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Sample records for repetition rate x-ray

  1. Studies of a Linac Driver for a High Repetition Rate X-Ray FEL

    Energy Technology Data Exchange (ETDEWEB)

    Venturini, M.; Corlett, J.; Doolittle, L.; Filippetto, D.; Papadopoulos, C.; Penn, G.; Prosnitz, D.; Qiang, J.; Reinsch, M.; Ryne, R.; Sannibale, F.; Staples, J.; Wells, R.; Wurtele, J.; Zolotorev, M.; Zholents, A.

    2011-06-01

    We report on on-going studies of a superconducting CW linac driver intended to support a high repetition rate FEL operating in the soft x-rays spectrum. We present a pointdesign for a 1.8 GeV machine tuned for 300 pC bunches and delivering low-emittance, low-energy spread beams as needed for the SASE and seeded beamlines.

  2. Compact X-ray Source using a High Repetition Rate Laser and Copper Linac

    CERN Document Server

    Graves, W S; Brown, P; Carbajo, S; Dolgashev, V; Hong, K -H; Ihloff, E; Khaykovich, B; Lin, H; Murari, K; Nanni, E A; Resta, G; Tantawi, S; Zapata, L E; Kärtner, F X; Moncton, D E

    2014-01-01

    A design for a compact x-ray light source (CXLS) with flux and brilliance orders of magnitude beyond existing laboratory scale sources is presented. The source is based on inverse Compton scattering of a high brightness electron bunch on a picosecond laser pulse. The accelerator is a novel high-efficiency standing-wave linac and RF photoinjector powered by a single ultrastable RF transmitter at x-band RF frequency. The high efficiency permits operation at repetition rates up to 1 kHz, which is further boosted to 100 kHz by operating with trains of 100 bunches of 100 pC charge, each separated by 5 ns. The 100 kHz repetition rate is orders of magnitude beyond existing high brightness copper linacs. The entire accelerator is approximately 1 meter long and produces hard x-rays tunable over a wide range of photon energies. The colliding laser is a Yb:YAG solid-state amplifier producing 1030 nm, 100 mJ pulses at the same 1 kHz repetition rate as the accelerator. The laser pulse is frequency-doubled and stored for m...

  3. A HIGH REPETITION RATE VUV-SOFT X-RAY FEL CONCEPT

    Energy Technology Data Exchange (ETDEWEB)

    Corlett, J.; Byrd, J.; Fawley, W.M.; Gullans, M.; Li, D.; Lidia,S.M.; Padmore, H.; Penn, G.; Pogorelov, I.; Qiang, J.; Robin, D.; Sannibale, F.; Staples, J.W.; Steier, C.; Venturini, M.; Virostek, S.; Wan, W.; Wells, R.; Wilcox, R.; Wurtele, J.; Zholents, A.

    2007-06-24

    We report on design studies for a seeded FEL light source that is responsive to the scientific needs of the future. The FEL process increases radiation flux by several orders of magnitude above existing incoherent sources, and offers the additional enhancements attainable by optical manipulations of the electron beam: control of the temporal duration and bandwidth of the coherent output, reduced gain length in the FEL, utilization of harmonics to attain shorter wavelengths, and precise synchronization of the x-ray pulse with seed laser systems. We describe an FEL facility concept based on a high repetition rate RF photocathode gun, that would allow simultaneous operation of multiple independent FEL's, each producing high average brightness, tunable over the VUV-soft x-ray range, and each with individual performance characteristics determined by the configuration of the FEL. SASE, enhanced-SASE (ESASE), seeded, harmonic generation, and other configurations making use of optical manipulations of the electron beam may be employed, providing a wide range of photon beam properties to meet varied user demands.

  4. Performance Optimization of a High-Repetition-Rate KrF Laser Plasma X-Ray Source for Microlithography.

    Science.gov (United States)

    Bukerk, F; Louis, E; Turcu, E C; Tallents, G J; Batani, D

    1992-01-01

    In order to develop a high-intensity laser plasma x-ray source appropriate for industrial application of x-ray lithography, experiments have been carried out using a high-repetition-rate (up to 40 Hz) excimer laser (249 nm, 300 mJ) with a power density of 2 × 1013 W/ cm2 in the laser focus. In this study emphasis is given to remedying specific problems inherent in operating the laser plasma x-ray source at high repetition rates and in its prolonged operation. Two different methods of minimizing the production of target debris are investigated. First, the use of helium as a quenching gas results in a reduction of the amount of atomic debris particles by more than two orders of magnitude with negligible x-ray absorption. Second, a tape target as opposed to a solid target reduces the production of larger debris particles by a further factor of 100. Remaining debris is stopped by an aluminized plastic or beryllium filter used to avoid exposure of the resist by plasma ultraviolet radiation. The x-ray source has been used to image x-ray transmission mask structures down to 0.3 μm onto general purpose x-ray photo-resist. Results have been analyzed with SEM. The x-ray emission spectrum of the repetitive laser plasmas created from an iron target has been recorded and the conversion efficiency of the laser light into x-rays that contribute to exposure of the resist was measured to be 0.3% over 2π sr.

  5. Ultra-high-resolution inelastic X-ray scattering at high-repetition-rate self-seeded X-ray free-electron lasers

    Energy Technology Data Exchange (ETDEWEB)

    Chubar, Oleg [Brookhaven National Laboratory, Upton, NY 11973 (United States); Geloni, Gianluca [European X-ray Free-Electron Laser, Albert-Einstein-Ring 19, 22761 Hamburg (Germany); Kocharyan, Vitali [Deutsches Elektronen-Synchrotron, 22761 Hamburg (Germany); Madsen, Anders [European X-ray Free-Electron Laser, Albert-Einstein-Ring 19, 22761 Hamburg (Germany); Saldin, Evgeni; Serkez, Svitozar [Deutsches Elektronen-Synchrotron, 22761 Hamburg (Germany); Shvyd’ko, Yuri, E-mail: shvydko@aps.anl.gov [Argonne National Laboratory, Argonne, IL 60439 (United States); Sutter, John [Diamond Light Source Ltd, Didcot OX11 0DE (United Kingdom)

    2016-02-12

    This article explores novel opportunities for ultra-high-resolution inelastic X-ray scattering (IXS) at high-repetition-rate self-seeded XFELs. These next-generation light sources are promising a more than three orders of magnitude increase in average spectral flux compared with what is possible with storage-ring-based radiation sources. In combination with the advanced IXS spectrometer described here, this may become a real game-changer for ultra-high-resolution X-ray spectroscopies, and hence for the studies of dynamics in condensed matter systems. Inelastic X-ray scattering (IXS) is an important tool for studies of equilibrium dynamics in condensed matter. A new spectrometer recently proposed for ultra-high-resolution IXS (UHRIX) has achieved 0.6 meV and 0.25 nm{sup −1} spectral and momentum-transfer resolutions, respectively. However, further improvements down to 0.1 meV and 0.02 nm{sup −1} are required to close the gap in energy–momentum space between high- and low-frequency probes. It is shown that this goal can be achieved by further optimizing the X-ray optics and by increasing the spectral flux of the incident X-ray pulses. UHRIX performs best at energies from 5 to 10 keV, where a combination of self-seeding and undulator tapering at the SASE-2 beamline of the European XFEL promises up to a 100-fold increase in average spectral flux compared with nominal SASE pulses at saturation, or three orders of magnitude more than what is possible with storage-ring-based radiation sources. Wave-optics calculations show that about 7 × 10{sup 12} photons s{sup −1} in a 90 µeV bandwidth can be achieved on the sample. This will provide unique new possibilities for dynamics studies by IXS.

  6. Intense high repetition rate Mo Kα x-ray source generated from laser solid interaction for imaging application

    Energy Technology Data Exchange (ETDEWEB)

    Huang, K.; Li, M. H.; Yan, W. C.; Ma, Y.; Zhao, J. R.; Li, Y. F.; Chen, L. M., E-mail: lmchen@iphy.ac.cn [Beijing National Laboratory of Condensed Matter Physics, Institute of Physics, CAS, Beijing 100190 (China); Guo, X. [Beijing National Laboratory of Condensed Matter Physics, Institute of Physics, CAS, Beijing 100190 (China); Department of Physics, Shanghai Jiao Tong University, Shanghai 200240 (China); School of Optoelectronics, Beijing Institute of Technology, Beijing 100081 (China); Li, D. Z. [Institute of High Energy Physics, CAS, Beijing 100049 (China); Chen, Y. P.; Zhang, J. [Department of Physics, Shanghai Jiao Tong University, Shanghai 200240 (China)

    2014-11-15

    We report an efficient Mo Kα x-ray source produced by interaction of femtosecond Ti: sapphire laser pulses with a solid Molybdenum target working at 1 kHz repetition rate. The generated Mo Kα x-ray intensity reaches to 4.7 × 10{sup 10} photons sr{sup −1} s{sup −1}, corresponding to an average power of 0.8 mW into 2π solid angle. The spatial resolution of this x-ray source is measured to be 26 lp/mm. With the high flux and high spatial resolution characteristics, high resolving in-line x-ray radiography was realized on test objects and large size biological samples within merely half a minute. This experiment shows the possibility of laser plasma hard x-ray source as a new low cost and high resolution system for radiography and its ability of ultrafast x-ray pump-probe study of matter.

  7. Demonstration of a time-resolved x-ray scattering instrument utilizing the full-repetition rate of x-ray pulses at the Pohang Light Source

    Science.gov (United States)

    Jo, Wonhyuk; Eom, Intae; Landahl, Eric C.; Lee, Sooheyong; Yu, Chung-Jong

    2016-03-01

    We report on the development of a new experimental instrument for time-resolved x-ray scattering (TRXS) at the Pohang Light Source (PLS-II). It operates with a photon energy ranging from 5 to 18 keV. It is equipped with an amplified Ti:sappahire femtosecond laser, optical diagnostics, and laser beam delivery for pump-probe experiments. A high-speed single-element detector and high trigger-rate oscilloscope are used for rapid data acquisition. While this instrument is capable of measuring sub-nanosecond dynamics using standard laser pump/x-ray probe techniques, it also takes advantage of the dense 500 MHz standard fill pattern in the PLS-II storage ring to efficiently record nano-to-micro-second dynamics simultaneously. We demonstrate this capability by measuring both the (fast) impulsive strain and (slower) thermal recovery dynamics of a crystalline InSb sample following intense ultrafast laser excitation. Exploiting the full repetition rate of the storage ring results in a significant improvement in data collection rates compared to conventional bunch-tagging methods.

  8. Filamentation effect in a gas attenuator for high-repetition-rate X-ray FELs

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Yiping; Krzywinski, Jacek; Schafer, Donald W.; Ortiz, Eliazar; Rowen, Michael; Raubenheimer, Tor O.

    2016-01-01

    A sustained filamentation or density depression phenomenon in an argon gas attenuator servicing a high-repetition femtosecond X-ray free-electron laser has been studied using a finite-difference method applied to the thermal diffusion equation for an ideal gas. A steady-state solution was obtained by assuming continuous-wave input of an equivalent time-averaged beam power and that the pressure of the entire gas volume has reached equilibrium. Both radial and axial temperature/density gradients were found and describable as filamentation or density depression previously reported for a femtosecond optical laser of similar attributes. The effect exhibits complex dependence on the input power, the desired attenuation, and the geometries of the beam and the attenuator. Time-dependent simulations were carried out to further elucidate the evolution of the temperature/density gradients in between pulses, from which the actual attenuation received by any given pulse can be properly calculated.

  9. Fluid dynamics analysis of a gas attenuator for X-ray FELs under high-repetition-rate operation

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Bo; Wu, Juhao; Raubenheimer, Tor O.; Feng, Yiping

    2017-04-18

    Newtonian fluid dynamics simulations were performed using the Navier–Stokes–Fourier formulations to elucidate the short time-scale (µs and longer) evolution of the density and temperature distributions in an argon-gas-filled attenuator for an X-ray free-electron laser under high-repetition-rate operation. Both hydrodynamic motions of the gas molecules and thermal conductions were included in a finite-volume calculation. It was found that the hydrodynamic wave motions play the primary role in creating a density depression (also known as a filament) by advectively transporting gas particles away from the X-ray laser–gas interaction region, where large pressure and temperature gradients have been built upon the initial energy depositionviaX-ray photoelectric absorption and subsequent thermalization. Concurrent outward heat conduction tends to reduce the pressure in the filament core region, generating a counter gas flow to backfill the filament, but on an initially slower time scale. If the inter-pulse separation is sufficiently short so the filament cannot recover, the depth of the filament progressively increases as the trailing pulses remove additional gas particles. Since the rate of hydrodynamic removal decreases while the rate of heat conduction back flow increases as time elapses, the two competing mechanisms ultimately reach a dynamic balance, establishing a repeating pattern for each pulse cycle. By performing simulations at higher repetition rates but lower per pulse energies while maintaining a constant time-averaged power, the amplitude of the hydrodynamic motion per pulse becomes smaller, and the evolution of the temperature and density distributions approach asymptotically towards, as expected, those calculated for a continuous-wave input of the equivalent power.

  10. A K-alpha x-ray source using high energy and high repetition rate laser system for phase contrast imaging

    OpenAIRE

    Serbanescu, Cristina; Fourmaux, Sylvain; Kieffer, Jean-Claude; Kincaid, Russell; Krol, Andrzej

    2009-01-01

    K-alpha x-ray sources from laser produced plasmas provide completely new possibilities for x-ray phase-contrast imaging applications. By tightly focusing intense femtosecond laser pulses onto a solid target K-alpha x-ray pulses are generated through the interaction of energetic electrons created in the plasma with the bulk target. In this paper, we present a continuous and efficient Mo K-alpha x-ray source produced by a femtosecond laser system operating at 100 Hz repetition rate with maximum...

  11. A high-repetition rate scheme for synchrotron-based picosecond laser pump/x-ray probe experiments on chemical and biological systems in solution.

    Science.gov (United States)

    Lima, Frederico A; Milne, Christopher J; Amarasinghe, Dimali C V; Rittmann-Frank, Mercedes Hannelore; van der Veen, Renske M; Reinhard, Marco; Pham, Van-Thai; Karlsson, Susanne; Johnson, Steven L; Grolimund, Daniel; Borca, Camelia; Huthwelker, Thomas; Janousch, Markus; van Mourik, Frank; Abela, Rafael; Chergui, Majed

    2011-06-01

    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.

  12. Plasmon-enhanced photocathode for high brightness and high repetition rate x-ray sources

    Energy Technology Data Exchange (ETDEWEB)

    Polyakov, Aleksandr; Senft, Christoph; Thompson, K. F.; Feng, J.; Cabrini, S.; Schuck, P. J.; Padmore, Howard; Peppernick, Samuel J.; Hess, Wayne P.

    2013-02-11

    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.

  13. A K-alpha x-ray source using high energy and high repetition rate laser system for phase contrast imaging.

    Science.gov (United States)

    Serbanescu, Cristina; Fourmaux, Sylvain; Kieffer, Jean-Claude; Kincaid, Russell; Krol, Andrzej

    2009-01-01

    K-alpha x-ray sources from laser produced plasmas provide completely new possibilities for x-ray phase-contrast imaging applications. By tightly focusing intense femtosecond laser pulses onto a solid target K-alpha x-ray pulses are generated through the interaction of energetic electrons created in the plasma with the bulk target. In this paper, we present a continuous and efficient Mo K-alpha x-ray source produced by a femtosecond laser system operating at 100 Hz repetition rate with maximum pulse energy of 110 mJ before compression. The source has an x-ray conversion efficiency of greater than 10(-5) into K-alpha line emission. In preparation for phase contrast imaging applications, the size of the resultant K-alpha x-ray emission spot has been also characterized. The source exhibits sufficient spatial coherence to observe phase contrast. We observe a relatively small broadening of the K-alpha source size compared to the size of the laser beam itself. Detailed characterization of the source including the x-ray spectrum and the x-ray average yield along with phase contrast images of test objects will be presented.

  14. Soft-X-Ray Projection Lithography Using a High-Repetition-Rate Laser-Induced X-Ray Source for Sub-100 Nanometer Lithography Processes

    NARCIS (Netherlands)

    E. Louis,; F. Bijkerk,; Shmaenok, L.; Voorma, H. J.; van der Wiel, M. J.; Schlatmann, R.; Verhoeven, J.; van der Drift, E. W. J. M.; Romijn, J.; Rousseeuw, B. A. C.; Voss, F.; Desor, R.; Nikolaus, B.

    1993-01-01

    In this paper we present the status of a joint development programme on soft x-ray projection lithography (SXPL) integrating work on high brightness laser plasma sources. fabrication of multilayer x-ray mirrors. and patterning of reflection masks. We are in the process of optimization of a laser-pla

  15. Ultra-high-resolution inelastic X-ray scattering at high-repetition-rate self-seeded X-ray free-electron lasers.

    Science.gov (United States)

    Chubar, Oleg; Geloni, Gianluca; Kocharyan, Vitali; Madsen, Anders; Saldin, Evgeni; Serkez, Svitozar; Shvyd'ko, Yuri; Sutter, John

    2016-03-01

    Inelastic X-ray scattering (IXS) is an important tool for studies of equilibrium dynamics in condensed matter. A new spectrometer recently proposed for ultra-high-resolution IXS (UHRIX) has achieved 0.6 meV and 0.25 nm(-1) spectral and momentum-transfer resolutions, respectively. However, further improvements down to 0.1 meV and 0.02 nm(-1) are required to close the gap in energy-momentum space between high- and low-frequency probes. It is shown that this goal can be achieved by further optimizing the X-ray optics and by increasing the spectral flux of the incident X-ray pulses. UHRIX performs best at energies from 5 to 10 keV, where a combination of self-seeding and undulator tapering at the SASE-2 beamline of the European XFEL promises up to a 100-fold increase in average spectral flux compared with nominal SASE pulses at saturation, or three orders of magnitude more than what is possible with storage-ring-based radiation sources. Wave-optics calculations show that about 7 × 10(12) photons s(-1) in a 90 µeV bandwidth can be achieved on the sample. This will provide unique new possibilities for dynamics studies by IXS.

  16. Ultra-high-resolution inelastic X-ray scattering at high-repetition-rate self-seeded X-ray free-electron lasers

    Energy Technology Data Exchange (ETDEWEB)

    Chubar, Oleg; Geloni, Gianluca; Kocharyan, Vitali; Madsen, Anders; Saldin, Evgeni; Serkez, Svitozar; Shvyd' ko, Yuri; Sutter, John

    2016-02-12

    Inelastic X-ray scattering (IXS) is an important tool for studies of equilibrium dynamics in condensed matter. A new spectrometer recently proposed for ultra-high-resolution IXS (UHRIX) has achieved 0.6 meV and 0.25 nm-1spectral and momentum-transfer resolutions, respectively. However, further improvements down to 0.1 meV and 0.02 nm-1 are required to close the gap in energy–momentum space between high- and low-frequency probes. It is shown that this goal can be achieved by further optimizing the X-ray optics and by increasing the spectral flux of the incident X-ray pulses. UHRIX performs best at energies from 5 to 10 keV, where a combination of self-seeding and undulator tapering at the SASE-2 beamline of the European XFEL promises up to a 100-fold increase in average spectral flux compared with nominal SASE pulses at saturation, or three orders of magnitude more than what is possible with storage-ring-based radiation sources. Wave-optics calculations show that about 7 × 1012 photons s-1 in a 90 µeV bandwidth can be achieved on the sample. This will provide unique new possibilities for dynamics studies by IXS.

  17. Novel opportunities for sub-meV inelastic X-ray scattering at high-repetition rate self-seeded X-ray free-electron lasers

    Energy Technology Data Exchange (ETDEWEB)

    Chubar, Oleg [Brookhaven National Laboratory, Upton, NY (United States). National Synchrotron Light Source II; Geloni, Gianluca; Madsen, Anders [European XFEL GmbH, Hamburg (Germany); Kocharyan, Vitali; Saldin, Evgeni; Serkez, Svitozar [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Shvyd' ko, Yuri [Argonne National Laboratory, IL (United States). Advanced Photon Source; Sutter, John [Diamond Light Source Ltd., Didcot (United Kingdom)

    2015-08-15

    Inelastic X-ray scattering (IXS) is an important tool for studies of equilibrium dynamics in condensed matter. A new spectrometer recently proposed for ultra-high-resolution IXS (UHRIX) has achieved 0.6 meV and 0.25 nm{sup -1} spectral and momentum transfer resolutions, respectively. However, further improvements down to 0.1 meV and 0.02 nm{sup -1} are required to close the gap in energy-momentum space between high and low frequency probes. We show that this goal can be achieved by further optimizing the X-ray optics and by increasing the spectral flux of the incident X-ray pulses. UHRIX performs best at energies from 5 to 10 keV, where a combination of self-seeding and undulator tapering at the SASE-2 beamline of the European XFEL promises up to a hundred-fold increase in average spectral flux compared with nominal SASE pulses at saturation, or three orders of magnitude more than possible with storage-ring based radiation sources. Wave-optics propagation shows that about 7 x 10{sup 12} ph/s in a 90-μeV bandwidth can be achieved on the sample. This will provide unique new possibilities for dynamics studies by IXS.

  18. Novel opportunities for sub-meV inelastic X-ray scattering at high-repetition rate self-seeded X-ray free-electron lasers

    CERN Document Server

    Chubar, Oleg; Kocharyan, Vitali; Madsen, Anders; Saldin, Evgeni; Serkez, Svitozar; Shvyd'ko, Yuri; Sutter, John

    2015-01-01

    Inelastic X-ray scattering (IXS) is an important tool for studies of equilibrium dynamics in condensed matter. A new spectrometer recently proposed for ultra-high-resolution IXS (UHRIX) has achieved 0.6~meV and 0.25~nm$^{-1}$ spectral and momentum transfer resolutions, respectively. However, further improvements down to 0.1~meV and 0.02~nm$^{-1}$ are required to close the gap in energy-momentum space between high and low frequency probes. We show that this goal can be achieved by further optimizing the X-ray optics and by increasing the spectral flux of the incident X-ray pulses. UHRIX performs best at energies from 5 to 10 keV, where a combination of self-seeding and undulator tapering at the SASE-2 beamline of the European XFEL promises up to a hundred-fold increase in average spectral flux compared with nominal SASE pulses at saturation, or three orders of magnitude more than possible with storage-ring based radiation sources. Wave-optics propagation shows that about $7\\times 10^{12}$~ph/s in a $90$-$\\mu$e...

  19. The European X-ray Free-Electron Laser: toward an ultra-bright, high repetition-rate x-ray source

    Institute of Scientific and Technical Information of China (English)

    M.Altarelli

    2015-01-01

    The status of the European X-ray Free-Electron Laser(European XFEL), under construction near Hamburg, Germany, is described. The start of operations of the LCLS at SLAC and of SACLA in Japan has already produced impressive scientific results. The European XFEL facility is powered by a 17.5 Ge V superconducting linear accelerator that,compared to these two operating facilities, will generate two orders of magnitude more pulses per second, up to 27 000.It can therefore support modes of operation switching the beam up to 30 times per second among three different experiments, providing each of them with thousands of pulses per second. The scientific possibilities opened up by these capabilities are briefly described, together with the current instrumental developments(in optics, detectors, lasers,etc.) that are necessary to implement this program.

  20. Short-time X-ray diffraction with an efficient-optimized, high repetition-rate laser-plasma X-ray-source; Kurzzeit-Roentgenbeugung mit Hilfe einer Effizienz-optimierten, hochrepetierenden Laser-Plasma-Roentgenquelle

    Energy Technology Data Exchange (ETDEWEB)

    Kaehle, Stephan

    2009-04-23

    This thesis deals with the production and application of ultrashort X-ray pulses. In the beginning different possibilities for the production of X-ray pulses with pulse durations of below one picosecond are presented, whereby the main topic lies on the so called laser-plasma X-ray sources with high repetition rate. In this case ultrashort laser pulses are focused on a metal, so that in the focus intensities of above 10{sup 16} W/cm{sup 2} dominate. In the ideal case in such way ultrafast electrons are produced, which are responsible for line radiation. In these experiments titanium K{sub {alpha}} radiation is produced, thes photons possess an energy of 4.51 keV. For the efficient production of line radiation here the Ti:Sa laser is optimized in view of the laser energy and the pulse shape and the influence of the different parameters on the K{sub {alpha}} production systematically studied. The influences of laser intensity, system-conditioned pre-pulses and of phase modulation are checked. It turns out that beside the increasement of the K{sub {alpha}} radiation by a suited laser intensity a reduction of the X-ray background radiation is of deciding importance for the obtaining of clear diffraction images. This background radiation is mainly composed of bremsstrahlung. It can be suppressed by the avoidance of intrinsic pre-pulses and by means of 2nd-order phase modulation. By means of optical excitation and X-ray exploration experiments the production of acoustic waves after ultrashort optical excitation in a 150 nm thick Ge(111) film on Si(111) is studied. These acoustic waves are driven by thermal (in this time scale time-independent) and electronic (time dependent) pressure amounts. As essential results it turns out that the relative amount of the electronic pressure increases with decreasing excitation density. [German] Diese Arbeit befasst sich mit der Erzeugung und Anwendung ultrakurzer Roentgenimpulse. Zu Beginn werden verschiedene Moeglichkeiten zur

  1. 基于光导开关的重复频率闪光X光机%Repetitive rate flash X-ray generator with photo conductive semiconductor switches

    Institute of Scientific and Technical Information of China (English)

    马勋; 袁建强; 刘宏伟; 王凌云; 姜苹; 李洪涛

    2016-01-01

    A repetitive rate flash X-ray generator was developed recently to meet the demands in scientific research and in-dustrial area.A repetitive pulsed power supply was fabricated with GaAs photo conductive semiconductor switches and stacked Blumlein pulse forming networks to drive industrial X-ray diode,and a novel X-ray diode was proposed with spoked metal ceramic flashover cathode.The results show that 2 pulse burst X rays were generated under 1 kHz frame rate with novel cathode,and the two power pulses of diode and X-ray signals were identical.%采用砷化镓光导开关和Blumlein 型脉冲形成网络以级联的拓扑形式构建平顶输出功率源,驱动工业 X 光二极管产生 X 射线。提出了一种轮辐状金属-陶瓷沿面阴极,并与普通金属阴极工业 X 光二极管重复频率实验结果进行比较。研究表明:受限于阴极重复频率下的电流发射能力,普通金属阴极工业 X 光二极管难以实现1 kHz 重复频率,采用新型阴极二极管实现了1 kHz 重复频率2猝发脉冲 X 光输出,这两个脉冲的二极管功率、X 射线信号基本一致。

  2. Temporal synchronization of GHz repetition rate electron and laser pulses for the optimization of a compact inverse-Compton scattering x-ray source

    CERN Document Server

    Hadmack, Michael R; Madey, John M J; Kowalczyk, Jeremy M D

    2014-01-01

    The operation of an inverse-Compton scattering source of x-rays or gamma-rays requires the precision alignment and synchronization of highly focused electron bunches and laser pulses at the collision point. The arrival times of electron and laser pulses must be synchronized with picosecond precision. We have developed an RF synchronization technique that reduces the initial timing uncertainty from 350 ps to less than 2 ps, greatly reducing the parameter space to be optimized while commissioning the x-ray source. We describe the technique and present measurements of its performance.

  3. HIgh Rate X-ray Fluorescence Detector

    Energy Technology Data Exchange (ETDEWEB)

    Grudberg, Peter Matthew [XIA LLC

    2013-04-30

    The purpose of this project was to develop a compact, modular multi-channel x-ray detector with integrated electronics. This detector, based upon emerging silicon drift detector (SDD) technology, will be capable of high data rate operation superior to the current state of the art offered by high purity germanium (HPGe) detectors, without the need for liquid nitrogen. In addition, by integrating the processing electronics inside the detector housing, the detector performance will be much less affected by the typically noisy electrical environment of a synchrotron hutch, and will also be much more compact than current systems, which can include a detector involving a large LN2 dewar and multiple racks of electronics. The combined detector/processor system is designed to match or exceed the performance and features of currently available detector systems, at a lower cost and with more ease of use due to the small size of the detector. In addition, the detector system is designed to be modular, so a small system might just have one detector module, while a larger system can have many you can start with one detector module, and add more as needs grow and budget allows. The modular nature also serves to simplify repair. In large part, we were successful in achieving our goals. We did develop a very high performance, large area multi-channel SDD detector, packaged with all associated electronics, which is easy to use and requires minimal external support (a simple power supply module and a closed-loop water cooling system). However, we did fall short of some of our stated goals. We had intended to base the detector on modular, large-area detectors from Ketek GmbH in Munich, Germany; however, these were not available in a suitable time frame for this project, so we worked instead with pnDetector GmbH (also located in Munich). They were able to provide a front-end detector module with six 100 m^2 SDD detectors (two monolithic arrays of three elements each) along with

  4. Towards hard X-ray imaging at GHz frame rate

    Energy Technology Data Exchange (ETDEWEB)

    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

    2012-05-02

    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.

  5. Towards hard x-ray imaging at GHz frame rate.

    Science.gov (United States)

    Wang, Zhehui; Morris, C L; Kapustinsky, J S; Kwiatkowski, K; Luo, S-N

    2012-10-01

    Gigahertz (GHz) imaging using hard x-rays (> or approximately equal 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.

  6. Towards hard X-ray imaging at GHz frame rate

    CERN Document Server

    Wang, Zhehui; Kapustinsky, J S; Kwiatkowski, K; Luo, S -N

    2012-01-01

    Gigahertz (GHz) imaging using hard X-rays ($\\gtrsim$ 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.

  7. Towards hard x-ray imaging at GHz frame rate

    Energy Technology Data Exchange (ETDEWEB)

    Wang Zhehui; Morris, C. L.; Kapustinsky, J. S.; Kwiatkowski, K.; Luo, S.-N. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

    2012-10-15

    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.

  8. X-ray ionization rates in protoplanetary discs

    CERN Document Server

    Ercolano, B

    2013-01-01

    Low-mass young stellar objects are powerful emitters of X-rays that can ionize and heat the disks and the young planets they harbour. The X-rays produce molecular ions that affect the chemistry of the disk atmospheres and their spectroscopic signatures. Deeper down, X-rays are the main ionization source and influence the operation of the magnetorotational instability, believed to be the main driver for the angular momentum redistribution crucial for the accretion and formation of these pre main-sequence stars. X-ray ionization also affects the character of the dead zones around the disk midplane where terrestrial planets are likely to form. To obtain the physical and chemical effects of the stellar X-rays, their propagation through the disk has to be calculated taking into account both absorption and scattering. To date the only calculation of this type was done almost 15 years ago, and here we present new three-dimensional radiative transfer calculations of X-ray ionization rates in protoplanetary discs. Our...

  9. Guest–Host Interactions Investigated by Time-Resolved X-ray Spectroscopies and Scattering at MHz Rates

    DEFF Research Database (Denmark)

    Haldrup, Martin Kristoffer; Vanko, G.; Gawelda, W.

    2012-01-01

    We have studied the photoinduced low spin (LS) to high spin (HS) conversion of [Fe(bipy)3]2+ in aqueous solution. In a laser pump/X-ray probe synchrotron setup permitting simultaneous, time-resolved X-ray diffuse scattering (XDS) and X-ray spectroscopic measurements at a 3.26 MHz repetition rate...... lifetime, allowing the detection of an ultrafast change in bulk solvent density. An analysis approach directly utilizing the spectroscopic data in the XDS analysis effectively reduces the number of free parameters, and both combined permit extraction of information about the ultrafast structural dynamics...

  10. Search for Two-Photon Interaction with Axionlike Particles Using High-Repetition Pulsed Magnets and Synchrotron X Rays

    Science.gov (United States)

    Inada, T.; Yamazaki, T.; Namba, T.; Asai, S.; Kobayashi, T.; Tamasaku, K.; Tanaka, Y.; Inubushi, Y.; Sawada, K.; Yabashi, M.; Ishikawa, T.; Matsuo, A.; Kawaguchi, K.; Kindo, K.; Nojiri, H.

    2017-02-01

    We report on new results of a search for a two-photon interaction with axionlike particles (ALPs). The experiment is carried out at a synchrotron radiation facility using a "light shining through a wall (LSW)" technique. For this purpose, we develop a novel pulsed-magnet system, composed of multiple racetrack magnets and a transportable power supply. It produces fields of about 10 T over 0.8 m with a high repetition rate of 0.2 Hz and yields a new method of probing a vacuum with high intensity fields. The data obtained with a total of 27 676 pulses provide a limit on the ALP-two-photon coupling constant that is more stringent by a factor of 5.2 compared to a previous x-ray LSW limit for the ALP mass ≲0.1 eV .

  11. Search for Two-Photon Interaction with Axionlike Particles Using High-Repetition Pulsed Magnets and Synchrotron X Rays

    CERN Document Server

    Inada, T; Namba, T; Asai, S; Kobayashi, T; Tamasaku, K; Tanaka, Y; Inubushi, Y; Sawada, K; Yabashi, M; Ishikawa, T; Matsuo, A; Kawaguchi, K; Kindo, K; Nojiri, H

    2016-01-01

    We report on new results of a search for two-photon interaction with axionlike particles (ALPs). The experiment was carried out at a synchrotron radiation facility using a "light shining through a wall (LSW)" technique. For this purpose, we have developed a novel pulsed-magnet system, composed of multiple racetrack-magnets and a transportable power supply. It produces fields of about 10 T over 0.8 m with a high repetition rate of 0.2 Hz and yields a new method of probing vacuum with high intensity fields. The data obtained with a total of 27,676 pulses provide a limit on the ALP-two-photon coupling constant that is more stringent by a factor of 5.2 compared to a previous x-ray LSW limit for the ALP mass below 0.1 eV.

  12. X-ray bursts at extreme mass accretion rates from GX 17+2

    CERN Document Server

    Kuulkers, E; Van der Klis, M; Lewin, W H G; Méndez, M

    2002-01-01

    (abridged version) We report on ten X-ray bursts from GX 17+2 in RXTE data in 1996-2000. Three bursts were short in duration (~10 s), whereas the others lasted for ~6-25 min. Five of the long bursts showed evidence for radius expansion of the neutron star photosphere. No correlations of the burst properties with respect to the persistent X-ray spectral properties are seen, suggesting no correlation with inferred persistent mass accretion rate. The presence of short bursts in GX 17+2 and other bright X-ray sources, i.e. Cyg X-2, GX 3+1 and GX 13+1, as well as the ABSENCE of bursts in the bright X-ray sources Sco X-1, GX 5-1, GX 340+0, GX 349+2, GX 9+1 and GX 9+9 is not accounted for in the current X-ray bursts theories at the high mass accretion rates encountered in these sources. We find that in contrast to previous suggestions the persistent black-body emission does NOT arise from the same site as the burst emission. The black-body component of the persistent emission is consistent with arising in an expande...

  13. Pushing X-Ray Photon Correlation Spectroscopy beyond the continuous frame rate limit

    Energy Technology Data Exchange (ETDEWEB)

    Dufresne, Eric M.; Narayanan, Suresh; Sandy, Alec R.; Kline, David M.; Zhang, Qingteng; Landahl, Eric C.; Ross, Steve

    2016-01-11

    We demonstrate delayed-frame X-ray Photon Correlation Spectroscopy with 120 microsecond time resolution, limited only by sample scattering rates, with a prototype Pixel-array detector capable of taking two image frames separated by 153 ns or less. Although the overall frame rate is currently limited to about 4 frame pairs per second, we easily measured millisecond correlation functions. This technology, coupled to the use of brighter synchrotrons such as Petra III or the NSLS-II should enable X-ray Photon Correlation Spectroscopy on microsecond time scales on a wider variety of materials.

  14. Fast frame rate rodent cardiac x-ray imaging using scintillator lens coupled to CMOS camera

    Science.gov (United States)

    Swathi Lakshmi, B.; Sai Varsha, M. K. N.; Kumar, N. Ashwin; Dixit, Madhulika; Krishnamurthi, Ganapathy

    2017-03-01

    Micro-Computed Tomography (MCT) systems for small animal imaging plays a critical role for monitoring disease progression and therapy evaluation. In this work, an in-house built micro-CT system equipped with a X-ray scintillator lens coupled to a commercial CMOS camera was used to test the feasibility of its application to Digital Subtraction Angiography (DSA). Literature has reported such studies being done with clinical X-ray tubes that can be pulsed rapidly or with rotating gantry systems, thus increasing the cost and infrastructural requirements.The feasibility of DSA was evaluated by injected Iodinated contrast agent (ICA) through the tail vein of a mouse. Projection images of the heart were acquired pre and post contrast using the high frame rate X-ray detector and processing done to visualize transit of ICA through the heart.

  15. Dependence of X-Ray Burst Models on Nuclear Reaction Rates

    Science.gov (United States)

    Cyburt, R. H.; Amthor, A. M.; Heger, A.; Johnson, E.; Keek, L.; Meisel, Z.; Schatz, H.; Smith, K.

    2016-10-01

    X-ray bursts are thermonuclear flashes on the surface of accreting neutron stars, and reliable burst models are needed to interpret observations in terms of properties of the neutron star and the binary system. We investigate the dependence of X-ray burst models on uncertainties in (p, γ), (α, γ), and (α, p) nuclear reaction rates using fully self-consistent burst models that account for the feedbacks between changes in nuclear energy generation and changes in astrophysical conditions. A two-step approach first identified sensitive nuclear reaction rates in a single-zone model with ignition conditions chosen to match calculations with a state-of-the-art 1D multi-zone model based on the Kepler stellar evolution code. All relevant reaction rates on neutron-deficient isotopes up to mass 106 were individually varied by a factor of 100 up and down. Calculations of the 84 changes in reaction rate with the highest impact were then repeated in the 1D multi-zone model. We find a number of uncertain reaction rates that affect predictions of light curves and burst ashes significantly. The results provide insights into the nuclear processes that shape observables from X-ray bursts, and guidance for future nuclear physics work to reduce nuclear uncertainties in X-ray burst models.

  16. Sensitivity of Type I X-Ray Bursts to rp-Process Reaction Rates

    CERN Document Server

    Amthor, A M; Heger, A; Sakharuk, A; Schatz, H; Smith, K; Galaviz, Daniel; Heger, Alexander; Sakharuk, Alexander; Schatz, Hendrik; Smith, Karl

    2006-01-01

    First steps have been taken in a more comprehensive study of the dependence of observables in Type I X-ray bursts on uncertain (p,gamma) reaction rates along the rp-process path. We use the multizone hydrodynamics code KEPLER which implicitly couples a full nuclear reaction network of more than 1000 isotopes, as needed, to follow structure and evolution of the X-ray burst layer and its ashes. This allows us to incorporate the full rp-process network, including all relevant nuclear reactions, and individually study changes in the X-ray burst light curves when modifying selected key nuclear reaction rates. In this work we considered all possible proton captures to nuclei with 10 < Z < 28 and N <= Z. When varying individual reaction rates within a symmetric full width uncertainty of a factor of 10000, early results for some rates show changes in the burst light curve as large as 10 percent of peak luminosity. This is very large compared to the current sensitivity of X-ray observations. More precise reac...

  17. Atmospheric pressure operation of a repetitive KrF laser-plasma x-ray source at hv = 1.1 keV

    Science.gov (United States)

    Turcu, I. C. Edmond; O'Neill, Fergus; Tallents, Gregory J.; Hannon, T.; Batani, Dimitri; Giulietti, Antonio; Wharton, C. W.; Meldrum, R. A.

    1990-08-01

    A repetitively pulsed (5Hz) KrF laser-based X-ray source producing photons at i-ru 1.1 keV (copper, L-shell) from a copper coated rotating target has been used to study soft X-ray induced DNA damage effects in Chinese hamster cells. The source was computer controlled for accurate delivery to the biological material of pre-set doses. DNA damage was induced by exposures lasting 7s for V79 cells and 40s for AA8 cells. To minimise the debris from the laser-plasma source and for convenient handling of biological specimens, the target chamber contained helium at 1 atmosphere with a slow flow. The X-ray yield of the source decreased by only at most 10-20% compared to vacuum operation and a further 16% of X-rays were absorbed in helium between target and the biological material placed outside the target chamber behind a beryllium filter. The measured spectral and spatial distribution of the copper X-ray emission was found to be largely independent of the ambient helium pressure. The time resolved X-ray signal lasted for only 3 ns starting at the beginning of the 2lns laser pulse and its shape was independent of helium pressure in the target chamber.

  18. Proposal of a compact repetitive dichromatic x-ray generator with millisecond duty cycle for medical applications

    Science.gov (United States)

    Bessonov, E. G.; Gorbunkov, M. V.; Tunkin, V. G.; Fechtchenko, R. M.; Artyukov, I. A.; Shabalin, Yu. V.; Kostryukov, P. V.; Maslova, Yu. Y.; Poseryaev, A. V.; Shvedunov, V. I.; Vinogradov, A. V.; Mikhailichenko, A. A.; Ishkhanov, B. S.

    2005-12-01

    Many practical applications of x-rays lie in the important for the society fields of medical imaging, custom, transport inspection and security. Scientific applications besides of fundamental research include material sciences, biomicroscopy, and protein crystallography. Two types of x-ray sources dominate now: conventional tubes and electron accelerators equipped with insertion devices. The first are relatively cheap, robust, and compact but have low brightness and poorly controlled photon spectrum. The second generate low divergent beams with orders of magnitude higher brightness and well-controlled and tunable spectrum, but are very expensive and large in scale. So accelerator based x-ray sources are mainly still used for scientific applications and x-ray tubes - in commercial equipment. The latter motivated by the importance for the society made an impressive progress during last decades mostly due to the fast developments of radiation detectors, computers and software used for image acquisition and processing. At the same time many important problems cannot be solved without radical improvement of the parameters of the x-ray beam that in commercial devices is still provided by conventional x-ray tubes. Therefore there is a quest now for a compact and relatively cheap source to generate x-ray beam with parameters and controllability approaching synchrotron radiation. Rapid developments of lasers and particle accelerators resulted in implementation of laser plasma x-ray sources and free electron lasers for various experiments requiring high intensity, shrt duration and monochromatic x-ray radiation. Further progress towards practical application is expected from the combination of laser and particle accelerator in a single unit for efficient x-ray generation.

  19. Ultrasonic acoustic levitation for fast frame rate X-ray protein crystallography at room temperature.

    Science.gov (United States)

    Tsujino, Soichiro; Tomizaki, Takashi

    2016-05-06

    Increasing the data acquisition rate of X-ray diffraction images for macromolecular crystals at room temperature at synchrotrons has the potential to significantly accelerate both structural analysis of biomolecules and structure-based drug developments. Using lysozyme model crystals, we demonstrated the rapid acquisition of X-ray diffraction datasets by combining a high frame rate pixel array detector with ultrasonic acoustic levitation of protein crystals in liquid droplets. The rapid spinning of the crystal within a levitating droplet ensured an efficient sampling of the reciprocal space. The datasets were processed with a program suite developed for serial femtosecond crystallography (SFX). The structure, which was solved by molecular replacement, was found to be identical to the structure obtained by the conventional oscillation method for up to a 1.8-Å resolution limit. In particular, the absence of protein crystal damage resulting from the acoustic levitation was carefully established. These results represent a key step towards a fully automated sample handling and measurement pipeline, which has promising prospects for a high acquisition rate and high sample efficiency for room temperature X-ray crystallography.

  20. Ultrasonic acoustic levitation for fast frame rate X-ray protein crystallography at room temperature

    Science.gov (United States)

    Tsujino, Soichiro; Tomizaki, Takashi

    2016-05-01

    Increasing the data acquisition rate of X-ray diffraction images for macromolecular crystals at room temperature at synchrotrons has the potential to significantly accelerate both structural analysis of biomolecules and structure-based drug developments. Using lysozyme model crystals, we demonstrated the rapid acquisition of X-ray diffraction datasets by combining a high frame rate pixel array detector with ultrasonic acoustic levitation of protein crystals in liquid droplets. The rapid spinning of the crystal within a levitating droplet ensured an efficient sampling of the reciprocal space. The datasets were processed with a program suite developed for serial femtosecond crystallography (SFX). The structure, which was solved by molecular replacement, was found to be identical to the structure obtained by the conventional oscillation method for up to a 1.8-Å resolution limit. In particular, the absence of protein crystal damage resulting from the acoustic levitation was carefully established. These results represent a key step towards a fully automated sample handling and measurement pipeline, which has promising prospects for a high acquisition rate and high sample efficiency for room temperature X-ray crystallography.

  1. Plan for PLEX X-Ray Ablation Experiments and Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Latkowski, J F; Reyes, S

    2001-09-27

    PLEX is a Z-pinch based x-ray source that can produce x-rays with fluences (0.3-18 J/cm{sup 2}), pulselengths (10-30 ns), repetition rates (<10 Hz), and energies (50-500 eV) of interest for IFE chambers and optics. It provides an affordable, dedicated method to advance our understanding of x-ray damage to materials. The PLEX x-ray source will be used to experimentally validate and further develop the ABLATOR x-ray ablation code for use in inertial fusion energy (IFE) studies.

  2. Stellar Masses, Star Formation Rates and X-ray Constraints on Galaxies in the Coma Cluster

    Science.gov (United States)

    Hrinda, Greg; Desjardins, T. D.; Hornschemeier, A. E.; Gallagher, S.; Hammer, D.; Miller, N. A.; Ptak, A.; Tzanavaris, P.; Johnson, K. E.; Walker, L.

    2014-01-01

    We report on new measurements of star formation rates and stellar masses in the “infall” region of the nearby Coma cluster of galaxies. This region is approximately 1 Mpc from the cluster core, where relatively gas-rich galaxies are interacting with the hot intracluster medium, providing an important view of the impact of cluster processes on galaxy evolution. We have used infrared and ultraviolet data available from both ground and spaced-based observations to make these measurements. The star formation rates and stellar mass values were verified via comparison with published results in the Coma core as well as the Sloan Digital Sky Survey spectral measurements. The infall region has also been observed by XMM-Newton to faint limits to obtain X-ray luminosities for the galaxies in this field. Specifically, we present X-ray photometry of approximately 20 galaxies with XMM-Newton coverage to constrain the X-ray - SFR correlation in a cluster environment. This project was supported by the Baltimore Excellence in STEM Teaching program via summer internship funding to Hrinda.

  3. Determination of the deposition rate of DC magnetron sputtering in fabrication of X-ray supermirrors

    Institute of Scientific and Technical Information of China (English)

    Fengli Wang; Zhanshan Wang; Jingtao Zhu; Zhong Zhang; Wenjuan Wu; Shumin Zhang; Lingyan Chen

    2006-01-01

    @@ X-ray supermirror is a non-periodic multilayer structure,whose optical performance is greatly affected by the stability and accuracy of the deposition rate in the fabrication using the direct current (DC) magnetron sputtering.By considering the location-setting time of the substrate positioning above the sputtering target,the deposition rate can be accurately determined.Experimental results show that the optical performance of the supermirror is in agreement with the design aim,which indicates that the layer thickness is well controlled and coincides with the desired ones.

  4. Low-noise multichannel ASIC for high count rate X-ray diffractometry applications

    Energy Technology Data Exchange (ETDEWEB)

    Szczygiel, R. [AGH University of Science and Technology, Department of Measurement and Instrumentation, al. Mickiewicza 30, Krakow (Poland)], E-mail: robert.szczygiel@agh.edu.pl; Grybos, P.; Maj, P. [AGH University of Science and Technology, Department of Measurement and Instrumentation, al. Mickiewicza 30, Krakow (Poland); Tsukiyama, A.; Matsushita, K.; Taguchi, T. [Rigaku Corporation, 3-9-12 Matsubara-cho, Akishima-shi, Tokyo (Japan)

    2009-08-01

    RG64 is a 64-channel ASIC designed for the silicon strip detector readout and optimized for high count rate X-ray imaging applications. In this paper we report on the test results referring to the RG64 noise level, channel uniformity and the operation with a high rate of input signals. The parameters of the RG64-based diffractometry system are compared with the ones based on the scintillation counter. Diffractometry measurement results with silicon strip detectors of different strip lengths and strip pitch are also presented.

  5. The deepest X-ray view of high-redshift galaxies: constraints on low-rate black-hole accretion

    CERN Document Server

    Vito, Fabio; Vignali, Cristian; Brandt, William N; Comastri, Andrea; Yang, Guang; Lehmer, Bret D; Luo, Bin; Basu-Zych, Antara; Bauer, Franz E; Cappelluti, Nico; Koekemoer, Anton; Mainieri, Vincenzo; Paolillo, Maurizio; Ranalli, Piero; Shemmer, Ohad; Trump, Jonathan; Wang, Junxian; Xue, Yongquan

    2016-01-01

    We exploit the 7 Ms \\textit{Chandra} observations in the \\chandra\\,Deep Field-South (\\mbox{CDF-S}), the deepest X-ray survey to date, coupled with CANDELS/GOODS-S data, to measure the total X-ray emission arising from 2076 galaxies at $3.5\\leq z 3.7\\sigma$) X-ray emission from massive galaxies at $z\\approx4$. We also report the detection of massive galaxies at $z\\approx5$ at a $99.7\\%$ confidence level ($2.7\\sigma$), the highest significance ever obtained for X-ray emission from galaxies at such high redshifts. No significant signal is detected from galaxies at even higher redshifts. The stacking results place constraints on the BHAD associated with the known high-redshift galaxy samples, as well as on the SFRD at high redshift, assuming a range of prescriptions for X-ray emission due to X- ray binaries. We find that the X-ray emission from our sample is likely dominated by processes related to star formation. Our results show that low-rate mass accretion onto SMBHs in individually X-ray-undetected galaxies i...

  6. X-Ray Supernovae

    CERN Document Server

    Immler, S; Immler, Stefan; Lewin, Walter H.G.

    2002-01-01

    We present a review of X-ray observations of supernovae (SNe). By observing the (~0.1--100 keV) X-ray emission from young SNe, physical key parameters such as the circumstellar matter (CSM) density, mass-loss rate of the progenitor and temperature of the outgoing and reverse shock can be derived as a function of time. Despite intensive search over the last ~25 years, only 15 SNe have been detected in X-rays. We review the individual X-ray observations of these SNe and discuss their implications as to our understanding of the physical processes giving rise to the X-ray emission.

  7. An automatic attenuator device for x-ray detectors at high counting rate

    Science.gov (United States)

    Alvarez, J.; Paiser, E.; Capitan, M. J.

    2002-07-01

    In this article we describe an attenuator device for reducing/controlling the pulse detector counting losses at a high counting rate. The electronics are based on a direct measure of the detector dead time from the analog output signal at the end of the detection chain. Taking into account this parameter the attenuator device decides to reduce/enhance the number of photons that arrive at the detector by inserting/extracting the necessary number of attenuation foils in the x-ray beam path. In that way the number of events in the incoming signal are reduced and the "apparent dynamic range" of the detector is increased.

  8. Dependence of X-Ray Burst Models on Nuclear Reaction Rates

    CERN Document Server

    Cyburt, R H; Heger, A; Johnson, E; Keek, L; Meisel, Z; Schatz, H; Smith, K

    2016-01-01

    X-ray bursts are thermonuclear flashes on the surface of accreting neutron stars and reliable burst models are needed to interpret observations in terms of properties of the neutron star and the binary system. We investigate the dependence of X-ray burst models on uncertainties in (p,$\\gamma$), ($\\alpha$,$\\gamma$), and ($\\alpha$,p) nuclear reaction rates using fully self-consistent burst models that account for the feedbacks between changes in nuclear energy generation and changes in astrophysical conditions. A two-step approach first identified sensitive nuclear reaction rates in a single-zone model with ignition conditions chosen to match calculations with a state-of-the-art 1D multi-zone model based on the {\\Kepler} stellar evolution code. All relevant reaction rates on neutron deficient isotopes up to mass 106 were individually varied by a factor of 100 up and down. Calculations of the 84 highest impact reaction rate changes were then repeated in the 1D multi-zone model. We find a number of uncertain reac...

  9. Survey on th incidence of homeless pulmonary tuberculosis infection rate through chest x-ray examination

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Mi Young; Shin, Sung Rae [Dept. of Nursing, Sahmyook University, Seoul (Korea, Republic of); Ryu, Young Hwan [Dept. of Radiology, Seoul Medical Center, Seoul (Korea, Republic of); Lim, Hwan Yeal [Dept. of Medical Business Administration, U1 University, Yeongdong (Korea, Republic of)

    2017-02-15

    This study, Seoul City shelter, you are trying to seek medical cooperation and cure rate increase proposal Yu fndings’s current situation and tuberculosis of homeless tuberculosis. Inspector, and has a total 591 people is targeted to implement an interview after acquiring utilization agreement in studies conducted chest X-ray photography. Of the interview questions, three or more protons, it is determined that the TB symptomatic conducted sputum examination, chest X-ray examination confrms the physician radiology, when sputum examination primarily chromatic fndings the double implemented and conducted by requesting the ship inspection also said inspection sputum acid-fast bacteria if it is true one, respectively. confrmed case result of checking whether there is a difference due to risk factors (Jb) at the chi square black, it was found that there is no statistically significant difference at 95% confidence level. (χ{sup 2}=0.276, p>0.05), suspected case (Ac, Ae) results of examining whether there is a difference due to risk factors in chi square black, that there is a statistically significant difference at 99% confidence level is I found (χ{sup 2}=9.414, p<0.01). The nature of the homeless tuberculosis screening and directed to the distance homeless specifc location are likely to evaluate the actual incidence low and aggressive or management needs, the rationale is allowed insufficient reality is. Through this research, future, for tuberculosis high risk tuberculosis patient, such as homeless to expand the tuberculosis screening of infectious tuberculosis patients in private medical institutions, and one-stop service that chest X-ray examination and sputum examination is carried out at the same time introduced immediately to prevent the inspection and examination, cure, and should establish a foundation that can be up to post administration.

  10. Alternative Optimizations of X-ray TES Arrays: Soft X-rays, High Count Rates, and Mixed-Pixel Arrays

    Science.gov (United States)

    Kilbourne, C. A.; Bandler, S. R.; Brown, A.-D.; Chervenak, J. A.; Figueroa-Feliciano, E.; Finkbeiner, F. M.; Iyomoto, N.; Kelley, R. L.; Porter, F. S.; Smith, S. J.

    2007-01-01

    We are developing arrays of superconducting transition-edge sensors (TES) for imaging spectroscopy telescopes such as the XMS on Constellation-X. While our primary focus has been on arrays that meet the XMS requirements (of which, foremost, is an energy resolution of 2.5 eV at 6 keV and a bandpass from approx. 0.3 keV to 12 keV), we have also investigated other optimizations that might be used to extend the XMS capabilities. In one of these optimizations, improved resolution below 1 keV is achieved by reducing the heat capacity. Such pixels can be based on our XMS-style TES's with the separate absorbers omitted. These pixels can added to an array with broadband response either as a separate array or interspersed, depending on other factors that include telescope design and science requirements. In one version of this approach, we have designed and fabricated a composite array of low-energy and broad-band pixels to provide high spectral resolving power over a broader energy bandpass than could be obtained with a single TES design. The array consists of alternating pixels with and without overhanging absorbers. To explore optimizations for higher count rates, we are also optimizing the design and operating temperature of pixels that are coupled to a solid substrate. We will present the performance of these variations and discuss other optimizations that could be used to enhance the XMS or enable other astrophysics experiments.

  11. Rate equations for nitrogen molecules in ultrashort and intense x-ray pulses

    CERN Document Server

    Liu, Ji-Cai; Cederbaum, Lorenz S; Cryan, James P; Glownia, James M; Schafer, Kenneth J; Buth, Christian

    2015-01-01

    We study theoretically the molecular dynamics of nitrogen molecules (N$_2$) exposed to x rays at a wavelength of 1.1 nm (1100 eV photon energy) from the Linac Coherent Light Source (LCLS) free electron laser. Molecular rate equations are derived to describe the intertwined photoionization, decay, and dissociation processes occurring for N2 in intense and ultrafast x rays from LCLS. This model complements our earlier phenomenological approaches, the single-atom, symmetric-sharing, and fragmentation-matrix models of J. Chem. Phys. $\\mathbf{136}$, 214310 (2012). Our rate-equations are used to obtain the effective pulse energy at the sample and the time scale for the dissociation of the metastable dication N$_2^{2+}$. This leads to a very good agreement between the theoretically and experimentally obtained ion yields and, consequently, the average charge states. The effective pulse energy is found to decrease with shortening pulse duration. This variation in the effective pulse energy together with a change in th...

  12. DETERMINATION OF HLW GLASS MELT RATE USING X-RAY COMPUTED TOMOGRAPHY

    Energy Technology Data Exchange (ETDEWEB)

    Choi, A.; Miller, D.; Immel, D.

    2011-10-06

    , a significant amount of glassy material interspersed among the gas bubbles will be excluded, thus underestimating the melt rate. Likewise, if they are drawn too high, many large voids will be counted as glass, thus overestimating the melt rate. As will be shown later in this report, there is also no guarantee that a given distribution of glass and gas bubbles along a particular sectioned plane will always be representative of the entire sample volume. Poor reproducibility seen in some LMR data may be related to these difficulties of the visual method. In addition, further improvement of the existing melt rate model requires that the overall impact of feed chemistry on melt rate be reflected on measured data at a greater quantitative resolution on a more consistent basis than the visual method can provide. An alternate method being pursued is X-ray computed tomography (CT). It involves X-ray scanning of glass samples, performing CT on the 2-D X-ray images to build 3-D volumetric data, and adaptive segmentation analysis of CT results to not only identify but quantify the distinct regions within each sample based on material density and morphologies. The main advantage of this new method is that it can determine the relative local density of the material remaining in the beaker after the heat treatment regardless of its morphological conditions by selectively excluding all the voids greater than a given volumetric pixel (voxel) size, thus eliminating much of the subjectivity involved in the visual method. As a result, the melt rate data obtained from CT scan will give quantitative descriptions not only on the fully-melted glass, but partially-melted and unmelted feed materials. Therefore, the CT data are presumed to be more reflective of the actual melt rate trends in continuously-fed melters than the visual data. In order to test the applicability of X-ray CT scan to the HLW glass melt rate study, several new series of HLW simulant/frit mixtures were melted in the

  13. X-ray generation by the interaction of laser pulses of GW and high repetition rate, with solid targets of Al, Cu, Cd and Au; Generacion de rayos X por interaccion de pulsos laser de GW y alta tasa de repeticion, con blancos solidos de Al, Cu, Cd, Au

    Energy Technology Data Exchange (ETDEWEB)

    Fonseca Cuenca, C.; Rodriguez Entem, D.; Mendez Valverde, C.; Roso Franco, L.; Fernandez Gonzalez, F.

    2011-07-01

    In the present study we characterized the Bremsstrahlung radiation and X-ray emission associated with the radiation emitted during the interaction of laser pulses incident on solid targets of different material and discusses the radiation risk generated by the nature of this interaction.

  14. Low-Mass X-Ray Binaries, Millisecond Radio Pulsars, and the Cosmic Star Formation Rate

    CERN Document Server

    White, N E; White, Nicholas E.; Ghosh, Pranab

    1998-01-01

    We report on the implications of the peak in the cosmic star-formation rate (SFR) at redshift z ~ 1.5 for the resulting population of low-mass X-ray binaries(LMXB) and for that of their descendants, the millisecond radio pulsars (MRP). Since the evolutionary timescales of LMXBs, their progenitors, and their descendants are thought be significant fractions of the time-interval between the SFR peak and the present epoch, there is a lag in the turn-on of the LMXB population, with the peak activity occurring at z ~ 0.5 - 1.0. The peak in the MRP population is delayed further, occurring at z < 0.5. We show that the discrepancy between the birthrate of LMXBs and MRPs, found under the assumption of a stead-state SFR, can be resolved for the population as a whole when the effects of a time-variable SFR are included. A discrepancy may persist for LMXBs with short orbital periods, although a detailed population synthesis will be required to confirm this. Further, since the integrated X-ray luminosity distribution of...

  15. The Binary Black Hole Merger Rate from Ultraluminous X-ray Source Progenitors

    Science.gov (United States)

    Finke, Justin; Razzaque, Soebur

    2017-01-01

    Ultraluminous X-ray sources (ULXs) exceed the Eddington luminosity for an approximately 10 solar mass black hole. The recent detection of a black hole merger event GW 150914 by the gravitational wave detector ALIGO indicates that black holes with mass greater than 10 do indeed exist. Motivated by this, we explore a scenario where ULXs consist of black holes formed by the collapse of high-mass, low-metallicity stars, and that these ULXs become binary black holes (BBHs) that eventually merge. We use empirical relations between the number of ULXs and the star formation rate and host galaxy metallicity to estimate the ULX formation rate and the BBH merger rate at all redshifts. This assumes the ULX rate is directly proportional to the star formation rate for a given metallicity, and that the black hole accretion rate is distributed as a log-normal distribution. We include an enhancement in the ULX formation rate at earlier epochs due to lower mean metallicities. Our model is able to reproduce both the rate and mass distribution of BBH mergers in the nearby universe inferred from the detection of GW 150914, LVT 151012, and GW 151226 by LIGO if the median accretion rate of ULXs is a factor 1 to 30 greater than the Eddington rate. Our predictions of the BBH merger rate, mass distribution.

  16. High resolution Si(Li) X-ray spectrometer with high throughput rate

    Energy Technology Data Exchange (ETDEWEB)

    Bacso, J.; Kalinka, G.; Kertesz, Zs.; Kovacs, P.; Lakatos, T. (Magyar Tudomanyos Akademia Atommag Kutato Intezete, Debrecen)

    1982-06-01

    The paper presents the description of a modern Si(Li) X-ray spectrometer developed in ATOMKI. The Si(Li) detectors are single-grooved with an active area of 20-50 mm/sup 2/. The Be window is coated with a special protective layer against corrosion. A small getter-ion pump maintains the high vacuum in the cryostat chamber. The preamplifier employs pulsed drain feedback; in its first stage selected, teflon-encapsulated field effect transistors are used. The analogue signal processor is direct coupled and employs time variant pulse shaping. This construction provides high resolution (150-170 eV), high throughput rate, excellent stability, effective pile-up elimination, accurate live-time correction and simplicity in the applications. The live-time correction is performed by a random pulse generator, its average frequency is stabilized and the corresponding peak appears at zero energy in the spectra.

  17. DETERMINATION OF HLW GLASS MELT RATE USING X-RAY COMPUTED TOMOGRAPHY

    Energy Technology Data Exchange (ETDEWEB)

    Choi, A.; Miller, D.; Immel, D.

    2011-10-06

    , a significant amount of glassy material interspersed among the gas bubbles will be excluded, thus underestimating the melt rate. Likewise, if they are drawn too high, many large voids will be counted as glass, thus overestimating the melt rate. As will be shown later in this report, there is also no guarantee that a given distribution of glass and gas bubbles along a particular sectioned plane will always be representative of the entire sample volume. Poor reproducibility seen in some LMR data may be related to these difficulties of the visual method. In addition, further improvement of the existing melt rate model requires that the overall impact of feed chemistry on melt rate be reflected on measured data at a greater quantitative resolution on a more consistent basis than the visual method can provide. An alternate method being pursued is X-ray computed tomography (CT). It involves X-ray scanning of glass samples, performing CT on the 2-D X-ray images to build 3-D volumetric data, and adaptive segmentation analysis of CT results to not only identify but quantify the distinct regions within each sample based on material density and morphologies. The main advantage of this new method is that it can determine the relative local density of the material remaining in the beaker after the heat treatment regardless of its morphological conditions by selectively excluding all the voids greater than a given volumetric pixel (voxel) size, thus eliminating much of the subjectivity involved in the visual method. As a result, the melt rate data obtained from CT scan will give quantitative descriptions not only on the fully-melted glass, but partially-melted and unmelted feed materials. Therefore, the CT data are presumed to be more reflective of the actual melt rate trends in continuously-fed melters than the visual data. In order to test the applicability of X-ray CT scan to the HLW glass melt rate study, several new series of HLW simulant/frit mixtures were melted in the

  18. Design of a low emittance and high repetition rate S-band photoinjector

    Science.gov (United States)

    Han, Jang-Hui

    2014-09-01

    As an electron beam injector of X-ray free-electron lasers (FELs), photoinjectors have been developed for the past few decades. Such an injector starting with a photocathode RF gun provides high brightness beams and therefore it is being adopted as an injector of X-ray FELs. In this paper we show how to improve photoinjector performance in terms of emittance and repetition rates by means of injector components optimization, especially with the gun. Transverse emittance at the end of an injector is reduced by optimizing the gun design, gun solenoid position, and accelerating section position. The repetition rate of an injector mainly depends on the gun. It is discussed that a repetition rate of 1 kHz at a normal-conducting S-band photoinjector is feasible by adopting a coaxial RF coupler and improving cooling-water channels surrounding the gun.

  19. Dependence of the orbital modulation of X-rays from 4U 1820-303 on the accretion rate

    CERN Document Server

    Zdziarski, A A; Wen, L

    2007-01-01

    We report the discovery, using XTE data, of a dependence of the X-ray orbital modulation depth on the X-ray spectral state in the ultracompact atoll binary 4U 1820-303. This state (measured by us by the position on the X-ray colour-colour diagram) is tightly coupled to the accretion rate, which, in turn, is coupled to the phase of the 170-d superorbital cycle of this source. The modulation depth is much stronger in the high-luminosity, so-called banana, state than in the low-luminosity, island, state. We find the X-ray modulation is independent of energy, which rules out bound-free X-ray absorption in an optically thin medium as the cause of the modulation. We also find a significant dependence of the offset phase of the orbital modulation on the spectral state, which favours the model in which the modulation is caused by scattering in hot gas around a bulge at the disc edge, which both size and the position vary with the accretion rate. Estimates of the source inclination appear to rule out a model in which ...

  20. X-ray stacking of Lyman break galaxies in the 4\\,Ms CDF-S - X-ray luminosities and star formation rates across cosmic time

    CERN Document Server

    Zinn, Peter-Christian; Seymour, Nicholas; Bomans, Dominik J

    2012-01-01

    Lyman Break Galaxies (LBGs) are widely thought to be prototypical young galaxies in the early universe, particularly representative of those undergoing massive events of star formation. Therefore, LBGs should produce significant amounts of X-ray emission. We aim to trace the X-ray luminosity of Lyman Break Galaxies across cosmic time and from that derive constraints on their star formation history. We utilize the newly released 4 Ms mosaic obtained with the Chandra X-ray Observatory, the deepest X-ray image to date, alongside with the superb spectroscopic data sets available in the CDF-S survey region to construct large but nearly uncontaminated samples of LBGs across a wide range of redshift (0.5 < z < 4.5) which can be used as input samples for stacking experiments. This approach allows us to trace the X-ray emission of Lyman Break Galaxies to even lower, previously unreachable, flux density limits (~10^-18 mW m^-2) and therefore to larger redshifts. We reliably detect soft-band X-ray emission from al...

  1. Photon-counting X-ray imaging at kilohertz frame rates

    CERN Document Server

    Ponchut, Cyril; Rigal, J M; Papillon, E; Vallerga, J; LaMarra, D; Mikulec, B

    2007-01-01

    A kilohertz frame rate readout system for Medipix2 chips is being developed at European Synchrotron Radiation Facility (ESRF). This work was initiated with the aim of meeting the growing demand for fast and noise-free X-ray bidimensional detection particularly on synchrotron beamlines. Medipix2 is a photon-counting readout ASIC of 256×256 pixels with 55 μm pitch developed in the framework of the Medipix collaboration managed by CERN. The ESRF readout system is based on a custom interface board named Parallel Readout Image Acquisition for Medipix (PRIAM) a fast PCI interface and a Linux PC. The PRIAM board implementing fast FIFOs and a programmable gate array can read up to five Medipix2 circuits simultaneously in less than 0.3 ms using the 32-bit parallel readout port of Medipix2 and 100 MHz clock frequency. This paper describes the architecture of the PRIAM board, reports on the first test results, and mentions some of the targeted applications.

  2. Exploration of Spin-down Rate of Neutron Star in High Mass X-ray Binaries

    CERN Document Server

    Dai, Hai-Lang; Li, Xiang-Dong

    2016-01-01

    We use the evolutionary population synthesis method to investigate the statistical properties of the wind-fed neutron star (NS) compact ($P_{\\rm orb}<10$ days) high-mass X-ray binaries (HMXBs) in our Galaxy, based on different spin-down models. We find that the spin-down rate in the supersonic propeller phase given \\textbf{by assuming that the surrounding material is treated as forming a quasi-static atmosphere} or \\textbf{by assuming that the characteristic velocity of matter and the typical Alfv$\\acute{e}$n velocity of material in the magnetospheric boundary layer are comparable to the sound speed in the external medium} is too low to produce the observed number of compact HMXBs. We also find that the models suggested \\textbf{by assuming that the infalling material is ejected with the corotation velocity at the magnetospheric radius when the magnetospheric radius is larger than the corotation radius} and \\textbf{by simple integration of the magnetic torque over the magnetosphere} with a larger spin-down ...

  3. Explaining variation in GP referral rates for x-rays for back pain

    Directory of Open Access Journals (Sweden)

    Bond Senga

    2006-08-01

    Full Text Available Abstract Background Despite the availability of clinical guidelines for the management of low back pain (LBP, there continues to be wide variation in general practitioners' (GPs' referral rates for lumbar spine x-ray (LSX. This study aims to explain variation in GPs' referral rates for LSX from their accounts of the management of patients with low back pain. Methods Qualitative, semi-structured interviews with 29 GPs with high and low referral rates for LSX in North East England. Thematic analysis used constant comparative techniques. Results Common and divergent themes were identified among high- and low-users of LSX. Themes that were similar in both groups included an awareness of current guidelines for the use of LSX for patients with LBP and the pressure from patients and institutional factors to order a LSX. Differentiating themes for the high-user group included: a belief that LSX provides reassurance to patients that can outweigh risks, pessimism about the management options for LBP, and a belief that denying LSX would adversely affect doctor-patient relationships. Two specific differentiating themes are considered in more depth: GPs' awareness of their use of lumbar spine radiology relative to others, and the perceived risks associated with LSX radiation. Conclusion Several key factors differentiate the accounts of GPs who have high and low rates of referral for LSX, even though they are aware of clinical guideline recommendations. Intervention studies that aim to increase adherence to guideline recommendations on the use of LSX by changing the ordering behaviour of practitioners in primary care should focus on these factors.

  4. The History of Cosmic Baryons X-ray Emission vs. Star Formation Rate

    CERN Document Server

    Menci, N

    1999-01-01

    We relate the star formation from cold baryons in virialized structures to the X-ray properties of the associated diffuse, hot baryonic component. Our computations use the standard ``semi-analytic'' models to describe i) the evolution of dark matter halos through merging after the hierarchical clustering, ii) the star formation governed by radiative cooling and by supernova feedback, iii) the hydro- and thermodynamics of the hot gas, rendered with our Punctuated Equilibria model. So we relate the X-ray observables concerning the intra-cluster medium to the thermal energy of the gas pre-heated and expelled by supernovae following star formation, and then accreted during the subsequent merging events. We show that at fluxes fainter than $F_X\\approx 10^{-15}$ erg/cm$^2 $ s (well within the reach of next generation X-ray observatories) the X-ray counts of extended extragalactic sources (as well as the faint end of the luminosity function, the contribution to the soft X-ray background, and the $L_X-T$ correlation ...

  5. Count rates and structure factors in anomalous soft x-ray scattering from cuprate superconductors

    NARCIS (Netherlands)

    Abbamonte, P; Rusydi, A; Logvenov, G; Bozovic, [No Value; Sawatzky, GA; Venema, L.C.; Bozovic,; Pavuna, D

    2002-01-01

    It has recently been shown that x-ray diffraction from the doped holes in cuprates can be enhanced by 3-4 orders of magnitude by exploiting resonance effects in the oxygen K shell. This new type of anomalous scattering is direct way of probing ground state inhomogeneity in the mobile carrier liquid

  6. Measuring the shock-heating rate in the winds of O stars using X-ray line spectra

    CERN Document Server

    Cohen, David H; Gayley, Kenneth G; Owocki, Stanley P; Sundqvist, Jon O; Petit, Veronique; Leutenegger, Maurice A

    2014-01-01

    We present a new method for using measured X-ray emission line fluxes from O stars to determine the shock-heating rate due to instabilities in their radiation-driven winds. The high densities of these winds means that their embedded shocks quickly cool by local radiative emission, while cooling by expansion should be negligible. Ignoring for simplicity any non-radiative mixing or conductive cooling, the method presented here exploits the idea that the cooling post-shock plasma systematically passes through the temperature characteristic of distinct emission lines in the X-ray spectrum. In this way, the observed flux distribution among these X-ray lines can be used to construct the cumulative probability distribution of shock strengths that a typical wind parcel encounters as it advects through the wind. We apply this new method (Gayley 2014) to Chandra grating spectra from five O stars with X-ray emission indicative of embedded wind shocks in effectively single massive stars. Correcting for wind absorption of...

  7. Guiding synchrotron X-ray diffraction by multimodal video-rate protein crystal imaging

    OpenAIRE

    Newman, Justin A.; ZHANG, Shijie; Sullivan, Shane Z.; Dow, Ximeng Y.; Becker, Michael; Sheedlo, Michael J.; Stepanov, Sergey; Carlsen, Mark S.; Everly, R. Michael; Das, Chittaranjan; Fischetti, Robert F.; Simpson, Garth J.

    2016-01-01

    Synchronous digitization, in which an optical sensor is probed synchronously with the firing of an ultrafast laser, was integrated into an optical imaging station for macromolecular crystal positioning prior to synchrotron X-ray diffraction. Using the synchronous digitization instrument, second-harmonic generation, two-photon-excited fluorescence, one-photon-excited fluorescence, two-photon-excited ultraviolet fluorescence and bright field by laser transmittance were all acquired with perfect...

  8. BEAM DYNAMICS STUDIES OF A HIGH-REPETITION RATE LINAC-DRIVER FOR A 4TH GENERATION LIGHT SOURCE

    Energy Technology Data Exchange (ETDEWEB)

    Ventturini, M.; Corlett, J.; Emma, P.; Papadopoulos, C.; Penn, G.; Placidi, M.; Qiang, J.; Reinsch, M.; Sannibale, F.; Steier, C.; Sun, C.; Wells, R.

    2012-05-18

    We present recent progress toward the design of a super-conducting linac driver for a high-repetition rate FEL-based soft x-ray light source. The machine is designed to accept beams generated by the APEX photo-cathode gun operating with MHz-range repetition rate and deliver them to an array of SASE and seeded FEL beamlines. We review the current baseline design and report results of beam dynamics studies.

  9. X-Ray Background at High Redshifts from Pop III Remnants: Results from Pop III Star Formation Rates in the Renaissance Simulations

    Science.gov (United States)

    Xu, Hao; Ahn, Kyungjin; Norman, Michael L.; Wise, John H.; O'Shea, Brian W.

    2016-11-01

    Due to their long mean free paths, X-rays are expected to have global impacts on the properties of the intergalactic medium (IGM) by their large-scale heating and ionizing processes. At high redshifts, X-rays from Population (Pop) III binaries might have important effects on cosmic reionization and the Lyα forest. As a continuation of our previous work on Pop III binary X-rays, we use the Pop III distribution and evolution from the Renaissance Simulations, a suite of self-consistent cosmological radiation hydrodynamics simulations of the formation of the first galaxies, to calculate the X-ray luminosity density and background over the redshift range 20≥slant z≥slant 7.6. As we find that Pop III star formation continues at a low, nearly constant rate to the end of reionization, X-rays are being continuously produced at significant rates compared to other possible X-ray sources, such as AGNs and normal X-ray binaries during the same period of time. We estimate that Pop III binaries produce approximately 6 eV of energy in the X-rays per hydrogen atom. We calculate the X-ray background for different monochromatic photon energies. KeV X-rays redshift and accumulate to produce a strong X-ray background spectrum extending to roughly 500 eV. The X-ray background is strong enough to heat the IGM to ˜1000 K and to ionize a few percent of the neutral hydrogen. These effects are important for an understanding of the neutral hydrogen hyperfine transition 21 cm line signatures, the Lyα forest, and the Thomson optical depth to the CMB.

  10. Relativistic ejecta from X-ray flash XRF 060218 and the rate of cosmic explosions.

    Science.gov (United States)

    Soderberg, A M; Kulkarni, S R; Nakar, E; Berger, E; Cameron, P B; Fox, D B; Frail, D; Gal-Yam, A; Sari, R; Cenko, S B; Kasliwal, M; Chevalier, R A; Piran, T; Price, P A; Schmidt, B P; Pooley, G; Moon, D-S; Penprase, B E; Ofek, E; Rau, A; Gehrels, N; Nousek, J A; Burrows, D N; Persson, S E; McCarthy, P J

    2006-08-31

    Over the past decade, long-duration gamma-ray bursts (GRBs)--including the subclass of X-ray flashes (XRFs)--have been revealed to be a rare variety of type Ibc supernova. Although all these events result from the death of massive stars, the electromagnetic luminosities of GRBs and XRFs exceed those of ordinary type Ibc supernovae by many orders of magnitude. The essential physical process that causes a dying star to produce a GRB or XRF, and not just a supernova, is still unknown. Here we report radio and X-ray observations of XRF 060218 (associated with supernova SN 2006aj), the second-nearest GRB identified until now. We show that this event is a hundred times less energetic but ten times more common than cosmological GRBs. Moreover, it is distinguished from ordinary type Ibc supernovae by the presence of 10(48) erg coupled to mildly relativistic ejecta, along with a central engine (an accretion-fed, rapidly rotating compact source) that produces X-rays for weeks after the explosion. This suggests that the production of relativistic ejecta is the key physical distinction between GRBs or XRFs and ordinary supernovae, while the nature of the central engine (black hole or magnetar) may distinguish typical bursts from low-luminosity, spherical events like XRF 060218.

  11. Ultrafast structural dynamics studied by kilohertz time-resolved x-ray diffraction

    Institute of Scientific and Technical Information of China (English)

    郭鑫; 江舟亚; 陈龙; 陈黎明; 辛建国; 陈洁

    2015-01-01

    Ultrashort multi-keV x-ray pulses are generated by electron plasma produced by the irradiation of femtosecond pulses on metals. These sub-picosecond x-ray pulses have extended the field of x-ray spectroscopy into the femtosecond time domain. However, pulse-to-pulse instability and long data acquisition time restrict the application of ultrashort x-ray systems operating at low repetition rates. Here we report on the performance of a femtosecond laser plasma-induced hard x-ray source that operates at 1-kHz repetition rate, and provides a flux of 2.0 × 1010 photons/s of Cu Kα radiation. Using this system for time-resolved x-ray diffraction experiments, we record in real time, the transient processes and structural changes induced by the interaction of 400-nm femtosecond pulse with the surface of a 200-nm thick Au (111) single crystal.

  12. X-Ray Detector Simulations - Oral Presentation

    Energy Technology Data Exchange (ETDEWEB)

    Tina, Adrienne [SLAC National Accelerator Lab., Menlo Park, CA (United States)

    2015-08-20

    The free-electron laser at LCLS produces X-Rays that are used in several facilities. This light source is so bright and quick that we are capable of producing movies of objects like proteins. But making these movies would not be possible without a device that can detect the X-Rays and produce images. We need X-Ray cameras. The challenges LCLS faces include the X-Rays’ high repetition rate of 120 Hz, short pulses that can reach 200 femto-seconds, and extreme peak brightness. We need detectors that are compatible with this light source, but before they can be used in the facilities, they must first be characterized. My project was to do just that, by making a computer simulation program. My presentation discusses the individual detectors I simulated, the details of my program, and how my project will help determine which detector is most useful for a specific experiment.

  13. He flow rate measurements on the engineering model for the Astro-H Soft X-ray Spectrometer dewar

    Science.gov (United States)

    Mitsuishi, I.; Ezoe, Y.; Ishikawa, K.; Ohashi, T.; Fujimoto, R.; Mitsuda, K.; Tsunematsu, S.; Yoshida, S.; Kanao, K.; Murakami, M.; DiPirro, M.; Shirron, P.

    2014-11-01

    The sixth X-ray Japanese astronomy satellite, namely Astro-H, will be launched in 2015. The Soft X-ray Spectrometer onboard the Astro-H is a 6 × 6 X-ray microcalorimeter array and provides us with both a high energy resolution of cryocoolers, a 30-L superfluid helium cryostat, and a 3-stage adiabatic demagnetization refrigerator are utilized. A very small heat load up to ∼0.9 mW on the helium tank is allowable to realize the helium lifetime of >3 years, which consequently requires that the vapor flow rate out of the helium tank should be very small helium under zero gravity and safely vent the small amount of the helium vapor. We measured helium mass flow rates from the helium tank equipped in the engineering model dewar. We tilted the dewar at an angle of 75° so that one side of the porous plug located at the top of the helium tank attaches the liquid helium and the porous plug separates the liquid and vapor helium by thermomechanical effect. Helium mass flow rates were measured at helium tank temperatures of 1.3, 1.5 and 1.9 K. We confirmed that resultant mass flow rates are in good agreement within the systematic error or low compared to component test results and achieve all the requirements. The film flow suppression also worked normally. Therefore, we concluded that the SXS helium vent system satisfactorily performs integrated into the dewar.

  14. A dedicated synchrotron light source for ultrafast x-ray science

    Energy Technology Data Exchange (ETDEWEB)

    Corlett, J.; DeSantis, S.; Hartman, N.; Heimann, P.; Lafever, R.; Li, D.; Padmore, H.; Rimmer, R.; Robinson, K.E.; Schoenlein, R.; Tanabe, J.; Wang, S.; Zholents, A.; Kairan, D.

    2001-06-16

    We describe a proposed femtosecond synchrotron radiation x-ray source based on a flat-beam RF gun and a recirculating superconducting linac that provides beam to an array of undulators and bend magnets. X-ray pulse durations of <100 fs at a 10 kHz repetition rate are obtained by a combination of electron pulse compression, transverse temporal correlation of the electrons, and x-ray pulse compression.

  15. Laser-Plasma Sources for Soft-X-Ray Projection Lithography

    NARCIS (Netherlands)

    F. Bijkerk,; Shmaenok, L.; Vanhonk, A.; Bastiaensen, R.; Platonov, Y. Y.; Shevelko, A. P.; Mitrofanov, A. V.; Voss, F.; Desor, R.; Frowein, H.; Nikolaus, B.

    1994-01-01

    Results are reported concerning high-repetition-rate excimer lasers with average powers up to 415 W and their usage for generating laser-plasma soft X-ray sources. A conversion efficiency of laser light into monochromatized soft X-ray radiation of 0.7% at 13.5 nm (2% bandwidth) was achieved using an

  16. Laser-Plasma Sources for Soft-X-Ray Projection Lithography

    NARCIS (Netherlands)

    F. Bijkerk,; Shmaenok, L.; Vanhonk, A.; Bastiaensen, R.; Platonov, Y. Y.; Shevelko, A. P.; Mitrofanov, A. V.; Voss, F.; Desor, R.; Frowein, H.; Nikolaus, B.

    1994-01-01

    Results are reported concerning high-repetition-rate excimer lasers with average powers up to 415 W and their usage for generating laser-plasma soft X-ray sources. A conversion efficiency of laser light into monochromatized soft X-ray radiation of 0.7% at 13.5 nm (2% bandwidth) was achieved using an

  17. A dual-energy medical instrument for measurement of x-ray source voltage and dose rate

    Science.gov (United States)

    Ryzhikov, V. D.; Naydenov, S. V.; Volkov, V. G.; Opolonin, O. D.; Makhota, S.; Pochet, T.; Smith, C. F.

    2016-03-01

    An original dual-energy detector and medical instrument have been developed to measure the output voltages and dose rates of X-ray sources. Theoretical and experimental studies were carried out to characterize the parameters of a new scintillator-photodiode sandwich-detector based on specially-prepared zinc selenide crystals in which the low-energy detector (LED) works both as the detector of the low-energy radiation and as an absorption filter allowing the highenergy fraction of the radiation to pass through to the high-energy detector (HED). The use of the LED as a low-energy filter in combination with a separate HED opens broad possibilities for such sandwich structures. In particular, it becomes possible to analyze and process the sum, difference and ratio of signals coming from these detectors, ensuring a broad (up to 106) measurement range of X-ray intensity from the source and a leveling of the energy dependence. We have chosen an optimum design of the detector and the geometry of the component LED and HED parts that allow energy-dependence leveling to within specified limits. The deviation in energy dependence of the detector does not exceed about 5% in the energy range from 30 to 120 keV. The developed detector and instrument allow contactless measurement of the anode voltage of an X-ray emitter from 40 to 140 kV with an error no greater than 3%. The dose rate measurement range is from 1 to 200 R/min. An original medical instrument has passed clinical testing and was recommended for use in medical institutions for X-ray diagnostics.

  18. High-repetition-rate optical delay line using a micromirror array and galvanometer mirror for a terahertz system.

    Science.gov (United States)

    Kitahara, Hideaki; Tani, Masahiko; Hangyo, Masanori

    2009-07-01

    We developed a high-repetition-rate optical delay line based on a micromirror array and galvanometer mirror for terahertz time-domain spectroscopy. The micromirror array is fabricated by using the x-ray lithographic technology. The measurement of terahertz time-domain waveforms with the new optical delay line is demonstrated successfully up to 25 Hz.

  19. Skull x-ray

    Science.gov (United States)

    X-ray - head; X-ray - skull; Skull radiography; Head x-ray ... There is low radiation exposure. X-rays are monitored and regulated to provide the minimum amount of radiation exposure needed to produce the image. Most ...

  20. Neck x-ray

    Science.gov (United States)

    X-ray - neck; Cervical spine x-ray; Lateral neck x-ray ... There is low radiation exposure. X-rays are monitored so that the lowest amount of radiation is used to produce the image. Pregnant women and ...

  1. Dose-rate controlled energy dispersive x-ray spectroscopic mapping of the metallic components in a biohybrid nanosystem

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Yuanyuan; Munro, Catherine J.; Olszta, Matthew J.; Edwards, Danny J.; Braunschweig, Adam B.; Knecht, Marc R.; Browning, Nigel D.

    2016-06-30

    In this work, we showcase that through precise control of the electron dose rate, state-of-the-art large solid angle energy dispersive X-ray spectroscopy (EDS) mapping in aberration-corrected scanning transmission electron microscope (STEM) is capable of faithful and unambiguous chemical characterization of the Pt and Pd distribution in a peptide-mediated nanosystem. This low-dose-rate recording scheme adds another dimension of flexibility to the design of elemental mapping experiments, and holds significant potential for extending its application to a wide variety of beam sensitive hybrid nanostructures.

  2. Thermal Disk Winds in X-Ray Binaries: Realistic Heating and Cooling Rates Give Rise to Slow, but Massive, Outflows

    Science.gov (United States)

    Higginbottom, N.; Proga, D.; Knigge, C.; Long, K. S.

    2017-02-01

    A number of X-ray binaries exhibit clear evidence for the presence of disk winds in the high/soft state. A promising driving mechanism for these outflows is mass loss driven by the thermal expansion of X-ray heated material in the outer disk atmosphere. Higginbottom & Proga recently demonstrated that the properties of thermally driven winds depend critically on the shape of the thermal equilibrium curve, since this determines the thermal stability of the irradiated material. For a given spectral energy distribution, the thermal equilibrium curve depends on an exact balance between the various heating and cooling mechanisms at work. Most previous work on thermally driven disk winds relied on an analytical approximation to these rates. Here, we use the photoionization code cloudy to generate realistic heating and cooling rates which we then use in a 2.5D hydrodynamic model computed in ZEUS to simulate thermal winds in a typical black hole X-ray binary. We find that these heating and cooling rates produce a significantly more complex thermal equilibrium curve, with dramatically different stability properties. The resulting flow, calculated in the optically thin limit, is qualitatively different from flows calculated using approximate analytical rates. Specifically, our thermal disk wind is much denser and slower, with a mass-loss rate that is a factor of two higher and characteristic velocities that are a factor of three lower. The low velocity of the flow—{v}\\max ≃ 200 km s‑1—may be difficult to reconcile with observations. However, the high mass-loss rate—15 × the accretion rate—is promising, since it has the potential to destabilize the disk. Thermally driven disk winds may therefore provide a mechanism for state changes.

  3. Binary black hole merger rates inferred from luminosity function of ultra-luminous X-ray sources

    Science.gov (United States)

    Inoue, Yoshiyuki; Tanaka, Yasuyuki T.; Isobe, Naoki

    2016-10-01

    The Advanced Laser Interferometer Gravitational-Wave Observatory (aLIGO) has detected direct signals of gravitational waves (GWs) from GW150914. The event was a merger of binary black holes whose masses are 36^{+5}_{-4} M_{{⊙}} and 29^{+4}_{-4} M_{{⊙}}. Such binary systems are expected to be directly evolved from stellar binary systems or formed by dynamical interactions of black holes in dense stellar environments. Here we derive the binary black hole merger rate based on the nearby ultra-luminous X-ray source (ULX) luminosity function (LF) under the assumption that binary black holes evolve through X-ray emitting phases. We obtain the binary black hole merger rate as 5.8(tULX/0.1 Myr)- 1λ- 0.6exp ( - 0.30λ) Gpc- 3 yr- 1, where tULX is the typical duration of the ULX phase and λ is the Eddington ratio in luminosity. This is coincident with the event rate inferred from the detection of GW150914 as well as the predictions based on binary population synthesis models. Although we are currently unable to constrain the Eddington ratio of ULXs in luminosity due to the uncertainties of our models and measured binary black hole merger event rates, further X-ray and GW data will allow us to narrow down the range of the Eddington ratios of ULXs. We also find the cumulative merger rate for the mass range of 5 M⊙ ≤ MBH ≤ 100 M⊙ inferred from the ULX LF is consistent with that estimated by the aLIGO collaboration considering various astrophysical conditions such as the mass function of black holes.

  4. FROST: a low-noise high-rate photon counting ASIC for X-ray applications

    Energy Technology Data Exchange (ETDEWEB)

    Prest, M. E-mail: prest@ts.infn.it; Vallazza, E.; Chiavacci, M.; Mariani, R.; Motto, S.; Neri, M.; Scantamburlo, N.; Arfelli, F.; Conighi, A.; Longo, R.; Olivo, A.; Pani, S.; Poropat, P.; Rashevsky, A.; Rigon, L.; Tromba, G.; Castelli, E

    2001-04-01

    FRONTier RADiography is an R and D project to assess the feasibility of digital mammography with Synchrotron Radiation at the ELETTRA Light Source in Trieste. In order to reach an acceptable time duration of the exam, a fast- and low-noise photon counting ASIC has been developed in collaboration with Aurelia Microelettronica, called Frontrad ReadOut SysTem. It is a multichannel counting system, each channel being made of a low-noise charge-sensitive preamplifier optimized for X-ray energy range (10-100 keV), a CR-RC{sup 2} shaper, a discriminator and a 16-bit counter. In order to set the discriminator threshold, a set of a global 6-bit DAC and a local (per channel) 3-bit DAC has been implemented within the ASIC. We report on the measurements done with the 8-channel prototype chip and the comparison with the simulation results.

  5. X-ray Pulsars

    CERN Document Server

    Walter, Roland

    2016-01-01

    X-ray pulsars shine thanks to the conversion of the gravitational energy of accreted material to X-ray radiation. The accretion rate is modulated by geometrical and hydrodynamical effects in the stellar wind of the pulsar companions and/or by instabilities in accretion discs. Wind driven flows are highly unstable close to neutron stars and responsible for X-ray variability by factors $10^3$ on time scale of hours. Disk driven flows feature slower state transitions and quasi periodic oscillations related to orbital motion and precession or resonance. On shorter time scales, and closer to the surface of the neutron star, X-ray variability is dominated by the interactions of the accreting flow with the spinning magnetosphere. When the pulsar magnetic field is large, the flow is confined in a relatively narrow accretion column, whose geometrical properties drive the observed X-ray emission. In low magnetized systems, an increasing accretion rate allows the ignition of powerful explosive thermonuclear burning at t...

  6. Some Like it Hot: Linking Diffuse X-Ray Luminosity, Baryonic Mass, and Star Formation Rate in Compact Groups of Galaxies

    Science.gov (United States)

    Desjardins, Tyler D.; Gallagher, Sarah C.; Hornschemeier, Ann E.; Mulchaey, John S.; Walker, Lisa May; Brandt, Willian N.; Charlton, Jane C.; Johnson, Kelsey E.; Tzanavaris, Panayiotis

    2014-01-01

    We present an analysis of the diffuse X-ray emission in 19 compact groups (CGs) of galaxies observed with Chandra. The hottest, most X-ray luminous CGs agree well with the galaxy cluster X-ray scaling relations in L(x-T) and (L(x-sigma), even in CGs where the hot gas is associated with only the brightest galaxy. Using Spitzer photometry, we compute stellar masses and classify Hickson CGs 19, 22, 40, and 42, and RSCGs 32, 44, and 86 as fossil groups using a new definition for fossil systems that includes a broader range of masses. We find that CGs with total stellar and Hi masses are great than or equal to 10(sup (11.3) solar mass are often X-ray luminous, while lower-mass CGs only sometimes exhibit faint, localized X-ray emission. Additionally, we compare the diffuse X-ray luminosity against both the total UV and 24 micron star formation rates of each CG and optical colors of the most massive galaxy in each of the CGs. The most X-ray luminous CGs have the lowest star formation rates, likely because there is no cold gas available for star formation, either because the majority of the baryons in these CGs are in stars or the X-ray halo, or due togas stripping from the galaxies in CGs with hot halos. Finally, the optical colors that trace recent star formation histories of the most massive group galaxies do not correlate with the X-ray luminosities of the CGs, indicating that perhaps the current state of the X-ray halos is independent of the recent history of stellar mass assembly in the most massive galaxies.

  7. X-ray Background at High Redshifts from Pop III Remnants: Results from Pop III star formation rates in the Renaissance Simulations

    CERN Document Server

    Xu, Hao; Norman, Michael L; Wise, John H; O'Shea, Brian W

    2016-01-01

    Due to their long mean free paths, X-rays are expected to have many significant impacts globally on the properties of the intergalactic medium (IGM) by their heating and ionizing processes on large scales. At high redshifts, X-rays from Population (Pop) III binaries might have important effects on cosmic reionization and the Lyman alpha forest. As a continuation of our previous work on Pop III binary X-rays (Xu et al. 2014), we use the Pop III distribution and evolution from the Renaissance Simulations, a suite of self-consistent cosmological radiation hydrodynamics simulations of the formation of the first galaxies, to calculate the X-ray luminosity density and background over the redshift range 20 > z > 7.6. As we find that Pop III star formation continues at a low, nearly constant rate to the end of reionization, X-rays are being continuously produced at significant rates compared to other possible X-ray sources, such as AGNs and normal X-ray binaries during the same period of time. We estimate that Pop II...

  8. Simultaneous X-ray diffraction and phase-contrast imaging for investigating material deformation mechanisms during high-rate loading.

    Science.gov (United States)

    Hudspeth, M; Sun, T; Parab, N; Guo, Z; Fezzaa, K; Luo, S; Chen, W

    2015-01-01

    Using a high-speed camera and an intensified charge-coupled device (ICCD), a simultaneous X-ray imaging and diffraction technique has been developed for studying dynamic material behaviors during high-rate tensile loading. A Kolsky tension bar has been used to pull samples at 1000 s(-1) and 5000 s(-1) strain-rates for super-elastic equiatomic NiTi and 1100-O series aluminium, respectively. By altering the ICCD gating time, temporal resolutions of 100 ps and 3.37 µs have been achieved in capturing the diffraction patterns of interest, thus equating to single-pulse and 22-pulse X-ray exposure. Furthermore, the sample through-thickness deformation process has been simultaneously imaged via phase-contrast imaging. It is also shown that adequate signal-to-noise ratios are achieved for the detected white-beam diffraction patterns, thereby allowing sufficient information to perform quantitative data analysis diffraction via in-house software (WBXRD_GUI). Of current interest is the ability to evaluate crystal d-spacing, texture evolution and material phase transitions, all of which will be established from experiments performed at the aforementioned elevated strain-rates.

  9. X-Ray Spectra of Young Pulsars and Their Wind Nebulae: Dependence on Spin-Down Energy Loss Rate

    Science.gov (United States)

    Gotthelf, E. V.

    2003-01-01

    An observational model is presented for the spectra of young rotation-powered pulsars and their nebulae based on a study of nine bright Crab-like pulsar systems observed with the Chandra X-ray observatory. A significant correlation is discovered between the X-ray spectra of these pulsars and that of their associated pulsar wind nebulae, both of which are observed to be a function of the spin-down energy loss rate, E. The 2-10 keV spectra of these objects are well characterized by an absorbed power-law model with photon indices, Gamma, in the range of 0.6 < Gamma (sub PSR) < 2.1 and 1.3 < Gamma(sub PWN) < 2.3, for the pulsars and their nebulae, respectively. A linear regression fit relating these two sets of indexes yields Gamma(sub PWN) = 0.91 +/- 0.18 + (0.66 +/- 0.11) Gamma (sub PSR), with a correlation coefficient of r = 0.97. The spectra of these pulsars are found to steepen as Gamma = Gamma(sub max) + alpha E (exp -1/2), with Gamma(sub max) providing an observational limit on the spectral slopes of young rotation-powered pulsars. These results reveal basic properties of young pulsar systems, allow new observational constraints on models of pulsar wind emission, and provide a means of predicting the energetics of pulsars lacking detected pulsations.

  10. High frame-rate real-time x-ray imaging of in situ high-velocity rifle bullets

    Science.gov (United States)

    D'Aries, Lawrence J.; Miller, Stuart R.; Robertson, Rob; Singh, Bipin; Nagarkar, Vivek V.

    2016-05-01

    High frame-rate imaging is a valuable tool for non-destructive evaluation (NDE) as well as for ballistic impact studies (terminal ballistics), in-flight projectile imaging, studies of exploding ordnance and characterization of other high-speed phenomena. Current imaging systems exist for these studies, however, none have the ability to do in-barrel characterization (in-bore ballistics) to image kinetics of the moving projectile BEFORE it exits the barrel. The system uses an intensified high-speed CMOS camera coupled to a specially designed scintillator to serve as the X-ray detector. The X-ray source is a sequentially fired portable pulsed unit synchronized with the detector integration window and is able to acquire 3,600 frames per second (fps) with mega-pixel spatial resolution and up to 500,000 fps with reduced pixel resolution. This paper will discuss our results imaging .30 caliber bullets traveling at ~1,000 m/s while still in the barrel. Information on bullet deformation, pitch, yaw and integrity are the main goals of this experimentation. Planned future upgrades for imaging large caliber projectiles will also be discussed.

  11. Ultrafast laser pump/x-ray probe experiments

    Energy Technology Data Exchange (ETDEWEB)

    Larsson, J.; Judd, E.; Schuck, P.J. [Univ. of California, Berkeley, CA (United States)] [and others

    1997-04-01

    In an ongoing project aimed at probing solids using x-rays obtained at the ALS synchrotron with a sub-picosecond time resolution following interactions with a 100 fs laser pulse, the authors have successfully performed pump-probe experiments limited by the temporal duration of ALS-pulse. They observe a drop in the diffraction efficiency following laser heating. They can attribute this to a disordering of the crystal. Studies with higher temporal resolution are required to determine the mechanism. The authors have also incorporated a low-jitter streakcamera as a diagnostic for observing time-dependant x-ray diffraction. The streakcamera triggered by a photoconductive switch was operated at kHz repetition rates. Using UV-pulses, the authors obtain a temporal response of 2 ps when averaging 5000 laser pulses. They demonstrate the ability to detect monochromatized x-ray radiation from a bend-magnet with the streak camera by measuring the pulse duration of a x-ray pulse to 70 ps. In conclusion, the authors show a rapid disordering of an InSb crystal. The resolution was determined by the duration of the ALS pulse. They also demonstrate that they can detect x-ray radiation from a synchrotron source with a temporal resolution of 2ps, by using an ultrafast x-ray streak camera. Their set-up will allow them to pursue laser pump/x-ray probe experiments to monitor structural changes in materials with ultrafast time resolution.

  12. Bit error rate analysis of X-ray communication system%X射线通信系统的误码率分析∗

    Institute of Scientific and Technical Information of China (English)

    王律强; 苏桐; 赵宝升; 盛立志; 刘永安; 刘舵

    2015-01-01

    X-ray communication, which was firstly introduced by Keithe Gendreau in 2007, is potential to compete with conventional communication methods, such as microwave and laser communication, against space surroundings. As a result, a great deal of time and effort has been devoted to making the initial idea into reality in recent years. Eventually, the X-ray communication demonstration system based on the grid-controlled X-ray source and microchannel plate detector can deliver both audio and video information in a 6-meter vacuum tunnel. The point is how to evaluate this space X-ray demonstration system in a typical experimental way. The method is to design a specific board to measure the relationship between bit-error-rate and emitting power against various communicating distances. In addition, the data should be compared with the calculation and simulation results to estimate the referred theoretical model. The concept of using X-ray as signal carriers is confirmed by our first generation X-ray communication demonstration system. Specifically, the method is to use grid-controlled emission source as a transceiver while implementing the photon counting detector which can be regarded as an important orientation of future deep-space X-ray communication applications. As the key specification of any given communication system, bit-error-rate level should be informed first. In addition, the theoretical analysis by using Poisson noise model also has been implemented to support this novel communication concept. Previous experimental results indicated that the X-ray audio demonstration system requires a 10−4 bit-error-rate level with 25 kbps communication rate. The system bit-error-rate based on on-off keying (OOK) modulation is calculated and measured, which corresponds to the theoretical calculation commendably. Another point that should be taken into consideration is the emitting energy, which is the main restriction of current X-ray communication system. The designed

  13. Chest X Ray?

    Science.gov (United States)

    ... this page from the NHLBI on Twitter. Chest X Ray A chest x ray is a fast and painless imaging test ... tissue scarring, called fibrosis. Doctors may use chest x rays to see how well certain treatments are ...

  14. X-Rays

    Science.gov (United States)

    X-rays are a type of radiation called electromagnetic waves. X-ray imaging creates pictures of the inside of ... different amounts of radiation. Calcium in bones absorbs x-rays the most, so bones look white. Fat ...

  15. Medical X-Rays

    Science.gov (United States)

    ... Benefits The discovery of X-rays and the invention of CT represented major advances in medicine. X- ... in X-ray and CT Examinations — X-ray definition, dose measurement, safety precautions, risk, and consideration with ...

  16. LUX - A recirculating linac-based ultrafast X-ray source

    Energy Technology Data Exchange (ETDEWEB)

    Corlett, J.N.; Barletta, W.A.; DeSantis, S.; Doolittle, L.; Fawley, W.M.; Green, M.A.; Heimann, P.; Leone, S.R.; Lidia, S.; Li, D.; Parmigiani, F.; Ratti, A.; Robinson, K.; Schoenlein, R.; Staples, J.; Wan, W.; Wells, R.; Wilcox, R.; Wolski, A.; Zholents, A.

    2003-08-01

    We describe the design of a proposed source of ultra-fast synchrotron radiation x-ray pulses based on a recirculating superconducting linac, with an integrated array of ultrafast laser systems. The source produces x-ray pulses with duration of 10-50 fs at a 10 kHz repetition rate, with tunability from EUV to hard x-ray regimes, and optimized for the study of ultra-fast dynamics. A high-brightness rf photocathode provides electron bunches. An injector linac accelerates the beam to the 100 MeV range, and is followed by four passes through a 700 MeV recirculating linac. Ultrafast hard x-ray pulses are obtained by a combination of electron bunch manipulation, transverse temporal correlation of the electrons, and x-ray pulse compression. EUV and soft x-ray pulses as short as 10 fs are generated in a harmonic-cascade free electron laser scheme.

  17. A miniature high repetition rate shock tube.

    Science.gov (United States)

    Tranter, R S; Lynch, P T

    2013-09-01

    A miniature high repetition rate shock tube with excellent reproducibility has been constructed to facilitate high temperature, high pressure, gas phase experiments at facilities such as synchrotron light sources where space is limited and many experiments need to be averaged to obtain adequate signal levels. The shock tube is designed to generate reaction conditions of T > 600 K, P shock waves with predictable characteristics are created, repeatably. Two synchrotron-based experiments using this apparatus are also briefly described here, demonstrating the potential of the shock tube for research at synchrotron light sources.

  18. Absorbed dose-to-water protocol applied to synchrotron-generated x-rays at very high dose rates

    Science.gov (United States)

    Fournier, P.; Crosbie, J. C.; Cornelius, I.; Berkvens, P.; Donzelli, M.; Clavel, A. H.; Rosenfeld, A. B.; Petasecca, M.; Lerch, M. L. F.; Bräuer-Krisch, E.

    2016-07-01

    Microbeam radiation therapy (MRT) is a new radiation treatment modality in the pre-clinical stage of development at the ID17 Biomedical Beamline of the European synchrotron radiation facility (ESRF) in Grenoble, France. MRT exploits the dose volume effect that is made possible through the spatial fractionation of the high dose rate synchrotron-generated x-ray beam into an array of microbeams. As an important step towards the development of a dosimetry protocol for MRT, we have applied the International Atomic Energy Agency’s TRS 398 absorbed dose-to-water protocol to the synchrotron x-ray beam in the case of the broad beam irradiation geometry (i.e. prior to spatial fractionation into microbeams). The very high dose rates observed here mean the ion recombination correction factor, k s , is the most challenging to quantify of all the necessary corrections to apply for ionization chamber based absolute dosimetry. In the course of this study, we have developed a new method, the so called ‘current ramping’ method, to determine k s for the specific irradiation and filtering conditions typically utilized throughout the development of MRT. Using the new approach we deduced an ion recombination correction factor of 1.047 for the maximum ESRF storage ring current (200 mA) under typical beam spectral filtering conditions in MRT. MRT trials are currently underway with veterinary patients at the ESRF that require additional filtering, and we have estimated a correction factor of 1.025 for these filtration conditions for the same ESRF storage ring current. The protocol described herein provides reference dosimetry data for the associated Treatment Planning System utilized in the current veterinary trials and anticipated future human clinical trials.

  19. 10th International Conference on X-Ray Lasers

    CERN Document Server

    Nickles, P.V; X-Ray Lasers 2006

    2007-01-01

    The search for table-top and repetitive pump schemes during the last decade has been the driving force behind the spectacular advances demonstrated during the 10th International Conference on X-Ray Lasers, organized in 2006 in Berlin. Since 1986, international experts have gathered every two years at this established conference to discuss the progress in theory, experiment and application of plasma-based soft X-ray lasers. Traditionally, the conference sessions devoted to complementary and alternative sources of short wavelength radiation, such as high harmonics, XFEL or incoherent X-rays are organized so as to emphasize the role of X-ray laser research in relation to the other short wavelength sources. Grazing incidence pumping (GRIP) and seeding with high harmonics were the dominant topics of the conference. High repetition rate and portable X-ray lasers were reported to have been applied in metrology and photochemistry for the first time. The proceedings of this series of conferences constitute a comprehen...

  20. Harnessing the full power of the widest Chandra field: average accretion rates of black holes in SDSS galaxies through X-ray stacking

    Science.gov (United States)

    Goulding, Andy D.; Greene, Jenny E.; Hickox, Ryan C.; Alexander, David M.; Forman, William R.; Jones, Christine; Lehmer, Bret

    2017-08-01

    Galaxy-scale bars are expected to provide an effective means for driving material towards the central region in spiral galaxies, and possibly feeding supermassive black holes (BHs). I will present our latest results on a statistically-complete study of the effect of bars on average BH accretion. From a well-selected sample of over 50,000 spiral galaxies extracted from the Sloan Digital Sky Survey, we separate those sources considered to contain galaxy-scale bars from those that do not. Using the first 16 years worth of data taken by the Chandra X-ray Observatory, we identify X-ray luminous AGN and perform the widest-area X-ray stacking analysis to date on the remaining X-ray undetected sources. Through our X-ray stacking, we derive a time-averaged look at accretion for galaxies at fixed stellar mass and star formation rate, finding that the average nuclear accretion rates of galaxies with bar structures are fully consistent with those lacking bars, and robustly concluding that large-scale bars have little or no effect on the average growth of BHs in nearby (z < 0.15) galaxies over gigayear timescales.

  1. Photo neutron dose equivalent rate in 15 MV X-ray beam from a Siemens Primus Linac

    Directory of Open Access Journals (Sweden)

    A Ghasemi

    2015-01-01

    Full Text Available Fast and thermal neutron fluence rates from a 15 MV X-ray beams of a Siemens Primus Linac were measured using bare and moderated BF 3 proportional counter inside the treatment room at different locations. Fluence rate values were converted to dose equivalent rate (DER utilizing conversion factors of American Association of Physicist in Medicine′s (AAPM report number 19. For thermal neutrons, maximum and minimum DERs were 3.46 × 10 -6 (3 m from isocenter in +Y direction, 0 × 0 field size and 8.36 × 10 -8 Sv/min (in maze, 40 × 40 field size, respectively. For fast neutrons, maximum DERs using 9" and 3" moderators were 1.6 × 10 -5 and 1.74 × 10 -5 Sv/min (2 m from isocenter in +Y direction, 0 × 0 field size, respectively. By changing the field size, the variation in thermal neutron DER was more than the fast neutron DER and the changes in fast neutron DER were not significant in the bunker except inside the radiation field. This study showed that at all points and distances, by decreasing field size of the beam, thermal and fast neutron DER increases and the number of thermal neutrons is more than fast neutrons.

  2. Photo neutron dose equivalent rate in 15 MV X-ray beam from a Siemens Primus Linac.

    Science.gov (United States)

    Ghasemi, A; Pourfallah, T Allahverdi; Akbari, M R; Babapour, H; Shahidi, M

    2015-01-01

    Fast and thermal neutron fluence rates from a 15 MV X-ray beams of a Siemens Primus Linac were measured using bare and moderated BF3 proportional counter inside the treatment room at different locations. Fluence rate values were converted to dose equivalent rate (DER) utilizing conversion factors of American Association of Physicist in Medicine's (AAPM) report number 19. For thermal neutrons, maximum and minimum DERs were 3.46 × 10(-6) (3 m from isocenter in +Y direction, 0 × 0 field size) and 8.36 × 10(-8) Sv/min (in maze, 40 × 40 field size), respectively. For fast neutrons, maximum DERs using 9" and 3" moderators were 1.6 × 10(-5) and 1.74 × 10(-5) Sv/min (2 m from isocenter in +Y direction, 0 × 0 field size), respectively. By changing the field size, the variation in thermal neutron DER was more than the fast neutron DER and the changes in fast neutron DER were not significant in the bunker except inside the radiation field. This study showed that at all points and distances, by decreasing field size of the beam, thermal and fast neutron DER increases and the number of thermal neutrons is more than fast neutrons.

  3. A Jet Break in the X-ray Light Curve of Short GRB 111020A: Implications for Energetics and Rates

    CERN Document Server

    Fong, Wen-fai; Margutti, Raffaella; Zauderer, B Ashley; Troja, Eleonora; Czekala, Ian; Chornock, Ryan; Gehrels, Neil; Sakamoto, Takanori; Fox, Derek B; Podsiadlowski, Philipp

    2012-01-01

    We present broad-band observations of the afterglow and environment of the short GRB 111020A. An extensive X-ray light curve from Swift/XRT, XMM-Newton and Chandra, spanning ~100 seconds to 10 days after the burst, reveals a significant break at t~2 days with pre- and post-break decline rates of alphaX,1 ~ -0.78 and alphaX,224.4 mag at 18 hours after the burst, and reveal a potential host galaxy with i~24.3 mag. The sub-arcsecond localization from Chandra provides a precise offset of 0.80"+/-0.11" (1-sigma) from this galaxy corresponding to an offset of 5-7 kpc for z=0.5-1.5. We find a high excess neutral Hydrogen column density of (7.5+/-2.0)e21 cm^(-2) (z=0). Our observations demonstrate that a growing fraction of short GRBs are collimated which may lead to a true event rate of >100-1000 Gpc^(-3) yr^(-1), in good agreement with the NS-NS merger rate of ~200-3000 Gpc^(-3) yr^(-1). This consistency is promising for coincident short GRB-gravitational wave searches in the forthcoming era of Advanced LIGO/VIRGO.

  4. 13th International Conference on X-Ray Lasers

    CERN Document Server

    Gautier, Julien; Ros, David; Zeitoun, Philippe

    2014-01-01

    These proceedings comprise of invited and contributed papers presented at the 13th International Conference on X-Ray Lasers (ICXRL 2012) which was held 11–15 June 2012 in Paris, in the famous Quartier Latin, inside the historical Center of Cordeliers. This conference is part of a continuing series dedicated to recent developments and applications of x-ray lasers and other coherent x-ray sources with attention to supporting technologies and instrumentation. New results in the generation of intense, coherent x-rays and progress towards practical devices and their applications are reported in these proceedings, including areas of research in plasma-based x-ray lasers, 4th generation accelerator-based sources and higher harmonic generation. Recent achievements related to the increase of the repetition rate up to 100 Hz and shorter wavelength collisional plasma-based soft x-ray lasers down to about 7 nm are presented. Seeding the amplifying plasma with a femtosecond high-order harmonic of infrared laser was fore...

  5. Lasers, extreme UV and soft X-ray

    Energy Technology Data Exchange (ETDEWEB)

    Nilsen, Joseph [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2015-09-20

    Three decades ago, large ICF lasers that occupied entire buildings were used as the energy sources to drive the first X-ray lasers. Today X-ray lasers are tabletop, spatially coherent, high-repetition rate lasers that enable many of the standard optical techniques such as interferometry to be extended to the soft X-ray regime between wavelengths of 10 and 50 nm. Over the last decade X-ray laser performance has been improved by the use of the grazing incidence geometry, diode-pumped solid-state lasers, and seeding techniques. The dominant X-ray laser schemes are the monopole collisional excitation lasers either driven by chirped pulse amplification (CPA) laser systems or capillary discharge. The CPA systems drive lasing in neon-like or nickel-like ions, typically in the 10 – 30 nm range, while the capillary system works best for neon-like argon at 46.9 nm. Most researchers use nickel-like ion lasers near 14 nm because they are well matched to the Mo:Si multilayer mirrors that have peak reflectivity near 13 nm and are used in many applications. As a result, the last decade has seen the birth of the X-ray free electron laser (XFEL) that can reach wavelengths down to 0.15 nm and the inner-shell Ne laser at 1.46 nm.

  6. Increase in recombination rate in Arabidopsis thaliana plants sharing gaseous environment with X-ray and UVC-irradiated plants depends on production of radicals.

    Science.gov (United States)

    Zemp, Franz J; Sidler, Corinne; Kovalchuk, Igor

    2012-07-01

    X-ray and UVC are the two physical agents that damage DNA directly, with both agents capable of inducing double-strand breaks. Some of our recent work has demonstrated that local exposure to UVC results in a systemic increase in recombination frequency, suggesting that information about exposure can be passed from damaged to non-damaged tissue. Indeed, we recently showed that plants sharing the same enclosed environment with UVC-irradiated plants exhibit similar increase in homologous recombination frequency as irradiated plants. Here, we further tested whether yet another DNA-damaging agent, X-ray, is capable of increasing recombination rate (RR) in neighboring plants grown in a Petri dish. To test this, we grew plants exposed to X-ray or UVC irradiation in an enclosed environment next to non-exposed plants. We found that both X-ray and UVC-irradiated plants and neighboring plants exhibited comparable increases in the levels of strand breaks and the RR. We further showed that pre-exposure of plants to radical scavenger DMSO substantially alleviates the radiation-induced increase in RR and prevents formation of bystander signal. Our results suggest that the increase in RR in bystander plants can also be triggered by X-ray and that radicals may play some role in initiation or maintenance of this signal.

  7. A Chandra Perspective On Galaxy-Wide X-ray Binary Emission And Its Correlation With Star Formation Rate And Stellar Mass: New Results From Luminous Infrared Galaxies

    CERN Document Server

    Lehmer, B D; Bauer, F E; Brandt, W N; Goulding, A D; Jenkins, L P; Ptak, A; Roberts, T P

    2010-01-01

    We present new Chandra observations that complete a sample of seventeen (17) luminous infrared galaxies (LIRGs) with D < 60 Mpc and low Galactic column densities of N_H < 5 X 10^20 cm^-2. The LIRGs in our sample have total infrared (8-1000um) luminosities in the range of L_IR ~ (1-8) X 10^11 L_sol. The high-resolution imaging and X-ray spectral information from our Chandra observations allow us to measure separately X-ray contributions from active galactic nuclei (AGNs) and normal galaxy processes (e.g., X-ray binaries and hot gas). We utilized total infrared plus UV luminosities to estimate star-formation rates (SFRs) and K-band luminosities and optical colors to estimate stellar masses (M*) for the sample. Under the assumption that the galaxy-wide 2-10 keV luminosity (LX) traces the combined emission from high mass X-ray binaries (HMXBs) and low mass X-ray binaries (LMXBs), and that the power output from these components are linearly correlated with SFR and M*, respectively, we constrain the relation ...

  8. A high repetition rate XUV seeding source for FLASH2

    Energy Technology Data Exchange (ETDEWEB)

    Willner, Arik

    2012-05-15

    Improved performance of free-electron laser (FEL) light sources in terms of timing stability, pulse shape and spectral properties of the amplified FEL pulses is of interest in material science, the fields of ultrafast dynamics, biology, chemistry and even special branches in industry. A promising scheme for such an improvement is direct seeding with high harmonic generation (HHG) in a noble gas target. A free-electron laser seeded by an external extreme ultraviolet (XUV) source is planned for FLASH2 at DESY in Hamburg. The requirements for the XUV/soft X-ray source can be summarized as follows: A repetition rate of at least 100 kHz in a 10 Hz burst is needed at variable wavelengths from 10 to 40 nm and pulse energies of several nJ within a single laser harmonic. This application requires a laser amplifier system with exceptional parameters, mJ-level pulse energy, 10-15 fs pulse duration at 100 kHz (1 MHz) burst repetition rate. A new optical parametric chirped-pulse amplification (OPCPA) system is under development in order to meet these requirements, and very promising results have been achieved in the last three years. In parallel to this development, a new HHG concept is necessary to sustain high average power of the driving laser system and to generate harmonics with high conversion efficiencies. Currently, the highest conversion efficiency with HHG has been demonstrated using gas-filled capillary targets. For our application, only a free-jet target can be used for HHG, in order to overcome damage threshold limitations of HHG target optics at a high repetition rate. A novel dual-gas multijet gas target has been developed and first experiments show remarkable control of the degree of phase matching forming the basis for improved control of the harmonic photon flux and the XUV pulse characteristics. The basic idea behind the dual-gas concept is the insertion of matching zones in between multiple HHG sources. These matching sections are filled with hydrogen which

  9. Characterization of MHz pulse repetition rate femtosecond laser-irradiated gold-coated silicon surfaces

    Directory of Open Access Journals (Sweden)

    Venkatakrishnan Krishnan

    2011-01-01

    Full Text Available Abstract In this study, MHz pulse repetition rate femtosecond laser-irradiated gold-coated silicon surfaces under ambient condition were characterized by scanning electron microscopy (SEM, transmission electron microscopy (TEM, X-ray diffraction analysis (XRD, and X-ray photoelectron spectroscopy (XPS. The radiation fluence used was 0.5 J/cm2 at a pulse repetition rate of 25 MHz with 1 ms interaction time. SEM analysis of the irradiated surfaces showed self-assembled intermingled weblike nanofibrous structure in and around the laser-irradiated spots. Further TEM investigation on this nanostructure revealed that the nanofibrous structure is formed due to aggregation of Au-Si/Si nanoparticles. The XRD peaks at 32.2°, 39.7°, and 62.5° were identified as (200, (211, and (321 reflections, respectively, corresponding to gold silicide. In addition, the observed chemical shift of Au 4f and Si 2p lines in XPS spectrum of the irradiated surface illustrated the presence of gold silicide at the irradiated surface. The generation of Si/Au-Si alloy fibrous nanoparticles aggregate is explained by the nucleation and subsequent condensation of vapor in the plasma plume during irradiation and expulsion of molten material due to high plasma pressure.

  10. Extremity x-ray

    Science.gov (United States)

    ... degenerative) Bone tumor Broken bone (fracture) Dislocated bone Osteomyelitis (infection) Arthritis Other conditions for which the test ... Bone tumor Bone x-ray Broken bone Clubfoot Osteomyelitis X-ray Review Date 7/3/2016 Updated ...

  11. Abdominal x-ray

    Science.gov (United States)

    ... are, or may be, pregnant. Alternative Names Abdominal film; X-ray - abdomen; Flat plate; KUB x-ray ... Assistant Studies, Department of Family Medicine, UW Medicine, School of Medicine, University of Washington, Seattle, WA. Also ...

  12. Numerical Modeling on Thermal Loading of Diamond Crystal in X-ray FEL Oscillator

    CERN Document Server

    Song, Meiqi; Guo, Yuhang; Li, Kai; Deng, Haixiao

    2015-01-01

    Due to high reflectivity and high resolution to X-ray pulse, diamond is one of the most popular Bragg crystals serving as the reflecting mirror and mono-chromator in the next generation free electrons lasers (FELs). The energy deposition of X-rays will result in thermal heating, and thus lattice expanding of diamond crystal, which may degrade the performance of X-ray FELs. In this paper, the thermal loading effect of diamond crystal for X-ray FEL oscillator has been systematically studied by the combined simulation of Geant4 and ANSYS, and its dependence on the environment temperature, crystal size, X-ray pulse repetition rate and pulse energy are presented.

  13. Overview of Tabletop X-ray Laser Development at the Lawrence Livermore National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Dunn, J; Shlyaptsev, V; Nilsen, J; Smith, R; Keenan, R; Moon, S; Filevich, J; Rocca, J; Nelson, A; Hunter, J; Marconi, M; Li, Y; Osterheld, A; Shepherd, R; Fiedorowicz, H; Bartnik, A; Faenov, A Y; Pikuz, T; Zeitoun, P; Hubert, S; Jacquemot, S; Fajardo, M

    2006-11-03

    It is almost a decade since the first tabletop x-ray laser experiments were implemented at the Lawrence Livermore National Laboratory (LLNL). The decision to pursue the picosecond-driven schemes at LLNL was largely based around the early demonstration of the tabletop Ne-like Ti x-ray laser at the Max Born Institute (MBI) as well as the established robustness of collisional excitation schemes. These picosecond x-ray lasers have been a strong growth area for x-ray laser research. Rapid progress in source development and characterization has achieved ultrahigh peak brightness rivaling the previous activities on the larger facilities. Various picosecond soft-x-ray based applications have benefited from the increased repetition rates. We will describe the activities at LLNL in this area.

  14. S-band linac-based X-ray source with {pi}/2-mode electron linac

    Energy Technology Data Exchange (ETDEWEB)

    Deshpande, Abhay, E-mail: abhay@post.kek.jp [Department of Accelerator Science, School of High Energy Accelerator Science, Graduate University for Advanced Studies, Shonan International Village, Hayama, Miura, Kanagawa 240-0193 (Japan); Society for Applied Microwave Electronic Engineering and Research (SAMEER), R and D Laboratory of the Government of India, IIT Campus, Powai, Mumbai 400 076 (India); Araki, Sakae [High Energy Accelerator Research Organization, 1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan); Dixit, Tanuja [Society for Applied Microwave Electronic Engineering and Research (SAMEER), R and D Laboratory of the Government of India, IIT Campus, Powai, Mumbai 400 076 (India); Fukuda, Masafumi [High Energy Accelerator Research Organization, 1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan); Krishnan, R; Pethe, Sanjay [Society for Applied Microwave Electronic Engineering and Research (SAMEER), R and D Laboratory of the Government of India, IIT Campus, Powai, Mumbai 400 076 (India); Sakaue, Kazuyuki [Waseda University, Shinjuku-ku, Tokyo 169-8555 (Japan); Terunuma, Nobuhiro; Urakawa, Junji [High Energy Accelerator Research Organization, 1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan); Washio, Masakazu [Waseda University, Shinjuku-ku, Tokyo 169-8555 (Japan)

    2011-05-01

    The activities with the compact X-ray source are attracting more attention, particularly for the applications of the source in medical fields. We propose the fabrication of a compact X-ray source using the SAMEER electron linear accelerator and the KEK laser undulator X-ray source (LUCX) technologies. The linac developed at SAMEER is a standing wave side-coupled S-band linac operating in the {pi}/2 mode. In the proposed system, a photocathode RF gun will inject bunches of electrons in the linac to accelerate and achieve a high-energy, low-emittance beam. This beam will then interact with the laser in the laser cavity to produce X-rays of a type well suited for various applications. The side-coupled structure will make the system more compact, and the {pi}/2 mode of operation will enable a high repetition rate operation, which will help to increase the X-ray yield.

  15. 11th International Conference on X-Ray Lasers

    CERN Document Server

    Lewis, Ciaran L. S; X-Ray Lasers 2008

    2009-01-01

    This book provides a thorough account of the current status of achievements made in the area of soft X-ray laser source development and of the increasingly diverse applications being demonstrated using such radiation sources. There is significant effort worldwide to develop very bright, short duration radiation sources in the X-ray spectral region – driven by the multitude of potential applications in all branches of science. This book contains updates on several different approaches for comparative purposes but concentrates on developments in the area of laser-produced plasmas, whereby transient population inversion and gain between ion states is pumped by optical lasers interacting with pre-formed plasmas. The most significant development here is the demonstrated increasing feasibility to produce useful soft X-ray laser beams with high repetition rates in a typical, small, university-class laboratory – as opposed to the requirement of access to a national facility some 20 years ago. Experimental progres...

  16. Early effects comparison of X-rays delivered at high-dose-rate pulses by a plasma focus device and at low dose rate on human tumour cells.

    Science.gov (United States)

    Virelli, A; Zironi, I; Pasi, F; Ceccolini, E; Nano, R; Facoetti, A; Gavoçi, E; Fiore, M R; Rocchi, F; Mostacci, D; Cucchi, G; Castellani, G; Sumini, M; Orecchia, R

    2015-09-01

    A comparative study has been performed on the effects of high-dose-rate (DR) X-ray beams produced by a plasma focus device (PFMA-3), to exploit its potential medical applications (e.g. radiotherapy), and low-DR X-ray beams produced by a conventional source (XRT). Experiments have been performed at 0.5 and 2 Gy doses on a human glioblastoma cell line (T98G). Cell proliferation rate and potassium outward currents (IK) have been investigated by time lapse imaging and patch clamp recordings. The results showed that PFMA-3 irradiation has a greater capability to reduce the proliferation rate activity with respect to XRT, while it does not affect IK of T98G cells at any of the dose levels tested. XRT irradiation significantly reduces the mean IK amplitude of T98G cells only at 0.5 Gy. This work confirms that the DR, and therefore the source of radiation, is crucial for the planning and optimisation of radiotherapy applications.

  17. Tabletop Ultrabright Kiloelectronvolt X-Ray Sources from Xe and Kr Hollow Atom States

    Science.gov (United States)

    Sankar, Poopalasingam

    Albert Einstein, the father of relativity, once said, "Look deep into nature, and then you will understand everything better". Today available higher resolution tabletop tool to look deep into matters and living thing is an x-ray source. Although the available tabletop x-rays sources of the 20th century, such as the ones used for medical or dental x-rays are tremendously useful for medical diagnostics and industry, a major disadvantage is that they have low quality skillful brightness, which limits its resolution and accuracy. In the other hand, x-ray free-electrons laser (XFEL) and synchrotron radiation sources provided extreme bright x-rays. However, number of applications of XFEL and synchrotron such as medical and industrials, has been hampered by their size, complexity, and cost. This has set a goal of demonstrating x-ray source with enough brightness for potential applications in an often-called tabletop compact x-ray source that could be operated in university laboratory or hospitals. We have developed two tabletop ultrabright keV x-ray sources, one from a Xe hollow-atom states and the other one from Kr hollow-atom stares with a unique characteristic that makes them complementary to currently-available extreme-light sources; XFEL, and synchrotron x-ray source. Upgraded tabletop ultra-fast KrF* pump-laser interacts with target rare-gas clusters and produces hollow-atom states, which later coherently collapse to the empty inner-shell and thereby generate keV x-ray radiation. The KrF* pump-laser beam is self-focused and forms a self-channel to guide the generated x-ray radiation in the direction of the pump-laser beam to produce directed x-ray beam. Xe (M) x-ray source operates at 1.2-1.6 nm wavelength while the Kr(L) x-ray source operates in 600-800 pm wavelength. System is mounted upon 3 optical-tables (5´x12´) with two KrF amplifiers at a repetition rate of 0.1 Hz. A lower bound for brightness value for both Xe and Kr x-ray sources is 1026 photons s-1mm-2

  18. K(alpha) x-ray emission characterization of 100 Hz, 15 mJ femtosecond laser system with high contrast ratio.

    Science.gov (United States)

    Fourmaux, S; Serbanescu, C; Kincaid, R E; Krol, A; Kieffer, J C

    2008-12-12

    We report K(alpha) x-ray production with a high energy (110 mJ per pulse at 800 nm before compression/15 mJ at 400 nm after compression), high repetition rate (100 Hz), and high pulse contrast (better than 10(-9) at 400 nm) laser system. To develop laser-based x-ray sources for biomedical imaging requires to use high-energy and high-power ultra-fast laser system where compression is achieved under vacuum. Using this type of laser system, we demonstrate long-term stability of the x-ray yield, conversion efficiency higher than 1.5 x 10(-5) with a Mo target, and the x-ray spot size close to the optical focal spot. This high-repetition K(alpha) x-ray source can be very useful for x-ray phase-contrast imaging.

  19. Ultrafast x-ray diffraction of laser-irradiated crystals

    Science.gov (United States)

    Heimann, P. A.; Larsson, J.; Chang, Z.; Lindenberg, A.; Schuck, P. J.; Judd, E.; Padmore, H. A.; Bucksbaum, P. H.; Lee, R. W.; Murnane, M.; Kapteyn, H.; Wark, J. S.; Falcone, R. W.

    1997-07-01

    An apparatus has been developed for measuring time-dependent x-ray diffraction. X-ray pulses from an Advanced Light Source bend magnet are diffracted by a sagittally-focusing Si (111) crystal and then by a sample crystal, presently InSb (111). Laser pulses with 100 fs duration and a repetition rate of 1 KHz irradiate the sample inducing a phase transition. Two types of detectors are being employed: an x-ray streak camera and an avalanche photodiode. The streak camera is driven by a photoconductive switch and has a 2 ps temporal resolution determined by trigger jitter. The avalanche photodiode has high quantum efficiency and sufficient time resolution to detect single x-ray pulses in ALS two bunch or `camshaft' operation. A beamline is under construction dedicated for time resolved and micro-diffraction experiments. In the new beamline a toroidal mirror collects 3 mrad horizontally and makes a 1:1 image of the bend magnet source in the x-ray hutch. A laser induced phase transition has been observed in InSb occurring within 70 ps.

  20. Optical Shaping of X-Ray Free-Electron Lasers

    Science.gov (United States)

    Marinelli, A.; Coffee, R.; Vetter, S.; Hering, P.; West, G. N.; Gilevich, S.; Lutman, A. A.; Li, S.; Maxwell, T.; Galayda, J.; Fry, A.; Huang, Z.

    2016-06-01

    In this Letter we report the experimental demonstration of a new temporal shaping technique for x-ray free-electron lasers (FELs). This technique is based on the use of a spectrally shaped infrared (IR) laser and allows optical control of the x-ray generation process. By accurately manipulating the spectral amplitude and phase of the IR laser, we can selectively modify the electron bunch longitudinal emittance thus controlling the duration of the resulting x-ray pulse down to the femtosecond time scale. Unlike other methods currently in use, optical shaping is directly applicable to the next generation of high-average power x-ray FELs such as the Linac Coherent Light Source-II or the European X-FEL, and it enables pulse shaping of FELs at the highest repetition rates. Furthermore, this laser-shaping technique paves the way for flexible tailoring of complex multicolor FEL pulse patterns required for nonlinear multidimensional x-ray spectroscopy as well as novel multicolor diffraction imaging schemes.

  1. Soliton repetition rate in a silicon-nitride microresonator

    CERN Document Server

    Bao, Chengying; Wang, Cong; Jaramillo-Villegas, Jose A; Leaird, Daniel E; Qi, Minghao; Weiner, Andrew M

    2016-01-01

    The repetition rate of a Kerr comb comprising a single soliton in an anomalous dispersion silicon nitride microcavity is measured as a function of pump frequency tuning. The contributions from the Raman soliton self-frequency shift (SSFS) and from thermal effects are evaluated both experimentally and theoretically; the SSFS is found to dominate the changes in repetition rate. The relationship between the changes in repetition rate and pump frequency detuning is found to be independent of the nonlinearity coefficient and dispersion of the cavity. Modeling of the repetition rate change by using the generalized Lugiato-Lefever equation is discussed; the Kerr shock is found to have only a minor effect on repetition rate for cavity solitons with duration down to ~50 fs.

  2. Soliton repetition rate in a silicon-nitride microresonator.

    Science.gov (United States)

    Bao, Chengying; Xuan, Yi; Wang, Cong; Jaramillo-Villegas, Jose A; Leaird, Daniel E; Qi, Minghao; Weiner, Andrew M

    2017-02-15

    The repetition rate of a Kerr comb composed of a single soliton in an anomalous group velocity dispersion silicon-nitride microcavity is measured as a function of pump frequency. By comparing operation in the soliton and non-soliton states, the contributions from the Raman soliton self-frequency shift (SSFS) and the thermal effects are evaluated; the SSFS is found to dominate the changes in the repetition rate, similar to silica cavities. The relationship between the changes in the repetition rate and the pump frequency detuning is found to be independent of the nonlinearity coefficient and dispersion of the cavity. Modeling of the repetition rate change by using the generalized Lugiato-Lefever equation is discussed; the Kerr shock is found to have only a minor effect on repetition rate for cavity solitons with duration down to ∼50  fs.

  3. X-Ray Polarimetry

    CERN Document Server

    Kaaret, Philip

    2014-01-01

    We review the basic principles of X-ray polarimetry and current detector technologies based on the photoelectric effect, Bragg reflection, and Compton scattering. Recent technological advances in high-spatial-resolution gas-filled X-ray detectors have enabled efficient polarimeters exploiting the photoelectric effect that hold great scientific promise for X-ray polarimetry in the 2-10 keV band. Advances in the fabrication of multilayer optics have made feasible the construction of broad-band soft X-ray polarimeters based on Bragg reflection. Developments in scintillator and solid-state hard X-ray detectors facilitate construction of both modular, large area Compton scattering polarimeters and compact devices suitable for use with focusing X-ray telescopes.

  4. Generation of low-timing-jitter femtosecond pulse trains with 2 GHz repetition rate via external repetition rate multiplication.

    Science.gov (United States)

    Chen, Jian; Sickler, Jason W; Fendel, Peter; Ippen, Erich P; Kärtner, Franz X; Wilken, Tobias; Holzwarth, Ronald; Hänsch, Theodor W

    2008-05-01

    Generation of low-timing-jitter 150 fs pulse trains at 1560 nm with 2 GHz repetition rate is demonstrated by locking a 200 MHz fundamental polarization additive-pulse mode-locked erbium fiber laser to high-finesse external Fabry-Perot cavities. The timing jitter and relative intensity noise of the repetition-rate multiplied pulse train are investigated.

  5. Special Issue Devoted to the 80TH ANNIVERSARY of Academician N G Basov's Birth: Multilayer X-ray optics

    Science.gov (United States)

    Vinogradov, Aleksandr V.

    2002-12-01

    The principles, state of the art, and problems of multilayer X-ray optics are analysed. Among its applications, the projection X-ray lithography and mirrors for a repetitively pulsed capillary-discharge X-ray laser are considered.

  6. A large spin-up rate measured with INTEGRAL in the High Mass X-ray Binary Pulsar SAXJ2103.5+4545

    CERN Document Server

    Sidoli, L; Larsson, S; Chernyakova, M; Kreykenbohm, I; Kretschmar, P; Paizis, A; Santangelo, A; Ferrigno, C; Falanga, M

    2005-01-01

    The High Mass X-ray Binary Pulsar SAXJ2103.5+4545 has been observed with INTEGRAL several times during the last outburst in 2002-2004. We report a comprehensive study of all INTEGRAL observations, allowing a study of the pulse period evolution during the recent outburst. We measured a very rapid spin-up episode, lasting 130days, which decreased the pulse period by 1.8s. The spin-up rate, pdot=-1.5e-7 s/s, is the largest ever measured for SAXJ2103.5+4545, and it is among the fastest for an accreting pulsar. The pulse profile shows evidence for temporal variability, apparently not related to the source flux or to the orbital phase. The X-ray spectrum is hard and there is significant emission up to 150keV. A new derivation of the orbital period, based on RXTE data, is also reported.

  7. Investigation of quad-energy high-rate photon counting for X-ray computed tomography using a cadmium telluride detector.

    Science.gov (United States)

    Matsukiyo, Hiroshi; Sato, Eiichi; Oda, Yasuyuki; Yamaguchi, Satoshi; Sato, Yuichi; Hagiwara, Osahiko; Enomoto, Toshiyuki; Watanabe, Manabu; Kusachi, Shinya

    2017-09-10

    To obtain four kinds of tomograms at four different X-ray energy ranges simultaneously, we have constructed a quad-energy (QE) X-ray photon counter with a cadmium telluride (CdTe) detector and four sets of comparators and microcomputers (MCs). X-ray photons are detected using the CdTe detector, and the event pulses produced using amplifiers are sent to four comparators simultaneously to regulate four threshold energies of 20, 33, 50 and 65keV. Using this counter, the energy ranges are 20-33, 33-50, 50-65 and 65-100keV; the maximum energy corresponds to the tube voltage. We performed QE computed tomography (QE-CT) at a tube voltage of 100kV. Using a 0.5-mm-diam lead pinhole, four tomograms were obtained simultaneously at four energy ranges. K-edge CT using iodine and gadolinium media was carried out utilizing two energy ranges of 33-50 and 50-65keV, respectively. At a tube voltage of 100kV and a current of 60 μA, the count rate was 15.2 kilocounts per second (kcps), and the minimum count rates after penetrating objects in QE-CT were regulated to approximately 2 kcps by the tube current. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. X-Ray

    Science.gov (United States)

    ... You may be allowed to remain with your child during the test. If you remain in the room during the X-ray exposure, you'll likely be asked to wear a lead apron to shield you from unnecessary exposure. After the X-ray ...

  9. Dental x-rays

    Science.gov (United States)

    ... X-rays are a form of high energy electromagnetic radiation. The x-rays penetrate the body to form ... for detecting cavities, unless the decay is very advanced and deep. Many ... The amount of radiation given off during the procedure is less than ...

  10. Machine learning applied to single-shot x-ray diagnostics in an XFEL

    CERN Document Server

    Sanchez-Gonzalez, A; Olivier, C; Barillot, T R; Ilchen, M; Lutman, A A; Marinelli, A; Maxwell, T; Achner, A; Agåker, M; Berrah, N; Bostedt, C; Buck, J; Bucksbaum, P H; Montero, S Carron; Cooper, B; Cryan, J P; Dong, M; Feifel, R; Frasinski, L J; Fukuzawa, H; Galler, A; Hartmann, G; Hartmann, N; Helml, W; Johnson, A S; Knie, A; Lindahl, A O; Liu, J; Motomura, K; Mucke, M; O'Grady, C; Rubensson, J-E; Simpson, E R; Squibb, R J; Såthe, C; Ueda, K; Vacher, M; Walke, D J; Zhaunerchyk, V; Coffee, R N; Marangos, J P

    2016-01-01

    X-ray free-electron lasers (XFELs) are the only sources currently able to produce bright few-fs pulses with tunable photon energies from 100 eV to more than 10 keV. Due to the stochastic SASE operating principles and other technical issues the output pulses are subject to large fluctuations, making it necessary to characterize the x-ray pulses on every shot for data sorting purposes. We present a technique that applies machine learning tools to predict x-ray pulse properties using simple electron beam and x-ray parameters as input. Using this technique at the Linac Coherent Light Source (LCLS), we report mean errors below 0.3 eV for the prediction of the photon energy at 530 eV and below 1.6 fs for the prediction of the delay between two x-ray pulses. We also demonstrate spectral shape prediction with a mean agreement of 97%. This approach could potentially be used at the next generation of high-repetition-rate XFELs to provide accurate knowledge of complex x-ray pulses at the full repetition rate.

  11. X-Ray Surveys

    CERN Document Server

    Giommi, P; Perri, M

    1998-01-01

    A review of recent developments in the field of X-ray surveys, especially in the hard (2-10 and 5-10 keV) bands, is given. A new detailed comparison between the measurements in the hard band and extrapolations from ROSAT counts, that takes into proper account the observed distribution of spectral slopes, is presented. Direct comparisons between deep ROSAT and BeppoSAX images show that most hard X-ray sources are also detected at soft X-ray energies. This may indicate that heavily cutoff sources, that should not be detectable in the ROSAT band but are expected in large numbers from unified AGN schemes, are in fact detected because of the emerging of either non-nuclear components, or of reflected, or partially transmitted nuclear X-rays. These soft components may complicate the estimation of the soft X-ray luminosity function and cosmological evolution of AGN.

  12. X-ray Polarimetry

    Science.gov (United States)

    Kallman, T.

    In spite of the recent advances in X-ray instrumentation, polarimetry remains an area which has been virtually unexplored in the last 20 years. The scientific motivation to study polarization has increased during this time: emission models designed to repro- duce X-ray spectra can be tested using polarization, and polarization detected in other wavelength bands makes clear predictions as to the X-ray polarization. Polarization remains the only way to infer geometrical properties of sources which are too small to be spatially resolved. At the same time, there has been recent progress in instrumen- tation which is likely to allow searches for X-ray polarization at levels significantly below what was possible for early detectors. In this talk I will review the history of X-ray polarimetry, discuss some experimental techniques and the scientific problems which can be addressed by future experiments.

  13. Design Studies for a High-Repetition-Rate FEL Facility at LBNL.

    Energy Technology Data Exchange (ETDEWEB)

    CORLETT, J.; BELKACEM, A.; BYRD, J. M.; FAWLEY, W.; KIRZ, J.; LIDIA, S.; MCCURDY, W.; PADMORE, H.; PENN, G.; POGORELOV, I.; QIANG, J.; ROBIN, D.; SANNIBALE, F.; SCHOENLEIN, R.; STAPLES, J.; STEIER, C.; VENTURINI, M.; WAN, W.; WILCOX, R.; ZHOLENTS, A.

    2007-10-04

    Lawrence Berkeley National Laboratory (LBNL) is working to address the needs of the primary scientific Grand Challenges now being considered by the U.S. Department of Energy, Office of Basic Energy Sciences: we are exploring scientific discovery opportunities, and new areas of science, to be unlocked with the use of advanced photon sources. A partnership of several divisions at LBNL is working to define the science and instruments needed in the future. To meet these needs, we propose a seeded, high-repetition-rate, free-electron laser (FEL) facility. Temporally and spatially coherent photon pulses, of controlled duration ranging from picosecond to sub-femtosecond, are within reach in the vacuum ultraviolet (VUV) to soft X-ray regime, and LBNL is developing critical accelerator physics and technologies toward this goal. We envision a facility with an array of FELs, each independently configurable and tunable, providing a range of photon-beam properties with high average and peak flux and brightness.

  14. Emission rates of Gd L sub-shell proton induced X-rays as a function of projectile energy

    Energy Technology Data Exchange (ETDEWEB)

    Canto, C.E.; Lucio, O.G. de, E-mail: olucio@comunidad.unam.mx; Pineda, J.C.

    2013-11-15

    In this work, relative intensities of Gd characteristic L X-ray were measured, which were induced by proton bombardment over a thin film made by deposition of GdF{sub 3} over a pyrolytic carbon substrate. Relative intensities were recorded as a function of the proton energy (ranging from 200 to 700 keV) and also as a function of a parameter defined as the reduced velocity of the incident particle. Results are presented as intensity ratios for the different L transitions observed, measured with respect to the total number of X-ray photons recorded; the energy dependence of the intensity ratios (L{sub β}/L{sub α},L{sub γ}/L{sub α},L{sub γ}/L{sub β},L{sub l}/L{sub α},L{sub l}/L{sub γ}) is shown and acquired data is compared with similar previous measurements, as well as with theoretical predictions [1] based on the ECPSSR theory and a 4th degree polynomial fit of data; a comparison between theoretical predictions and the polynomial fit was performed in order to provide an empirical correcting factor.

  15. Effect of the rate of rise in discharge current on the output of a 46.9-nm soft X-ray laser based on capillary discharge

    Science.gov (United States)

    Barnwal, S.; Nigam, S.; Aneesh, K.; Prasad, Y. B. S. R.; Naik, P. A.; Navathe, C. P.; Gupta, P. D.

    2016-06-01

    The rate of rise in discharge current (d I/d t) is an important parameter in an X-ray laser pumped by fast capillary discharge. The effect of this parameter on the energy of an argon plasma-based 46.9-nm soft X-ray laser pulse has been experimentally studied. It was found that an X-ray laser pulse with ~2 μJ energy, which can be obtained at a discharge current of ~40 kA with d I/d t value of ~7.1 × 1011 A/s, can also be obtained at a much lower peak current of ~26 kA if the quarter period ( T/4) of the discharge current is made shorter to achieve a comparable d I/d t value. For a fixed T/4, the laser energy could be enhanced from 2 to 4 μJ for an increase in the d I/d t value from 7.1 × 1011 to 1.3 × 1012 A/s by increasing the peak current from 26 to 44 kA. It was also observed that for a fixed d I/d t, mere increase in the discharge current does not increase the laser energy.

  16. X-ray counterpart of gravitational waves due to binary neutron star mergers: light curves, luminosity functions, and event rate densities

    CERN Document Server

    Sun, Hui; Gao, He

    2016-01-01

    Zhang (2013) proposed a type of GRB-less X-ray transient associated with double neutron star (NS-NS) mergers under the conjecture of a rapidly-spinning magnetar merger product with the line of sight off the short GRB beam. We investigate possible light curves of these transients by considering different observer's viewing angles, including looking into a free zone where the emission due to direct dissipation of the magnetar wind is observable, and a trapped zone where X-rays are initially trapped by the ejecta launched during the merger, but later become transparent when the ejecta become optically thin. We perform Monte Carlo simulations to calculate the peak luminosity function (LF) and event rate density of these X-ray transients. By considering that a fraction of massive neutron stars may be supra-massive and collapse into black holes after a certain time, we investigate how the predicted luminosity functions depend on the equation of state (EoS) of the central object. In general, the luminosity functions...

  17. Handbook of X-Ray Data

    CERN Document Server

    Zschornack, Günter

    2007-01-01

    This sourcebook is intended as an X-ray data reference for scientists and engineers working in the field of energy or wavelength dispersive X-ray spectrometry and related fields of basic and applied research, technology, or process and quality controlling. In a concise and informative manner, the most important data connected with the emission of characteristic X-ray lines are tabulated for all elements up to Z = 95 (Americium). This includes X-ray energies, emission rates and widths as well as level characteristics such as binding energies, fluorescence yields, level widths and absorption edges. The tabulated data are characterized and, in most cases, evaluated. Furthermore, all important processes and phenomena connected with the production, emission and detection of characteristic X-rays are discussed. This reference book addresses all researchers and practitioners working with X-ray radiation and fills a gap in the available literature.

  18. Properties of water surface discharge at different pulse repetition rates

    Energy Technology Data Exchange (ETDEWEB)

    Ruma,; Yoshihara, K. [Graduate School of Science and Technology, Kumamoto University, Kumamoto 860-8555 (Japan); Hosseini, S. H. R., E-mail: hosseini@kumamoto-u.ac.jp; Sakugawa, T.; Akiyama, H. [Graduate School of Science and Technology, Kumamoto University, Kumamoto 860-8555 (Japan); Institute of Pulsed Power Science, Kumamoto University, Kumamoto 860-8555 (Japan); Akiyama, M. [Department of Electrical and Electronic Engineering, Kagoshima University, Kagoshima 890-0065 (Japan); Lukeš, P. [Institute of Plasma Physics, AS CR, Prague, Prague 18200 (Czech Republic)

    2014-09-28

    The properties of water surface discharge plasma for variety of pulse repetition rates are investigated. A magnetic pulse compression (MPC) pulsed power modulator able to deliver pulse repetition rates up to 1000 Hz, with 0.5 J per pulse energy output at 25 kV, was used as the pulsed power source. Positive pulse with a point-to-plane electrode configuration was used for the experiments. The concentration and production yield of hydrogen peroxide (H₂O₂) were quantitatively measured and orange II organic dye was treated, to evaluate the chemical properties of the discharge reactor. Experimental results show that the physical and chemical properties of water surface discharge are not influenced by pulse repetition rate, very different from those observed for under water discharge. The production yield of H₂O₂ and degradation rate per pulse of the dye did not significantly vary at different pulse repetition rates under a constant discharge mode on water surface. In addition, the solution temperature, pH, and conductivity for both water surface and underwater discharge reactors were measured to compare their plasma properties for different pulse repetition rates. The results confirm that surface discharge can be employed at high pulse repetition rates as a reliable and advantageous method for industrial and environmental decontamination applications.

  19. Breakdown behavior of electronics at variable pulse repetition rates

    OpenAIRE

    Korte, S.; H. Garbe

    2006-01-01

    The breakdown behavior of electronics exposed to single transient electromagnetic pulses is subject of investigations for several years. State-of-the-art pulse generators additionally provide the possibility to generate pulse sequences with variable pulse repetition rate. In this article the influence of this repetition rate variation on the breakdown behavior of electronic systems is described. For this purpose microcontroller systems are examined during line-led exposure to pulses with repe...

  20. Steady State Microbunching for High Brilliance and High Repetition Rate Storage Ring-Based Light Sources

    Energy Technology Data Exchange (ETDEWEB)

    Chao, Alex; Ratner, Daniel; /SLAC; Jiao, Yi; /Beijing, Inst. High Energy Phys.

    2012-09-06

    Electron-based light sources have proven to be effective sources of high brilliance, high frequency radiation. Such sources are typically either linac-Free Electron Laser (FEL) or storage ring types. The linac-FEL type has high brilliance (because the beam is microbunched) but low repetition rate. The storage ring type has high repetition rate (rapid beam circulation) but comparatively low brilliance or coherence. We propose to explore the feasibility of a microbunched beam in a storage ring that promises high repetition rate and high brilliance. The steady-state-micro-bunch (SSMB) beam in storage ring could provide CW sources for THz, EUV, or soft X-rays. Several SSMB mechanisms have been suggested recently, and in this report, we review a number of these SSMB concepts as promising directions for high brilliance, high repetition rate light sources of the future. The trick of SSMB lies in the RF system, together with the associated synchrotron beam dynamics, of the storage ring. Considering various different RF arrangements, there could be considered a number of scenarios of the SSMB. In this report, we arrange these scenarios more or less in order of the envisioned degree of technical challenge to the RF system, and not in the chronological order of their original references. Once the stored beam is steady-state microbunched in a storage ring, it passes through a radiator repeatedly every turn (or few turns). The radiator extracts a small fraction of the beam energy as coherent radiation with a wavelength corresponding to the microbunched period of the beam. In contrast to an FEL, this radiator is not needed to generate the microbunching (as required e.g. by SASE FELs or seeded FELs), so the radiator can be comparatively simple and short.

  1. Steady State Microbunching for High Brilliance and High Repetition Rate Storage Ring-Based Light Sources

    Energy Technology Data Exchange (ETDEWEB)

    Chao, Alex; Ratner, Daniel; /SLAC; Jiao, Yi; /Beijing, Inst. High Energy Phys.

    2012-09-06

    Electron-based light sources have proven to be effective sources of high brilliance, high frequency radiation. Such sources are typically either linac-Free Electron Laser (FEL) or storage ring types. The linac-FEL type has high brilliance (because the beam is microbunched) but low repetition rate. The storage ring type has high repetition rate (rapid beam circulation) but comparatively low brilliance or coherence. We propose to explore the feasibility of a microbunched beam in a storage ring that promises high repetition rate and high brilliance. The steady-state-micro-bunch (SSMB) beam in storage ring could provide CW sources for THz, EUV, or soft X-rays. Several SSMB mechanisms have been suggested recently, and in this report, we review a number of these SSMB concepts as promising directions for high brilliance, high repetition rate light sources of the future. The trick of SSMB lies in the RF system, together with the associated synchrotron beam dynamics, of the storage ring. Considering various different RF arrangements, there could be considered a number of scenarios of the SSMB. In this report, we arrange these scenarios more or less in order of the envisioned degree of technical challenge to the RF system, and not in the chronological order of their original references. Once the stored beam is steady-state microbunched in a storage ring, it passes through a radiator repeatedly every turn (or few turns). The radiator extracts a small fraction of the beam energy as coherent radiation with a wavelength corresponding to the microbunched period of the beam. In contrast to an FEL, this radiator is not needed to generate the microbunching (as required e.g. by SASE FELs or seeded FELs), so the radiator can be comparatively simple and short.

  2. X-ray crystallography

    Science.gov (United States)

    2001-01-01

    X-rays diffracted from a well-ordered protein crystal create sharp patterns of scattered light on film. A computer can use these patterns to generate a model of a protein molecule. To analyze the selected crystal, an X-ray crystallographer shines X-rays through the crystal. Unlike a single dental X-ray, which produces a shadow image of a tooth, these X-rays have to be taken many times from different angles to produce a pattern from the scattered light, a map of the intensity of the X-rays after they diffract through the crystal. The X-rays bounce off the electron clouds that form the outer structure of each atom. A flawed crystal will yield a blurry pattern; a well-ordered protein crystal yields a series of sharp diffraction patterns. From these patterns, researchers build an electron density map. With powerful computers and a lot of calculations, scientists can use the electron density patterns to determine the structure of the protein and make a computer-generated model of the structure. The models let researchers improve their understanding of how the protein functions. They also allow scientists to look for receptor sites and active areas that control a protein's function and role in the progress of diseases. From there, pharmaceutical researchers can design molecules that fit the active site, much like a key and lock, so that the protein is locked without affecting the rest of the body. This is called structure-based drug design.

  3. X-ray lasers

    CERN Document Server

    Elton, Raymond C

    2012-01-01

    The first in its field, this book is both an introduction to x-ray lasers and a how-to guide for specialists. It provides new entrants and others interested in the field with a comprehensive overview and describes useful examples of analysis and experiments as background and guidance for researchers undertaking new laser designs. In one succinct volume, X-Ray Lasers collects the knowledge and experience gained in two decades of x-ray laser development and conveys the exciting challenges and possibilities still to come._Add on for longer version of blurb_M>The reader is first introduced

  4. Measurement of Localized Corrosion Rates at Inclusion Particles in AA7075 by In Situ Three Dimensional (3D) X-ray Synchrotron Tomography

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Sudhanshu S.; Williams, Jason J.; Stannard, Tyler J.; Xiao, Xianghui; De Carlo, Francesco; Chawla, Nikhilesh

    2016-03-01

    In situ X-ray synchrotron tomography was used to measure the localized corrosion rate of Mg2Si particles present in 7075 aluminum alloys in deionized ultra-filtered (DIUF) water. The evolution of hydrogen bubbles was captured as a function of time and the measured volume was used to calculate the local corrosion rate of Mg2Si particles. It was shown that in the absence of chloride ions, stress was needed to create fresh particle surfaces, either by fracture or debonding, to initiate corrosion at the particles.

  5. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... Resources Professions Site Index A-Z X-ray (Radiography) - Bone Bone x-ray uses a very small ... X-ray (Radiography)? What is Bone X-ray (Radiography)? An x-ray (radiograph) is a noninvasive medical ...

  6. Implementation of ultrafast X-ray diffraction at the 1W2B wiggler beamline of Beijing Synchrotron Radiation Facility.

    Science.gov (United States)

    Sun, Da Rui; Xu, Guang Lei; Zhang, Bing Bing; Du, Xue Yan; Wang, Hao; Li, Qiu Ju; Zhou, Yang Fan; Li, Zhen Jie; Zhang, Yan; He, Jun; Yue, Jun Hui; Lei, Ge; Tao, Ye

    2016-05-01

    The implementation of a laser pump/X-ray probe scheme for performing picosecond-resolution X-ray diffraction at the 1W2B wiggler beamline at Beijing Synchrotron Radiation Facility is reported. With the hybrid fill pattern in top-up mode, a pixel array X-ray detector was optimized to gate out the signal from the singlet bunch with interval 85 ns from the bunch train. The singlet pulse intensity is ∼2.5 × 10(6) photons pulse(-1) at 10 keV. The laser pulse is synchronized to this singlet bunch at a 1 kHz repetition rate. A polycapillary X-ray lens was used for secondary focusing to obtain a 72 µm (FWHM) X-ray spot. Transient photo-induced strain in BiFeO3 film was observed at a ∼150 ps time resolution for demonstration.

  7. Time-resolved X-ray spectroscopies of chemical systems: New perspectives.

    Science.gov (United States)

    Chergui, Majed

    2016-05-01

    The past 3-5 years have witnessed a dramatic increase in the number of time-resolved X-ray spectroscopic studies, mainly driven by novel technical and methodological developments. The latter include (i) the high repetition rate optical pump/X-ray probe studies, which have greatly boosted the signal-to-noise ratio for picosecond (ps) X-ray absorption spectroscopy studies, while enabling ps X-ray emission spectroscopy (XES) at synchrotrons; (ii) the X-ray free electron lasers (XFELs) are a game changer and have allowed the first femtosecond (fs) XES and resonant inelastic X-ray scattering experiments to be carried out; (iii) XFELs are also opening the road to the development of non-linear X-ray methods. In this perspective, I will mainly focus on the most recent technical developments and briefly address some examples of scientific questions that have been addressed thanks to them. I will look at the novel opportunities in the horizon.

  8. Probing ultrafast dynamics of condensed matter with pump and probe experiments with X-rays

    Energy Technology Data Exchange (ETDEWEB)

    Giles, Carlos; Celestre, Rafael; Tasca, Kelin R.; Vescovi, Rafael; Faria, Guilherme; Dias, Carlos S.; Tomm, Natasha; Cordeiro, Cristiano M.B. [Universidade Estadual de Campinas (IFGW/UNICAMP), SP (Brazil). Inst. de Fisica Gleb Wataghin; Silva, Rene Nome [Universidade Estadual de Campinas (IQ/UNICAMP), SP (Brazil). Inst. de Quimica

    2012-07-01

    Full text: In this presentation we will describe recent advances in the route to start ultrafast studies with X-rays in Brazil. From one side pump and probe experiments using synchrotron radiation facilities will be described, showing how the thermal expansion of an invar alloy is not occurring at the picosecond time scales after heating the sample with a femtosecond infrared laser pulse. We will also describe the experimental setup at the LNLS in Campinas were we probe the fast response of a piezoelectric material to a 1 ns electric pulse recorded by a pump and probe X-ray diffraction experiment at the XRD2 LNLS beamline. We will also present the first results of the production of sub-picosecond X-ray pulses using an amplified infrared laser at the Ultrafast Laboratory of DEQ/IFGW. The instrumentation developed at UNICAMP together with the first setup for a pump and probe experiment will be presented. Characteristic radiation of various targets (TiK{alpha}, FeK{alpha}, CuK{alpha}) have been measured at a repetition rate of 1 kHz showing unambiguously our capability of producing a pulsed X-ray source for time resolved x-ray diffraction experiments. Experiments to measure the pulse width of the X-ray radiation are under development and the latest results will be presented. All these efforts open the path to the nucleation of a research group in ultrafast studies using X-rays in Brazil. (author)

  9. Bone x-ray

    Science.gov (United States)

    ... or broken bone Bone tumors Degenerative bone conditions Osteomyelitis (inflammation of the bone caused by an infection) ... Multiple myeloma Osgood-Schlatter disease Osteogenesis imperfecta Osteomalacia Osteomyelitis Paget disease of the bone Rickets X-ray ...

  10. Hand x-ray

    Science.gov (United States)

    ... include fractures, bone tumors , degenerative bone conditions, and osteomyelitis (inflammation of the bone caused by an infection). ... chap 46. Read More Bone tumor Broken bone Osteomyelitis X-ray Review Date 9/8/2014 Updated ...

  11. Pelvis x-ray

    Science.gov (United States)

    X-ray - pelvis ... Tumors Degenerative conditions of bones in the hips, pelvis, and upper legs ... hip joint Tumors of the bones of the pelvis Sacroiliitis (inflammation of the area where the sacrum ...

  12. Chest X-Ray

    Medline Plus

    Full Text Available ... and use a very small dose of ionizing radiation to produce pictures of the inside of the ... x-ray use a tiny dose of ionizing radiation, the benefit of an accurate diagnosis far outweighs ...

  13. Chest X-Ray

    Medline Plus

    Full Text Available ... Index A-Z Spotlight October is National Breast Cancer Awareness Month Recently posted: Medical Imaging Costs Magnetoencephalography ( ... of lung conditions such as pneumonia, emphysema and cancer. A chest x-ray requires no special preparation. ...

  14. Chest X-Ray

    Medline Plus

    Full Text Available ... chest x-ray is used to evaluate the lungs, heart and chest wall and may be used ... diagnose and monitor treatment for a variety of lung conditions such as pneumonia, emphysema and cancer. A ...

  15. X-ray - skeleton

    Science.gov (United States)

    ... x-ray particles pass through the body. A computer or special film records the images. Structures that ... M. is also a founding member of Hi-Ethics and subscribes to the principles of the Health ...

  16. X-Ray Diffraction.

    Science.gov (United States)

    Smith, D. K.; Smith, K. L.

    1980-01-01

    Reviews applications in research and analytical characterization of compounds and materials in the field of X-ray diffraction, emphasizing new developments in applications and instrumentation in both single crystal and powder diffraction. Cites 414 references. (CS)

  17. Chest X-Ray

    Medline Plus

    Full Text Available ... breath, persistent cough, fever, chest pain or injury. It may also be useful to help diagnose and ... have some concerns about chest x-rays. However, it’s important to consider the likelihood of benefit to ...

  18. X-Ray Diffraction.

    Science.gov (United States)

    Smith, D. K.; Smith, K. L.

    1980-01-01

    Reviews applications in research and analytical characterization of compounds and materials in the field of X-ray diffraction, emphasizing new developments in applications and instrumentation in both single crystal and powder diffraction. Cites 414 references. (CS)

  19. Chest X-Ray

    Medline Plus

    Full Text Available ... breath, persistent cough, fever, chest pain or injury. It may also be useful to help diagnose and ... have some concerns about chest x-rays. However, it’s important to consider the likelihood of benefit to ...

  20. Chest X-Ray

    Medline Plus

    Full Text Available ... CT Angiography Video: Myelography Video: CT of the Heart Video: Radioiodine I-131 Therapy Radiology and You ... x-ray is used to evaluate the lungs, heart and chest wall and may be used to ...

  1. Symbiotic Stars in X-rays

    Science.gov (United States)

    Luna, G. J. M.; Sokoloski, J. L.; Mukai, K.; Nelson, T.

    2014-01-01

    hard X-ray emission from the innermost accretion region. Since we have identified the elusive accretion component in the emission from a sample of symbiotic stars, our results have implications for the understanding of wind-fed mass transfer in wide binaries, and the accretion rate in one class of candidate progenitors of type Ia supernovae.

  2. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... holds the x-ray film or image recording plate . Sometimes the x-ray is taken with the ... an x-ray film holder or image recording plate is placed beneath the patient. top of page ...

  3. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... the limitations of Bone X-ray (Radiography)? What is Bone X-ray (Radiography)? An x-ray (radiograph) ... diagnosis and disease management. top of page How is the procedure performed? The technologist, an individual specially ...

  4. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... holds the x-ray film or image recording plate . Sometimes the x-ray is taken with the ... an x-ray film holder or image recording plate is placed beneath the patient. top of page ...

  5. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... drawer under the table holds the x-ray film or image recording plate . Sometimes the x-ray ... extended over the patient while an x-ray film holder or image recording plate is placed beneath ...

  6. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... that might interfere with the x-ray images. Women should always inform their physician and x-ray ... Safety page for more information about radiation dose. Women should always inform their physician or x-ray ...

  7. 1  J, 0.5  kHz repetition rate picosecond laser.

    Science.gov (United States)

    Baumgarten, Cory; Pedicone, Michael; Bravo, Herman; Wang, Hanchen; Yin, Liang; Menoni, Carmen S; Rocca, Jorge J; Reagan, Brendan A

    2016-07-15

    We report the demonstration of a diode-pumped chirped pulse amplification Yb:YAG laser that produces λ=1.03  μm pulses of up to 1.5 J energy compressible to sub-5 ps duration at a repetition rate of 500 Hz (750 W average power). Amplification to high energy takes place in cryogenically cooled Yb:YAG active mirrors designed for kilowatt average power laser operation. This compact laser system will enable new advances in high-average-power ultrashort-pulse lasers and high-repetition-rate tabletop soft x-ray lasers. As a first application, the laser was used to pump a 400 Hz λ=18.9  nm laser.

  8. kHz femtosecond laser-plasma hard X-ray and fast ion source

    Science.gov (United States)

    Thoss, A.; Korn, G.; Richardson, M. C.; Faubel, M.; Stiel, H.; Voigt, U.; Siders, C. W.; Elsaesser, T.

    2002-04-01

    We describe the first demonstration of a new stable, kHz femtosecond laser-plasma source of hard x-ray continuum and Kα emission using a thin liquid metallic jet target. kHz femtosecond x-ray sources will find many applications in time-resolved x-ray diffraction and microscopy studies. As high intensity lasers become more compact and operate at increasingly high repetition-rates, they require a target configuration that is both repeatable from shot-to-shot and is debris-free. We have solved this requirement with the use of a fine (10-30 μm diameter) liquid metal jet target that provides a pristine, unperturbed filament surface at rates >100 kHz. A number of liquid metal targets are considered. We will show hard x-ray spectra recorded from liquid Ga targets that show the generation of the 9.3 keV and 10.3 keV, Kα and Kβ lines superimposed on a multi-keV Bremsstrahlung continuum. This source was generated by a 50fs duration, 1 kHz, 2W, high intensity Ti:Sapphire laser. We will discuss the extension of this source to higher powers and higher repetition rates, providing harder x-ray emission, with the incorporation of pulse-shaping and other techniques to enhance the x-ray conversion efficiency. Using the same liquid target technology, we have also demonstrated the generation of forward-going sub-MeV protons from a 10 μm liquid water target at 1 kHz repetition rates. kHz sources of high energy ions will find many applications in time-resolved particle interaction studies, as well as lead to the efficient generation of short-lived isotopes for use in nuclear medicine and other applications. The protons were detected with CR-39 track detectors both in the forward and backward directions up to energies of ~500 keV. As the intensity of compact high repetition-rate lasers sources increase, we can expect improvements in the energy, conversion efficiency and directionality to occur. The impact of these developments on a number of fields will be discussed. As compact

  9. 12th International Conference on X-Ray Lasers

    CERN Document Server

    Nam, Chang; Janulewicz, Karol

    2011-01-01

    This book provides a comprehensive review of the present status of achievements in the area of soft X-ray laser sources, supplemented by information about sources based on relativistic laser˗matter interaction and their future, and incoherent sources within a very broad spectral range. The diversity of demonstrated or planned applications presented in the book supports the thesis that such sources have now reached a mature stage of development. There is a significant effort worldwide to develop very bright, ultra-short duration, radiation sources in the extreme ultraviolet and X-ray spectral regions, driven by a diversity of potential applications in nearly all branches of science. This book updates the status in this field and focuses on developments in laser plasma-based methods. The scheme of transient inversion proves its robustness by being dominant in the area of repetitive X-ray lasers pumped at grazing-incidence-geometry by optical lasers of moderate energy at increasing repetition rates – these ch...

  10. Diagnostic for a high-repetition rate electron photo-gun and first measurements

    Science.gov (United States)

    Filippetto, D.; Doolittle, L.; Huang, G.; Norum, E.; Portmann, G.; Qian, H.; Sannibale, F.

    2015-05-01

    The APEX electron source at LBNL combines the high-repetition-rate with the high beam brightness typical of photoguns, delivering low emittance electron pulses at MHz frequency. Proving the high beam quality of the beam is an essential step for the success of the experiment, opening the doors of the high average power to brightness-hungry applications as X-Ray FELs, MHz ultrafast electron diffraction etc.. As first step, a complete characterization of the beam parameters is foreseen at the Gun beam energy of 750 keV. Diagnostics for low and high current measurements have been installed and tested, and measurements of cathode lifetime and thermal emittance in a RF environment with mA current performed. The recent installation of a double slit system, a deflecting cavity and a high precision spectrometer, allow the exploration of the full 6D phase space. Here we discuss the present layout of the machine and future upgrades, showing the latest results at low and high repetition rate, together with the tools and techniques used.

  11. Wavelengths, oscillator strengths and radiative transition rates for K{alpha} lines in titanium x-ray spectra

    Energy Technology Data Exchange (ETDEWEB)

    Hu Feng; Wang Chuangke; Zhao Xuefeng [Research Center of Laser Fusion, China Academy of Engineering Physics, Mianyang 621900 (China); Yang Jiamin; Jiang Gang, E-mail: yjm70018@my-public.sc.cninfo.net [Institute of Atomic and Molecular Physics, Sichuan University, Chengdu 610064 (China)

    2011-06-15

    The oscillator strengths, line strengths and wavelengths are presented for all 1s-2p transitions in titanium ions. X-ray emission from titanium is extensively used, for example for diagnosis, in fusion experiments. The K{alpha} 1s-2p transitions are limited to transitions from helium-like to fluorine-like ion as the 2p subshell is filled beyond fluorine. While there are two 1s-2p transitions (1s{sup 2}S{sub 1/2}-2p{sup 2}P{sub 1/2} and 1s{sup 2}S{sub 1/2}-2p{sup 2}P{sub 3/2}) for hydrogen-like titanium, Ti{sup 20+}, the number varies depending on the number of electrons in the 2p subshell before and after the transition. For example, there are 35 1s-2p transitions giving the same number of K{alpha} lines for carbon-like titanium, Ti{sup 16+}. The present results are obtained from configuration interaction atomic structure calculations using the code GRASPVU, which includes relativistic effects in the Dirac-Fock approximation. The results have been benchmarked for a few ionic states. A comparison of our results with the very few transitions in the literature as well as those from other codes shows reasonable accuracy of the present results.

  12. Uniaxial Compression of Cellular Materials at a 10-1 s-1 Strain Rate Simultaneously with Synchrotron X-ray Computed Tomographic Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Patterson, Brian M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-03-01

    The topic is presented as a series of slides. Motivation for the work included the following: X-ray tomography is a fantastic technique for characterizing a material’s starting structure as well as for non-destructive, in situ experiments to investigate material response; 3D X-ray tomography is needed to fully characterize the morphology of cellular materials; and synchrotron micro-CT can capture 3D images without pausing experiment. Among the conclusions reached are these: High-rate radiographic and tomographic imaging (0.25 s 3D frame rate) using synchrotron CT can capture full 3D images of hyper-elastic materials at a 10-2 strain rate; dynamic true in situ uniaxial loading can be accurately captured; the three stages of compression can be imaged: bending, buckling, and breaking; implementation of linear modeling is completed; meshes have been imported into LANL modeling codes--testing and validation is underway and direct comparison and validation between in situ data and modeled mechanical response is possible.

  13. Experimental measurements of the O15(alpha,gamma)Ne19 reaction rate vs. observations of type I X-ray bursts

    CERN Document Server

    Fisker, J L; Görres, J; Wiescher, M; Cooper, R L; Fisker, Jacob Lund; Tan, Wanpeng; Goerres, Joachim; Wiescher, Michael; Cooper, Randall L.

    2007-01-01

    Neutron stars in close binary star systems often accrete matter from their companion stars. Thermonuclear ignition of the accreted material in the atmosphere of the neutron star leads to a thermonuclear explosion which is observed as an X-ray burst occurring periodically between hours and days depending on the accretion rate. The ignition conditions are characterized by a sensitive interplay between the continuously accreting fuel supply and depletion by nuclear burning via the hot CNO cycles. Therefore the ignition depends critically on the hot CNO breakout reaction O15(alpha,gamma)Ne19 that regulates the flow between the beta-limited hot CNO cycle and the rapid proton capture process. Until recently, the O15(alpha,gamma)Ne19 reaction rate was not known experimentally and the theoretical estimates carried significant uncertainties. In this paper we report on the astrophysical consequences of the first measurement of this reaction rate on the thermonuclear instability that leads to type I X-ray bursts on accr...

  14. The BESSY Soft X-Ray FEL User Facility

    CERN Document Server

    Kraemer, Dieter

    2005-01-01

    The user requests for an optimized 2nd generation FEL facility in the VUV to soft X-ray range demand for ultra short photon pulses (t = 20 fs) at a peak power of several GW. A high shot to shot reproducibility of the pulse shape and pulse power allowing for fs-synchronization for pump-probe experiments is feasible in a seeded FEL approach. Free selectable photon polarization and wavelength tuning is essential for any 2nd generation FEL source like the proposed BESSY-Soft X-ray FEL user facility. Freely selectable pulse repetition rates and freely selectable pulse patterns, including fast switching to different parallel operating FEL-Lines are necessary ingredients, feasible with a suitable injector in combination with a CW-superconducting linac. The status of the BESSY HGHG-FEL project will be reviewed.

  15. High duty cycle inverse Compton scattering X-ray source

    Science.gov (United States)

    Ovodenko, A.; Agustsson, R.; Babzien, M.; Campese, T.; Fedurin, M.; Murokh, A.; Pogorelsky, I.; Polyanskiy, M.; Rosenzweig, J.; Sakai, Y.; Shaftan, T.; Swinson, C.

    2016-12-01

    Inverse Compton Scattering (ICS) is an emerging compact X-ray source technology, where the small source size and high spectral brightness are of interest for multitude of applications. However, to satisfy the practical flux requirements, a high-repetition-rate ICS system needs to be developed. To this end, this paper reports the experimental demonstration of a high peak brightness ICS source operating in a burst mode at 40 MHz. A pulse train interaction has been achieved by recirculating a picosecond CO2 laser pulse inside an active optical cavity synchronized to the electron beam. The pulse train ICS performance has been characterized at 5- and 15- pulses per train and compared to a single pulse operation under the same operating conditions. With the observed near-linear X-ray photon yield gain due to recirculation, as well as noticeably higher operational reliability, the burst-mode ICS offers a great potential for practical scalability towards high duty cycles.

  16. ROBUST REPETITIVE CONTROL FOR IMPROVING RATE SMOOTHNESS OF TEST TURNTABLE

    Institute of Scientific and Technical Information of China (English)

    LIUYu; ZENGMing; SUBao-ku

    2005-01-01

    A robust repetitive control scheme is used to improve the rate smoothness of a brushless DC motor (BLDCM) driven test turntable. The method synthesizes variable structure control (VSC) laws and repetitive control (RC) laws in a complementary manner. The VSC strategy can stabilize the system and suppress uncertainties, such as the aperiodic disturbance and noises, while RC strategy can eliminate the periodic rate fluctuation in a steady state. The convergence of the repetitive learning process is also guaranteed by VSC. A general nonlinear system model is discussed. The model can be considered as an extension of BLDCMs. The stability and asymptotic position tracking performance are validated by using Lyapunov functions. Simulation results show the effectiveness of the proposed approach for improving the rate smoothness.

  17. X-Ray Absorption with Transmission X-Ray Microscopes

    NARCIS (Netherlands)

    de Groot, F.M.F.

    2016-01-01

    In this section we focus on the use of transmission X-ray microscopy (TXM) to measure the XAS spectra. In the last decade a range of soft X-ray and hard X-ray TXM microscopes have been developed, allowing the measurement of XAS spectra with 10–100 nm resolution. In the hard X-ray range the TXM

  18. Application of x-ray sensors for in-line and non-invasive monitoring of mass flow rate in continuous tablet manufacturing.

    Science.gov (United States)

    Ganesh, Sudarshan; Troscinski, Rachel; Schmall, Nicholas; Lim, Jongmook; Nagy, Zoltan; Reklaitis, Gintaras

    2017-08-31

    The progress in continuous downstream manufacturing of oral solid doses demands effective real-time process management, with monitoring at its core. This study evaluates the feasibility of using a commercial sensor to measure the mass flow rate of the particulates, a critical process variable in continuous manufacturing. The sensor independently measures x-ray attenuation and cross-correlation velocimetry of particulate flow in real-time. Steady-state flow rates of blends comprised primarily of acetaminophen and microcrystalline-cellulose are monitored using the sensor, with simultaneous weighing scale measurements, in order to calibrate the sensor and investigate the measurement accuracy. The free-fall flow measurement of the powder and granule blends in a conduit is linearly proportional to the x-ray attenuation. Relative standard deviations (RSD) of ∼3-7% for 1 second monitoring are observed and a measurement error of approximately 5% suggest the usability of the sensor for real-time monitoring. The sensor measurement is robust for operational variations in composition, addition of lubricant or glidant and reuse of material for PAT tool calibration. The measurement RSD depends on particulate flow dynamics at the sensor location. This requires experimental evaluation for a given material at the sensor location, in order to capture the flow dynamics of the particulate stream through the sensor. Copyright © 2017. Published by Elsevier Inc.

  19. A complementary dual-slope ADC with high frame rate and wide input range for fast X-ray imaging

    Science.gov (United States)

    Lee, Daehee; Cho, Minsik; Kang, Dong-Uk; Kim, Myung Soo; Kim, Hyunduk; Cho, Gyuseong

    2014-02-01

    The single-slope analog-to-digital converter (SS-ADC) is the most commonly used column-level ADC for high-speed industrial, complementary metal-oxide semiconductor (CMOS)-based X-ray image sensors because of its small chip area (the width of a pixel), its simple circuit structure, and its low power consumption. However, it generally has a long conversion time, so we propose an innovative design: a complimentary dual-slope ADC (CDS-ADC) that uses two opposite ramp signals instead of a single ramp to double the conversion speed. This CDS-ADC occupies only 15% more area than the original SS-ADC. A prototype 12-bit CDS-ADC and a 12-bit SS-ADC were fabricated using a 0.35-µm 1P 4M CMOS process. During comparison of the two, the measured maximum differential non-linearity (DNL) of the CDS-ADC was a 0.49 least significant bit (LSB), the maximum integral non-linearity (INL) was a 0.43 LSB, the effective number of bits (ENOB) was 9.18 bits, and the figure of merit (FOM) was 0.03 pJ/conversion. The total power consumption was 0.031 uW. The conversion time of the new CDS-ADC was half that of the SS-ADC. The proposed dual-slope concept can be extended to further multiply the conversion speed by using multiple pairs of dual-slope ramps.

  20. Demonstration of a high repetition rate capillary discharge waveguide

    Energy Technology Data Exchange (ETDEWEB)

    Gonsalves, A. J., E-mail: ajgonsalves@lbl.gov; Pieronek, C.; Daniels, J.; Bulanov, S. S.; Waldron, W. L.; Mittelberger, D. E.; Leemans, W. P. [Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Liu, F.; Antipov, S.; Butler, J. E. [Euclid TechLabs, Gaithersburg, Maryland 20879 (United States); Bobrova, N. A.; Sasorov, P. V. [Keldysh Institute of Applied Mathematics, Moscow (Russian Federation)

    2016-01-21

    A hydrogen-filled capillary discharge waveguide operating at kHz repetition rates is presented for parameters relevant to laser plasma acceleration (LPA). The discharge current pulse was optimized for erosion mitigation with laser guiding experiments and MHD simulation. Heat flow simulations and measurements showed modest temperature rise at the capillary wall due to the average heat load at kHz repetition rates with water-cooled capillaries, which is promising for applications of LPAs such as high average power radiation sources.

  1. X-rays, clumping and wind structures

    Science.gov (United States)

    Oskinova, Lidia; Hamann, Wolf-Rainer; Ignace, Richard; Feldmeier, Achim

    2011-01-01

    X-ray emission is ubiquitous among massive stars. In the last decade, X-ray observations revolutionized our perception of stellar winds but opened a Pandora's box of urgent problems. X-rays penetrating stellar winds suffer mainly continuum absorption, which greatly simplifies the radiative transfer treatment. The small and large scale structures in stellar winds must be accounted for to understand the X-ray emission from massive stars. The analysis of X-ray spectral lines can help to infer the parameters of wind clumping, which is prerequisite for obtaining empirically correct stellar mass-loss rates. The imprint of large scale structures, such as CIRs and equatorial disks, on the X-ray emission is predicted, and new observations are testing theoretical expectations. The X-ray emission from magnetic stars proves to be more diverse than anticipated from the direct application of the magnetically-confined wind model. Many outstanding questions about X-rays from massive stars will be answered when the models and the observations advance.

  2. Single-pass high harmonic generation at high repetition rate and photon flux

    Science.gov (United States)

    Hädrich, Steffen; Rothhardt, Jan; Krebs, Manuel; Demmler, Stefan; Klenke, Arno; Tünnermann, Andreas; Limpert, Jens

    2016-09-01

    Sources of short wavelength radiation with femtosecond to attosecond pulse durations, such as synchrotrons or free electron lasers, have already made possible numerous, and will facilitate more, seminal studies aimed at understanding atomic and molecular processes on fundamental length and time scales. Table-top sources of coherent extreme ultraviolet to soft x-ray radiation enabled by high harmonic generation (HHG) of ultrashort pulse lasers have also gained significant attention in the last few years due to their enormous potential for addressing a plethora of applications, therefore constituting a complementary source to large-scale facilities (synchrotrons and free electron lasers). Ti:sapphire based laser systems have been the workhorses for HHG for decades, but are limited in repetition rate and average power. On the other hand, it has been widely recognized that fostering applications in fields such as photoelectron spectroscopy and microscopy, coincidence detection, coherent diffractive imaging and frequency metrology requires a high repetition rate and high photon flux HHG sources. In this article we will review recent developments in realizing the demanding requirement of producing a high photon flux and repetition rate at the same time. Particular emphasis will be put on suitable ultrashort pulse and high average power lasers, which directly drive harmonic generation without the need for external enhancement cavities. To this end we describe two complementary schemes that have been successfully employed for high power fiber lasers, i.e. optical parametric chirped pulse amplifiers and nonlinear pulse compression. Moreover, the issue of phase-matching in tight focusing geometries will be discussed and connected to recent experiments. We will highlight the latest results in fiber laser driven high harmonic generation that currently produce the highest photon flux of all existing sources. In addition, we demonstrate the first promising applications and

  3. X-Ray Protection

    Science.gov (United States)

    1955-01-01

    15,000. • When developed In Kodak liquid X-ray developer for 5 min at a temperature of 200 C. b Film sensitivities vary with photon energy by the...for example temporomandibular -joint exposures where a skin dose of 25 r or more may be obtained during a single exposure with 65 kvp, 1.5 mm aluminum...communication. W. J. Updegrave, Temporomandibular articulation-X-ray examina- tion, Dental Radiography and Photography 26, No. 3, 41 (1953). H. 0. Wyckoff, R. J

  4. X-ray Reflection

    Science.gov (United States)

    Fabian, A. C.; Ross, R. R.

    2010-12-01

    Material irradiated by X-rays produces backscattered radiation which is commonly known as the Reflection Spectrum. It consists of a structured continuum, due at high energies to the competition between photoelectric absorption and electron scattering enhanced at low energies by emission from the material itself, together with a complex line spectrum. We briefly review the history of X-ray reflection in astronomy and discuss various methods for computing the reflection spectrum from cold and ionized gas, illustrated with results from our own work reflionx. We discuss how the reflection spectrum can be used to obtain the geometry of the accretion flow, particularly the inner regions around black holes and neutron stars.

  5. Panoramic Dental X-Ray

    Science.gov (United States)

    ... Physician Resources Professions Site Index A-Z Panoramic Dental X-ray Panoramic dental x-ray uses a very small dose of ... x-ray , is a two-dimensional (2-D) dental x-ray examination that captures the entire mouth ...

  6. Non-destructive Prediction of Enteric Coating Layer Thickness and Drug Dissolution Rate by Near-infrared spectroscopy and X-ray computed tomography.

    Science.gov (United States)

    Ariyasu, Aoi; Hattori, Yusuke; Otsuka, Makoto

    2017-04-07

    The coating layer thickness of enteric-coated tablets is a key factor that determines the drug dissolution rate from the tablet. Near-infrared spectroscopy (NIRS) enables non-destructive and quick measurement of the coating layer thickness, and thus allows the investigation of the relation between enteric coating layer thickness and drug dissolution rate. Two marketed products of aspirin enteric-coated tablets were used in this study, and the correlation between the predicted coating layer thickness and the obtained drug dissolution rate was investigated. Our results showed correlation for one product; the drug dissolution rate decreased with the increase in enteric coating layer thickness, whereas, there was no correlation for the other product. Additional examination of the distribution of coating layer thickness by X-ray computed tomography (CT) showed homogenous distribution of coating layer thickness for the former product, whereas the latter product exhibited heterogeneous distribution within the tablet, as well as inconsistent trend in the distribution between the tablets. It was suggested that this heterogeneity and inconsistent trend in layer thickness distribution contributed to the absence of correlation between the layer thickness of the face and side regions of the tablets, which resulted in the loss of correlation between the coating layer thickness and drug dissolution rate. Therefore, the predictability of drug dissolution rate from enteric-coated tablets depended on the homogeneity of the coating layer thickness. In addition, the importance of micro analysis, X-ray CT in this study, was suggested even if the macro analysis, NIR spectroscopy (NIRS) in this study, are finally applied for the measurement.

  7. Visualization and quantification of heterogeneous diffusion rates in granodiorite samples by X-ray absorption imaging. Diffusion within gouge materials, altered rim and intact rock matrix

    Energy Technology Data Exchange (ETDEWEB)

    Altman, S.J.; Tidwell, V.C. [Sandia National Laboratories, Albuquerque, NM (United States); Uchida, M. [Japan Nuclear Cycle Development Inst., Ibaraki (Japan)

    2001-08-01

    Matrix diffusion is one of the most important contaminant migration retardation processes in crystalline rocks. Performance assessment calculations in various countries assume that only the area of the fracture surface where advection is active provides access to the rock matrix. However, accessibility to the matrix could be significantly enhanced with diffusion into stagnant zones, fracture fillings, and through an alteration rim in the matrix. Laboratory visualization experiments were conducted on granodiorite samples to investigate and quantify diffusion rates within different zones of a Cretaceous granodiorite. Samples were collected from the Kamaishi experimental site in the northern part of the main island of Japan. Diffusion of iodine out of the sample is visualized and rates are measured using x-ray absorption imaging. X-ray images allow for measurements of relative iodine concentration and relative iodine mass as a function of time and two-dimensional space at a sub-millimeter spatial resolution. In addition, two-dimensional heterogeneous porosity fields (at the same resolution as the relative concentration fields) are measured. This imaging technique allows for a greater understanding of the spatial variability of diffusion rates than can be accomplished with standard bulk measurements. It was found that diffusion rates were fastest in partially gouge-filled fractures. Diffusion rates in the recrystallized calcite-based fracture-filling material were up to an order of magnitude lower than in gouge-filled fractures. Diffusion in altered matrix around the fractures was over an order of magnitude lower than that in the gouge-filled fractures. Healed fractures did not appear to have different diffusion rates than the unaltered matrix.

  8. Medium Repetition Rate TEA Laser For Industrial Applications

    Science.gov (United States)

    Walter, Bruno

    1987-09-01

    The design and performance of an inexpensive compact repetitively pulsed TEA CO2 laser is described. The device uses a modified corona preionization technique and a fast transverse gas flow to achieve high repetition rates. An output energy of 500 mJ per pulse and an out-put power of 6.2W at 40Hz have been obtained. Due to the small energy needed for preionization, the efficiency of the device is high, whereas the gas dissociation is low when compared with commercial laser systems. This results in the relatively small fresh laser gas exchange of 20 ltr h-1 for long term operation.

  9. Intensity interferometry of single x-ray pulses from a synchrotron storage ring

    CERN Document Server

    Singer, A; Marras, A; Klyuev, A; Becker, J; Schlage, K; Skopintsev, P; Gorobtsov, O; Shabalin, A; Wille, H -C; Franz, H; Graafsma, H; Vartanyants, I A

    2014-01-01

    We report on measurements of second-order intensity correlations at the high brilliance storage ring PETRA III using a prototype of the newly developed Adaptive Gain Integrating Pixel Detector (AGIPD). The detector recorded individual synchrotron radiation pulses with an x-ray photon energy of 14.4 keV and repetition rate of about 5 MHz. The second-order intensity correlation function was measured simultaneously at different spatial separations that allowed to determine the transverse coherence length at these x-ray energies. The measured values are in a good agreement with theoretical simulations based on the Gaussian Schell-model.

  10. Chest X-Ray

    Medline Plus

    Full Text Available ... Therapy November 8 is the International Day of Radiology (IDoR) Radiology and You Sponsored by Image/Video Gallery Your Radiologist Explains Chest X-ray Transcript Welcome to Radiology Info dot org! Hello, I’m Dr. Geoffrey ...

  11. A Particle X-ray Temporal Diagnostic (PXTD) for studies of kinetic, multi-ion effects, and ion-electron equilibration rates in Inertial Confinement Fusion plasmas at OMEGA (invited)

    Energy Technology Data Exchange (ETDEWEB)

    Sio, H. [Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA; Frenje, J. A. [Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA; Katz, J. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623, USA; Stoeckl, C. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623, USA; Weiner, D. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623, USA; Bedzyk, M. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623, USA; Glebov, V. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623, USA; Sorce, C. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623, USA; Gatu Johnson, M. [Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA; Rinderknecht, H. G. [Lawrence Livermore National Laboratory, Livermore, California 94550, USA; Zylstra, A. B. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA; Sangster, T. C. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623, USA; Regan, S. P. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623, USA; Kwan, T. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA; Le, A. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA; Simakov, A. N. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA; Taitano, W. T. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA; Chacòn, L. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA; Keenan, B. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA; Shah, R. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA; Sutcliffe, G. [Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA; Petrasso, R. D. [Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA

    2016-09-14

    A Particle X-ray Temporal Diagnostic (PXTD) has been implemented on OMEGA for simultaneous time-resolved measurements of several nuclear products as well as the x-ray continuum produced in High Energy Density Plasmas and Inertial Confinement Fusion implosions. The PXTD removes systematic timing uncertainties typically introduced by using multiple instruments, and it has been used to measure DD, DT, D3He, and T3He reaction histories and the emission history of the x-ray core continuum with relative timing uncertainties within ±10-20 ps. This enables, for the first time, accurate and simultaneous measurements of the x-ray emission histories, nuclear reaction histories, their time differences, and measurements of Ti(t) and Te(t) from which an assessment of multiple-ion-fluid effects, kinetic effects during the shock-burn phase, and ion-electron equilibration rates can be made.

  12. A Particle X-ray Temporal Diagnostic (PXTD) for studies of kinetic, multi-ion effects, and ion-electron equilibration rates in Inertial Confinement Fusion plasmas at OMEGA (invited)

    Science.gov (United States)

    Sio, H.; Frenje, J. A.; Katz, J.; Stoeckl, C.; Weiner, D.; Bedzyk, M.; Glebov, V.; Sorce, C.; Gatu Johnson, M.; Rinderknecht, H. G.; Zylstra, A. B.; Sangster, T. C.; Regan, S. P.; Kwan, T.; Le, A.; Simakov, A. N.; Taitano, W. T.; Chacòn, L.; Keenan, B.; Shah, R.; Sutcliffe, G.; Petrasso, R. D.

    2016-11-01

    A Particle X-ray Temporal Diagnostic (PXTD) has been implemented on OMEGA for simultaneous time-resolved measurements of several nuclear products as well as the x-ray continuum produced in High Energy Density Plasmas and Inertial Confinement Fusion implosions. The PXTD removes systematic timing uncertainties typically introduced by using multiple instruments, and it has been used to measure DD, DT, D3He, and T3He reaction histories and the emission history of the x-ray core continuum with relative timing uncertainties within ±10-20 ps. This enables, for the first time, accurate and simultaneous measurements of the x-ray emission histories, nuclear reaction histories, their time differences, and measurements of Ti(t) and Te(t) from which an assessment of multiple-ion-fluid effects, kinetic effects during the shock-burn phase, and ion-electron equilibration rates can be made.

  13. Sub-Picosecond Tunable Hard X-Ray Undulator Source for Laser/X-Ray Pump-Probe Experiments

    Science.gov (United States)

    Ingold, G.; Beaud, P.; Johnson, S.; Streun, A.; Schmidt, T.; Abela, R.; Al-Adwan, A.; Abramsohn, D.; Böge, M.; Grolimund, D.; Keller, A.; Krasniqi, F.; Rivkin, L.; Rohrer, M.; Schilcher, T.; Schmidt, T.; Schlott, V.; Schulz, L.; van der Veen, F.; Zimoch, D.

    2007-01-01

    The FEMTO source under construction at the μXAS beamline is designed to enable tunable time-resolved laser/x-ray absorption and diffraction experiments in photochemistry and condensed matter with ps- and sub-ps resolution. The design takes advantage of (1) the highly stable operation of the SLS storage ring, (2) the reliable high harmonic operation of small gap, short period undulators to generate hard x-rays with energy 3-18 keV at 2.4 GeV beam energy, and (3) the progress in high power, high repetition rate fs solid-state laser technology to employ laser/e-beam `slicing' to reach a time resolution of ultimately 100 fs. The source will profit from the inherently synchronized pump (laser I: 100 fs, 2 mJ, 1 kHz) and probe (sliced X-rays, laser II: 50 fs, 5 mJ, 1 kHz) pulses, and from the excellent stability of the SLS storage ring which is operated in top-up mode and controlled by a fast orbit feedback (FOFB). Coherent radiation emitted at THz frequencies by the sliced 100 fs electron bunches will be monitored as on-line cross-correlation signal to keep the laser-electron beam interaction at optimum. The source is designed to provide at 8 keV (100 fs) a monochromized flux of 104 ph/s/0.01% bw (Si crystal monochromator) and 106 ph/s/1.5% bw (multilayer monochromator) at the sample. It is operated in parasitic mode using a hybrid bunch filling pattern. Because of the low intensity measurements are carried out repetitively over many shots using refreshing samples and gated detectors. `Diffraction gating' experiments will be used to characterize the sub-ps X-ray pulses.

  14. Experimental study of conversion from atomic high-order harmonics to x-ray emissions

    Institute of Scientific and Technical Information of China (English)

    王骐; 陈建新; 夏元钦; 陈德应

    2003-01-01

    There are two physical phenomena in a strong laser intensity. One is the high-order harmonic emission; the other is x-ray emission from optical-field ionized plasmas. The experiment of conversion from high-order harmonics to x-ray emissions was given with a 105fs Ti:sapphire laser by adjusting laser intensities. The ingredient in plasma was investigated by the numerical simulations. Our experimental results suggested that the free electrons have detrimental effects on harmonic generation but are favourable for x-ray emission from optical-field ionized plasmas. If we want to obtain more intense harmonic signals as a coherent light source in the soft x-ray region, we must avoid the production of free electrons in plasmas. At the same time, if we want to observe x-rays for the development of high-repetition-rate table-top soft x-ray lasers, we should strip all atoms in the plasmas to a necessary ionized stage by the optical-fieldionization in the field of a high-intensity laser pulse.

  15. Numerical modeling of thermal loading of diamond crystal in X-ray FEL oscillators

    Science.gov (United States)

    Song, Mei-Qi; Zhang, Qing-Min; Guo, Yu-Hang; Li, Kai; Deng, Hai-Xiao

    2016-04-01

    Due to high reflectivity and high resolution of X-ray pulses, diamond is one of the most popular Bragg crystals serving as the reflecting mirror and mono-chromator in the next generation of free electron lasers (FELs). The energy deposition of X-rays will result in thermal heating, and thus lattice expansion of the diamond crystal, which may degrade the performance of X-ray FELs. In this paper, the thermal loading effect of diamond crystal for X-ray FEL oscillators has been systematically studied by combined simulation with Geant4 and ANSYS, and its dependence on the environmental temperature, crystal size, X-ray pulse repetition rate and pulse energy are presented. Our results show that taking the thermal loading effects into account, X-ray FEL oscillators are still robust and promising with an optimized design. Supported by National Natural Science Foundation of China (11175240, 11205234, 11322550) and Program for Changjiang Scholars and Innovative Research Team in University (IRT1280)

  16. LUX — A Recirculating Linac-based Ultrafast X-ray Source

    Science.gov (United States)

    Corlett, J. N.; Barletta, W. A.; DeSantis, S.; Doolittle, L.; Fawley, W. M.; Green, M. A.; Heimann, P.; Leone, S. R.; Lidia, S.; Li, D.; Parmigiani, F.; Ratti, A.; Robinson, K.; Schoenlein, R.; Staples, J.; Wan, W.; Wells, R.; Wilcox, R.; Wolski, A.; Zholents, A.

    2004-05-01

    We describe the design of a proposed source of ultra-fast synchrotron radiation x-ray pulses based on a recirculating superconducting linac, with an integrated array of ultrafast laser systems. The source produces x-ray pulses with duration of 10-50 fs at a 10 kHz repetition rate, with tunability from EUV to hard x-ray regimes, and optimized for the study of ultra-fast dynamics. A high-brightness rf photocathode provides electron bunches. An injector linac accelerates the beam to the 100 MeV range, and is followed by four passes through a 700 MeV recirculating linac. Ultrafast hard x-ray pulses are obtained by a combination of electron bunch manipulation, transverse temporal correlation of the electrons, and x-ray pulse compression. EUV and soft x-ray pulses as short as 10 fs are generated in a harmonic-cascade free electron laser scheme. We describe the facility major systems and peformance.

  17. Development of a Sub-Picosecond Tunable X-Ray Source at the LLNL Electron Linac

    Energy Technology Data Exchange (ETDEWEB)

    Slaughter, D; Springer, P; Le Sage, G; Crane, J; Ditmire, T; Cowan, T; Anderson, S G; Rosenzweig, J B

    2001-08-31

    The use of ultrafast laser pulses to generate very high brightness, ultra short (fs to ps) pulses of x-rays is a topic of great interest to the x-ray user community. In principle, femtosecond-scale pump-probe experiments can be used to temporally resolve structural dynamics of materials on the time scale of atomic motion. The development of sub-ps x-ray pulses will make possible a wide range of materials and plasma physics studies with unprecedented time resolution. A current project at LLNL will provide such a novel x-ray source based on Thomson scattering of high power, short laser pulses with a high peak brightness, relativistic electron bunch. The system is based on a 5 mm-mrad normalized emittance photoinjector, a 100 MeV electron RF linac, and a 300 mJ, 35 fs solid-state laser system. The Thomson x-ray source produces ultra fast pulses with x-ray energies capable of probing into high-Z metals, and a high flux per pulse enabling single shot experiments. The system will also operate at a high repetition rate ({approx} 10 Hz).

  18. A recirculating linac based synchrotron light source for ultrafast x-ray science

    Energy Technology Data Exchange (ETDEWEB)

    Corlett, J.N.; Barry, W.; Byrd, J.M.; DeSantis, S.; Heimann, P.; Lidia, S.; Li, D.; Rimmer, R.; Robinson, K.; Schoenlein, R.; Tanabe, J.; Wang, S.; Wan, W.; Wells, R.; Zholents, A.; Placidi, M.; Pirkl, W.

    2002-05-30

    LBNL is pursuing a multi-divisional initiative that has this year further developed design studies and the scientific program for a facility dedicated to the production of x-ray pulses with ultra-short time duration. Our proposed x-ray facility [1] has the short x-ray pulse length ({approx};60 fs FWHM) necessary to study very fast dynamics, high flux (approximately 1011 photons/sec/0.1 percentBW) to study weakly scattering systems, and tuneability over 1-10 keV photon energy. The photon production section of the machine accomodates seven 2m long undulators and six 2T field dipole magnets. The x-ray pulse repetition rate of 10 kHz is matched to studies of dynamical processes (initiated by ultra-short laser pulses) that typicaly have a long recovery time or are not generally cyclic or reversible and need time to allow relaxation, replacement, or flow of the sample. The technique for producing ultra-short x-ray pulses uses relatively long electron bunches to minimise high-peak-current collective effects, and the ultimate x-ray duration is achieved by a combination of bunch manipulation and optical compression.

  19. Be/X-ray binaries

    CERN Document Server

    Reig, Pablo

    2011-01-01

    The purpose of this work is to review the observational properties of Be/X-ray binaries. The open questions in Be/X-ray binaries include those related to the Be star companion, that is, the so-called "Be phenomenon", such as, timescales associated to the formation and dissipation of the equatorial disc, mass-ejection mechanisms, V/R variability, and rotation rates; those related to the neutron star, such as, mass determination, accretion physics, and spin period evolution; but also, those that result from the interaction of the two constituents, such as, disc truncation and mass transfer. Until recently, it was thought that the Be stars' disc was not significantly affected by the neutron star. In this review, I present the observational evidence accumulated in recent years on the interaction between the circumstellar disc and the compact companion. The most obvious effect is the tidal truncation of the disc. As a result, the equatorial discs in Be/X-ray binaries are smaller and denser than those around isolat...

  20. Tunable Soft X-Ray Oscillators

    Energy Technology Data Exchange (ETDEWEB)

    Wurtele, Jonathan; Gandhi, Punut; Gu, X-W; Fawley, William M; Reinsch, Matthia; Penn, Gregory; Kim, K-J; Lindberg, Ryan; Zholents, Alexander

    2010-09-17

    A concept for a tunable soft x-ray free electron laser (FEL) photon source is presented and studied numerically. The concept is based on echo-enabled harmonic generation (EEHG), wherein two modulator-chicane sections impose high harmonic structure with much greater efficacy as compared to conventional high harmonic FELs that use only one modulator-chicane section. The idea proposed here is to replace the external laser power sources in the EEHG modulators with FEL oscillators, and to combine the bunching of the beam with the production of radiation. Tunability is accomplished by adjusting the magnetic chicanes while the two oscillators remain at a fixed frequency. This scheme eliminates the need to develop coherent sources with the requisite power, pulse length, and stability requirements by exploiting the MHz bunch repetition rates of FEL continuous wave (CW) sources driven by superconducting (SC) linacs. We present time-dependent GINGER simulation results for an EEHG scheme with an oscillator modulator at 43 nm employing 50percent reflective dielectric mirrors and a second modulator employing an external, 215-nm drive laser. Peak output of order 300 MW is obtained at 2.7 nm, corresponding to the 80th harmonic of 215 nm. An alternative single-cavity echo-oscillator scheme based on a 13.4 nm oscillator is investigated with time-independent simulations that a 180-MW peak power at final wavelength of 1.12 nm. Three alternate configurations that use separate bunches to produce the radiation for EEHG microbunching are also presented. Our results show that oscillator-based soft x-ray FELs driven by CWSC linacs are extremely attractive because of their potential to produce tunable radiation at high average power together with excellent longitudinal coherence and narrow spectral bandwidth.

  1. Femtosecond time-resolved X-ray absorption spectroscopy of liquid using a hard X-ray free electron laser in a dual-beam dispersive detection method.

    Science.gov (United States)

    Obara, Yuki; Katayama, Tetsuo; Ogi, Yoshihiro; Suzuki, Takayuki; Kurahashi, Naoya; Karashima, Shutaro; Chiba, Yuhei; Isokawa, Yusuke; Togashi, Tadashi; Inubushi, Yuichi; Yabashi, Makina; Suzuki, Toshinori; Misawa, Kazuhiko

    2014-01-13

    We present femtosecond time-resolved X-ray absorption spectroscopy of aqueous solution using a hard x-ray free electron laser (SACLA) and a synchronized Ti:sapphire laser. The instrumental response time is 200 fs, and the repetition rate of measurement is 10 Hz. A cylindrical liquid beam 100 μm in diameter of aqueous ammonium iron(III) oxalate solution is photoexcited at 400 nm, and the transient X-ray absorption spectra are measured in the K-edge region of iron, 7.10 - 7.26 keV, using a dual X-ray beam dispersive detection method. Each of the dual beams has the pulse energy of 1.4 μJ, and pump-induced absorbance change on the order of 10(-3) is successfully detected. The photoexcited iron complex exhibits a red shifted iron K-edge with the appearance time constant of 260 fs. The X-ray absorption difference spectra, with and without the pump pulses, are independent of time delay after 1.5 ps up to 100 ps, indicating that the photoexcited species is long-lived.

  2. X-Ray Astronomy

    Science.gov (United States)

    Wu, S. T.

    2000-01-01

    Dr. S. N. Zhang has lead a seven member group (Dr. Yuxin Feng, Mr. XuejunSun, Mr. Yongzhong Chen, Mr. Jun Lin, Mr. Yangsen Yao, and Ms. Xiaoling Zhang). This group has carried out the following activities: continued data analysis from space astrophysical missions CGRO, RXTE, ASCA and Chandra. Significant scientific results have been produced as results of their work. They discovered the three-layered accretion disk structure around black holes in X-ray binaries; their paper on this discovery is to appear in the prestigious Science magazine. They have also developed a new method for energy spectral analysis of black hole X-ray binaries; four papers on this topics were presented at the most recent Atlanta AAS meeting. They have also carried Monte-Carlo simulations of X-ray detectors, in support to the hardware development efforts at Marshall Space Flight Center (MSFC). These computation-intensive simulations have been carried out entirely on the computers at UAH. They have also carried out extensive simulations for astrophysical applications, taking advantage of the Monte-Carlo simulation codes developed previously at MSFC and further improved at UAH for detector simulations. One refereed paper and one contribution to conference proceedings have been resulted from this effort.

  3. X-ray lithography masking

    Science.gov (United States)

    Smith, Henry I. (Inventor); Lim, Michael (Inventor); Carter, James (Inventor); Schattenburg, Mark (Inventor)

    1998-01-01

    X-ray masking apparatus includes a frame having a supporting rim surrounding an x-ray transparent region, a thin membrane of hard inorganic x-ray transparent material attached at its periphery to the supporting rim covering the x-ray transparent region and a layer of x-ray opaque material on the thin membrane inside the x-ray transparent region arranged in a pattern to selectively transmit x-ray energy entering the x-ray transparent region through the membrane to a predetermined image plane separated from the layer by the thin membrane. A method of making the masking apparatus includes depositing back and front layers of hard inorganic x-ray transparent material on front and back surfaces of a substrate, depositing back and front layers of reinforcing material on the back and front layers, respectively, of the hard inorganic x-ray transparent material, removing the material including at least a portion of the substrate and the back layers of an inside region adjacent to the front layer of hard inorganic x-ray transparent material, removing a portion of the front layer of reinforcing material opposite the inside region to expose the surface of the front layer of hard inorganic x-ray transparent material separated from the inside region by the latter front layer, and depositing a layer of x-ray opaque material on the surface of the latter front layer adjacent to the inside region.

  4. Panoramic Dental X-Ray

    Science.gov (United States)

    ... Physician Resources Professions Site Index A-Z Panoramic Dental X-ray Panoramic dental x-ray uses a ... Your e-mail address: Personal message (optional): Bees: Wax: Notice: RadiologyInfo respects your privacy. Information entered here ...

  5. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... the body. X-rays are the oldest and most frequently used form of medical imaging. A bone ... bones. top of page How should I prepare? Most bone x-rays require no special preparation. You ...

  6. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... tissue shows up in shades of gray and air appears black. Until recently, x-ray images were ... position possible that still ensures x-ray image quality. top of page Who interprets the results and ...

  7. Soft X-ray Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Seely, John

    1999-05-20

    The contents of this report cover the following: (1) design of the soft x-ray telescope; (2) fabrication and characterization of the soft x-ray telescope; and (3) experimental implementation at the OMEGA laser facility.

  8. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... of page What are some common uses of the procedure? A bone x-ray is used to: ... and x-rays. top of page What does the equipment look like? The equipment typically used for ...

  9. Bone X-Ray (Radiography)

    Science.gov (United States)

    ... clothing that might interfere with the x-ray images. Women should always inform their physician and x-ray ... small burst of radiation that passes through the body, recording an image on photographic film or a special detector. Different ...

  10. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... standards used by radiology professionals. Modern x-ray systems have very controlled x-ray beams and dose control methods to minimize stray (scatter) radiation. This ensures ...

  11. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... current x-ray images for diagnosis and disease management. top of page How is the procedure performed? ... position possible that still ensures x-ray image quality. top of page Who interprets the results and ...

  12. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... Us News Physician Resources Professions Site Index A-Z X-ray (Radiography) - Bone Bone x-ray uses ... assess trauma patients in emergency departments. A CT scan can image complicated fractures, subtle fractures or dislocations. ...

  13. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... patient. top of page How does the procedure work? X-rays are a form of radiation like ... very controlled x-ray beams and dose control methods to minimize stray (scatter) radiation. This ensures that ...

  14. Abdomen X-Ray (Radiography)

    Science.gov (United States)

    ... Professions Site Index A-Z X-ray (Radiography) - Abdomen Abdominal x-ray uses a very small dose ... to produce pictures of the inside of the abdominal cavity. It is used to evaluate the stomach, liver, ...

  15. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... radiation like light or radio waves. X-rays pass through most objects, including the body. Once it ... organs, allow more of the x-rays to pass through them. As a result, bones appear white ...

  16. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... current x-ray images for diagnosis and disease management. top of page How is the procedure performed? ... position possible that still ensures x-ray image quality. top of page Who interprets the results and ...

  17. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... and x-rays. A Word About Minimizing Radiation Exposure Special care is taken during x-ray examinations ... patient's body not being imaged receive minimal radiation exposure. top of page What are the limitations of ...

  18. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... fracture. guide orthopedic surgery, such as spine repair/fusion, joint replacement and fracture reductions. look for injury, ... and Media Arthritis X-ray, Interventional Radiology and Nuclear Medicine Radiation Safety Images related to X-ray ( ...

  19. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... of page What are some common uses of the procedure? A bone x-ray is used to: ... and x-rays. top of page What does the equipment look like? The equipment typically used for ...

  20. Characterization of an ultrafast Bragg-Switch for shortening hard x-ray pulses

    Science.gov (United States)

    Sander, M.; Koc, A.; Kwamen, C. T.; Michaels, H.; Reppert, A. v.; Pudell, J.; Zamponi, F.; Bargheer, M.; Sellmann, J.; Schwarzkopf, J.; Gaal, P.

    2016-11-01

    We present a nanostructured device that functions as photoacoustic hard x-ray switch. The device is triggered by femtosecond laser pulses and allows for temporal gating of hard x-rays on picosecond (ps) timescales. It may be used for pulse picking or even pulse shortening in 3rd generation synchrotron sources. Previous approaches mainly suffered from insufficient switching contrasts due to excitation-induced thermal distortions. We present a new approach where thermal distortions are spatially separated from the functional switching layers in the structure. Our measurements yield a switching contrast of 14, which is sufficient for efficient hard x-ray pulse shortening. The optimized structure also allows for utilizing the switch at high repetition rates of up to 208 kHz.

  1. The X-ray Correlation Spectroscopy instrument at the Linac Coherent Light Source

    Energy Technology Data Exchange (ETDEWEB)

    Alonso-Mori, Roberto; Caronna, Chiara; Chollet, Matthieu; Curtis, Robin; Damiani, Daniel S.; Defever, Jim; Feng, Yiping; Flath, Daniel L.; Glownia, James M. [Linac Coherent Light Source, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025 (United States); Lee, Sooheyong [Linac Coherent Light Source, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025 (United States); Hasylab at DESY, Notkestrasse 85, D-22607 Hamburg (Germany); Lemke, Henrik T.; Nelson, Silke; Bong, Eric; Sikorski, Marcin; Song, Sanghoon; Srinivasan, Venkat; Stefanescu, Daniel; Zhu, Diling; Robert, Aymeric, E-mail: aymeric@slac.stanford.edu [Linac Coherent Light Source, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025 (United States)

    2015-04-14

    A description of the X-ray Correlation Spectroscopy instrument at the Linac Coherent Light Source is presented. Recent highlights illustrate the coherence properties of the source as well as some recent dynamics measurements and future directions. The X-ray Correlation Spectroscopy instrument is dedicated to the study of dynamics in condensed matter systems using the unique coherence properties of free-electron lasers. It covers a photon energy range of 4–25 keV. The intrinsic temporal characteristics of the Linac Coherent Light Source, in particular the 120 Hz repetition rate, allow for the investigation of slow dynamics (milliseconds) by means of X-ray photon correlation spectroscopy. Double-pulse schemes could probe dynamics on the picosecond timescale. A description of the instrument capabilities and recent achievements is presented.

  2. Theory of recombination x-ray lasers based on optical-field ionization

    Energy Technology Data Exchange (ETDEWEB)

    Eder, D.C.; Amendt, P.; DaSilva, L.B.; London, R.A.; Rosen, M.D.; Wilks, S.C. [Lawrence Livermore National Lab., CA (United States); Donnelly, T.D.; Falcone, R.W. [Univ. of California at Berkeley, Berkeley, CA (United States)

    1994-12-01

    Ultrashort-pulse, high-intensity laser drivers have the potential for creating tabletop-size x-ray lasers by ionizing the target gas via the electric field of the laser pulse. For appropriate plasma conditions following ionization, lasing can occur during the subsequent rapid recombination. A review of the theory and modeling for these optical-field-ionized x-ray lasers is presented. Particular attention is given to the issues of electron beating and ionization-induced refraction. We summarize modeling in support of experiments where evidence of lasing in H-like Li at 135 {Angstrom} was obtained. In addition, we present modeling results for lasing in Li-like N at 247 {Angstrom}. We briefly discuss new applications appropriate for tabletop-size high-repetition-rate x-ray lasers.

  3. An injector for the proposed Berkeley Ultrafast X-Ray Light Source

    Energy Technology Data Exchange (ETDEWEB)

    Lidia, Steven; Corlett, John; Pusina, Jan; Staples, John; Zholents, Alexander

    2003-05-19

    Berkeley Lab has proposed to build a recirculating linac based X-ray source for ultra-fast dynamic studies [1]. This machine requires a flat electron beam with a small vertical emittance and large x/y emittance ratio to allow for compression of spontaneous undulator emission of soft and hard x-ray pulses, and a low-emittance, round electron beam for coherent emission of soft x-rays via the FEL process based on cascaded harmonic generation [2]. We propose an injector system consisting of two high gradient high repetition rate photo cathode guns [3] (one for each application), an {approx}120 MeV super conducting linear accelerator, a 3rd harmonic cavity for linearization of the longitudinal phase space, and a bunch compressor. We present details of the design and the results of particle tracking studies using several computer codes.

  4. Wakefield-acceleration of relativistic electrons with few-cycle laser pulses at kHz-repetition-rate

    Science.gov (United States)

    Guenot, Diego; Gustas, Dominykas; Vernier, Aline; Boehle, Frederik; Beaurepaire, Benoit; Lopez-Martens, Rodrigo; Faure, Jerome; Appli Team

    2016-10-01

    The generation of relativistic electron beams using laser wakefield acceleration has become a standard technique, providing low emittance electron bunches with femtosecond durations. However, this technique usually requires multi-ten-terawatt lasers and is thus limited to low repetition-rate (typically 10 Hz or less). We have recently demonstrated the generation of few MeV electrons using 2.5-mJ, 4-fs, 1-kHz repetition-rate laser pulses, focused to relativistic intensity onto a gas jet with electron density 1020 cm-3. We have investigated the influence of the pulse duration, the gas density. We demonstrated that an electron beam with a charge in the range of 10-fC/shot, with a divergence of 20-mrad and a peaked spectrum with energies between 2 and 4 MeV can be generated at kHz repetition-rate. These results confirm the possibility of using few-cycle laser pulses with very low energy for exciting wakefields in the bubble regime and for trapping electrons, as predicted by PIC simulations. This kHz electron source is ideally suited for performing electron diffraction experiments with very high temporal resolution. Our results also open the way to other applications, such as the generation of a kHz ultrafast X-ray source. ERC femtoelec.

  5. Effects of high-repetition-rate femtosecond laser micromachining on the physical and chemical properties of polylactide (PLA).

    Science.gov (United States)

    Jia, Wei; Luo, Yiming; Yu, Jian; Liu, Bowen; Hu, Minglie; Chai, Lu; Wang, Chingyue

    2015-10-19

    The effects of femtosecond laser ablation, with 115 fs pulses at 1040 nm wavelength and 57 MHz repetition-rate, on the physical and chemical properties of polylactide (PLA) were studied in air and in water. The surface of the PLA sample ablated by high-repetition-rate femtosecond laser was analysed using field emission scanning electron microscopy, infrared spectroscopy, raman spectroscopy, as well as X-ray photoelectron spectroscopy. Compared with the experiments in the air at ambient temperature, melting resolidification was negligible for the experiments conducted under water. Neither in air nor under water did oxidation and crystallization process take place in the laser ablated surface. In addition, the intensity of some oxygen related peaks increased for water experiments, probably due to the hydrolysis. Meantime, the chemical shift to higher energies appeared in C1s XPS spectrum of laser processing in water. Interestingly, a large amount of defects were observed after laser processing in air, while no significant change was shown under water experiments. This indicates that thermal and mechanical effects by high-repetition-rate femtosecond laser ablation in water are quite limited, which could be even ignored.

  6. X-Ray Exam: Hip

    Science.gov (United States)

    ... Old Feeding Your 1- to 2-Year-Old X-Ray Exam: Hip KidsHealth > For Parents > X-Ray Exam: Hip A A A What's in ... español Radiografía: cadera What It Is A hip X-ray is a safe and painless test that ...

  7. X-Ray Exam: Finger

    Science.gov (United States)

    ... Old Feeding Your 1- to 2-Year-Old X-Ray Exam: Finger KidsHealth > For Parents > X-Ray Exam: Finger A A A What's in ... español Radiografía: dedo What It Is A finger X-ray is a safe and painless test that ...

  8. X-Ray Exam: Foot

    Science.gov (United States)

    ... Old Feeding Your 1- to 2-Year-Old X-Ray Exam: Foot KidsHealth > For Parents > X-Ray Exam: Foot A A A What's in ... español Radiografía: pie What It Is A foot X-ray is a safe and painless test that ...

  9. X-Ray Exam: Wrist

    Science.gov (United States)

    ... Old Feeding Your 1- to 2-Year-Old X-Ray Exam: Wrist KidsHealth > For Parents > X-Ray Exam: Wrist A A A What's in ... español Radiografía: muñeca What It Is A wrist X-ray is a safe and painless test that ...

  10. X-Ray Exam: Ankle

    Science.gov (United States)

    ... Old Feeding Your 1- to 2-Year-Old X-Ray Exam: Ankle KidsHealth > For Parents > X-Ray Exam: Ankle A A A What's in ... español Radiografía: tobillo What It Is An ankle X-ray is a safe and painless test that ...

  11. X-Ray Exam: Pelvis

    Science.gov (United States)

    ... Old Feeding Your 1- to 2-Year-Old X-Ray Exam: Pelvis KidsHealth > For Parents > X-Ray Exam: Pelvis A A A What's in ... español Radiografía: pelvis What It Is A pelvis X-ray is a safe and painless test that ...

  12. X-Ray Exam: Forearm

    Science.gov (United States)

    ... Old Feeding Your 1- to 2-Year-Old X-Ray Exam: Forearm KidsHealth > For Parents > X-Ray Exam: Forearm A A A What's in ... español Radiografía: brazo What It Is A forearm X-ray is a safe and painless test that ...

  13. X-ray selected BALQSOs

    CERN Document Server

    Page, M J; Ceballos, M; Corral, A; Ebrero, J; Esquej, P; Krumpe, M; Mateos, S; Rosen, S; Schwope, A; Streblyanska, A; Symeonidis, M; Tedds, J A; Watson, M G

    2016-01-01

    We study a sample of six X-ray selected broad absorption line (BAL) quasi-stellar objects (QSOs) from the XMM-Newton Wide Angle Survey. All six objects are classified as BALQSOs using the classic balnicity index, and together they form the largest sample of X-ray selected BALQSOs. We find evidence for absorption in the X-ray spectra of all six objects. An ionized absorption model applied to an X-ray spectral shape that would be typical for non-BAL QSOs (a power law with energy index alpha=0.98) provides acceptable fits to the X-ray spectra of all six objects. The optical to X-ray spectral indices, alpha_OX, of the X-ray selected BALQSOs, have a mean value of 1.69 +- 0.05, which is similar to that found for X-ray selected and optically selected non-BAL QSOs of similar ultraviolet luminosity. In contrast, optically-selected BALQSOs typically have much larger alpha_OX and so are characterised as being X-ray weak. The results imply that X-ray selection yields intrinsically X-ray bright BALQSOs, but their X-ray sp...

  14. X-ray Crystallography Facility

    Science.gov (United States)

    2000-01-01

    Edward Snell, a National Research Council research fellow at NASA's Marshall Space Flight Center (MSFC), prepares a protein crystal for analysis by x-ray crystallography as part of NASA's structural biology program. The small, individual crystals are bombarded with x-rays to produce diffraction patterns, a map of the intensity of the x-rays as they reflect through the crystal.

  15. Efficient Pumping Schemes for High Average Brightness Collisional X-ray Lasers

    Energy Technology Data Exchange (ETDEWEB)

    Keenan, R; Dunn, J; Shlyaptsev, V N; Smith, R F; Patel, P K; Price, D F

    2003-10-07

    Advances in transient collisional x-ray lasers have been demonstrated over the last 5 years as a technique for achieving tabletop soft x-ray lasers using 2-10 J of laser pump energy. The high peak brightness of these sources operating in the high output saturation regime, in the range of 10{sup 24}-10{sup 25} ph. mm{sup -2} mrad{sup -2} s-1 (0.1% BW){sup -1}, is ideal for many applications requiring high photon fluence in a single short burst. However, the pump energy required for these x-ray lasers is still relatively high and limits the x-ray laser repetition rate to 1 shot every few minutes. Higher repetition rate collisional schemes have been reported and show some promise for high output in the future. We report a novel technique for enhancing the coupling efficiency of the laser pump into the gain medium that could lead to enhanced x-ray inversion with a factor of ten reduction in the drive energy. This has been applied to the collisional excitation scheme for Ni-like Mo at 18.9 nm and x-ray laser output has been demonstrated. Preliminary results show lasing on a single shot of the optical laser operating at 10 Hz and with 70 mJ in the short pulse. Such a proposed source would have higher average brightness, {approx}10{sup 14} ph. mm{sup -2} mrad{sup -2} s{sup -1} (0.1% BW){sup -1}, than present bending magnet 3rd generation synchrotron sources operating at the same spectral range.

  16. Modeling and characterization of X-ray yield in a polychromatic, lab-scale, X-ray computed tomography system

    Energy Technology Data Exchange (ETDEWEB)

    Mertens, J.C.E.; Chawla, Nikhilesh, E-mail: nchawla@asu.edu

    2015-05-21

    A modular X-ray computed micro-tomography (µXCT) system is characterized in terms of X-ray yield resulting both from the generated X-ray spectrum and from X-ray detection with an energy-sensitive detector. The X-ray computed tomography system is composed of a commercially available cone-beam microfocus X-ray source and a modular optically-coupled-CCD-scintillator X-ray detector. The X-ray yield is measured and reported in units independent from exposure time, X-ray tube beam target current, and cone-beam-to-detector geometry. The polychromatic X-ray source is modeled as a broad Bremsstrahlung X-ray spectrum in order to understand the effect of the controllable parameters, that is, X-ray tube accelerating voltage and X-ray beam filtering. An approach is adopted which expresses the absolute number of emitted X-rays. The response of the energy-sensitive detector to the modeled spectrum is modeled as a function of scintillator composition and thickness. The detection efficiency model for the polychromatic X-ray detector considers the response of the light collection system and the electronic imaging array in order to predict absolute count yield under the studied conditions. The modeling approach is applied to the specific hardware implemented in the current µXCT system. The model's predictions for absolute detection rate are in reasonable agreement with measured values under a range of conditions applied to the system for X-ray microtomography imaging, particularly for the LuAG:Ce scintillator material.

  17. Use of a minimum rate of change formalism to quantify variability of extragalactic X-ray sources

    Science.gov (United States)

    Schwartz, Daniel A.

    1987-01-01

    A method to obtain rigorous, quantitative constraints on the rate of variability is suggested. The method is motivated by the case when the existence of time variability is unequivocal, but the statistical uncertainties are too large to apply more direct methods such as power spectrum analysis. Conceptually the data are fitted to a function of time and a set of free parameters. The method of Lagrange multipliers is used to solve for that parameter set which minimizes the value of the derivative at time t(m). The result can be related physically to the minimum efficiency with which rest mass must be converted to radiation energy. Slightly different formulations of the general principal are used to estimate maximum source size scales associated with the variability.

  18. SMM x ray polychromator

    Science.gov (United States)

    Saba, J. L. R.

    1993-01-01

    The objective of the X-ray Polychromator (XRP) experiment was to study the physical properties of solar flare plasma and its relation to the parent active region to understand better the flare mechanism and related solar activity. Observations were made to determine the temperature, density, and dynamic structure of the pre-flare and flare plasma as a function of wavelength, space and time, the extent to which the flare plasma departs from thermal equilibrium, and the variation of this departure with time. The experiment also determines the temperature and density structure of active regions and flare-induced changes in the regions.

  19. X-ray today

    Energy Technology Data Exchange (ETDEWEB)

    Neitzel, U. [Philips Medical Systems, Hamburg (Germany)

    2001-09-01

    The interest attracted by the new imaging modalities tends to overshadow the continuing importance of projection radiography and fluoroscopy. Nevertheless, projection techniques still represent by far the greatest proportion of diagnostic imaging examinations, and play an essential role in the growing number of advanced interventional procedures. This article describes some of the latest developments in X-ray imaging technology, using two products from the Philips range as examples: the Integris Allura cardiovascular system with 3D image reconstruction, and the BV Pulsera: a high-end, multi-functional mobile C-arm system with cardiac capabilities. (orig.)

  20. The Very Local Universe in X-Rays

    Science.gov (United States)

    Ptak, A.

    2011-01-01

    There are many open questions in X-ray observations of the Galactic neighborhood and nearby galaxies, such as the properties of the hot ISM and accreting sources, the X-ray/star-formation rate correlation and how the X-ray luminosity function of starburst galaxies. We discuss how these would be addressed by very wide-area (> 100 sq. deg.) X-ray surveys and upcoming X-ray missions. In particular planned NuStar observations of the Galaxy and nearby galaxies will be highlighted.

  1. Binary Black Hole Merger Rates Inferred from Luminosity Function of Ultra-Luminous X-ray Sources: Implications to the Origin of GW150914

    CERN Document Server

    Inoue, Yoshiyuki; Isobe, Naoki

    2016-01-01

    The Advanced Laser Interferometer Gravitational-Wave Observatory (aLIGO) has detected direct signals of gravitational waves (GWs) from GW150914. The event was a merger of a binary black holes whose masses are $36^{+5}_{-4}M_{\\odot}$ and $29^{+4}_{-4}M_{\\odot}$. Such binary systems are expected to be formed in either isolated binary systems or dense stellar environments. Here we derived the binary black hole merger rate for isolated binary systems based on the nearby ultra-luminous X-ray source (ULX) luminosity function (LF). We obtained the binary black hole merger rate as $1.9 ({t}_{\\rm ULX}/{1 \\ \\rm Myr})^{-1} \\lambda^{-0.6} \\exp{(-0.30\\lambda)} \\ {\\rm Gpc^{-3}\\ yr^{-1}}$, where $t_{\\rm ULX}$ is the typical duration of the ULX phase and $\\lambda$ is the Eddington ratio. This is comparable to the event rate inferred from the detection of GW150914 as well as the predictions based on binary population synthesis models. Although we are currently unable to constrain $\\lambda$ due to the uncertainties of our mode...

  2. Design of a high repetition rate S-band photocathode gun

    Science.gov (United States)

    Han, Jang-Hui; Cox, Matthew; Huang, Houcheng; Pande, Shivaji

    2011-08-01

    Photocathode RF guns have been developed in many laboratories for generating high quality electron beams for free-electron lasers based on linear accelerators. Such guns can generate electron beams with an exceptionally high peak current as well as a small transverse emittance. Their applications have been recently expanded for ultrafast electron diffraction, coherent terahertz radiation, and X-ray or γ-ray radiation by Compton scattering. In this paper, we design an S-band normal-conducting gun with capabilities of high quality beam generation and high repetition rate operation. The RF design and thermal analysis of the gun cavity and coupler are introduced. Optimal position of the gun focusing solenoid for low emittance beam generation is found by performing particle tracking simulations. Then, the gun system is designed to be able to afford the optimal solenoid position. The cooling-water channel surrounding the gun cavity and coupler is designed and analyzed numerically. The pressure in the gun is simulated with a vacuum model containing the detailed inner structure of the gun. An injector for a free-electron laser application is designed by using this gun and the beam dynamics simulation is shown. A cold test with a prototype gun for confirmation of the RF design is reported.

  3. Design of a VHF-band RF Photoinjector with Megahertz BeamRepetition Rate

    Energy Technology Data Exchange (ETDEWEB)

    Staples, J.W.; Baptiste, K.M.; Corlett, J.N.; Kwiatkowski, S.; Lidia, S.M.; Qiang, J.; Sannibale, F.; Sonnad, K.G.; Virostek, S.P.; Wells, R.P.

    2007-06-01

    New generation accelerator-based X-ray light sources require high quality beams with high average brightness. Normal conducting L- and S-band photoinjectors are limited in repetition rate and D-C (photo)injectors are limited in field strength at the cathode. We propose a low frequency normal-conducting cavity, operating at 50 to 100MHz CW, to provide beam bunches of up to the cavity frequency. The photoinjector uses a re-entrant cavity structure, requiring less than 100 kW CW, with a peak wall power density less than 10 W/cm{sup 2}. The cavity will support a vacuum down to 10 picoTorr, with a load-lock mechanism for easy replacement of photocathodes. The photocathode can be embedded in a magnetic field to provide correlations useful for emittance exchange. Beam dynamics simulations indicate that normalized emittances smaller than 1 mm-mrad are possible with gap voltage of 750 kV, with fields up to 20 MV/m at the photocathode, for 1 nanocoulomb charge per bunch after acceleration and emittance compensation. Long-bunch operation (10's of picosecond) is made possible by the low cavity frequency, permitting low bunch current at the 750 kV gap voltage.

  4. Comparative analysis of dose rates in bricks determined by neutron activation analysis, alpha counting and X-ray fluorescence analysis for the thermoluminescence fine grain dating method

    Science.gov (United States)

    Bártová, H.; Kučera, J.; Musílek, L.; Trojek, T.

    2014-11-01

    In order to evaluate the age from the equivalent dose and to obtain an optimized and efficient procedure for thermoluminescence (TL) dating, it is necessary to obtain the values of both the internal and the external dose rates from dated samples and from their environment. The measurements described and compared in this paper refer to bricks from historic buildings and a fine-grain dating method. The external doses are therefore negligible, if the samples are taken from a sufficient depth in the wall. However, both the alpha dose rate and the beta and gamma dose rates must be taken into account in the internal dose. The internal dose rate to fine-grain samples is caused by the concentrations of natural radionuclides 238U, 235U, 232Th and members of their decay chains, and by 40K concentrations. Various methods can be used for determining trace concentrations of these natural radionuclides and their contributions to the dose rate. The dose rate fraction from 238U and 232Th can be calculated, e.g., from the alpha count rate, or from the concentrations of 238U and 232Th, measured by neutron activation analysis (NAA). The dose rate fraction from 40K can be calculated from the concentration of potassium measured, e.g., by X-ray fluorescence analysis (XRF) or by NAA. Alpha counting and XRF are relatively simple and are accessible for an ordinary laboratory. NAA can be considered as a more accurate method, but it is more demanding regarding time and costs, since it needs a nuclear reactor as a neutron source. A comparison of these methods allows us to decide whether the time- and cost-saving simpler techniques introduce uncertainty that is still acceptable.

  5. X-ray lithography source

    Science.gov (United States)

    Piestrup, Melvin A.; Boyers, David G.; Pincus, Cary

    1991-01-01

    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.

  6. High voltage high repetition rate pulse using Marx topology

    Science.gov (United States)

    Hakki, A.; Kashapov, N.

    2015-06-01

    The paper describes Marx topology using MOSFET transistors. Marx circuit with 10 stages has been done, to obtain pulses about 5.5KV amplitude, and the width of the pulses was about 30μsec with a high repetition rate (PPS > 100), Vdc = 535VDC is the input voltage for supplying the Marx circuit. Two Ferrite ring core transformers were used to control the MOSFET transistors of the Marx circuit (the first transformer to control the charging MOSFET transistors, the second transformer to control the discharging MOSFET transistors).

  7. A Recirculating Linac-Based Facility for Ultrafast X-Ray Science

    Energy Technology Data Exchange (ETDEWEB)

    J. N. Corlett; W. A. Barletta; S. DeSantis; L. Doolittle; W. M. Fawley; M.A. Green; P. Heimann; S. Leone; S. Lidia; D. Li; A. Ratti; K. Robinson; R. Schoenlein; J. Staples; W. Wan; R. Wells; A.Wolski; A. Zholents; F. Parmigiani; M. Placidi; W. Pirkl; R. A. Rimmer; S. Wang

    2003-05-01

    We present an updated design for a proposed source of ultra-fast synchrotron radiation pulses based on a recirculating superconducting linac [1,2], 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 f our passes through a 600-720 MeV recirculating linac. We outline the major technical components of the proposed facility.

  8. A recirculating linac-based facility for ultrafast X-ray science

    Energy Technology Data Exchange (ETDEWEB)

    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.

    2003-05-06

    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.

  9. Examination of the role of the $^{14}$O($\\alpha$,$p$)$^{17}$F reaction rate in type I x-ray bursts

    CERN Document Server

    Hu, J; Parikh, A; Xu, S W; Yamaguchi, H; Kahl, D; Ma, P; Su, J; Wang, H W; Nakao, T; Wakabayashi, Y; Teranishi, T; Hahn, K I; Moon, J Y; Jung, H S; Hashimoto, T; Chen, A A; Irvine, D; Lee, C S; Kubono, S

    2014-01-01

    The $^{14}$O($\\alpha$,$p$)$^{17}$F reaction is one of the key reactions involved in the breakout from the hot-CNO cycle to the rp-process in type I x-ray bursts (XRBs). The resonant properties in the compound nucleus $^{18}$Ne have been investigated through resonant elastic scattering of $^{17}$F+$p$. The radioactive $^{17}$F beam was separated by the CNS Radioactive Ion Beam separator (CRIB) and bombarded a thick H$_2$ gas target at 3.6 MeV/nucleon. The recoiling light particles were measured by three ${\\Delta}$E-E silicon telescopes at laboratory angles of $\\theta$$_{lab}$$\\approx$3$^\\circ$, 10$^\\circ$ and 18$^\\circ$, respectively. Five resonances at $E_{x}$=6.15, 6.28, 6.35, 6.85, and 7.05 MeV were observed in the excitation functions, and their spin-parities have been determined based on an $R$-matrix analysis. In particular, $J^{\\pi}$=1$^-$ was firmly assigned to the 6.15-MeV state which dominates the thermonuclear $^{14}$O($\\alpha$,$p$)$^{17}$F rate below 2 GK. As well, a possible new excited state in $...

  10. Bottle microresonator broadband and low repetition rate frequency comb generator

    CERN Document Server

    Dvoyrin, V

    2016-01-01

    We propose a new type of broadband and low repetition rate frequency comb generator which has the shape of an elongated and nanoscale-shallow optical bottle microresonator created at the surface of an optical fiber. The free spectral range (FSR) of the broadband azimuthal eigenfrequency series of this resonator is the exact multiple of the FSR of the dense and narrowband axial series. The effective radius variation of the microresonator is close to a parabola with a nanoscale height which is greater or equal to lambda/2pi*n0 (here lambda is the characteristic radiation wavelength and n0 is the refractive index of the microresonator material). Overall, the microresonator possesses a broadband, small FSR, and accurately equidistant spectrum convenient for the generation of a broadband and low repetition rate optical frequency comb. It is shown that this comb can be generated by pumping with a cw laser, which radiation frequency matches a single axial eigenfrequency of the microresonator, or, alternatively, by p...

  11. Final Report, Photocathodes for High Repetition Rate Light Sources

    Energy Technology Data Exchange (ETDEWEB)

    Ben-Zvi, Ilan [Stony Brook University

    2014-04-20

    This proposal brought together teams at Brookhaven National Laboratory (BNL), Lawrence Berkeley National Laboratory (LBNL) and Stony Brook University (SBU) to study photocathodes for high repetition rate light sources such as Free Electron Lasers (FEL) and Energy Recovery Linacs (ERL). The work done under this grant comprises a comprehensive program on critical aspects of the production of the electron beams needed for future user facilities. Our program pioneered in situ and in operando diagnostics for alkali antimonide growth. The focus is on development of photocathodes for high repetition rate Free Electron Lasers (FELs) and Energy Recovery Linacs (ERLs), including testing SRF photoguns, both normal-conducting and superconducting. Teams from BNL, LBNL and Stony Brook University (SBU) led this research, and coordinated their work over a range of topics. The work leveraged a robust infrastructure of existing facilities and the support was used for carrying out the research at these facilities. The program concentrated in three areas: a) Physics and chemistry of alkali-antimonide cathodes b) Development and testing of a diamond amplifier for photocathodes c) Tests of both cathodes in superconducting RF photoguns and copper RF photoguns

  12. Accurate prediction of X-ray pulse properties from a free-electron laser using machine learning

    Science.gov (United States)

    Sanchez-Gonzalez, A.; Micaelli, P.; Olivier, C.; Barillot, T. R.; Ilchen, M.; Lutman, A. A.; Marinelli, A.; Maxwell, T.; Achner, A.; Agåker, M.; Berrah, N.; Bostedt, C.; Bozek, J. D.; Buck, J.; Bucksbaum, P. H.; Montero, S. Carron; Cooper, B.; Cryan, J. P.; Dong, M.; Feifel, R.; Frasinski, L. J.; Fukuzawa, H.; Galler, A.; Hartmann, G.; Hartmann, N.; Helml, W.; Johnson, A. S.; Knie, A.; Lindahl, A. O.; Liu, J.; Motomura, K.; Mucke, M.; O'Grady, C.; Rubensson, J.-E.; Simpson, E. R.; Squibb, R. J.; Såthe, C.; Ueda, K.; Vacher, M.; Walke, D. J.; Zhaunerchyk, V.; Coffee, R. N.; Marangos, J. P.

    2017-06-01

    Free-electron lasers providing ultra-short high-brightness pulses of X-ray radiation have great potential for a wide impact on science, and are a critical element for unravelling the structural dynamics of matter. To fully harness this potential, we must accurately know the X-ray properties: intensity, spectrum and temporal profile. Owing to the inherent fluctuations in free-electron lasers, this mandates a full characterization of the properties for each and every pulse. While diagnostics of these properties exist, they are often invasive and many cannot operate at a high-repetition rate. Here, we present a technique for circumventing this limitation. Employing a machine learning strategy, we can accurately predict X-ray properties for every shot using only parameters that are easily recorded at high-repetition rate, by training a model on a small set of fully diagnosed pulses. This opens the door to fully realizing the promise of next-generation high-repetition rate X-ray lasers.

  13. Topological X-Rays Revisited

    Science.gov (United States)

    Lynch, Mark

    2012-01-01

    We continue our study of topological X-rays begun in Lynch ["Topological X-rays and MRI's," iJMEST 33(3) (2002), pp. 389-392]. We modify our definition of a topological magnetic resonance imaging and give an affirmative answer to the question posed there: Can we identify a closed set in a box by defining X-rays to probe the interior and without…

  14. X-ray instrumentation for SR beamlines

    CERN Document Server

    Kovalchuk, M V; Zheludeva, S I; Aleshko-Ozhevsky, O P; Arutynyan, E H; Kheiker, D M; Kreines, A Y; Lider, V V; Pashaev, E M; Shilina, N Y; Shishkov, V A

    2000-01-01

    The main possibilities and parameters of experimental X-ray stations are presented: 'Protein crystallography', 'X-ray structure analysis', 'High-precision X-ray optics', 'X-ray crystallography and material science', 'X-ray topography', 'Photoelectron X-ray standing wave' that are being installed at Kurchatov SR source by A.V. Shubnikov Institute of Crystallography.

  15. X-ray Fluorescence Sectioning

    CERN Document Server

    Cong, Wenxiang

    2012-01-01

    In this paper, we propose an x-ray fluorescence imaging system for elemental analysis. The key idea is what we call "x-ray fluorescence sectioning". Specifically, a slit collimator in front of an x-ray tube is used to shape x-rays into a fan-beam to illuminate a planar section of an object. Then, relevant elements such as gold nanoparticles on the fan-beam plane are excited to generate x-ray fluorescence signals. One or more 2D spectral detectors are placed to face the fan-beam plane and directly measure x-ray fluorescence data. Detector elements are so collimated that each element only sees a unique area element on the fan-beam plane and records the x-ray fluorescence signal accordingly. The measured 2D x-ray fluorescence data can be refined in reference to the attenuation characteristics of the object and the divergence of the beam for accurate elemental mapping. This x-ray fluorescence sectioning system promises fast fluorescence tomographic imaging without a complex inverse procedure. The design can be ad...

  16. Soft X-ray optics

    CERN Document Server

    Spiller, Eberhard A

    1993-01-01

    This text describes optics mainly in the 10 to 500 angstrom wavelength region. These wavelengths are 50 to 100 times shorter than those for visible light and 50 to 100 times longer than the wavelengths of medical x rays or x-ray diffraction from natural crystals. There have been substantial advances during the last 20 years, which one can see as an extension of optical technology to shorter wavelengths or as an extension of x-ray diffraction to longer wavelengths. Artificial diffracting structures like zone plates and multilayer mirrors are replacing the natural crystals of x-ray diffraction.

  17. X-ray Absorption Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Yano, Junko; Yachandra, Vittal K.

    2009-07-09

    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.

  18. Kilohertz sources of hard x rays and fast ions with femtosecond laser plasmas

    Science.gov (United States)

    Thoss, A.; Richardson, M.; Korn, G.; Faubel, M.; Stiel, H.; Vogt, U.; Elsaesser, T.

    2003-01-01

    We demonstrate a new, stable, kilohertz femtosecond laser plasma source of hard-x-ray continuum and Kα emission that uses a microscopic liquid jet target that is continuous and debris free. Plasmas produced by ultrashort (50-fs) intense laser pulses from a fine (10-30-μm diameter) liquid Ga jet emit bright 9.3- and 10.3-keV Kα and Kβ lines superimposed on a multikilovolt bremmstrahlung continuum. Kilohertz femtosecond x-ray sources will find many applications in time-resolved x-ray diffraction and microscopy studies. As high-intensity lasers become more compact and operate at increasingly high repetition-rates, they require a target configuration that is both repeatable from shot to shot and debris free. Our target provides a pristine, unperturbed filament surface at rates >100 kHz. A number of liquid metal targets are considered. We show the hard-x-ray spectrum described above. The source was generated by a 50-fs-duration, 1-kHz, 2-W, high-intensity Ti:sapphire laser. Using the same technology, we also generate forward-going sub-mega-electron-volt (sub-MeV) protons from a 10-μm liquid water target at 1-kHz repetition rates. Kilohertz sources of high-energy ions will find many applications in time-resolved particle interaction studies and will lead to efficient generation of short-lived isotopes for use in nuclear medicine and other applications. The protons were detected with CR-39 track detectors in both the forward and the backward directions up to energies of ~500 keV. As the intensity of compact high-repetition-rate lasers sources increases, we can expect improvements in the energy, conversion efficiency, and directionality to occur. The effect of these developments is discussed. As compact, high-repetition-rate femtosecond laser technology reaches focused intensities of ~1019 W/cm2, many new applications of high-repetition-rate hard-x-ray and MeV ion sources will become practical.

  19. Observation of Laser Induced Magnetization Dynamics in Co/Pd Multilayers with Coherent X-ray Scattering

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Benny

    2012-04-05

    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.

  20. INTEGRAL monitoring of the X-ray burster XTE J1739-285

    DEFF Research Database (Denmark)

    Sánchez-Fernández, C.; Kuulkers, E.; Chenevez, Jérôme;

    2008-01-01

    XTE J1739-285 is a recurrent X-ray transient first discovered by INTEGRAL as an X-ray burster. We have carried out a systematic search for X-ray bursts at various levels of accretion rate onto the Neutron Star surface during the source outbursts in 2005 and 2006. A total of 25 X-ray bursts were f...

  1. Pump-flow-probe x-ray absorption spectroscopy as a tool for studying aintermediate states of photocatalytic systems

    DEFF Research Database (Denmark)

    Smolentsev, Grigory; Guda, Alexander; Zhang, Xiaoyi

    2013-01-01

    A new setup for pump-flow-probe X-ray absorption spectroscopy has been implemented at the SuperXAS beamline of the Swiss Light Source. It allows recording X-ray absorption spectra with a time resolution of tens of microseconds and high detection efficiency for samples with sub-millimolar concentr......A new setup for pump-flow-probe X-ray absorption spectroscopy has been implemented at the SuperXAS beamline of the Swiss Light Source. It allows recording X-ray absorption spectra with a time resolution of tens of microseconds and high detection efficiency for samples with sub......-millimolar concentrations. A continuous wave laser is used for the photoexcitation, with the distance between laser and X-ray beams and velocity of liquid flow determining the time delay, while the focusing of both beams and the flow speed profile define the time resolution. This method is compared with the alternative...... measurement technique that utilizes a 1 kHz repetition rate laser and multiple X-ray probe pulses. Such an experiment was performed at beamline 11ID-D of the Advanced Photon Source. Advantages, limitations, and potential for improvement of the pump-flow-probe setup are discussed by analyzing the photon...

  2. A Correlation between the Intrinsic Brightness and Average Decay Rate of Gamma-Ray Burst X-Ray Afterglow Light Curves

    Science.gov (United States)

    Racusin, J. L.; Oates, S. R.; de Pasquale, M.; Kocevski, D.

    2016-07-01

    We present a correlation between the average temporal decay ({α }{{X},{avg},\\gt 200{{s}}}) and early-time luminosity ({L}{{X},200{{s}}}) of X-ray afterglows of gamma-ray bursts as observed by the Swift X-ray Telescope. Both quantities are measured relative to a rest-frame time of 200 s after the γ-ray trigger. The luminosity-average decay correlation does not depend on specific temporal behavior and contains one scale-independent quantity minimizing the role of selection effects. This is a complementary correlation to that discovered by Oates et al. in the optical light curves observed by the Swift Ultraviolet Optical Telescope. The correlation indicates that, on average, more luminous X-ray afterglows decay faster than less luminous ones, indicating some relative mechanism for energy dissipation. The X-ray and optical correlations are entirely consistent once corrections are applied and contamination is removed. We explore the possible biases introduced by different light-curve morphologies and observational selection effects, and how either geometrical effects or intrinsic properties of the central engine and jet could explain the observed correlation.

  3. Resistive Wall Heating of the Undulator in High Repetition Rate

    Energy Technology Data Exchange (ETDEWEB)

    Qiang, J; Corlett, J; Emma, P; Wu, J

    2012-05-20

    In next generation high repetition rate FELs, beam energy loss due to resistive wall wakefields will produce significant amount of heat. The heat load for a superconducting undulator (operating at low temperature), must be removed and will be expensive to remove. In this paper, we study this effect in an undulator proposed for a Next Generation Light Source (NGLS) at LBNL. We benchmark our calculations with measurements at the LCLS and carry out detailed parameter studies using beam from a start-to-end simulation. Our preliminarym results suggest that the heat load in the undulator is about 2 W/m or lower with an aperture size of 6 mm for nominal NGLS preliminary design parameters.

  4. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... clothing that might interfere with the x-ray images. Women should always inform their physician and x-ray ... small burst of radiation that passes through the body, recording an image on photographic film or a special detector. Different ...

  5. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... bone absorbs much of the radiation while soft tissue, such as muscle, fat and organs, allow more of the x-rays to pass through them. As a result, bones appear white on the x-ray, soft tissue shows up in shades of gray and air ...

  6. Sixteen years of X-ray monitoring of Sagittarius A*: Evidence for a decay of the faint flaring rate from 2013 August, 13 months before a rise in the bright flaring rate

    Science.gov (United States)

    Mossoux, Enmanuelle; Grosso, Nicolas

    2017-08-01

    Context. X-ray flaring activity from the closest supermassive black hole Sagittarius A* (Sgr A*) located at the center of our Galaxy has been observed since 2000 October 26 thanks to the current generation of X-ray facilities. In a study of X-ray flaring activity from Sgr A* using Chandra and XMM-Newton public observations from 1999 to 2014 and Swift monitoring in 2014, it was argued that the "bright and very bright" flaring rate has increased from 2014 August 31. Aims: As a result of additional observations performed in 2015 with Chandra, XMM-Newton, and Swift (total exposure of 482 ks), we seek to test the significance and persistence of this increase of flaring rate and to determine the threshold of unabsorbed flare flux or fluence leading to any change of flaring rate. Methods: We reprocessed the Chandra, XMM-Newton, and Swift data from 1999 to 2015 November 2. From these data, we detected the X-ray flares via our two-step Bayesian blocks algorithm with a prior on the number of change points properly calibrated for each observation. We improved the Swift data analysis by correcting the effects of the target variable position on the detector and we detected the X-ray flares with a 3σ threshold on the binned light curves. The mean unabsorbed fluxes of the 107 detected flares were consistently computed from the extracted spectra and the corresponding calibration files, assuming the same spectral parameters. We constructed the observed distribution of flare fluxes and durations from the XMM-Newton and Chandra detections. We corrected this observed distribution from the detection biases to estimate the intrinsic distribution of flare fluxes and durations. From this intrinsic distribution, we determined the average flare detection efficiency for each XMM-Newton, Chandra, and Swift observation. We finally applied the Bayesian blocks algorithm on the arrival times of the flares corrected from the corresponding efficiency. Results: We confirm a constant overall flaring

  7. Optimizing x-ray mirror thermal performance using variable length cooling for second generation FELs

    Science.gov (United States)

    Hardin, Corey L.; Srinivasan, Venkat N.; Amores, Lope; Kelez, Nicholas M.; Morton, Daniel S.; Stefan, Peter M.; Nicolas, Josep; Zhang, Lin; Cocco, Daniele

    2016-09-01

    The success of the LCLS led to an interest across a number of disciplines in the scientific community including physics, chemistry, biology, and material science. Fueled by this success, SLAC National Accelerator Laboratory is developing a new high repetition rate free electron laser, LCLS-II, a superconducting linear accelerator capable of a repetition rate up to 1 MHz. Undulators will be optimized for 200 to 1300 eV soft X-rays, and for 1000 to 5000 eV hard X-rays. To absorb spontaneous radiation, higher harmonic energies and deflect the x-ray beam to various end stations, the transport and diagnostics system includes grazing incidence plane mirrors on both the soft and Hard X-ray beamline. To deliver the FEL beam with minimal power loss and wavefront distortion, we need mirrors of height errors below 1nm rms in operational conditions. We need to mitigate the thermal load effects due to the high repetition rate. The absorbed thermal profile is highly dependent on the beam divergence, and this is a function of the photon energy. To address this complexity, we developed a mirror cradle with variable length cooling and first order curve correction. Mirror figure error is minimized using variable length water-cooling through a gallium-indium eutectic bath. Curve correction is achieved with an off-axis bender that will be described in details. We present the design features, mechanical analysis and results from optical and mechanical tests of a prototype assembly, with particular regards to the figure sensitivity to bender corrections.

  8. Focusing X-Ray Telescopes

    Science.gov (United States)

    O'Dell, Stephen; Brissenden, Roger; Davis, William; Elsner, Ronald; Elvis, Martin; Freeman, Mark; Gaetz, Terrance; Gorenstein, Paul; Gubarev, Mikhall; Jerlus, Diab; Juda, Michael; Kolodziejczak, Jeffrey; Murray, Stephen; Petre, Robert; Podgorski, William; Ramsey, Brian; Reid, Paul; Saha, Timo; Wolk, Scott; Troller-McKinstry, Susan; Weisskopf, Martin; Wilke, Rudeger; Zhang, William

    2010-01-01

    During the half-century history of x-ray astronomy, focusing x-ray telescopes, through increased effective area and finer angular resolution, have improved sensitivity by 8 orders of magnitude. Here, we review previous and current x-ray-telescope missions. Next, we describe the planned next-generation x-ray-astronomy facility, the International X-ray Observatory (IXO). We conclude with an overview of a concept for the next next-generation facility, Generation X. Its scientific objectives will require very large areas (about 10,000 sq m) of highly-nested, lightweight grazing-incidence mirrors, with exceptional (about 0.1-arcsec) resolution. Achieving this angular resolution with lightweight mirrors will likely require on-orbit adjustment of alignment and figure.

  9. X-Ray Tomographic Reconstruction

    Energy Technology Data Exchange (ETDEWEB)

    Bonnie Schmittberger

    2010-08-25

    Tomographic scans have revolutionized imaging techniques used in medical and biological research by resolving individual sample slices instead of several superimposed images that are obtained from regular x-ray scans. X-Ray fluorescence computed tomography, a more specific tomography technique, bombards the sample with synchrotron x-rays and detects the fluorescent photons emitted from the sample. However, since x-rays are attenuated as they pass through the sample, tomographic scans often produce images with erroneous low densities in areas where the x-rays have already passed through most of the sample. To correct for this and correctly reconstruct the data in order to obtain the most accurate images, a program employing iterative methods based on the inverse Radon transform was written. Applying this reconstruction method to a tomographic image recovered some of the lost densities, providing a more accurate image from which element concentrations and internal structure can be determined.

  10. X-Ray Diffraction Apparatus

    Science.gov (United States)

    Blake, David F. (Inventor); Bryson, Charles (Inventor); Freund, Friedmann (Inventor)

    1996-01-01

    An x-ray diffraction apparatus for use in analyzing the x-ray diffraction pattern of a sample is introduced. The apparatus includes a beam source for generating a collimated x-ray beam having one or more discrete x-ray energies, a holder for holding the sample to be analyzed in the path of the beam, and a charge-coupled device having an array of pixels for detecting, in one or more selected photon energy ranges, x-ray diffraction photons produced by irradiating such a sample with said beam. The CCD is coupled to an output unit which receives input information relating to the energies of photons striking each pixel in the CCD, and constructs the diffraction pattern of photons within a selected energy range striking the CCD.

  11. X-ray monitoring optical elements

    Energy Technology Data Exchange (ETDEWEB)

    Stoupin, Stanislav; Shvydko, Yury; Katsoudas, John; Blank, Vladimir D.; Terentyev, Sergey A.

    2016-12-27

    An X-ray article and method for analyzing hard X-rays which have interacted with a test system. The X-ray article is operative to diffract or otherwise process X-rays from an input X-ray beam which have interacted with the test system and at the same time provide an electrical circuit adapted to collect photoelectrons emitted from an X-ray optical element of the X-ray article to analyze features of the test system.

  12. X-ray diagnostics for TFTR

    Energy Technology Data Exchange (ETDEWEB)

    von Goeler, S.; Hill, K.W.; Bitter, M.

    1982-12-01

    A short description of the x-ray diagnostic preparation for the TFTR tokamak is given. The x-ray equipment consists of the limiter x-ray monitoring system, the soft x-ray pulse-height-analysis-system, the soft x-ray imaging system and the x-ray crystal spectrometer. Particular attention is given to the radiation protection of the x-ray systems from the neutron environment.

  13. Multi-mJ, kHz, 2.1-$\\mu$m OPCPA for high-flux soft X-ray high-harmonic radiation

    CERN Document Server

    Hong, Kyung-Han; Siqueira, Jonathas; Krogen, Peter; Moses, Jeffrey; Smrz, Martin; Zapata, Luis E; Kärtner, Franz X

    2013-01-01

    We report on a multi-mJ 2.1-$\\mu$m OPCPA system operating at a 1-kHz repetition rate, pumped by a picosecond cryogenic Yb:YAG pump laser, and the phase-matched high-flux high-harmonic soft X-ray generation.

  14. In situ monitoring of laser-induced periodic surface structures formation on polymer films by grazing incidence small-angle X-ray scattering

    NARCIS (Netherlands)

    Rebollar, Esther; Rueda, Daniel R; Martín-Fabiani, Ignacio; Rodríguez-Rodríguez, Álvaro; García-Gutiérrez, Mari-Cruz; Portale, Giuseppe; Castillejo, Marta; Ezquerra, Tiberio A

    2015-01-01

    The formation of laser-induced periodic surface structures (LIPSS) on model spin-coated polymer films has been followed in situ by grazing incidence small-angle X-ray scattering (GISAXS) using synchrotron radiation. The samples were irradiated at different repetition rates ranging from 1 up to 10 Hz

  15. Solvation dynamics monitored by combined X-ray spectroscopies and scattering: photoinduced spin transition in aqueous [Fe(bpy)3]2+

    DEFF Research Database (Denmark)

    Bressler, C.; Gawelda, W.; Galler, A.;

    2014-01-01

    We have studied the photoinduced low spin (LS) to high spin (HS) conversion of aqueous Fe(bpy)3 with pulse-limited time resolution. In a combined setup permitting simultaneous X-ray diffuse scattering (XDS) and spectroscopic measurements at a MHz repetition rate we have unraveled the interplay be...

  16. The Cambridge-Cambridge X-ray Serendipity Survey: I X-ray luminous galaxies

    Science.gov (United States)

    Boyle, B. J.; Mcmahon, R. G.; Wilkes, B. J.; Elvis, M.

    1994-01-01

    We report on the first results obtained from a new optical identification program of 123 faint X-ray sources with S(0.5-2 keV) greater than 2 x 10(exp -14) erg/s/sq cm serendipitously detected in ROSAT PSPC pointed observations. We have spectroscopically identified the optical counterparts to more than 100 sources in this survey. Although the majority of the sample (68 objects) are QSO's, we have also identified 12 narrow emission line galaxies which have extreme X-ray luminosities (10(exp 42) less than L(sub X) less than 10(exp 43.5) erg/s). Subsequent spectroscopy reveals them to be a mixture of star-burst galaxies and Seyfert 2 galaxies in approximately equal numbers. Combined with potentially similar objects identified in the Einstein Extended Medium Sensitivity Survey, these X-ray luminous galaxies exhibit a rate of cosmological evolution, L(sub X) varies as (1 + z)(exp 2.5 +/- 1.0), consistent with that derived for X-ray QSO's. This evolution, coupled with the steep slope determined for the faint end of the X-ray luminosity function (Phi(L(sub X)) varies as L(sub X)(exp -1.9)), implies that such objects could comprise 15-35% of the soft (1-2 keV) X-ray background.

  17. Semiconductor X-ray detectors

    CERN Document Server

    Lowe, Barrie Glyn

    2014-01-01

    Identifying and measuring the elemental x-rays released when materials are examined with particles (electrons, protons, alpha particles, etc.) or photons (x-rays and gamma rays) is still considered to be the primary analytical technique for routine and non-destructive materials analysis. The Lithium Drifted Silicon (Si(Li)) X-Ray Detector, with its good resolution and peak to background, pioneered this type of analysis on electron microscopes, x-ray fluorescence instruments, and radioactive source- and accelerator-based excitation systems. Although rapid progress in Silicon Drift Detectors (SDDs), Charge Coupled Devices (CCDs), and Compound Semiconductor Detectors, including renewed interest in alternative materials such as CdZnTe and diamond, has made the Si(Li) X-Ray Detector nearly obsolete, the device serves as a useful benchmark and still is used in special instances where its large, sensitive depth is essential. Semiconductor X-Ray Detectors focuses on the history and development of Si(Li) X-Ray Detect...

  18. Properties and Applications of Laser Generated X-Ray Sources

    Energy Technology Data Exchange (ETDEWEB)

    Smith, R F; Key, M H

    2002-02-25

    The rapid development of laser technology and related progress in research using lasers is shifting the boundaries where laser based sources are preferred over other light sources particularly in the XUV and x-ray spectral region. Laser based sources have exceptional capability for short pulse and high brightness and with improvements in high repetition rate pulsed operation, such sources are also becoming more interesting for their average power capability. This study presents an evaluation of the current capabilities and near term future potential of laser based light sources and summarizes, for the purpose of comparison, the characteristics and near term prospects of sources based on synchrotron radiation and free electron lasers. Conclusions are drawn on areas where the development of laser based sources is most promising and competitive in terms of applications potential.

  19. A practical method to generate brilliant hard x-rays with a tabletop electron storage ring

    Energy Technology Data Exchange (ETDEWEB)

    Yamada, H. [Ritsumeikan Univ., Shiga (Japan); Amano, D.; Miyade, H. [Sumitomo Heavy Industries, Ltd., Tanashi-City (Japan)

    1995-12-31

    With electron storage rings not only synchrotron radiation(SR) but also bremsstrahlung(BS) from a thin target placed in the electron orbit are mechanisms to generate brilliant x-ray beams. The calculated brilliance of BS with a 50 MeV storage ring, which is nearly 10{sup 13} photons/s, mrad{sup 2}, mm{sup 2}, 0.1% band width for 100 keV x-rays, exceeds that of SR from a 1 GeV storage ring. This photon energy spectrum is almost constant and extend up to the electron energy. The reasons for this high brilliance with this new radiation scheme is that the electron beams penetrating the thin target are utilized repeatedly, the narrow angular divergence of BS is determined by the kinematics of relativistic electron as same as SR, and the x-ray source size of the order of 1 {mu}m is determined by the size of thin target instead of electron beam sizes. Continuous injection of electron beam to the storage ring at full energy is the way to keep high and constant beam current. Peak current and repetition rate determine x-ray out put power. Note that the power of x-ray beam is also provided from a RF cavity of the storage ring. In this paper we will report some experimental results and discuss further application on a coherent bremsstrahlung generated from a set of stacked foils placed in the electron orbit of the ring. Resulting from these investigations the photon storage ring which is based on a 50 MeV exact circular electron storage ring could provide wide range of coherent and incoherent radiations from far infrared to hard x-ray in a practical amount of radiation power.

  20. Improved performances of CIBER-X: a new tabletop laser-driven electron and x-ray source

    Science.gov (United States)

    Girardeau-Montaut, Jean-Pierre; Kiraly, Bela; Girardeau-Montaut, Claire

    2000-11-01

    We present the most recent data concerning the performances of the table-top laser driven electron and x-ray source developed in our laboratory. X-ray pulses are produced by a three-step process which consists of the photoelectron emission from a thin metallic photocathode illuminated by 16 ps duration laser pulse at 213 nm. The e-gun is a standard pierce diode electrode type, in which electrons are accelerated by a cw electric fields of 12 MV/m. The photoinjector produced a train of 90 - 100 keV electron pulses of approximately 1 nC and 40 A peak current at a repetition rate of 10 Hz. The electrons, transported outside the diode, are focused onto a target of thulium by magnetic fields produced by two electromagnetic coils to produce x-rays. Applications to low dose imagery of inert and living materials are also presented.

  1. Experimental station for laser-based picosecond time-resolved x-ray absorption near-edge spectroscopy

    Science.gov (United States)

    Dorchies, F.; Fedorov, N.; Lecherbourg, L.

    2015-07-01

    We present an experimental station designed for time-resolved X-ray Absorption Near-Edge Spectroscopy (XANES). It is based on ultrashort laser-plasma x-ray pulses generated from a table-top 100 mJ-class laser at 10 Hz repetition rate. A high transmission (10%-20%) x-ray beam line transport using polycapillary optics allows us to set the sample in an independent vacuum chamber, providing high flexibility over a wide spectral range from 0.5 up to 4 keV. Some XANES spectra are presented, demonstrating 1% noise level in only ˜1 mn and ˜100 cumulated laser shots. Time-resolved measurements are reported, indicating that the time resolution of the entire experimental station is 3.3 ± 0.6 ps rms.

  2. Experimental station for laser-based picosecond time-resolved x-ray absorption near-edge spectroscopy.

    Science.gov (United States)

    Dorchies, F; Fedorov, N; Lecherbourg, L

    2015-07-01

    We present an experimental station designed for time-resolved X-ray Absorption Near-Edge Spectroscopy (XANES). It is based on ultrashort laser-plasma x-ray pulses generated from a table-top 100 mJ-class laser at 10 Hz repetition rate. A high transmission (10%-20%) x-ray beam line transport using polycapillary optics allows us to set the sample in an independent vacuum chamber, providing high flexibility over a wide spectral range from 0.5 up to 4 keV. Some XANES spectra are presented, demonstrating 1% noise level in only ∼1 mn and ∼100 cumulated laser shots. Time-resolved measurements are reported, indicating that the time resolution of the entire experimental station is 3.3 ± 0.6 ps rms.

  3. Experimental station for laser-based picosecond time-resolved x-ray absorption near-edge spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Dorchies, F., E-mail: dorchies@celia.u-bordeaux1.fr; Fedorov, N.; Lecherbourg, L. [Université Bordeaux, CNRS, CEA, CELIA (Centre Lasers Intenses et Applications), UMR 5107, Talence F-33405 (France)

    2015-07-15

    We present an experimental station designed for time-resolved X-ray Absorption Near-Edge Spectroscopy (XANES). It is based on ultrashort laser-plasma x-ray pulses generated from a table-top 100 mJ-class laser at 10 Hz repetition rate. A high transmission (10%–20%) x-ray beam line transport using polycapillary optics allows us to set the sample in an independent vacuum chamber, providing high flexibility over a wide spectral range from 0.5 up to 4 keV. Some XANES spectra are presented, demonstrating 1% noise level in only ∼1 mn and ∼100 cumulated laser shots. Time-resolved measurements are reported, indicating that the time resolution of the entire experimental station is 3.3 ± 0.6 ps rms.

  4. Outbursts in ultracompact X-ray binaries

    CERN Document Server

    Hameury, J -M

    2016-01-01

    Very faint X-ray binaries appear to be transient in many cases with peak luminosities much fainter than that of usual soft X-ray transients, but their nature still remains elusive. We investigate the possibility that this transient behaviour is due to the same thermal/viscous instability which is responsible for outbursts of bright soft X-ray transients, occurring in ultracompact binaries for adequately low mass-transfer rates. More generally, we investigate the observational consequences of this instability when it occurs in ultracompact binaries. We use our code for modelling the thermal-viscous instability of the accretion disc, assumed here to be hydrogen poor. We also take into account the effects of disc X-ray irradiation, and consider the impact of the mass-transfer rate on the outburst brightness. We find that one can reproduce the observed properties of both the very faint and the brighter short transients (peak luminosity, duration, recurrence times), provided that the viscosity parameter in quiesce...

  5. Luminescence properties after X-ray irradiation for dosimetry

    Science.gov (United States)

    Hong, Duk-Geun; Kim, Myung-Jin

    2016-05-01

    To investigate the luminescence characteristics after exposure to X-ray radiation, we developed an independent, small X-ray irradiation system comprising a Varian VF-50J mini X-ray generator, a Pb collimator, a delay shutter, and an Al absorber. With this system, the apparent dose rate increased linearly to 0.8 Gy/s against the emission current for a 50 kV anode potential when the shutter was delayed for an initial 4 s and the Al absorber was 300 µm thick. In addition, an approximately 20 mm diameter sample area was irradiated homogeneously with X rays. Based on three-dimensional (3D) thermoluminescence (TL) spectra, the small X-ray irradiator was considered comparable to the conventional 90Sr/90Y beta source even though the TL intensity from beta irradiation was higher than that from X-ray irradiation. The single aliquot regenerative (SAR) growth curve for the small X-ray irradiator was identical to that for the beta source. Therefore, we concluded that the characteristics of the small X-ray irradiator and the conventional 90Sr/90Y beta source were similar and that X ray irradiation had the potential for being suitable for use in luminescence dosimetry.

  6. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... during x-ray examinations to use the lowest radiation dose possible while producing the best images for evaluation. National and international radiology protection organizations continually review ...

  7. Bone X-Ray (Radiography)

    Science.gov (United States)

    ... bony fragments following treatment of a fracture. guide orthopedic surgery, such as spine repair/fusion, joint replacement ... A portable x-ray machine is a compact apparatus that can be taken to the patient in ...

  8. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... the oldest and most frequently used form of medical imaging. A bone x-ray makes images of any ... a radiologist or other physician. To locate a medical imaging or radiation oncology provider in your community, you ...

  9. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... replacement and fracture reductions. look for injury, infection, arthritis , abnormal bone growths and bony changes seen in ... injuries, including fractures, and joint abnormalities, such as arthritis. X-ray equipment is relatively inexpensive and widely ...

  10. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... top of page What are the benefits vs. risks? Benefits Bone x-rays are the fastest and ... in the typical diagnostic range for this exam. Risks There is always a slight chance of cancer ...

  11. CELESTIAL X-RAY SOURCES.

    Science.gov (United States)

    sources, (4) the physical conditions in the pulsating x-ray source in the Crab Nebula , and (5) miscellaneous related topics. A bibliography of all work performed under the contract is given. (Author)

  12. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... asked to wait until the radiologist determines that all the necessary images have been obtained. A bone ... while it may be barely seen, if at all, on a hip x-ray. For suspected spine ...

  13. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... patients and physicians. Because x-ray imaging is fast and easy, it is particularly useful in emergency ... diagnosis and treatment of the individual patient's condition. Ultrasound imaging, which uses sound waves instead of ionizing ...

  14. X-Ray Assembler Data

    Data.gov (United States)

    U.S. Department of Health & Human Services — Federal regulations require that an assembler who installs one or more certified components of a diagnostic x-ray system submit a report of assembly. This database...

  15. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... a form of radiation like light or radio waves. X-rays pass through most objects, including the ... individual patient's condition. Ultrasound imaging, which uses sound waves instead of ionizing radiation to create diagnostic images, ...

  16. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... pregnant. Many imaging tests are not performed during pregnancy so as not to expose the fetus to ... See the Safety page for more information about pregnancy and x-rays. top of page What does ...

  17. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... are easily accessible and are frequently compared to current x-ray images for diagnosis and disease management. ... of North America, Inc. (RSNA). To help ensure current and accurate information, we do not permit copying ...

  18. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... ionizing radiation to produce pictures of any bone in the body. It is commonly used to diagnose ... bone x-ray makes images of any bone in the body, including the hand, wrist, arm, elbow, ...

  19. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... current x-ray images for diagnosis and disease management. top of page How is the procedure performed? ... examination may also be necessary so that any change in a known abnormality can be monitored over ...

  20. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... patients and physicians. Because x-ray imaging is fast and easy, it is particularly useful in emergency ... 06, 2016 Send us your feedback Did you find the information you were looking for? Yes No ...

  1. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... in emergency rooms, physician offices, ambulatory care centers, nursing homes and other locations, making it convenient for ... Safety page for more information about radiation dose. Women should always inform their physician or x-ray ...

  2. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... evaluation with additional views or a special imaging technique. A follow-up examination may also be necessary ... radiology protection organizations continually review and update the technique standards used by radiology professionals. Modern x-ray ...

  3. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... x-ray images were maintained on large film sheets (much like a large photographic negative). Today, most ... accredited facilities database . This website does not provide cost information. The costs for specific medical imaging tests, ...

  4. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... x-ray machine is a compact apparatus that can be taken to the patient in a hospital ... so that any change in a known abnormality can be monitored over time. Follow-up examinations are ...

  5. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... current x-ray images for diagnosis and disease management. top of page How is the procedure performed? ... in a known abnormality can be monitored over time. Follow-up examinations are sometimes the best way ...

  6. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... for more information about pregnancy and x-rays. A Word About Minimizing Radiation Exposure Special care is ... code: Phone no: Thank you! Do you have a personal story about radiology? Share your patient story ...

  7. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... current x-ray images for diagnosis and disease management. top of page How is the procedure performed? ... these links. About Us | Contact Us | FAQ | Privacy | Terms of Use | Links | Site Map Copyright © 2017 Radiological ...

  8. Characteristics of changes in the number of yH2AX and Rad51 protein foci in human skin fibroblasts after prolonged exposure to low-dose rate X-ray radiation

    Directory of Open Access Journals (Sweden)

    Ozerov I.V.

    2014-12-01

    Full Text Available Aim: to compare the repair process of DNA double-strand breaks in mammalian cells after acute versus prolonged exposure to X-ray irradiation with different dose rates. Material and methods. Studies were performed on primary human fibroblasts isolated from skin biopsies of healthy volunteers (women, 29 and 30 years. Cells were irradiated using an X-ray machine RUB RUST-M1 (JSC "Ruselectronics", Moscow, Russia at 37°C temperature with a dose rate of 400 mGy/min (200 kV, 2*2.4 mA, a filter of 1.5mm AI or 4 mGy/min (50 kV, 2*0.4 mA, a filter of 1.5 mm AI. Immuno-cytochemical protein staining was utilized for yH2AX and Rad51 foci analysis. Results. Phosphorylated histone H2AX (yH2AX and the key protein of homologous recombination Rad51 foci formation and disappearance kinetics were investigated simultaneously in primary human dermal fibroblasts after acute and prolonged exposure to X-ray radiation at a same dose. It was shown that the relative yield of yH2AX foci per dose reduces with decrease in dose rate, while the relative yield of Rad51 foci conversely increases. Conclusion. Our findings suggest the fundamental differences in the ratio of non-homologous end joining and homologous recombination DNA repair in acute versus prolonged irradiated cells.

  9. Electromechanical x-ray generator

    Energy Technology Data Exchange (ETDEWEB)

    Watson, Scott A; Platts, David; Sorensen, Eric B

    2016-05-03

    An electro-mechanical x-ray generator configured to obtain high-energy operation with favorable energy-weight scaling. The electro-mechanical x-ray generator may include a pair of capacitor plates. The capacitor plates may be charged to a predefined voltage and may be separated to generate higher voltages on the order of hundreds of kV in the AK gap. The high voltage may be generated in a vacuum tube.

  10. Accelerator x-ray sources

    CERN Document Server

    Talman, Richard

    2007-01-01

    This first book to cover in-depth the generation of x-rays in particle accelerators focuses on electron beams produced by means of the novel Energy Recovery Linac (ERL) technology. The resulting highly brilliant x-rays are at the centre of this monograph, which continues where other books on the market stop. Written primarily for general, high energy and radiation physicists, the systematic treatment adopted by the work makes it equally suitable as an advanced textbook for young researchers.

  11. X-ray fluorescence holography

    CERN Document Server

    Hayashi, K; Takahashi, Y

    2003-01-01

    X-ray fluorescence holography (XFH) is a new structural analysis method of determining a 3D atomic arrangement around fluorescing atoms. We developed an XFH apparatus using advanced X-ray techniques and succeeded in obtaining high-quality hologram data. Furthermore, we introduced applications to the structural analysis of a thin film and the environment around dopants and, discussed the quantitative analysis of local lattice distortion. (author)

  12. X-ray Sensitive Material

    Science.gov (United States)

    2015-12-01

    these published reports. There were two main types of X-ray detection methods: “indirect,” which uses a scintillation material coupled to a light...Reference 3), inorganic semiconductors (silicon [Si], cadmium zinc telluride [CdZnTe]) (Reference 4) and selenium (References 5 and 6), Ne-Xe...metal-oxide semiconductor field-effect transistor (MOSFET) X-ray dosimeters (Reference 24). Electrets may be charged by a range of methods

  13. Building lab-scale x-ray tube based irradiators

    Science.gov (United States)

    The construction of economical x-ray tube based irradiators in a variety of configurations is described using 1000 Watt x-ray tubes. Single tube, double tube, and four tube designs are described, as well as various cabinet construction techniques. Relatively high dose rates were achieved for small s...

  14. Development of an ultrashort table-top electron and x-ray source pumped by laser

    Science.gov (United States)

    Girardeau-Montaut, Jean-Pierre; Kiraly, Bela; Girardeau-Montaut, Claire; Leboutet, Hubert

    1999-09-01

    We report on the design of the CIBER-X source which is a new laser driven table-top ultrashort electron and x-ray source. X-ray pulses are produced by a three-step process which consists of the electron pulse production from a thin metallic photocathode illuminated by picosecond 213 nm laser pulses with 16 ps duration. The electrons are accelerated in the diode by a cw electric field of 11 MV/m, and the photoinjector produces a single 70 - 100 keV electron pulse of approximately 0,5 nC and approximately 20 A peak current at a repetition rate of 10 Hz. The gun is a standard Pierce diode electrode type, the electrons leaving the diode through a hole made in the anode. The electrons are then transported along a path approximately 20 cm long, and are focused by two magnetic fields produced by electromagnetic coils. Finally, the x-rays are produced by the impact of electrons on a massive target of Tm. Simulations of geometrical and energetic characteristics of the complete source were done previously with assistance of the code PIXEL1. Finally, experimental performances of electron and x-ray bursts are discussed.

  15. Toward picosecond time-resolved X-ray absorption studies of interfacial photochemistry

    Science.gov (United States)

    Gessner, Oliver; Mahl, Johannes; Neppl, Stefan

    2016-05-01

    We report on the progress toward developing a novel picosecond time-resolved transient X-ray absorption spectroscopy (TRXAS) capability for time-domain studies of interfacial photochemistry. The technique is based on the combination of a high repetition rate picosecond laser system with a time-resolved X-ray fluorescent yield setup that may be used for the study of radiation sensitive materials and X-ray spectroscopy compatible photoelectrochemical (PEC) cells. The mobile system is currently deployed at the Advanced Light Source (ALS) and may be used in all operating modes (two-bunch and multi-bunch) of the synchrotron. The use of a time-stamping technique enables the simultaneous recording of TRXAS spectra with delays between the exciting laser pulses and the probing X-ray pulses spanning picosecond to nanosecond temporal scales. First results are discussed that demonstrate the viability of the method to study photoinduced dynamics in transition metal-oxide semiconductor (SC) samples under high vacuum conditions and at SC-liquid electrolyte interfaces during photoelectrochemical water splitting. Opportunities and challenges are outlined to capture crucial short-lived intermediates of photochemical processes with the technique. This work was supported by the Department of Energy Office of Science Early Career Research Program.

  16. High-Energy Density science with an ultra-bright x-ray laser

    Science.gov (United States)

    Glenzer, Siegfried

    2015-11-01

    This talk will review recent progress in high-energy density physics using the world's brightest x-ray source, the Linac Coherent Light Source, SLAC's free electron x-ray laser. These experiments investigate laser-driven matter in extreme conditions where powerful x-ray scattering and imaging techniques have been applied to resolve ionic interactions at atomic (Ångstrom) scale lengths and to visualize the formation of dense plasma states. Major research areas include dynamic compression experiments of solid targets to determine structural properties and to discover and characterize phase transitions at mega-bar pressures. A second area studies extreme fields produced by high-intensity radiation where fundamental questions of laboratory plasmas can be related to cosmological phenomena. Each of these areas takes advantage of the unique properties of the LCLS x-ray beam. They include small foci for achieving high intensity or high spatial resolution, high photon flux for dynamic structure factor measurements in single shots, and high spectral bandwidth to resolve plasmon (Langmuir) waves or ion acoustic waves in dense plasmas. We will further describe new developments of ultrafast pump-probe technique at high repetition rates. These include studies on dense cryogenic hydrogen that have begun providing fundamental insights into the physical properties of matter in extreme conditions that are important for astrophysics, fusion experiments and generation of radiation sources. This work was supported by DOE Office of Science, Fusion Energy Science under FWP 100182.

  17. X-ray Radio Correlation In Black Hole Sources

    CERN Document Server

    Rao, A R

    2006-01-01

    We examine the X-ray - radio correlation in Galactic black hole sources. We highlight some of the results which extend the flux-flux relations to sources with very high accretion rates. Some of the recent results indicate that the synchrotron process is unlikely to be the mechanism responsible for the X-ray emission, particularly at high accretion rates. We present a truncated accretion disk scenario and argue that accretion rate and accretion disk geometry ultimately act as a driver of the X-ray - radio correlation. We stress the importance of wide-band X-ray spectral measurements to understand the disk-jet connection and briefly outline some attempts made in the Indian context to build instruments for wide-band X-ray spectroscopy.

  18. X-ray laser; Roentgenlaser

    Energy Technology Data Exchange (ETDEWEB)

    Samuelsen, Emil J.; Breiby, Dag W.

    2009-07-01

    X-ray is among the most important research tools today, and has given priceless contributions to all disciplines within the natural sciences. State of the art in this field is called XFEL, X-ray Free Electron Laser, which may be 10 thousand million times stronger than the x-rays at the European Synchrotron Radiation Facility in Grenoble. In addition XFEL has properties that allow the study of processes which previously would have been impossible. Of special interest are depictions on atomic- and molecular level by the use of x-ray holographic methods, and being able to study chemical reactions in nature's own timescale, the femtosecond. Conclusion: The construction of x-ray lasers is a natural development in a scientific field which has an enormous influence on the surrounding society. While the discovery of x-ray was an important breakthrough in itself, new applications appear one after the other: Medical depiction, dissemination, diffraction, DNA and protein structures, synchrotron radiation and tomography. There is reason to believe that XFEL implies a technological leap as big as the synchrotrons some decades ago. As we are now talking about studies of femtosecond and direct depiction of chemical reactions, it is obvious that we are dealing with a revolution to come, with extensive consequences, both scientifically and culturally. (EW)

  19. X-Rays, Pregnancy and You

    Science.gov (United States)

    ... and Procedures Medical Imaging Medical X-ray Imaging X-Rays, Pregnancy and You Share Tweet Linkedin Pin ... the decision with your doctor. What Kind of X-Rays Can Affect the Unborn Child? During most ...

  20. X-ray Photoevaporation-starved T Tauri Accretion

    CERN Document Server

    Drake, Jeremy J; Flaccomio, Ettore; Micela, Giusi

    2009-01-01

    X-ray luminosities of accreting T Tauri stars are observed to be systematically lower than those of non-accretors. There is as yet no widely accepted physical explanation for this effect, though it has been suggested that accretion somehow suppresses, disrupts or obscures coronal X-ray activity. Here, we suggest that the opposite might be the case: coronal X-rays modulate the accretion flow. We re-examine the X-ray luminosities of T Tauri stars in the Orion Nebula Cluster and find that not only are accreting stars systematically fainter, but that there is a correlation between mass accretion rate and stellar X-ray luminosity. We use the X-ray heated accretion disk models of Ercolano et al. to show that protoplanetary disk photoevaporative mass loss rates are strongly dependent on stellar X-ray luminosity and sufficiently high to be competitive with accretion rates. X-ray disk heating appears to offer a viable mechanism for modulating the gas accretion flow and could be at least partially responsible for the o...

  1. Growth rates and geochemical proxies in Late Campanian bivalves - New insights from micro-X-ray Fluorescence mapping and numerical growth modelling

    Science.gov (United States)

    de Winter, Niels; Goderis, Steven; van Malderen, Stijn; Vanhaecke, Frank; Claeys, Philippe

    2017-04-01

    Understanding the Late Cretaceous greenhouse climate is of vital importance for understanding present and future climate change. While a lot of good work has been done to reconstruct climate in this interesting period, most paleoclimatic studies have focused on long-term climate change[1]. Alternatively, multi-proxy records from marine bivalves provide us with a unique opportunity to study past climate on a seasonal scale. However, previous fossil bivalve studies have reported ambiguous results with regard to the interpretation of trace element and stable isotope proxies in marine bivalve shells[2]. One major problem in the interpretation of such records is the bivalve's vital effect and the occurrence of disequilibrium fractionation during bivalve growth. Both these problems are linked to the annual growth cycle of marine bivalves, which introduces internal effects on the incorporation of isotopes and trace elements into the shell[3]. Understanding this growth cycle in extinct bivalves is therefore of great importance for the interpretation of seasonal proxy records in their shells. In this study, three different species of extinct Late Campanian bivalves (two rudist species and one oyster species) that were found in the same stratigraphic interval are studied. Micro-X-Ray Fluorescence line scanning and mapping of trace elements such as Mg, Sr, S and Zn, calibrated by LA-ICP-MS measurements, is combined with microdrilled stable carbon and oxygen isotope analysis on the well-preserved part of the shells. Data of this multi-proxy study is compared with results from a numerical growth model written in the open-source statistics package R[4] and based on annual growth increments observed in the shells and shell thickness. This growth model is used together with proxy data to reconstruct rates of trace element incorporation into the shell and to calculate the mass balance of stable oxygen and carbon isotopes. In order to achieve this goal, 2D mapping of bivalve shell

  2. X-ray shout echoing through space

    Science.gov (United States)

    2004-01-01

    observatories around the world were pointing their instruments at this mysterious source in the sky, named GRB 031203, in the attempt to decipher its nature. Also ESA's X-ray observatory, XMM-Newton, joined the hunt and observed the source in detail, using its on-board European Photon Imaging Camera (EPIC). The fading X-ray emission from GRB 031203 - called the `afterglow' - is clearly seen in XMM-Newton's images. But much more stunning are the two rings, centred on the afterglow, which appear to expand thousand times faster than the speed of light. Dr. Simon Vaughan, of the University of Leicester, United Kingdom, leads an international team of scientists studying GRB 031203. He explains that these rings are what astronomers call an `echo'. They form when the X-rays from the distant gamma-ray burst shine on a layer of dust in our own Galaxy. "The dust scatters some of the X-rays, causing XMM-Newton to observe these rings, much in the same way as fog scatters the light from a car's headlights," said Vaughan. Although the afterglow is the brightest feature seen in XMM-Newton's images, the expanding echo is much more spectacular. "It is like a shout in a cathedral," Vaughan said. "The shout of the gamma-ray burst is louder, but the Galactic reverberation, seen as the rings, is much more beautiful." The rings seem to expand because the X-rays scattered by dust farther from the direction of GRB 031203 take longer to reach us than those hitting the dust closer to the line of sight. However, nothing can move faster than light. "This is precisely what we expect because of the finite speed of light," said Vaughan. "The rate of expansion that we see is just a visual effect." He and his colleagues explain that we see two rings because there are two thin sheets of dust between the source of the gamma-ray burst and Earth, one closer to us creating the wider ring and one further away where the smaller ring is formed. Since they know precisely at what speed the X-ray light travels in space

  3. Sorting algorithms for single-particle imaging experiments at X-ray free-electron lasers.

    Science.gov (United States)

    Bobkov, S A; Teslyuk, A B; Kurta, R P; Gorobtsov, O Yu; Yefanov, O M; Ilyin, V A; Senin, R A; Vartanyants, I A

    2015-11-01

    Modern X-ray free-electron lasers (XFELs) operating at high repetition rates produce a tremendous amount of data. It is a great challenge to classify this information and reduce the initial data set to a manageable size for further analysis. Here an approach for classification of diffraction patterns measured in prototypical diffract-and-destroy single-particle imaging experiments at XFELs is presented. It is proposed that the data are classified on the basis of a set of parameters that take into account the underlying diffraction physics and specific relations between the real-space structure of a particle and its reciprocal-space intensity distribution. The approach is demonstrated by applying principal component analysis and support vector machine algorithms to the simulated and measured X-ray data sets.

  4. BEAM OPTIMIZATION STUDY FOR AN X-RAY FEL OSCILLATOR AT THE LCLS-II

    Energy Technology Data Exchange (ETDEWEB)

    Qin, Weilun; Huang, S.; Liu, K.X.; Huang, Z; Ding, Y.; Maxwell, T.J.; Kim, K.-J.

    2016-06-01

    The 4 GeV LCLS-II superconducting linac with high repetition beam rate enables the possibility to drive an X-Ray FEL oscillator at harmonic frequencies *. Compared to the regular LCLS-II machine setup, the oscillator mode requires a much longer bunch length with a relatively lower current. Also a flat longitudinal phase space distribution is critical to maintain the FEL gain since the X-ray cavity has extremely narrow bandwidth. In this paper, we study the longitudinal phase space optimization including shaping the initial beam from the injector and optimizing the bunch compressor and dechirper parameters. We obtain a bunch with a flat energy chirp over 400 fs in the core part with current above 100 A. The optimization was based on LiTrack and Elegant simulations using LCLS-II beam parameters.

  5. Optimal main pulse angle for different preplasma conditions in transient collisionally pumped x-ray lasers.

    Science.gov (United States)

    Ursescu, Daniel; Zielbauer, Bernhard; Kuehl, Thomas; Neumayer, Paul; Pert, Geoff

    2007-04-01

    The effects of the incidence angle of the main pump (MP) pulse in non-normal pumping geometry and the influence of the MP duration are investigated experimentally and theoretically for a transient collisionally pumped (TCE) x-ray laser in Ni-like Zr at 45 degrees and 72 degrees incidence angle on the target. The way they transfer to the x-ray laser output depends on the preplasma conditions, most notably on the average ionization distribution at the arrival of the MP. Moreover, contrary to previous grazing incidence pumping results, it is found that the shortest attainable MP maximizes the output. Modeling of the experimental results is performed with EHYBRID code. The results are important for scaling high repetition-rate non-normal incidence pumped lasers to sub- 10nm wavelengths.

  6. X-ray computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Kalender, Willi A [Institute of Medical Physics, University Erlangen-Nuernberg, Henkestr. 91, D-91052 Erlangen (Germany)

    2006-07-07

    X-ray computed tomography (CT), introduced into clinical practice in 1972, was the first of the modern slice-imaging modalities. To reconstruct images mathematically from measured data and to display and to archive them in digital form was a novelty then and is commonplace today. CT has shown a steady upward trend with respect to technology, performance and clinical use independent of predictions and expert assessments which forecast in the 1980s that it would be completely replaced by magnetic resonance imaging. CT not only survived but exhibited a true renaissance due to the introduction of spiral scanning which meant the transition from slice-by-slice imaging to true volume imaging. Complemented by the introduction of array detector technology in the 1990s, CT today allows imaging of whole organs or the whole body in 5 to 20 s with sub-millimetre isotropic resolution. This review of CT will proceed in chronological order focussing on technology, image quality and clinical applications. In its final part it will also briefly allude to novel uses of CT such as dual-source CT, C-arm flat-panel-detector CT and micro-CT. At present CT possibly exhibits a higher innovation rate than ever before. In consequence the topical and most recent developments will receive the greatest attention. (review)

  7. X-ray induced photoacoustic tomography

    Science.gov (United States)

    Xiang, Liangzhong; Han, Bin; Carpenter, Colin; Pratx, Guillem; Kuang, Yu; Xing, Lei

    2013-03-01

    X-ray induced photoacoustic tomography, also called X-ray acoustic computer tomography (XACT) is investigated in this paper. Short pulsed (μs-range) X-ray beams from a medical linear accelerator were used to generate ultrasound. The ultrasound signals were collected with an ultrasound transducer (500 KHz central frequency) positioned around an object. The transducer, driven by a computer-controlled step motor to scan around the object, detected the resulting acoustic signals in the imaging plane at each scanning position. A pulse preamplifier, with a bandwidth of 20 KHz-2 MHz at -3 dB, and switchable gains of 40 and 60 dB, received the signals from the transducer and delivered the amplified signals to a secondary amplifier. The secondary amplifier had bandwidth of 20 KHz-30 MHz at -3 dB, and a gain range of 10-60 dB. Signals were recorded and averaged 128 times by an oscilloscope. A sampling rate of 100 MHz was used to record 2500 data points at each view angle. One set of data incorporated 200 positions as the receiver moved 360°. The x-ray generated acoustic image was then reconstructed with the filtered back projection algorithm. The twodimensional XACT images of the lead rod embedded in chicken breast tissue were found to be in good agreement with the shape of the object. This new modality may be useful for a number of applications, such as providing the location of a fiducial, or monitoring x-ray dose distribution during radiation therapy.

  8. Neutron and X-ray Detectors

    Energy Technology Data Exchange (ETDEWEB)

    Carini, Gabriella [SLAC National Accelerator Lab., Menlo Park, CA (United States); Denes, Peter [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Gruener, Sol [Cornell Univ., Ithaca, NY (United States); Lessner, Elianne [Dept. of Energy (DOE), Washington DC (United States). Office of Science Office of Basic Energy Sciences

    2012-08-01

    (and two computing hurdles that result from the corresponding increase in data volume) for the detector community to overcome in order to realize the full potential of BES neutron and X-ray facilities. Resolving these detector impediments will improve scientific productivity both by enabling new types of experiments, which will expand the scientific breadth at the X-ray and neutron facilities, and by potentially reducing the beam time required for a given experiment. These research priorities are summarized in the table below. Note that multiple, simultaneous detector improvements are often required to take full advantage of brighter sources. High-efficiency hard X-ray sensors: The fraction of incident particles that are actually detected defines detector efficiency. Silicon, the most common direct-detection X-ray sensor material, is (for typical sensor thicknesses) 100% efficient at 8 keV, 25%efficient at 20 keV, and only 3% efficient at 50 keV. Other materials are needed for hard X-rays. Replacement for 3He for neutron detectors: 3He has long been the neutron detection medium of choice because of its high cross section over a wide neutron energy range for the reaction 3He + n —> 3H + 1H + 0.764 MeV. 3He stockpiles are rapidly dwindling, and what is available can be had only at prohibitively high prices. Doped scintillators hold promise as ways to capture neutrons and convert them into light, although work is needed on brighter, more efficient scintillator solutions. Neutron detectors also require advances in speed and resolution. Fast-framing X-ray detectors: Today’s brighter X-ray sources make time-resolved studies possible. For example, hybrid X-ray pixel detectors, initially developed for particle physics, are becoming fairly mature X-ray detectors, with considerable development in Europe. To truly enable time-resolved studies, higher frame rates and dynamic range are required, and smaller pixel sizes are desirable. High-speed spectroscopic X-ray detectors

  9. X-ray Echo Spectroscopy

    Science.gov (United States)

    Shvyd'ko, Yuri

    2016-02-01

    X-ray echo spectroscopy, a counterpart of neutron spin echo, is being introduced here to overcome limitations in spectral resolution and weak signals of the traditional inelastic x-ray scattering (IXS) probes. An image of a pointlike x-ray source is defocused by a dispersing system comprised of asymmetrically cut specially arranged Bragg diffracting crystals. The defocused image is refocused into a point (echo) in a time-reversal dispersing system. If the defocused beam is inelastically scattered from a sample, the echo signal acquires a spatial distribution, which is a map of the inelastic scattering spectrum. The spectral resolution of the echo spectroscopy does not rely on the monochromaticity of the x rays, ensuring strong signals along with a very high spectral resolution. Particular schemes of x-ray echo spectrometers for 0.1-0.02 meV ultrahigh-resolution IXS applications (resolving power >108 ) with broadband ≃5 - 13 meV dispersing systems are introduced featuring more than 103 signal enhancement. The technique is general, applicable in different photon frequency domains.

  10. X-ray echo spectroscopy

    CERN Document Server

    Shvyd'ko, Yuri

    2015-01-01

    X-ray echo spectroscopy, a counterpart of neutron spin-echo, is being introduced here to overcome limitations in spectral resolution and weak signals of the traditional inelastic x-ray scattering (IXS) probes. An image of a point-like x-ray source is defocused by a dispersing system comprised of asymmetrically cut specially arranged Bragg diffracting crystals. The defocused image is refocused into a point (echo) in a time-reversal dispersing system. If the defocused beam is inelastically scattered from a sample, the echo signal acquires a spatial distribution, which is a map of the inelastic scattering spectrum. The spectral resolution of the echo spectroscopy does not rely on the monochromaticity of the x-rays, ensuring strong signals along with a very high spectral resolution. Particular schemes of x-ray echo spectrometers for 0.1--0.02-meV ultra-high-resolution IXS applications (resolving power $> 10^8$) with broadband $\\simeq$~5--13~meV dispersing systems are introduced featuring more than $10^3$ signal e...

  11. X-ray Echo Spectroscopy.

    Science.gov (United States)

    Shvyd'ko, Yuri

    2016-02-26

    X-ray echo spectroscopy, a counterpart of neutron spin echo, is being introduced here to overcome limitations in spectral resolution and weak signals of the traditional inelastic x-ray scattering (IXS) probes. An image of a pointlike x-ray source is defocused by a dispersing system comprised of asymmetrically cut specially arranged Bragg diffracting crystals. The defocused image is refocused into a point (echo) in a time-reversal dispersing system. If the defocused beam is inelastically scattered from a sample, the echo signal acquires a spatial distribution, which is a map of the inelastic scattering spectrum. The spectral resolution of the echo spectroscopy does not rely on the monochromaticity of the x rays, ensuring strong signals along with a very high spectral resolution. Particular schemes of x-ray echo spectrometers for 0.1-0.02 meV ultrahigh-resolution IXS applications (resolving power >10^{8}) with broadband ≃5-13  meV dispersing systems are introduced featuring more than 10^{3} signal enhancement. The technique is general, applicable in different photon frequency domains.

  12. X-ray diagnostics of massive star winds

    Science.gov (United States)

    Oskinova, Lidia M.

    2016-09-01

    Nearly all types of massive stars with radiatively driven stellar winds are X-ray sources that can be observed by the presently operating powerful X-ray telescopes. In this review I briefly address recent advances in our understanding of stellar winds obtained from X-ray observations. X-rays may strongly influence the dynamics of weak winds of main sequence B-type stars. X-ray pulsations were detected in a β Cep type variable giving evidence of tight photosphere-wind connections. The winds of OB dwarfs with subtypes later than O9V may be predominantly in a hot phase, and X-ray observations offer the best window for their studies. The X-ray properties of OB supergiants are largely determined by the effects of radiative transfer in their clumped stellar winds. The recently suggested method to directly measure mass-loss rates of O stars by fitting the shapes of X-ray emission lines is considered but its validity cannot be confirmed. To obtain robust quantitative information on stellar wind parameters from X-ray spectroscopy, a multiwavelength analysis by means of stellar atmosphere models is required. Independent groups are now performing such analyses with encouraging results. Joint analyses of optical, UV, and X-ray spectra of OB supergiants yield consistent mass-loss rates. Depending on the adopted clumping parameters, the empirically derived mass-loss rates are a factor of a few smaller or comparable to those predicted by standard recipes (Vink et al., 2001). All sufficiently studied O stars display variable X-ray emission that might be related to corotating interaction regions in their winds. In the latest stages of stellar evolution, single red supergiants (RSG) and luminous blue variable (LBV) stars do not emit observable amounts of X-rays. On the other hand, nearly all types of Wolf-Rayet (WR) stars are X-ray sources. X-ray spectroscopy allows a sensitive probe of WR wind abundances and opacities.

  13. Repetition rate continuously tunable 10-GHz picosecond mode-locked fiber ring laser

    Institute of Scientific and Technical Information of China (English)

    Fang Wan; Ziyu Wang

    2006-01-01

    A couple of simple-structure phase modulators were used in active mode-locked fiber laser to implement repetition rate continuous tuning. The laser produces pulse as short as 5.7 ps whose repetition rate tuning can cover the spacing of the adjoining order mode-locking frequencies.

  14. High-repetition-rate XeCl waveguide laser without gas flow

    Energy Technology Data Exchange (ETDEWEB)

    Christensen, C.P.; Gordon C. III; Moutoulas, C.; Feldman, B.J.

    1987-03-01

    Operation of a microwave discharge XeCl laser at pulse-repetition rates extending to 8 kHz without flow of the laser gas is reported. Present limits on pulse-repetition rate appear to be imposed by thermally induced refractive-index gradients.

  15. An Optimization of Super-Miniature X-ray Target

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyun Jin; Heo, Sung Hwan; Ha, Jun Mok; Cho, Sung Oh [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of)

    2011-05-15

    Electronic brachytherapy is now becoming popular because it has certain advantages over the radionuclide based brachytherapy sources. Unlike radionuclide based source, electronic brachytherapy system generates radiation using an X-ray tube. In case of radionuclide-based source, radiation is always produced regardless of needs. But X-ray produced from electronic brachytherapy system can be turned on and off thus we can get only the desired X-ray. Secondly, the dose rate can be easily controlled by adjusting operating voltage and current of electronic brachytherapy system. Lastly, electronic brachytherapy system precludes the hazards of handling the radioactive source. When we use the radiation for brachytherapy or intra-cavity imaging, one of the important concerns is the uniformity of X-ray dose distribution. Dose distribution from electronic brachytherapy system is determined by structure and geometry of X-ray target

  16. X-ray imaging: Perovskites target X-ray detection

    Science.gov (United States)

    Heiss, Wolfgang; Brabec, Christoph

    2016-05-01

    Single crystals of perovskites are currently of interest to help fathom fundamental physical parameters limiting the performance of perovskite-based polycrystalline solar cells. Now, such perovskites offer a technology platform for optoelectronic devices, such as cheap and sensitive X-ray detectors.

  17. Portable X-Ray Device

    Science.gov (United States)

    1983-01-01

    Portable x-ray instrument developed by NASA now being produced commercially as an industrial tool may soon find further utility as a medical system. The instrument is Lixiscope - Low Intensity X-Ray Imaging Scope -- a self-contained, battery-powered fluoroscope that produces an instant image through use of a small amount of radioactive isotope. Originally developed by Goddard Space Flight Center, Lixiscope is now being produced by Lixi, Inc. which has an exclusive NASA license for one version of the device.

  18. Neutron and X-ray Detectors

    Energy Technology Data Exchange (ETDEWEB)

    Carini, Gabriella [SLAC National Accelerator Lab., Menlo Park, CA (United States); Denes, Peter [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Gruener, Sol [Cornell Univ., Ithaca, NY (United States); Lessner, Elianne [Dept. of Energy (DOE), Washington DC (United States). Office of Science Office of Basic Energy Sciences

    2012-08-01

    (and two computing hurdles that result from the corresponding increase in data volume) for the detector community to overcome in order to realize the full potential of BES neutron and X-ray facilities. Resolving these detector impediments will improve scientific productivity both by enabling new types of experiments, which will expand the scientific breadth at the X-ray and neutron facilities, and by potentially reducing the beam time required for a given experiment. These research priorities are summarized in the table below. Note that multiple, simultaneous detector improvements are often required to take full advantage of brighter sources. High-efficiency hard X-ray sensors: The fraction of incident particles that are actually detected defines detector efficiency. Silicon, the most common direct-detection X-ray sensor material, is (for typical sensor thicknesses) 100% efficient at 8 keV, 25%efficient at 20 keV, and only 3% efficient at 50 keV. Other materials are needed for hard X-rays. Replacement for 3He for neutron detectors: 3He has long been the neutron detection medium of choice because of its high cross section over a wide neutron energy range for the reaction 3He + n —> 3H + 1H + 0.764 MeV. 3He stockpiles are rapidly dwindling, and what is available can be had only at prohibitively high prices. Doped scintillators hold promise as ways to capture neutrons and convert them into light, although work is needed on brighter, more efficient scintillator solutions. Neutron detectors also require advances in speed and resolution. Fast-framing X-ray detectors: Today’s brighter X-ray sources make time-resolved studies possible. For example, hybrid X-ray pixel detectors, initially developed for particle physics, are becoming fairly mature X-ray detectors, with considerable development in Europe. To truly enable time-resolved studies, higher frame rates and dynamic range are required, and smaller pixel sizes are desirable. High-speed spectroscopic X-ray detectors

  19. X-ray photoelectron spectroscopy analysis for the chemical impact of solvent addition rate on electromagnetic shielding effectiveness of HCl-doped polyaniline nanopowders

    Energy Technology Data Exchange (ETDEWEB)

    Tantawy, Hesham Ramzy; Aston, D. Eric, E-mail: aston@uidaho.edu [Department of Chemical & Materials Engineering, University of Idaho, 875 Perimeter Dr. MS 1021, Moscow, Idaho 83844-1021 (United States); Kengne, Blaise-Alexis F.; McIlroy, David N.; Qiang, You [Department of Physics, University of Idaho, Moscow, Idaho 83844 (United States); Nguyen, Tai; Heo, Deukhyoun [School of Electrical Engineering and Computer Science, Washington State University, EME 102 Spokane St., Pullman, Washington 99164 (United States)

    2015-11-07

    An in-depth analysis of the chemical functionality in HCl-doped polyaniline (PANI) nanopowders is discussed through interpretations of x-ray photoelectron spectra. The distinctions between three PANI sample types, produced under varied synthesis conditions, are compared on the basis correlations between newly collected electron spectra for chemical analysis (or also x-ray photoelectron spectroscopy) and electromagnetic (EM) shielding effectiveness (SE) within two frequency bands (100–1500 MHz and ∼2–14 GHz). The findings are discussed with reference to previous data analysis of electrical conductivities and Raman and UV-vis spectra analyzed from replicates of the same PANI nanopowders, where only the 8–12 GHz range for SE was tested. They further corroborate previous results for limited-solvent conditions that enhance EM shielding. The three nanopowder types show distinctive differences in polaron, bipolaron, and polar lattice contributions. The collective findings describe the chemical connections between controlling and, most importantly, limiting the available solvent for polymerization with simultaneously doping and how it is that the newly developed solvent-limited approach for HCl-PANI nanopowders provides better shielding than traditionally solvent-rich methods by having more extended and perhaps even faster polaron delocalization than other PANI-based products. The maximum oxidation (50%) and doping (49%) levels obtained in the solvent-free nanopowders also produced the highest SE values of 37.3 ± 3.7 dB (MHz band) and 68.6 ± 4.6 dB (GHz band)

  20. 髋臼隐匿性骨折CT与X线平片检查诊断率对比分析%Comparative Analysis of CT and X-ray Diagnosis Rate of Occult Acetabulum Fracture

    Institute of Scientific and Technical Information of China (English)

    李国良

    2011-01-01

    Objective To investigate the appropriate diagnostic imaging method for evaluating occult acetabulum fracture in order to improve the diagnostic accuracy. Methods Retrospective analysis of 48 patients with occult acetabulum fracture was undertaken by X-ray and CT scans. We evaluated the detection rate of occult acetabulum fracture between CT and X-ray. Results According to Letournel Classification, there were 16 cases of anterior wall, 14 cases of posterior wall, 8 cases of anterior column and 10 cases of posterior column fractures. 28 (58.3% ) patients were suspected as having fracture line on the X -ray film. On the contrary, 48 (100.0% ) patients demonstrated occult acetabulum fracture line on CT. Conclusion CT has higher sensitivity than X-ray in detecting occult acetabulum fracture. Compared with X-ray, CT scanning allows a more precise determination of the degree of occult acetabulum fracture involvement and therefore is helpful in the planning of orthopedic surgery.%目的 探讨髋臼隐匿性骨折适宜的影像学诊断方法,提高其诊断准确性.方法 回顾性分析48例髋臼隐匿性骨折CT与X线平片影像学资料,评价CT与X线平片检查对髋臼隐匿性骨折的诊断率.结果 本组48例按Letournel分类,骨折位于髋臼前壁16例、后壁14例、前柱8例、后柱10例.CT检查诊断髋臼隐匿性骨折48例,诊断率100.0%;X线平片检查疑有髋臼隐匿性骨折28例,诊断率58.3%.结论 CT检查对髋臼隐匿性骨折的诊断率明显高于X线平片检查,X线平片检查可作为髋臼隐匿性骨折的初筛方法,CT检查则可为髋臼隐匿性骨折及其伴随损伤提供更准确的诊断信息.

  1. X-ray transient AGN and galaxies, and why we need new soft X-ray surveys

    CERN Document Server

    Grupe, D

    2002-01-01

    X-ray transience is the most extreme form of variability observed in AGN or normal non-active galaxies. While factors of 2-3 on timescales of days to years are quite common among AGN, X-ray transients appear only once and vanish from the X-ray sky years later. The ROSAT All-Sky Survey with its sensitivity to energies down to 0.1 keV was the an ideal tool to discover these sources. X-ray transience in AGN or galaxies can be caused by dramatic changes in the accretion rate of the central black hole or by changes of the properties of the accretion disk. So far only a handful of sources are known. In order to estimate how often such an event occurs in a galaxy, a new soft X-ray survey is needed. In these proceedings I describe the currently known X-ray transient AGN and galaxies and will argue for a new soft X-ray survey in order to discover more of these extreme X-ray sources.

  2. Safety and efficacy of low fluence, high repetition rate versus high fluence, low repetition rate 810-nm diode laser for axillary hair removal in Chinese women.

    Science.gov (United States)

    Li, Wenhai; Liu, Chengyi; Chen, Zhou; Cai, Lin; Zhou, Cheng; Xu, Qianxi; Li, Houmin; Zhang, Jianzhong

    2016-11-01

    High-fluence diode lasers with contact cooling have emerged as the gold standard to remove unwanted hair. Lowering the energy should result in less pain and could theoretically affect the efficacy of the therapy. To compare the safety and efficacy of a low fluence high repetition rate 810-nm diode laser to those of a high fluence, low repetition rate diode laser for permanent axillary hair removal in Chinese women. Ninety-two Chinese women received four axillae laser hair removal treatments at 4-week intervals using the low fluence, high repetition rate 810-nm diode laser in super hair removal (SHR) mode on one side and the high fluence, low repetition rate diode laser in hair removal (HR) mode on the other side. Hair counts were done at each follow-up visit and 6-month follow-up after the final laser treatment using a "Hi Quality Hair Analysis Program System"; the immediate pain score after each treatment session was recorded by a visual analog scale. The overall median reduction of hair was 90.2% with the 810-nm diode laser in SHR mode and 87% with the same laser in HR mode at 6-month follow-up. The median pain scores in SHR mode and in HR mode were 2.75 and 6.75, respectively. Low fluence, high repetition rate diode laser can efficiently remove unwanted hair but also significantly improve tolerability and reduce adverse events during the course of treatment.

  3. X-ray imaging detectors for synchrotron and XFEL sources

    OpenAIRE

    Takaki Hatsui; Heinz Graafsma

    2015-01-01

    Current trends for X-ray imaging detectors based on hybrid and monolithic detector technologies are reviewed. Hybrid detectors with photon-counting pixels have proven to be very powerful tools at synchrotrons. Recent developments continue to improve their performance, especially for higher spatial resolution at higher count rates with higher frame rates. Recent developments for X-ray free-electron laser (XFEL) experiments provide high-frame-rate integrating detectors with both high sensitivit...

  4. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... small burst of radiation that passes through the body, recording an image on photographic film or a special detector. Different ... This ensures that those parts of a patient's body not being imaged receive minimal radiation ... x-ray images are among the clearest, most detailed views of ...

  5. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... for more information about pregnancy and x-rays. A Word About Minimizing Radiation Exposure Special care is ... encourage linking to this site. × Recommend RadiologyInfo to a friend Send to (friend's e-mail address): From ( ...

  6. X-rays and magnetism.

    Science.gov (United States)

    Fischer, Peter; Ohldag, Hendrik

    2015-09-01

    Magnetism is among the most active and attractive areas in modern solid state physics because of intriguing phenomena interesting to fundamental research and a manifold of technological applications. State-of-the-art synthesis of advanced magnetic materials, e.g. in hybrid structures paves the way to new functionalities. To characterize modern magnetic materials and the associated magnetic phenomena, polarized x-rays have emerged as unique probes due to their specific interaction with magnetic materials. A large variety of spectroscopic and microscopic techniques have been developed to quantify in an element, valence and site-sensitive way properties of ferro-, ferri-, and antiferromagnetic systems, such as spin and orbital moments, and to image nanoscale spin textures and their dynamics with sub-ns time and almost 10 nm spatial resolution. The enormous intensity of x-rays and their degree of coherence at next generation x-ray facilities will open the fsec time window to magnetic studies addressing fundamental time scales in magnetism with nanometer spatial resolution. This review will give an introduction into contemporary topics of nanoscale magnetic materials and provide an overview of analytical spectroscopy and microscopy tools based on x-ray dichroism effects. Selected examples of current research will demonstrate the potential and future directions of these techniques.

  7. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... Español More Info Images/Videos About Us News Physician Resources Professions Site Index A-Z X-ray ( ... are the fastest and easiest way for your doctor to view and assess bone fractures, injuries and ...

  8. X-Ray Diffractive Optics

    Science.gov (United States)

    Dennis, Brian; Li, Mary; Skinner, Gerald

    2013-01-01

    X-ray optics were fabricated with the capability of imaging solar x-ray sources with better than 0.1 arcsecond angular resolution, over an order of magnitude finer than is currently possible. Such images would provide a new window into the little-understood energy release and particle acceleration regions in solar flares. They constitute one of the most promising ways to probe these regions in the solar atmosphere with the sensitivity and angular resolution needed to better understand the physical processes involved. A circular slit structure with widths as fine as 0.85 micron etched in a silicon wafer 8 microns thick forms a phase zone plate version of a Fresnel lens capable of focusing approx. =.6 keV x-rays. The focal length of the 3-cm diameter lenses is 100 microns, and the angular resolution capability is better than 0.1 arcsecond. Such phase zone plates were fabricated in Goddard fs Detector Development Lab. (DDL) and tested at the Goddard 600-microns x-ray test facility. The test data verified that the desired angular resolution and throughput efficiency were achieved.

  9. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... and places the x-ray film holder or digital recording plate under the table in the area of the body being imaged. When necessary, sandbags, pillows or other positioning devices will be used to help you maintain the ...

  10. Alpha proton x ray spectrometer

    Science.gov (United States)

    Rieder, Rudi; Waeke, H.; Economou, T.

    1994-01-01

    Mars Pathfinder will carry an alpha-proton x ray spectrometer (APX) for the determination of the elemental chemical composition of Martian rocks and soils. The instrument will measure the concentration of all major and some minor elements, including C, N, and O at levels above typically 1 percent.

  11. X-ray backscatter imaging

    Science.gov (United States)

    Dinca, Dan-Cristian; Schubert, Jeffrey R.; Callerame, J.

    2008-04-01

    In contrast to transmission X-ray imaging systems where inspected objects must pass between source and detector, Compton backscatter imaging allows both the illuminating source as well as the X-ray detector to be on the same side of the target object, enabling the inspection to occur rapidly and in a wide variety of space-constrained situations. A Compton backscatter image is similar to a photograph of the contents of a closed container, taken through the container walls, and highlights low atomic number materials such as explosives, drugs, and alcohol, which appear as especially bright objects by virtue of their scattering characteristics. Techniques for producing X-ray images based on Compton scattering will be discussed, along with examples of how these systems are used for both novel security applications and for the detection of contraband materials at ports and borders. Differences between transmission and backscatter images will also be highlighted. In addition, tradeoffs between Compton backscatter image quality and scan speed, effective penetration, and X-ray source specifications will be discussed.

  12. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available Toggle navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos About Us News Physician ... An x-ray (radiograph) is a noninvasive medical test that helps physicians diagnose and treat medical conditions. ...

  13. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... for more information about pregnancy and x-rays. A Word About Minimizing Radiation Exposure Special care is ... encourage linking to this site. × Recommend RadiologyInfo to a friend Send to (friend's e-mail address): From ( ...

  14. Stellar X-Ray Polarimetry

    Science.gov (United States)

    Swank, J.

    2011-01-01

    Most of the stellar end-state black holes, pulsars, and white dwarfs that are X-ray sources should have polarized X-ray fluxes. The degree will depend on the relative contributions of the unresolved structures. Fluxes from accretion disks and accretion disk corona may be polarized by scattering. Beams and jets may have contributions of polarized emission in strong magnetic fields. The Gravity and Extreme Magnetism Small Explorer (GEMS) will study the effects on polarization of strong gravity of black holes and strong magnetism of neutron stars. Some part of the flux from compact stars accreting from companion stars has been reflected from the companion, its wind, or accretion streams. Polarization of this component is a potential tool for studying the structure of the gas in these binary systems. Polarization due to scattering can also be present in X-ray emission from white dwarf binaries and binary normal stars such as RS CVn stars and colliding wind sources like Eta Car. Normal late type stars may have polarized flux from coronal flares. But X-ray polarization sensitivity is not at the level needed for single early type stars.

  15. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... dislocations. In elderly or patients with osteoporosis, a hip fracture may be clearly seen on a CT scan, while it may be barely seen, if at all, on a hip x-ray. For suspected spine injury or other ...

  16. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available Toggle navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos About Us News Physician ... An x-ray (radiograph) is a noninvasive medical test that helps physicians diagnose and treat medical conditions. ...

  17. High-Resolution X-ray Emission and X-ray Absorption Spectroscopy

    OpenAIRE

    de Groot, F. M. F.

    2001-01-01

    In this review, high-resolution X-ray emission and X-ray absorption spectroscopy will be discussed. The focus is on the 3d transition-metal systems. To understand high-resolution X-ray emission and reso-nant X-ray emission, it is first necessary to spend some time discussing the X-ray absorption process. Section II discusses 1s X-ray absorption, i.e., the K edges, and section III deals with 2p X-ray absorption, the L edges. X-ray emission is discussed in, respectively, the L edges. X-ray emis...

  18. Can a variable alpha induce limit cycle behavior and exponential luminosity decay in transient soft x ray sources?

    Science.gov (United States)

    Meirellesfilho, C.; Liang, Edison P.

    1994-01-01

    There has been, recently, a revival of the stability problem of accretion disks. Much of this renewed interest is due to recent observational data on transient soft X-ray novae, which are low-mass X-ray binaries. It is widely believed that nonsteady mass transfer from the secondary onto the compact primary, through an accretion disk, is the reason for the observed spectacular events in the form of often repetitive outbursts, with recurrence times ranging from 1 to 60 yr and duration time on the scale of months. Though not having reached yet a consensus about the nature of the mechanism that regulates the mass transfer, the disk thermal instability model seems to be favored by the fact that the rise in the hard X-ray luminosity is prior to the rise in the soft X-ray luminosity, while the mass transfer instability model seems to be hindered by the fact that the luminosity during quiescence is unable to trigger the thermal instability. However, it should be stressed that, remarkably, the X-ray light curves of these X-ray novae all show overall exponential decays, a feature quite difficult to reproduce in the framework of the viscous disk model, which yields powerlike luminosity decay. Taking into account this observational constraint, we have studied the temporal evolution of perturbations in the accretion rate, under the assumption that alpha is radial and parameter dependent. The chosen dependence is such that the model can reproduce limit cycle behavior (the system is locally unstable but globally stable). However, the kind of dependence we are looking for in alpha does not allow us to use the usual Shakura and Sunyaev procedure in the sense that we no longer can obtain a linearized continuity equation without explicit dependence on the accretion rate. This is so because now we cannot eliminate the accretion rate by using the angular momentum conservation equation.

  19. High-Resolution X-ray Emission and X-ray Absorption Spectroscopy

    NARCIS (Netherlands)

    Groot, F.M.F. de

    2000-01-01

    In this review, high-resolution X-ray emission and X-ray absorption spectroscopy will be discussed. The focus is on the 3d transition-metal systems. To understand high-resolution X-ray emission and reso-nant X-ray emission, it is first necessary to spend some time discussing the X-ray absorption

  20. Femtosecond and picosecond laser drilling of metals at high repetition rates and average powers.

    Science.gov (United States)

    Ancona, A; Döring, S; Jauregui, C; Röser, F; Limpert, J; Nolte, S; Tünnermann, A

    2009-11-01

    The influence of pulse duration on the laser drilling of metals at repetition rates of up to 1 MHz and average powers of up to 70 W has been experimentally investigated using an ytterbium-doped-fiber chirped-pulse amplification system with pulses from 800 fs to 19 ps. At a few hundred kilohertz particle shielding causes an increase in the number of pulses for breakthrough, depending on the pulse energy and duration. At higher repetition rates, the heat accumulation effect overbalances particle shielding, but significant melt ejection affects the hole quality. Using femtosecond pulses, heat accumulation starts at higher repetition rates, and the ablation efficiency is higher compared with picosecond pulses.

  1. Pulsed pumped Yb-doped fiber amplifier at low repetition rate

    Institute of Scientific and Technical Information of China (English)

    Changgeng Ye; Ping Yan; Mali Gong; Ming Lei

    2005-01-01

    A pulsed pumped Yb-doped double-clad fiber (DCF) master-oscillator power amplifier (MOPA) at low repetition rate is reported. Seeded by a passive Q-switched Nd:YAG microchip laser, the fiber amplifier can generate 167-kW peak-power and 0.83-ns duration pulses at 200-Hz repetition rate. Because of the pulsed pump approach, the amplified spontaneous emission (ASE) and the spurious lasing between pulses are well avoided, and the repetition rate can be set freely from single-shot to 1 kHz. Peak power scaling limitations that arise from the fiber facet damage are discussed.

  2. Developing small vacuum spark as an x-ray source for calibration of an x-ray focusing crystal spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Ghomeishi, Mostafa; Adikan, Faisal Rafiq Mahamd [Photonic Research Group, Department of Electrical Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur (Malaysia); Karami, Mohammad [Department of Mechanical Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur (Malaysia)

    2012-10-15

    A new technique of x-ray focusing crystal spectrometers' calibration is the desired result. For this purpose the spectrometer is designed to register radiated copper K{alpha} and K{beta} lines by using a flat {alpha}-quartz crystal. This experiment uses pre-breakdown x-ray emissions in low vacuum of about 2.5-3 mbar. At this pressure the pinch will not form so the plasma will not radiate. The anode material is copper and the capacity of the capacitor bank is 22.6 nF. This experiment designed and mounted a repetitive triggering system to save the operator time making hundreds of shots. This emission amount is good for calibration and geometrical adjustment of an optical crystal x-ray focusing spectrometer.

  3. Developing small vacuum spark as an x-ray source for calibration of an x-ray focusing crystal spectrometer.

    Science.gov (United States)

    Ghomeishi, Mostafa; Karami, Mohammad; Adikan, Faisal Rafiq Mahamd

    2012-10-01

    A new technique of x-ray focusing crystal spectrometers' calibration is the desired result. For this purpose the spectrometer is designed to register radiated copper Kα and Kβ lines by using a flat α-quartz crystal. This experiment uses pre-breakdown x-ray emissions in low vacuum of about 2.5-3 mbar. At this pressure the pinch will not form so the plasma will not radiate. The anode material is copper and the capacity of the capacitor bank is 22.6 nF. This experiment designed and mounted a repetitive triggering system to save the operator time making hundreds of shots. This emission amount is good for calibration and geometrical adjustment of an optical crystal x-ray focusing spectrometer.

  4. X-ray reprocessing in binaries

    Science.gov (United States)

    Paul, Biswajit

    2016-07-01

    We will discuss several aspects of X-ray reprocessing into X-rays or longer wavelength radiation in different kinds of binary systems. In high mass X-ray binaries, reprocessing of hard X-rays into emission lines or lower temperature black body emission is a useful tool to investigate the reprocessing media like the stellar wind, clumpy structures in the wind, accretion disk or accretion stream. In low mass X-ray binaries, reprocessing from the surface of the companion star, the accretion disk, warps and other structures in the accretion disk produce signatures in longer wavelength radiation. X-ray sources with temporal structures like the X-ray pulsars and thermonuclear burst sources are key in such studies. We will discuss results from several new investigations of X-ray reprocessing phenomena in X-ray binaries.

  5. Silicon avalanche photodiodes for direct detection of X-rays.

    Science.gov (United States)

    Baron, Alfred Q R; Kishimoto, Shunji; Morse, John; Rigal, Jean Marie

    2006-03-01

    Silicon avalanche photodiodes (APDs) are discussed as fast X-ray detectors for synchrotron radiation. The emphasis is on ;direct' detection, where the X-ray is absorbed within the silicon APD itself, and, therefore, on use with medium-energy X-rays, <30 keV. The impact of APD structure on device performance is examined, and representative data from many different commercial devices are presented. Specific areas discussed include signal shapes, high-rate behavior, time resolution and pulse-height response. Data from several APD arrays are also presented, as is a detailed description of an integrated package system. Tables are included comparing commercially available devices, including arrays.

  6. X-ray imaging detectors for synchrotron and XFEL sources

    Directory of Open Access Journals (Sweden)

    Takaki Hatsui

    2015-05-01

    Full Text Available Current trends for X-ray imaging detectors based on hybrid and monolithic detector technologies are reviewed. Hybrid detectors with photon-counting pixels have proven to be very powerful tools at synchrotrons. Recent developments continue to improve their performance, especially for higher spatial resolution at higher count rates with higher frame rates. Recent developments for X-ray free-electron laser (XFEL experiments provide high-frame-rate integrating detectors with both high sensitivity and high peak signal. Similar performance improvements are sought in monolithic detectors. The monolithic approach also offers a lower noise floor, which is required for the detection of soft X-ray photons. The link between technology development and detector performance is described briefly in the context of potential future capabilities for X-ray imaging detectors.

  7. X-ray imaging detectors for synchrotron and XFEL sources.

    Science.gov (United States)

    Hatsui, Takaki; Graafsma, Heinz

    2015-05-01

    Current trends for X-ray imaging detectors based on hybrid and monolithic detector technologies are reviewed. Hybrid detectors with photon-counting pixels have proven to be very powerful tools at synchrotrons. Recent developments continue to improve their performance, especially for higher spatial resolution at higher count rates with higher frame rates. Recent developments for X-ray free-electron laser (XFEL) experiments provide high-frame-rate integrating detectors with both high sensitivity and high peak signal. Similar performance improvements are sought in monolithic detectors. The monolithic approach also offers a lower noise floor, which is required for the detection of soft X-ray photons. The link between technology development and detector performance is described briefly in the context of potential future capabilities for X-ray imaging detectors.

  8. X-ray outbursts of low-mass X-ray binary transients observed in the RXTE era

    CERN Document Server

    Yan, Zhen

    2014-01-01

    We have performed a statistical study of the outburst properties of 110 bright X-ray outbursts in 36 low-mass X-ray binary transients (LMXBTs) seen with the All-Sky Monitor (ASM; 2--12 keV) on board the Rossi X-ray Timing Explorer ({\\it RXTE}) in 1996--2011. We have measured a number of outburst properties including peak X-ray luminosity, rate-of-change of luminosity on daily timescale, $e$-folding rise and decay timescales, outburst duration and total radiated energy. We found the average values of some properties such as peak X-ray luminosity, rise and decay timescales, outburst duration and total radiated energy of black hole LMXBTs are at least two times larger than those of neutron star LMXBTs, implying that these properties can be used to infer the nature of the central compact object of a newly discovered LMXBT. We also found the outburst peak X-ray luminosity is correlated with the rate-of-change of X-ray luminosity in both the rise and the decay phases, which is consistent with our previous studies. ...

  9. Jupiter's X-ray aurora via polar ion precipitation

    Science.gov (United States)

    Young, Jackson; Houston, Stephen

    2017-01-01

    Jupiter's auroral X-ray emission was first observed by the Einstein X-ray Observatory in 1979 and has since been observed over the past 20 years by the Roentgen satellite, Chandra X-ray Observatory, and XMM-Newton. The strong X-ray emission produces a spectacular 1 GW of total power at the polar caps. There has been extensive research of X-ray production from incident electrons; however, this has not been able to account for the full power of the generated X-rays. The remainder of the X-ray production can be modeled and reproduced into observable results by the precipitation of several MeV oxygen and sulfur ions from the outer magnetosphere into an atmosphere that has been adapted to the auroral conditions. The present research uses a revised model of a hybrid Monte Carlo method with varying oxygen ion energies (10 keV/u - 5 MeV/u) and updated collision cross-sections to concentrate on the ionization of the atmosphere, generation of secondary electron fluxes and their escape from the atmosphere, and characterization of the H2 Lyman-Werner band emission. Predictions relevant to awaited NASA's Juno results are made: escaping electrons with an energy range of 1 eV to 6 keV, H2 band emission rates of 80 kR, and downward field-aligned currents of at least 2 MA.

  10. A compliance testing program for diagnostic X-ray equipment

    Energy Technology Data Exchange (ETDEWEB)

    Hutchinson, D.E.; Cobb, B.J.; Jacob, C.S

    1999-01-01

    Compliance testing is nominally that part of a quality assurance program dealing with those aspects of X-ray equipment performance that are subject to radiation control legislation. Quality assurance programs for medical X-ray equipment should be an integral part of the quality culture in health care. However while major hospitals and individual medical centers may implement such programs with some diligence, much X-ray equipment can remain unappraised unless there is a comprehensive regulatory inspection program or some form of compulsion on the equipment owner to implement a testing program. Since the late 1950s all X-ray equipment in the State of Western Australia has been inspected by authorized officers acting on behalf of the Radiological Council, the regulatory authority responsible for administration of the State's Radiation Safety Act. However, economic constraints, coupled with increasing X-ray equipment numbers and a geographically large State have significantly affected the inspection rate. Data available from inspections demonstrate that regular compliance and performance checks are essential in order to ensure proper performance and to minimize unnecessary patient and operator dose. To ensure that diagnostic X-ray equipment complies with accepted standards and performance criteria, the regulatory authority introduced a compulsory compliance testing program for all medical, dental and chiropractic diagnostic X-ray equipment effective from 1 January 1997.

  11. X-ray diagnostics of massive star winds

    CERN Document Server

    Oskinova, Lidia

    2016-01-01

    Nearly all types of massive stars with radiatively driven stellar winds are X-ray sources that can be observed by the presently operating powerful X-ray telescopes. In this review I briefly address recent advances in our understanding of stellar winds obtained from X-ray observations. The winds of OB dwarfs with subtypes later than O9V may be predominantly in a hot phase, and X-ray observations offer the best window for their studies. The X-ray properties of OB supergiants are largely determined by the effects of radiative transfer in their clumped stellar winds. The recently suggested method to directly measure mass-loss rates of O stars by fitting the shapes of X-ray emission lines is considered but its validity cannot be confirmed. To obtain robust quantitative information on stellar wind parameters from X-ray spectroscopy, a multiwavelength analysis by means of stellar atmosphere models is required. Independent groups are now performing such analyses with encouraging results. Joint analyses of optical, UV...

  12. Design Studies for a VUV--Soft X-ray Free-Electron Laser Array

    Energy Technology Data Exchange (ETDEWEB)

    Corlett, J.; Baptiste, K.; Byrd, J.M.; Denes, P.; Falcone, R.; Kirz, J.; McCurdy, W.; Padmore, H.; Penn, G.; Qiang, J.; Robin, D.; Sannibale, F.; Schoenlein, R.; Staples, J.; Steier, C.; Venturnini, M.; Wan, W.; Wells, R.; Wilcox, R.; Zholents, A.

    2009-08-04

    Several recent reports have identified the scientific requirements for a future soft X-ray light source [1, 2, 3, 4, 5], and a high-repetition-rate free-electron laser (FEL) facility responsive to them is being studied at Lawrence Berkeley National Laboratory (LBNL) [6]. The facility is based on a continuous-wave (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 the experimental requirements, the individualFELs may be configured for either self-amplified spontaneous emission (SASE), seeded highgain harmonic generation (HGHG), echo-enabled harmonic generation (EEHG), or oscillator mode of operation, and will produce high peak and average brightness x-rays with a flexible pulse format ranging from sub-femtoseconds to hundreds of femtoseconds. This new light source would serve a broad community of scientists in many areas of research, similar to existing utilization of storage ring based light sources. To reduce technical risks and constructioncosts, accelerator research, development, and design studies at LBNL target the most critical components and systems of the facility. We are developing a high-repetition-rate low-emittance electron gun, high quantum efficiency photocathodes, and have embarked on design and optimization of the electron beam accelerator, FEL switchyard, and array of FELs. We continue our work on precision timing and synchronization systems critical for time-resolved experiments using pump-probe techniques.

  13. Hydrodynamic size distribution of gold nanoparticles controlled by repetition rate during pulsed laser ablation in water

    Science.gov (United States)

    Menéndez-Manjón, Ana; Barcikowski, Stephan

    2011-02-01

    Most investigations on the laser generation and fragmentation of nanoparticles focus on Feret particle size, although the hydrodynamic size of nanoparticles is of great importance, for example in biotechnology for diffusion in living cells, or in engineering, for a tuned rheology of suspensions. In this sense, the formation and fragmentation of gold colloidal nanoparticles using femtosecond laser ablation at variable pulse repetition rates (100-5000 Hz) in deionized water were investigated through their plasmon resonance and hydrodynamic diameter, measured by Dynamic Light Scattering. The increment of the repetition rate does not influence the ablation efficiency, but produces a decrease of the hydrodynamic diameter and blue-shift of the plasmon resonance of the generated gold nanoparticles. Fragmentation, induced by inter-pulse irradiation of the colloids was measured online, showing to be more effective low repetition rates. The pulse repetition rate is shown to be an appropriate laser parameter for hydrodynamic size control of nanoparticles without further influence on the production efficiency.

  14. High Energy Single Frequency Fiber Laser at Low Repetition Rate Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This SBIR phase II project proposes a single frequency high energy fiber laser system operating at low repetition rate of 10 Hz to 1 kHz for coherent Lidar systems...

  15. Repetition rate tunable ultra-short optical pulse generation based on electrical pattern generator

    Institute of Scientific and Technical Information of China (English)

    Xin Fu; Hongming Zhang; Meng Yan; Minyu Yao

    2009-01-01

    @@ An actively mode-locked laser with tunable repetition rate is proposed and experimentally demonstrated based on a programmable electrical pattern generator.By changing the repetition rate of the electrical patterns applied on the in-cavity modulator, the repetition rate of the output optical pulse sequences changes accordingly while the pulse width of the optical pulse train remains almost constant.In other words, the output ultra-short pulse train has a tunable duty cycle.In a proof-of-principle experiment, optical pulses with repetition rates of 10, 5, 2.5 and 1.25 GHz are obtained by adjusting the electrical pattern applied on the in-cavity modulator while their pulse widths remain almost unchanged.

  16. X-Ray-powered Macronovae

    Science.gov (United States)

    Kisaka, Shota; Ioka, Kunihito; Nakar, Ehud

    2016-02-01

    A macronova (or kilonova) was observed as an infrared excess several days after the short gamma-ray burst GRB 130603B. Although the r-process radioactivity is widely discussed as an energy source, it requires a huge mass of ejecta from a neutron star (NS) binary merger. We propose a new model in which the X-ray excess gives rise to the simultaneously observed infrared excess via thermal re-emission, and explore what constraints this would place on the mass and velocity of the ejecta. This X-ray-powered model explains both the X-ray and infrared excesses with a single energy source such as the central engine like a black hole, and allows for a broader parameter region than the previous models, in particular a smaller ejecta mass ˜ {10}-3{--}{10}-2{M}⊙ and higher iron abundance mixed as suggested by general relativistic simulations for typical NS-NS mergers. We also discuss the other macronova candidates in GRB 060614 and GRB 080503, and the implications for the search of electromagnetic counterparts to gravitational waves.

  17. X-Ray Crystallography Reagent

    Science.gov (United States)

    Morrison, Dennis R. (Inventor); Mosier, Benjamin (Inventor)

    2003-01-01

    Microcapsules prepared by encapsulating an aqueous solution of a protein, drug or other bioactive substance inside a semi-permeable membrane by are disclosed. The microcapsules are formed by interfacial coacervation under conditions where the shear forces are limited to 0-100 dynes per square centimeter at the interface. By placing the microcapsules in a high osmotic dewatering solution. the protein solution is gradually made saturated and then supersaturated. and the controlled nucleation and crystallization of the protein is achieved. The crystal-filled microcapsules prepared by this method can be conveniently harvested and stored while keeping the encapsulated crystals in essentially pristine condition due to the rugged. protective membrane. Because the membrane components themselves are x-ray transparent, large crystal-containing microcapsules can be individually selected, mounted in x-ray capillary tubes and subjected to high energy x-ray diffraction studies to determine the 3-D smucture of the protein molecules. Certain embodiments of the microcapsules of the invention have composite polymeric outer membranes which are somewhat elastic, water insoluble, permeable only to water, salts, and low molecular weight molecules and are structurally stable in fluid shear forces typically encountered in the human vascular system.

  18. Femtosecond Ti:sapphire cryogenic amplifier with high gain and MHz repetition rate.

    Science.gov (United States)

    Dantan, Aurélien; Laurat, Julien; Ourjoumtsev, Alexei; Tualle-Brouri, Rosa; Grangier, Philippe

    2007-07-09

    We demonstrate high gain amplification of 160-femtosecond pulses in a compact double-pass cryogenic Ti:sapphire amplifier. The setup involves a negative GVD mirrors recompression stage, and operates with a repetition rate between 0.2 and 4 MHz with a continuous pump laser. Amplification factors as high as 17 and 320 nJ Fourier-limited pulses are obtained at a 800 kHz repetition rate.

  19. High repetition rate femtosecond dye amplifier using a laser diode pumped neodymium:YAG laser

    Energy Technology Data Exchange (ETDEWEB)

    Zysset, B.; LaGasse, M.J.; Fujimoto, J.G.; Kafka, J.D.

    1989-02-06

    A high repetition rate femtosecond dye amplifier is demonstrated using a laser diode pumped Q-switched Nd:YAG laser. Amplification of wavelength tunable 300 fs pulses from a synchronously mode-locked rhodamine dye laser is achieved with a saturated gain of 70 and a small gain of 200 at a repetition rate of 800 Hz. Maximum pulse energies of 40 nJ are obtained, and pulse compression to as short as 30 fs is demonstrated.

  20. High repetition rate femtosecond dye amplifier using a laser diode pumped neodymium:YAG laser

    Science.gov (United States)

    Zysset, B.; LaGasse, M. J.; Fujimoto, J. G.; Kafka, J. D.

    1989-02-01

    A high repetition rate femtosecond dye amplifier is demonstrated using a laser diode pumped Q-switched Nd:YAG laser. Amplification of wavelength tunable 300 fs pulses from a synchronously mode-locked rhodamine dye laser is achieved with a saturated gain of 70 and a small gain of 200 at a repetition rate of 800 Hz. Maximum pulse energies of 40 nJ are obtained, and pulse compression to as short as 30 fs is demonstrated.

  1. Coupling coefficient for TEA CO2 laser propulsion with variable pulse repetition rate

    Institute of Scientific and Technical Information of China (English)

    Yijun Zheng; Rongqing Tan; Donglei Wang; Guang Zheng; Changjun Ke; Kuohai Zhang; Chongyi Wan; Jin Wu

    2006-01-01

    @@ Because pulse repetition rate affected directly the momentum coupling coefficient of transversely excited atmospheric (TEA) CO2 laser propulsion, a double pulse trigger, controlling high voltage switch of laser excitation circuit, was designed. The pulse interval ranged between 5 and 100 ms. The momentum coupling coefficient for air-breathing mode laser propulsion was studied experimentally. It was found that the momentum coupling coefficient decreased with the pulse repetition rate increasing.

  2. Synchrotron-Radiation Induced X-Ray Emission (SRIXE)

    Energy Technology Data Exchange (ETDEWEB)

    Jones, Keith W.

    1999-09-01

    Elemental analysis using emission of characteristic x rays is a well-established scientific method. The success of this analytical method is highly dependent on the properties of the source used to produce the x rays. X-ray tubes have long existed as a principal excitation source, but electron and proton beams have also been employed extensively. The development of the synchrotron radiation x-ray source that has taken place during the past 40 years has had a major impact on the general field of x-ray analysis. Even tier 40 years, science of x-ray analysis with synchrotron x-ray beams is by no means mature. Improvements being made to existing synchrotron facilities and the design and construction of new facilities promise to accelerate the development of the general scientific use of synchrotron x-ray sources for at least the next ten years. The effective use of the synchrotron source technology depends heavily on the use of high-performance computers for analysis and theoretical interpretation of the experimental data. Fortunately, computer technology has advanced at least as rapidly as the x-ray technology during the past 40 years and should continue to do so during the next decade. The combination of these technologies should bring about dramatic advances in many fields where synchrotron x-ray science is applied. It is interesting also to compare the growth and rate of acceptance of this particular research endeavor to the rates for other technological endeavors. Griibler [1997] cataloged the time required for introduction, diffusion,and acceptance of technological, economic, and social change and found mean values of 40 to 50 years. The introduction of the synchrotron source depends on both technical and non-technical factors, and the time scale at which this seems to be occurring is quite compatible with what is seen for other major innovations such as the railroad or the telegraph. It will be interesting to see how long the present rate of technological change

  3. Fast plasma discharge capillary design as a high power throughput soft x-ray emission source.

    Science.gov (United States)

    Wyndham, E S; Favre, M; Valdivia, M P; Valenzuela, J C; Chuaqui, H; Bhuyan, H

    2010-09-01

    We present the experimental details and results from a low energy but high repetition rate compact plasma capillary source for extreme ultraviolet and soft x-ray research and applications. Two lengths of capillary are mounted in two versions of a closely related design. The discharge operates in 1.6 and 3.2 mm inner diameter alumina capillaries of lengths 21 and 36 mm. The use of water both as dielectric and as coolant simplifies the compact low inductance design with nanosecond discharge periods. The stored electrical energy of the discharge is approximately 0.5 J and is provided by directly charging the capacitor plates from an inexpensive insulated-gate bipolar transistor in 1 μs or less. We present characteristic argon spectra from plasma between 30 and 300 Å as well as temporally resolved x-ray energy fluence in discrete bands on axis. The spectra also allow the level of ablated wall material to be gauged and associated with useful capillary lifetime according to the chosen configuration and energy storage. The connection between the electron beams associated with the transient hollow cathode mechanism, soft x-ray output, capillary geometry, and capillary lifetime is reported. The role of these e-beams and the plasma as measured on-axis is discussed. The relation of the electron temperature and the ionization stages observed is discussed in the context of some model results of ionization in a non-Maxwellian plasma.

  4. Structural biology at the European X-ray free-electron laser facility.

    Science.gov (United States)

    Altarelli, Massimo; Mancuso, Adrian P

    2014-07-17

    The European X-ray free-electron laser (XFEL) facility, under construction in the Hamburg region, will provide high-peak brilliance (greater than 10(33) photons s(-1) mm(-2) mrad(-2) per 0.1% BW), ultrashort pulses (approx. 10 fs) of X-rays, with a high repetition rate (up to 27 000 pulses s(-1)) from 2016 onwards. The main features of this exceptional X-ray source, and the instrumentation developments necessary to exploit them fully, for application to a variety of scientific disciplines, are briefly summarized. In the case of structural biology, that has a central role in the scientific case of this new facility, the instruments and ancillary laboratories that are being planned and built within the baseline programme of the European XFEL and by consortia of users are also discussed. It is expected that the unique features of the source and the advanced features of the instrumentation will allow operation modes with more efficient use of sample materials, faster acquisition times, and conditions better approaching feasibility of single molecule imaging.

  5. Chest X-Ray (Chest Radiography)

    Science.gov (United States)

    ... clothing that might interfere with the x-ray images. Women should always inform their physician and x-ray ... small burst of radiation that passes through the body, recording an image on photographic film or a special detector. Different ...

  6. Testing for X-Ray-SZ Differences and Redshift Evolution in the X-Ray Morphology of Galaxy Clusters

    Science.gov (United States)

    Nurgaliev, D.; McDonald, M.; Benson, B. A.; Bleem, L.; Bocquet, S.; Forman, W. R.; Garmire, G. P.; Gupta, N.; Hlavacek-Larrondo, J.; Mohr, J. J.; Nagai, D.; Rapetti, D.; Stark, A. A.; Stubbs, C. W.; Vikhlinin, A.

    2017-05-01

    We present a quantitative study of the X-ray morphology of galaxy clusters, as a function of their detection method and redshift. We analyze two separate samples of galaxy clusters: a sample of 36 clusters at 0.35clusters at 0.25Clusters from both samples have similar-quality Chandra observations, which allow us to quantify their X-ray morphologies via two distinct methods: centroid shifts (w) and photon asymmetry ({A}{phot}). The latter technique provides nearly unbiased morphology estimates for clusters spanning a broad range of redshift and data quality. We further compare the X-ray morphologies of X-ray- and SZ-selected clusters with those of simulated clusters. We do not find a statistically significant difference in the measured X-ray morphology of X-ray and SZ-selected clusters over the redshift range probed by these samples, suggesting that the two are probing similar populations of clusters. We find that the X-ray morphologies of simulated clusters are statistically indistinguishable from those of X-ray- or SZ-selected clusters, implying that the most important physics for dictating the large-scale gas morphology (outside of the core) is well-approximated in these simulations. Finally, we find no statistically significant redshift evolution in the X-ray morphology (both for observed and simulated clusters), over the range of z˜ 0.3 to z˜ 1, seemingly in contradiction with the redshift-dependent halo merger rate predicted by simulations.

  7. LUX - a recirculating linac-based facility for ultrafast X-ray science

    Energy Technology Data Exchange (ETDEWEB)

    Corlett, J.N.; Barletta, W.A.; DeSantis, S.; Doolittle, L.; Fawley, W.M.; Heimann, P.; Leone, S.; Lidia, S.; Li, D.; Penn, G.; Ratti, A.; Reinsch, M.; Schoenlein, R.; Staples, J.; Stover, G.; Virostek, S.; Wan, W.; Wells, R.; Wilcox, R.; Wolski, A.; Wurtele, J.; Zholents, A.

    2004-06-29

    We present recent developments in design concepts for LUX - a source of ultra-short synchrotron radiation pulses based on a recirculating superconducting linac. The source produces high-flux x-ray pulses with duration of 100 fs or less at a 10 kHz repetition rate, optimized for the study of ultra-fast dynamics across many fields of science [1]. Cascaded harmonic generation in free-electron lasers (FEL's) produces coherent radiation in the VUV-soft x-ray regime, and a specialized technique is used to compress spontaneous emission for ultra-short-pulse photon production in the 1-10 keV range. High-brightness electron bunches of 2-3 mm-mrad emittance at 1 nC charge in 30 ps duration are produced in an rf photocathode gun and compressed to 3 ps duration following an injector linac, and recirculated three times through a 1 GeV main linac. In each return path, independently tunable harmonic cascades are inserted to produce seeded FEL radiation in selected photon energy ranges from approximately 20 eV with a single stage of harmonic generation, to 1 keV with a four-stage cascade. The lattice is designed to minimize emittance growth from effects such as coherent synchrotron radiation (CSR), and resistive wall wakefields. Timing jitter between pump lasers and x-ray pulses is minimized by use of a stable optical master oscillator, distributing timing signals over actively stabilized fiber-optic, phase-locking all lasers to the master oscillator, and generating all rf signals from the master oscillator. We describe technical developments including techniques for minimizing power dissipation in a high repetition rate rf photocathode gun, beam dynamics in two injector configurations, independently tunable beamlines for VUV and soft x-ray production by cascaded harmonic generation, a fast kicker design, timing systems for providing synchronization between experimental pump lasers and the x-ray pulse, and beamline design for maintaining nm-scale density modulation.

  8. X-ray and electron generation in the relativistic lambda-cubed regime

    Science.gov (United States)

    Mordovanakis, Aghapi G.

    Over the last two decades, laser-plasma interactions at relativistic intensities have been carried out using large laser facilities producing at least several hundred millijoule pulses at a repetition rate of 10 Hz or lower. A less explored regime is when intensities in excess of 1018 W/cm2 are attained by focusing millijoule-level femtosecond pulses to a spot with a diameter comparable to the laser wavelength. This so-called relativistic lambda3 regime allows the study of certain laser-plasma experiments at kilohertz repetition rate. The present dissertation contributes to the understanding of the x-ray source and hot electrons produced in this regime. The micron-sized lambda3 focus engenders a comparably sized x-ray source that could be attractive for high resolution x-ray imaging applications. With this in mind, the source size is measured for various target materials using the knife-edge technique. Furthermore, the source spatial coherence properties are investigated by analyzing the diffraction pattern off a straight edge. Also investigated are the spatial and energy distributions of hot electrons escaping the plasma. In the case of an Al plasma, the electrons have a Maxwellian-like energy distribution with a temperature that scales with (I lambda 2)0.6 in the 1017--2 x 10 18 W/cm2 intensity range. On the other hand, in the case of an SiO2 plasma with lambda/2 scale-length, the electrons are emitted in a collimated relativistic jet having a non-Maxwellian distribution with = 675 keV. This is the first demonstration of laser-generated relativistic electron beams at kilohertz repetition rate. Additionally, this dissertation reports on two pioneering demonstrations in a related but fundamentally different regime, that of high-average power fiber lasers. In the first experiment, Ni Kalpha x-rays are produced using a fiber CPA system at the intensity of 2 x 1018 W/cm 2, the highest reported to date from a fiber system. The conversion efficiency into the Kalpha

  9. Industrial applications of automated X-ray inspection

    Science.gov (United States)

    Shashishekhar, N.

    2015-03-01

    Many industries require that 100% of manufactured parts be X-ray inspected. Factors such as high production rates, focus on inspection quality, operator fatigue and inspection cost reduction translate to an increasing need for automating the inspection process. Automated X-ray inspection involves the use of image processing algorithms and computer software for analysis and interpretation of X-ray images. This paper presents industrial applications and illustrative case studies of automated X-ray inspection in areas such as automotive castings, fuel plates, air-bag inflators and tires. It is usually necessary to employ application-specific automated inspection strategies and techniques, since each application has unique characteristics and interpretation requirements.

  10. X-ray variability with WFXT: AGNs, transients and more

    CERN Document Server

    Paolillo, Maurizio; Allevato, Viola; de Martino, Domitilla; della Valle, Massimo; Papadakis, Iossif; Gilli, Roberto; Tozzi, Paolo

    2010-01-01

    The Wide Field X-ray Telescope (WFXT) is a proposed mission with a high survey speed, due to the combination of large field of view (FOV) and effective area, i.e. grasp, and sharp PSF across the whole FOV. These characteristics make it suitable to detect a large number of variable and transient X-ray sources during its operating lifetime. Here we present estimates of the WFXT capabilities in the time domain, allowing to study the variability of thousand of AGNs with significant detail, as well as to constrain the rates and properties of hundreds of distant, faint and/or rare objects such as X-ray Flashes/faint GRBs, Tidal Disruption Events, ULXs, Type-I bursts etc. The planned WFXT extragalactic surveys will thus allow to trace variable and transient X-ray populations over large cosmological volumes.

  11. Compton Scattering and Its Applications: The PLEIADES Femtosecond X-ray Source at LLNL

    Energy Technology Data Exchange (ETDEWEB)

    Hartemann, F V; Brown, W J; Anderson, S G; Barty, C P J; Betts, S M; Booth, R; Crane, J K; Cross, R R; Fittinghoff, D N; Gibson, D J; Kuba, J; Rupp, B; Tremaine, A M; Springer, P T

    2003-05-01

    Remarkable developments in critical technologies including terawatt-class lasers using chirped-pulse amplification, high brightness photoinjectors, high-gradient accelerators, and superconducting linacs make it possible to design and operate compact, tunable, subpicosecond Compton scattering x-ray sources with a wide variety of applications. In such novel radiation sources, the collision between a femtosecond laser pulse and a low emittance relativistic electron bunch in a small ({micro}m{sup 3}) interaction volume produces Doppler-upshifted scattered photons with unique characteristics: the energy is tunable in the 5-500 keV range, the angular divergence of the beam is small (mrad), and the pulses are ultrashort (10 fs - 10 ps). Two main paths are currently being followed in laboratories worldwide: high peak brightness, using ultrahigh intensity femtosecond lasers at modest repetition rates, and high average brightness, using superconducting linac and high average power laser technology at MHz repetition rates. Targeted applications range from x-ray protein crystallography and high contrast medical imaging to femtosecond pump-probe and diffraction experiments. More exotic uses of such sources include the {gamma}-{gamma} collider, NIF backlighting, nonlinear Compton scattering, and high-field QED. Theoretical considerations and experimental results will be discussed within this context.

  12. Compton Scattering and its Applications:. the Pleiades Femtosecond X-Ray Source at LLNL

    Science.gov (United States)

    Hartemann, F. V.; Brown, W. J.; Anderson, S. G.; Barty, C. P. J.; Betts, S. M.; Booth, R.; Crane, J. K.; Cross, R. R.; Fittinghoff, D. N.; Gibson, D. J.; Kuba, J.; Rupp, B.; Tremaine, A. M.; Springer, P. T.

    2004-10-01

    Remarkable developments in critical technologies including terawatt-class lasers using chirped-pulse amplification, high brightness photoinjectors, high-gradient accelerators, and superconducting linacs make it possible to design and operate compact, tunable, subpicosecond Compton scattering x-ray sources with a wide variety of applications. In such novel radiation sources, the collision between a femtosecond laser pulse and a low emittance relativistic electron bunch in a small (μm3) interaction volume produces Doppler-upshifted scattered photons with unique characteristics: the energy is tunable in the 5-500 keV range, the angular divergence of the beam is small (mrad), and the pulses are ultrashort (10 fs - 10 ps). Two main paths are currently being followed in laboratories worldwide: high peak brightness, using ultrahigh intensity femtosecond lasers at modest repetition rates, and high average brightness, using superconducting linac and high average power laser technology at MHz repetition rates. Targeted applications range from x-ray protein crystallography and high contrast medical imaging to femtosecond pump-probe and diffraction experiments. More exotic uses of such sources include the γ-γ collider, NIF backlighting, nonlinear Compton scattering, and high-field QED. Theoretical considerations and experimental results will be discussed within this context.

  13. X-Ray Exam: Scoliosis (For Parents)

    Science.gov (United States)

    ... Old Feeding Your 1- to 2-Year-Old X-Ray Exam: Scoliosis KidsHealth > For Parents > X-Ray Exam: Scoliosis A A A What's in ... español Radiografía: escoliosis What It Is A scoliosis X-ray is a relatively safe and painless test ...

  14. X-Ray Exam: Neck (For Parents)

    Science.gov (United States)

    ... Old Feeding Your 1- to 2-Year-Old X-Ray Exam: Neck KidsHealth > For Parents > X-Ray Exam: Neck A A A What's in ... español Radiografía: cuello What It Is A neck X-ray is a safe and painless test that ...

  15. X-Ray Exam: Femur (Upper Leg)

    Science.gov (United States)

    ... Old Feeding Your 1- to 2-Year-Old X-Ray Exam: Femur (Upper Leg) KidsHealth > For Parents > X-Ray Exam: Femur (Upper Leg) A A A ... español Radiografía: fémur What It Is A femur X-ray is a safe and painless test that ...

  16. Center for X-ray Optics, 1988

    Energy Technology Data Exchange (ETDEWEB)

    1989-04-01

    This report briefly reviews the following topics: soft-x-ray imaging; reflective optics for hard x-rays; coherent XUV sources; spectroscopy with x-rays; detectors for coronary artery imaging; synchrotron-radiation optics; and support for the advanced light source.

  17. Cryotomography x-ray microscopy state

    Science.gov (United States)

    Le Gros, Mark; Larabell, Carolyn A.

    2010-10-26

    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.

  18. FemtoSpeX: a versatile optical pump-soft X-ray probe facility with 100 fs X-ray pulses of variable polarization.

    Science.gov (United States)

    Holldack, Karsten; Bahrdt, Johannes; Balzer, Andreas; Bovensiepen, Uwe; Brzhezinskaya, Maria; Erko, Alexei; Eschenlohr, Andrea; Follath, Rolf; Firsov, Alexander; Frentrup, Winfried; Le Guyader, Loïc; Kachel, Torsten; Kuske, Peter; Mitzner, Rolf; Müller, Roland; Pontius, Niko; Quast, Torsten; Radu, Ilie; Schmidt, Jan Simon; Schüssler-Langeheine, Christian; Sperling, Mike; Stamm, Christian; Trabant, Christoph; Föhlisch, Alexander

    2014-09-01

    Here the major upgrades of the femtoslicing facility at BESSY II (Khan et al., 2006) are reviewed, giving a tutorial on how elliptical-polarized ultrashort soft X-ray pulses from electron storage rings are generated at high repetition rates. Employing a 6 kHz femtosecond-laser system consisting of two amplifiers that are seeded by one Ti:Sa oscillator, the total average flux of photons of 100 fs duration (FWHM) has been increased by a factor of 120 to up to 10(6) photons s(-1) (0.1% bandwidth)(-1) on the sample in the range from 250 to 1400 eV. Thanks to a new beamline design, a factor of 20 enhanced flux and improvements of the stability together with the top-up mode of the accelerator have been achieved. The previously unavoidable problem of increased picosecond-background at higher repetition rates, caused by `halo' photons, has also been solved by hopping between different `camshaft' bunches in a dedicated fill pattern (`3+1 camshaft fill') of the storage ring. In addition to an increased X-ray performance at variable (linear and elliptical) polarization, the sample excitation in pump-probe experiments has been considerably extended using an optical parametric amplifier that supports the range from the near-UV to the far-IR regime. Dedicated endstations covering ultrafast magnetism experiments based on time-resolved X-ray circular dichroism have been either upgraded or, in the case of time-resolved resonant soft X-ray diffraction and reflection, newly constructed and adapted to femtoslicing requirements. Experiments at low temperatures down to 6 K and magnetic fields up to 0.5 T are supported. The FemtoSpeX facility is now operated as a 24 h user facility enabling a new class of experiments in ultrafast magnetism and in the field of transient phenomena and phase transitions in solids.

  19. Table-top laser-driven ultrashort electron and X-ray source: the CIBER-X source project

    Science.gov (United States)

    Girardeau-Montaut, Jean-Pierre; Kiraly, Bélà; Girardeau-Montaut, Claire; Leboutet, Hubert

    2000-09-01

    We report on the development of a new laser-driven table-top ultrashort electron and X-ray source, also called the CIBER-X source . X-ray pulses are produced by a three-step process which consists of the photoelectron emission from a thin metallic photocathode illuminated by 16 ps duration laser pulses at 213 nm. The e-gun is a standard Pierce diode electrode type, in which electrons are accelerated by a cw electric field of ˜11 MV/m up to a hole made in the anode. The photoinjector produces a train of 70-80 keV electron pulses of ˜0.5 nC and 20 A peak current at a repetition rate of 10 Hz. The electrons are then transported outside the diode along a path of 20 cm length, and are focused onto a target of thullium by magnetic fields produced by two electromagnetic coils. X-rays are then produced by the impact of electrons on the target. Simulations of geometrical, electromagnetic fields and energetic characteristics of the complete source were performed previously with the assistance of the code PIXEL1 also developed at the laboratory. Finally, experimental electron and X-ray performances of the CIBER-X source as well as its application to very low dose imagery are presented and discussed. source Compacte d' Impulsions Brèves d' Electrons et de Rayons X

  20. RS Ophiuchi in Quiescence: Why is it X-ray Faint?

    CERN Document Server

    Mukai, Koji

    2008-01-01

    The short interval between successive outbursts of RS Oph strongly suggests that it has a high mass white dwarf accreting at a high rate. This, in turn, suggests the possibility of prominent X-ray emission from RS Oph in quiescence. However, archival quiescent X-ray observations of RS Oph show it to be a modest soft X-ray source but not a strong 2-10 keV X-ray source. In this aspect, RS Oph differs markedly from T CrB. We speculate on the possible mechanisms that could significantly suppress the 2-10 keV X-ray emission in RS Oph.

  1. X-Ray Visions of SS Cygni

    Science.gov (United States)

    Young, D. L.

    2004-12-01

    The Chandra X-Ray Observatory is the most sophisticated X-ray observatory launched by NASA. Chandra is designed to observe X-rays from highenergy regions of the universe, such as X-ray binary stars. On September 14, 2000, triggered by alerts from amateur astronomers worldwide, Chandra observed the outburst of the brightest northern dwarf nova SS Cygni. The cooperation of hundreds of amateur variable star astronomers and the Chandra X-Ray scientists and spacecraft specialists provided proof that the collaboration of amateur and professional astronomers is a powerful tool to study cosmic phenomena.

  2. X-ray Spectroscopy of Cooling Cluster

    Energy Technology Data Exchange (ETDEWEB)

    Peterson, J.R.; /SLAC; Fabian, A.C.; /Cambridge U., Inst. of Astron.

    2006-01-17

    We review the X-ray spectra of the cores of clusters of galaxies. Recent high resolution X-ray spectroscopic observations have demonstrated a severe deficit of emission at the lowest X-ray temperatures as compared to that expected from simple radiative cooling models. The same observations have provided compelling evidence that the gas in the cores is cooling below half the maximum temperature. We review these results, discuss physical models of cooling clusters, and describe the X-ray instrumentation and analysis techniques used to make these observations. We discuss several viable mechanisms designed to cancel or distort the expected process of X-ray cluster cooling.

  3. Comets: mechanisms of x-ray activity

    Science.gov (United States)

    Ibadov, Subhon

    2016-07-01

    Basic mechanisms of X-ray activity of comets are considered, including D-D mechanism corresponding to generation of X-rays due to production of hot short-living plasma clumps at high-velocity collisions between cometary and interplanetary dust particles as well as M-M one corresponding to production of X-rays due to recombination of multicharge ions of solar wind plasma via charge exchange process at their collisions with molecules/atoms of the cometary atmospheres. Peculiarities of the variation of the comet X-ray spectrum and X-ray luminosity with variation of its heliocentric distance are revealed.

  4. Obtaining high degree of circular polarization at X-ray FELs via a reverse undulator taper

    Energy Technology Data Exchange (ETDEWEB)

    Schneidmiller, E.A.; Yurkov, M.V.

    2013-08-15

    Baseline design of a typical X-ray FEL undulator assumes a planar configuration which results in a linear polarization of the FEL radiation. However, many experiments at X-ray FEL user facilities would profit from using a circularly polarized radiation. As a cheap upgrade one can consider an installation of a short helical (or cross-planar) afterburner, but then one should have an efficient method to suppress powerful linearly polarized background from the main undulator. In this paper we propose a new method for such a suppression: an application of the reverse taper in the main undulator. We discover that in a certain range of the taper strength, the density modulation (bunching) at saturation is practically the same as in the case of non-tapered undulator while the power of linearly polarized radiation is suppressed by orders of magnitude. Then strongly modulated electron beam radiates at full power in the afterburner. Considering SASE3 undulator of the European XFEL as a practical example, we demonstrate that soft X-ray radiation pulses with peak power in excess of 100 GW and an ultimately high degree of circular polarization can be produced. The proposed method is rather universal, i.e. it can be used at SASE FELs and seeded (self-seeded) FELs, with any wavelength of interest, in a wide range of electron beam parameters, and with any repetition rate. It can be used at different X-ray FEL facilities, in particular at LCLS after installation of the helical afterburner in the near future.

  5. A laser driven pulsed X-ray backscatter technique for enhanced penetrative imaging.

    Science.gov (United States)

    Deas, R M; Wilson, L A; Rusby, D; Alejo, A; Allott, R; Black, P P; Black, S E; Borghesi, M; Brenner, C M; Bryant, J; Clarke, R J; Collier, J C; Edwards, B; Foster, P; Greenhalgh, J; Hernandez-Gomez, C; Kar, S; Lockley, D; Moss, R M; Najmudin, Z; Pattathil, R; Symes, D; Whittle, M D; Wood, J C; McKenna, P; Neely, D

    2015-01-01

    X-ray backscatter imaging can be used for a wide range of imaging applications, in particular for industrial inspection and portal security. Currently, the application of this imaging technique to the detection of landmines is limited due to the surrounding sand or soil strongly attenuating the 10s to 100s of keV X-rays required for backscatter imaging. Here, we introduce a new approach involving a 140 MeV short-pulse (laser wakefield acceleration to probe the sample, which produces Bremsstrahlung X-rays within the sample enabling greater depths to be imaged. A variety of detector and scintillator configurations are examined, with the best time response seen from an absorptive coated BaF2 scintillator with a bandpass filter to remove the slow scintillation emission components. An X-ray backscatter image of an array of different density and atomic number items is demonstrated. The use of a compact laser wakefield accelerator to generate the electron source, combined with the rapid development of more compact, efficient and higher repetition rate high power laser systems will make this system feasible for applications in the field. Content includes material subject to Dstl (c) Crown copyright (2014). Licensed under the terms of the Open Government Licence except where otherwise stated. To view this licence, visit http://www.nationalarchives.gov.uk/doc/open-government-licence/version/3 or write to the Information Policy Team, The National Archives, Kew, London TW9 4DU, or email: psi@ nationalarchives.gsi.gov.uk.

  6. Design of a radiation hard silicon pixel sensor for X-ray science

    Energy Technology Data Exchange (ETDEWEB)

    Schwandt, Joern

    2014-06-15

    At DESY Hamburg the European X-ray Free-Electron Laser (EuXFEL) is presently under construction. The EuXFEL has unique properties with respect to X-ray energy, instantaneous intensity, pulse length, coherence and number of pulses/sec. These properties of the EuXFEL pose very demanding requirements for imaging detectors. One of the detector systems which is currently under development to meet these challenges is the Adaptive Gain Integrating Pixel Detector, AGIPD. It is a hybrid pixel-detector system with 1024 x 1024 p{sup +} pixels of dimensions 200 μm x 200 μm, made of 16 p{sup +}nn{sup +}- silicon sensors, each with 10.52 cm x 2.56 cm sensitive area and 500 μm thickness. The particular requirements for the AGIPD are a separation between noise and single photons down to energies of 5 keV, more than 10{sup 4} photons per pixel for a pulse duration of less than 100 fs, negligible pile-up at the EuXFEL repetition rate of 4.5 MHz, operation for X-ray doses up to 1 GGy, good efficiency for X-rays with energies between 5 and 20 keV, and minimal inactive regions at the edges. The main challenge in the sensor design is the required radiation tolerance and high operational voltage, which is required to reduce the so-called plasma effect. This requires a specially optimized sensor. The X-ray radiation damage results in a build-up of oxide charges and interface traps which lead to a reduction of the breakdown voltage, increased leakage current, increased interpixel capacitances and charge losses. Extensive TCAD simulations have been performed to understand the impact of X-ray radiation damage on the detector performance and optimize the sensor design. To take radiation damage into account in the simulation, radiation damage parameters have been determined on MOS capacitors and gate-controlled diodes as function of dose. The optimized sensor design was fabricated by SINTEF. Irradiation tests on test structures and sensors show that the sensor design is radiation hard and

  7. X-rays from solar system objects

    CERN Document Server

    Bhardwaj, Anil; Gladstone, G Randall; Cravens, Thomas E; Lisse, Carey M; Dennerl, Konrad; Branduardi-Raymont, Graziella; Wargelin, Bradford J; Waite, J Hunter; Robertson, Ina; Ostgaard, Nikolai; Beiersdorfer, Peter; Snowden, Steven L; Kharchenko, Vasili; 10.1016/j.pss.2006.11.009

    2010-01-01

    During the last few years our knowledge about the X-ray emission from bodies within the solar system has significantly improved. Several new solar system objects are now known to shine in X-rays at energies below 2 keV. Apart from the Sun, the known X-ray emitters now include planets (Venus, Earth, Mars, Jupiter, and Saturn), planetary satellites (Moon, Io, Europa, and Ganymede), all active comets, the Io plasma torus (IPT), the rings of Saturn, the coronae (exospheres) of Earth and Mars, and the heliosphere. The advent of higher-resolution X-ray spectroscopy with the Chandra and XMM-Newton X-ray observatories has been of great benefit in advancing the field of planetary X-ray astronomy. Progress in modeling X-ray emission, laboratory studies of X-ray production, and theoretical calculations of cross-sections, have all contributed to our understanding of processes that produce X-rays from the solar system bodies. At Jupiter and Earth, both auroral and non-auroral disk X-ray emissions have been observed. X-ray...

  8. Phase-contrast X-ray CT

    Energy Technology Data Exchange (ETDEWEB)

    Momose, Atsushi [Hitachi Ltd., Hatoyama, Saitama (Japan). Advanced Research Lab.

    1996-08-01

    X-ray transmission imaging that creates image contrast from the distribution of the X-ray absorption coefficient is not sensitive to materials consisting of light elements such as hydrogen, carbon, nitrogen, and oxygen. On the other hand, the X-ray phase shift caused by the light elements is substantial enough to be detected even when absorption is almost zero. Hence, phase-contrast X-ray imaging is a promising technique for observing the structure inside biological soft tissues without the need for staining and without serious radiation exposure. Using fringe scanning X-ray interferometry, the X-ray phase shift caused by an object was measured. Three-dimensional image reconstruction of cancerous tissues using the measured phase shifts was enabled under tomographic configuration phase-contrast X-ray computed tomography (CT). (author)

  9. On the X-ray heated skin of Accretion Disks

    CERN Document Server

    Nayakshin, S

    1999-01-01

    We present a simple analytical formula for the Thomson depth of the X-rayheated skin of accretion disks valid at any radius and for a broad range ofspectral indices of the incident X-rays, accretion rates and black hole masses.We expect that this formula may find useful applications in studies of geometryof the inner part of accretion flows around compact objects, and in severalother astrophysically important problems, such as the recently observed X-ray``Baldwin'' effect (i.e., monotonic decrease of Fe line's equivalent width withthe X-ray luminosity of AGN), the problem of missing Lyman edge in AGN, andline and continuum variability studies in accretion disks around compactobjects. We compute the reflected X-ray spectra for several representativecases and show that for hard X-ray spectra and large ionizing fluxes the skinrepresents a perfect mirror that does not produce any Fe lines or absorptionfeatures. At the same time, for soft X-ray spectra or small ionizing fluxes,the skin produces very strong ionized...

  10. The Decay of Stellar Dynamos and X-ray Activity

    CERN Document Server

    Wright, Nicholas J; Civano, Francesca

    2010-01-01

    Existing stellar X-ray surveys suggest major problems in our understanding of the evolution of stellar magnetic activity in solar and late-type stars, reaching conflicting conclusions over the rate of decay of X-ray activity and the spectral types responsible. We are confronting these discrepancies with a new model of the expected stellar X-ray luminosity distribution, combining a Galactic population synthesis model with current theories for rotational spin- down and the rotation - activity relation for the stellar magnetic dynamo. Here we test our model using new observations of the stellar content of the Chandra COSMOS survey, for which 60 new stellar X-ray sources are identified from the thin disk and Galactic halo populations. Our model is in approximate agreement with the observed X-ray luminosity distribution and the distribution of spectral types responsible. However, slight differences in the form of the X-ray luminosity distribution exist that may hint at problems in our understanding of stellar X-ra...

  11. Pulse-periodic generation of supershort avalanche electron beams and X-ray emission

    Science.gov (United States)

    Baksht, E. Kh.; Burachenko, A. G.; Erofeev, M. V.; Tarasenko, V. F.

    2014-05-01

    Pulse-periodic generation of supershort avalanche electron beams (SAEBs) and X-ray emission in nitrogen, as well as the transition from a single-pulse mode to a pulse-periodic mode with a high repetition frequency, was studied experimentally. It is shown that, in the pulse-periodic mode, the full width at halfmaximum of the SAEB is larger and the decrease rate of the gap voltage is lower than those in the single-pulse mode. It is found that, when the front duration of the voltage pulse at a nitrogen pressure of 90 Torr decreases from 2.5 to 0.3 ns, the X-ray exposure dose in the pulse-periodic mode increases by more than one order of magnitude and the number of SAEB electrons also increases. It is shown that, in the pulse-periodic mode of a diffuse discharge, gas heating in the discharge gap results in a severalfold increase in the SAEB amplitude (the number of electrons in the beam). At a generator voltage of 25 kV, nitrogen pressure of 90 Torr, and pulse repetition frequency of 3.5 kHz, a runaway electron beam was detected behind the anode foil.

  12. Switchable repetition rate bound solitons passively mode-locked fiber laser

    Science.gov (United States)

    Wang, Xuqin; Yao, Yong

    2016-11-01

    We present a kind of a switchable repetition rate mode-locked of bound-state solitons in a fiber laser based on Bi2Se3 saturable absorber (SA). In the fiber laser, two forms of the bound-state optical spectrum with central wavelength of 1532 nm are observed. The fiber laser is operate at the abnormal group velocity dispersion and the bound state pulses are equally distributed to the temporal domain. The fundamental cavity repetition-rate is 1.11 MHz with a pulse duration of 2.27 ps. The output average power and the pulse peak energy are 1.53 mW and 607 W respectively, which the pump power is 267 mW. The different repetition-rates are also achieved by changing the pump power or adjusting the angle of polarization controller. In the experiment, the repetition-rate is switched from 1.11 MHz to 41.32 MHz (37th-order, the highest repetition-rate).

  13. Full-field transmission x-ray imaging with confocal polycapillary x-ray optics.

    Science.gov (United States)

    Sun, Tianxi; Macdonald, C A

    2013-02-07

    A transmission x-ray imaging setup based on a confocal combination of a polycapillary focusing x-ray optic followed by a polycapillary collimating x-ray optic was designed and demonstrated to have good resolution, better than the unmagnified pixel size and unlimited by the x-ray tube spot size. This imaging setup has potential application in x-ray imaging for small samples, for example, for histology specimens.

  14. 53 W average power few-cycle fiber laser system generating soft x rays up to the water window.

    Science.gov (United States)

    Rothhardt, Jan; Hädrich, Steffen; Klenke, Arno; Demmler, Stefan; Hoffmann, Armin; Gotschall, Thomas; Eidam, Tino; Krebs, Manuel; Limpert, Jens; Tünnermann, Andreas

    2014-09-01

    We report on a few-cycle laser system delivering sub-8-fs pulses with 353 μJ pulse energy and 25 GW of peak power at up to 150 kHz repetition rate. The corresponding average output power is as high as 53 W, which represents the highest average power obtained from any few-cycle laser architecture so far. The combination of both high average and high peak power provides unique opportunities for applications. We demonstrate high harmonic generation up to the water window and record-high photon flux in the soft x-ray spectral region. This tabletop source of high-photon flux soft x rays will, for example, enable coherent diffractive imaging with sub-10-nm resolution in the near future.

  15. Energy dispersive x-ray fluorescence analyzer with several x-ray tubes

    Science.gov (United States)

    Borisov, G. I.; Kondratenko, R. I.; Mikhin, V. A.; Odinov, B. V.; Pukhov, A. V.

    2005-07-01

    X-ray flurescent analyzer (XFA) has been developed and fabricated for determining sulphur, vanadium and nickel in oil. The instrument is equipped with three x-ray tubes with transmission Ti, Cu and Ag anodes, and aluminum, copper, and germanium filters, respectively, and one common switchable power supply. To excite characteristic radiation of determined elements, the characteristic radiation of the tube anode (titan, copper) is used, or the charactersitic radiation of the filter (germanium). XFA is fitted with one small-size electrically cooled semiconductor detector. The measuring device is based on a wide-angle geometry of characteristic radiation excitation and registration, where the x-ray tube focus illuminates the sample, and the registering detector 'sees' the illuminated area within the plane angle of 90° (it corresponds to 0.146 of 4p). Under such geometry, the dependence of the count rate for excited characteristic photons on the position of sample under study has a smooth maximum in the calculated sample position point. For one, the rate count changes by less than 1%. Quantitative results are obtained through the regression method. The instrument underwent metrology testing. It is designed for operation both in the laboratory and industrial environment. The instrument has been delivered for operation to the "Druzhba" pipeline.

  16. X-RAY EMISSION FROM MAGNETIC MASSIVE STARS

    Energy Technology Data Exchange (ETDEWEB)

    Nazé, Yaël [GAPHE, Département AGO, Université de Liège, Allée du 6 Août 17, Bat. B5C, B-4000 Liège (Belgium); Petit, Véronique [Department of Physics and Space Sciences, Florida Institute of Technology, Melbourne, FL 32901 (United States); Rinbrand, Melanie; Owocki, Stan [Department of Physics and Astronomy, University of Delaware, Bartol Research Institute, Newark, DE 19716 (United States); Cohen, David [Department of Physics and Astronomy, Swarthmore College, Swarthmore, PA 19081 (United States); Ud-Doula, Asif [Penn State Worthington Scranton, Dunmore, PA 18512 (United States); Wade, Gregg A., E-mail: naze@astro.ulg.ac.be [Department of Physics, Royal Military College of Canada, PO Box 17000, Station Forces, Kingston, ON K7K 4B4 (Canada)

    2014-11-01

    Magnetically confined winds of early-type stars are expected to be sources of bright and hard X-rays. To clarify the systematics of the observed X-ray properties, we have analyzed a large series of Chandra and XMM-Newton observations, corresponding to all available exposures of known massive magnetic stars (over 100 exposures covering ∼60% of stars compiled in the catalog of Petit et al.). We show that the X-ray luminosity is strongly correlated with the stellar wind mass-loss rate, with a power-law form that is slightly steeper than linear for the majority of the less luminous, lower- M-dot B stars and flattens for the more luminous, higher- M-dot O stars. As the winds are radiatively driven, these scalings can be equivalently written as relations with the bolometric luminosity. The observed X-ray luminosities, and their trend with mass-loss rates, are well reproduced by new MHD models, although a few overluminous stars (mostly rapidly rotating objects) exist. No relation is found between other X-ray properties (plasma temperature, absorption) and stellar or magnetic parameters, contrary to expectations (e.g., higher temperature for stronger mass-loss rate). This suggests that the main driver for the plasma properties is different from the main determinant of the X-ray luminosity. Finally, variations of the X-ray hardnesses and luminosities, in phase with the stellar rotation period, are detected for some objects and they suggest that some temperature stratification exists in massive stars' magnetospheres.

  17. X-Ray Attenuation Cell

    Energy Technology Data Exchange (ETDEWEB)

    Ryutov, D.; Toor, A.

    2000-03-03

    To minimize the pulse-to-pulse variation, the LCLS FEL must operate at saturation, i.e. 10 orders of magnitude brighter spectral brilliance than 3rd-generation light sources. At this intensity, ultra-high vacuums and windowless transport are required. Many of the experiments, however, will need to be conducted at a much lower intensity thereby requiring a reliable means to reduce the x-ray intensity by many orders of magnitude without increasing the pulse-to-pulse variation. In this report we consider a possible solution for controlled attenuation of the LCLS x-ray radiation. We suggest using for this purpose a windowless gas-filled cell with the differential pumping. Although this scheme is easily realizable in principle, it has to be demonstrated that the attenuator can be made short enough to be practical and that the gas loads delivered to the vacuum line of sight (LOS) are acceptable. We are not going to present a final, optimized design. Instead, we will provide a preliminary analysis showing that the whole concept is robust and is worth further study. The spatial structure of the LCLS x-ray pulse at the location of the attenuator is shown in Fig. 1. The central high-intensity component, due to the FEL, has a FWHM of {approx}100 {micro}m. A second component, due to the undulator's broad band spontaneous radiation is seen as a much lower intensity ''halo'' with a FWHM of 1 mm. We discuss two versions of the attenuation cell. The first is directed towards a controlled attenuation of the FEL up to the 4 orders of magnitude in the intensity, with the spontaneous radiation halo being eliminated by collimators. In the second version, the spontaneous radiation is not sacrificed but the FEL component (as well as the first harmonic of the spontaneous radiation) gets attenuated by a more modest factor up to 100. We will make all the estimates assuming that the gas used in the attenuator is Xenon and that the energy of the FEL is 8.25 keV. At

  18. Multi-Rate Fractional-Order Repetitive Control of Shunt Active Power Filter

    DEFF Research Database (Denmark)

    Xie, Chuan; Zhao, Xin; Savaghebi, Mehdi

    2017-01-01

    This paper presents a multi-rate fractional-order repetitive control (MRFORC) scheme for three-phase shunt active power filter (APF). The proposed APF control scheme includes an inner proportional-integral (PI) control loop with a sampling rate identical to switching frequency and an external plug-in...

  19. Design and First Tests of a Radiation-Hard Pixel Sensor for the European X-Ray Free-Electron Laser

    CERN Document Server

    Schwandt, Joern; Klanner, Robert; Kopsalis, Ioannis; Zhang, Jiaguo

    2014-01-01

    The high intensity and high repetition rate of the European X-ray Free-Electron Laser, presently under construction in Hamburg, requires silicon sensors which can stand X-ray doses of up to 1 GGy for 3 years of operation at high bias voltage. Within the AGIPD Collaboration the X-ray-radiation damage in MOS Capacitors and Gate-Controlled Diodes fabricated by four vendors on high-ohmic n-type silicon with two crystal orientations and dif- ferent technological parameters, has been studied for doses between 1 kGy and 1 GGy. The extracted values of oxide-charge and surface-current densi- ties have been used in TCAD simulations, and the layout and technological parameters of the AGIPD pixel sensor optimized. It is found that the op- timized layout for high X-ray doses is significantly different from the one for non-irradiated sensors. First sensors and test structures have been de-livered in early 2013. Measurement results for X-ray doses of 0 to 10 MGy and their comparison to simulations are presented. They demons...

  20. Near- infrared, mode-locked waveguide lasers with multi-GHz repetition rates

    Science.gov (United States)

    Choudhary, A.; Lagatsky, A. A.; Zhang, Z. Y.; Zhou, K. J.; Wang, Q.; Hogg, R. A.; Pradeesh, K.; Rafailov, E. U.; Resan, B.; Oehler, A. E. H.; Weingarten, K. J.; Sibbett, W.; Brown, C. T. A.; Shepherd, D. P.

    2014-02-01

    In this work, we discuss mode-locking results obtained with low-loss, ion-exchanged waveguide lasers. With Yb3+-doped phosphate glass waveguide lasers, a repetition rate of up to 15.2 GHz was achieved at a wavelength of 1047 nm with an average power of 27 mW and pulse duration of 811 fs. The gap between the waveguide and the SESAM introduced negative group velocity dispersion via the Gires Tournois Interferometer (GTI) effect which allowed the soliton mode-locking of the device. A novel quantum dot SESAM was used to mode-lock Er3+, Yb3+-doped phosphate glass waveguide lasers around 1500 nm. Picosecond pulses were achieved at a maximum repetition rate of 6.8 GHz and an average output power of 30 mW. The repetition rate was tuned by more than 1 MHz by varying the pump power.

  1. Controlling X-rays With Light

    Energy Technology Data Exchange (ETDEWEB)

    Glover, Ernie; Hertlein, Marcus; Southworth, Steve; Allison, Tom; van Tilborg, Jeroen; Kanter, Elliot; Krassig, B.; Varma, H.; Rude, Bruce; Santra, Robin; Belkacem, Ali; Young, Linda

    2010-08-02

    Ultrafast x-ray science is an exciting frontier that promises the visualization of electronic, atomic and molecular dynamics on atomic time and length scales. A largelyunexplored area of ultrafast x-ray science is the use of light to control how x-rays interact with matter. In order to extend control concepts established for long wavelengthprobes to the x-ray regime, the optical control field must drive a coherent electronic response on a timescale comparable to femtosecond core-hole lifetimes. An intense field is required to achieve this rapid response. Here an intense optical control pulse isobserved to efficiently modulate photoelectric absorption for x-rays and to create an ultrafast transparency window. We demonstrate an application of x-ray transparencyrelevant to ultrafast x-ray sources: an all-photonic temporal cross-correlation measurement of a femtosecond x-ray pulse. The ability to control x-ray/matterinteractions with light will create new opportunities at current and next-generation x-ray light sources.

  2. Single Longitudinal Mode, High Repetition Rate, Q-switched Ho:YLF Laser for Remote Sensing

    Science.gov (United States)

    Bai, Yingxin; Yu, Jirong; Petzar, Paul; Petros, M.; Chen, Songsheng; Trieu, Bo; Lee, Nyung; Singh, U.

    2009-01-01

    Ho:YLF/LuLiF lasers have specific applications for remote sensing such as wind-speed measurement and carbon dioxide (CO2) concentration measurement in the atmosphere because the operating wavelength (around 2 m) is located in the eye-safe range and can be tuned to the characteristic lines of CO2 absorption and there is strong backward scattering signal from aerosol (Mie scattering). Experimentally, a diode pumped Ho:Tm:YLF laser has been successfully used as the transmitter of coherent differential absorption lidar for the measurement of with a repetition rate of 5 Hz and pulse energy of 75 mJ [1]. For highly precise CO2 measurements with coherent detection technique, a laser with high repetition rate is required to averaging out the speckle effect [2]. In addition, laser efficiency is critically important for the air/space borne lidar applications, because of the limited power supply. A diode pumped Ho:Tm:YLF laser is difficult to efficiently operate in high repetition rate due to the large heat loading and up-conversion. However, a Tm:fiber laser pumped Ho:YLF laser with low heat loading can be operated at high repetition rates efficiently [3]. No matter whether wind-speed or carbon dioxide (CO2) concentration measurement is the goal, a Ho:YLF/LuLiF laser as the transmitter should operate in a single longitudinal mode. Injection seeding is a valid technique for a Q-switched laser to obtain single longitudinal mode operation. In this paper, we will report the new results for a single longitudinal mode, high repetition rate, Q-switched Ho:YLF laser. In order to avoid spectral hole burning and make injection seeding easier, a four mirror ring cavity is designed for single longitudinal mode, high repetition rate Q-switched Ho:YLF laser. The ramp-fire technique is chosen for injection seeding.

  3. High repetition rate passively Q-switched fiber and microchip lasers for optical resolution photoacoustic imaging

    Science.gov (United States)

    Shi, Wei; Utkin, Ilya; Ranasinghesagara, Janaka; Pan, Lei; Godwal, Yogesh; Kerr, Shaun; Zemp, Roger J.; Fedosejevs, Robert

    2010-02-01

    Optical-resolution photoacoustic microscopy is a novel imaging technology for visualizing optically-absorbing superficial structures in vivo with lateral spatial resolution determined by optical focusing rather than acoustic detection. Since scanning of the illumination spot is required, the imaging speed is limited by the scanning speed and the laser pulse repetition rate. Unfortunately, lasers with high-repetition rate and suitable pulse durations and energies are difficult to find. We are developing compact laser sources for this application. Passively Q-switched fiber and microchip lasers with pulse repetition rates up to 300 kHz are demonstrated. Using a diode-pumped microchip laser fiber-coupled to a large mode-area Yb-doped fiber amplifier we obtained 60μJ 1-ns pulses at the frequency-doubled 532-nm wavelength. The pulse-repetition rate was determined by the power of the microchip laser pump source at 808nm and may exceed 10 kHz. Additionally, a passively Q-switched fiber laser utilizing a Yb-doped double-cladding fiber and an external saturable absorber has shown to produce 250ns pulses at repetition rates of 100-300 KHz. A photoacoustic probe enabling flexible scanning of the focused output of these lasers consisted of a 45-degree glass prism in an optical index-matching fluid. Photoacoustic signals exiting the sample are deflected by the prism to an ultrasound transducer. Phantom studies with a 7.5-micron carbon fiber demonstrate the ability to image with optical rather than acoustic resolution. We believe that the high pulse-repetition rates and the potentially compact and fiber-coupled nature of these lasers will prove important for clinical imaging applications where realtime imaging performance is essential.

  4. Diffractive X-Ray Telescopes

    Science.gov (United States)

    Skinner, Gerald K.

    2010-01-01

    Diffractive X-ray telescopes, using zone plates, phase Fresnel lenses, or related optical elements have the potential to provide astronomers with true imaging capability with resolution many orders of magnitude better than available in any other waveband. Lenses that would be relatively easy to fabricate could have an angular resolution of the order of micro-arc-seconds or even better, that would allow, for example, imaging of the distorted spacetime in the immediate vicinity of the super-massive black holes in the center of active galaxies. What then is precluding their immediate adoption? Extremely long focal lengths, very limited bandwidth, and difficulty stabilizing the image are the main problems. The history, and status of the development of such lenses is reviewed here and the prospects for managing the challenges that they present are discussed.

  5. Diffractive X-ray Telescopes

    CERN Document Server

    Skinner, Gerald K

    2010-01-01

    Diffractive X-ray telescopes using zone plates, phase Fresnel lenses, or related optical elements have the potential to provide astronomers with true imaging capability with resolution several orders of magnitude better than available in any other waveband. Lenses that would be relatively easy to fabricate could have an angular resolution of the order of micro-arc-seconds or even better, that would allow, for example, imaging of the distorted space- time in the immediate vicinity of the super-massive black holes in the center of active galaxies What then is precluding their immediate adoption? Extremely long focal lengths, very limited bandwidth, and difficulty stabilizing the image are the main problems. The history, and status of the development of such lenses is reviewed here and the prospects for managing the challenges that they present are discussed.

  6. X-ray emission from Saturn

    CERN Document Server

    Ness, J U; Wolk, S J; Dennerl, K; Burwitz, V

    2004-01-01

    We report the first unambiguous detection of X-ray emission originating from Saturn with a Chandra observation, duration 65.5 ksec with ACIS-S3. Beyond the pure detection we analyze the spatial distribution of X-rays on the planetary surface, the light curve, and some spectral properties. The detection is based on 162 cts extracted from the ACIS-S3 chip within the optical disk of Saturn. We found no evidence for smaller or larger angular extent. The expected background level is 56 cts, i.e., the count rate is (1.6 +- 0.2) 10^-3 cts/s. The extracted photons are rather concentrated towards the equator of the apparent disk, while both polar caps have a relative photon deficit. The inclination angle of Saturn during the observation was -27 degrees, so that the northern hemisphere was not visible during the complete observation. In addition, it was occulted by the ring system. We found a small but significant photon excess at one edge of the ring system. The light curve shows a small dip twice at identical phases,...

  7. A contactless microwave-based diagnostic tool for high repetition rate laser systems

    CERN Document Server

    Braggio, C

    2014-01-01

    We report on a novel electro-optic device for the diagnostics of high repetition rate laser systems. It is composed of a microwave receiver and of a second order nonlinear crystal, whose irradiation with a train of short laser pulses produces a time-dependent polarization in the crystal itself as a consequence of optical rectification. This process gives rise to the emission of microwave radiation that is detected by a receiver and is analyzed to infer the repetition rate and intensity of the pulses. We believe that this new method may overcome some of the limitations of photodetection techniques.

  8. High power, high repetition rate, few picosecond Nd:LuVO₄ oscillator with cavity dumping.

    Science.gov (United States)

    Gao, Peng; Guo, Jie; Li, Jinfeng; Lin, Hua; Yu, Haohai; Zhang, Huaijin; Liang, Xiaoyan

    2015-12-28

    We investigate the potential use of Nd:LuVO4 in high average power, high repetition rate ultrafast lasers. Maximum mode-locked average power of 28 W is obtained at the repetition rate of 58 MHz. The shortest pulse duration is achieved at 4 ps without dispersion compensation. With a cavity dumping technique, the pulse energy is scaling up to 40.7 μJ at 300 kHz and 14.3 μJ at 1.5 MHz.

  9. Low-loss waveguides fabricated in BK7 glass by high repetition rate femtosecond fiber laser.

    Science.gov (United States)

    Eaton, Shane M; Ng, Mi Li; Bonse, Jörn; Mermillod-Blondin, Alexandre; Zhang, Haibin; Rosenfeld, Arkadi; Herman, Peter R

    2008-04-20

    For the first time femtosecond-laser writing has inscribed low-loss optical waveguides in Schott BK7 glass, a commercially important type of borosilicate widely used in optical applications. The use of a variable repetition rate laser enabled the identification of a narrow processing window at 1 MHz repetition rate with optimal waveguides exhibiting propagation losses of 0.3 dB/cm and efficient mode matching to standard optical fibers at a 1550 nm wavelength. The waveguides were characterized by complementary phase contrast and optical transmission microscopy, identifying a micrometer-sized guiding region within a larger complex structure of both positive and negative refractive index variations.

  10. High-q microring resonator with narrow free spectral range for pulse repetition rate multiplication

    DEFF Research Database (Denmark)

    Pu, Minhao; Ji, Hua; Frandsen, Lars Hagedorn

    2009-01-01

    We demonstrate a silicon-on-insulator microring resonator with a free-spectral-range of 0.32 nm, an extinction ratio of 27 dB, and a quality factor of ~140900 at 1550 nm that is used for pulse repetition-rate multiplication from 10 to 40 GHz.......We demonstrate a silicon-on-insulator microring resonator with a free-spectral-range of 0.32 nm, an extinction ratio of 27 dB, and a quality factor of ~140900 at 1550 nm that is used for pulse repetition-rate multiplication from 10 to 40 GHz....

  11. Programmable Control of the Pulse Repetition Rate in the Multiwave Strontium Vapor Laser System

    Directory of Open Access Journals (Sweden)

    Soldatov Anatoly

    2016-01-01

    Full Text Available The aim of the present work was the development of laser systems for ablation of biological tissues with a programmable control over the lasing pulse repetition rate in a wide range. A two-stage laser system consisting of a master oscillator and a power amplifier based on strontium vapor laser has been developed. The operation of the laser system in a single-pulse mode operation, multipulse mode operation, and with a pulse repetition rate up to 20 kHz has been technically implemented. The possibility of a bone tissue ablation with no visible thermal damage is shown.

  12. Injector Beam Dynamics for a High-Repetition Rate 4th-Generation Light Source

    Energy Technology Data Exchange (ETDEWEB)

    Papadopoulos, C. F.; Corlett, J.; Emma, P.; Filippetto, D.; Penn, G.; Qiang, J.; Reinsch, M.; Sannibale, F.; Steier, C.; Venturini, M.; Wells, R.

    2013-05-20

    We report on the beam dynamics studies and optimization methods for a high repetition rate (1 MHz) photoinjector based on a VHF normal conducting electron source. The simultaneous goals of beamcompression and reservation of 6-dimensional beam brightness have to be achieved in the injector, in order to accommodate a linac driven FEL light source. For this, a parallel, multiobjective optimization algorithm is used. We discuss the relative merits of different injector design points, as well as the constraints imposed on the beam dynamics by technical considerations such as the high repetition rate.

  13. Characterization of New Hard X-ray Cataclysmic Variables

    Science.gov (United States)

    Bernardini, F.; deMartino, D.; Falanga, M.; Mukai, K.; Matt, G.; Bonnet-Bidaud, J.-M.; Masetti, N.; Mouchet, M.

    2012-01-01

    Aims. We aim at characterizing a sample of nine new hard X-ray selected Cataclysmic Variable (CVs), to unambiguously identify them as magnetic systems of the Intermediate Polar (IP) type. Methods. We performed detailed timing and spectral analysis by using X-ray, and simultaneous UV and optical data collected by XMM-Newton, complemented with hard X-ray data provided by INTEGRAL and Swift. The pulse arrival time were used to estimate the orbital periods. The broad band X-ray spectra were fitted using composite models consisting of different absorbing columns and emission components. Results. Strong X-ray pulses at the White Dwarf (WD) spin period are detected and found to decrease with energy. Most sources are spin-dominated systems in the X-rays, though four are beat dominated at optical wavelengths. We estimated the orbital period in all system (except for IGR J16500-3307), providing the first estimate for IGRJ08390-4833, IGRJ18308-1232, and IGR J18173-2509. All X-ray spectra are multi-temperature. V2069 Cyg and RX J0636+3535 poses a soft X-ray optically thick component at kT approx. 80 eV. An intense K (sub alpha) Fe line at 6.4 keV is detected in all sources. An absorption edge at 0.76 keV from OVII is detected in IGR J08390-4833. The WD masses and lower limits to the accretion rates are also estimated. Conclusions. We found all sources to be IPs. IGR J08390-4833, V2069 Cyg, and IGR J16500-3307 are pure disc accretors, while IGR J18308-1232, IGR J1509-6649, IGR J17195-4100, and RX J0636+3535 display a disc-overflow accretion mode. All sources show a temperature gradient in the post-shock regions and a highly absorbed emission from material located in the pre-shock flow which is also responsible for the X-ray pulsations. Reflection at the WD surface is likely the origin of the fluorescent iron line. There is an increasing evidence for the presence of a warm absorber in IPs, a feature that needs future exploration. The addition of two systems to the subgroup of

  14. Radiation dose rate affects the radiosensitization of MCF-7 and HeLa cell lines to X-rays induced by dextran-coated iron oxide nanoparticles.

    Science.gov (United States)

    Khoshgard, Karim; Kiani, Parvaneh; Haghparast, Abbas; Hosseinzadeh, Leila; Eivazi, Mohammad Taghi

    2017-08-01

    The aim of radiotherapy is to deliver lethal damage to cancerous tissue while preserving adjacent normal tissues. Radiation absorbed dose of the tumoral cells can increase when high atomic nanoparticles are present in them during irradiation. Also, the dose rate is an important aspect in radiation effects that determines the biological results of a given dose. This in vitro study investigated the dose-rate effect on the induced radiosensitivity by dextran-coated iron oxide in cancer cells. HeLa and MCF-7 cells were cultured in vitro and incubated with different concentrations of dextran-coated iron oxide nanoparticles. They were then irradiated with 6 MV photons at dose rates of 43, 185 and 370 cGy/min. The MTT test was used to obtain the cells' survival after 48 h of irradiations. Incubating the cells with the nanoparticles at concentrations of 10, 40 and 80 μg/ml showed no significant cytotoxicity effect. Dextran-coated iron oxide nanoparticles showed more radiosensitivity effect by increasing the dose rate and nanoparticles concentration. Radiosensitization enhancement factors of MCF-7 and HeLa cells at a dose-rate of 370 cGy/min and nanoparticles' concentration of 80 μg/ml were 1.21 ± 0.06 and 1.19 ± 0.04, respectively. Increasing the dose rate of 6 MV photons irradiation in MCF-7 and HeLa cells increases the radiosensitization induced by the dextran-coated iron nanoparticles in these cells.

  15. Large aperture Fizeau interferometer commissioning and preliminary measurements of a long x-ray mirror at European X-ray Free Electron Laser

    Science.gov (United States)

    Vannoni, M.; Freijo Martín, I.

    2016-05-01

    The European XFEL (X-ray Free Electron Laser) is a large facility under construction in Hamburg, Germany. It will provide a transversally fully coherent x-ray radiation with outstanding characteristics: high repetition rate (up to 2700 pulses with a 0.6 ms long pulse train at 10 Hz), short wavelength (down to 0.05 nm), short pulse (in the femtoseconds scale), and high average brilliance (1.6 ṡ 1025 (photons s-1 mm-2 mrad-2)/0.1% bandwidth). The beam has very high pulse energy; therefore, it has to be spread out on a relatively long mirror (about 1 m). Due to the very short wavelength, the mirrors need to have a high quality surface on their entire length, and this is considered very challenging even with the most advanced polishing methods. In order to measure the mirrors and to characterize their interaction with the mechanical mount, we equipped a metrology laboratory with a large aperture Fizeau interferometer. The system is a classical 100 mm diameter commercial Fizeau, with an additional expander providing a 300 mm diameter beam. Despite the commercial nature of the system, special care has been taken in the polishing of the reference flats and in the expander quality. We report the first commissioning of the instrument, its calibration, and performance characterization, together with some preliminary results with the measurement of a 950 mm silicon substrate. The intended application is to characterize the final XFEL mirrors with nanometer accuracy.

  16. Large aperture Fizeau interferometer commissioning and preliminary measurements of a long x-ray mirror at European X-ray Free Electron Laser.

    Science.gov (United States)

    Vannoni, M; Freijo Martín, I

    2016-05-01

    The European XFEL (X-ray Free Electron Laser) is a large facility under construction in Hamburg, Germany. It will provide a transversally fully coherent x-ray radiation with outstanding characteristics: high repetition rate (up to 2700 pulses with a 0.6 ms long pulse train at 10 Hz), short wavelength (down to 0.05 nm), short pulse (in the femtoseconds scale), and high average brilliance (1.6 ⋅ 10(25) (photons s(-1) mm(-2) mrad(-2))/0.1% bandwidth). The beam has very high pulse energy; therefore, it has to be spread out on a relatively long mirror (about 1 m). Due to the very short wavelength, the mirrors need to have a high quality surface on their entire length, and this is considered very challenging even with the most advanced polishing methods. In order to measure the mirrors and to characterize their interaction with the mechanical mount, we equipped a metrology laboratory with a large aperture Fizeau interferometer. The system is a classical 100 mm diameter commercial Fizeau, with an additional expander providing a 300 mm diameter beam. Despite the commercial nature of the system, special care has been taken in the polishing of the reference flats and in the expander quality. We report the first commissioning of the instrument, its calibration, and performance characterization, together with some preliminary results with the measurement of a 950 mm silicon substrate. The intended application is to characterize the final XFEL mirrors with nanometer accuracy.

  17. X-ray data booklet. Revision

    Energy Technology Data Exchange (ETDEWEB)

    Vaughan, D. (ed.)

    1986-04-01

    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)

  18. X-ray generation using carbon nanotubes

    OpenAIRE

    Parmee, Richard J.; Collins, Clare M.; William I. Milne; Cole, Matthew T.

    2015-01-01

    This is the final published version. It first appeared at http://www.nanoconvergencejournal.com/content/2/1/1. Since the discovery of X-rays over a century ago the techniques applied to the engineering of X-ray sources have remained relatively unchanged. From the inception of thermionic electron sources, which, due to simplicity of fabrication, remain central to almost all X-ray applications, there have been few fundamental technological advances. However, with the emergence of ever more d...

  19. Applications of soft x-ray lasers

    Energy Technology Data Exchange (ETDEWEB)

    Skinner, C.H.

    1993-08-01

    The high brightness and short pulse duration of soft x-ray lasers provide unique advantages for novel applications. Imaging of biological specimens using x-ray lasers has been demonstrated by several groups. Other applications to fields such as chemistry, material science, plasma diagnostics, and lithography are beginning to emerge. We review the current status of soft x-ray lasers from the perspective of applications, and present an overview of the applications currently being developed.

  20. Topological X-Rays and MRIs

    Science.gov (United States)

    Lynch, Mark

    2002-01-01

    Let K be a compact subset of the interior of the unit disk D in the plane and suppose one can't see through the boundary of D and identify K. However, assume that one can take "topological X-rays" of D which measure the "density" of K along the lines of the X-rays. By taking these X-rays from all directions, a "topological MRI" is generated for…

  1. Frequency and amplitude characteristics of a high-repetition-rate hybrid TEA-CO/sub 2/ laser

    Energy Technology Data Exchange (ETDEWEB)

    Lachambre, J.L.; Lavigne, P.; Verreault, M.; Otis, G.

    1978-02-01

    The envelope and frequency characteristics of the output pulse of a high-repetition-rate hybrid TEA-CO/sub 2/ laser are presented. Both the intrapulse and interpulse laser frequency stability are experimentally determined at repetition rates up to 300 Hz. The recovery of the CW laser signal following the generation of the TEA laser pulse is analyzed theoretically and experimentally. Short term reproducibilities of + or - 2 MHz are observed at a pulse repetition rate of 300 Hz with initial chirp rates of about 1.5 MHz/microsec. Improvements and limits on power and repetition rate are discussed.

  2. Observation of femtosecond X-ray interactions with matter using an X-ray-X-ray pump-probe scheme.

    Science.gov (United States)

    Inoue, Ichiro; Inubushi, Yuichi; Sato, Takahiro; Tono, Kensuke; Katayama, Tetsuo; Kameshima, Takashi; Ogawa, Kanade; Togashi, Tadashi; Owada, Shigeki; Amemiya, Yoshiyuki; Tanaka, Takashi; Hara, Toru; Yabashi, Makina

    2016-02-01

    Resolution in the X-ray structure determination of noncrystalline samples has been limited to several tens of nanometers, because deep X-ray irradiation required for enhanced resolution causes radiation damage to samples. However, theoretical studies predict that the femtosecond (fs) durations of X-ray free-electron laser (XFEL) pulses make it possible to record scattering signals before the initiation of X-ray damage processes; thus, an ultraintense X-ray beam can be used beyond the conventional limit of radiation dose. Here, we verify this scenario by directly observing femtosecond X-ray damage processes in diamond irradiated with extraordinarily intense (∼10(19) W/cm(2)) XFEL pulses. An X-ray pump-probe diffraction scheme was developed in this study; tightly focused double-5-fs XFEL pulses with time separations ranging from sub-fs to 80 fs were used to excite (i.e., pump) the diamond and characterize (i.e., probe) the temporal changes of the crystalline structures through Bragg reflection. It was found that the pump and probe diffraction intensities remain almost constant for shorter time separations of the double pulse, whereas the probe diffraction intensities decreased after 20 fs following pump pulse irradiation due to the X-ray-induced atomic displacement. This result indicates that sub-10-fs XFEL pulses enable conductions of damageless structural determinations and supports the validity of the theoretical predictions of ultraintense X-ray-matter interactions. The X-ray pump-probe scheme demonstrated here would be effective for understanding ultraintense X-ray-matter interactions, which will greatly stimulate advanced XFEL applications, such as atomic structure determination of a single molecule and generation of exotic matters with high energy densities.

  3. Phase-contrast X-ray CT

    Energy Technology Data Exchange (ETDEWEB)

    Momose, Atsushi [Hitachi Ltd., Saitama (Japan). Advanced Research Laboratory; Takeda, Tohoru; Itai, Yuji

    1995-12-01

    Phase-contrast X-ray computed tomography (CT) enabling the observation of biological soft tissues without contrast enhancement has been developed. The X-ray phase shift caused by an object is measured and input to a standard CT reconstruction algorithm. A thousand times increase in the image sensitivity to soft tissues is achieved compared with the conventional CT using absorption contrast. This is because the X-ray phase shift cross section of light elements is about a thousand times larger than the absorption cross section. The phase shift is detected using an X-ray interferometer and computer analyses of interference patterns. Experiments were performed using a synchrotron X-ray source. Excellent image sensitivity is demonstrated in the observation of cancerous rabbit liver. The CT images distinguish cancer lesion from normal liver tissue and, moreover, visualize the pathological condition in the lesion. Although the X-ray energy employed and the present observation area size are not suitable for medical applications as they are, phase-contrast X-ray CT is promising for investigating the internal structure of soft tissue which is almost transparent for X-rays. The high sensitivity also provides the advantage of reducing X-ray doses. (author).

  4. An Imaging X-Ray Polarimetry Mission

    Science.gov (United States)

    Weisskopf, Martin C.; Bellazini, Ronaldo; Costa, Enrico; Ramsey, Brian; O'Dell, Steve; Elsner, Ronald; Pavlov, George; Matt, Giorgio; Kaspi, Victoria; Tennant, Allyn; Coppi, Paolo; Wu, Kinwah; Siegmund, Oswald

    2008-01-01

    Technical progress both in x-ray optics and in polarization-sensitive x-ray detectors, which our groups have pioneered, enables a scientifically powerful---yet inexpensive---dedicated mission for imaging x-ray polarimetry. Such a mission is sufficiently sensitive to measure x-ray (linear) polarization for a broad range of cosmic sources --particularly those involving neutron stars, stellar black holes, and supermassive black holes (active galactic nuclei). We describe the technical elements, discuss a mission concept, and synopsize the important physical and astrophysical questions such a mission would address.

  5. The efficacy of x-ray pelvimetry

    Energy Technology Data Exchange (ETDEWEB)

    Barton, J.J. (Univ. of Illinois, Chicago); Garbaciak, J.A. Jr.; Ryan, G.M., Jr.

    1982-06-01

    Comparison is made of x-ray pelvimetry use on a public and private service in 1974 with experience in 1979, when the clinic service did no x-ray pelvimetry while the private service continued as before. It is concluded that the use of x-ray pelvimetry is inadequate as a predictor of cesarean section because of cephalopelvic disproportion, does not improve neonatal mortality, and poses potential hazards to the mother and fetus. Its use in the management of breech presentations is not currently established by our data. Guidelines are presented for the management of patients in labor without using x-ray pelvimetry.

  6. Ultrashort X-ray pulse science

    Energy Technology Data Exchange (ETDEWEB)

    Chin, Alan Hap [Univ. of California, Berkeley, CA (US). Dept. of Physics; Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    1998-05-01

    A variety of phenomena involves atomic motion on the femtosecond time-scale. These phenomena have been studied using ultrashort optical pulses, which indirectly probe atomic positions through changes in optical properties. Because x-rays can more directly probe atomic positions, ultrashort x-ray pulses are better suited for the study of ultrafast structural dynamics. One approach towards generating ultrashort x-ray pulses is by 90° Thomson scattering between terawatt laser pulses and relativistic electrons. Using this technique, the author generated ~ 300 fs, 30 keV (0.4 Å) x-ray pulses. These x-ray pulses are absolutely synchronized with ultrashort laser pulses, allowing femtosecond optical pump/x-ray probe experiments to be performed. Using the right-angle Thomson scattering x-ray source, the author performed time-resolved x-ray diffraction studies of laser-perturbated InSb. These experiments revealed a delayed onset of lattice expansion. This delay is due to the energy relaxation from a dense electron-hole plasma to the lattice. The dense electron-hole plasma first undergoes Auger recombination, which reduces the carrier concentration while maintaining energy content. Longitudinal-optic (LO) phonon emission then couples energy to the lattice. LO phonon decay into acoustic phonons, and acoustic phonon propagation then causes the growth of a thermally expanded layer. Source characterization is instrumental in utilizing ultrashort x-ray pulses in time-resolved x-ray spectroscopies. By measurement of the electron beam diameter at the generation point, the pulse duration of the Thomson scattered x-rays is determined. Analysis of the Thomson scattered x-ray beam properties also provides a novel means of electron bunch characterization. Although the pulse duration is inferred for the Thomson scattering x-ray source, direct measurement is required for other x-ray pulse sources. A method based on the laser-assisted photoelectric effect (LAPE) has been demonstrated as a

  7. Hard X-ray Modulation Telescope

    Institute of Scientific and Technical Information of China (English)

    LU Fangjun

    2011-01-01

    The Hard X-ray Modulation Telescope (HXMT) will be China's first astronomical satellite. On board HXMT there are three kinds of slat-collimated telescopes, the High Energy X-ray Telescope (HE, 20-250 keV, 5000 cm^2), the Medium Energy X-ray Telescope (ME, 5-30 keV, 952 cm^2), and the Low Energy X-ray Telescope (LE, 1-15 keV, 384 cm^2).

  8. Ultrashort X-ray pulse science

    Energy Technology Data Exchange (ETDEWEB)

    Chin, Alan Hap [Univ. of California, Berkeley, CA (US). Dept. of Physics; Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    1998-05-01

    A variety of phenomena involves atomic motion on the femtosecond time-scale. These phenomena have been studied using ultrashort optical pulses, which indirectly probe atomic positions through changes in optical properties. Because x-rays can more directly probe atomic positions, ultrashort x-ray pulses are better suited for the study of ultrafast structural dynamics. One approach towards generating ultrashort x-ray pulses is by 90{sup o} Thomson scattering between terawatt laser pulses and relativistic electrons. Using this technique, the author generated {approx} 300 fs, 30 keV (0.4 {angstrom}) x-ray pulses. These x-ray pulses are absolutely synchronized with ultrashort laser pulses, allowing femtosecond optical pump/x-ray probe experiments to be performed. Using the right-angle Thomson scattering x-ray source, the author performed time-resolved x-ray diffraction studies of laser-perturbated InSb. These experiments revealed a delayed onset of lattice expansion. This delay is due to the energy relaxation from a dense electron-hole plasma to the lattice. The dense electron-hole plasma first undergoes Auger recombination, which reduces the carrier concentration while maintaining energy content. Longitudinal-optic (LO) phonon emission then couples energy to the lattice. LO phonon decay into acoustic phonons, and acoustic phonon propagation then causes the growth of a thermally expanded layer. Source characterization is instrumental in utilizing ultrashort x-ray pulses in time-resolved x-ray spectroscopies. By measurement of the electron beam diameter at the generation point, the pulse duration of the Thomson scattered x-rays is determined. Analysis of the Thomson scattered x-ray beam properties also provides a novel means of electron bunch characterization. Although the pulse duration is inferred for the Thomson scattering x-ray source, direct measurement is required for other x-ray pulse sources. A method based on the laser-assisted photoelectric effect (LAPE) has

  9. An Imaging X-Ray Polarimetry Mission

    Science.gov (United States)

    Weisskopf, Martin C.; Bellazini, Ronaldo; Costa, Enrico; Ramsey, Brian; O'Dell, Steve; Elsner, Ronald; Pavlov, George; Matt, Giorgio; Kaspi, Victoria; Tennant, Allyn; hide

    2008-01-01

    Technical progress both in x-ray optics and in polarization-sensitive x-ray detectors, which our groups have pioneered, enables a scientifically powerful---yet inexpensive---dedicated mission for imaging x-ray polarimetry. Such a mission is sufficiently sensitive to measure x-ray (linear) polarization for a broad range of cosmic sources --particularly those involving neutron stars, stellar black holes, and supermassive black holes (active galactic nuclei). We describe the technical elements, discuss a mission concept, and synopsize the important physical and astrophysical questions such a mission would address.

  10. X-rays from the youngest stars

    Science.gov (United States)

    Feigelson, Eric D.

    1994-01-01

    The X-ray properties of classical and weak-lined T Tauri stars are briefly reviewed, emphasizing recent results from the ROSAT satellite and prospects for ASCA. The interpretation of the high level of T Tauri X-rays as enhanced solar-type magnetic activity is discussed and criticized. The census of X-ray emitters is significantly increasing estimates of galactic star formation efficiency, and X-ray emission may be important for self-regulation of star formation. ASCA images will detect star formation regions out to several kiloparsecs and will study the magnetically heated plasma around T Tauri stars. However, images will often suffer from crowding effects.

  11. X-ray emission from comets.

    Science.gov (United States)

    Cravens, T E

    2002-05-10

    The discovery of x-ray emission from comet Hyakutake was surprising given that comets are known to be cold. Observations by x-ray satellites such as the Röntgen Satellite (ROSAT) indicate that x-rays are produced by almost all comets. Theoretical and observational work has demonstrated that charge-exchange collisions of highly charged solar wind ions with cometary neutral species can explain this emission. X-ray observations of comets and other solar system objects may be used to determine the structure and dynamics of the solar wind.

  12. X-ray pulsar rush in 1998

    Energy Technology Data Exchange (ETDEWEB)

    Imanishi, K.; Tsujimoto, K.; Nishiuchi, Mamiko; Yokogawa, J.; Koyama, K. [Kyoto Univ., Faculty of Science, Kyoto (Japan)

    1999-08-01

    We present recent remarkable topics about discoveries of X-ray pulsars. 1. Pulsations from two Soft Gamma-ray Repeaters: These pulsars have enormously strong magnetic field (B {approx} 10{sup 15} G), thus these are called as 'magnetar', new type of X-ray pulsars. 2. New Crab-like pulsars: These discoveries lead to suggesting universality of Crab-like pulsars. 3. An X-ray bursting millisecond pulsar: This is strong evidence for the recycle theory of generating radio millisecond pulsars. 4. X-ray pulsar rush in the SMC: This indicates the younger star formation history in the SMC. (author)

  13. X-Ray Scan Detection for Cargo Integrity

    Energy Technology Data Exchange (ETDEWEB)

    Valencia, Juan D.; Miller, Steven D.

    2011-04-18

    ABSTRACT The increase of terrorism and its global impact has made the determination of the contents of cargo containers a necessity. Existing technology allows non-intrusive inspections to determine the contents of a container rapidly and accurately. However, some cargo shipments are exempt from such inspections. Hence, there is a need for a technology that enables rapid and accurate means of detecting whether such containers were non-intrusively inspected. Non-intrusive inspections are most commonly performed utilizing high powered X-ray equipment. The challenge is creating a device that can detect short duration X-ray scans while maintaining a portable, battery powered, low cost, and easy to use platform. The Pacific Northwest National Laboratory (PNNL) has developed a methodology and prototype device focused on this challenge. The prototype, developed by PNNL, is a battery powered electronic device that continuously measures its X-ray and Gamma exposure, calculates the dose equivalent rate, and makes a determination of whether the device has been exposed to the amount of radiation experienced during an X-ray inspection. Once an inspection is detected, the device will record a timestamp of the event and relay the information to authorized personnel via a visual alert, USB connection, and/or wireless communication. The results of this research demonstrate that PNNL’s prototype device can be effective at determining whether a container was scanned by X-ray equipment typically used for cargo container inspections. This paper focuses on laboratory measurements and test results acquired with the PNNL prototype device using several X-ray radiation levels. Keywords: Radiation, Scan, X-ray, Gamma, Detection, Cargo, Container, Wireless, RF

  14. Correlated X-ray/Ultraviolet/Optical Variability in NGC 6814

    CERN Document Server

    Troyer, Jon; Cackett, Edward; Bentz, Misty; Goad, Michael; Horne, Keith; Seals, James

    2015-01-01

    We present results of a 3-month combined X-ray/UV/optical monitoring campaign of the Seyfert 1 galaxy NGC 6814. The object was monitored by Swift from June through August 2012 in the X-ray and UV bands and by the Liverpool Telescope from May through July 2012 in B and V. The light curves are variable and significantly correlated between wavebands. Using cross-correlation analysis, we compute the time lag between the X-ray and lower energy bands. These lags are thought to be associated with the light travel time between the central X-ray emitting region and areas further out on the accretion disc. The computed lags support a thermal reprocessing scenario in which X-ray photons heat the disc and are reprocessed into lower energy photons. Additionally, we fit the lightcurves using CREAM, a Markov Chain Monte Carlo code for a standard disc. The best-fitting standard disc model yields unreasonably high super-Eddington accretion rates. Assuming more reasonable accretion rates would result in significantly under-pre...

  15. Prospects for laser spectroscopy of highly charged ions with high-harmonic XUV and soft x-ray sources

    OpenAIRE

    Rothhardt, J.; Hädrich, S.; Demmler, S.; Krebs, M.; Winters, Danyal; Kühl, Thomas; Stöhlker, Thomas; Limpert, J.; Tünnermann, A.

    2015-01-01

    We present novel high photon flux XUV and soft x-ray sources based on high harmonic generation (HHG). The sources employ femtosecond fiber lasers, which can be operated at very high (MHz) repetition rate and average power (>100 W). HHG with such lasers results in similar to 10(13) photons s(-1) within a single harmonic line at similar to 40 nm (similar to 30 eV) wavelength, a photon flux comparable to what is typically available at synchrotron beam lines. In addition, resonant enhancement of ...

  16. Avalanche Photodiodes as Fast X-ray Detectors.

    Science.gov (United States)

    Kishimoto, S

    1998-05-01

    An avalanche photodiode (APD) detector provides a sub-nanosecond time resolution and an output rate of more than 10(8) counts s(-1) of synchrotron X-rays. Moreover, the APD has the advantage of low noise. A review of recent developments of detectors using APD devices designed for X-ray experiments is presented in this paper. One of the detectors has an excellent time response of 100 ps resolution and a narrow width on its response function, 1.4 ns at 10(-5) maximum. The other consists of a stack of four diodes and has a transmission structure. The stacked detector improved the efficiency for X-rays, e.g. 55% at 16.53 keV. The output rates reached more than 10(8) counts s(-1) per device.

  17. Femtosecond Ti:sapphire cryogenic amplifier with high gain and MHz repetition rate

    DEFF Research Database (Denmark)

    Dantan, Aurelien Romain; Laurat, Julien; Ourjoumtsev, Alexei

    2007-01-01

    We demonstrate high gain amplification of 160-femtosecond pulses in a compact double-pass cryogenic Ti:sapphire amplifier. The setup involves a negative GVD mirrors recompression stage, and operates with a repetition rate between 0.2 and 4 MHz with a continuous pump laser. Amplification factors...

  18. Effect of the pulse repetition rate on fiber-assisted tissue ablation

    Science.gov (United States)

    Kang, Hyun Wook

    2016-07-01

    The effect of the pulse repetition rate on ablation performance was evaluated ex vivo at various fiber sweeping speeds for an effective 532-nm laser prostatectomy. Three pulse repetition rates (7.5, 15, and 30 kHz) at 100 W were delivered to bovine liver tissue at three sweeping speeds (2, 4, and 6 mm/s) to achieve bulky tissue removal. Ablation performance was quantitatively compared in terms of the ablation volume and the coagulation thickness. The lowest pulse repetition rate of 7.5 kHz attained the highest ablation volume (101.5 ± 12.0 mm3) and the thinnest coagulation (0.7 ± 0.1 mm) along with superficial carbonization. The highest pulse repetition rate of 30 kHz was associated with the least tissue removal (65.8 ± 5.0 mm3) and the deepest thermal denaturation (1.1 ± 0.2 mm). Quantitative evaluations of laser parameters can be instrumental in facilitating ablation efficiency and maintaining hemostatic coagulation during treatment of large-sized benign prostate hyperplasia.

  19. Multi-gigahertz repetition rate ultrafast waveguide lasers mode-locked with graphene saturable absorbers

    Science.gov (United States)

    Obraztsov, P. A.; Okhrimchuk, A. G.; Rybin, M. G.; Obraztsova, E. D.; Garnov, S. V.

    2016-08-01

    We report the development of an approach to build compact waveguide lasers that operate in the stable fundamental mode-locking regime with multigigahertz repetition rates. The approach is based on the use of depressed cladding multi- or single-mode waveguides fabricated directly in the active laser crystal using the femtosecond laser inscription method and a graphene saturable absorber. Using this approach we achieve the stable self-starting mode-locking operation of a diode-pumped waveguide Nd:YAG laser that delivers picosecond pulses at a repetition rate of up to 11.5 GHz with an average power of 12 mW at a central wavelength of 1064 nm. The saturable absorbers are formed through the chemical vapor deposition of single-layer graphene on the output coupler mirror or directly on the end facet of the laser crystal. The stable self-starting mode-locking operation is achieved by controlling the group delay dispersion in the laser cavity with an intracavity interferometer. The method developed for the creation of compact ultrashort pulse laser generators with gigahertz repetition rates can be extended further and applied for the development of compact high-repetition rate lasers that operate at a wide range of IR wavelengths.

  20. Operation and Thermal Modeling of the ISIS H– Source from 50 to 2 Hz Repetition Rates

    CERN Document Server

    Pereira, H; Lettry, J

    2013-01-01

    CERN’s Linac4 accelerator H− ion source, currently under construction, will operate at a 2 Hz repetition rate, with pulse length of 0.5 ms and a beam current of 80 mA. Its reliability must exceed 99 % with a mandatory 3 month uninterrupted operation period. A Penning ion source is successfully operated at ISIS; at 50 Hz repetition rate it reliably provides 55 mA H− pulses of 0.25 ms duration over 1 month. The discharge plasma ignition is very sensitive to the temperatures of the discharge region, especially of its cathode. The investigation by modeling and measurement of operation parameters suitable for arc ignition and H− production at 2 Hz is of paramount importance and must be understood prior to the implementation of discharge ion sources in the Linac4 accelerator. In its original configuration, the ISIS H− source delivers beam only if the repetition rate is above 12.5 Hz, this paper describes the implementation of a temperature control of the discharge region aiming at lower repetition rate op...

  1. High Repetition Rate and Frequency Stabilized Ho:YLF Laser for CO2 Differential Absorption Lidar

    Science.gov (United States)

    Bai, Yingxin; Yu, Jirong; Petros, M.; Petzar, Pau; Trieu, Bo; Lee, Hyung; Singh, U.

    2009-01-01

    High repetition rate operation of an injection seeded Ho:YLF laser has been demonstrated. For 1 kHz operation, the output pulse energy reaches 5.8mJ and the optical-to-optical efficiency is 39% when the pump power is 14.5W.

  2. DFB diode seeded low repetition rate fiber laser system operating in burst mode

    Science.gov (United States)

    Šajn, M.; Petelin, J.; Agrež, V.; Vidmar, M.; Petkovšek, R.

    2017-02-01

    A distributed feedback (DFB) diode, gain switched to produce pulses from 60 ps at high peak power of over 0.5 W, is used in burst mode to seed a fiber amplifier chain. High seed power, spectral filtering between amplifier stages and pulsed pumping are used to mitigate amplified spontaneous emission (ASE). The effect of pulse pumping synchronized with the seed on the ASE is explored for the power amplifier at low repetition. Different input and output energies at different burst repetition rates are examined and up to 85% reduction in ASE is achieved compared to continuous pumping. Finally, a numerical model is used to predict further reduction of ASE.

  3. Explosives detection using photoneutrons produced by X-rays

    Science.gov (United States)

    Yang, Yigang; Li, Yuanjing; Wang, Haidong; Li, Tiezhu; Wu, Bin

    2007-08-01

    The detection of explosives has become a critical issue after recent terrorist attacks. This paper describes research on explosives detection using photoneutrons from a photoneutron convertor that consists of 20 kg heavy water in an aluminum container whose shape was optimized to most effectively convert X-rays to photoneutrons. The X-rays were produced by a 9 MeV electron accelerator with an average electron current of 100 μA, resulted in a photoneutron yield of >10 11 n/s. Monte-Carlo simulations show that the radiation field is composed of X-ray pulses, fast neutron pulses and thermal neutrons. Both the X-ray and fast neutron pulses are 5 μs wide with a 300 Hz repetition frequency. The thermal neutron flux, which is higher than 10 4 n/cm 2/s, is essentially time invariant. A time shielding circuit was developed for the spectrometry system to halt the sampling process during the intense X-ray pulses. Paraffin, boron carbide and lead were used to protect the detector from interference from the X-rays, fast neutrons, thermal neutrons and background γ-rays coming from the system materials induced by photoneutrons. 5″×5″ NaI (Tl) scintillators were chosen as the detectors to detect the photoneutrons induced γ-rays from the inspected explosive simulant. Nitrogen (6.01 cps) 10.828 MeV γ-rays were detected with one detector from a 50 kg carbamide block placed 60 cm in front of the detector. A collimator was used to reduce the number of background 10.828 MeV γ-rays coming from the nitrogen in the air to improve the signal to background ratio from 0.136 to 1.81. A detector array of seven 5″×5″ NaI (Tl) detectors was used to measure the 2-D distributions of N and H in the sample. The combination of photoneutron analysis and X-ray imaging shows promise for enhancing explosives detection capabilities.

  4. Passively Mode-Locked Fiber Laser with a Sub-Megahertz Repetition Rate

    Institute of Scientific and Technical Information of China (English)

    CHEN Jiong; JIA Dong-Fang; WU Yong-Chao; WANG Chang-Le; WANG Zhao-Ying; YANG Tian-Xin

    2011-01-01

    We demonstrate an ultra-long cavity by which an all-fiber erbium-doped fiber laser is passively mode-locked by nonlinear polarization rotation.The length of the resonant cavity amounts to 466m,which can be achieved by incorporating a 420m highly nonlinear fiber.The laser generates stable mode-locked pulses with a 444 kHz fundamental repetition rate.A near transform-limited subpicosecond pulse is obtained without any dispersion compensation.The maximum average power of the output pulses is 5.16 mW,which corresponds to a per-pulse energy of 11.62nJ.A low-repetition-rate optical pulse train is required for many applications such as micromachining,biomedical diagnostics and lidar systems.[1-3] However,the repetition rate of conventional fiber lasers is normally tens of MHz.Pulse pickers such as Pockels cells or acousto-optic modulators are always used to lower the repetition rate,however,reduction in this way introduces significant energy losses,impairs the signal-to-noise ratio (SNR) and increases complexity.Because the pulse repetition rate of a modelocked laser is inversely proportional to its resonator length,longer cavities lead to lower pulse repetition rates and,consequently,to higher pulse energy at the same average power of radiation.%We demonstrate an ultra-long cavity by which an all-fiber erbium-doped fiber laser is passively mode-locked by nonlinear polarization rotation. The length of the resonant cavity amounts to 466 m, which can be achieved by incorporating a 420 m highly nonlinear fiber. The laser generates stable mode-locked pulses with a 444 kHz fundamental repetition rate. A near transform-limited subpicosecond pulse is obtained without any dispersion compensation. The maximum average power of the output pulses is 5.16mW, which corresponds to a per-pulse energy of 11.62 nJ.

  5. Muonic X-ray spectroscopy: Effect of the presence of protons on X-ray production

    National Research Council Canada - National Science Library

    Mohamadsalehi, F; Gheisari, R; Rahimi, N

    2016-01-01

    ... . The target has a high efficiency for analyzing characteristic X-rays in ion implantation. To predict the effect of the presence of protons on X-ray production, we have proposed a new kinetic schema...

  6. SMM X-ray polychromator

    Science.gov (United States)

    Strong, Keith T.; Haisch, Bernhard M. (Compiler); Lemen, James R. (Compiler); Acton, L. W.; Bawa, H. S.; Claflin, E. S.; Freeland, S. L.; Slater, G. L.; Kemp, D. L.; Linford, G. A.

    1988-01-01

    The range of observing and analysis programs accomplished with the X-Ray Polychromator (XRP) instruments during the decline of solar cycle 21 and the rise of the solar cycle 22 is summarized. Section 2 describes XRP operations and current status. This is meant as a guide on how the instrument is used to obtain data and what its capabilities are for potential users. The science section contains a series of representative abstracts from recently published papers on major XRP science topics. It is not meant to be a complete list but illustrates the type of science that can come from the analysis of the XRP data. There then follows a series of appendixes that summarize the major data bases that are available. Appendix A is a complete bibliography of papers and presentations produced using XRP data. Appendix B lists all the spectroscopic data accumulated by the Flat Crystal Spectrometer (FCS). Appendix C is a compilation of the XRP flare catalogue for events equivalent to a GOES C-level flare or greater. It lists the start, peak and end times as well as the peak Ca XIX flux.

  7. Analyzing the Spectra of Accreting X-Ray Pulsars

    Science.gov (United States)

    Wolff, Michael

    This proposal seeks funding for the analysis of accretion-powered X-ray pulsar spectra from NASA/ HEASARC archived X-ray data. Spectral modeling of accreting X-ray pulsars can tell us a great deal about the physical conditions in and near high mass X-ray binary systems. Such systems have accretion flows where plasma is initially channeled from an accretion disk by the strong neutron star magnetic field, eventually falling onto the magnetic polar cap of the neutron star compact object. Many of these accreting X-ray pulsars have X-ray spectra that consist of broad power-law continua with superposed cyclotron resonant scattering features indicating magnetic field strengths above 10^12 G. The energies of these cyclotron line features have recently been shown to vary with X-ray luminosity in a number of sources such as Her X-1 and V 0332+53, a phenomenon not well understood. Another recent development is the relatively new analytic model for the spectral continuum formation in accretion-powered pulsar systems developed by Becker & Wolff. In their formalism the accretion flows are assumed to go through radiation- dominated radiative shocks and settle onto the neutron star surface. The radiation field consists of strongly Comptonized bremsstrahlung emission from the entire plasma, Comptonized cyclotron emission from the de-excitations of Landau-excited electrons in the neutron star magnetic field, and Comptonized black-body emission from a thermal mound near the neutron star surface. We seek to develop the data analysis tools to apply this model framework to the X-ray data from a wide set of sources to make progress characterizing the basic accretion properties (e.g., magnetic field strength, plasma temperatures, polar cap size, accretion rate per unit area, dominance of bulk vs. thermal Comptonization) as well as understanding the variations of the cyclotron line energies with X-ray luminosity. The three major goals of our proposed work are as follows: In the first year

  8. L X-ray emission induced by heavy ions

    Energy Technology Data Exchange (ETDEWEB)

    Pajek, M. [Institute of Physics, Jan Kochanowski University, 25-406 Kielce (Poland); Banaś, D., E-mail: d.banas@ujk.edu.pl [Institute of Physics, Jan Kochanowski University, 25-406 Kielce (Poland); Braziewicz, J.; Majewska, U.; Semaniak, J. [Institute of Physics, Jan Kochanowski University, 25-406 Kielce (Poland); Fijał-Kirejczyk, I. [The Institute of Atomic Energy, 05-400 Otwock-Świerk (Poland); Jaskóła, M.; Czarnacki, W.; Korman, A. [The National Centre for Nuclear Research, 05-400 Otwock-Świerk (Poland); Kretschmer, W. [Physikalisches Institut, Universität Erlangen-Nürnberg, D-91058 Erlangen (Germany); Mukoyama, T. [Institute for Nuclear Research, Hungarian Academy of Sciences (ATOMKI), H-4026 Debrecen (Hungary); Trautmann, D. [Institut für Physik, Universität Basel, Basel (Switzerland)

    2015-11-15

    Particle-induced X-ray emission (PIXE) technique is usually applied using typically 1 MeV to 3 MeV protons or helium ions, for which the ion-atom interaction is dominated by the single ionization process. For heavier ions the multiple ionization plays an increasingly important role and this process can influence substantially both the X-ray spectra and atomic decay rates. Additionally, the subshell coupling effects are important for the L- and M-shells ionized by heavy ions. Here we discuss the main features of the X-ray emission induced by heavy ions which are important for PIXE applications, namely, the effects of X-ray line shifts and broadening, vacancy rearrangement and change of the fluorescence and Coster–Kronig yields in multiple ionized atoms. These effects are illustrated here by the results of the measurements of L X-ray emission from heavy atoms bombarded by 6 MeV to 36 MeV Si ions, which were reported earlier. The strong L-subshell coupling effects are observed, in particular L{sub 2}-subshell, which can be accounted for within the coupling subshell model (CSM) developed within the semiclassical approximation. Finally, the prospects to use heavy ions in PIXE analysis are discussed.

  9. X-ray Counterparts of Millisecond Pulsars in Globular Clusters

    CERN Document Server

    Becker, W; Prinz, T

    2010-01-01

    We have systematically studied the X-ray emission properties of globular cluster millisecond pulsars in order to evaluate their spectral properties and luminosities in a uniform way. Cross-correlating the radio timing positions of the cluster pulsars with the high resolution Chandra images revealed 31 X-ray counterparts identified in nine different globular cluster systems, including those in 47 Tuc. Timing analysis has been performed for all sources corresponding to the temporal resolution available in the archival Chandra data. Making use of unpublished data on M28, M4 and NGC 6752 allowed us to obtain further constraints for the millisecond pulsar counterparts located in these clusters. Counting rate and energy flux upper limits were computed for those 36 pulsars for which no X-ray counterparts could be detected. Comparing the X-ray and radio pulse profiles of PSR J1821-2452 in M28 and the 47 Tuc pulsars PSR J0024-7204D,O,R indicated some correspondence between both wavebands. The X-ray efficiency of the g...

  10. L X-ray emission induced by heavy ions

    Science.gov (United States)

    Pajek, M.; Banaś, D.; Braziewicz, J.; Majewska, U.; Semaniak, J.; Fijał-Kirejczyk, I.; Jaskóła, M.; Czarnacki, W.; Korman, A.; Kretschmer, W.; Mukoyama, T.; Trautmann, D.

    2015-11-01

    Particle-induced X-ray emission (PIXE) technique is usually applied using typically 1 MeV to 3 MeV protons or helium ions, for which the ion-atom interaction is dominated by the single ionization process. For heavier ions the multiple ionization plays an increasingly important role and this process can influence substantially both the X-ray spectra and atomic decay rates. Additionally, the subshell coupling effects are important for the L- and M-shells ionized by heavy ions. Here we discuss the main features of the X-ray emission induced by heavy ions which are important for PIXE applications, namely, the effects of X-ray line shifts and broadening, vacancy rearrangement and change of the fluorescence and Coster-Kronig yields in multiple ionized atoms. These effects are illustrated here by the results of the measurements of L X-ray emission from heavy atoms bombarded by 6 MeV to 36 MeV Si ions, which were reported earlier. The strong L-subshell coupling effects are observed, in particular L2-subshell, which can be accounted for within the coupling subshell model (CSM) developed within the semiclassical approximation. Finally, the prospects to use heavy ions in PIXE analysis are discussed.

  11. Jets and Accretion Disks in X-ray Binaries

    Science.gov (United States)

    Tomsick, John

    The outflow of material in the form of jets is a common phenomenon in astronomical sources with accretion disks. Even though jets are seen coming from the cores of galaxies, Galactic compact objects in X-ray binaries, and stars as they are forming, we do not understand in detail what accretion disk conditions are necessary to support a relativistic jet. This proposal focuses on multi-wavelength studies of X-ray binaries in order to improve our understanding of the connection between the disk and the jet. Specifically, this proposal includes work on two approved cycle 14 Rossi X-ray Timing Explorer (RXTE) programs, an approved XMM-Newton program, as well as a synthesis study of transient black hole X-ray binaries using archival RXTE and radio data. We plan to use X-ray spectral and timing properties to determine the disk properties during the re-activation of the compact jet (as seen in the radio and infrared) during the decays of black hole transient outbursts, to determine how the inner disk properties change at low mass accretion rates, and to use RXTE along with multi-wavelength observations to constrain the jet properties required for the microquasar Cygnus~X-3 to produce high- energy emission. Due to the ubiquity of jets in astrophysical settings, these science topics are relevant to NASA programs dealing with the origin, structure, evolution, and destiny of the Universe, and especially to understanding phenomena near black holes.

  12. X-Ray Probes of Cosmic Star Formation History

    Science.gov (United States)

    Ghosh, Pranab; White, Nicholas E.

    2001-01-01

    We discuss the imprints left by a cosmological evolution of the star formation rate (SFR) on the evolution of X-ray luminosities Lx of normal galaxies, using the scheme earlier proposed by us, wherein the evolution of LX of a galaxy is driven by the evolution of its X-ray binary population. As indicated in our earlier work, the profile of Lx with redshift can both serve as a diagnostic probe of the SFR profile and constrain evolutionary models for X-ray binaries. We report here the first calculation of the expected evolution of X-ray luminosities of galaxies, updating our work by using a suite of more recently developed SFR profiles that span the currently plausible range. The first Chandra deep imaging results on Lx evolution are beginning to probe the SFR profile of bright spiral galaxies; the early results are consistent with predictions based on current SFR models. Using these new SFR profiles, the resolution of the "birthrate problem" of low-mass X-ray binaries and recycled, millisecond pulsars in terms of an evolving global SFR is more complete. We discuss the possible impact of the variations in the SFR profile of individual galaxies and galaxy types.

  13. Effect of Repetition Rate on Femtosecond Laser-Induced Homogenous Microstructures

    Directory of Open Access Journals (Sweden)

    Sanchari Biswas

    2016-12-01

    Full Text Available We report on the effect of repetition rate on the formation and surface texture of the laser induced homogenous microstructures. Different microstructures were micromachined on copper (Cu and titanium (Ti using femtosecond pulses at 1 and 10 kHz. We studied the effect of the repetition rate on structure formation by comparing the threshold accumulated pulse ( F Σ p u l s e values and the effect on the surface texture through lacunarity analysis. Machining both metals at low F Σ p u l s e resulted in microstructures with higher lacunarity at 10 kHz compared to 1 kHz. On increasing F Σ p u l s e , the microstructures showed higher lacunarity at 1 kHz. The effect of the repetition rate on the threshold F Σ p u l s e values were, however, considerably different on the two metals. With an increase in repetition rate, we observed a decrease in the threshold F Σ p u l s e on Cu, while on Ti we observed an increase. These differences were successfully allied to the respective material characteristics and the resulting melt dynamics. While machining Ti at 10 kHz, the melt layer induced by one laser pulse persists until the next pulse arrives, acting as a dielectric for the subsequent pulse, thereby increasing F Σ p u l s e . However, on Cu, the melt layer quickly resolidifies and no such dielectric like phase is observed. Our study contributes to the current knowledge on the effect of the repetition rate as an irradiation parameter.

  14. Effect of Repetition Rate on Femtosecond Laser-Induced Homogenous Microstructures.

    Science.gov (United States)

    Biswas, Sanchari; Karthikeyan, Adya; Kietzig, Anne-Marie

    2016-12-19

    We report on the effect of repetition rate on the formation and surface texture of the laser induced homogenous microstructures. Different microstructures were micromachined on copper (Cu) and titanium (Ti) using femtosecond pulses at 1 and 10 kHz. We studied the effect of the repetition rate on structure formation by comparing the threshold accumulated pulse ( F Σ p u l s e ) values and the effect on the surface texture through lacunarity analysis. Machining both metals at low F Σ p u l s e resulted in microstructures with higher lacunarity at 10 kHz compared to 1 kHz. On increasing F Σ p u l s e , the microstructures showed higher lacunarity at 1 kHz. The effect of the repetition rate on the threshold F Σ p u l s e values were, however, considerably different on the two metals. With an increase in repetition rate, we observed a decrease in the threshold F Σ p u l s e on Cu, while on Ti we observed an increase. These differences were successfully allied to the respective material characteristics and the resulting melt dynamics. While machining Ti at 10 kHz, the melt layer induced by one laser pulse persists until the next pulse arrives, acting as a dielectric for the subsequent pulse, thereby increasing F Σ p u l s e . However, on Cu, the melt layer quickly resolidifies and no such dielectric like phase is observed. Our study contributes to the current knowledge on the effect of the repetition rate as an irradiation parameter.

  15. Longitudinally excited CO2 laser with short laser pulse operating at high repetition rate

    Science.gov (United States)

    Li, Jianhui; Uno, Kazuyuki; Akitsu, Tetsuya; Jitsuno, Takahisa

    2016-11-01

    A short-pulse longitudinally excited CO2 laser operating at a high repetition rate was developed. The discharge tube was made of a 45 cm-long or 60 cm-long dielectric tube with an inner diameter of 16 mm and two metallic electrodes at the ends of the tube. The optical cavity was formed by a ZnSe output coupler with a reflectivity of 85% and a high-reflection mirror. Mixed gas (CO2:N2:He = 1:1:2) was flowed into the discharge tube. A high voltage of about 33 kV with a rise time of about 200 ns was applied to the discharge tube. At a repetition rate of 300 Hz and a gas pressure of 3.4 kPa, the 45 cm-long discharge tube produced a short laser pulse with a laser pulse energy of 17.5 mJ, a spike pulse energy of 0.2 mJ, a spike width of 153 ns, and a pulse tail length of 90 μs. The output power was 5.3 W. The laser pulse waveform did not depend on the repetition rate, but the laser beam profile did. At a low repetition rate of less than 50 Hz, the laser beam had a doughnut-like shape. However, at a high repetition rate of more than 150 Hz, the discharge concentrated at the center of the discharge tube, and the intensity at the center of the laser beam was higher. The laser beam profile depended on the distribution of the discharge. An output power of 7.0 W was achieved by using the 60 cm-long tube.

  16. Diffraction leveraged modulation of X-ray pulses using MEMS-based X-ray optics

    Science.gov (United States)

    Lopez, Daniel; Shenoy, Gopal; Wang, Jin; Walko, Donald A.; Jung, Il-Woong; Mukhopadhyay, Deepkishore

    2016-08-09

    A method and apparatus are provided for implementing Bragg-diffraction leveraged modulation of X-ray pulses using MicroElectroMechanical systems (MEMS) based diffractive optics. An oscillating crystalline MEMS device generates a controllable time-window for diffraction of the incident X-ray radiation. The Bragg-diffraction leveraged modulation of X-ray pulses includes isolating a particular pulse, spatially separating individual pulses, and spreading a single pulse from an X-ray pulse-train.

  17. Relativistic electron beams driven by single-cycle laser pulses at kHz repetition rate (Conference Presentation)

    Science.gov (United States)

    Faure, Jérôme; Guénot, Diego; Gustas, Dominykas; Vernier, Aline; Beaurepaire, Benoît; Böhle, Frederik; López-Martens, Rodrigo; Lifschitz, Agustin

    2017-05-01

    Laser-plasma accelerators are usually driven by 100-TW class laser systems with rather low repetition rates. However, recent years have seen the emergence of laser-plasma accelerators operating with kHz lasers and energies lower than 10 mJ. The high repetition-rate is particularly interesting for applications requiring high stability and high signal-to-noise ratio but lower energy electrons. For example, our group recently demonstrated that kHz laser-driven electron beams could be used to capture ultrafast structural dynamics in Silicon nano-membranes via electron diffraction with picosecond resolution. In these first experiments, electrons were injected in the density gradients located at the plasma exit, resulting in rather low energies in the 100 keV range. The electrons being nonrelativistic, the bunch duration quickly becomes picosecond long. Relativistic energies are required to mitigate space charge effects and maintain femtosecond bunches. In this paper, we will show very recent results where electrons are accelerated in laser-driven wakefields to relativistic energies, reaching up to 5 MeV at kHz repetition rate. The electron energy was increased by nearly two orders of magnitude by using single-cycle laser pulses of 3.5 fs, with only 2.5 mJ of energy. Using such short pulses of light allowed us to resonantly excite high amplitude and nonlinear plasma waves at high plasma density, ne=1.5-2×1020 cm-3, in a regime close to the blow-out regime. Electrons had a peaked distribution around 5 MeV, with a relative energy spread of 30 %. Charges in the 100's fC/shot and up to pC/shot where measured depending on plasma density. The electron beam was fairly collimated, 20 mrad divergence at Full Width Half Maximum. The results show remarkable stability of the beam parameters in terms of beam pointing and electron distribution. 3D PIC simulations reproduce the results very well and indicate that electrons are injected by the ionization of Nitrogen atoms, N5+ to N6

  18. ANALYSIS OF EQUIPMENT PROVISIONS FOR X-RAY DIAGNOSTICS IN THE RUSSIAN FEDERATION

    Directory of Open Access Journals (Sweden)

    N. M. Vishnyakova

    2010-01-01

    Full Text Available Analysis of equipment provisions for X-ray diagnostics in the Russian Federation for the period from 2000 to 2006 is being presented. The article records the lag of Russia behind the countries with high level of public health service development both for total amount of X-ray diagnostic equipment and for the rate of their amount growth. The lag of national X-ray diagnostic equipment is especially high for the equipment for special X-ray examinations. Half of all X-ray equipment in Russia has a life time of 10 and more years. Equipment for the standard X-ray examinations prevails in its structure in contrast to the countries with high level of public health service. More than one third of equipment for fluoroscopy is not equipped with amplifiers of X-ray image. The share of digital X-ray diagnostic equipment for standard X-ray examinations is 5%, while in the economically developed countries mainly digital technologies are applied. Significant differences in the quantitative and qualitative aspects of current state of X-ray diagnostic equipment in the various Federal districts and administrative territories of the Russian Federation are observed.

  19. X-ray lasers: Multicolour emission

    Science.gov (United States)

    Feng, Chao; Deng, Haixiao

    2016-11-01

    The X-ray free-electron laser at the SLAC National Accelerator Laboratory in the US can now generate multicolour X-ray pulses with unprecedented brightness using the fresh-slice technique. The development opens the way to new forms of spectroscopy.

  20. X-Ray Detection Visits the Classroom

    Science.gov (United States)

    Peralta, Luis; Farinha, Ana; Pinto, Ana

    2008-01-01

    Film has been used to detect x-rays since the early days of their discovery by Rontgen. Although nowadays superseded by other techniques, film still provides a cheap means of x-ray detection, making it attractive in high-school or undergraduate university courses. If some sort of quantitative result is required, the film's optical absorbance or…

  1. Accelerator-driven X-ray Sources

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Dinh Cong [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-11-09

    After an introduction which mentions x-ray tubes and storage rings and gives a brief review of special relativity, the subject is treated under the following topics and subtopics: synchrotron radiation (bending magnet radiation, wiggler radiation, undulator radiation, brightness and brilliance definition, synchrotron radiation facilities), x-ray free-electron lasers (linac-driven X-ray FEL, FEL interactions, self-amplified spontaneous emission (SASE), SASE self-seeding, fourth-generation light source facilities), and other X-ray sources (energy recovery linacs, Inverse Compton scattering, laser wakefield accelerator driven X-ray sources. In summary, accelerator-based light sources cover the entire electromagnetic spectrum. Synchrotron radiation (bending magnet, wiggler and undulator radiation) has unique properties that can be tailored to the users’ needs: bending magnet and wiggler radiation is broadband, undulator radiation has narrow spectral lines. X-ray FELs are the brightest coherent X-ray sources with high photon flux, femtosecond pulses, full transverse coherence, partial temporal coherence (SASE), and narrow spectral lines with seeding techniques. New developments in electron accelerators and radiation production can potentially lead to more compact sources of coherent X-rays.

  2. X-raying clumped stellar winds

    CERN Document Server

    Oskinova, L M; Feldmeier, A

    2008-01-01

    X-ray spectroscopy is a sensitive probe of stellar winds. X-rays originate from optically thin shock-heated plasma deep inside the wind and propagate outwards throughout absorbing cool material. Recent analyses of the line ratios from He-like ions in the X-ray spectra of O-stars highlighted problems with this general paradigm: the measured line ratios of highest ions are consistent with the location of the hottest X-ray emitting plasma very close to the base of the wind, perhaps indicating the presence of a corona, while measurements from lower ions conform with the wind-embedded shock model. Generally, to correctly model the emerging X-ray spectra, a detailed knowledge of the cool wind opacities based on stellar atmosphere models is prerequisite. A nearly grey stellar wind opacity for the X-rays is deduced from the analyses of high-resolution X-ray spectra. This indicates that the stellar winds are strongly clumped. Furthermore, the nearly symmetric shape of X-ray emission line profiles can be explained if t...

  3. Cryogenic imaging x-ray spectrometer

    NARCIS (Netherlands)

    Wiegerink, Remco J.; van Baar, J.J.J.; de Boer, J.H.; Ridder, M.L.; Bruijn, M.P.; Germeau, A.; Hoevers, H.F.C.

    2005-01-01

    A micro-calorimeter array consisting of superconducting transition-edge sensors is under development for the X-ray imaging spectrometer on board of ESA's XEUS (X-ray Evolving Universe Spectroscopy) mission. An array of 32 /spl times/ 32 pixels with a pixel size of 250 micron square is envisaged. So

  4. Low Energy X-Ray Diagnostics - 1981.

    Science.gov (United States)

    1981-01-01

    Filtering, and Scattering of Soft X-Rays by Mirrors Victor Rehn Michelson Laboratory, Physics Division Naval Weapons Center, China Lake, California...met with in K.Tregidgo, 18, 2003 (1979). the manufacture of X-ray optical components. In 32. W.P.Linnik, C. R. Acad. Sci. URSS ., 5, 210 (1933). general

  5. Probing Transient Electron Dynamics Using Ultrafast X Rays

    Science.gov (United States)

    Bucksbaum, Philip

    2016-05-01

    Linear x-ray absorption in atoms or molecules creates highly excited multi-electron quantum systems, which relax rapidly by fluorescence or Auger emission. These relaxation rates are usually less than a few femtoseconds in duration, and so they can reveal transient elecronic states in molecules as they undergo photo-induced transformations. I will show recent results from femtosecond x-ray experiments that display this phenomenon. There are efforts underway to push the temporal resolving power of ultrafast x-ray pulses into the attosecond regime, using stronger fields to initiate nonlinear absorption processes such as transient stimulated electronic Raman scattering. I will discuss current progress and future prospects for research in this area. This research is supported through Stanford PULSE Institute, SLAC National Accelerator Lab by the U.S. Department of Energy, Office of Basic Energy Sciences, Atomic, Molecular, and Optical Science Program.

  6. Detection of buried landmine with X-ray backscatter technique

    Energy Technology Data Exchange (ETDEWEB)

    Yuk, Sunwoo [Department of Electronics and Information Engineering, Korea University, Seoul (Korea, Republic of)]. E-mail: sunwoo@korea.ac.kr; Kim, Kwang Hyun [Chosun University, 375, Seosuk-Dong, Dong-Gu, Gwangju (Korea, Republic of); Yi, Yun [Department of Electronics and Information Engineering, Korea University, Seoul (Korea, Republic of)

    2006-11-30

    We describe a continuously operating scanning X-ray imaging system developed for landmine detection based on a backscatter X-ray principle, thus detection is done from the same side as the source. The source operates at 120 kV p and 3 mA. To study the physics of Compton X-ray backscattering, the photon transport factor, backscatter factor (BSF) and backscatter probability (BSP) were simulated using Monte-Carlo calculations using the generalized particle transport program MCNP. Based on the Monte-Carlo analyses results, a mine detecting system has been designed. It potentially has a low false alarm rate and a high detection probability, and a direct imaging facility.

  7. MIXI: Mobile Intelligent X-Ray Inspection System

    Science.gov (United States)

    Arodzero, Anatoli; Boucher, Salime; Kutsaev, Sergey V.; Ziskin, Vitaliy

    2017-07-01

    A novel, low-dose Mobile Intelligent X-ray Inspection (MIXI) concept is being developed at RadiaBeam Technologies. The MIXI concept relies on a linac-based, adaptive, ramped energy source of short X-ray packets of pulses, a new type of fast X-ray detector, rapid processing of detector signals for intelligent control of the linac, and advanced radiography image processing. The key parameters for this system include: better than 3 mm line pair resolution; penetration greater than 320 mm of steel equivalent; scan speed with 100% image sampling rate of up to 15 km/h; and material discrimination over a range of thicknesses up to 200 mm of steel equivalent. Its minimal radiation dose, size and weight allow MIXI to be placed on a lightweight truck chassis.

  8. Geant4 simulation of a filtered X-ray source for radiation damage studies

    Science.gov (United States)

    Guthoff, M.; Brovchenko, O.; de Boer, W.; Dierlamm, A.; Müller, T.; Ritter, A.; Schmanau, M.; Simonis, H.-J.

    2012-05-01

    Geant4 low energy extensions have been used to simulate the X-ray spectra of industrial X-ray tubes with filters for removing the uncertain low energy part of the spectrum in a controlled way. The results are compared with precisely measured X-ray spectra using a silicon drift detector. Furthermore, this paper shows how the different dose rates in silicon and silicon dioxide layers of an electronic device can be deduced from the simulations.

  9. Geant4 Simulation of a filtered X-ray Source for Radiation Damage Studies

    CERN Document Server

    Guthoff, M; de Boer, W; Dierlamm, A; Müller, T; Ritter, A; Schmanau, M; Simonis, H -J

    2012-01-01

    Geant4 low energy extensions have been used to simulate the X-ray spectra of industrial X-ray tubes with filters for removing the uncertain low energy part of the spectrum in a controlled way. The results are compared with precisely measured X-ray spectra using a silicon drift detector. Furthermore, this paper shows how the different dose rates in silicon and silicon dioxide layers of an electronic device can be deduced from the simulations.

  10. X-ray versus gamma irradiation effects on polymers

    Energy Technology Data Exchange (ETDEWEB)

    Croonenborghs, B. [Sterigenics EMEAA, Remylaan 4c box 4, 3018 Leuven (Belgium); Smith, M.A. [Sterigenics International, 10811 Withers Cove Park Drive, Charlotte, NC 28278 (United States); Strain, P. [Sterigenics EMEAA, Remylaan 4c box 4, 3018 Leuven (Belgium)], E-mail: pstrain@eu.sterigenics.com

    2007-11-15

    Today, the most common methods used for medical device sterilisation are by gaseous ethylene oxide and by electron beam or gamma irradiation. With X-ray sterilisation about to enter the market, its material compatibility needs to be assessed at doses typically encountered during a sterilisation process. This paper reports on a study that compares the effects of exposing different types of plastics that are commonly used in medical devices to {sup 60}Co or to 5 MeV X-rays. The dose rate for both irradiation modalities was of the same order of magnitude. Under these conditions, both types of radiation are found to have similar effects on polymer properties.

  11. Metal Foaming Investigated by X-ray Radioscopy

    Directory of Open Access Journals (Sweden)

    Catalina Jiménez

    2011-12-01

    Full Text Available The use of X-ray radioscopy for in-situ studies of metal foam formation and evolution is reviewed. Selected results demonstrate the power of X-ray radioscopy as diagnostic tool for metal foaming. Qualitative analyses of foam nucleation and evolution, drainage development, issues of thermal contact, mold filling, cell wall rupture and more are given. Additionally, quantitative analyses based on series of images of foam expansion yielding coalescence rates, density distributions, etc., are performed by dedicated software. These techniques help us to understand the foaming behavior of metals and to improve both foaming methods and foam quality.

  12. 30S Beam Development and X-ray Bursts

    CERN Document Server

    Kahl, D; Kubono, S; Binh, D N; Chen, J; Hashimoto, T; Hayakawa, S; Kaji, D; Kim, A; Kurihara, Y; Lee, N H; Nishimura, S; Ohshiro, Y; nia, K Setoodeh; Wakabayashi, Y; Yamaguchi, H; 10.1063/1.3362583

    2010-01-01

    Over the past three years, we have worked on developing a well-characterized 30S radioactive beam to be used in a future experiment aiming to directly measure the 30S(alpha,p) stellar reaction rate within the Gamow window of Type I X-ray bursts. The importance of the 30S(alpha,p) reaction to X-ray bursts is discussed. Given the astrophysical motivation, the successful results of and challenges involved in the production of a low-energy 30S beam are detailed. Finally, an overview of our future plans regarding this on-going project are presented.

  13. New Insights into X-ray Binaries

    CERN Document Server

    Casares, Jorge

    2009-01-01

    X-ray binaries are excellent laboratories to study collapsed objects. On the one hand, transient X-ray binaries contain the best examples of stellar-mass black holes while persistent X-ray binaries mostly harbour accreting neutron stars. The determination of stellar masses in persistent X-ray binaries is usually hampered by the overwhelming luminosity of the X-ray heated accretion disc. However, the discovery of high-excitation emission lines from the irradiated companion star has opened new routes in the study of compact objects. This paper presents novel techniques which exploits these irradiated lines and summarises the dynamical masses obtained for the two populations of collapsed stars: neutron stars and black holes.

  14. Perspectives of medical X-ray imaging

    Energy Technology Data Exchange (ETDEWEB)

    Freudenberger, J. E-mail: joerg.freudenberger@med.siemens.de; Hell, E.; Knuepfer, W

    2001-06-21

    While X-ray image intensifiers (XII), storage phosphor screens and film-screen systems are still the work horses of medical imaging, large flat panel solid state detectors using either scintillators and amorphous silicon photo diode arrays (FD-Si), or direct X-ray conversion in amorphous selenium are reaching maturity. The main advantage with respect to image quality and low patient dose of the XII and FD-Si systems is caused by the rise of the Detector Quantum Efficiency originating from the application of thick needle-structured phosphor X-ray absorbers. With the detectors getting closer to an optimal state, further progress in medical X-ray imaging requires an improvement of the usable source characteristics. The development of clinical monochromatic X-ray sources of high power would not only allow an improved contrast-to-dose ratio by allowing smaller average photon energies in applications but would also lead to new imaging techniques.

  15. Perspectives of medical X-ray imaging

    Science.gov (United States)

    Freudenberger, J.; Hell, E.; Knüpfer, W.

    2001-06-01

    While X-ray image intensifiers (XII), storage phosphor screens and film-screen systems are still the work horses of medical imaging, large flat panel solid state detectors using either scintillators and amorphous silicon photo diode arrays (FD-Si), or direct X-ray conversion in amorphous selenium are reaching maturity. The main advantage with respect to image quality and low patient dose of the XII and FD-Si systems is caused by the rise of the Detector Quantum Efficiency originating from the application of thick needle-structured phosphor X-ray absorbers. With the detectors getting closer to an optimal state, further progress in medical X-ray imaging requires an improvement of the usable source characteristics. The development of clinical monochromatic X-ray sources of high power would not only allow an improved contrast-to-dose ratio by allowing smaller average photon energies in applications but would also lead to new imaging techniques.

  16. An X-ray view of quasars

    CERN Document Server

    Singh, K P

    2013-01-01

    I present an overview of observational studies of quasars of all types, with particular emphasis on X-ray observational studies. The presentation is based on the most popularly accepted unified picture of quasars - collectively referred to as AGN (active galactic nuclei) in this review. Characteristics of X-ray spectra and X-ray variability obtained from various X-ray satellites over the last 5 decades have been presented and discussed. The contribution of AGN in understanding the cosmic X-ray background is discussed very briefly. Attempt has been made to provide up-to-date information; however, this is a vast subject and this presentation is not intended to be comprehensive.

  17. LOBSTER - New Space X-Ray telescopes

    Energy Technology Data Exchange (ETDEWEB)

    Hudec, R. [Astronomical Institute, Academy of Sciences of the Czech Republic, CZ-251 65 Ondrejov (Czech Republic); Pina, L. [Faculty of Nuclear Science, Czech Technical University, Prague (Czech Republic); Simon, V. [Astronomical Institute, Academy of Sciences of the Czech Republic, CZ-251 65 Ondrejov (Czech Republic); Sveda, L. [Faculty of Nuclear Science, Czech Technical University, Prague (Czech Republic); Inneman, A.; Semencova, V. [Center for Advanced X-ray Technologies, Reflex, Prague (Czech Republic); Skulinova, M. [Astronomical Institute, Academy of Sciences of the Czech Republic, CZ-251 65 Ondrejov (Czech Republic)

    2007-04-15

    We discuss the technological and scientific aspects of fully innovative very wide-field X-ray telescopes with high sensitivity. The prototypes of Lobster telescopes designed, developed and tested are very promising, allowing the proposals for space projects with very wide-field Lobster Eye X-ray optics to be considered for the first time. The novel telescopes will monitor the sky with unprecedented sensitivity and angular resolution of order of 1 arcmin. They are expected to contribute essentially to study of various astrophysical objects such as AGN, SNe, Gamma-ray bursts (GRBs), X-ray flashes (XRFs), galactic binary sources, stars, CVs, X-ray novae, various transient sources, etc. For example, the Lobster optics based X-ray All Sky Monitor is capable to detect around 20 GRBs and 8 XRFs yearly and this will surely significantly contribute to the related science.

  18. High Energy Vision: Processing X-rays

    CERN Document Server

    DePasquale, Joseph; Edmonds, Peter

    2015-01-01

    Astronomy is by nature a visual science. The high quality imagery produced by the world's observatories can be a key to effectively engaging with the public and helping to inspire the next generation of scientists. Creating compelling astronomical imagery can, however, be particularly challenging in the non-optical wavelength regimes. In the case of X-ray astronomy, where the amount of light available to create an image is severely limited, it is necessary to employ sophisticated image processing algorithms to translate light beyond human vision into imagery that is aesthetically pleasing while still being scientifically accurate. This paper provides a brief overview of the history of X-ray astronomy leading to the deployment of NASA's Chandra X-ray Observatory, followed by an examination of the specific challenges posed by processing X-ray imagery. The authors then explore image processing techniques used to mitigate such processing challenges in order to create effective public imagery for X-ray astronomy. ...

  19. Globular Cluster X-ray Sources

    CERN Document Server

    Verbunt, F

    2004-01-01

    After a brief historical overview we discuss the luminous X-ray sources in globular clusters of our Galaxy. This is followed by an overview of the very luminous X-ray sources studied in globular clusters of 14 other galaxies, and a discussion of their formation and the relation to X-ray sources outside globular clusters. We describe the discovery and classification of low-luminosity X-ray sources, and end the review with some remarks on the formation and evolution of X-ray sources in globular clusters. Observational results are summarized in three tables. Comments are very welcome. Please send them to F.W.M.Verbunt@astro.uu.nl and lewin@mit.edu.

  20. X-Rays from Green Pea Analogs

    Science.gov (United States)

    Brorby, Matthew

    2014-09-01

    X-rays may have contributed to the heating and reionization of the IGM in the early universe. High mass X-ray binaries (HMXB) within small, low-metallicity galaxies are expected to be the main source of X-rays at this time. Since studying these high-redshift galaxies is currently impossible, we turn to local analogs that have the same properties the galaxies in the early are expected to have. A number of recent studies have shown an enhanced number of HMXBs in nearby low metallicity galaxies. We propose to observe a sample of metal-deficient luminous compact galaxies (LCG) in order to determine if the X-ray luminosity is enhanced relative to SFR, thereby providing further evidence to the importance of X-rays in the early universe.