 10$^{16}$ W cm$^{-2}$. This increased yield is attributed to the local enhancement of electric fields around individual {\\it E. coli} cells and is reproduced by detailed particle-in-cell (PIC) simulations. This combination of laser plasmas and biological targets can lead to turnkey, multi-kilohertz and environmentally safe sources of hard x-rays.
Krishnamurthy, M; Lad, Amit D; Ahmad, Saima; Narayanan, V; Rajeev, R; Kundu, M; Kumar, G Ravindra; Ray, Krishanu
Bendable Focusing X-Ray Optics for the ALS and the LCLS/FEL: Design, Metrology, and Performance
Optics for the ALS and the LCLS/FEL: Design, Metrology, andwas performed in support of the AMO/LCLS project at SLAC. *Coherent Light Source (LCLS) x-ray free electron laser (FEL)
Yashchuk, V. V.
SLAC National Accelerator Laboratory - X-ray Laser Explores How...
How to Write Data with Light By Glenn Roberts Jr. March 19, 2013 Using laser light to read and write magnetic data by quickly flipping tiny magnetic domains could help keep pace...
Threshold conditions for lasing of a free electron laser oscillator with longitudinal electrostatic wiggler
The system of the nonlinear non-stationary equations describing spatial-temporal dynamics of the amplitudes of an ondulator radiation and a space-charge wave of a relativistic electron beam in the resonator is obtained. A free electron laser resonator with longitudinal electrostatic wiggler is considered. In the linear approximation, the threshold conditions of lasing for Raman and Compton regimes under excitation of forward and backward electromagnetic wave are achieved. In the various physical situations, the variation of the minimum length of the resonator with the amplitude of wiggler, density of electron beam, and with the reflection coefficients of resonator's mirrors is investigated.
Sepehri Javan, N. [Department of Physics, Faculty of Sciences, University of Mohaghegh Ardabili, P.O. Box 179, Ardabil, 56199-11367 (Iran, Islamic Republic of)
X-ray line broadening as a compression diagnostic for laser-induced implosions
It is suggested that the best way to measure maximum compressions in laser-induced implosion experiments may be to measure the line profiles of x-ray lines due to impurities in the compressed material. The experimental difficulties in making such measurements and the theoretical problems of interpreting these measurements are discussed.
Chapline, G.F.; DeWitt, H.E.; Hooper, C.F. Jr.
Single mimivirus particles intercepted and imaged with an X-ray laser
These are the files used to reconstruct the images in the paper "Single Mimivirus particles intercepted and imaged with an X-ray laser". Besides the diffracted intensities, the Hawk configuration files used for the reconstructions are also provided. The files from CXIDB ID 1 are the pattern and configuration files for the pattern showed in Figure 2a in the paper.
Seibert, M. Marvin; Ekeberg, Tomas; Maia, Filipe R.N.C.
These are the files used to reconstruct the images in the paper "Single Mimivirus particles intercepted and imaged with an X-ray laser". Besides the diffracted intensities, the Hawk configuration files used for the reconstructions are also provided. The files from CXIDB ID 2 are the pattern and configuration files for the pattern showed in Figure 2b in the paper.
Seibert, M. Marvin; Ekeberg, Tomas
High gain x-ray lasers pumped by transient collisional excitation
We present recent results of x-ray laser amplification of spontaneous emission in Ne-like and Ni-like transient collisional excitation schemes. The plasma formation, ionization and collisional excitation can be optimized using two laser pulses of 1 ns and 1 ps duration at table-top energies of 5 J in each beam. High gain of 35 cm{sup -1} has been measured on the 147 {Angstrom} 4d{r_arrow}4p J=0{r_arrow}1 transition of Ni-like Pd and is a direct consequence of the nonstationary population inversion produced by the high intensity picosecond pulse. We report the dependence of the x-ray laser line intensity on the laser plasma conditions and compare the experimental measurements with hydrodynamic and atomic kinetics simulations for Ne-like and Ni-like lasing.
Dunn, J., LLNL
Applications and source development for high-repetition rate x-ray lasers
Many applications in material science, chemistry, and atomic physics require an x-ray source that has a repetition rate of 1 Hz to a few kHz. In these fields, a very wide range of photon energies is of interest. One application is time-resolved surface photoelectron spectroscopy and microscopy where low energy (energies below 100 eV are very good with higher energy capabilities expected in the future. In addition, prospects of table-top size x-ray lasers with kHz repetition rates are presented.
Eder, D.C.; Amendt, P.; Bolton, P.R. [and others
Uv Thomson scattering from x-ray laser plasmas
Plasmas produced by irradiating massive carbon targets with a 1.064 {mu}m, 1.5 ns laser pulse at incident energies of {approximately}100 J have been investigated. UV thermal Thomson scattering was used to obtain the electron and ion temperatures, as well as drift velocities. The electron density was obtained by optical interferometry. The results are compared to hydrodynamic computer modeling. 6 refs., 6 figs.
La Fontaine, B.; Baldis, H.A.; Villeneuve, D.M.; Bernard, J.E.; Enright, G.D. (National Research Council of Canada, Ottawa, ON (Canada)); Rosen, M.D.; Young, P.E.; Matthews, D.L. (Lawrence Livermore National Lab., CA (USA))
Photopumped x-ray laser research on Saturn
Using Saturn as a driver, we are pursuing both photoresonantly pumped and photoionization/recombination lasers. Our lasing targets are gas cells with thin windows that are pumped by a z pinch 2 cm away radiating 10 TW. In both schemes the lasant and gas fill is neon. We will present evidence for inversion in the sodium/neon photoresonant scheme but we have yet to detect the lasing transition itself. To increase our chances of measuring this line we have introduced potassium into a sodium z-pinch and have eliminated oxygen from the gas cell windows. We have measured the spatial dependence of ionization balance across the gas cell, and this measurement is consistent with propagation of a shock front across the gas cell target. We have measured the Li-like neon 5f-3d transition to increase more rapidly with fill pressure than all other measured lines. Based on this result we have performed experiments emphasizing the photoionization/recombination laser scheme that use a flat-field grazing incidence spectrometer to provide good spatial resolution of the 4f-3d, 4d-3p, and 5f-3d lines of Li-like neon. We have attempted a gain length measurement by imaging parallel to a baffle that varies the length of the target illuminated.
Nash, T.J.; Spielman, R.B.; Vargas, M.; Ruggles, L.
Resonantly photo-pumped nickel-like erbium x-ray laser
A resonantly photo-pumped x-ray laser (10) that enhances the gain of several laser lines that also lase because of collisional excitations and recombination processes, is described. The laser comprises an aluminum (12) and erbium (14) foil combination (16) that is driven by two beams (18, 20) of intense line focused (22, 24) optical laser radiation. Ground state nickel-like erbium ions (34) are resonantly photo-pumped by line emission from hydrogen-like aluminum ions (32). 3 figs., 1 tab.
Analysis of neon soft x-ray spectra from short-pulse laser-produced plasmas
We report preliminary results from the analysis of streaked soft x-ray neon spectra obtained from the interaction of a picosecond Nd:glass laser with a gas jet target. In these experiments streaked spectra show prompt harmonic emission followed by longer time duration soft x-ray line emission. The majority of the line emission observed was found to originate from Li- and Be-like Ne and the major transitions in the observed spectra have been identified. Li-like emission lines were observed to decay faster in time than Be-like transitions, suggesting that recombination is taking place. Line ratios of n=4-2 and n=3-2 transitions supported the view that these lines were optically thin and thick, respectively. The time history of Li-like Ne 2p-4d and 2p-3d lines is in good agreement with a simple adiabatic expansion model coupled to a time dependent collisional-radiative code. Further x-ray spectroscopic analysis is underway which is aimed at diagnosing plasma conditions and assessing the potential of this recombining neon plasma as a quasi-steady-state recombination x-ray laser medium.
Abare, A.C. [Florida Univ., Gainesville, FL (United States); Keane, C.J.; Crane, J.K.; DaSilva, L.B.; Lee, R.W.; Perry, M.D. [Lawrence Livermore National Lab., CA (United States); Falcone, R.W. [California Univ., Berkeley, CA (United States). Dept. of Physics
Lensless X-Ray Imaging in Reflection
Lensless X-Ray Imaging in Lensless X-Ray Imaging in Reflection Lensless X-Ray Imaging in Reflection Print Wednesday, 26 October 2011 00:00 The advent of x-ray free-electron laser (XFEL) light sources has led to an outburst of research activities in the field of lensless imaging. XFELs combine the advantages of sychrotron light sources (high brightness and x-ray wavelengths relevant to atomic and molecular phenomena) with the advantages of visible-light lasers (highly coherent beams). All of these characteristics are important for coherent x-ray diffraction imaging-lensless imaging techniques that are proving to be integral to single-shot, high-resolution imaging of both complex materials and biological samples. Existing techniques are typically designed for transmission geometry, however, and use isolated objects, requiring special sample fabrication and restricting the type of samples under investigation. Recently, researchers from the ALS and the University of Oregon have shown at ALS Beamline 12.0.2 that it is possible to form x-ray holograms in reflection geometry by using the light scattered from a sample, opening the door to lensless imaging of a wealth of new material samples.
X-ray microscopy of laser fusion targets in four energy bands from 0.7 to 4.0 keV
A grazing x-ray microscope was shown to be able to photograph the x-ray emission from laser-produced plasmas between 0.8 and 4.0 keV with a spatial resolution of approximately 3 microns. The calibration of the x-ray mirror energy response functions and the x-ray film allow absolute measurements of the spatial and spectral distribution of the x-ray emission from laser fusion targets. (MOW)
Boyle, M.J.; Seward, F.D.; Harper, T.L.; Koppel, L.N.; Pettipiece, K.J.; Ahlstrom, H.G.
OF AN XUV FEL DRIVEN BY THE LASER-PLASMA ACCELERATOR AT THEFree-electron laser driven bythe LBNL laser-plasma accelerator C. B. Schroeder ? , W. M.
Physically transparent formulation of a free-electron laser in the linear gain regime
The recent 2-dimensional analytic theories of a free-electron laser (FEL) in the linear regime are reformulated in terms of three dimensionless ratios that describe the degree to which the characteristics of the electron beam deviate from the cold beam limit of a beam with no emittance or energy spread. In terms of these ratios, algebraic model equations of a fit that combines features of both of the 2-dimensional analyses are given as a convenient computational tool. Graphs of the FEL gain eigenvalue computed with the combined 2-D formulation illustrate that the gain and the output power at saturation are reduced from the 1-D value, when any of the ratios is larger than unity.
Barletta, W.A. [Lawrence Livermore National Lab., CA (United States); Sessler, A.M. [Lawrence Berkeley Lab., CA (United States); Yu, L.H. [Brookhaven National Lab., Upton, NY (United States)
Chaos in an ion-channel free-electron laser with realistic helical wiggler
Chaotic behavior of an electron motion in a free-electron laser with realistic helical wiggler and ion-channel guiding is studied using Poincare surface-of-section maps. The effects of a realistic electron beam density on chaotic electron dynamics are investigated by considering an electron beam with Gaussian density profile in radial distance. The effects of self-fields on chaotic electron dynamics are investigated for different Gaussian beam parameters, and the results are compared with those of uniform electron beam. It is shown that the electron chaotic behavior can be controlled by changing the Gaussian beam parameter. Also, the chaotic behavior can be controlled by increasing the ion-channel and/or the electron beam densities.
Esmaeilzadeh, Mahdi [Department of Physics, Iran University of Science and Technology, Narmak, Tehran 16844 (Iran, Islamic Republic of); Taghavi, Amin [Department of Applied Science, Qaemshahr Branch, Islamic Azad University, Qaemshahr (Iran, Islamic Republic of)
Acceleration of electrons using an inverse free electron laser auto- accelerator
We present data from our study of a device known as the inverse free electron laser. First, numerical simulations were performed to optimize the design parameters for an experiment that accelerates electrons in the presence of an undulator by stimulated absorption of radiation. The Columbia free electron laser (FEL) was configured as an auto-accelerator (IFELA) system; high power (MW`s) FEL radiation at {approximately}1.65 mm is developed along the first section of an undulator inside a quasi-optical resonator. The electron beam then traverses a second section of undulator where a fraction of the electrons is accelerated by stimulated absorption of the 1.65 mm wavelength power developed in the first undulator section. The second undulator section has very low gain and does not generate power on its own. We have found that as much as 60% of the power generated in the first section can be absorbed in the second section, providing that the initial electron energy is chosen correctly with respect to the parameters chosen for the first and second undulators. An electron momentum spectrometer is used to monitor the distribution of electron energies as the electrons exit the IFELA. We have found; using our experimental parameters, that roughly 10% of the electrons are accelerated to energies as high as 1100 keV, in accordance with predictions from the numerical model. The appearance of high energy electrons is correlated with the abrupt absorption of millimeter power. The autoaccelerator configuration is used because there is no intense source of coherent power at the 1.65 mm design wavelength other than the FEL.
Wernick, I.K.; Marshall, T.C.
We present data from our study of a device known as the inverse free electron laser. First, numerical simulations were performed to optimize the design parameters for an experiment that accelerates electrons in the presence of an undulator by stimulated absorption of radiation. The Columbia free electron laser (FEL) was configured as an auto-accelerator (IFELA) system; high power (MW's) FEL radiation at {approximately}1.65 mm is developed along the first section of an undulator inside a quasi-optical resonator. The electron beam then traverses a second section of undulator where a fraction of the electrons is accelerated by stimulated absorption of the 1.65 mm wavelength power developed in the first undulator section. The second undulator section has very low gain and does not generate power on its own. We have found that as much as 60% of the power generated in the first section can be absorbed in the second section, providing that the initial electron energy is chosen correctly with respect to the parameters chosen for the first and second undulators. An electron momentum spectrometer is used to monitor the distribution of electron energies as the electrons exit the IFELA. We have found; using our experimental parameters, that roughly 10% of the electrons are accelerated to energies as high as 1100 keV, in accordance with predictions from the numerical model. The appearance of high energy electrons is correlated with the abrupt absorption of millimeter power. The autoaccelerator configuration is used because there is no intense source of coherent power at the 1.65 mm design wavelength other than the FEL.
Time Integrated Soft X-ray Imaging in High Intensity Laser Experiments (thesis)
2009 marks a significant achievement and the dawn of a new era in high intensity laser research with the final commissioning of all 192 beams at the National Ignition Facility (NIF). NIF is a department of energy (DOE) funded project more than 10 years in the making located at the Lawrence Livermore National Laboratory (LLNL). The following research was done as one of many preliminary experiments done to prepare for these historic events. The primary focus of the experimental campaign this paper addresses is to test and develop a thermal x-radiation source using a short pulse laser. This data is hoped to provide information about the thermal transport mechanisms important in the development of prediction models in High Energy Density (HED) science. One of several diagnostics fielded was a soft x-ray imager (SXRI) which is detailed in this paper. The SXRI will be used to measure the relative size of the heated region and also the relative level of specific x-ray emissions among several shot and target configurations. The laser system used was the Titan laser located in the Jupiter Laser Facility (JLF) at Lawrence Livermore National Laboratory (LLNL). Titan uses the JLF Janus Nd:glass laser west frontend system with a Optical Parametric Chirped Pulse Amplification (OPCPA) in place of the nanosecond oscillator. The system is capable of producing laser intensities of over a petawatt with several tens of joules delivered in the beam.
Stafford, D
Frontiers in X-Ray Science
The year 2010 marked the fiftieth anniversary of the optical laser and the first anniversary of the world's first hard x-ray free-electron laser, the Linac Coherent Light Source (LCLS) at SLAC. This exciting, new accelerator-based source of x-rays provides peak brilliances roughly a billion times greater than currently available from synchrotron sources such as the Advanced Photon Source at Argonne, and thus explores a qualitatively different parameter space. This talk will describe the first experiments at the LCLS aimed at understanding the nature of high intensity x-ray interactions, related applications in ultrafast imaging on the atomic scale and sketch nascent plans for the extension of both linac and storage-ring based photon sources.
Linda Young
Phase-matched generation of coherent soft and hard X-rays using IR lasers
Phase-matched high-order harmonic generation of soft and hard X-rays is accomplished using infrared driving lasers in a high-pressure non-linear medium. The pressure of the non-linear medium is increased to multi-atmospheres and a mid-IR (or higher) laser device provides the driving pulse. Based on this scaling, also a general method for global optimization of the flux of phase-matched high-order harmonic generation at a desired wavelength is designed.
Popmintchev, Tenio V.; Chen, Ming-Chang; Bahabad, Alon; Murnane, Margaret M.; Kapteyn, Henry C.
Ultraviolet free-electron laser (uv FEL) facility at Brookhaven National Laboratory
DOE Green Energy (OSTI)
The proposal for a Ultraviolet Free-Electron Laser Facility UV-FEL grew from the realization that neither existing lasers or synchrotrons, nor the third generation synchrotron radiation sources now under construction address all of the needs of scientists interested in the ultraviolet region of the spectrum, particularly with respect to the combination of continuous wavelength selection, high peak power and short pulse duration. Several workshops have been held at BNL and elsewhere which explored applications and source requirements in the 5 to 30 eV range. A critical requirement determined was is for very high peak power and short wavelength, especially for applications in chemical physics and non-linear optics. The need for wavelength tuning with the ease and agility to which synchrotron radiation users have become accustomed has also been strongly emphasized. With these initial parameters in mind, the accelerator physics staff set about devising ways to produce this radiation. Their design is for an FEL that has unique characteristics both in terms of possible applications, and in the range of radiation it could produce. In addition, the proposed location of the UV-FEL adjacent to the NSLS means that pump-probe experiments involving radiation from both sources will be possible. Each successive design has been reviewed in consultation with potential users in an iterative process to arrive at the present proposal design.
Johnson, E.D.; Sutherland, J.C.
Resonant Auger Effect at High X-Ray Intensity
The resonant Auger effect of atomic neon exposed to high-intensity x-ray radiation in resonance with the 1s {yields} 3p transition is discussed. High intensity here means that the x-ray peak intensity is sufficient ({approx} 10{sup 18} W/cm{sup 2}) to induce Rabi oscillations between the neon ground state and the 1s{sup -1}3p ({sup 1}P) state within the relaxation lifetime of the inner-shell vacancy. For the numerical analysis presented, an effective two-level model, including a description of the resonant Auger decay process, is employed. Both coherent and chaotic x-ray pulses are treated. The latter are used to simulate radiation from x-ray free-electron lasers based on the principle of self-amplified spontaneous emission. Observing x-ray-driven atomic population dynamics in the time domain is challenging for chaotic pulse ensembles. A more practical option for experiments using x-ray free-electron lasers is to measure the line profiles in the kinetic energy distribution of the resonant Auger electron. This provides information on both atomic population dynamics and x-ray pulse properties.
Rohringer, N; Santra, R
X-Ray Imaging in Reflection Print X-Ray Imaging in Reflection Print The advent of x-ray free-electron laser (XFEL) light sources has led to an outburst of research activities in the field of lensless imaging. XFELs combine the advantages of sychrotron light sources (high brightness and x-ray wavelengths relevant to atomic and molecular phenomena) with the advantages of visible-light lasers (highly coherent beams). All of these characteristics are important for coherent x-ray diffraction imaging-lensless imaging techniques that are proving to be integral to single-shot, high-resolution imaging of both complex materials and biological samples. Existing techniques are typically designed for transmission geometry, however, and use isolated objects, requiring special sample fabrication and restricting the type of samples under investigation. Recently, researchers from the ALS and the University of Oregon have shown at ALS Beamline 12.0.2 that it is possible to form x-ray holograms in reflection geometry by using the light scattered from a sample, opening the door to lensless imaging of a wealth of new material samples.
Lensless X-Ray Imaging in Reflection Print Lensless X-Ray Imaging in Reflection Print The advent of x-ray free-electron laser (XFEL) light sources has led to an outburst of research activities in the field of lensless imaging. XFELs combine the advantages of sychrotron light sources (high brightness and x-ray wavelengths relevant to atomic and molecular phenomena) with the advantages of visible-light lasers (highly coherent beams). All of these characteristics are important for coherent x-ray diffraction imaging-lensless imaging techniques that are proving to be integral to single-shot, high-resolution imaging of both complex materials and biological samples. Existing techniques are typically designed for transmission geometry, however, and use isolated objects, requiring special sample fabrication and restricting the type of samples under investigation. Recently, researchers from the ALS and the University of Oregon have shown at ALS Beamline 12.0.2 that it is possible to form x-ray holograms in reflection geometry by using the light scattered from a sample, opening the door to lensless imaging of a wealth of new material samples.
Generation of strongly coupled Xe cluster nanoplasmas by low intensive soft x-ray laser irradiation
A seeding gas jet including Xe clusters was irradiated with a laser-driven plasma soft x-ray laser pulse ({lambda}=13.9 nm, {approx}7 ps, {<=}5 Multiplication-Sign 10{sup 9} W/cm{sup 2}), where the laser photon energy is high enough to ionize 4d core electrons. In order to clarify how the innershell ionization followed by the Auger electron emission is affected under the intense laser irradiation, the electron energy distribution was measured. Photoelectron spectra showed that the peak position attributed to 4d hole shifted to lower energy and the spectral width was broadened with increasing cluster size. Moreover, the energy distribution exhibited that a strongly coupled cluster nanoplasma with several eV was generated.
Namba, S.; Hasegawa, N.; Kishimoto, M.; Nishikino, M.; Kawachi, T. [Graduate School of Engineering, Hiroshima University,Kagamiyama 1-4-1, Higashi-Hiroshima, Hiroshima, 739-8527 (Japan); Quantum Beam Science Directorate, Japan Atomic Energy Agency, Umemidai 8-1, Kizugawa, Kyoto, 619-0215 (Japan)
Investigation of the electron trajectories and gain regimes of the whistler pumped free-electron laser
A free-electron laser (FEL) scheme, which employs the whistler wave as a slow electromagnetic wave wiggler, was studied theoretically. Subjected to the transverse fields of whistler wave wiggler, the beam electrons are the source of the energy needed to produce electromagnetic radiation. The strength and the period of the wiggler field depend on the parameters of the magnetoplasma medium. This configuration has a higher tunability by controlling the plasma density, on top of the {gamma}-tunability of the conventional FELs. The theory of linear gain and electron trajectories was presented and four groups (I, II, III, and IV) of electron orbits were found in the presence of an axial guide magnetic field. Using perturbation analysis, it is found that these groups of orbits were stable except small regions of group I and IV orbits. The function {Phi} which determines the rate of change of axial velocity with beam energy was also derived. In the case in which {Phi}<0 represents a negative-mass regime in which the axial velocity accelerates as the electrons lose energy. Numerical solutions showed that by increasing the cyclotron frequency, the gain for group I and III orbits increased, while a gain decrement was obtained for group II and IV orbits.
Jafarinia, F.; Jafari, S. [Department of Physics, University of Guilan, Rasht 41335-1914 (Iran, Islamic Republic of); Mehdian, H. [Department of Physics and Institute for Plasma Research, Tarbiat Moallem University, Tehran 15614 (Iran, Islamic Republic of)
Beyond the Standard Model � Searches with a Free-Electron Laser
Much of the focus of Beyond the Standard Model physics searches is on the TeV scale, making use of hadron and lepton colliders. Additionally, however, there is the means to make these searches in different regions of parameter space using sub-electron volt photons from a Free Electron Laser, for example. We report on the experimental results of searches for opticalwavelength photons mixing with hypothetical hidden-sector paraphotons in the mass range between 10^-5 and 10^-2 electron volts for a mixing parameter greater than 10-7. We also report on the results of a sensitive search for scalar coupling of photons to light neutral bosons in the mass range of approximately 1.0 milli-electron volts and coupling strength greater than 10-6 GeV-1. These were generation-regeneration experiments using the �light shining through a wall� technique in which regenerated photons are searched for downstream of an optical barrier that separates it from an upstream generation region. The present results indicate no evidence for photon-paraphoton mixing or for scalar couplings of bosons to photons for the range of parameters investigated.
A. Afanasev, O.K. Baker, K.B. Beard, G. Biallas, J. Boyce, M. Minarni, R. Ramdon, Michelle D. Shinn, P. Slocumb
A New Gated X-Ray Detector for the Orion Laser Facility
Gated X-Ray Detectors (GXD) are considered the work-horse target diagnostic of the laser based inertial confinement fusion (ICF) program. Recently, Los Alamos National Laboratory (LANL) has constructed three new GXDs for the Orion laser facility at the Atomic Weapons Establishment (AWE) in the United Kingdom. What sets these three new instruments apart from the what has previously been constructed for the National Ignition Facility (NIF) at Lawrence Livermore National Laboratory (LLNL) is: improvements in detector head microwave transmission lines, solid state embedded hard drive and updated control software, and lighter air box design and other incremental mechanical improvements. In this paper we will present the latest GXD design enhancements and sample calibration data taken on the Trident laser facility at Los Alamos National Laboratory using the newly constructed instruments.
Clark, David D. [Los Alamos National Laboratory; Aragonez, Robert J. [Los Alamos National Laboratory; Archuleta, Thomas N. [Los Alamos National Laboratory; Fatherley, Valerie E. [Los Alamos National Laboratory; Hsu, Albert H. [Los Alamos National Laboratory; Jorgenson, H. J. [Los Alamos National Laboratory; Mares, Danielle [Los Alamos National Laboratory; Oertel, John A. [Los Alamos National Laboratory; Oades, Kevin [Atomic Weapons Establishment; Kemshall, Paul [Atomic Weapons Establishment; Thomas, Philip [Atomic Weapons Establishment; Young, Trevor [Atomic Weapons Establishment; Pederson, Neal [VI Control Systems
Effect of plasma density scale length on the properties of bremsstrahlung x-ray sources created by picosecond laser pulses
Results of an experimental study of multi-MeV bremsstrahlung x-ray sources created by picosecond laser pulses are presented. The x-ray source is created by focusing the short pulse in an expanding plasma obtained by heating a solid target with a time-delayed nanosecond laser beam. The high-energy part of the x-ray spectrum and emission lobe are inferred from photonuclear activation techniques. The x-ray dose is measured with silicon diodes. Two-dimensional images of the source are reconstructed from a penumbral imaging technique. These results indicate the creation of a relatively small source, below 200 {mu}m diameter, delivering doses up to 12 mrad in air at 1 m with x-ray temperature up to 2.8 MeV. The diagnostics used give access to a whole set of coherent experimental results on the x-ray source properties which are compared to extensive numerical simulations. X-ray intensity and temperature are found to increase with the size of the preplasma.
Courtois, C.; Compant La Fontaine, A.; Landoas, O.; Lidove, G.; Meot, V.; Morel, P.; Nuter, R.; Lefebvre, E. [CEA, DAM, DIF, F-91297 Arpajon (France); Boscheron, A.; Grenier, J. [CEA, DAM, CESTA, F-33114 Le Barp (France); Aleonard, M. M.; Gerbaux, M.; Gobet, F.; Hannachi, F.; Malka, G.; Scheurer, J. N.; Tarisien, M. [Universite de Bordeaux, Centre d'Etudes Nucleaires Bordeaux Gradignan, UMR 5797 CNRS/IN2P3, Gradignan F-33175 (France)
Proposed Laser-driven, Dielectric Microstructure Few-cm Long Undulator for Attosecond Coherent X-rays
This article presents the concept of an all-dielectric laser-driven undulator for the generation of coherent X-rays. The proposed laser-driven undulator is expected to produce internal deflection forces equivalent to a several-Tesla magnetic field acting on a speed-of-light particle. The key idea for this laser-driven undulator is its ability to provide phase synchronicity between the deflection force and the electron beam for a distance that is much greater than the laser wavelength. The potential advantage of this undulator is illustrated with a possible design example that assumes a small laser accelerator which delivers a 2 GeV, 1 pC, 1 kHz electron bunch train to a 10 cm long, 1/2 mm period laser-driven undulator. Such an undulator could produce coherent X-ray pulses with {approx}10{sup 9} photons of 64 keV energy. The numerical modeling for the expected X-ray pulse shape was performed with GENESIS, which predicts X-ray pulse durations in the few-attosecond range. Possible applications for nonlinear electromagnetic effects from these X-ray pulses are briefly discussed.
Plettner, T; Byer, R.L.; /Stanford U., Ginzton Lab.
Resonant Auger Decay of Molecules in Intense X-Ray Laser Fields: Light-Induced Strong Nonadiabatic Effects
The resonant Auger process is studied in intense x-ray laser fields. It is shown that the dressing of the initial and decaying states by the field leads to coupled complex potential surfaces which, even for diatomic molecules, possess intersections at which the nonadiabatic couplings are singular. HCl is studied as an explicit showcase example. The exact results differ qualitatively from those without rotations. A wealth of nonadiabatic phenomena is expected in decay processes in intense x-ray fields.
Cederbaum, Lorenz S.; Chiang, Ying-Chih; Demekhin, Philipp V. [Theoretische Chemie, Universitaet Heidelberg, Im Neuenheimer Feld 229, 69120 Heidelberg (Germany); Moiseyev, Nimrod [Schulich Faculty of Chemistry and Minerva Center, Technion--Israel Institute of Technology, Haifa 32000 (Israel)
Cluster beam targets for laser plasma extreme ultraviolet and soft x-ray sources
Method and apparatus for producing extreme ultraviolet (EUV) and soft x-ray radiation from an ultra-low debris plasma source are disclosed. Targets are produced by the free jet expansion of various gases through a temperature controlled nozzle to form molecular clusters. These target clusters are subsequently irradiated with commercially available lasers of moderate intensity (10{sup 11}--10{sup 12} watts/cm{sup 2}) to produce a plasma radiating in the region of 0.5 to 100 nanometers. By appropriate adjustment of the experimental conditions the laser focus can be moved 10--30 mm from the nozzle thereby eliminating debris produced by plasma erosion of the nozzle. 5 figs.
Kublak, G.D.; Richardson, M.C.
Method and apparatus for producing extreme ultra violet (EUV) and soft x-ray radiation from an ultra-low debris plasma source are disclosed. Targets are produced by the free jet expansion of various gases through a temperature controlled nozzle to form molecular clusters. These target clusters are subsequently irradiated with commercially available lasers of moderate intensity (10.sup.11 -10.sup.12 watts/cm.sup.2) to produce a plasma radiating in the region of 0.5 to 100 nanometers. By appropriate adjustment of the experimental conditions the laser focus can be moved 10-30 mm from the nozzle thereby eliminating debris produced by plasma erosion of the nozzle.
Kublak, Glenn D. (124 Turquoise Way, Livermore, Alameda County, CA 94550); Richardson, Martin C. (CREOL
SLAC National Accelerator Laboratory - Ultrafast Lasers at the...
Lasers at the Linac Coherent Light Source By Alan Fry, LCLS Laser Group July 5, 2011 The Linac Coherent Light Source at SLAC is the world's first hard X-ray free-electron laser, or...
High Flux Water Window X-rays Driven by Ultrashort 1.8mm Laser ...
About this Abstract. Meeting, Materials Science & Technology 2013. Symposium, Optical and X-ray Imaging Techniques for Material Characterization.
Enhanced inner-shell x-ray emission by femtosecond-laser irradiation of solid cone targets
The possibility of enhancing inner-shell x-ray emission, especially K{alpha} emission, by femtosecond-laser irradiation of solid cones instead of foils was investigated theoretically. In a model for hot electron (HE) transport and K{alpha} x-ray generation, K{alpha} emission from laser-irradiated solid cones and foils is investigated. As a complementarity to the model, the contributions from electric and magnetic fields generated by the HE current in solid cones and foils are discussed. The results indicate that the efficiency of HE energy conversion to K{alpha} photons is improved and the optimum HE temperature is increased.
Li Xiaoya; Zhu Wenjun; Ye Yan; Li Jun; Yu Yong [National Key Laboratory of Shock Wave and Detonation Physics, Mianyang, 621900 Sichuan (China); Wang Jiaxiang [State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200062 (China)
Observation of Laser Induced Magnetization Dynamics in Co/Pd Multilayers with Coherent X-ray Scattering
We report on time-resolved coherent x-ray scattering experiments of laser induced magnetization dynamics in Co/Pd multilayers with a high repetition rate optical pump x-ray probe setup. Starting from a multi-domain ground state, the magnetization is uniformly reduced after excitation by an intense 50 fs laser pulse. Using the normalized time correlation, we study the magnetization recovery on a picosecond timescale. The dynamic scattering intensity is separated into an elastic portion at length scales above 65 nm which retains memory of the initial domain magnetization, and a fluctuating portion at smaller length scales corresponding to domain boundary motion during recovery.
Wu, Benny
X-ray lasers and methods utilizing two component driving illumination provided by optical laser means of relatively low energy and small physical size
It is an object of this invention to provide an X-ray laser that is driven by an optical laser or lasers of relatively low energy and small physical size. Another object of this invention is to provide a method of driving an X-ray laser with an optical laser or lasers of relatively low energy and small physical size. Additional objects, advantages and novel features of the invention are set forth in part in the description included in this report. The objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims. 8 figs.
Rosen, M.D.; Matthews, D.L.
Spectral analysis of x-ray emission created by intense laser irradiation of copper materials
We have measured the x-ray emission, primarily from K{sub {alpha}},K{sub {beta}}, and He{sub {alpha}} lines, of elemental copper foil and 'foam' targets irradiated with a mid-10{sup 16} W/cm{sup 2} laser pulse. The copper foam at 0.1 times solid density is observed to produce 50% greater He{sub {alpha}} line emission than copper foil, and the measured signal is well-fit by a sum of three synthetic spectra generated by the atomic physics code FLYCHK. Additionally, spectra from both targets reveal characteristic inner shell K{sub {alpha}} transitions from hot electron interaction with the bulk copper. However, only the larger-volume foam target produced significant K{sub {beta}} radiation, confirming a lower bulk temperature in the higher volume sample.
Huntington, C. M.; Kuranz, C. C.; Drake, R. P. [Atmospheric, Oceanic, Space Science, University of Michigan, Ann Arbor, Michigan 48103 (United States); Malamud, G. [Atmospheric, Oceanic, Space Science, University of Michigan, Ann Arbor, Michigan 48103 (United States); Department of Physics, Nuclear Research Center - Negev, 84190 Beer-Sheva (Israel); Park, H.-S.; Maddox, B. R. [Lawrence Livermore National Laboratory, Livermore, California 94551 (United States)
X-ray backlight measurement of preformed plasma by kJ-class petawatt LFEX laser
Foot and pedestal pulses that precede the main pulse from a high-intensity laser greatly affect laser-plasma interactions. Especially in fast ignition schemes, preceding pulses generate a plasma prior to irradiation by the main pulse. This results in a too energetic and divergent electron beam being generated in the preformed plasma, which reduces the energy coupling efficiency from the heating laser to the dense fuel core. A preformed plasma with a density scale length of 40-60 {mu}m was observed by a time- and space-resolved x-ray backlight technique using the LFEX laser system at the Institute of Laser Engineering, Osaka University. Preceding pulses (i.e., the foot and pedestal) of the LFEX were characterized by comparing observations with calculations results obtained using a two-dimension (2D) radiation-hydrodynamic simulation code. In a separate experiment, the 2D code was benchmarked with the experimentally observed hydrodynamic behavior of a gold plasma produced by a nanosecond laser pulse that mimicked foot and pedestal pulses (intensity: 1 Multiplication-Sign 10{sup 11}-1 Multiplication-Sign 10{sup 12}W/cm{sup 2}). The preceding pulses were estimated to have an intensity of 1 Multiplication-Sign 10{sup 12}-10{sup 13}W/cm{sup 2}, a duration of 2.0 ns, and a spot diameter at the target of 200-600 {mu}m by comparing the measured hydrodynamics of the preformed plasma with that calculated by the 2D hydrodynamic simulation code.
Ohira, Shinji; Fujioka, Shinsuke; Nagatomo, Hideo; Matsuo, Satoshi; Morio, Noboru; Kawanaka, Jyunji; Nakata, Yoshiki; Miyanaga, Noriaki; Shiraga, Hiroyuki; Nishimura, Hiroaki; Azechi, Hiroshi [Institute of Laser Engineering, Osaka University, 2-6 Yamada-oka, Suita Osaka 565-0871 (Japan); Sunahara, Atsushi [Institute for Laser Technology, 2-6 Yamada-oka, Suita Osaka 565-0871 (Japan); Johzaki, Tomoyuki [Graduate School of Engineering, Hiroshima University, 1-4-1 Kagamiyama, Higashi Hiroshima 739-8527 (Japan)
Towards hard x-ray imaging at GHz frame rate
Gigahertz (GHz) imaging using hard x-rays ( Greater-Than-Or-Equivalent-To 10 keV) can be useful to high-temperature plasma experiments, as well as research and applications using coherent photons from synchrotron radiation and x-ray free electron lasers. GHz framing rate can be achieved by using multiple cameras through multiplexing. The advantages and trade-offs of single-photon detection mode, when no more than one x-ray photon is detected per pixel, are given. Two possible paths towards x-ray imaging at GHz frame rates using a single camera are: (a) avalanche photodiode arrays of high-Z materials and (b) microchannel plate photomultipliers in conjunction with materials with large indices of refraction.
Wang Zhehui; Morris, C. L.; Kapustinsky, J. S.; Kwiatkowski, K.; Luo, S.-N. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)
Towards hard X-ray imaging at GHz frame rate
Gigahertz (GHz) imaging using hard X-rays ({approx}> 10 keV) can be useful to high-temperature plasma experiments, as well as research using coherent photons from synchrotron radiation and X-ray free electron lasers. GHz framing rate can be achieved by using multiple cameras through multiplexing. The advantages and trade-offs of single-photon detection mode, when no more than one X-ray photon is detected per pixel, are given. Two possible paths towards X-ray imaging at GHz frame rates using a single camera are (a) Avalanche photodiode arrays of high-Z materials and (b) Microchannel plate photomultipliers in conjunction with materials with large indices of refraction.
Wang, Zhehui [Los Alamos National Laboratory; Morris, Christopher [Los Alamos National Laboratory; Luo, Shengnian [Los Alamos National Laboratory; Kwiatkowski, Kris K. [Los Alamos National Laboratory; Kapustinsky, Jon S. [Los Alamos National Laboratory
X-ray generator
Apparatus and method for producing coherent secondary x-rays that are controlled as to direction by illuminating a mixture of high z and low z gases with an intense burst of primary x-rays. The primary x-rays are produced with a laser activated plasma, and these x-rays strip off the electrons of the high z atoms in the lasing medium, while the low z atoms retain their electrons. The neutral atoms transfer electrons to highly excited states of the highly striped high z ions giving an inverted population which produces the desired coherent x-rays. In one embodiment, a laser, light beam provides a laser spark that produces the intense burst of coherent x-rays that illuminates the mixture of high z and low z gases, whereby the high z atoms are stripped while the low z ones are not, giving the desired mixture of highly ionized and neutral atoms. To this end, the laser spark is produced by injecting a laser light beam, or a plurality of beams, into a first gas in a cylindrical container having an adjacent second gas layer co-axial therewith, the laser producing a plasma and the intense primary x-rays in the first gas, and the second gas containing the high and low atomic number elements for receiving the primary x-rays, whereupon the secondary x-rays are produced therein by stripping desired ions in a neutral gas and transfer of electrons to highly excited states of the stripped ions from the unionized atoms. Means for magnetically confining and stabilizing the plasma are disclosed for controlling the direction of the x-rays.
Dawson, John M. (Los Angeles, CA)
Femtosecond Time-Delay X-ray Holography
Time-Delay X-ray Holography Time-Delay X-ray Holography X-ray free-electron lasers (XFELs) will produce photon pulses with a unique and desirable combination of properties. Their short X-ray wavelengths allow penetration into materials and the ability to probe structure at and below the nanometer scale. Their ultra-short duration gives information about this structure at the fundamental time-scales of atoms and molecules. The extreme intensity of the pulses will allow this information to be acquired in a single shot, so that these studies can be carried out on non-repeatable processes or on weakly-scattering objects that will be modified by the pulse. A fourth property of XFEL pulses is their high transverse coherence, which brings the promise of decades of innovation in visible optics to the X-ray regime, such as holography, interferometry, and laser-based imaging. Making an effective use of XFEL pulses, however, will benefit from innovations that are new to both X-ray science and coherent optics. One such innovation is the new method of time-delay X-ray holography [i], recently demonstrated at the FLASH FEL at DESY in Hamburg, to measure the evolution of objects irradiated by intense pulses.
An X-ray laser (10), and related methodology, are disclosed wherein an X-ray laser target (12) is illuminated with a first pulse of optical laser radiation (14) of relatively long duration having scarcely enough energy to produce a narrow and linear cool plasma of uniform composition (38). A second, relatively short pulse of optical laser radiation (18) is uniformly swept across the length, from end to end, of the plasma (38), at about the speed of light, to consecutively illuminate continuously succeeding portions of the plasma (38) with optical laser radiation having scarcely enough energy to heat, ionize, and invert them into the continuously succeeding portions of an X-ray gain medium. This inventive double pulse technique results in a saving of more than two orders of magnitude in driving optical laser energy, when compared to the conventional single pulse approach.
Rosen, Mordecai D. (Berkeley, CA); Matthews, Dennis L. (El Granada, CA)
LUX - A design study for a linac/laser-based ultrafast X-ray source
comparable to third generation light sources, to multipleexisting third generation light sources. The x-ray pulseof existing 3 rd generation light sources. The position of
Electron spectra of xenon clusters irradiated with a laser-driven plasma soft-x-ray laser pulse
Xenon clusters were irradiated with plasma soft-x-ray laser pulses (having a wavelength of 13.9 nm, time duration of 7 ps, and intensities of up to 10 GW/cm{sup 2}). The laser photon energy was high enough to photoionize 4d core electrons. The cross section is large due to a giant resonance. The interaction was investigated by measuring the electron energy spectra. The photoelectron spectra for small clusters indicate that the spectral width due to the 4d hole significantly broadens with increasing cluster size. For larger clusters, the electron energy spectra evolve into a Maxwell-Boltzmann distribution, as a strongly coupled cluster nanoplasma is generated.
Namba, S.; Takiyama, K. [Graduate School of Engineering, Hiroshima University, 1-4-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8527 (Japan); Hasegawa, N.; Kishimoto, M.; Nishikino, M.; Kawachi, T. [Quantum Beam Science Directorate, Japan Atomic Energy Agency, 8-1-7 Umemidai, Kizugawa, Kyoto 619-0215 (Japan)
rf modulator design and phase amplitude control for a high-power free-electron-laser linac
The continued interest for building tunable lasers using an electron accelerator as the source of primary energy has resulted in the design of a new accelerator. Earlier work by other members of the Los Alamos team has demonstrated that this design does work in an amplifier mode. The accelerator is to be upgraded for use in an oscillator experiment and the new rf power amplifier system must meet some of the very stringent demands for power and stability placed on the electron beam for the free-electron laser (FEL) interaction to be observed. These demands are particularly stringent because the electron beam energy ultimately will be circulated back through the accelerator so that the electron beam energy not used in the FEL interaction is not wasted. These considerations have to some measure been incorporated into the design of the second FEL system at Los Alamos and are discussed.
Hoeberling, R.F.; Tallerico, P.J.
from the start as a user facility for femtosecond x-rayusers simultaneously, while the whole spectrum of already-available x-ray determinations, long a staple at existing synchrotron facilities,
X-ray beamsplitter
An x-ray beamsplitter which splits an x-ray beam into two coherent parts by reflecting and transmitting some fraction of an incident beam has applications for x-ray interferometry, x-ray holography, x-ray beam manipulation, and x-ray laser cavity output couplers. The beamsplitter is formed of a wavelength selective multilayer thin film supported by a very thin x-ray transparent membrane. The beamsplitter resonantly transmits and reflects x-rays through thin film interference effects. A thin film is formed of 5-50 pairs of alternate Mo/Si layers with a period of 20-250 A. The support membrane is 10-200 nm of silicon nitride or boron nitride. The multilayer/support membrane structure is formed across a window in a substrate by first forming the structure on a solid substrate and then forming a window in the substrate to leave a free-standing structure over the window.
Ceglio, Natale M. (Livermore, CA); Stearns, Daniel S. (Mountain View, CA); Hawryluk, Andrew M. (Modesto, CA); Barbee, Jr., Troy W. (Palo Alto, CA)
Free-electron lasers for strategic defense: the benefits of scientific open scientific exchange
A dominant theme of the Fifth International Seminar on Nuclear War, held at Erice, Sicily, (August 19-24, 1985), was the appeal for openness in science and in technological research. In his address to the seminar, Italian Foreign Minister Giulio Andreotti cited the remarkable achievements at the European Center for Nuclear Research (CERN), as an inspiring example of the benefits of scientific collaboration across national borders - science without frontiers. Dr. Edward Teller eloquently argued that, ''thanks to a nearly complete lack of official secrecy, computer technology has fluorished in the free societies of the United States, Japan, and Western Europe.'' The superiority of this technology, vis-a-vis its status in the Soviet bloc, has enhanced both the national security and the economic vitality of the United States and its allies. A further example of the success of science without secrecy can be found in another technology of major importance to the goals of America's Strategic Defense Initiative (SDI). The technology of note is the free electron-l'Ser (FEL).
Barletta, W.A.
A dual-channel, curved-crystal spectrograph for petawatt laser, x-ray backlighter source studies
A dual-channel, curved-crystal spectrograph was designed to measure time-integrated x-ray spectra in the {approx}1.5 to 2 keV range (6.2-8.2 A wavelength) from small-mass, thin-foil targets irradiated by the VULCAN petawatt laser focused up to 4x10{sup 20} W/cm{sup 2}. The spectrograph consists of two cylindrically curved potassium-acid-phthalate crystals bent in the meridional plane to increase the spectral range by a factor of {approx}10 compared to a flat crystal. The device acquires single-shot x-ray spectra with good signal-to-background ratios in the hard x-ray background environment of petawatt laser-plasma interactions. The peak spectral energies of the aluminum He{sub {alpha}} and Ly{sub {alpha}} resonance lines were {approx}1.8 and {approx}1.0 mJ/eV sr ({approx}0.4 and 0.25 J/A sr), respectively, for 220 J, 10 ps laser irradiation.
Theobald, W.; Stoeckl, C.; Jaanimagi, P. A.; Nilson, P. M.; Storm, M.; Meyerhofer, D. D.; Sangster, T. C. [Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623-1299 (United States); Hey, D.; MacKinnon, A. J.; Park, H.-S.; Patel, P. K.; Shepherd, R.; Snavely, R. A.; Key, M. H. [Lawrence Livermore National Laboratory, 7000 East Ave., Livermore, California 94550-9234 (United States); King, J. A.; Zhang, B. [Department of Applied Sciences, University of California, Davis, Davis, California 95616 (United States); Stephens, R. B.; Akli, K. U. [General Atomics, San Diego, California 92186 (United States); Highbarger, K.; Daskalova, R. L. [College of Mathematical and Physical Sciences, Ohio State University, Columbus, Ohio 43210 (United States); and others
The analysis of single-electron orbits in a free electron laser based upon a rectangular hybrid wiggler
A three-dimensional analysis of a novel free-electron laser (FEL) based upon a rectangular hybrid wiggler (RHW) is presented. This RHW is designed in a configuration composed of rectangular rings with alternating ferrite and dielectric spacers immersed in a solenoidal magnetic field. An analytic model of RHW is introduced by solution of Laplace's equation for the magnetostatic fields under the appropriate boundary conditions. The single-electron orbits in combined RHW and axial guide magnetic fields are studied when only the first and the third spatial harmonic components of the RHW field are taken into account and the higher order terms are ignored. The results indicate that the third spatial harmonic leads to group III orbits with a strong negative mass regime particularly in large solenoidal magnetic fields. RHW is found to be a promising candidate with favorable characteristics to be used in microwave FEL.
Kordbacheh, A.; Ghahremaninezhad, Roghayeh [Department of Physics, Iran University of Science and Technology, 1684613114 Tehran (Iran, Islamic Republic of); Maraghechi, B. [Department of Physics, Amirkabir University of Technology, 159163411 Tehran (Iran, Islamic Republic of)
Subpicosecond 41.8-nm X-ray laser in the plasma produced by femtosecond laser irradiation of a xenon cluster jet
Model calculations are performed of the radiation gain for the 4d5d (J = 0) - 4d5p (J = 1) transition with a wavelength of 41.8 nm in Pd-like xenon ions in the plasma produced by femtosecond laser irradiation of a xenon cluster jet. Conditions for the excitation of an ultrashort-pulse ({approx}1 ps) X-ray laser are discussed. (lasers)
Ivanova, E P [Institute of Spectroscopy, Russian Academy of Sciences, Troitsk, Moscow region (Russian Federation)
Novel x-ray imaging methods at the Nova Laser Facility
We are pursuing several novel x-ray imaging schemes to measure plasma parameters in inertial-confinement fusion experiments. This paper will review two quite successful approaches, the soft x-ray moire deflectometer, and the annular (ring) coded-aperture microscope. The deflectometer is the newer diagnostic, and this paper will concentrate on this topic. We will describe the operating principles of moire deflectometry, give the motivations for soft x-ray probing, describe the physical apparatus in detail, and present some sample images and results. The ring coded-aperture microscope has been described previously, so here we will only briefly review the principle of the instrument. We will concentrate on the signal-to-noise ratio calculations that motivate the use of annular coded apertures, and describe recent work to predict and measure the resolution of the instrument.
Ress, D.; DaSilva, L.B.; London, R.A.; Trebes, J.E.; Lerche, R.A. [Lawrence Livermore National Lab., CA (United States); Bradley, D.K. [Rochester Univ., NY (United States). Lab. for Laser Energetics
Soft x-ray scattering using FEL radiation for probing near-solid density plasmas at few electronvolt temperatures
We report on soft x-ray scattering experiments on cryogenic hydrogen and simple metal targets. As a source of intense and ultrashort soft x-ray pulses we have used free-electron laser radiation at 92 eV photon energy from FLASH at DESY, Hamburg. X-ray pulses with energies up to 100 {micro}J and durations below 50 fs provide interaction with the target leading simultaneously to plasma formation and scattering. Experiments exploiting both of these interactions have been carried out, using the same experimental setup. Firstly, recording of soft x-ray inelastic scattering from near-solid density hydrogen plasmas at few electronvolt temperatures confirms the feasibility of this diagnostics technique. Secondly, the soft x-ray excitation of few electronvolt solid-density plasmas in simple metals could be studied by recording soft x-ray line and continuum emission integrated over emission times from fs to ns.
Toleikis, S; Faustlin, R R; Cao, L; Doppner, T; Dusterer, S; Forster, E; Fortmann, C; Glenzer, S H; Gode, S; Gregori, G; Irsig, R; Laarmann, T; Lee, H J; Li, B; Meiwes-Broer, K; Przystawik, A; Radcliffe, P; Redmer, R; Tavella, F; Thiele, R; Tiggesbaumker, J; Truong, N X; Uschmann, I; Zastrau, U; Tschentscher, T
Scaling of Pressure with Intensity in Laser-Driven Shocks and Effects of Hot X-ray Preheat
To drive shocks into solids with a laser we either illuminate the material directly, or to get higher pressures, illuminate a plastic ablator that overlays the material of interest. In both cases the illumination intensity is low, <<10{sup 13} W/cm{sup 2}, compared to that for traditional laser fusion targets. In this regime, the laser beam creates and interacts with a collisional, rather than a collisionless, plasma. We present scaling relationships for shock pressure with intensity derived from simulations for this low-intensity collisional plasma regime. In addition, sometimes the plastic-ablator targets have a thin flashcoating of Al on the plastic surface as a shine-through barrier; this Al layer can be a source of hot x-ray preheat. We discuss how the preheat affects the shock pressure, with application to simulating VISAR measurements from experiments conducted on various lasers on shock compression of Fe.
Colvin, J D; Kalantar, D H
Electron beam magnetic switch for a plurality of free electron lasers
Apparatus for forming and utilizing a sequence of electron beam segments, each of the same temporal length (substantially 15 nsec), with consecutive beams being separated by a constant time interval of the order of 3 nsec. The beam sequence is used for simultaneous inputs to a plurality of wiggler magnet systems that also accept the laser beams to be amplified by interaction with the co-propagating electron beams. The electron beams are arranged substantially in a circle to allow proper distribution of and simultaneous switching out of the beam segments to their respective wiggler magnets.
Schlitt, Leland G. (Livermore, CA)
Electron-beam magnetic switch for a plurality of free-electron lasers
Apparatus for forming and utilizing a sequence of electron beam segments, each of the same temporal length (substantially 15 nsec), with consecutive beams being separated by a constant time interval of the order of 3 nsec is described. The beam sequence is used for simultaneous inputs to a plurality of wiggler magnet systems that also accept the laser beams to be amplified by interaction with the co-propagating electron beams. The electron beams are arranged substantially in a circle to allow proper distribution of and simultaneous switching out of the beam segments to their respective wiggler magnets.
Schlitt, L.G.
CRC handbook of laser science and technology. Volume 1. Lasers and masers
This book describes various types of lasers and masers. The following topics are discussed in detail: types and comparisons of laser sources, crystal and glass lasers, semiconductor lasers, organic dye and other liquid lasers, free-electron and x-ray lasers, masers and laser safety.
Weber, M.J.
Comment on ''Chaotic electron trajectories in an electromagnetic wiggler free-electron laser with ion-channel guiding'' [Phys. Plasmas 17, 093103 (2010)
The chaotic electron dynamics in a free-electron laser with electromagnetic-wave wiggler and ion-channel has been recently reported by A. Taghavi et al.[Phys. Plasmas 17, 093103 (2010)]. We comment on the authors use of a set of initial condition that is not correct based on the dispersion relation and steady-state orbits.
Nasr, N.; Hasanbeigi, A. [Department of Physics and Institute for Plasma Research, Tarbiat Moallem University, 49 Dr Mofatteh Avenue, Tehran 15614 (Iran, Islamic Republic of)
Proton- and x-ray beams generated by ultra-fast CO(2) lasers for medical applications
Recent progress in using picosecond CO{sub 2} lasers for Thomson scattering and ion-acceleration experiments underlines their potentials for enabling secondary radiation- and particle-sources. These experiments capitalize on certain advantages of long-wavelength CO{sub 2} lasers, such as higher number of photons per energy unit, and favorable scaling of the electrons ponderomotive energy and critical plasma density. The high-flux x-ray bursts produced by Thomson scattering of the CO{sub 2} laser off a counter-propagating electron beam enabled high-contrast, time-resolved imaging of biological objects in the picosecond time frame. In different experiments, the laser, focused on a hydrogen jet, generated monoenergetic proton beams via the radiation-pressure mechanism. The strong power-scaling of this regime promises realization of proton beams suitable for laser-driven proton cancer therapy after upgrading the CO{sub 2} laser to sub-PW peak power. This planned improvement includes optimizing the 10-{mu}m ultra-short pulse generation, assuring higher amplification in the CO{sub 2} gas under combined isotopic- and power-broadening effects, and shortening the postamplification pulse to a few laser cycles (150-200 fs) via chirping and compression. These developments will move us closer to practical applications of ultra-fast CO{sub 2} lasers in medicine and other areas.
Pogorelsky, I.; Polyanskiy, M.; Yakimenko, V.; Ben-Zvi, I.; Shkolnikov, P. Najmudin, Z.; Palmer, C.A.J.; Dover, N.P.; Oliva, P; Carpinelli, M.
Computational Simulations of High Intensity X-Ray Matter Interaction
Free electron lasers have the promise of producing extremely high-intensity short pulses of coherent, monochromatic radiation in the 1-10 keV energy range. For example, the Linac Coherent Light Source at Stanford is being designed to produce an output intensity of 2 x 10{sup 14} W/cm{sup 2} in a 230 fs pulse. These sources will open the door to many novel research studies. However, the intense x-ray pulses may damage the optical components necessary for studying and controlling the output. At the full output intensity, the dose to optical components at normal incidence ranges from 1-10 eV/atom for low-Z materials (Z < 14) at photon energies of 1 keV. It is important to have an understanding of the effects of such high doses in order to specify the composition, placement, and orientation of optical components, such as mirrors and monochromators. Doses of 10 eV/atom are certainly unacceptable since they will lead to ablation of the surface of the optical components. However, it is not precisely known what the damage thresholds are for the materials being considered for optical components for x-ray free electron lasers. In this paper, we present analytic estimates and computational simulations of the effects of high-intensity x-ray pulses on materials. We outline guidelines for the maximum dose to various materials and discuss implications for the design of optical components.
London, R A; Rionta, R; Tatchyn, R; Roessler, S
Lasers without Mirrors, Designed by Supercomputer - NERSC SCience...
it takes a big machine to understand the tiniest details. That's the case with free electron lasers (FELs). The powerful X-rays they generate can probe matter directly at...
A high-repetition rate scheme for synchrotron-based picosecond laser pump/x-ray probe experiments on chemical and biological systems in solution
We present the extension of time-resolved optical pump/x-ray absorption spectroscopy (XAS) probe experiments towards data collection at MHz repetition rates. The use of a high-power picosecond laser operating at an integer fraction of the repetition rate of the storage ring allows exploitation of up to two orders of magnitude more x-ray photons than in previous schemes based on the use of kHz lasers. Consequently, we demonstrate an order of magnitude increase in the signal-to-noise of time-resolved XAS of molecular systems in solution. This makes it possible to investigate highly dilute samples at concentrations approaching physiological conditions for biological systems. The simplicity and compactness of the scheme allows for straightforward implementation at any synchrotron beamline and for a wide range of x-ray probe techniques, such as time-resolved diffraction or x-ray emission studies.
Lima, Frederico A.; Milne, Christopher J.; Amarasinghe, Dimali C. V.; Rittmann-Frank, Mercedes Hannelore; Veen, Renske M. van der; Reinhard, Marco; Pham, Van-Thai; Karlsson, Susanne; Mourik, Frank van; Chergui, Majed [Laboratoire de Spectroscopie Ultrarapide, Ecole Polytechnique Federale de Lausanne, ISIC, FSB, 1015 Lausanne (Switzerland); Johnson, Steven L.; Grolimund, Daniel; Borca, Camelia; Huthwelker, Thomas; Janousch, Markus [Swiss Light Source, Paul Scherrer Institut, 5232 Villigen (Switzerland); Abela, Rafael [SwissFEL, Paul Scherrer Institut, 5232 Villigen (Switzerland)
A multi-crystal wavelength dispersive x-ray spectrometer
A multi-crystal wavelength dispersive hard x-ray spectrometer with high-energy resolution and large solid angle collection is described. The instrument is specifically designed for time-resolved applications of x-ray emission spectroscopy (XES) and x-ray Raman scattering (XRS) at X-ray Free Electron Lasers (XFEL) and synchrotron radiation facilities. It also simplifies resonant inelastic x-ray scattering (RIXS) studies of the whole 2d RIXS plane. The spectrometer is based on the Von Hamos geometry. This dispersive setup enables an XES or XRS spectrum to be measured in a single-shot mode, overcoming the scanning needs of the Rowland circle spectrometers. In conjunction with the XFEL temporal profile and high-flux, it is a powerful tool for studying the dynamics of time-dependent systems. Photo-induced processes and fast catalytic reaction kinetics, ranging from femtoseconds to milliseconds, will be resolvable in a wide array of systems circumventing radiation damage.
Alonso-Mori, Roberto; Montanez, Paul; Delor, James; Bergmann, Uwe [LCLS, SLAC National Accelerator Laboratory, Menlo Park, California 94025 (United States); Kern, Jan [LCLS, SLAC National Accelerator Laboratory, Menlo Park, California 94025 (United States); Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720-8099 (United States); Sokaras, Dimosthenis; Weng, Tsu-Chien; Nordlund, Dennis [SSRL, SLAC National Accelerator Laboratory, Menlo Park, California 94025 (United States); Tran, Rosalie; Yachandra, Vittal K.; Yano, Junko [Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720-8099 (United States)
Soft X-Ray Thomson Scattering in Warm Dense Hydrogen at FLASH
We present collective Thomson scattering with soft x-ray free electron laser radiation as a method to track the evolution of warm dense matter plasmas with {approx}200 fs time resolution. In a pump-probe scheme an 800 nm laser heats a 20 {micro}m hydrogen droplet to the plasma state. After a variable time delay in the order of ps the plasma is probed by an x-ray ultra violet (XUV) pulse which scatters from the target and is recorded spectrally. Alternatively, in a self-Thomson scattering experiment, a single XUV pulse heats the target while a portion of its photons are being scattered probing the target. From such inelastic x-ray scattering spectra free electron temperature and density can be inferred giving insight on relaxation time scales in plasmas as well as the equation of state. We prove the feasibility of this method in the XUV range utilizing the free electron laser facility in Hamburg, FLASH. We recorded Thomson scattering spectra for hydrogen plasma, both in the self-scattering and in the pump-probe mode using optical laser heating.
Faustlin, R R; Toleikis, S; Bornath, T; Doppner, T; Dusterer, S; Forster, E; Fortmann, C; Glenzer, S H; Gode, S; Gregori, G; Irsig, R; Laarmann, T; Lee, H J; Li, B; Meiwes-Broer, K; Mithen, J; Przystawik, A; Redlin, H; Redmer, R; Reinholz, H; Ropke, G; Tavella, F; Thiele, R; Tiggesbaumker, J; Uschmann, I; Zastrau, U; Tschentscher, T
Resonant Auger decay of the core-excited C{sup *}O molecule in intense x-ray laser fields
The dynamics of the resonant Auger (RA) process of the core-excited C*O(1s{sup -1}{pi}*,v{sub r}=0) molecule in an intense x-ray laser field is studied theoretically. The theoretical approach includes the analog of the conical intersections of the complex potential energy surfaces of the ground and 'dressed' resonant states due to intense x-ray pulses, taking into account the decay of the resonance and the direct photoionization of the ground state, both populating the same final ionic states coherently, as well as the direct photoionization of the resonance state itself. The light-induced nonadiabatic effect of the analog of the conical intersections of the resulting complex potential energy surfaces gives rise to strong coupling between the electronic, vibrational, and rotational degrees of freedom of the diatomic CO molecule. The interplay of the direct photoionization of the ground state and of the decay of the resonance increases dramatically with the field intensity. The coherent population of a final ionic state via both the direct photoionization and the resonant Auger decay channels induces strong interference effects with distinct patterns in the RA electron spectra. The individual impact of these physical processes on the total electron yield and on the CO{sup +}(A {sup 2}{Pi}) electron spectrum are demonstrated.
Demekhin, Philipp V.; Chiang, Ying-Chih; Cederbaum, Lorenz S. [Theoretische Chemie, Physikalisch-Chemisches Institut, Universitaet Heidelberg, Im Neuenheimer Feld 229, D-69120 Heidelberg (Germany)
of coherent transition radiation generated at a plasma-and G. Fubiani, �Terahertz radiation from laser acceleratedW. P. Leemans, �Synchrotron radiation from electron beams in
Sub-Picosecond X-Ray Pulses Workshop
International Workshop on the Interactions of Intense Sub-Picosecond X-Ray International Workshop on the Interactions of Intense Sub-Picosecond X-Ray Pulses with Matter (SLAC, January 23-24, 1997) During the last five years studies have been conducted at the Stanford Linear Accelerator Center (SLAC) and the Deutsches Elektronen-Synchrotron (DESY) in Hamburg concerning the feasibility of driving an Angstrom-wavelength Free-Electron Laser (FEL) with a high energy rf linac. Recent promising advances in linac, rf gun, and insertion device technologies make it seem likely that such a device can be constructed. The output radiation predicted for this type of source will be characterized by full transverse coherence, extreme pulse brevity (~50-100 fs), high peak power (10-100 GW), and very high unfocused peak power density (0.4-4.1013
Theme Article - Time-Resolved X-Ray Scattering from Coherent Excitations in Solids
Recent advances in pulsed x-ray sources have opened up new opportunities to study the dynamics of matter directly in the time domain with picosecond to femtosecond resolution. In this article, we present recent results from a variety of ultrafast sources on time-resolved x-ray scattering from elementary excitations in periodic solids. A few representative examples are given on folded acoustic phonons, coherent optical phonons, squeezed phonons, and polaritons excited by femtosecond lasers. Next-generation light sources, such as the x-ray-free electron laser, will lead to improvements in coherence, flux, and pulse duration. These experiments demonstrate potential opportunities for studying matter far from equilibrium on the fastest time scales and shortest distances that will be available in the coming years.
Trigo, Mariano; Reis, David (SLAC)
The Next Challenge in X-Ray Science: Control of Resonant Electronic
The Next Challenge in X-Ray Science: Control of Resonant Electronic The Next Challenge in X-Ray Science: Control of Resonant Electronic Processes Wednesday, September 11, 2013 - 3:00pm SLAC, Redtail Hawk Conference Room 108A Joachim Stöhr, LCLS My talk will give a historic perspective of the revolutionary science that was enabled by the advent of high power sources of coherent electromagnetic radiation and the implications for future scientific opportunities with x-ray free electron lasers (X-FELs). The historical journey starts with the development of radar microwave sources in the 1940s that fueled the development of nuclear magnetic resonance (NMR) techniques which by now have led to 6 Nobel Prizes. The theoretical description of NMR as coherent processes between nuclear states by Rabi and Bloch also provided the theoretical basis for the optical laser and its applications. Over the last
The FERMI@Elettra free-electron-laser source for coherent X-ray physics: photon properties, beam transport system, and applications
49625-Rev. 1 (also SLAC Rpt. LCLS-TN-04-3) Fawley W M 2006wavelength FELs (e.g. , FLASH, LCLS, SCSS, XFEL, SPARX) have
Allaria, Enrico
Demonstration of an 8.85 nm Gain-Saturated Table-Top Soft X-Ray Laser and Lasing down to 7.4 nm
We report the efficient generation of a gain-saturated 8.85 nm wavelength table-top soft x-ray laser operating at 1 Hz repetition rate and the observation of lasing at wavelengths as short as 7.36 nm in lanthanide ions.
Wang, Yong [Colorado State University, Fort Collins; Alessi, David [Colorado State University, Fort Collins; Luther, Brad [Colorado State University, Fort Collins; Yin, Liang [Colorado State University, Fort Collins; Martz, Dale [Colorado State University, Fort Collins; Berrill, Mark A [ORNL; Jorge, Rocca [Colorado State University, Fort Collins
Soft X-ray laser using pumping of 3P and 4P levels of He-like and H-like ions
X-ray laser method and apparatus for producing coherent radiation at, for example, energies of at least 40 eV, using Be-like Cr, N-like Ni, He-like Na, B-like Cr, Be-like Mn or similar multiply ionized species to pump appropriate high energy transitions in He-like or H-like N, O, F, C or rare gases, with associated laser transition gains of 4-50 cm.sup.-1.
Hagelstein, Peter L. (Livermore, CA)
Soft x-ray laser using pumping of 3p and 4p levels of He-like and H-like ions
X-ray laser method and apparatus for producing coherent radiation at, for example, energies of at least 40 eV, using Be-like Cr, N-like Ni, He-like Na, B-like Cr, Be-like Mn or similar multiply ionized species to pump appropriate high energy transitions in He-like or H-like N, O, F, C or rare gases, with associated laser transition gains of 4 to 50 cm/sup -1/.
Hagelstein, P.L.
relevant to atomic and molecular phenomena) with the advantages of visible-light lasers (highly coherent beams). All of these characteristics are important for coherent x-ray...
Generation of iodine L-shell X-rays under excitation of large CF{sub 3}I clusters by femtosecond laser radiation
The use of clusters of polyatomic molecules with a relatively low ionisation energy ({approx}10 eV) is proposed for the efficient production of X-ray radiation. We have observed for the first time the generation of characteristic X-ray radiation due to L transitions in iodine atoms under the high-intensity femtosecond laser irradiation of molecular CF{sub 3}I clusters, which were a small admixture to Ar carrier gas. The X-ray conversion efficiency amounts to {approx}10{sup -6} (for a yield of {approx}10{sup 7} photons per pulse), which is an order of magnitude higher than the efficiency we obtained in the case of argon clusters under comparable conditions. (letters)
Gordienko, Vyacheslav M; Dzhidzhoev, M S; Zhvaniya, I A; Pribytkov, Andrei V; Trubnikov, Dmitrii N; Fedorov, D O
Ultra hard x rays from krypton clusters heated by intense laser fields R. C. Issac,a)
with gas-phase targets, x-ray sources derived from solid tar- gets have superior x-ray yields in the hard x. Hulin, P. Mono, J. Abdallah, Jr., A. Y. Faenov, I. Y. Skobelev, A. I. Magunov, and T. A. Pikuz, JETP
Strathclyde, University of
Efficient Excitation of Gain-Saturated Sub-9-nm-Wavelength Tabletop Soft-X-Ray Lasers and Lasing Down to 7.36 nm
We have demonstrated the efficient generation of sub-9-nm-wavelength picosecond laser pulses of microjoule energy at 1-Hz repetition rate with a tabletop laser. Gain-saturated lasing was obtained at =8.85 nm in nickel-like lanthanum ions excited by collisional electron-impact excitation in a precreated plasma column heated by a picosecond optical laser pulse of 4-J energy. Furthermore, isoelectronic scaling along the lanthanide series resulted in lasing at wavelengths as short as =7.36 nm. Simulations show that the collisionally broadened atomic transitions in these dense plasmas can support the amplification of subpicosecond soft-x-ray laser pulses.
Alessi, David [Colorado State University, Fort Collins; Wang, Yong [Colorado State University, Fort Collins; Luther, Brad [Colorado State University, Fort Collins; Yin, Liang [Colorado State University, Fort Collins; Martz, Dale [Colorado State University, Fort Collins; Woolston, Mark [Colorado State University, Fort Collins; Liu, Yanwei [University of California, Berkeley & LBNL; Berrill, Mark A [ORNL; Jorge, Rocca [Colorado State University, Fort Collins
X-ray pulse preserving single-shot optical cross-correlation method for improved experimental temporal resolution
We measured the relative arrival time between an optical pulse and a soft x-ray pulse from a free-electron laser. This femtosecond cross-correlation measurement was achieved by observing the change in optical reflectivity induced through the absorption of a fraction of the x-ray pulse. The main x-ray pulse energy remained available for an independent pump-probe experiment where the sample may be opaque to soft x-rays. The method was employed to correct the two-pulse delay data from a canonical pump-probe experiment and demonstrate 130 {+-} 20 fs (FWHM) temporal resolution. We further analyze possible timing jitter sources and point to future improvements.
Beye, M. [SIMES, SLAC National Accelerator Laboratory, Menlo Park, California 94025 (United States); Helmholtz-Zentrum Berlin fuer Materialien und Energie GmbH, 12489 Berlin (Germany); Krupin, O. [LCLS, SLAC National Accelerator Laboratory, Menlo Park, California 94025 (United States); European XFEL GmbH, 22607 Hamburg (Germany); Hays, G.; Jong, S. de; Lee, S.; Coffee, R.; Holmes, M. R.; Fry, A. R.; White, W. E.; Bostedt, C.; Schlotter, W. F. [LCLS, SLAC National Accelerator Laboratory, Menlo Park, California 94025 (United States); Reid, A. H. [SIMES, SLAC National Accelerator Laboratory, Menlo Park, California 94025 (United States); Radboud University Nijmegen, Institute for Molecules and Materials, 6525 AJ Nijmegen (Netherlands); Rupp, D. [Technische Universitaet Berlin, 10623 Berlin (Germany); LCLS, SLAC National Accelerator Laboratory, Menlo Park, California 94025 (United States); Lee, W.-S.; Scherz, A. O. [SIMES, SLAC National Accelerator Laboratory, Menlo Park, California 94025 (United States); Chuang, Y.-D. [Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Cryan, J. P.; Glownia, J. M. [PULSE, SLAC National Accelerator Laboratory, Menlo Park, California 94025 (United States); LCLS, SLAC National Accelerator Laboratory, Menlo Park, California 94025 (United States); Foehlisch, A. [Helmholtz-Zentrum Berlin fuer Materialien und Energie GmbH, 12489 Berlin (Germany); Durr, H. A. [SIMES, SLAC National Accelerator Laboratory, Menlo Park, California 94025 (United States); PULSE, SLAC National Accelerator Laboratory, Menlo Park, California 94025 (United States)
Hard x-ray monochromator with milli-electron volt bandwidth for high-resolution diffraction studies of diamond crystals
We report on design and performance of a high-resolution x-ray monochromator with a spectral bandwidth of {Delta}E{sub X}{approx_equal} 1.5 meV, which operates at x-ray energies in the vicinity of the backscattering (Bragg) energy E{sub H} = 13.903 keV of the (008) reflection in diamond. The monochromator is utilized for high-energy-resolution diffraction characterization of diamond crystals as elements of advanced x-ray crystal optics for synchrotrons and x-ray free-electron lasers. The monochromator and the related controls are made portable such that they can be installed and operated at any appropriate synchrotron beamline equipped with a pre-monochromator.
Stoupin, Stanislav; Shvyd'ko, Yuri; Shu Deming; Khachatryan, Ruben; Xiao, Xianghui; DeCarlo, Francesco; Goetze, Kurt; Roberts, Timothy; Roehrig, Christian; Deriy, Alexey [Advanced Photon Source, Argonne National Laboratory, Illinois 60439 (United States)
Hard x-ray monochromator with milli-electron volt bandwidth for high-resolution diffraction studies of diamond crystals.
We report on design and performance of a high-resolution x-ray monochromator with a spectral bandwidth of {Delta}E{sub x} {approx_equal} 1.5 meV, which operates at x-ray energies in the vicinity of the backscattering (Bragg) energy E{sub H} = 13.903 keV of the (008) reflection in diamond. The monochromator is utilized for high-energy-resolution diffraction characterization of diamond crystals as elements of advanced x-ray crystal optics for synchrotrons and x-ray free-electron lasers. The monochromator and the related controls are made portable such that they can be installed and operated at any appropriate synchrotron beamline equipped with a pre-monochromator.
Stoupin, S.; Shvydko, Y.; Shu, D.; Khachatryan, R.; Xiao, X. (X-Ray Science Division)
X-ray polarization spectroscopy to study anisotropic velocity distribution of hot electrons produced by an ultra-high-intensity laser
The anisotropy of the hot-electron velocity distribution in ultra-high-intensity laser produced plasma was studied with x-ray polarization spectroscopy using multilayer planar targets including x-ray emission tracer in the middle layer. This measurement serves as a diagnostic for hot-electron transport from the laser-plasma interaction region to the overdense region where drastic changes in the isotropy of the electron velocity distribution are observed. These polarization degrees are consistent with analysis of a three-dimensional polarization spectroscopy model coupled with particle-in-cell simulations. Electron velocity distribution in the underdense region is affected by the electric field of the laser and that in the overdense region becomes wider with increase in the tracer depth. A full-angular spread in the overdense region of 22.4 deg.{sub -2.4}{sup +5.4} was obtained from the measured polarization degree.
Inubushi, Y. [Institute of Laser Engineering, Osaka University, Suita, Osaka (Japan); Graduate School of Engineering, Osaka University, Suita, Osaka (Japan); Okano, Y.; Nishimura, H.; Cai, H.; Nagatomo, H.; Kai, T.; Fujioka, S.; Nakamura, T.; Johzaki, T.; Mima, K. [Institute of Laser Engineering, Osaka University, Suita, Osaka (Japan); Kawamura, T. [Tokyo Institute of Technology, Yokohama, Kanagawa (Japan); Batani, D.; Morace, A.; Redaelli, R. [Dipartmento di Fisica 'G. Occhialini', University of Milano-Bicocca, Milan (Italy); Fourment, C.; Santos, J. J.; Malka, G. [CELIA, Universite de Bordeaux/CNRS/CEA, Talence (France); Boscheron, A.; Bonville, O.; Grenier, J. [CEA/CESTA, Le Barp (France)
Efficient laser-induced 6-8 keV x-ray production from iron oxide aerogel and foil-lined cavity targets
The performance of new iron-based laser-driven x-ray sources has been tested at the OMEGA laser facility for production of x rays in the 6.5-8.5 keV range. Two types of targets were experimentally investigated: low-density iron oxide aerogels (density 6-16 mg/cm{sup 3}) and stainless steel foil-lined cavity targets (steel thickness 1-5 {mu}m). The targets were irradiated by 40 beams of the OMEGA laser (500 J/beam, 1 ns pulse, wavelength 351 nm). All targets showed good coupling with the laser, with <5% of the incident laser light backscattered by the resulting plasma in all cases (typically <2.5%). The aerogel targets produced T{sub e}=2 to 3 keV, n{sub e}=0.12-0.2 critical density plasmas yielding a 40%-60% laser-to-x-ray total conversion efficiency (CE) (1.2%-3% in the Fe K-shell range). The foil cavity targets produced T{sub e}{approx} 2 keV, n{sub e}{approx} 0.15 critical density plasmas yielding a 60%-75% conversion efficiency (1.6%-2.2% in the Fe K-shell range). Time-resolved images illustrate that the volumetric heating of low-density aerogels allow them to emit a higher K-shell x-ray yield even though they contain fewer Fe atoms. However, their challenging fabrication process leads to a larger shot-to-shot variation than cavity targets.
Perez, F.; Kay, J. J.; Patterson, J. R.; Kane, J.; May, M.; Emig, J.; Colvin, J.; Gammon, S.; Satcher, J. H. Jr.; Fournier, K. B. [Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550 (United States); Villette, B.; Girard, F.; Reverdin, C. [CEA DAM DIF, F-91297 Arpajon (France); Sorce, C. [Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550 (United States); University of Rochester - Laboratory for Laser Energetics, 250 E. River Rd, Rochester, New York 14623-1299 (United States); Jaquez, J. [General Atomics, San Diego, California 92121 (United States)
Modeling energy dependence of the inner-shell x-ray emission produced by femtosecond-pulse laser irradiation of xenon clusters
We employ the Los Alamos suite of atomic physics codes to model the inner-shell x-ray emission spectrum of xenon and compare results with those obtained via high-resolution x-ray spectroscopy of xenon clusters irradiated by 30 fs Ti:Sa laser pulses. We find that the commonly employed configuration average approximation breaks down and significant spin-orbit splitting necessitates a detailed level accounting. Additionally, we reproduce an interesting spectral trend for a series of experimental spectra taken with varying pulse energy for fixed pulse duration. To simulate the experimental measurements at increasing beam energies, we find that spectral modeling requires an increased hot electron fraction, but decreased atomic density and bulk electron temperature. We believe these latter conditions to be a result of partial cluster destruction due to the increased energy in the laser prepulse.
Colgan, James P [Los Alamos National Laboratory
Particle Formation from Pulsed Laser Irradiation of SootAggregates studied with scanning mobility particle sizer, transmissionelectron microscope and near-edge x-ray absorption fine structure.
We investigated the physical and chemical changes induced in soot aggregates exposed to laser radiation using a scanning mobility particle sizer, a transmission electron microscope, and a scanning transmission x-ray microscope to perform near-edge x-ray absorption fine structure spectroscopy. Laser-induced nanoparticle production was observed at fluences above 0.12 J/cm(2) at 532 nm and 0.22 J/cm(2) at 1064 nm. Our results indicate that new particle formation proceeds via (1) vaporization of small carbon clusters by thermal or photolytic mechanisms, followed by homogeneous nucleation, (2) heterogeneous nucleation of vaporized carbon clusters onto material ablated from primary particles, or (3) both processes.
Michelsen, Hope A.; Tivanski, Alexei V.; Gilles, Mary K.; vanPoppel, Laura H.; Dansson, Mark A.; Buseck, Peter R.; Buseck, Peter R.
X-ray Synchrotron Radiation in a Plasma Wiggler
A relativistic electron beam can radiate due to its betatron motion inside an ion channel. The ion channel is induced by the electron bunch as it propagates through an underdense plasma. In the theory section of this thesis the formation of the ion channel, the trajectories of beam electrons inside the ion channel, the radiation power and the radiation spectrum of the spontaneous emission are studied. The comparison between different plasma wiggler schemes is made. The difficulties in realizing stimulated emission as the beam traverses the ion channel are investigated, with particular emphasis on the bunching mechanism, which is important for the ion channel free electron laser. This thesis reports an experiment conducted at the Stanford Linear Accelerator Center (SLAC) to measure the betatron X-ray radiations for the first time. They first describe the construction and characterization of the lithium plasma source. In the experiment, the transverse oscillations of the SLAC 28.5 GeV electron beam traversing through a 1.4 meter long lithium plasma source are clearly seen. These oscillations lead to a quadratic density dependence of the spontaneously emitted betatron X-ray radiation. The divergence angle of the X-ray radiation is measured. The absolute photon yield and the spectral brightness at 14.2 KeV photon energy are estimated and seen to be in reasonable agreement with theory.
Wang, Shuoquin; /UCLA /SLAC, SSRL
Relative x-ray backlighter intensity comparison of ti and ti/sc combination foils driven in double-sided and single-sided laser configuration
Use of multiple backlighter foils and/or double-sided laser interaction geometry with backlit imaging can result in improved backlighter efficiency. An experimental comparison of backlighter intensity for Ti foils and Ti/Sc combination foils in both the one-sided and double-sided laser-interaction configuration is presented. Spectrally-integrated framing camera images show intensity contributions of front and rear backlighter surfaces for both foil types. Analysis of time-resolved x-ray spectra collected from foil targets show the relative contribution of Ti and Sc 2-1 He-like resonance lines to the total backlighter intensity.
Bullock, A B; Landen, O L; Bradley, D K
Soft x-ray laser using pumping of 3P and 4P levels of He-like and H-like ions
X-ray laser method and apparatus for producing coherent radiation at, for example, energies of 40 to 189 eV, using Be-like Cr, N-like Ni, He-like Na, B-like Cr, Be-like Mn or similar multiply ionized species to pump appropriate high energy transitions in He-like or H-like rare gases or N, O, F, or C gases, with associated laser transition gains of 20 to 50 cm/sup -1/.
Hagelstein, P.
X-ray laser method and apparatus are disclosed for producing coherent radiation at, for example, energies of at least 40 eV, using Be-like Cr, N-like Ni, He-like Na, B-like Cr, Be-like Mn or similar multiply ionized species to pump appropriate high energy transitions in He-like or H-like N, O, F, C or rare gases, with associated laser transition gains of 4-50 cm[sup [minus]1]. 8 figs.
Design of a superconducting linear accelerator for an Infrared Free Electron Laser of the proposed Chemical Dynamics Research Laboratory at LBL
An accelerator complex has recently been designed at LBL as part of an Infrared Free Electron Laser facility in support of a proposed Chemical Dynamics Research Laboratory. We will outline the choice of parameters and design philosophy, which are strongly driven by the demand of reliable and spectrally stable operation of the FEL for very special scientific experiments. The design is based on a 500 MHz recirculating superconducting electron linac with highest energy reach of about 60 MeV. The accelerator is injected with beams prepared by a specially designed gun-buncher system and incorporates a near-isochronous and achromatic recirculation line tunable over a wide range of beam energies. The stability issues considered to arrive at the specific design will be outlined.
Chattopadhyay, S.; Byrns, R.; Donahue, R.; Edighoffer, J.; Gough, R.; Hoyer, E.; Kim, K.J.; Leemans, W.; Staples, J.; Taylor, B.; Xie, M.
In-line phase-contrast imaging of a biological specimen using a compact laser-Compton scattering-based x-ray source
Laser-Compton scattering (LCS) x-ray sources have recently attracted much attention for their potential use at local medical facilities because they can produce ultrashort pulsed, high-brilliance, and quasimonochromatic hard x rays with a small source size. The feasibility of in-line phase-contrast imaging for a 'thick' biological specimens of rat lumbar vertebrae using the developed compact LCS-X in AIST was investigated for the promotion of clinical imaging. In the higher-quality images, anatomical details of the spinous processes of the vertebrae are more clearly observable than with conventional absorption radiography. The results demonstrate that phase-contrast radiography can be performed using LCS-X.
Ikeura-Sekiguchi, H.; Kuroda, R.; Yasumoto, M.; Toyokawa, H.; Koike, M.; Yamada, K. [National Institute of Advanced Industrial Science and Technology (AIST), Central 2-5, 1-1-1 Umezono, Tsukuba, Ibaraki 305-8568 (Japan); Sakai, F. [Sumitomo Heavy Industries, Ltd. (SHI), 2-1-1, Yatocho, Nishitokyo, Tokyo 188-8585 (Japan); Mori, K.; Maruyama, K. [Ibaraki Prefectural University of Health Sciences, 4669-2, Ami, Inashiki, Ibaraki 300-0394 (Japan); Oka, H.; Kimata, T. [St. Marianna University School of Medicine, 2-16-1, Sugao, Miyamae-ku, Kawasaki City 216-8512 (Japan)
X-ray grating spectrometer for opacity measurements in the 50 eV to 250 eV spectral range at the LULI 2000 laser facility
An x-ray grating spectrometer was built in order to measure opacities in the 50 eV to 250 eV spectral range with an average spectral resolution {approx} 50. It has been used at the LULI-2000 laser facility at Ecole Polytechnique (France) to measure the {Delta}n = 0, n = 3 transitions of several elements with neighboring atomic number: Cr, Fe, Ni, and Cu in the same experimental conditions. Hence a spectrometer with a wide spectral range is required. This spectrometer features one line of sight looking through a heated sample at backlighter emission. It is outfitted with one toroidal condensing mirror and several flat mirrors cutting off higher energy photons. The spectral dispersion is obtained with a flatfield grating. Detection consists of a streak camera sensitive to soft x-ray radiation. Some experimental results showing the performance of this spectrometer are presented.
Reverdin, Charles; Caillaud, T.; Gilleron, F.; Pain, J. C.; Silvert, V.; Soullie, G.; Villette, B. [CEA, DAM, DIF, 91297 Arpajon (France); Thais, Frederic; Loisel, Guillaume; Blenski, T.; Poirier, M. [CEA, DSM, IRAMIS, Service Photons, Atomes et Molecules, 91191 Gif-sur-Yvette (France); Busquet, M. [ARTEP Inc, Ellicott City, Maryland 21042 (United States); Bastiani-Ceccotti, S.; Serres, F. [LULI, Ecole Polytechnique, CNRS, CEA, UPMC, route de Saclay, 91128 Palaiseau (France); Ducret, J. E. [CELIA, UMR5107, CEA, CNRS, Universite de Bordeaux, 33400 Talence (France); Foelsner, W. [Max Planck Instituet fuer Quantum Optik, 85748 Garching (Germany); Gilles, D.; Turck-Chieze, S. [CEA, DSM, IRFU, Service d'astrophysique, 91191 Gif-sur-Yvette (France)
Electron beam-based sources of ultrashort x-ray pulses.
A review of various methods for generation of ultrashort x-ray pulses using relativistic electron beam from conventional accelerators is presented. Both spontaneous and coherent emission of electrons is considered. The importance of the time-resolved studies of matter at picosecond (ps), femtosecond (fs), and atttosecond (as) time scales using x-rays has been widely recognized including by award of a Nobel Prize in 1999 [Zewa]. Extensive reviews of scientific drivers can be found in [BES1, BES2, BES3, Lawr, Whit]. Several laser-based techniques have been used to generate ultrashort x-ray pulses including laser-driven plasmas [Murn, Alte, Risc, Rose, Zamp], high-order harmonic generation [Schn, Rund, Wang, Arpi], and laser-driven anode sources [Ande]. In addition, ultrafast streak-camera detectors have been applied at synchrotron sources to achieve temporal resolution on the picosecond time scale [Wulf, Lind1]. In this paper, we focus on a different group of techniques that are based on the use of the relativistic electron beam produced in conventional accelerators. In the first part we review several techniques that utilize spontaneous emission of electrons and show how solitary sub-ps x-ray pulses can be obtained at existing storage ring based synchrotron light sources and linacs. In the second part we consider coherent emission of electrons in the free-electron lasers (FELs) and review several techniques for a generation of solitary sub-fs x-ray pulses. Remarkably, the x-ray pulses that can be obtained with the FELs are not only significantly shorter than the ones considered in Part 1, but also carry more photons per pulse by many orders of magnitude.
Zholents, A.; Accelerator Systems Division (APS)
2011 X-Ray Science Gordon Research Conference (August 7-12, 2011, Colby, College. Waterville, ME)
The 2011 Gordon Research Conference on X-ray Science will feature forefront x-ray-based science enabled by the rapid improvements in synchrotron and x-ray laser sources. Across the world, x-ray sources are playing an increasingly important role in physics, materials, chemistry, and biology, expanding into ever broadening areas of science and engineering. With the first hard x-ray free electron laser source beginning operation and with other advanced x-ray sources operational and planned, it is a very exciting and pivotal time for exchange ideas about the future of x-ray science and applications. The Conference will provide the forum for this interaction. An international cast of speakers will illuminate sessions on ultrafast science, coherence, imaging, in situ studies, extreme conditions, new developments in optics, sources, and detectors, inelastic scattering, nanoscience, life science, and energy sciences. The Conference will bring together investigators at the forefront of these areas, and will provide a venue for young scientists entering a career in x-ray research to present their research in poster format, hold discussions in a friendly setting, and exchange ideas with leaders in the field. Some poster presenters will be selected for short talks. The collegial atmosphere of this Conference, with ample time for discussion as well as opportunities for informal gatherings in the afternoons and evenings, will provide an avenue for scientists from different disciplines to exchange ideas about forefront x-ray techniques and will promote cross-fertilization between the various research areas represented.
Gregory Stephenson
The ALS X-Ray Streak Camera: Bringing the Ultrafast and Ultrasmall into
The ALS X-Ray Streak Camera: Bringing the Ultrafast and Ultrasmall into Focus Print The ALS X-Ray Streak Camera: Bringing the Ultrafast and Ultrasmall into Focus Print Studying the world of the ultrasmall and the ultrafast is at the frontier of scientific research. Two x-ray approaches can be used for ultrafast examinations. The first entails developing sources that have short x-ray pulses such as free-electron lasers and slicing sources, which will provide the ultrafast temporal information. The other approach is to develop a detector that is fast enough to resolve the ultrafast details of the dynamical processes. ALS researchers are taking the second path but adding a spatial resolution capability; that is, they are developing a high-speed x-ray streak camera with high spatial resolution to watch, in real time, the motion of the atoms in materials. So far, a temporal resolution of 233 fs and a spatial resolution of 10 mm have been demonstrated. This is the first time that such a high temporal resolution has been combined with high spatial resolution in a streak camera.
A recirculating linac-based facility for ultrafast X-ray science
We present an updated design for a proposed source of ultra-fast synchrotron radiation pulses based on a recirculating superconducting linac, in particular the incorporation of EUV and soft x-ray production. The project has been named LUX - Linac-based Ultrafast X-ray facility. The source produces intense x-ray pulses with duration of 10-100 fs at a 10 kHz repetition rate, with synchronization of 10 s fs, optimized for the study of ultra-fast dynamics. The photon range covers the EUV to hard x-ray spectrum by use of seeded harmonic generation in undulators, and a specialized technique for ultra-short-pulse photon production in the 1-10 keV range. High-brightness rf photocathodes produce electron bunches which are optimized either for coherent emission in free-electron lasers, or to provide a large x/y emittance ration and small vertical emittance which allows for manipulation to produce short-pulse hard x-rays. An injector linac accelerates the beam to 120 MeV, and is followed by four passes through a 600-720 MeV recirculating linac. We outline the major technical components of the proposed facility.
Corlett, J.N; Barletta, W.A.; DeSantis, S.; Doolittle, L.; Fawley, W.M.; Green, M.A.; Heimann, P.; Leone, S.; Lidia, S.; Li, D.; Ratti, A.; Robinson, K.; Schoenlein, R.; Staples, J.; Wan, W.; Wells, R.; Wolski, A.; Zholents, A.; Placidi, M.; Pirkl, W.; Parmigiani, F.
Kinematics of Compton backscattering x-ray source for angiography
Calculations of X-Ray production rates, energy spread, and spectrum of Compton-backscattered photons from a Free Electron Laser on an electron beam in a low energy (136-MeV) compact (8.5-m circumference) storage ring indicate that an X-Ray intensity of 34.6 10{sup 7} X-Ray photons per 0.5-mm {times} 0.5-mm pixel for Coronary Angiography near the 33.169-keV iodine K-absorption edge can be achieved in a 4-msec pulse within a scattering cone of 1-mrad half angle. This intensity, at 10-m from the photon-electron interaction point to the patient is about a factor of 10 larger than presently achieved from a 4.5-T superconducting wiggler source in the NSLS 2.5-GeV storage ring and over an area about 5 times larger. The 2.2-keV energy spread of the Compton-backscattered beam is, however, much larger than the 70-eV spread presently attained form the wiggler source and use of a monochromator. The beam spot at the 10-m interaction point-to-patient distance is 20-mm diameter; larger spots are attainable at larger distances but with a corresponding reduction in X-Ray flux. Such a facility could be an inexpensive clinical alternative to present methods of non-invasive Digital Subtraction Angiography (DSA), small enough to be deployed in an urban medical center, and could have other medical, industrial and aerospace applications. Problems with the Compton backscattering source include laser beam heating of the mirror in the FEL oscillator optical cavity, achieving a large enough X-Ray beam spot at the patient, and obtaining radiation damping of the transverse oscillations and longitudinal emittance dilution of the storage ring electron beam resulting from photon-electron collisions without going to higher electron energy where the X-Ray energy spread becomes excessive for DSA. 38 refs.
Blumberg, L.N.
Superlattices and Microstructures, Vol. 21, No. 2, 1997 Free electron laser saturation spectroscopy of neutral donors and
for several FEL laser power densities at 12 K. Saturation of the D0 1s-2p+ transition and CR is observable in which an electron excited into the 2p+ state (rate X0) may either relax directly back to the 1s ground state (rate 0), or may be transferred directly to the N = 0 Landau level (LL) (rate X1 times
Kono, Junichiro
Transverse Coherence of the LCLS X-Ray Beam
Self-amplifying spontaneous radiation free-electron lasers, such as the LCLS or the European X-FEL, rely on the incoherent, spontaneous radiation as the seed for the amplifying process. Though this method overcomes the need for an external seed source one drawback is the incoherence of the effective seed signal. The FEL process allows for a natural growth of the coherence because the radiation phase information is spread out within the bunch due to slippage and diffraction of the radiation field. However, at short wavelengths this spreading is not sufficient to achieve complete coherence. In this presentation we report on the results of numerical simulations of the LCLS X-ray FEL. From the obtained radiation field distribution the coherence properties are extracted to help to characterize the FEL as a light source.
An experiment to demonstrate a nitrogen recombination X-ray amplifier using high-density planar gas jet laser target. Final report
The results of an experiment to search for lasing in atomic transitions at x-ray energies in N{sub 2} gas target plasmas using ultra-short laser pulses is presented. Particular emphasis was placed on a search for a predicted 24.7 nm optical-field-ionization (OFI) induced lasing line from the Li-like nitrogen (N{sup 4+}, 3d {yields} 2p) transition. The excitation laser was a multi-terawatt Cr:LiSrAlF{sub 6} laser system operating at a wavelength of 825 nm and a pulse duration of 135 fs located at the Lawrence Livermore National Laboratory. Experimental conditions were optimized and a series of Li-like (including the 24.7 rm N{sup 4+} 3d {yields} 2p) lines were observed and identified. Further experimental studies are required before an attempt at measurement of any potential lasing gain can be made.
Pronko, J.G.; Kohler, D.
Time-resolved x-ray imaging of high-power laser-irradiated under-dense silica aerogels and agar foams
This paper presents the results of experiments in which a high-power laser was used to irradiate low density (4 - 9 mg/cm{sup 3}) silica aerogel and agar foam targets. The laser-solid interaction and energy transport through the material were monitored with time-resolved imaging diagnostics, and the data show the production and propagation of an x-ray emission front in the plasma. The emission-front trajectory data are found to be in significant disagreement with detailed simulations, which predict a much more rapid heating of the cold material, and the data suggest that this discrepancy is not explainable by target inhomogeneities. Evidence suggests that energy transport into the cold material may be dominated by thermal conduction; however, no completely satisfactory explanation for the discrepancies is identified, and further experimental and theoretical research is necessary in order to resolve this important problem in laser-plasma interaction physics.
Koch, J.A.; Estabrook, K.G.; Bauer, J.D. [and others
Optimization for Single-Spike X-Ray FELs at LCLS with a Low Charge Beam
The Linac Coherent Light Source is an x-ray free-electron laser at the SLAC National Accelerator Laboratory, which is operating at x-ray wavelengths of 20-1.2 Angstrom with peak brightness nearly ten orders of magnitude beyond conventional synchrotron radiation sources. At the low charge operation mode (20 pC), the x-ray pulse length can be LCLS), the world's first hard x-ray Free electron laser (FEL), has started operation since 2009. With nominal operation charge of 250 pC, the generated x-ray pulse length is from 70 fs to a few hundred fs. This marks the beginning of a new era of ultrashort x-ray sciences. In addition, a low charge (20pC) operation mode has also been established. Since the collective effects are reduced at the low charge mode, we can increase the compression factor and still achieve a few kA peak current. The expected electron beam and x-ray pulses are less than 10 fs. There are growing interests in even shorter x-ray pulses, such as fs to sub-fs regime. One of the simple solutions is going to even lower charge. As discussed, single-spike x-ray pulses can be generated using 1 pC charge. However, this charge level is out of the present LCLS diagnostic range. 20 pC is a reasonable operation charge at LCLS, based on the present diagnostic system. At 20 pC in the soft x-ray wavelength regime, we have experimentally demonstrated that FEL can work at undercompression or over-compression mode, such as 1 degree off the full-compression; at full-compression, however, there is almost no lasing. In hard x-ray wavelength regime, we observed that there are reasonable photons generated even at full-compression mode, although the photon number is less than that from under-compression or over-compression mode. Since we cannot measure the x-ray pulse length at this time scale, the machine is typically optimized for generating maximum photons, not minimum pulse length. In this paper, we study the methods of producing femtosecond (or single-spike) x-ray pulses at LCLS with 20 pC charge, based on start-to-end simulations. Figure 1 shows a layout of LCLS. The compression in the second bunch compressor (BC2) determines the final e-beam bunch length. However, the laser heater, dog-leg after the main linac (DL2) and collective effects also affect the final bunch length. To adjust BC2 compression, we can either change the L2 phase or BC2 R{sub 56}. In this paper we only tune L2 phase while keep BC2 R{sub 56} fixed. For the start-to-end simulations, we used IMPACT-T and ELEGANT tracking from the photocathode to the entrance of the undulator, after that the FEL radiation was simulated with GENESIS. IMPACT-T tracks about 10{sup 6} particles in the injector part until 135 MeV, including 3D space charge force. The output particles from IMPACT-T are smoothed and increased to 12 x 10{sup 6} to reduce high-frequency numerical noise for subsequent ELEGANT simulations, which include linear and nonlinear transport effects, a 1D transient model of CSR, and longitudinal space charge effects, as well as geometric and resistive wake fields in the accelerator. In GENESIS part, the longitudinal wake field from undulator chamber and longitudinal space field are also included.
Wang, L.; Ding, Y.; Huang, Z.; /SLAC
X-ray Thomson scattering for partially ionized plasmas including the effect of bound levels
X-ray Thomson scattering is being developed as a method to measure the temperature, electron density, and ionization state of high energy density plasmas such as those used in inertial confinement fusion. Most experiments are currently done at large laser facilities that can create bright X-ray sources, however the advent of the X-ray free electron laser (X-FEL) provides a new bright source to use in these experiments. One challenge with X-ray Thomson scattering experiments is understanding how to model the scattering for partially ionized plasmas in order to include the contributions of the bound electrons in the scattered intensity. In this work we take the existing models of Thomson scattering that include elastic ion-ion scattering and the electron-electron plasmon scattering and add the contribution of the bound electrons in the partially ionized plasmas. We validated our model by analyzing existing beryllium experimental data. We then consider several higher Z materials such as Cr and predict the existe...
Nilsen, J; Cheng, K T
Transient x-ray diffraction and its application to materials science and x-ray optics
Time resolved x-ray diffraction and scattering have been applied to the measurement of a wide variety of physical phenomena from chemical reactions to shock wave physics. Interest in this method has heightened in recent years with the advent of versatile, high power, pulsed x-ray sources utilizing laser plasmas, electron beams and other methods. In this article, we will describe some of the fundamentals involved in time resolved x-ray diffraction, review some of the history of its development, and describe some recent progress in the field. In this article we will emphasize the use of laser-plasmas as the x-ray source for transient diffraction.
Hauer, A.A.; Kopp, R.; Cobble, J.; Kyrala, G.; Springer, R. [and others
Computer analysis of four channel x-ray microscopy images to obtain source and spectral emission data on laser fusion
It is possible to analyze the images obtained from the four- channel x- ray microscope to obtain reasonable estimates of source spatial and energy emission. The technique shown here is particularly useful when relative comparisons are desired in which, from shot to shot, few parameters are changed. These data are of use in fuel pellet design and in checking design code predictions. The technique should also apply to pinhole camera data. Largest uncertainties appear to be due to film energy/handling calibration and mirror efficiency measurements. (auth)
Harper, T.L.
Effects of finite beam and plasma temperature on the growth rate of a two-stream free electron laser with background plasma
A fluid theory is used to derive the dispersion relation of two-stream free electron laser (TSFEL) with a magnetic planar wiggler pump in the presence of background plasma (BP). The effect of finite beams and plasma temperature on the growth rate of a TSFEL has been verified. The twelve order dispersion equation has been solved numerically. Three instabilities, FEL along with the TS and TS-FEL instabilities occur simultaneously. The analysis in the case of cold BP shows that when the effect of the beam temperature is taken into account, both instable bands of wave-number and peak growth rate in the TS instability increase, but peak growth of the FEL and TS-FEL instabilities decreases. Thermal motion of the BP causes to diminish the TS instability and it causes to decrease the FEL and TS-FEL instabilities. By increasing the beam densities and lowering initial velocities (in the collective Raman regime), growth rate of instabilities increases; however, it has opposite behavior in the Campton regime.
Mahdizadeh, N. [Department of Physics, Sabzevar Branch, Islamic Azad University, Sabzevar (Iran, Islamic Republic of); Aghamir, F. M. [Department of Physics, University of Tehran, Tehran (Iran, Islamic Republic of)
X-Ray Topography
Sep 17, 2009 ... Stress Mapping Analysis by Ray Tracing (SMART): A New Technique ... technique of synchrotron X-ray topography, where a grid made out of�...
Spectral linewidth of a Ne-like Ar capillary discharge soft x-ray laser and its dependence on amplification beyond gain-saturation
We report the measurement of the linewidth and temporal coherence of a = 46.9 nm neon-like argon capillary discharge soft x-ray laser and its variation with plasma column length. A wavefront division interferometer was used to resolve the 3p 1S0-3s 1P1 laser line, resulting in a measured relative linewidths of / = 3-4 10 -5. The measurements do not observe saturation re-broadening as this clearly dominantly Doppler-broadened inhomogeneous line is amplified beyond the intensity corresponding to gain saturation. Model simulations indicate that this is the result of comparatively small collisional broadening that homogenizes the line profile to practically eliminate inhomogeneous saturation re-broadening. Collisional re-distribution is computed to only play a minor role in homogenizing the line profile.
Urbanski, Lukasz [Colorado State University, Fort Collins; Marconi, Mario [Colorado State University, Fort Collins; Meng, L. M. [Colorado State University, Fort Collins; Berrill, Mark A [ORNL; Guilbaud, O. [Universite Paris Sud, Orsay, France; Klisnick, Annie [Universite Paris Sud, Orsay, France; Rocca, Jorge [Colorado State University, Fort Collins
X-ray crystal spectrometer for opacity measurements in the 8-18 A spectral range at the LULI laser facility
An x-ray crystal spectrometer was built in order to measure opacities in the 8-18 A spectral range with an average spectral resolution of <{lambda}/{delta}{lambda}>{approx}400. It has been successfully used at the LULI-2000 laser facility (See C. Sauteret, rapport LULI 2001, 88 (2002) at Ecole Polytechnique (France) to measure in the same experimental conditions the 2p-3d transitions of several elements with the neighboring atomic number Z: Fe, Ni, Cu, and Ge [G. Loisel et al., High Energy Density Phys. 5, 173 (2009)]. Hence, a spectrometer with a wide spectral range is needed. This spectrometer features two lines of sight. In this example, one line of sight looks through the sample and the other one is looking directly at the backlighter emission. Both are outfitted with a spherical condensing mirror. A TlAP crystal is used for spectral dispersion. Detection is made with an image plate Fuji BAS TR2025, which is sensitive to x rays. We present some experimental results showing the performances of this spectrometer.
Reverdin, C. [CEA-DAM-DIF, F-91297 Arpajon (France); Thais, F.; Loisel, G.; Bougeard, M. [CEA-DSM-IRAMIS, F-91191 Gif-sur-Yvette (France)
Availability Performance and Considerations for LCLS X-Ray FEL at SLAC
The Linac Coherent Light Source (LCLS) is an X-ray Free Electron Laser (FEL) facility located at the SLAC National Accelerator Laboratory. LCLS has been in operation since spring 2009, and it has completed its 3rd user run. LCLS is the first in its class of X-ray FEL user facilities, and presents different availability challenges compared to storage ring light sources. This paper presents recent availability performance of the FEL as well as factors to consider when defining the operational availability figure of merit for user runs. During LCLS [1] user runs, an availability of 95% has been set as a goal. In run III, LCLS photon and electron beam systems achieved availabilities of 94.8% and 96.7%, respectively. The total availability goal can be distributed among subsystems to track performance and identify areas that need attention in order to maintain and improve hardware reliability and operational availability. Careful beam time accounting is needed to understand the distribution of down time. The LCLS complex includes multiple experimental hutches for X-ray science, and each user program has different requirements of a set of parameters that the FEL can be configured to deliver. Since each user may have different criteria for what is considered 'acceptable beam', the quality of the beam must be considered to determine the X-ray beam availability.
Allen, W. B.
Real-Space x-ray tomographic reconstruction of randomly oriented objects with sparse data frames
Schemes for X-ray imaging single protein molecules using new x-ray sources, like x-ray free electron lasers (XFELs), require processing many frames of data that are obtained by taking temporally short snapshots of identical molecules, each with a random and unknown orientation. Due to the small size of the molecules and short exposure times, average signal levels of much less than 1 photon/pixel/frame are expected, much too low to be processed using standard methods. One approach to process the data is to use statistical methods developed in the EMC algorithm (Loh & Elser, Phys. Rev. E, 2009) which processes the data set as a whole. In this paper we apply this method to a real-space tomographic reconstruction using sparse frames of data (below $10^{-2}$ photons/pixel/frame) obtained by performing x-ray transmission measurements of a low-contrast, randomly-oriented object. This extends the work by Philipp et al. (Optics Express, 2012) to three dimensions and is one step closer to the single molecule recons...
Ayyer, Kartik; Tate, Mark W; Elser, Veit; Gruner, Sol M
X-ray phase contrast imaging of biological specimens with femtosecond pulses of betatron radiation from a compact laser plasma wakefield accelerator
We show that x-rays from a recently demonstrated table top source of bright, ultrafast, coherent synchrotron radiation [Kneip et al., Nat. Phys. 6, 980 (2010)] can be applied to phase contrast imaging of biological specimens. Our scheme is based on focusing a high power short pulse laser in a tenuous gas jet, setting up a plasma wakefield accelerator that accelerates and wiggles electrons analogously to a conventional synchrotron, but on the centimeter rather than tens of meter scale. We use the scheme to record absorption and phase contrast images of a tetra fish, damselfly and yellow jacket, in particular highlighting the contrast enhancement achievable with the simple propagation technique of phase contrast imaging. Coherence and ultrafast pulse duration will allow for the study of various aspects of biomechanics.
Kneip, S. [Blackett Laboratory, Imperial College London, London SW7 2AZ (United Kingdom); Center for Ultrafast Optical Science, University of Michigan, Ann Arbor 48109 (United States); McGuffey, C.; Dollar, F.; Chvykov, V.; Kalintchenko, G.; Krushelnick, K.; Maksimchuk, A.; Mangles, S. P. D.; Matsuoka, T.; Schumaker, W.; Thomas, A. G. R.; Yanovsky, V. [Center for Ultrafast Optical Science, University of Michigan, Ann Arbor 48109 (United States); Bloom, M. S.; Najmudin, Z.; Palmer, C. A. J.; Schreiber, J. [Blackett Laboratory, Imperial College London, London SW7 2AZ (United Kingdom)
High Average Power, 100 Hz Repetition Rate, Table-top EUV/Soft X-ray Lasers
Compact =13.9 nm and =18.9 nm lasers with >0.1 mW average power at 100 Hz repetition rate driven by a diode-pumped, 1 J, CPA laser were demonstrated. Wavelength scaling to =10.9 nm will be discussed.
Reagan, Brendon [Colorado State University, Fort Collins; Wernsing, Keith [Colorado State University, Fort Collins; Baumgarten, Cory [Colorado State University, Fort Collins; Durivage, Leon [Colorado State University, Fort Collins; Berrill, Mark A [ORNL; Furch, Federico [Colorado State University, Fort Collins; Curtis, Alden [Colorado State University, Fort Collins; Salsbury, Chase [Colorado State University, Fort Collins; Luther, Brad [Colorado State University, Fort Collins; Patel, Dinesh [Colorado State University, Fort Collins; Menoni, Carmen [Colorado State University, Fort Collins; Rocca, Jorge [Colorado State University, Fort Collins
Cross calibration of AGFA-D7 x-ray film against direct exposure film from 2 to 8.5 keV using laser generated x-rays
Direct exposure film (DEF) is being discontinued. DEF film has been the workhorse in inertial confinement fusion (ICF) research and is used to record x-ray images and spectra. A previous search for a replacement [K. M. Chandler et al., Rev. Sci. Instrum. 76, 113111 (2005)] did not consider AGFA film. We present comparisons using the results of measurements using AGFA-D7 film, XAR, TMG, and Biomax-MS films in the same spectrometer recording a gold spectrum in the 2-4 keV range and the iron spectrum in the 5-8.5 keV range. AGFA film was found to have some unique properties useful in x-ray spectroscopy and imaging, especially when signal strength is not a concern.
Kyrala, George A. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)
Compton backscattered collimated x-ray source
A high-intensity, inexpensive and collimated x-ray source for applications such as x-ray lithography is disclosed. An intense pulse from a high power laser, stored in a high-finesse resonator, repetitively collides nearly head-on with and Compton backscatters off a bunched electron beam, having relatively low energy and circulating in a compact storage ring. Both the laser and the electron beams are tightly focused and matched at the interaction region inside the optical resonator. The laser-electron interaction not only gives rise to x-rays at the desired wavelength, but also cools and stabilizes the electrons against intrabeam scattering and Coulomb repulsion with each other in the storage ring. This cooling provides a compact, intense bunch of electrons suitable for many applications. In particular, a sufficient amount of x-rays can be generated by this device to make it an excellent and flexible Compton backscattered x-ray (CBX) source for high throughput x-ray lithography and many other applications.
Ruth, Ronald D. (Woodside, CA); Huang, Zhirong (Stanford, CA)
Compton backscattered collmated X-ray source
Gamma Radiation & X-Rays
Gamma Radiation and X-Rays 1. Gamma radiation and X-rays are electromagnetic radiation like visible light, radio waves, and ultraviolet light. These electromagnetic radiations...
Ultra-short wavelength x-ray system
A method and apparatus to generate a beam of coherent light including x-rays or XUV by colliding a high-intensity laser pulse with an electron beam that is accelerated by a synchronized laser pulse. Applications include x-ray and EUV lithography, protein structural analysis, plasma diagnostics, x-ray diffraction, crack analysis, non-destructive testing, surface science and ultrafast science.
Umstadter, Donald (Ann Arbor, MI); He, Fei (Ann Arbor, MI); Lau, Yue-Ying (Potomac, MD)
High resolution soft x-ray spectroscopy of low Z K-shell emission from laser-produced plasmas
A large radius, R = 44.3 m, High Resolution Grating Spectrometer (HRGS) with 2400 line/mm variable line spacing has been designed for laser-produced plasma experiments conducted at the Lawrence Livermore National Laboratory Jupiter Laser Facility. The instrument has been run with a low-noise, charge-coupled device detector to record high signal-to-noise spectra in the 10-50 {angstrom} wavelength range. The instrument can be run with a 10-20 {micro}m wide slit to achieve the best spectral resolving power, approaching 1000 and similar to crystal spectrometers at 12-20 {angstrom}, or in slitless operation with a small symmetrical emission source. We describe preliminary spectra emitted from various H-like and He-like low Z ion plasmas heated by 100-500 ps (FWHM), 527 nm wavelength laser pulses. This instrument can be developed as a useful spectroscopy platform relevant to laboratory-based astrophysics as well as high energy density plasma studies.
Dunn, J; Magee, E W; Shepherd, R; Chen, H; Hansen, S B; Moon, S J; Brown, G V; Gu, M; Beiersdorfer, P; Purvis, M A
X-ray microtomography
In this tutorial, we describe X-ray microtomography as a technique to nondestructively characterize material microstructure in three dimensions at a micron level spatial resolution. While commercially available laboratory scale instrumentation is available, we focus our attention on synchrotron-based systems, where we can exploit a high flux, monochromatic X-ray beam to produce high fidelity three-dimensional images. A brief description of the physics and the mathematical analysis behind the technique is followed by example applications to specific materials characterization problems, with a particular focus on the utilization of three-dimensional image processing that can be used to extract a wide range of useful information.
Landis, Eric N., E-mail: email@example.com [Department of Civil and Environmental Engineering, University of Maine, 5711 Boardman Hall, Orono, Maine 04469 (United States); Keane, Denis T., E-mail: firstname.lastname@example.com [Department of Materials Science and Engineering, Northwestern University (United States); DND-CAT, Advanced Photon Source, Argonne National Laboratory, Bldg. 432/A002, 9700 S. Cass Ave, Argonne, Illinois 60439 (United States)
The Coherent X-ray Imaging (CXI) Instrument at the Linac Coherent Light Source (LCLS)
The Linac Coherent Light Source (LCLS) has become the first ever operational hard X-ray Free Electron Laser in 2009. It will operate as a user facility capable of delivering unique research opportunities in multiple fields of science. The LCLS and the LCLS Ultrafast Science Instruments (LUSI) construction projects are developing instruments designed to make full use of the capabilities afforded by the LCLS beam. One such instrument is being designed to utilize the LCLS coherent beam to image with high resolution any sub-micron object. This instrument is called the Coherent X-ray Imaging (CXI) instrument. This instrument will provide a flexible optical system capable of tailoring key beam parameters for the users. A suite of shot-to-shot diagnostics will also be provided to characterize the beam on every pulse. The provided instrumentation will include multi-purpose sample environments, sample delivery and a custom detector capable of collecting 2D data at 120 Hz. In this article, the LCLS will be briefly introduced along with the technique of Coherent X-ray Diffractive Imaging (CXDI). A few examples of scientific opportunities using the CXI instrument will be described. Finally, the conceptual layout of the instrument will be presented along with a description of the key requirements for the overall system and specific devices required.
Boutet, Sebastien
Dynamics and rheology under continuous shear flow studied by X-ray photon correlation spectroscopy
X-ray Photon Correlation Spectroscopy (XPCS) has emerged as a unique technique allowing the measurement of dynamics in materials on mesoscopic lengthscales. In particular, applications in soft matter physics cover a broad range of topics which include, but are not limited to, nanostructured materials such as colloidal suspensions or polymers, dynamics at liquid surfaces, membranes and interfaces, and the glass or gel transition. One of the most common problems associated with the use of bright X-ray beams with soft materials is beam induced radiation damage, and this is likely to become an even more limiting factor at future synchrotron and free electron laser sources. Flowing the sample during data acquisition is one of the simplest method allowing to limit the radiation damage. In addition to distributing the dose over many different scatterers, the method also enables new functionalities such as time-resolved studies in mixing cells. Here, we further develop an experimental technique that was recently proposed combining XPCS and continuously flowing samples. More specifically, we use a model system to show how the macroscopic advective response to flow and the microscopic dissipative dynamics (diffusion) can be quantified from the X-ray data. The method has many potential applications, e.g. dynamics of glasses and gels under continuous shear/flow, protein aggregations processes, the interplay between dynamics and rheology in complex fluids.
Andrei Fluerasu; Pawel Kwasniewski; Chiara Caronna; Fanny Destremaut; Jean-Baptiste Salmon; Anders Madsen
Ultra-Short Electron Bunch and X-Ray Temporal Diagnostics with an X-Band Transverse Deflector
The measurement of ultra-short electron bunches on the femtosecond time scale constitutes a very challenging problem. In X-ray free-electron laser facilities such as the Linac Coherent Light Source (LCLS), generation of sub-ten femtosecond X-ray pulses is possible, and some efforts have been put into both ultra-short electron and X-ray beam diagnostics. Here we propose a single-shot method using a transverse rf deflector (X-band) after the undulator to reconstruct both the electron bunch and X-ray temporal profiles. Simulation studies show that about 1 fs (rms) time resolution may be achievable in the LCLS and is applicable to a wide range of FEL wavelengths and pulse lengths. The jitter, resolution and other related issues will be discussed. The successful operation of the Linac Coherent Light Source (LCLS), with its capability of generating free-electron laser (FEL) X-ray pulses from a few femtoseconds (fs) up to a few hundred fs, opens up vast opportunities for studying atoms and molecules on this unprecedented ultrashort time scale. However, tremendous challenges remain in the measurement and control of these ultrashort pulses with femtosecond precision, for both the electron beam (e-beam) and the X-ray pulses. For ultrashort e-beam bunch length measurements, a standard method has been established at LCLS using an S-band radio-frequency (rf) deflector, which works like a streak camera for electrons and is capable of resolving bunch lengths as short as {approx} 10 fs rms. However, the e-beam with low charges of 20 pC at LCLS, which is expected to be less than 10 fs in duration, is too short to be measured using this transverse deflector. The measurement of the electron bunch length is helpful in estimating the FEL X-ray pulse duration. However, for a realistic beam, such as that with a Gaussian shape or even a spiky profile, the FEL amplification varies along the bunch due to peak current or emittance variation. This will cause differences between the temporal shape or duration of the electron bunch and the X-ray pulse. Initial experiments at LCLS have revealed that characterization of the X-ray pulse duration on a shot-by-shot basis is critical for the interpretation of the data. However, a reliable x-ray pulse temporal diagnostic tool is not available so far at the LCLS. We propose a novel method in this paper to characterize the FEL X-ray pulse duration and shape. A transverse rf deflector is used in conjunction with an e-beam energy spectrometer, located after the FEL undulator. By measuring the difference in the e-beam longitudinal phase space between FEL-on and FEL-off, we can obtain the time-resolved energy loss and energy spread induced from the FEL radiation, allowing the FEL X-ray temporal shape to be reconstructed.
Ding, Y.; Emma, P.; Frisch, J.; Huang, Z.; Loos, H.; Krejcik, P.; Wang, M-H.; /SLAC; Behrens, C.; /DESY
X-ray Security Screening
National and International Standards for X-ray Security Screening Applications. Summary: The primary objective of this ...
Tunable X-ray source
A method for the production of X-ray bunches tunable in both time and energy level by generating multiple photon, X-ray, beams through the use of Thomson scattering. The method of the present invention simultaneously produces two X-ray pulses that are tunable in energy and/or time.
Boyce, James R. (Williamsburg, VA)
Absorbed XFEL Dose in the Components of the LCLS X-Ray Optics
There is great concern that the short, intense XFEL pulse of the LCLS will damage the optics that will be placed into the beam. We have analyzed the extent of the problem by considering the anticipated materials and position of the optical components in the beam path, calculated the absorbed dose as a function of photon energy, and compared these doses with the expected doses required (i) to observe rapid degradation due to thermal fatigue, (ii) to reach the melting temperature, or (iii) to actually melt the material. We list the materials that are anticipated to be placed into the Linac Coherent Light Source (LCLS) x-ray free electron laser (XFEL) beam line, their positions, and the absorbed dose, and compare this dose with anticipated damage thresholds.
Hau-Riege, Stefan
Scanning x-ray microscope
A scanning x-ray microscope is described including: an x-ray source capable of emitting a beam of x-rays; a collimator positioned to receive the beam of x-rays and to collimate this beam, a focusing cone means to focus the beam of x-rays, directed by the collimator, onto a focal plane, a specimen mount for supporting a specimen in the focal plane to receive the focused beam of x-rays, and x-ray beam scanning means to relatively move the specimen and the focusing cone means and collimator to scan the focused x-ray beam across the specimen. A detector is disposed adjacent the specimen to detect flourescent photons emitted by the specimen upon exposure to the focused beam of x-rays to provide an electrical output representative of this detection. Means are included for displaying and/or recording the information provided by the output from the detector, as are means for providing information to the recording and/or display means representative of the scan rate and position of the focused x-ray beam relative to the specimen whereby the recording and/or display means can correlate the information received to record and/or display quantitive and distributive information as to the quantity and distribution of elements detected in the specimen. Preferably there is provided an x-ray beam modulation means upstream, relative to the direction of emission of the xray beam, of the focusing cone means.
Wang, C.
X-ray lithography source
A high-intensity, inexpensive X-ray source for X-ray lithography for the production of integrated circuits. Foil stacks are bombarded with a high-energy electron beam of 25 to 250 MeV to produce a flux of soft X-rays of 500 eV to 3 keV. Methods of increasing the total X-ray power and making the cross section of the X-ray beam uniform are described. Methods of obtaining the desired X-ray-beam field size, optimum frequency spectrum and elminating the neutron flux are all described. A method of obtaining a plurality of station operation is also described which makes the process more efficient and economical. The satisfying of these issues makes transition radiation an exellent moderate-priced X-ray source for lithography.
Piestrup, Melvin A. (Woodside, CA); Boyers, David G. (Mountain View, CA); Pincus, Cary (Sunnyvale, CA)
A high-intensity, inexpensive X-ray source for X-ray lithography for the production of integrated circuits is disclosed. Foil stacks are bombarded with a high-energy electron beam of 25 to 250 MeV to produce a flux of soft X-rays of 500 eV to 3 keV. Methods of increasing the total X-ray power and making the cross section of the X-ray beam uniform are described. Methods of obtaining the desired X-ray-beam field size, optimum frequency spectrum and eliminating the neutron flux are all described. A method of obtaining a plurality of station operation is also described which makes the process more efficient and economical. The satisfying of these issues makes transition radiation an excellent moderate-priced X-ray source for lithography. 26 figures.
Piestrup, M.A.; Boyers, D.G.; Pincus, C.
Photonic laser-driven accelerator for GALAXIE
We report on the design and development of an all-dielectric laser-driven accelerator to be used in the GALAXIE (GV-per-meter Acce Lerator And X-ray-source Integrated Experiment) project's compact free-electron laser. The approach of our working design is to construct eigenmodes, borrowing from the field of photonics, which yield the appropriate, highly demanding dynamics in a high-field, short wavelength accelerator. Topics discussed include transverse focusing, power coupling, bunching, and fabrication.
Naranjo, B.; Ho, M.; Hoang, P.; Putterman, S.; Valloni, A.; Rosenzweig, J. B. [UCLA Dept. of Physics and Astronomy Los Angeles, CA 90095-1547 (United States)
SLAC National Accelerator Laboratory - Fifth X-ray Instrument...
and more.) The technique has been used for years to probe materials with visible-light lasers, and more recently with X-ray light from synchrotrons. But the LCLS is the first...
SLAC National Accelerator Laboratory - X-ray Vision Exposes Aerosol...
up exciting possibilities in the study of aerosol dynamics using highly focused X-ray lasers, such as SLAC's Linac Coherent Light Source (LCLS). "Our study shows that LCLS can...
Miniature x-ray source
A miniature x-ray source capable of producing broad spectrum x-ray emission over a wide range of x-ray energies. The miniature x-ray source comprises a compact vacuum tube assembly containing a cathode, an anode, a high voltage feedthru for delivering high voltage to the anode, a getter for maintaining high vacuum, a connection for an initial vacuum pump down and crimp-off, and a high voltage connection for attaching a compact high voltage cable to the high voltage feedthru. At least a portion of the vacuum tube wall is highly x-ray transparent and made, for example, from boron nitride. The compact size and potential for remote operation allows the x-ray source, for example, to be placed adjacent to a material sample undergoing analysis or in proximity to the region to be treated for medical applications.
Trebes, James E. (Livermore, CA); Stone, Gary F. (Livermore, CA); Bell, Perry M. (Tracy, CA); Robinson, Ronald B. (Modesto, CA); Chornenky, Victor I. (Minnetonka, MN)
Synchrotron X-ray Measurements
... fine structure (EXAFS) spectroscopy; (3) variable kinetic energy X-ray ... advanced materials is critical to the development and optimization of products ...
X-ray Absorption Spectroscopy
This review gives a brief description of the theory and application of X-ray absorption spectroscopy, both X-ray absorption near edge structure (XANES) and extended X-ray absorption fine structure (EXAFS), especially, pertaining to photosynthesis. The advantages and limitations of the methods are discussed. Recent advances in extended EXAFS and polarized EXAFS using oriented membranes and single crystals are explained. Developments in theory in understanding the XANES spectra are described. The application of X-ray absorption spectroscopy to the study of the Mn4Ca cluster in Photosystem II is presented.
Yano, Junko; Yachandra, Vittal K.
High-efficiency high-energy Ka source for the critically-required maximum illumination of x-ray optics on Z using Z-petawatt-driven laser-breakout-afterburner accelerated ultrarelativistic electrons LDRD .
Under the auspices of the Science of Extreme Environments LDRD program, a <2 year theoretical- and computational-physics study was performed (LDRD Project 130805) by Guy R Bennett (formally in Center-01600) and Adam B. Sefkow (Center-01600): To investigate novel target designs by which a short-pulse, PW-class beam could create a brighter K{alpha} x-ray source than by simple, direct-laser-irradiation of a flat foil; Direct-Foil-Irradiation (DFI). The computational studies - which are still ongoing at this writing - were performed primarily on the RedStorm supercomputer at Sandia National Laboratories Albuquerque site. The motivation for a higher efficiency K{alpha} emitter was very clear: as the backlighter flux for any x-ray imaging technique on the Z accelerator increases, the signal-to-noise and signal-to-background ratios improve. This ultimately allows the imaging system to reach its full quantitative potential as a diagnostic. Depending on the particular application/experiment this would imply, for example, that the system would have reached its full design spatial resolution and thus the capability to see features that might otherwise be indiscernible with a traditional DFI-like x-ray source. This LDRD began FY09 and ended FY10.
Sefkow, Adam B.; Bennett, Guy R.
Toward TW-Level, Hard X-Ray Pulses at LCLS
Coherent diffraction imaging of complex molecules such as proteins requires a large number (e.g., {approx} 10{sup 13}/pulse) of hard X-ray photons within a time scale of {approx} 10 fs or less. This corresponds to a peak power of {approx} 1 TW, much larger than that currently generated by LCLS or other proposed X-ray free electron lasers (FELs). We study the feasibility of producing such pulses using a LCLS-like, low charge electron beam, as will be possible in the LCLS-II upgrade project, employing a configuration beginning with a SASE amplifier, followed by a 'self-seeding' crystal monochromator, and finishing with a long tapered undulator. Our results suggest that TW-level output power at 8.3 keV is possible from a total undulator system length around 200 m. In addition power levels larger than 100 GW are generated at the third harmonic. We present a tapering strategy that extends the original 'resonant particle' formalism by optimizing the transport lattice to maximize optical guiding and enhance net energy extraction. We discuss the transverse and longitudinal coherence properties of the output radiation pulse and the expected output pulse energy sensitivity, both to taper errors and to power fluctuations on the monochromatized SASE seed.
Fawley, W.M.; Frisch, J.; Huang, Z.; Jiao, Y.; Nuhn, H.-D.; /SLAC; Pellegrini, C.; /SLAC /UCLA; Reiche, S.; /PSI, Villigen; Wu, J,; /SLAC
Optical and x-ray imaging of electron beams using synchrotron emission
In the case of very low eniittance electron and positron storage ring beams, it is impossible to make intrusive measurements of beam properties without increasing the emittance and possibly disrupting the beam. In cases where electron or positron beams have high average power densities (such as free electron laser linacs), intrusive probes such as wires and optical transition radiation screens or Cherenkov emitting screens can be easily damaged or destroyed. The optical and x-ray emissions from the bends in the storage rings and often from linac bending magnets can be used to image the beam profile to obtain emittance information about the beam. The techniques, advantages and limitations of using both optical and x-ray synchrotron emission to measure beam properties are discussed and the possibility of single bunch imaging is considered. The properties of suitable imagers and converters such as phosphors are described. Examples of previous, existing and planned applications are given where available, including a pinhole imaging system currently being designed for the Advanced Photon Source at Argonne National Laboratory.
Wilke, M.D.
Femtosecond Synchronization of Laser Systems for the LCLS
The scientific potential of femtosecond x-ray pulses at linac-driven free-electron lasers such as the Linac Coherent Light Source is tremendous. Time-resolved pump-probe experiments require a measure of the relative arrival time of each x-ray pulse with respect to the experimental pump laser. An optical timing system based on stabilized fiber links has been developed for the LCLS to provide this synchronization. Preliminary results show synchronization of the installed stabilized links at the sub-20-femtosecond level. We present details of the implementation at LCLS and potential for future development.
Byrd, John; /LBL, Berkeley; Doolittle, Lawrence; /LBL, Berkeley; Huang, Gang; /LBL, Berkeley; Staples, John; /LBL, Berkeley; Wilcox, Russell; /LBL, Berkeley; Arthur, John; /SLAC; Frisch, Josef; /SLAC; White, William; /SLAC
Laser Phase Errors in Seeded FELs
Harmonic seeding of free electron lasers has attracted significant attention from the promise of transform-limited pulses in the soft X-ray region. Harmonic multiplication schemes extend seeding to shorter wavelengths, but also amplify the spectral phase errors of the initial seed laser, and may degrade the pulse quality. In this paper we consider the effect of seed laser phase errors in high gain harmonic generation and echo-enabled harmonic generation. We use simulations to confirm analytical results for the case of linearly chirped seed lasers, and extend the results for arbitrary seed laser envelope and phase.
Single-shot Time-resolved X-ray Scattering Measurements in ...
We will describe detailed new measurement system and their results. ... Induced and Observed by Interaction with an Intense Femtosecond X-ray Laser Pulse.
A miniature x-ray source utilizing a hot filament cathode. The source has a millimeter scale size and is capable of producing broad spectrum x-ray emission over a wide range of x-ray energies. The miniature source consists of a compact vacuum tube assembly containing the hot filament cathode, an anode, a high voltage feedthru for delivering high voltage to the cathode, a getter for maintaining high vacuum, a connector for initial vacuum pump down and crimp-off, and a high voltage connection for attaching a compact high voltage cable to the high voltage feedthru. At least a portion of the vacuum tube wall is fabricated from highly x-ray transparent materials, such as sapphire, diamond, or boron nitride.
Trebes, James E. (Livermore, CA); Bell, Perry M. (Tracy, CA); Robinson, Ronald B. (Modesto, CA)
X-ray Imaging Workshop
Imaging and Spectro-microscopy: Imaging and Spectro-microscopy: the Present and the Future Stanford Synchrotron Radiation Laboratory October 8-9, 2002 Organizers: John Miao & Keith Hodgson A workshop on "X-ray Imaging and Spectro-microscopy: the Present and the Future" was held on October 8-9, 2002. This workshop, organized by John Miao (SSRL) and Keith Hodgson (SSRL) provided a forum to discuss the scientific applications of a variety of imaging and spectro-microscopic techniques, including photoemission electron microscopy (PEEM), angle resolved photoemission spectroscopy (ARPES), coherent diffraction imaging, x-ray microscopy, micro-tomography, holographic imaging, and x-ray micro-probe. Twelve invited speakers discussed the important scientific applications of these techniques, and also predicted the future scientific directions with the advance of instrumentation and x-ray sources. The workshop was well attended with over fifty registered attendees.
Dilation x-ray imager a new/faster gated x-ray imager for the NIF
As the yield on implosion shots increases it is expected that the peak x-ray emission reduces to a duration with a FWHM as short as 20 ps for {approx}7 Multiplication-Sign 10{sup 18} neutron yield. However, the temporal resolution of currently used gated x-ray imagers on the NIF is 40-100 ps. We discuss the benefits of the higher temporal resolution for the NIF and present performance measurements for dilation x-ray imager, which utilizes pulse-dilation technology [T. J. Hilsabeck et al., Rev. Sci. Instrum. 81, 10E317 (2010)] to achieve x-ray imaging with temporal gate times below 10 ps. The measurements were conducted using the COMET laser, which is part of the Jupiter Laser Facility at the Lawrence Livermore National Laboratory.
Nagel, S. R.; Bell, P. M.; Bradley, D. K.; Ayers, M. J.; Barrios, M. A.; Felker, B.; Smith, R. F.; Collins, G. W.; Jones, O. S.; Piston, K.; Raman, K. S. [Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550 (United States); Hilsabeck, T. J.; Kilkenny, J. D.; Chung, T.; Sammuli, B. [General Atomics, P.O. Box 85608, San Diego, California 92186-5608 (United States); Hares, J. D.; Dymoke-Bradshaw, A. K. L. [Kentech Instruments Ltd., Wallingford, Oxfordshire OX10 (United Kingdom)
Tokamak x ray diagnostic instrumentation
Three classes of x-ray diagnostic instruments enable measurement of a variety of tokamak physics parameters from different features of the x-ray emission spectrum. (1) The soft x-ray (1 to 50 keV) pulse-height-analysis (PHA) diagnostic measures impurity concentrations from characteristic line intensities and the continuum enhancement, and measures the electron temperature from the continuum slope. (2) The Bragg x-ray crystal spectrometer (XCS) measures the ion temperature and neutral-beam-induced toroidal rotation velocity from the Doppler broadening and wavelength shift, respectively, of spectral lines of medium-Z impurity ions. Impurity charge state distributions, precise wavelengths, and inner-shell excitation and recombination rates can also be studied. X rays are diffracted and focused by a bent crystal onto a position-sensitive detector. The spectral resolving power E/..delta..E is greater than 10/sup 4/ and time resolution is 10 ms. (3) The x-ray imaging system (XIS) measures the spatial structure of rapid fluctuations (0.1 to 100 kHZ) providing information on MHD phenomena, impurity transport rates, toroidal rotation velocity, plasma position, and the electron temperature profile. It uses an array of silicon surface-barrier diodes which view different chords of the plasma through a common slot aperture and operate in current (as opposed to counting) mode. The effectiveness of shields to protect detectors from fusion-neutron radiation effects has been studied both theoretically and experimentally.
Hill, K.W.; Beiersdorfer, P.; Bitter, M.; Fredrickson, E.; Von Goeler, S.; Hsuan, H.; Johnson, L.C.; Liew, S.L.; McGuire, K.; Pare, V.
Laser Assisted Emittance Exchange
We describe here the laser assisted emittance exchange (LAEE) technique. A laser operating in the transverse mode (TEM10 or TEM01) is used to interact with the electron beam in a dispersive region and to initiate the transverse-to-longitudinal emittance exchange. It is shown that with the LAEE one can generate an electron beam with ultralow transverse emittance, which allows one to significantly bring down the size of an X-ray free electron laser (FEL) and greatly extend the availability of these light sources. The technique can also be used to enhance the performances of X-ray FELs in storage rings. The timing and energy jitter problems for the standard emittance exchange and LAEE techniques are also discussed.
Xiang, Dao; /SLAC
X-ray Transition Energies Search Form
[skip navigation] X-ray Transition Energies Database Main Page Search for X-ray transition energies by element(s), transition ...
2002 Free Electron Laser Conference and Workshop
submitted Paper Preparation Instructions Social Events Concert and Prix Fixe Dinner Banquet Vendor Exhibits List of Exhibitors Exhibitor Information Booth Layout and Assignments...
Metal Photocathodes for Free Electron Laser Applications
and then an appropriate TTL trigger pulse is generated.Detector TDC Start (NIM) Preamp (TTL) PP MIRA Figure 3.21: Aand then an appropriate TTL trigger pulse is generated.
Greaves, Corin Michael Ricardo
Axial interaction free-electron laser
Electron orbits from a helical axial wiggler in an axial guide field are absolutely unstable as power is extracted from the particles. For off-axis beams an axial FEL mechanism exists when the axial electric field in a TM mode is wiggled to interact with the axial velocity of the electrons that form the beam. The interaction strength is comparable to that for helical FELs and is insensitive to beam orbit errors. The orbits for this mechanism are extremely stable in the absence of space charge and lead to high extraction efficiencies without particle phasing incoherence or interception. This interaction mechanism is suitable for use with intense annular electron beams for high power generation at microwave frequencies.
SciTech Connect: "free electron lasers"
Renewable Energy Laboratory (NREL), Golden, CO (United States) Naval Petroleum and Oil Shale Reserves (United States) Navarro Nevada Environmental Services Nevada Field Office,...
Conference: Entanglement, Holography, and the Quantum Phases of Matter Citation Details In-Document Search Title: Entanglement, Holography, and the Quantum Phases of Matter...
Plasmon-enhanced photocathode for high brightness and high repetition rate x-ray sources
High brightness electron sources are at the heart of anew generation of x-ray sources based on the Free ElectronLaser (FEL) as well as in Energy Recovery Linac (ERL) and Inverse Compton Scattering (ICS) sources.The source of electrons consists of a photoinjector, comprised of a laser-driven photocathode in a high gradient electric field produced by an rf cavity. The function of the rf cavity is to provide a field sufficient for acceleration of electrons to relativistic velocity over a small distance, thus minimizing effects of the space-charge. Even so, the dense electron beam required for high brightness suffers from a space charge field that chirps and reshapes the electron pulse increasing beam emittance and thus reducing the overall brightness. This emittance growth can be avoided if the initial distribution of electrons is pancake shaped, with a semicircular transverse intensity profile. In this case, the electron distribution develops under its space charge field from a pancake into a uniformly filled ellipsoidal beam. This condition, referred to as the blowout regime, requires ultrashort pulses less than 100 fs long and has been successfully demonstrated recently in a high gradient photoinjector.
Polyakov, Aleksandr; Senft, Christoph; Thompson, K. F.; Feng, J.; Cabrini, S.; Schuck, P. J.; Padmore, Howard; Peppernick, Samuel J.; Hess, Wayne P.
Compact x-ray source and panel
A compact, self-contained x-ray source, and a compact x-ray source panel having a plurality of such x-ray sources arranged in a preferably broad-area pixelized array. Each x-ray source includes an electron source for producing an electron beam, an x-ray conversion target, and a multilayer insulator separating the electron source and the x-ray conversion target from each other. The multi-layer insulator preferably has a cylindrical configuration with a plurality of alternating insulator and conductor layers surrounding an acceleration channel leading from the electron source to the x-ray conversion target. A power source is connected to each x-ray source of the array to produce an accelerating gradient between the electron source and x-ray conversion target in any one or more of the x-ray sources independent of other x-ray sources in the array, so as to accelerate an electron beam towards the x-ray conversion target. The multilayer insulator enables relatively short separation distances between the electron source and the x-ray conversion target so that a thin panel is possible for compactness. This is due to the ability of the plurality of alternating insulator and conductor layers of the multilayer insulators to resist surface flashover when sufficiently high acceleration energies necessary for x-ray generation are supplied by the power source to the x-ray sources.
Sampayon, Stephen E. (Manteca, CA)
Theoretical treatments of the bound-free contribution and experimental best practice in X-ray Thomson scattering from warm dense matter
By comparison with high-resolution synchrotron x-ray experimental results, we assess several theoretical treatments for the bound-free (core-electron) contribution to x-ray Thomson scattering (i.e., also known as nonresonant inelastic x-ray scattering). We identify an often overlooked source of systematic error in the plane-wave form factor approximation (PWFFA) used in the inference of temperature, ionization state, and free electron density in some laser-driven compression studies of warm dense matter. This error is due to a direct violation of energy conservation in the PWFFA. We propose an improved practice for the bound-free term that will be particularly relevant for XRTS experiments performed with somewhat improved energy resolution at the National Ignition Facility or the Linac Coherent Light Source. Our results raise important questions about the accuracy of state variable determination in XRTS studies, given that the limited information content in low-resolution XRTS spectra does not strongly constrain the models of electronic structure being used to fit the spectra.
Mattern, Brian A.; Seidler, Gerald T. [Department of Physics, University of Washington, Seattle, Washington 98195-1560 (United States)
Using Light to Control How X Rays Interact with Matter
Using Light to Control How X Using Light to Control How X Rays Interact with Matter Using Light to Control How X Rays Interact with Matter Print Wednesday, 27 January 2010 00:00 Schemes that use one light pulse to manipulate interactions of another with matter are well developed in the visible-light regime where an optical control pulse influences how an optical probe pulse interacts with a medium. This approach has opened new research directions in fields like quantum computing and nonlinear optics, while also spawning entirely new research areas, such as electromagnetically induced transparency and slow light. However, it has been unclear whether similar optical control schemes could be used to modify how x rays interact with matter. In a dramatic breakthrough demonstration at the ALS, a Berkeley Lab-Argonne National Laboratory group has now used powerful visible-light lasers to render a nominally opaque material transparent to x rays. While x-ray transparency will have immediate applications at x-ray light sources, the important result is that the findings lay a foundation for a broader spectrum of applications.
Using Light to Control How X Rays Interact with Matter Print Using Light to Control How X Rays Interact with Matter Print Schemes that use one light pulse to manipulate interactions of another with matter are well developed in the visible-light regime where an optical control pulse influences how an optical probe pulse interacts with a medium. This approach has opened new research directions in fields like quantum computing and nonlinear optics, while also spawning entirely new research areas, such as electromagnetically induced transparency and slow light. However, it has been unclear whether similar optical control schemes could be used to modify how x rays interact with matter. In a dramatic breakthrough demonstration at the ALS, a Berkeley Lab-Argonne National Laboratory group has now used powerful visible-light lasers to render a nominally opaque material transparent to x rays. While x-ray transparency will have immediate applications at x-ray light sources, the important result is that the findings lay a foundation for a broader spectrum of applications.
Imaging X-ray Thomson Scattering Spectrometer Design and Demonstration
In many laboratory astrophysics experiments, intense laser irradiation creates novel material conditions with large, one-dimensional gradients in the temperature, density, and ionization state. X-ray Thomson scattering is a powerful technique for measuring these plasma parameters. However, the scattered signal has previously been measured with little or no spatial resolution, which limits the ability to diagnose inhomogeneous plasmas. We report on the development of a new imaging x-ray Thomson spectrometer (IXTS) for the Omega laser facility. The diffraction of x-rays from a toroidally-curved crystal creates high-resolution images that are spatially resolved along a one-dimensional profile while spectrally dispersing the radiation. This focusing geometry allows for high brightness while localizing noise sources and improving the linearity of the dispersion. Preliminary results are presented from a scattering experiment that used the IXTS to measure the temperature profile of a shocked carbon foam.
Gamboa, E.J. [University of Michigan; Huntington, C.M. [University of Michigan; Trantham, M.R. [University of Michigan; Keiter, P.A [University of Michigan; Drake, R.P. [University of Michigan; Montgomery, David [Los Alamos National Laboratory; Benage, John F. [Los Alamos National Laboratory; Letzring, Samuel A. [Los Alamos National Laboratory
Beam Dynamics Study of X-Band Linac Driven X-Ray FELS
Several linac driven X-ray Free Electron Lasers (XFELs) are being developed to provide high brightness photon beams with very short, tunable wavelengths. In this paper, three XFEL configurations are proposed that achieve LCLS-like performance using X-band linac drivers. These linacs are more versatile, efficient and compact than ones using S-band or C-band rf technology. For each of the designs, the overall accelerator layout and the shaping of the bunch longitudinal phase space are described briefly. During the last 40 years, the photon wavelengths from linac driven FELs have been pushed shorter by increasing the electron beam energy and adopting shorter period undulators. Recently, the wavelengths have reached the X-ray range, with FLASH (Free-Electron Laser in Hamburg) and LCLS (Linac Coherent Light Source) successfully providing users with soft and hard X-rays, respectively. FLASH uses a 1.2 GeV L-band (1.3 GHz) superconducting linac driver and can deliver 10-70 fs FWHM long photon pulses in a wavelength range of 44 nm to 4.1 nm. LCLS uses the last third of the SLAC 3 km S-band (2.856 GHz) normal-conducting linac to produce 3.5 GeV to 15 GeV bunches to generate soft and hard X-rays with good spatial coherence at wavelengths from 2.2 nm to 0.12 nm. Newer XFELs (at Spring8 and PSI) use C-band (5.7 GHz) normal-conducting linac drivers, which can sustain higher acceleration gradients, and hence shorten the linac length, and are more efficient at converting rf energy to bunch energy. The X-band (11.4 GHz) rf technology developed for NLC/GLC offers even higher gradients and efficiencies, and the shorter rf wavelength allows more versatility in longitudinal bunch phase space compression and manipulation. In the following sections, three different configurations of X-band linac driven XFELs are described that operate from 6 to 14 GeV. The first (LOW CHARGE DESIGN) has an electron bunch charge of only 10 pC; the second (OPTICS LINEARIZATION DESIGN) is based on optics linearization of the longitudinal phase space in the first stage bunch compressor and can operate with either a high (250 pC) or low (20 pC) bunch charge; and the third (LCLS INJECTOR DESIGN) is similar to LCLS but uses an X-band linac after the first stage bunch compressor at 250 MeV to achieve a final beam energy up to 14 GeV. Compared with LCLS, these X-band linacs are at least a factor of three shorter.
Adolphsen, C.; Limborg-Deprey, C.; Raubenheimer, T.O.; Wu, J.; /SLAC; Sun, Y.; /SLAC
Coherent X-ray Imaging Data Bank (CXIDB): An Open Repository for CXI Experimental Data
Nowadays there are several groups around the world doing excellent work using different kinds of techniques all based on the physics of coherent X-ray imaging (CXI). Due to several reasons, including lack of a standard file format, there has been limited sharing of data which severely limits possible synergies inside the community. At the same time there is a population of researchers who do not have access to the facilities required to make such kinds of experiments, or do not have the expertise and resources necessary to carry them out. But many of them would be able to test new ideas and techniques if they would have access to the experimental data. The main goal of the Coherent X-ray Imaging Data Bank is to address these problems by creating an open repository for CXI experimental data. Such a repository provides several important benefits including: Expansion of the CXI community directly leading to an increase in the science output, the existence of an archival place for all the experimental data would ensure that such data does not gets lost forever when the group that did the experiment is no longer interested in the data, the availability of the experimental data to the entire community greatly facilitates reproducibility, leading to higher quality and more transparent science, the development of a well documented file format for CXI data facilitates data sharing and might one day lead to its emergence as a de facto standard. Current free electron laser facilities such as the LCLS are capable of producing very large amounts of data (20TB a day) and the coming European FEL is expected to increase this rate a factor of 500. The analyzes of such large bodies of data will have to be distributed through a large community to make it manageable, and this repository could be an important facilitator in this process.
Heteroepitaxy of Nd{sub 0.67}Sr{sub 0.33}MnO{sub 3} on silicon for bolometric x-ray detector application
We have recently reported the design concept and sensor fabrication for a novel bolometric x-ray detector based on a rare earth manganite material for application as a total energy monitor for the Linac Coherent Light Source (LCLS) free electron laser at the Stanford Linear Accelerator Center (SLAC). The detector employs epitaxial thin films of Nd{sub 0.67}Sr{sub 0.33}MnO{sub 3} grown on Si by pulsed laser deposition. In this paper we report details of the fabrication of the actual detector, its response characteristics under photon illumination from LCLS, and improvements in the growth scheme of the sensor material on Si using a buffer/template layer scheme that employs yttria-stabilized zirconia, cerium oxide (CeO{sub 2}), and bismuth titanate (Bi{sub 4}Ti{sub 3}O{sub 12}). The thermal sensor response changes linearly with the energy of an optical calibration laser as expected, and the signals from optical and x-ray pulses at LCLS are very similar, thereby validating the design concept. To the best of our knowledge, the LCLS detector application reported here is the first practical use of colossal magnetoresistive manganite bolometers.
Yong, G. J.; Kolagani, Rajeswari M.; Adhikari, S. [Department of Physics, Astronomy and Geosciences, Towson University, Towson, Maryland 21252 (United States); Drury, O. B.; Gardner, C.; Bionta, R. M.; Friedrich, S. [Lawrence Livermore National Laboratory, 7000 East Ave., Livermore, California 94550 (United States)
Microgap x-ray detector
An x-ray detector which provides for the conversion of x-ray photons into photoelectrons and subsequent amplification of these photoelectrons through the generation of electron avalanches in a thin gas-filled region subject to a high electric potential. The detector comprises a cathode (photocathode) and an anode separated by the thin, gas-filled region. The cathode may comprise a substrate, such a beryllium, coated with a layer of high atomic number material, such as gold, while the anode can be a single conducting plane of material, such as gold, or a plane of resistive material, such as chromium/silicon monoxide, or multiple areas of conductive or resistive material, mounted on a substrate composed of glass, plastic or ceramic. The charge collected from each electron avalanche by the anode is passed through processing electronics to a point of use, such as an oscilloscope.
Wuest, Craig R. (Danville, CA); Bionta, Richard M. (Livermore, CA); Ables, Elden (Livermore, CA)
Highly efficient pulsed power supply system with a two-stage LC generator and a step-up transformer for fast capillary discharge soft x-ray laser at shorter wavelength
Highly efficient and compact pulsed power supply system for a capillary discharge soft x-ray laser (SXRL) has been developed. The system consists of a 2.2 {mu}F two-stage LC inversion generator, a 2:54 step-up transformer, a 3 nF water capacitor, and a discharge section with a few tens of centimeter length capillary. Adoption of the pulsed transformer in combination with the LC inversion generator enables us to use only one gap switch in the circuit for charging the water capacitor up to about 0.5 MV. Furthermore, step-up ratio of a water capacitor voltage to a LC inversion generator initial charging voltage is about 40 with energy transfer efficiency of about 50%. It also leads to good reproducibility of a capillary discharge which is necessary for lasing a SXRL stably. For the study of the possibility of lasing a SXRL at shorter wavelength in a small laboratory scale, high-density and high-temperature plasma column suitable for the laser can be generated relatively easily with this system.
Sakai, Yusuke; Takahashi, Shnsuke; Komatsu, Takanori; Song, Inho; Watanabe, Masato; Hotta, Eiki [Department of Energy Sciences, Tokyo Institute of Technology, 4259-J2-35, Nagatsuta, Midori-ku, Yokohama 226-8502 (Japan)
Flat Field Anomalies in an X-ray CCD Camera Measured Using a Manson X-ray Source
The Static X-ray Imager (SXI) is a diagnostic used at the National Ignition Facility (NIF) to measure the position of the X-rays produced by lasers hitting a gold foil target. The intensity distribution taken by the SXI camera during a NIF shot is used to determine how accurately NIF can aim laser beams. This is critical to proper NIF operation. Imagers are located at the top and the bottom of the NIF target chamber. The CCD chip is an X-ray sensitive silicon sensor, with a large format array (2k x 2k), 24 ?m square pixels, and 15 ?m thick. A multi-anode Manson X-ray source, operating up to 10kV and 10W, was used to characterize and calibrate the imagers. The output beam is heavily filtered to narrow the spectral beam width, giving a typical resolution E/?E?10. The X-ray beam intensity was measured using an absolute photodiode that has accuracy better than 1% up to the Si K edge and better than 5% at higher energies. The X-ray beam provides full CCD illumination and is flat, within �1% maximum to minimum. The spectral efficiency was measured at 10 energy bands ranging from 930 eV to 8470 eV. We observed an energy dependent pixel sensitivity variation that showed continuous change over a large portion of the CCD. The maximum sensitivity variation occurred at 8470 eV. The geometric pattern did not change at lower energies, but the maximum contrast decreased and was not observable below 4 keV. We were also able to observe debris, damage, and surface defects on the CCD chip. The Manson source is a powerful tool for characterizing the imaging errors of an X-ray CCD imager. These errors are quite different from those found in a visible CCD imager.
M. J. Haugh and M. B. Schneider
X-Ray Diffraction on NIF
The National Ignition Facility (NIF) is currently a 192 beam, 1.6 MJ laser. NIF Ramp-Compression Experiments have already made the relevant exo-planet pressure range from 1 to 50 Mbar accessible. We Proposed to Study Carbon Phases by X-Ray Diffraction on NIF. Just a few years ago, ultra-high pressure phase diagrams for materials were very 'simple'. New experiments and theories point out surprising and decidedly complex behavior at the highest pressures considered. High pressures phases of aluminum are also predicted to be complex. Recent metadynamics survey of carbon proposed a dynamic pathway among multiple phases. We need to develop diagnostics and techniques to explore this new regime of highly compressed matter science. X-Ray Diffraction - Understand the phase diagram/EOS/strength/texture of materials to 10's of Mbar. Strategy and physics goals: (1) Powder diffraction; (2) Begin with diamond; (3) Continue with metals etc.; (4) Explore phase diagrams; (5) Develop liquid diffraction; and (6) Reduce background/improve resolution.
Eggert, J H; Wark, J
Development of extreme ultraviolet and soft x-ray multilayer optics for scientific studies with femtosecond/attosecond sources
132] J. Arthur. Status of the LCLS x-ray FEL program. Reviewelectron lasers(such as LCLS at Stanford[132]) are expected
Aquila, Andrew Lee
Chest x-Rays | Department of Energy
Chest x-Rays Chest x-Rays Chest x-Rays Chest X-ray B-Reading The B-reading is a special reading of a standard chest x-ray film performed by a physician certified by the National Institute for Occupational Safety and Health (NIOSH). The reading looks for changes on the chest x-ray that may indicate exposure and disease caused by agents such as asbestos or silica. The B-reading is considered a special reading because doctors who are certified by NIOSH to perform B-readings use a specific protocol to read and record the findings as developed by the International Labour Organization (ILO). The ILO's protocol provides rules for systematically examining the x-ray in a step-by-step method and recording certain abnormalities or changes on the chest x-ray that can be attributable to
Spectral analysis of X-ray binaries
In this thesis, I present work from three separate research projects associated with observations of X-ray binaries. Two of those revolve around spectral characteristics of neutron star low-mass X-ray binaries (NS-LMXBs), ...
Fridriksson, Joel Karl
Cryotomography x-ray microscopy state
An x-ray microscope stage enables alignment of a sample about a rotation axis to enable three dimensional tomographic imaging of the sample using an x-ray microscope. A heat exchanger assembly provides cooled gas to a sample during x-ray microscopic imaging.
Le Gros, Mark (Berkeley, CA); Larabell, Carolyn A. (Berkeley, CA)
High-energy x-ray backlighter spectrum measurements using calibrated image plates
The x-ray spectrum between 18 and 88 keV generated by a petawatt laser driven x-ray backlighter target was measured using a 12-channel differential filter pair spectrometer. The spectrometer consists of a series of filter pairs on a Ta mask coupled with an x-ray sensitive image plate. A calibration of Fuji{trademark} MS and SR image plates was conducted using a tungsten anode x-ray source and the resulting calibration applied to the design of the Ross pair spectrometer. Additionally, the fade rate and resolution of the image plate system were measured for quantitative radiographic applications. The conversion efficiency of laser energy into silver K{alpha} x rays from a petawatt laser target was measured using the differential filter pair spectrometer and compared to measurements using a single photon counting charge coupled device.
Maddox, B.R.; Park, H.S.; Remington, B.A.; Izumi, N.; Chen, S.; Chen, C.; Kimminau, G.; Ali, Z.; Haugh, M.J.; Ma, Q. (LLNL); (NWU); (Oxford); (NSTec)
The x-ray spectrum between 18 and 88 keV generated by a petawatt laser driven x-ray backlighter target was measured using a 12-channel differential filter pair spectrometer. The spectrometer consists of a series of filter pairs on a Ta mask coupled with an x-ray sensitive image plate. A calibration of Fuji MS and SR image plates was conducted using a tungsten anode x-ray source and the resulting calibration applied to the design of the Ross pair spectrometer. Additionally, the fade rate and resolution of the image plate system were measured for quantitative radiographic applications. The conversion efficiency of laser energy into silver K{alpha} x rays from a petawatt laser target was measured using the differential filter pair spectrometer and compared to measurements using a single photon counting charge coupled device.
Maddox, B. R.; Park, H. S.; Remington, B. A.; Izumi, N.; Chen, S.; Chen, C. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Kimminau, G. [Department of Physics, Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU (United Kingdom); Ali, Z.; Haugh, M. J. [National Security Technologies, LLC, Livermore, California 94550 (United States); Ma, Q. [DND-CAT, Argonne National Laboratory, Argonne, Illinois 60439-4857 (United States)
An experimental apparatus for diffraction-limites soft x-ray nanofocusing
Realizing the experimental potential of high-brightness, next generation synchrotron and free-electron laser light sources requires the development of reflecting x-ray optics capable of wavefront preservation and high-resolution nano-focusing. At the Advanced Light Source (ALS) beamline 5.3.1, we are developing broadly applicable, high-accuracy, in situ, at-wavelength wavefront measurement techniques to surpass 100-nrad slope measurement accuracy for diffraction-limited Kirkpatrick-Baez (KB) mirrors. The at-wavelength methodology we are developing relies on a series of wavefront-sensing tests with increasing accuracy and sensitivity, including scanning-slit Hartmann tests, grating-based lateral shearing interferometry, and quantitative knife-edge testing. We describe the original experimental techniques and alignment methodology that have enabled us to optimally set a bendable KB mirror to achieve a focused, FWHM spot size of 150 nm, with 1 nm (1.24 keV) photons at 3.7 mrad numerical aperture. The predictions of wavefront measurement are confirmed by the knife-edge testing.The side-profiled elliptically bent mirror used in these one-dimensional focusing experiments was originally designed for a much different glancing angle and conjugate distances. This work demonstrates that high-accuracy, at-wavelength wavefront-slope feedback can be used to optimize the pitch, roll, and mirror-bending forces in situ, using procedures that are deterministic and repeatable.
Merthe, Daniel; Goldberg, Kenneth; Yashchuk, Valeriy; Yuan, Sheng; McKinney, Wayne; Celestre, Richard; Mochi, Iacopo; Macdougall, James; Morrison, Gregory; Rakawa, Senajith; Anderson, Erik; Smith, Brian; Domning, Edward; Warwick, Tony; Padmore, Howard
Tokamak physics studies using x-ray diagnostic methods
X-ray diagnostic measurements have been used in a number of experiments to improve our understanding of important tokamak physics issues. The impurity content in TFTR plasmas, its sources and control have been clarified through soft x-ray pulse-height analysis (PHA) measurements. The dependence of intrinsic impurity concentrations and Z/sub eff/ on electron density, plasma current, limiter material and conditioning, and neutral-beam power have shown that the limiter is an important source of metal impurities. Neoclassical-like impurity peaking following hydrogen pellet injection into Alcator C and a strong effect of impurities on sawtooth behavior were demonstrated by x-ray imaging (XIS) measurements. Rapid inward motion of impurities and continuation of m = 1 activity following an internal disruption were demonstrated with XIS measurements on PLT using injected aluminum to enhance the signals. Ion temperatures up to 12 keV and a toroidal plasma rotation velocity up to 6 x 10/sup 5/ m/s have been measured by an x-ray crystal spectrometer (XCS) with up to 13 MW of 85-keV neutral-beam injection in TFTR. Precise wavelengths and relative intensities of x-ray lines in several helium-like ions and neon-like ions of silver have been measured in TFTR and PLT by the XCS. The data help to identify the important excitation processes predicted in atomic physics. Wavelengths of n = 3 to 2 silver lines of interest for x-ray lasers were measured, and precise instrument calibration techniques were developed. Electron thermal conductivity and sawtooth dynamics have been studied through XIS measurements on TFTR of heat-pulse propagation and compound sawteeth. A non-Maxwellian electron distribution function has been measured, and evidence of the Parail-Pogutse instability identified by hard x-ray PHA measurements on PLT during lower-hybrid current-drive experiments.
Hill, K.W.; Bitter, M.; von Goeler, S.; Beiersdorfer, P.; Fredrickson, E.; Hsuan, H.; McGuire, K.; Sauthoff, N.R.; Sesnic, S.; Stevens, J.E.
K-alpha conversion efficiency measurments for x-ray scattering in inertial confinement fusion plasmas
The conversion efficiency of ultra short-pulse laser radiation to K-{alpha} x-rays has been measured for various chlorine-containing targets to be used as x-ray scattering probes of dense plasmas. The spectral and temporal properties of these sources will allow spectrally-resolved x-ray scattering probing with picosecond temporal resolution required for measuring the plasma conditions in inertial confinement fusion experiments. Simulations of x-ray scattering spectra from these plasmas show that fuel capsule density, capsule ablator density, and shock timing information may be inferred.
Kritcher, A L; Neumayer, P; Urry, M K; Robey, H; Niemann, C; Landen, O L; Morse, E; Glenzer, S H
X-ray transmissive debris shield
An X-ray debris shield for use in X-ray lithography that is comprised of an X-ray window having a layer of low density foam exhibits increased longevity without a substantial increase in exposure time. The low density foam layer serves to absorb the debris emitted from the X-ray source and attenuate the shock to the window so as to reduce the chance of breakage. Because the foam is low density, the X-rays are hardly attenuated by the foam and thus the exposure time is not substantially increased.
Spielman, R.B.
Spielman, Rick B. (Albuquerque, NM)
Lessening X-ray damage is healthy for protein discovery data too | Argonne
The brightness and energy of X-ray beams are critical properties for The brightness and energy of X-ray beams are critical properties for research. The APS Upgrade will make our X-ray beams brighter, meaning more X-rays can be focused onto a smaller, laser-like spot, allowing researchers to gather more data in greater detail in less time. Lessening X-ray damage is healthy for protein discovery data too December 16, 2013 Tweet EmailPrint New recommendations for using X-rays promise to speed investigations aimed at understanding the structure and function of biologically important proteins - information critical to the development of new drugs. Scientists from two U.S. Department of Energy national laboratories, Argonne and Brookhaven, and the University of Washington, Seattle, evaluated options to remedy problems affecting data collection in their new
Efficient multi?keV x?ray sources from Ti?doped aerogel targets
We have measured the production of hv ? 4.7 keV x?rays from low?density Ti?doped aerogel (? ? 3 mg/cc) targets at the OMEGA laser facility (University of Rochester)
K. B. Fournier; C. Constantin; G. Gregori; M. C. Miller; C. A. Back; L. J. Suter; J. Davis; J. Grun
Scientific Needs for Future X-ray Sources in the U.S. -- A White Paper
scientific user program at LCLS, the first x-ray laser, toERL SPring-8 Ring ELETTRA LCLS II & III Ring Upgrade SDL SRFERMI FEL ALS Ring Ring FEL LCLS SPARC Upgrade SSRF FEL PAL-
Falcone, Roger
X-ray data booklet. Revision
A compilation of data is presented. Included are properties of the elements, electron binding energies, characteristic x-ray energies, fluorescence yields for K and L shells, Auger energies, energy levels for hydrogen-, helium-, and neonlike ions, scattering factors and mass absorption coefficients, and transmission bands of selected filters. Also included are selected reprints on scattering processes, x-ray sources, optics, x-ray detectors, and synchrotron radiation facilities. (WRF)
Vaughan, D. (ed.)
A composite window structure is described for transmitting x-ray radiation and for shielding radiation generated debris. In particular, separate layers of different x-ray transmissive materials are laminated together to form a high strength, x-ray transmissive debris shield which is particularly suited for use in high energy fluences. In one embodiment, the composite window comprises alternating layers of beryllium and a thermoset polymer.
NIST X-Ray Transition Energies
... with the International System of measurement ... titled "X-ray transition energies: new approach ... and by NIST's Systems Integration for Manufacturing ...
X-ray Line Profile Analysis
... Magnetic Composite Materials � X-Ray Studies of Structural Effects Induced by Pulsed (30 Tesla), High Magnetic Fields at the Advanced Photon Source�...
NIST: X-Ray Mass Attenuation Coefficients
... NIST reserves the right to charge for these data in the ... ?/? and the mass energy-absorption coefficient ... The tables cover energies of the photon (x-ray ...
Hard X-Ray Quad Collimator
Technology Development and Commercialization Division One of the best ways to obtain small?size x?ray beams for structural biology research is to ...
A Low-Charge, Hard X-Ray FEL Driven with an X-band Injector and Accelerator
After the successful operation of FLASH (Free-Electron Laser in Hamburg) and LCLS (Linac Coherent Light Source), soft and hard X-ray Free Electron Lasers (FELs) are being built, designed or proposed at many accelerator laboratories. Acceleration employing lower frequency RF cavities, ranging from L-band to C-band, is usually adopted in these designs. In the first stage bunch compression, higher-frequency harmonic RF system is employed to linearize the beam's longitudinal phase space, which is nonlinearly chirped during the lower frequency RF acceleration process. In this paper, a hard X-ray FEL design using an all X-band accelerator at 11.424 GHz (from photo-cathode RF gun to linac end) is presented, without the assistance of any harmonic RF linearization. It achieves LCLS-like performance at low charge using X-band linac drivers, which is more versatile, efficient and compact than ones using S-band or C-band rf technology. It employs initially 42 microns long (RMS), low charge (10 pC) electron bunches from an X-band photoinjector. An overall bunch compression ratio of roughly 100 times is proposed in a two stage bunch compressor system. The start-to-end macro-particle 3-D simulation employing several computer codes is presented in this paper, where space charge, wakefields, incoherent and coherent synchrotron radiation (ISR and CSR) effects are included. Employing an undulator with a short period of 1.5 cm, a Genesis FEL simulation shows successful lasing at a wavelength of 0.15 nm with a pulse length of 2 fs and a power saturation length as short as 20 meters, which is equivalent to LCLS low charge mode. Its overall length of both accelerators and undulators is 180 meters (much shorter than the effective LCLS overall length of 1230 meters, including an accelerator length of 1100 meters and an undulator length of 130 meters), which makes it possible to be built in places where only limited space is available.
X-Ray Multilayer Database from the LBL Center for X-Ray Optics (CXRO)
An important activity of the Center for X-ray Optics (CXRO) is research on x-ray mirrors and their use in optical devices to focus and deflect x-ray beams. The two kinds of mirrors most widely used are glancing incidence reflectors and multilayer coatings. The X-Ray Multilayer Database is based on the results of surveys taken at the biennial Physics of X-Ray Multilayer Structures conferences. It contains measured x-ray reflectances reported for various multilayers. The database is provided as a service to the x-ray and multilayer research communities and is intended to reflect the state-of-the-art in multilayer x-ray mirrors. (Specialized Interface)
X-ray spectroscopy of neutron star low-mass X-ray binaries
In this thesis, I present work spanning a variety of topics relating to neutron star lowmass X-ray binaries (LMXBs) and utilize spectral information from X-ray observations to further our understanding of these sources. ...
Krauss, Miriam Ilana
Materials Analysis by Soft x-ray Scanning Transmission X-ray ...
DOE-Funded Research Projects Win 39 R&D Awards for 2010 | Department...
X-ray free electron laser energy monitor non-intrusively measures the energy of ultrahigh intensity X-ray pulses produced by revolutionary X-ray free electron lasers. Grating...
X-ray Diffraction Crystal Calibration and Characterization
National Security Technologies� X-ray Laboratory is comprised of a multi-anode Manson type source and a Henke type source that incorporates a dual goniometer and XYZ translation stage. The first goniometer is used to isolate a particular spectral band. The Manson operates up to 10 kV and the Henke up to 20 kV. The Henke rotation stages and translation stages are automated. Procedures have been developed to characterize and calibrate various NIF diagnostics and their components. The diagnostics include X-ray cameras, gated imagers, streak cameras, and other X-ray imaging systems. Components that have been analyzed include filters, filter arrays, grazing incidence mirrors, and various crystals, both flat and curved. Recent efforts on the Henke system are aimed at characterizing and calibrating imaging crystals and curved crystals used as the major component of an X-ray spectrometer. The presentation will concentrate on these results. The work has been done at energies ranging from 3 keV to 16 keV. The major goal was to evaluate the performance quality of the crystal for its intended application. For the imaging crystals we measured the laser beam reflection offset from the X-ray beam and the reflectivity curves. For the curved spectrometer crystal, which was a natural crystal, resolving power was critical. It was first necessary to find sources of crystals that had sufficiently narrow reflectivity curves. It was then necessary to determine which crystals retained their resolving power after being thinned and glued to a curved substrate.
Michael J. Haugh; Richard Stewart; Nathan Kugland
Generation of Coherent X-Ray Radiation through Modulation Compression
In this paper, we propose a scheme to generate tunable coherent X-ray radiation for future light source applications. This scheme uses an energy chirped electron beam, a laser modulator, a laser chirper and two bunch compressors to generate a prebunched kilo-Ampere current electron beam from a few tens Ampere electron beam out of a linac. The initial modulation energy wavelength can be compressed by a factor of 1 + h{sub b}R{sub 56}{sup a} in phase space, where h{sub b} is the energy bunch length chirp introduced by the laser chirper, R{sub 56}{sup a} is the momentum compaction factor of the first bunch compressor. As an illustration, we present an example to generate more than 400 MW, 170 attoseconds pulse, 1 nm coherent X-ray radiation using a 60 A electron beam out of the linac and 200 nm laser seed. Both the final wavelength and the radiation pulse length in the proposed scheme are tunable by adjusting the compression factor and the laser parameters.
Qiang, Ji; /LBL, Berkeley; Wu, Juhao; /SLAC
X-Ray Preheating of Window Materials in Direct-Drive Shock-Wave Timing Experiments
The optical properties of x-ray preheated planar-window materials relevant for shock-wave timing experiments were studied on the OMEGA Laser System. The behavior of diamond windows exposed to x rays is consistent with a simple model based on the generation of free charge carriers. Polystyrene windows showed indications of optical transitions due to molecular states that are created by the ionizing radiation.
Theobald, W.; Miller, J. E.; Boehly, T.R.; Vianello, E, Meyerhofer, D.D.; Sangster, T.C.; Eggert, J.; Celliers, P.M.
High-Resolution X-ray Spectroscopy
... In support of these efforts, we also maintain laboratory x-ray sources from 1 keV to 300 keV, energy and intensity calibration facilities, and a vacuum ...
X-ray grid-detector apparatus
A hybrid grid-detector apparatus for x-ray systems wherein a microchannel plate structure has an air-interspaced grid portion and a phosphor/optical fluid-filled grid portion. The grids are defined by multiple adjacent channels separated by lead-glass septa. X-rays entering the air-interspaced grid portion at an angle of impingement upon the septa are attenuated, while non-impinging x-rays pass through to the phosphor/fluid filled portion. X-ray energy is converted to luminescent energy in the phosphor/fluid filled portion and the resultant beams of light are directed out of the phosphor/optical fluid filled portion to an imaging device.
Boone, John M. (Folsom, CA); Lane, Stephen M. (Oakland, CA)
X-Ray Nanoimaging: Instruments and Methods
X-Ray Nanoimaging: Instruments and Methods To be held as part of SPIE. http:spie.orgOP318 August 28-29, 2013; San Diego, California, USA...
X-ray image intensifier phosphor
Y/sub 1-x/Gd/sub x/.PO$sub 4$:Tb$sup 3+$ is an effective phosphor for use in X-ray intensifier screens and in nuclear radiation detection systems.
D' Silva, A.P.; Fassel, V.A.
Kaonic Atom X?ray Spectra
In kaonic atoms energy displacement and broadening of states result from the strong interaction. The most simple kaonic atoms like kaonic hydrogen and deuterium open the possibility to measure this strong interaction induced shift and width by x?ray spectroscopy. In the SIDDHARTA experiment al LNF (Frascati) the DA?NE electron?positron collider delivers nearly mono?energetic negatively charged kaons from ? meson decay. This unique kaon source is used to form kaonic atoms. New high performance x?ray detectors (silicon drift detectors) arranged in an array allow x?ray spectroscopy with high energy resolution combined with timing capability. High precision x?ray measurements like SIDDHARTA at LNF will open the way to study the low energy regime of the strong force in the antikaon?nucleon interaction. The experiment and its current status is presented in this talk.
J. Marton; on behalf of the SIDDHARTA Collaboration
APS Bending Magnet X-rays and
Irradiation of Nd-Fe-B Permanent Magnets with Irradiation of Nd-Fe-B Permanent Magnets with APS Bending Magnet X-rays and 60 Co γ-rays J. Alderman and P.K. Job APS Operations Division Advanced Photon Source J. Puhl Ionizing Radiation Division National Institute of Standards and Technology June 2000 Table of Contents Introduction Radiation-Induced Demagnetization of Permanent Magnets Resources Required γ-ray Irradiation Results and Analysis of γ-ray Irradiation X-ray Irradiation Results and Analysis of X-ray Irradiation Summary and Conclusions Acknowledgements References Tables and Figures Introduction The Advanced Photon Source (APS), as well as other third-generation synchrotron light sources, uses permanent magnets in the insertion devices to produce x-rays for scientific
X-Ray Scattering Group, Condensed Matter Physics & Materials...
- Brookhaven National Laboratory, Upton, NY Beamline X1A2 - Soft x-ray diffraction and nano-imaging Beamline X17 - X-ray powder diffraction Beamline X22C - Resonant x-ray...
X-Ray Emission from Compact Sources
This paper presents a review of the physical parameters of neutron stars and black holes that have been derived from X-ray observations. I then explain how these physical parameters can be used to learn about the extreme conditions occurring in regions of strong gravity, and present some recent evidence for relativistic effects seen in these systems. A glossary of commonly used terms and a short tutorial on the names of X-ray sources are also included.
Cominsky, L
Argonne CNM: X-Ray Microscopy Capabilities
X-Ray Microscopy Facilities X-Ray Microscopy Facilities The Hard X-Ray Nanoprobe (HXN) facility provides scanning fluorescence, scanning diffraction, and full-field transmission and tomographic imaging capabilities with a spatial resolution of 30 nm over a spectral range of 6-12 keV. Modes of Operation Full-Field Transmission Imaging and Nanotomography X-ray transmission imaging uses both the absorption and phase shift of the X-ray beam by the sample as contrast mechanisms. Absorption contrast is used to map the sample density. Elemental constituents can be located by using differential edge contrast in this mode. Phase contrast can be highly sensitive to edges and interfaces even when the X-ray absorption is weak. These contrast mechanisms are exploited to image samples rapidly in full-field transmission mode under various environmental conditions, or combined with nanotomography methods to study the three-dimensional structure of complex and amorphous nanomaterials with the HXN.
Inelastic X-ray and Nuclear Resonant Scattering
Beamlines Divisions Argonne Home > Advanced Photon Source > Inelastic X-ray and Nuclear Resonant Scattering The Inelastic X-ray and Nuclear Resonant Scattering group...
Sandia National Laboratories X-ray Tube with Magnetic Electron ...
... for the U.S. Department of Energy�s National ... high average power large area X-ray tube provides increased X-ray generation efficiency through ...
Copper Ridges Nearly Double X-ray Sensor Performance
... Physics Letters,* can measure X-ray energies with an ... X-rays and measure the energy based on ... by NASA and the NIST Office of Microelectronics ...
THz Pump and X-Ray Probe Development at LCLS
We report on measurements of broadband, intense, coherent transition radiation at terahertz frequencies, generated as the highly compressed electron bunches in Linear Coherent Light Source (LCLS) pass through a thin metal foil. The foil is inserted at 45{sup o} to the electron beam, 31 m downstream of the undulator. The THz emission passes downward through a diamond window to an optical table below the beamline. A fully compressed 350-pC bunch produces up to 0.5 mJ in a nearly half-cycle pulse of 50 fs FWHM with a spectrum peaking at 10 THz. We estimate a peak field at the focus of over 2.5 GV/m. A 20-fs Ti:sapphire laser oscillator has recently been installed for electro-optic measurements. We are developing plans to add an x-ray probe to this THz pump, by diffracting FEL x rays onto the table with a thin silicon crystal. The x rays would arrive with an adjustable time delay after the THz. This will provide a rapid start to user studies of materials excited by intense single-cycle pulses and will serve as a step toward a THz transport line for LCLS-II.
Fisher, Alan S; /SLAC, LCLS; Durr, Hermann; /SIMES, Stanford /SLAC, PULSE; Lindenberg, Aaron; Stanford U., Materials Sci.Dept.; /SIMES, Stanford /SLAC, PULSE; Reis, David; /SIMES, Stanford /SLAC, PULSE /Stanford U., Dept. Appl. Phys.; Frisch, Josef; Loos, Henrik; Petree, Mark; /SLAC, LCLS; Daranciang, Dan; /Stanford U., Chem. Dept.; Fuchs, Matthias; /SLAC, PULSE; Ghimire, Shambhu; /SLAC, PULSE; Goodfellow, John; /Stanford U., Materials Sci. Dept.
Radiographic X-Ray Pulse Jitter
The Dual Beam Radiographic Facility consists of two identical radiographic sources. Major components of the machines are: Marx generator, water-filled pulse-forming line (PFL), water-filled coaxial transmission line, three-cell inductive voltage adder, and rod-pinch diode. The diode pulse has the following electrical specifications: 2.25-MV, 60-kA, 60-ns. Each source has the following x-ray parameters: 1-mm-diameter spot size, 4-rad at 1 m, 50-ns full width half max. The x-ray pulse is measured with PIN diode detectors. The sources were developed to produce high resolution images on single-shot, high-value experiments. For this application it is desirable to maintain a high level of reproducibility in source output. X-ray pulse jitter is a key metric for analysis of reproducibility. We will give measurements of x-ray jitter for each machine. It is expected that x-ray pulse jitter is predominantly due to PFL switch jitter, and therefore a correlation of the two will be discussed.
Mitton, C. V., Good, D. E., Henderson, D. J., Hogge, K. W.
Time-domain sampling of x-ray pulses using an ultrafast sample response
We employ the ultrafast response of a 15.4 nm thin SrRuO{sub 3} layer grown epitaxially on a SrTiO{sub 3} substrate to perform time-domain sampling of an x-ray pulse emitted from a synchrotron storage ring. Excitation of the sample with an ultrashort laser pulse triggers coherent expansion and compression waves in the thin layer, which turn the diffraction efficiency on and off at a fixed Bragg angle during 5 ps. This is significantly shorter than the duration of the synchrotron x-ray pulse of 100 ps. Cross-correlation measurements of the ultrafast sample response and the synchrotron x-ray pulse allow to reconstruct the x-ray pulse shape.
Gaal, P.; Shayduk, R. [Helmholtz-Zentrum Berlin fuer Materialien und Energie GmbH, Wilhelm-Conrad-Roentgen Campus, BESSY II, Albert-Einstein-Str. 15, 12489 Berlin (Germany); Schick, D.; Herzog, M.; Bojahr, A.; Goldshteyn, J.; Navirian, H. A.; Leitenberger, W. [Institut fuer Physik und Astronomie, Universitaet Potsdam, Karl-Liebknecht-Str. 24-25, 14476 Potsdam (Germany); Vrejoiu, I. [Max-Planck-Institut fuer Mikrostrukturphysik, Weinberg 2, 06120 Halle (Germany); Khakhulin, D.; Wulff, M. [European Synchrotron Radiation Facility (ESRF), 6 rue Jules Horowitz, 38000 Grenoble (France); Bargheer, M. [Helmholtz-Zentrum Berlin fuer Materialien und Energie GmbH, Wilhelm-Conrad-Roentgen Campus, BESSY II, Albert-Einstein-Str. 15, 12489 Berlin (Germany); Institut fuer Physik und Astronomie, Universitaet Potsdam, Karl-Liebknecht-Str. 24-25, 14476 Potsdam (Germany)
X-Ray Data from the X-Ray Data Booklet Online
The original X-Ray Data Booklet, published in 1985, became a classic reference source. The online version has been significantly revised and updated to reflect today's science. Hundreds of pages of authoritative data provide the x-ray properties of elements, information on synchrotron radiation, scattering processes, optics and detectors, and other related calculations, formulas, and data tables.
Thompson, Albert C.; Attwood, David T.; Gullikson, Eric M.; Howells, Malcolm R.; Kortright, Jeffrey B.; Robinson, Arthur L.; Underwood, James H.; Kim, Kwang-Je; Kirz, Janos; Lindau, Ingolf; Pianetta, Piero; Winick, Herman; Williams, Gwyn P.; Scofield, James H.
Absolute, soft x-ray calorimetry on the Z facility at Sandia National Laboratories
Simple and reliable x-ray fluence measurements, in addition to time-resolved diagnostics, are needed to understand the physics of hot Z-pinch plasmas. A commercially available laser calorimeter has been modified for measuring soft x-ray fluence from the Z facility at Sandia National Laboratories. The x-ray absorber of this calorimeter is an aluminum disk, attached to a two-dimensional thermopile and surrounded by an isoperibol shroud. The time-integral and the maximum of the thermopile voltage signal are both proportional to the x-ray energy deposited. Data are collected for 90 seconds, and the instrument has, thus far, been used in the 1--25 mJ range. A wider dynamic measuring range for x-ray fluence (energy/area) can be achieved by varying the area of the defining aperture. The calorimeter is calibrated by an electrical substitution method. Calibrations are performed before and after each x-ray experiment on the Z facility. The calibration of the time-integral of the thermopile voltage vs. energy deposited (or the peak of thermopile voltage vs. energy deposited) is linear with zero offset at the 95% confidence level. The irreproducibility of the calibration is <2%, and the imprecision in the measurement of the incident x-ray energy (inferred from signal noise and the calibration) is estimated to be {approximately}0.9 mJ (95% confidence level). The inaccuracy is estimated at {+-}10%, due to correctable systematic errors (e.g., baseline shifts). Comparisons have been made of the calorimeter to time-resolved x-ray diagnostics, e.g., bolometers and XRD (x-ray diode) arrays, by integrating the flux measured by these instruments over time.
Fehl, D.L.; Muron, D.J.; Leeper, R.J.; Chandler, G.A.; Deeney, C.; Spielman, R.B.
X-ray Science Division: Groups
Division: Groups Division: Groups Atomic, Molecular and Optical Physics (AMO) Primary Contact: Stephen Southworth Work focuses on understanding how strong optical and x-ray fields interact with matter, with an emphasis on photonic control of electronic, atomic and molecular motion. Chemical and Materials Science (CMS) Primary Contact: Randy Winans Research Disciplines: Chemistry, Materials Science Detectors (DET) Primary Contact: Antonino Miceli GMCA Structural Biology Facility (MX) Primary Contact: Robert Fischetti Research Disciplines: Biology, Life Sciences Imaging (IMG) Primary Contact: Francesco DeCarlo Research Disciplines: Materials Science, Biology, Physics, Life Sciences Inelastic X-ray & Nuclear Resonant Scattering (IXN) Primary Contact: Thomas Gog Research Disciplines: Condensed Matter Physics, Geophysics, Materials
Radiobiological studies using gamma and x rays.
There are approximately 500 self-shielded research irradiators used in various facilities throughout the U.S. These facilities use radioactive sources containing either 137Cs or 60Co for a variety of biological investigations. A report from the National Academy of Sciences[1] described the issues with security of particular radiation sources and the desire for their replacement. The participants in this effort prepared two peer-reviewed publications to document the results of radiobiological studies performed using photons from 320-kV x rays and 137Cs on cell cultures and mice. The effectiveness of X rays was shown to vary with cell type.
Potter, Charles Augustus; Longley, Susan W.; Scott, Bobby R. [Lovelace Respiratory Research Institute, Albuquerque, NM; Lin, Yong [Lovelace Respiratory Research Institute, Albuquerque, NM; Wilder, Julie [Lovelace Respiratory Research Institute, Albuquerque, NM; Hutt, Julie A. [Lovelace Respiratory Research Institute, Albuquerque, NM; Padilla, Mabel T. [Lovelace Respiratory Research Institute, Albuquerque, NM; Gott, Katherine M. [Lovelace Respiratory Research Institute, Albuquerque, NM
Evaluation of the sensitivity and fading characteristics of an image plate system for x-ray diagnostics
Image plates (IPs) are a reusable recording media capable of detecting ionizing radiation, used to diagnose x-ray emission from laser-plasma experiments. Due to their superior performance characteristics in x-ray applications [C. C. Bradford, W. W. Peppler, and J. T. Dobbins III, Med. Phys. 26, 27 (1999) and J. Digit. Imaging. 12, 54 (1999)], the Fuji Biological Analysis System (BAS) IPs are fielded on x-ray diagnostics for the HELEN laser by the Plasma Physics Department at AWE. The sensitivities of the Fuji BAS IPs have been absolutely calibrated for absolute measurements of x-ray intensity in the energy range of 0-100 keV. In addition, the Fuji BAS IP fading as a function of time was investigated. We report on the characterization of three Fuji BAS IP responses to x-rays using a radioactive source, and discrete x-ray line energies generated by the Excalibur soft x-ray facility and the Defense Radiological Standards Centre filter-fluorescer hard x-ray system at AWE.
Meadowcroft, A. L.; Bentley, C. D.; Stott, E. N. [Plasma Physics Department, AWE Aldermaston, Reading, Berkshire RG7 4PR (United Kingdom)
The Soft-X-Ray Spectral Shape of X-Ray-Weak Seyferts
(I) We observed eight Seyfert~2s and two X--ray--weak Seyfert~1/QSOs with the ROSAT PSPC, and one Seyfert~2 with the ROSAT HRI. These targets were selected from the Extended 12\\um\\ Galaxy Sample. (II) Both Seyfert~1/QSOs vary by factors of 1.5---2. The photon indices steepen in the more luminous state, consistent with the variability being mainly due to the softest X--rays, which are confined to a size of less than a parsec. (III) Both the Seyfert~2s and Seyfert~1/QSOs are best fit with a photon index of $\\Gamma\\sim3$, which is steeper than the canonical value of $\\Gamma\\sim1.7$ measured for X--ray--strong Seyferts by ROSAT and at higher energies. Several physical explanations are suggested for the steeper slopes of X--ray--weak objects. (IV) We observed one Seyfert~2, NGC~5005, with the ROSAT HRI, finding about 13\\% of the soft X--rays to come from an extended component. This and other observations suggest that different components to the soft X--ray spectrum of some, if not all, X--ray--weak Seyferts may come from spatially distinct regions.
Brian Rush; Matthew A. Malkan
Sharper Focusing of Hard X-rays
Sharper Focusing of Hard X-rays FROM: Physics News Update Number 773 #1, April 12, 2006, by Phil Schewe and Ben Stein Note: This text has been slightly modified from the original. Sharper focusing of hard x-rays has been achieved with a device developed at Argonne National Lab. Because of their high energy, x-rays are hard to focus: they can be reflected from a surface but only at a glancing angle (less than a tenth of a degree); they can be refracted but the index of refraction is very close to 1, so that making efficient lenses becomes a problem; and they can be diffracted, but the relatively thick, variable pitch grating required for focusing is tricky to achieve. The Argonne device is of the diffraction type, and it consists of a stack of alternating layers of metal and silicon, made by depositing progressively thicker layers. When the x-rays fall on such a structure, nearly edge-on, what they see is a grating (called a linear zone plate) consisting of a sort of bar-code pattern.
Massively parallel X-ray scattering simulations
Although present X-ray scattering techniques can provide tremendous information on the nano-structural properties of materials that are valuable in the design and fabrication of energy-relevant nano-devices, a primary challenge remains in the analyses ...
Abhinav Sarje; Xiaoye S. Li; Slim Chourou; Elaine R. Chan; Alexander Hexemer
Multiple wavelength x-ray monochromators
An apparatus and method is provided for separating input x-ray radiation containing first and second x-ray wavelengths into spatially separate first and second output radiation which contain the first and second x-ray wavelengths, respectively. The apparatus includes a crystalline diffractor which includes a first set of parallel crystal planes, where each of the planes is spaced a predetermined second distance from one another. The crystalline diffractor also includes a second set of parallel crystal planes inclined at an angle with respect to the first set of crystal planes where each of the planes of the second set of parallel crystal planes is spaced a predetermined second distance from one another. In one embodiment, the crystalline diffractor is comprised of a single crystal. In a second embodiment, the crystalline diffractor is comprised of a stack of two crystals. In a third embodiment, the crystalline diffractor includes a single crystal that is bent for focussing the separate first and second output x-ray radiation wavelengths into separate focal points.
Steinmeyer, P.A.
X-Ray and Neutron Diffraction
Oct 20, 2010 ... Advanced X-Ray Scattering Techniques for Multi-Length Scale ... ?-Ti using the 3DXRD station 34-ID-E at the Advanced Photon Source, Argonne National Laboratory. ... Research at APS 34-ID-E, partly funded by BES/DOE.
Small Angle X-Ray Scattering Detector
A detector for time-resolved small-angle x-ray scattering includes a nearly constant diameter, evacuated linear tube having an end plate detector with a first fluorescent screen and concentric rings of first fiber optic bundles for low angle scattering detection and an annular detector having a second fluorescent screen and second fiber optic bundles concentrically disposed about the tube for higher angle scattering detection. With the scattering source, i.e., the specimen under investigation, located outside of the evacuated tube on the tube's longitudinal axis, scattered x-rays are detected by the fiber optic bundles, to each of which is coupled a respective photodetector, to provide a measurement resolution, i.e., dq/q, where q is the momentum transferred from an incident x-ray to an x-ray scattering specimen, of 2% over two (2) orders of magnitude in reciprocal space, i.e., qmax/qmin approx=lO0.
Hessler, Jan P.
SciTech Connect: "smart grid"
Compact X-ray Free Electron Laser from a Laser-plasma Accelerator using a Transverse Gradient Undulator Citation Details In-Document Search Title: Compact X-ray Free Electron Laser...
X-Ray Interactions with Matter
The primary interactions of low-energy x-rays within condensed matter, viz. photoabsorption and coherent scattering, are described for photon energies outside the absorption threshold regions by using atomic scattering factors. The atomic scattering factors may be accurately determined from the atomic photoabsorption cross sections using modified Kramers-Kronig dispersion relations. From a synthesis of the currently available experimental data and recent theoretical calculations for photoabsorption, the angle-independent, forward-scattering components of the atomic scattering factors have been thus semiempirically determined and tabulated here for 92 elements and for the region 50-30,000 eV. Atomic scattering factors for all angles of coherent scattering and at the higher photon energies are obtained from these tabulated forward-scattering values by adding a simple angle-dependent form-factor correction. The incoherent scattering contributions that become significant for the light elements at the higher photon energies are similarly determined. The basic x-ray interaction relations that are used in applied x-ray physics are presented here in terms of the atomic scattering factors. The bulk optical constants are also related to the atomic scattering factors. These atomic and optical relations are applied to the detailed calculation of the reflectivity characteristics of a series of practical x-ray mirror, multilayer, and crystal monochromators. Comparisons of the results of this semiempirical,"atom-like", description of x-ray interactions for the low-energy region with those of experiment and ab initio theory are presented. (Taken from the abstract in OSTI Record 6131765) (Specialized Interface)
Henke, B.L.; Gullikson, E.M.; Davis, J.C.
Lasers without Mirrors, Designed by Supercomputer - NERSC SCience News
Lasers without Lasers without Mirrors, Designed by Supercomputer Lasers without Mirrors, Designed by Supercomputer October 14, 2009 | Tags: Lasers, Life Sciences, Materials Science Contact: Ji Qiang | Lawrence Berkeley National Laboratory | email@example.com John Corlett | Lawrence Berkeley National Laboratory, Center for Beam Physics | firstname.lastname@example.com Sometimes it takes a big machine to understand the tiniest details. That's the case with free electron lasers (FELs). The powerful X-rays they generate can probe matter directly at the level of atomic interactions and chemical-bond formation, letting scientists observe such phenomena as chemical reactions in trace elements, electric charges in photosynthesis and the structure of microscopic machines. FELs have the potential to
Wolter-like high resolution x-ray imaging microscope for Rayleigh Taylor instabilities studies
In the context of the inertial confinement fusion, experiments have been carried out on the Phebus laser facility to study the Rayleigh-Taylor instabilities (RTIs) at the ablation front. Premodulated brominated plastic targets (25 {mu}m thick) with a modulation wavelength between 12 and 50 {mu}m were accelerated with a temporally shaped soft x-ray pulse emitted from a hohlraum with a maximum radiation temperature of about 115 eV. The RTI growth was measured by face-on radiography using a microscope coupled with an x-ray streak camera, which has spatial and temporal resolutions of about 5 {mu}m and 50 ps, respectively. The acceleration was derived from side-on velocity measurements. The microscope we have developed is a Wolter-like microscope which consists of two toroiedal mirrors. We will present the experimental and theoretical potentialities of this microscope: characterization with an x-ray generator and plasma laser x-ray source (Phebus facility) for two-dimensional (2D) and 1D time-resolved imaging studies. Spatial resolution of about 4 {mu}m was achieved in the 1-5 keV range. The Wolter-like constitutes an interesting device for laser plasma diagnostics and will be very useful in the Laser Megajoules experiments conducted with more powerful lasers.
Troussel, Ph.; Meyer, B.; Reverdin, R.; Angelier, B.; Lidove, G.; Salvatore, P.; Richard, A. [Commissariat a l'Energie Atomique, DAM-Ile de France, BP 12, 91680 Bruyeres-les-Chatel (France); Commissariat a l'Energie Atomique, Saclay 91191 (France); Commissariat a l'Energie Atomique, CESTA, BP2, 33114 Le Barp (France)
X-ray preheating of window materials in direct-drive shock-wave timing experiments
The optical properties of x-ray preheated planar-window materials relevant for shock-wave timing experiments were studied on the OMEGA Laser System. The x-ray radiation was generated by 100 ps, 1x10{sup 15} W/cm{sup 2} laser pulses incident on planar plastic targets, instantaneously affecting samples located {approx}0.7 mm away. An abrupt onset of strong absorption of an optical probe beam ({lambda}=532 nm) and a temporally varying refractive index were measured in polystyrene and diamond windows. The behavior of diamond windows exposed to x rays is consistent with a simple model based on the generation of free charge carriers. Polystyrene windows showed indications of optical transitions due to molecular states that are created by the ionizing radiation.
Theobald, W.; Miller, J. E.; Boehly, T. R.; Vianello, E.; Meyerhofer, D. D.; Sangster, T. C.; Eggert, J.; Celliers, P. M. [Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623-1299 (United States); Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)
Rise time measurement for ultrafast X-ray pulses
A pump-probe scheme measures the rise time of ultrafast x-ray pulses. Conventional high speed x-ray diagnostics (x-ray streak cameras, PIN diodes, diamond PCD devices) do not provide sufficient time resolution to resolve rise times of x-ray pulses on the order of 50 fs or less as they are being produced by modern fast x-ray sources. Here, we are describing a pump-probe technique that can be employed to measure events where detector resolution is insufficient to resolve the event. The scheme utilizes a diamond plate as an x-ray transducer and a p-polarized probe beam.
Celliers, Peter M. (Berkeley, CA); Weber, Franz A. (Oakland, CA); Moon, Stephen J. (Tracy, CA)
Rise Time Measurement for Ultrafast X-Ray Pulses
Celliers, Peter M.; Weber, Franz A.; Moon, Stephen J.
X-ray Thomson scattering measurements from shock-compressed deuterium
X-ray Thomson scattering has recently been shown to be an effective method of diagnosing a variety of high energy density plasma conditions. We apply this powerful technique to the widely studied problem of shock-compressed liquid deuterium. The behavior of deuterium under extreme conditions has received considerable attention due to its central role in models of giant planets and the importance of the high-pressure insulator-metal transition. We have used spectrally resolved x-ray scattering from electron-plasma waves to perform microscopic observations of ionization during compression. In these experiments, a single shock was launched in cryogenic deuterium reaching compressions of 3x. The 2 keV Ly-{alpha} line in silicon was used as an x-ray source in a forward scattering geometry. In addition to elastic scattering from tightly bound electrons, this low probe energy accessed the collective plasmon oscillations of delocalized electrons. Inelastic scattering from the plasmons allowed accurate measurements of the free electron density through the spectral position of the resonance and provided an estimate of the temperature through its ratio with the elastic feature. Combined with velocity interferometry from the reflective shock front, this lead to a direct determination of the ionization state. We compare the measured ionization conditions with computational models. Additionally, we discuss the possibility of using this technique to determine electrical conductivity and to directly observe pressure-induced molecular dissociation along the Hugoniot.
Davis, P.; Doeppner, T.; Rygg, J. R.; Fortmann, C.; Unites, W.; Salmonson, J.; Collins, G. W.; Landen, O. L.; Falcone, R. W.; Glenzer, S. H. [University of California, Berkeley. Berkeley, CA, 94720 (United States); Lawrence Livermore National Laboratory. Livermore, CA 94551 (United States); University of California, Berkeley. Berkeley, CA, 94720 (United States)
X-ray flashes and X-ray rich gamma ray bursts. Memorie della Societa� Astronomica Italiana
Abstract. X-ray flashes are detected in the Wide Field Cameras on BeppoSAX in the energy range 2-25 keV as bright X-ray sources lasting of the order of minutes, but remaining undetected in the Gamma Ray Bursts Monitor on BeppoSAX. They have properties very similar to the x-ray counterparts of GRBs and account for some of the Fast X-ray Transient events seen in almost every x-ray satellite. We review their X-ray properties and show that x-ray flashes are in fact very soft, x-ray rich, untriggered gamma ray bursts, in which the peak energy in 2-10 keV x-rays could be up to a factor of 100 larger than the peak energy in the 50-300 keV gamma ray range. The frequency is ? 100 yr ?1. 1 Fast X-ray Transients/High-latitude X-ray Transients Fast X-ray Transients have been observed with many x-ray satellites. In particular they are seen with x-ray instruments that scan the entire sky on a regular basis. Such events are detected in one sky scan and disappeared in the next, typically limiting the duration to be longer than a minute and shorter than a few hours. For this reason they are called Fast Transients. The first transients
John Heise; Jean In �t Z; Peter M. Woods
X-rays Illuminate Ancient Archimedes Text
Related Links: Related Links: May 2005 Headlines TIP Article Press Release Walters Art Museum SSRL Home Page SLAC Home Page Stanford Home Page Tuesday, 31 May 2005 X-rays Illuminate Ancient Archimedes Text (contact: Uwe Bergmann, firstname.lastname@example.com) Archimedes Figure Image provided by Will Noel, The Walters Art Museum An early transcription of Archimedes' mathematical theories has been brought to light through the probing of high-intensity x-rays at SSRL's BL6-2. The text contains part of the Method of Mechanical Theorems, one of Archimedes' most important works, which was probably copied out by a scribe in the tenth century. The parchment on which it was written was later scraped down and reused as pages in a twelfth century prayer book, producing a document known as a palimpsest (which comes from the Greek,
High resolution x-ray microscope
The authors present x-ray images of grid meshes and biological material obtained using a microspot x-ray tube with a multilayer optic and a 92-element parabolic compound refractive lens (CRL) made of a plastic containing only hydrogen and carbon. Images obtained using this apparatus are compared with those using an area source with a spherical lens and a spherical lens with multilayer condenser. The authors found the best image quality using the multilayer condenser with a parabolic lens, compared to images with a spherical lens and without the multilayer optics. The resolution was measured using a 155-element parabolic CRL and a multilayer condenser with the microspot tube. The experiment demonstrates about 1.1 {mu}m resolution.
Gary, C. K.; Park, H.; Lombardo, L. W.; Piestrup, M. A.; Cremer, J. T.; Pantell, R. H.; Dudchik, Y. I. [Adelphi Technology, Inc. 981-B Industrial Road, San Carlos, California 94070 (United States); Department of Electrical Engineering, Stanford University, Stanford, California 94305 (United States); Institute of Applied Physics Problems, Kurchatova 7, Minsk 220064 (Belarus)
BRILLIANCE X-RAY SCATTERING FOR BRILLIANCE X-RAY SCATTERING FOR LIFE SCIENCES (LIX) Group Leader: Lin Yang Proposal Team: O. Bilsel 1 , B. Hsiao 2 , H. Huang 3 , T. Irving 4 , A. Menzel 5 , L. Pollack 6 , C. Riekel 7 , J. Rubert 8 , H. Tsuruta 9 , L. Yang 10 1 University of Massachusetts, 2 Stony Brook University, 3 Rice University, 4 IIT, 5SLS, 6 Cornell University, 7 European Synchrotron Radiation Facility, 8 NEU, 9 Stanford Synchrotron Radiation Lightsource, 10 Brookhaven National Laboratory TECHNIQUES AND CAPABILITIES APPLICATIONS ADDITIONAL INFORMATION * Energy range 2-20keV using undulator source. Simultaneous SAXS/WAXS to cover 0.003-3Å -1 at 12keV with 1 micron spot size * Time-resolved solution scattering with resolution of (1) microseconds to milliseconds using continuous-flow mixing (5µm x 10µm spot size) and (2) milliseconds using stopped-
Sample holder for x-ray diffractometry
A sample holder for use with x-ray diffractometers with the capability to rotate the sample, as well as to adjust the position of the sample in the x, y, and z directions. Adjustment in the x direction is accomplished through loosening set screws, moving a platform, and retightening the set screws. Motion translators are used for adjustment in the y and z directions. An electric motor rotates the sample, and receives power from the diffractometer.
Hesch, V.L.
Thin-film thickness measurement using x-ray peak ratioing in the scanning electron microscope
The procedure used to measure laser target film thickness using a scanning electron microscope is summarized. This method is generally applicable to any coating on any substrate as long as the electron energy is sufficient to penetrate the coating and the substrate produces an x-ray signal which can pass back through the coating and be detected. (MOW)
Elliott, N.E.; Anderson, W.E.; Archuleta, T.A.; Stupin, D.M.
TENDER ENERGY X-RAY ABSORPTION TENDER ENERGY X-RAY ABSORPTION SPECTROSCOPY (TES) Project Team: S. Bare 1,2 , J. Brandes 3 , T. Buonassisi 4 , J. Chen 5,2 , M. Croft 6 , E. DiMasi 7 , A. Frenkel 8,2 , D. Hesterberg 9 , S. Hulbert 7,2 , S. Khalid 7 , S. Myneni 10 , P. Northrup 7,11 , E.T. Rasbury 11 , B. Ravel 12 , R. Reeder 11 , J. Rodriguez 7,2 , D. Sparks 5,13 , V. Stojanoff 7 , G. Waychunas 14 1 UOP LLC, 2 Synchrotron Catalysis Consortium, 3 Skidaway Inst. of Oceanography, 4 MIT Laboratory for Photovoltaics Research, 5 Univ. of Delaware, 6 Rutgers Univ., 7 Brookhaven National Lab, 8 Yeshiva Univ., 9 North Carolina State Univ., 10 Princeton Univ., 11 Stony Brook Univ., 12 NIST, 13 Delaware Environmental Inst., 14 Lawrence Berkeley National Lab TECHNIQUES: High performance and in-situ X-ray absorption spectroscopy and spatially-resolved XAS of
Hard X-ray Variability of AGN
Aims: Active Galactic Nuclei are known to be variable throughout the electromagnetic spectrum. An energy domain poorly studied in this respect is the hard X-ray range above 20 keV. Methods: The first 9 months of the Swift/BAT all-sky survey are used to study the 14 - 195 keV variability of the 44 brightest AGN. The sources have been selected due to their detection significance of >10 sigma. We tested the variability using a maximum likelihood estimator and by analysing the structure function. Results: Probing different time scales, it appears that the absorbed AGN are more variable than the unabsorbed ones. The same applies for the comparison of Seyfert 2 and Seyfert 1 objects. As expected the blazars show stronger variability. 15% of the non-blazar AGN show variability of >20% compared to the average flux on time scales of 20 days, and 30% show at least 10% flux variation. All the non-blazar AGN which show strong variability are low-luminosity objects with L(14-195 keV) < 1E44 erg/sec. Conclusions: Concerning the variability pattern, there is a tendency of unabsorbed or type 1 galaxies being less variable than the absorbed or type 2 objects at hardest X-rays. A more solid anti-correlation is found between variability and luminosity, which has been previously observed in soft X-rays, in the UV, and in the optical domain.
V. Beckmann; S. D. Barthelmy; T. J. -L. Courvoisier; N. Gehrels; S. Soldi; J. Tueller; G. Wendt
Biological Imaging by Soft X-Ray Diffraction Microscopy
Biological Imaging by Soft X-Ray Diffraction Microscopy Print Electron and x-ray microscopes are a valuable tool for both the life and materials sciences, but they are limited in...
SLAC National Accelerator Laboratory - SLAC X-rays Help Discover...
which pulses 120 times a second. In the instant before the intense X-rays destroy a nanocrystal, detectors record a flash of X-ray diffraction information. Finally, scientists use...
Using Light to Control How X Rays Interact with Matter Using Light to Control How X Rays Interact with Matter Print Wednesday, 27 January 2010 00:00 Schemes that use one light...
Microstructural Mapping Using High-Energy X-Ray Scattering
Abstract Scope, Advanced characterization methods at the APS permit unique in- situ ... The combination of an undulator source, brilliance preserving optics and focusing .... Ultra-Small-Angle X-Ray Scattering�X-Ray Photon Correlation�...
Energy Determination of X-Ray Transition Energies Using the ...
... We chose to measure x-ray transition energies from NIST ... This resulted in the production of x-ray emission ... would yield not only an energy scale for ...
Strengthened lithium for x-ray blast windows
Lithium's high x-ray transparency makes it an attractive material for windows intended to protect soft x-ray diagnostics in high energy density experiments. Pure lithium is soft and weak, but lithium mixed with lithium hydride powder becomes harder and stronger, in principle without any additional x-ray absorption. A comparison with the standard material for x-ray windows, beryllium, suggests that lithium or lithium strengthened by lithium hydride may well be an excellent option for such windows.
Pereira, N. R. [Ecopulse Inc., P.O. Box 528, Springfield, Virginia 22150 (United States); Imam, M. A. [Materials Science and Technology Division, Naval Research Laboratory, Washington, DC 20375 (United States)
Electron and X-Ray Microscopy: Structural Characterization of ...
Oct 28, 2009 ... Recent Advances in Structural Characterization of Materials: Electron and X-Ray Microscopy: Structural Characterization of Nanoscale�...
Ultra Fast X-ray Streak Camera for TIM Based Platforms
Ultra fast x-ray streak cameras are a staple for time resolved x-ray measurements. There is a need for a ten inch manipulator (TIM) based streak camera that can be fielded in a newer large scale laser facility. The LLNL ultra fast streak camera's drive electronics have been upgraded and redesigned to fit inside a TIM tube. The camera also has a new user interface that allows for remote control and data acquisition. The system has been outfitted with a new sensor package that gives the user more operational awareness and control.
Marley, E; Shepherd, R; Fulkerson, E S; James, L; Emig, J; Norman, D
Ultra fast x-ray streak camera for ten inch manipulator based platforms
Ultra fast x-ray streak cameras are a staple for time resolved x-ray measurements. There is a need for a ten inch manipulator (TIM) based streak camera that can be fielded in a newer large scale laser facility. The Lawrence Livermore National Laboratory ultra fast streak camera's drive electronics have been upgraded and redesigned to fit inside a TIM tube. The camera also has a new user interface that allows for remote control and data acquisition. The system has been outfitted with a new sensor package that gives the user more operational awareness and control.
Marley, E. V. [Physics and Life Science, Lawrence Livermore National Laboratory, M.S. L-490, Livermore, California 94550 (United States); University of California Davis, One Shields Avenue, Davis, California 95616 (United States); Shepherd, R.; Fulkerson, S.; James, L.; Emig, J.; Norman, D. [Physics and Life Science, Lawrence Livermore National Laboratory, M.S. L-490, Livermore, California 94550 (United States)
X-ray Microscopy and Imaging: 2-BM
BM BM Introduction The 2-BM beamline offers measurement capabilities for x-ray microtomography, x-ray topography and x-ray microdiffraction. X-ray microtomography and x-ray diffraction instruments are installed on separate optical tables for independent operation with fast switch over time. Optically-coupled high-resolution CCD system is used for microtomography and topography with up to 1 micron spatial resolution. X-ray microdiffraction setup consists of KB microfocussing mirrors (~3 micron minimum spot), four-circle Huber diffractometer, high-precision translation sample stage, two orthogonally-mounted video cameras for viewing sample, fluorescence detector (Si-drift diode) and diffraction detector (a scintillation detector or a CCD). Three different levels of monochromaticity are available. Conventional monochromatic x-rays from a double-bounced Si (111) crystal monochromator (DCM, D E/E=1E-4), wide band-pass monochromatic x-rays from a double multilayer monochromator (DMM, D E/E=1~4E-2) and pink beam. The available x-ray range is from 5 keV to 30 keV. The lower limit is due to the x-ray windows and the upper limit is due to the critical angle of the x-ray mirror. Two different coatings (Cr and Pt) for the x-ray mirror allow either 20 keV or 30 keV energy cutoff.
Phase Contrast Microscopy with Soft and Hard X-rays
Calibration Uses up part of dynamic range · Solution: Soft x-rays: Back side Illumination Hard xPhase Contrast Microscopy with Soft and Hard X-rays Using a Segmented Detector Benjamin Hornberger Phase Contrast 101 · A Segmented Detector for Hard X-ray Microprobes Segmented Silicon Chip Charge
Homes, Christopher C.
Quantitative Analysis of Mt. St. Helens Ash by X-Ray Diffraction and X-Ray Fluorescence Spectrometry
A quantitative study by x-ray diffraction, optical polarizing microscopy, and x-ray fluorescence spectrometry of fallout and ambient ash from three Mt. St. Helens eruptions has revealed a consistent picture of the mineralogical and elemental ...
Briant L. Davis; L. Ronald Johnson; Dana T. Griffen; William Revell Phillips; Robert K. Stevens; David Maughan
A numerical method for obtaining the fine structure of X-ray spectra
A numerical method based on techniques of inverse Fourier convolution and nonlinear least square algorithm, etc., is presented for obtaining high-resolved X-ray spectra of laser plasmas, which can eliminate the line-broadening induced by radiation sources and spectrographs, and can improve the spectral resolving power of spectrographs. The code ESDAP has now been successfully applied to the analysis of spectra from line-shaped Mg and CaF2 laser plasmas.
Zhang Lingqing; Han Shensheng; Jiang Chunhong; Xu Zhizhan; Zhang Zhengquan; Sun Lan [Shanghai Institute of Optics and Fine Mechanics, P. O. Box 800-211, Shanghai 201800 (China)
Non-Invasive Early Detection and Molecular Analysis of Low X-ray Dose
Invasive Early Detection & Molecular Analysis of Low X-ray Dose Effects Invasive Early Detection & Molecular Analysis of Low X-ray Dose Effects in the Lens Lee Goldstein Boston University School of Medicine Abstract Purpose: The lens is a highly-ordered tissue with unique optical properties and exquisite radiosensitivity. The focus of this project is to evaluate radiation cataract dose response and mechanisms associated with low-linear energy transfer (LET) X-rays. We aim to investigate the natural history of Rayleigh light scattering changes in pre-cataractous lenses of mice exposed to radiations using a fully-validated, performance-tested quasi-elastic light scattering (QLS) instrument developed by Dr. Goldstein and colleagues at Boston University. This innovative laser-based technology quantitatively assays pre-cataractous molecular pathology in the lenses of living mice
Response Time Measurements of the NIF DANTE XRD-31 X-Ray Diodes (Pre-print)
The XRD-31 is a fast, windowless X-ray vacuum photodiode developed by EG&G. It is currently the primary fast X-ray detector used to diagnose the X-rays on NIF and OMEGA on the multichannel DANTE spectrometer. The XRD-31 has a dynamic range of less than 1e-12 amps to more than 10 amps. A technique is described to measure the impulse response of the diodes to a 150 fs pulse of 200 nm laser light and a method to calculate the �risetime� for a square pulse and compare it with the computed electron transit time from the photocathode to the anode. Measured response time for 5 XRD-31s assembled in early 2004 was 149.7 ps +-2.75 ps.
Don Pellinen and Michael Griffin
X-Ray Imaging Crystal Spectrometer for Extended X-Ray Sources
Spherically or toroidally curved, double focusing crystals are used in a spectrometer for X-ray diagnostics of an extended X-ray source such as a hot plasma produced in a tokamak fusion experiment to provide spatially and temporally resolved data on plasma parameters such as ion temperature, toroidal and poloidal rotation, electron temperature, impurity ion charge-state distributions, and impurity transport. The imaging properties of these spherically or toroidally curved crystals provide both spectrally and spatially resolved X-ray data from the plasma using only one small spherically or toroidally curved crystal, thus eliminating the requirement for a large array of crystal spectrometers and the need to cross-calibrate the various crystals.
Bitter, Manfred L.; Fraekel, Benjamin; Gorman, James L.; Hill, Kenneth W.; Roquemore, Lane A.; Stodiek, Wolfgang; Goeler, Schweickhard von
Calibrating X-ray Imaging Devices for Accurate Intensity Measurement
The purpose of the project presented is to develop methods to accurately calibrate X-ray imaging devices. The approach was to develop X-ray source systems suitable for this endeavor and to develop methods to calibrate solid state detectors to measure source intensity. NSTec X-ray sources used for the absolute calibration of cameras are described, as well as the method of calibrating the source by calibrating the detectors. The work resulted in calibration measurements for several types of X-ray cameras. X-ray camera calibration measured efficiency and efficiency variation over the CCD. Camera types calibrated include: CCD, CID, back thinned (back illuminated), front illuminated.
Haugh, M. J.
Image plates as x-ray detectors in plasma physics experiments
The performance of image plates based on the photostimulable phosphor BaF(Br,l):Eu{sup 2+} has been investigated and compared with x-ray film. Evaluation of detective quantum efficiency (DQE), sensitivity, dynamic range, and linearity was carried out for several types of commercially available image plate, using the Excalibur soft x-ray calibration facility at AWE. Image plate response was found to be linear over a dynamic range of 5 orders of magnitude. One type of image plate was found to have a number of advantages for soft x-ray detection, with a measured sensitivity 1 order of magnitude greater than that of Kodak Industrex CX and DEF-5 x-ray film. The DQE of this plate was found to be superior to that of film at low [less than 10{sup 3} photons/(50 {mu}m){sup 2}] and high fluxes [greater than 10{sup 4} photons/(50 {mu}m){sup 2}]. The spatial resolution of image plates, scanned with several models of commercial image plate readers, has been evaluated using a USAF resolution test target. The highest spatial resolution measured is 35 {mu}m. Though this is significantly lower than the resolution possible with film, it is sufficient for many applications. Image plates were fielded in a refractive x-ray lens imaging diagnostic on the 1 TW Helen laser and these results are discussed.
Gales, S.G.; Bentley, C.D. [AWE Aldermaston, Reading RG7 4PR (United Kingdom)
Apparatus for monitoring x-ray beam alignment
A self-contained, hand-held apparatus is provided for monitoring alignment of an x-ray beam in an instrument employing an x-ray source. The apparatus includes a transducer assembly containing a photoresistor for providing a range of electrical signals responsive to a range of x-ray beam intensities from the x-ray beam being aligned. A circuit, powered by a 7.5 VDC power supply and containing an audio frequency pulse generator whose frequency varies with the resistance of the photoresistor, is provided for generating a range of audible sounds. A portion of the audible range corresponds to low x-ray beam intensity. Another portion of the audible range corresponds to high x-ray beam intensity. The transducer assembly may include an a photoresistor, a thin layer of x-ray fluorescent material, and a filter layer transparent to x-rays but opaque to visible light. X-rays from the beam undergoing alignment penetrate the filter layer and excite the layer of fluorescent material. The light emitted from the fluorescent material alters the resistance of the photoresistor which is in the electrical circuit including the audio pulse generator and a speaker. In employing the apparatus, the x-ray beam is aligned to a complete alignment by adjusting the x-ray beam to produce an audible sound of the maximum frequency.
Photon Sciences | Beamlines | HXN: Hard X-ray Nanoprobe
HXN: Hard X-ray Nanoprobe HXN: Hard X-ray Nanoprobe Poster | Fact Sheet | Preliminary Design Report Scientific Scope The Hard X-ray Nanoprobe beamline and endstation instruments (HXN) will be designed and constructed to explore new frontiers of hard x-ray microscopy applications with the highest achievable spatial resolution. Currently the available spatial resolution for scientific applications, provided by scanning x-ray microscopes in the hard x-ray regime, is limited to ~50nm, which is still insufficient for probing the nanoscale interfacial structures critical in determining properties and functionalities of material and biological systems. The HXN beamline aims to enable x-ray experiments at spatial resolutions ranging from 10 to 30 nm with an ultimate goal of ~1 nm. Beamline Description
Introduction to Neutron and X-Ray Scattering
Scattering Studies of Thin Scattering Studies of Thin Polymer Films Introduction to Neutron and X-Ray Scattering Sunil K. Sinha UCSD/LANL Acknowledgements: Prof. R.Pynn( Indiana U.) Prof. M.Tolan (U. Dortmund) Wilhelm Conrad Röntgen 1845-1923 1895: Discovery of X-Rays 1901 W. C. Röntgen in Physics for the discovery of x-rays. 1914 M. von Laue in Physics for x-ray diffraction from crystals. 1915 W. H. Bragg and W. L. Bragg in Physics for crystal structure determination. 1917 C. G. Barkla in Physics for characteristic radiation of elements. 1924 K. M. G. Siegbahn in Physics for x-ray spectroscopy. 1927 A. H. Compton in Physics for scattering of x-rays by electrons. 1936 P. Debye in Chemistry for diffraction of x-rays and electrons in gases.
Direct detection of x-rays for protein crystallography
An apparatus and method for directly determining the crystalline structure of a protein crystal. The crystal is irradiated by a finely collimated x-ray beam. The interaction o f the x-ray beam with the crystal produces scattered x-rays. These scattered x-rays are detected by means of a large area, thick CCD which is capable of measuring a significant number of scattered x-rays which impact its surface. The CCD is capable of detecting the position of impact of the scattered x-ray on the surface of the CCD and the quantity of scattered x-rays which impact the same cell or pixel. This data is then processed in real-time and the processed data is outputted to produce an image of the structure of the crystal. If this crystal is a protein the molecular structure of the protein can be determined from the data received.
Atac, Muzaffer; McKay, Timothy
Energy Research, Office of High Energy and Nuclear Physics,Energy Research, Office of High Energy and Nuclear Physics,
An Efficient Microwave Power Source: Free-electron Laser Afterburner
Office of High Energy and Nuclear Physics, Division of High EnergyOffice of High Energy and Nuclear Physics, Division of High EnergyOffice of High Energy and Nuclear Physics, Division of High Energy
Having produced 14 kW of average power at {approx}2 microns, JLAB has shifted its focus to the ultraviolet portion of the spectrum. This presentation will describe the JLab UV Demo FEL, present specifics of its driver ERL, and discuss the latest experimental results from FEL experiments and machine operations.
Douglas, David; Evtushenko, Pavel; Gubeli, Joseph; Hernandez-Garcia, Carlos; Legg, Robert; Neil, George; Powers, Thomas; Shinn, Michelle D; Tennant, Christopher
is on-going, but no "user facilities" can be expected inbe on constructing user facilities. In the short wavelengthtechnology. IR FEL User Facilities IR FELs have been built
Beam Conditioning and Harmonic Generation in Free Electron Lasers
Meth. A 429, 243 (1999). LCLS Design Study Group, ReportFELs) such as Euro- XFEL and LCLS are to be devices whichproposed at Euro-XFEL or the LCLS, are designed to generate
Charman, A.E.; Penn, G.; Wolski, A.; Wurtele, J.S.
A Plasma Channel Beam Conditioner for a Free Electron Laser
Nature 445, 6741 (2007). [7] LCLS Design Study Group, SLACLinac Coherent Light Source (LCLS) [7]. One example has thefunction in the FEL. For LCLS parameters, the corresponding
Penn, G.; Sessler, A.M.; Wurtele, J.S.
Advanced Free Electron Laser Facility - Los Alamos National Lab ...
The AFEL Facility is used for applications requiring high-brightness electron beams or a tunable source of high-energy infrared light pulses in the wavelength range ...
X-ray chemistry in envelopes around young stellar objects
We present chemical models of the envelope of a young stellar object (YSO) exposed to a central X-ray source. The models are applied to the massive star-forming region AFGL 2591 for different X-ray fluxes. The total X-ray ionization rate is dominated by the `secondary' ionization rate of H2 resulting from fast electrons. The carbon, sulphur and nitrogen chemistries are discussed. It is found that He+ and H3+ are enhanced and trigger a peculiar chemistry. Several molecular X-ray tracers are found and compared to tracers of the far ultraviolet (FUV) field. Like ultraviolet radiation fields, X-rays enhance simple hydrides, ions and radicals. In contrast to ultraviolet photons, X-rays can penetrate deep into the envelope and affect the chemistry even at large distances from the source. Whereas the FUV enhanced species cover a region of 200-300 AU, the region enhanced by X-rays is >1000 AU. Best-fit models for AFGL 2591 predict an X-ray luminosity LX > 1e+31 ergs/s with a hard X-ray spectrum TX > 3e+07 K. Furthermore, we find LX/Lbol ~ 1e-6. The chemistry of the bulk of the envelope mass is dominated by cosmic-ray induced reactions rather than by X-ray induced ionization for X-ray luminosities LX < 1e+33 ergs/s. The calculated line intensities of HCO+ and HCS+ show that high-J lines are more affected than lower J lines by the presence of X-rays due to their higher critical densities, and that such differences are detectable even with large aperture single-dish telescopes. Future instruments such as Herschel-HIFI or SOFIA will be able to observe X-ray enhanced hydrides whereas the sensitivity and spatial resolution of ALMA is well-suited to measure the size and geometry of the region affected by X-rays.
P. Staeuber; S. D. Doty; E. F. van Dishoeck; A. O. Benz
X-ray imaging with grazing-incidence microscopes developed for the LIL program
This article describes x-ray imaging with grazing-incidence microscopes, developed for the experimental program carried out on the Ligne d'Integration Laser (LIL) facility [J. P. Le Breton et al., Inertial Fusion Sciences and Applications 2001 (Elsevier, Paris, 2002), pp. 856-862] (24 kJ, UV--0.35 nm). The design includes a large target-to-microscope (400-700 mm) distance required by the x-ray ablation issues anticipated on the Laser MegaJoule facility [P. A. Holstein et al., Laser Part. Beams 17, 403 (1999)] (1.8 MJ) which is under construction. Two eight-image Kirkpatrick-Baez microscopes [P. Kirkpatrick and A. V. Baez J. Opt. Soc. Am. 38, 766 (1948)] with different spectral wavelength ranges and with a 400 mm source-to-mirror distance image the target on a custom-built framing camera (time resolution of {approx}80 ps). The soft x-ray version microscope is sensitive below 1 keV and its spatial resolution is better than 30 {mu}m over a 2-mm-diam region. The hard x-ray version microscope has a 10 {mu}m resolution over an 800-{mu}m-diam region and is sensitive in the 1-5 keV energy range. Two other x-ray microscopes based on an association of toroidal/spherical surfaces (T/S microscopes) produce an image on a streak camera with a spatial resolution better than 30 {mu}m over a 3 mm field of view in the direction of the camera slit. Both microscopes have been designed to have, respectively, a maximum sensitivity in the 0.1-1 and 1-5 keV energy range. We present the original design of these four microscopes and their test on a dc x-ray tube in the laboratory. The diagnostics were successfully used on LIL first experiments early in 2005. Results of soft x-ray imaging of a radiative jet during conical shaped laser interaction are shown.
Rosch, R.; Boutin, J. Y.; Le Breton, J. P.; Gontier, D.; Jadaud, J. P.; Reverdin, C.; Soullie, G.; Lidove, G.; Maroni, R. [CEA/DIF, BP 12, 91680 Bruyeres-Le-Chatel (France)
Proton induced quasi-monochromatic x-ray beams for soft x-ray spectroscopy studies and selective x-ray fluorescence analysis
We present the analytical features and performance of an x-ray spectroscopy end station of moderate energy resolution operating with proton-induced quasi-monochromatic x-ray beams. The apparatus was designed, installed and operated at the 5.5 MV Tandem VdG Accelerator Laboratory of the Institute of Nuclear Physics, N.C.S.R. 'Demokritos,' Athens. The setup includes a two-level ultrahigh vacuum chamber that hosts in the lower level up to six primary targets in a rotatable holder; there, the irradiation of pure element materials-used as primary targets-with few-MeV high current ({approx}{mu}A) proton beams produces intense quasi-monochromatic x-ray beams of selectable energy. In the chamber's upper level, a six-position rotatable sample holder hosts the targets considered for x-ray spectroscopy studies. The proton-induced x-ray beam, after proper collimation, is guided to the sample position whereas various filters can be also inserted along the beam's path to eliminate the backscattered protons or/and to absorb selectively components of the x-ray beam. The apparatus incorporates an ultrathin window Si(Li) spectrometer (FWHM 136 eV at 5.89 keV) coupled with low-noise electronics capable of efficiently detecting photons down to carbon K{alpha}. Exemplary soft x-ray spectroscopy studies and results of selective x-ray fluorescence analysis are presented.
Sokaras, D. [Institute of Nuclear Physics, N.C.S.R. Demokritos, Aghia Paraskevi, 15310 Athens (Greece); Zarkadas, Ch. [PANalytical B.V., 7600 AA Almelo (Netherlands); Fliegauf, R.; Beckhoff, B. [Physikalisch-Technische Bundesanstalt, Abbestrasse 2-12, 10587 Berlin (Germany); Karydas, A. G. [Institute of Nuclear Physics, N.C.S.R. Demokritos, Aghia Paraskevi, 15310 Athens (Greece); Nuclear Spectrometry and Applications Laboratory, IAEA Laboratories, A-2444 Seibersdorf (Austria)
Operation of a Single-Photon-Counting X-Ray Charge-Coupled Device Camera Spectrometer in a Petawatt Environment
The use of a single-photon-counting x-ray CCD (charge-coupled device) camera as an x-ray spectrometer is a well-established technique in ultrashort-pulse laser experiments. In single-photon-counting mode, the pixel value of each readout pixel is proportional to the energy deposited from the incident x-ray photon. For photons below 100 keV, a significant fraction of the events deposits all the energy in a single pixel. A histogram of the pixel readout values gives a good approximation of the x-ray spectrum. This technique requires almost no alignment, but it is very sensitive to signal-to-background issues, especially in a high-energy petawatt environment.
Stoeckl, C.; Theobald, W.; Sangster, T.C.; Key, M.H.; Patel, P.; Zhang, B.B.; Clarke, R.; Karsch, S.; Norreys, P.
Applications of Diagnostic X-ray Spectrometers
... produced plasmas, terawatt pulsed accelerators, electron cyclotron resonance ion sources, electron-beam ion traps, intense ultrafast laser sources ...
Gray scale x-ray mask
The present invention describes a method for fabricating an embossing tool or an x-ray mask tool, providing microstructures that smoothly vary in height from point-to-point in etched substrates, i.e., structure which can vary in all three dimensions. The process uses a lithographic technique to transfer an image pattern in the surface of a silicon wafer by exposing and developing the resist and then etching the silicon substrate. Importantly, the photoresist is variably exposed so that when developed some of the resist layer remains. The remaining undeveloped resist acts as an etchant barrier to the reactive plasma used to etch the silicon substrate and therefore provides the ability etch structures of variable depths.
Morales, Alfredo M. (Livermore, CA); Gonzales, Marcela (Seattle, WA)
Photon Sciences | Beamlines | IXS: Inelastic X-ray Scattering
IXS: Inelastic X-ray Scattering IXS: Inelastic X-ray Scattering Poster | Fact Sheet | Preliminary Design Report Scientific Scope Many hot topics related to the high frequency dynamics of condensed matter require both a narrower and steeper resolution function and access to a broader dynamic range than what are currently available. This represents a sort of "no man's land" that falls right in the dynamic gap lying between the high frequency spectroscopies, such as inelastic x-ray scattering (IXS), and the low frequency ones. New IXS spectrometers with improved energy and momentum resolutions would be required to fill this gap. To achieve this goal, a new x-ray optics concept for both the monochromatization and energy analysis of x-rays will be implemented at the NSLS-II Inelastic X-ray Scattering beamline. This solution exploits the
X-Ray Fluorescence (XRF) | Open Energy Information
Open Energy Info (EERE)
X-Ray Fluorescence (XRF) X-Ray Fluorescence (XRF) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Technique: X-Ray Fluorescence (XRF) Details Activities (0) Areas (0) Regions (0) NEPA(0) Exploration Technique Information Exploration Group: Lab Analysis Techniques Exploration Sub Group: Rock Lab Analysis Parent Exploration Technique: Rock Lab Analysis Information Provided by Technique Lithology: Bulk and trace element analysis of rocks, minerals, and sediments. Stratigraphic/Structural: Hydrological: Thermal: Dictionary.png X-Ray Fluorescence (XRF): X-Ray Fluorescence is a lab-based technique used for bulk chemical analysis of rock, mineral, sediment, and fluid samples. The technique depends on the fundamental principles of x-ray interactions with solid materials, similar
X-Ray Diffraction Microscopy of Magnetic Structures
X-Ray Diffraction Microscopy of Magnetic Structures Print X-Ray Diffraction Microscopy of Magnetic Structures Print science brief icon Scientists working at ALS Beamline 126.96.36.199 have demonstrated a new x-ray technique for producing short-exposure nanoscale images of the magnetic structure of materials. The new method combines aspects of coherent x-ray diffraction, which can determine 3-D charge distributions, and resonant magnetic scattering, which is sensitive to magnetic structures. Physicists have used coherent x-ray diffraction to measure the electron density of complicated molecules. The formula used to make these calculations contains terms that relate to the electron spin of magnetic atoms, but these terms are traditionally ignored since coherent x-ray diffraction has not been used to retrieve magnetic information. Using the full formula allows for the determination of not only the electron density, but also the magnetic spin distribution and its orientation.
Biological Imaging by Soft X-Ray Diffraction Microscopy Print Biological Imaging by Soft X-Ray Diffraction Microscopy Print Electron and x-ray microscopes are a valuable tool for both the life and materials sciences, but they are limited in their ability to image with nanometer-scale resolution in three dimensions nonperiodic objects that are several microns in size. To fill this gap, the technique of coherent x-ray diffraction imaging now under development takes advantage of the penetrating power of x rays while simultaneously removing the limitations imposed by lens-based optical systems. Researchers from Stony Brook University, in collaboration with scientists at the ALS and Cornell University, have taken a large step in this direction by using a lensless x-ray diffraction microscope to image a freeze-dried yeast cell to better than 30-nm resolution. Images were made at several angular orientations of the cell.
Definition: X-Ray Diffraction (XRD) | Open Energy Information
X-Ray Diffraction (XRD) X-Ray Diffraction (XRD) Jump to: navigation, search Dictionary.png X-Ray Diffraction (XRD) X-Ray Diffraction (XRD) is a laboratory-based technique commonly used for identification of crystalline materials and analysis of unit cell dimensions. One of two primary types of XRD analysis (X-ray powder diffraction and single-crystal XRD) is commonly applied to samples to obtain specific information about the crystalline material under investigation. X-ray powder diffraction is widely used in geology, environmental science, material science, and engineering to rapidly identify unknown crystalline substances (typically in less than 20 minutes). A pure, finely ground, and homogenized sample is required for determination of the bulk composition. Additional uses include detailed
X-Ray Diffraction (XRD) | Open Energy Information
X-Ray Diffraction (XRD) X-Ray Diffraction (XRD) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Technique: X-Ray Diffraction (XRD) Details Activities (0) Areas (0) Regions (0) NEPA(0) Exploration Technique Information Exploration Group: Lab Analysis Techniques Exploration Sub Group: Rock Lab Analysis Parent Exploration Technique: Rock Lab Analysis Information Provided by Technique Lithology: Rapid and unambiguous identification of unknown minerals.[1] Stratigraphic/Structural: Hydrological: Thermal: Dictionary.png X-Ray Diffraction (XRD): X-Ray Diffraction (XRD) is a laboratory-based technique commonly used for identification of crystalline materials and analysis of unit cell dimensions. One of two primary types of XRD analysis (X-ray powder diffraction and single-crystal XRD) is commonly applied to samples to
Portable X-Ray Diffraction (XRD) | Open Energy Information
Portable X-Ray Diffraction (XRD) Portable X-Ray Diffraction (XRD) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Technique: Portable X-Ray Diffraction (XRD) Details Activities (0) Areas (0) Regions (0) NEPA(0) Exploration Technique Information Exploration Group: Field Techniques Exploration Sub Group: Data Collection and Mapping Parent Exploration Technique: Data Collection and Mapping Information Provided by Technique Lithology: Rapid and unambiguous identification of unknown minerals.[1] Stratigraphic/Structural: Hydrological: Thermal: Dictionary.png Portable X-Ray Diffraction (XRD): Portable X-Ray Diffraction (XRD) is a field-based technique that can be used for identification of crystalline materials and analysis of unit cell dimensions. Portable XRD analysis is similar to X-ray powder diffraction,
Fabrication process for a gradient index x-ray lens
A process for fabricating high efficiency x-ray lenses that operate in the 0.5-4.0 keV region suitable for use in biological imaging, surface science, and x-ray lithography of integrated circuits. The gradient index x-ray optics fabrication process broadly involves co-sputtering multi-layers of film on a wire, followed by slicing and mounting on block, and then ion beam thinning to a thickness determined by periodic testing for efficiency. The process enables the fabrication of transmissive gradient index x-ray optics for the 0.5-4.0 keV energy range. This process allows the fabrication of optical elements for the next generation of imaging and x-ray lithography instruments m the soft x-ray region.
Bionta, Richard M. (Livermore, CA); Makowiecki, Daniel M. (Livermore, CA); Skulina, Kenneth M. (Livermore, CA)
A process is disclosed for fabricating high efficiency x-ray lenses that operate in the 0.5-4.0 keV region suitable for use in biological imaging, surface science, and x-ray lithography of integrated circuits. The gradient index x-ray optics fabrication process broadly involves co-sputtering multi-layers of film on a wire, followed by slicing and mounting on block, and then ion beam thinning to a thickness determined by periodic testing for efficiency. The process enables the fabrication of transmissive gradient index x-ray optics for the 0.5-4.0 keV energy range. This process allows the fabrication of optical elements for the next generation of imaging and x-ray lithography instruments in the soft x-ray region. 13 figures.
Bionta, R.M.; Makowiecki, D.M.; Skulina, K.M.
APS 7-BM Beamline: X-Ray Resources
Useful Websites Useful Websites X-Ray Interactions with Matter from CRXO at LBNL. Intuitive interface for x-ray transmission and reflectivity for a wide range of materials. X-Ray Data Booklet from LBNL. Slightly outdated in places, but many useful tables of edge energies, fluorescence lines, and crystal lattice spacings. NIST XCOM Database. Powerful database of photoelectric absorption, elastic scattering, and Compton scattering cross-sections for a wide range of materials. X-Ray Server. Maintained by Sergey Stepanov at GMCA at the APS, this website has several powerful calculators for simulating x-ray reflection and diffraction. Software X-Ray Oriented Programs (XOP). This program, written by scientists at the ESRF and APS, is widely used in the synchrotron research community.
Biological Imaging by Soft X-Ray Diffraction Microscopy Print Biological Imaging by Soft X-Ray Diffraction Microscopy Print Electron and x-ray microscopes are a valuable tool for both the life and materials sciences, but they are limited in their ability to image with nanometer-scale resolution in three