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Sample records for high-brightness x-ray pulses

  1. Short Pulse High Brightness X-ray Production with the PLEIADES Thomson Scattering Source

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, S G; Barty, C P J; Betts, S M; Brown, W J; Crane, J K; Cross, R R; Fittinghoff, D N; Gibson, D J; Hartemann, F V; Kuba, J; LaSage, G P; Rosenzweig, J B; Slaughter, D R; Springer, P T; Tremaine, A M

    2003-07-01

    We describe PLEIADES, a compact, tunable, high-brightness, ultra-short pulse, Thomson x-ray source. The peak brightness of the source is expected to exceed 10{sup 20} photons/s/0.1% bandwidth/mm{sup 2}/mrad{sup 2}. Initial results are reported and compared to theoretical calculations.

  2. High-brightness X-ray free-electron laser with an optical undulator by pulse shaping.

    Science.gov (United States)

    Chang, Chao; Liang, Jinyang; Hei, Dongwei; Becker, Michael F; Tang, Kelei; Feng, Yiping; Yakimenko, Vitaly; Pellegrini, Claudio; Wu, Juhao

    2013-12-30

    A normal-incident flattop laser with a tapered end is proposed as an optical undulator to achieve a high-gain and high-brightness X-ray free electron laser (FEL). The synchronic interaction of an electron bunch with the normal incident laser is realized by tilting the laser pulse front. The intensity of the flattop laser is kept constant during the interaction time of the electron bunch and the laser along the focal plane of a cylindrical lens. Optical shaping to generate the desired flattop pulse with a tapered end from an original Gaussian pulse distribution is designed and simulated. The flattop laser with a tapered end can enhance the X-ray FEL beyond the exponential growth saturation power by one order to reach 1 Gigawatt as compared to that without a tapered end. The peak brightness can reach 1030 photons/mm2/mrad2/s/0.1% bandwidth, more than 10 orders brighter than the conventional incoherent Thompson Scattering X-ray source.

  3. Transform-Limited X-Ray Pulse Generation from a High Brightness Self-Amplified Spontaneous Emission Free-Electron Laser

    CERN Document Server

    McNeil, B W J; Dunning, D J

    2012-01-01

    A method to achieve High-Brightness Self-Amplified Spontaneous Emission (HB-SASE) in the Free Electron Laser (FEL) is described. The method uses repeated non-equal electron beam delays to de-localise the collective FEL interaction and break the radiation coherence length dependence on the FEL cooperation length. The method requires no external seeding or photon optics and so is applicable at any wavelength or repetition rate. It is demonstrated using linear theory and numerical simulations that the radiation coherence length can be increased by approximately two orders of magnitude over SASE with a corresponding increase in spectral brightness. Examples are shown of HB-SASE generating transform-limited FEL pulses in the soft X-ray and near transform-limited pulses in the hard X-ray. Such pulses may greatly benefit existing applications and may also open up new areas of scientific research.

  4. Generating coherent soft x-ray pulses in the water window with a high-brightness seeded free-electron laser

    CERN Document Server

    Zhou, Kaishang; Deng, Haixiao; Wang, Dong

    2016-01-01

    We propose a new scheme to generate high-brightness and temporal coherent soft x-ray radiation in a seeded free-electron laser. The proposed scheme is based the coherent harmonic generation (CHG) and superradiant principles. A CHG scheme is first used to generate coherent signal at ultra-high harmonics of the seed. This coherent signal is then amplified by a series of chicane-undulator modules via the fresh bunch and superradiant processes in the following radiator. Using a representative of realistic set of parameters, three-dimensional simulations have been carried out and the simulations results demonstrated that 10 GW-level ultra-short coherent radiation pulses in the water window can be achieved by using the proposed technique.

  5. Generating high-brightness and coherent soft x-ray pulses in the water window with a seeded free-electron laser

    Directory of Open Access Journals (Sweden)

    Kaishang Zhou

    2017-01-01

    Full Text Available We propose a new scheme to generate high-brightness and temporal coherent soft x-ray radiation in a seeded free-electron laser. The proposed scheme is based on the coherent harmonic generation (CHG and superradiant principles. A CHG scheme is first used to generate a coherent signal at ultrahigh harmonics of the seed. This coherent signal is then amplified by a series of chicane-undulator modules via the fresh bunch and superradiant processes in the following radiator. Using a representative of a realistic set of parameters, three-dimensional simulations have been carried out and the simulations results demonstrated that 10 GW-level ultrashort (∼20  fs coherent radiation pulses in the water window can be achieved by using a 1.6 GeV electron beam based on the proposed technique.

  6. 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.

  7. First results from the high-brightness x-ray spectroscopy beamline at ALS

    Energy Technology Data Exchange (ETDEWEB)

    Perera, R.C.C.; Ng, W.; Jones, G. [Lawrence Berkeley National Lab., CA (United States)] [and others

    1997-04-01

    Beamline 9.3.1 at the Advanced Light Source (ALS) is a windowless beamline, covering the 1-6 keV photon-energy range, designed to achieve the goal of high brightness at the sample for use in the X-ray Atomic and Molecular Spectroscopy (XAMS) science, surface and interface science, biology and x-ray optical development programs at ALS. X-ray absorption and time of flight photo emission measurements in 2 - 5 keV photon energy in argon along with the flux, resolution, spot size and stability of the beamline will be discussed. Prospects for future XAMS measurements will also be presented.

  8. High-brightness beamline for x-ray spectroscopy at the ALS

    Energy Technology Data Exchange (ETDEWEB)

    Perera, R.C.C.; Jones, G. [Ernest Orlando Lawrence Berkeley National Lab., CA (United States); Lindle, D.W. [Univ. of Nevada, Las Vegas, NV (United States)

    1997-04-01

    Beamline 9.3.1 at the Advanced Light Source (ALS) is a windowless beamline, covering the 1-6 keV photon-energy range, designed to achieve the goals of high energy resolution, high flux, and high brightness at the sample. When completed later this year, it will be the first ALS monochromatic hard x-ray beamline, and its brightness will be an order of magnitude higher than presently available in this energy range. In addition, it will provide flux and resolution comparable to any other beamline now in operation. To achieve these goals, two technical improvements, relative to existing x-ray beamlines, were incorporated. First, a somewhat novel optical design for x-rays, in which matched toroidal mirrors are positioned before and after the double-crystal monochromator, was adopted. This configuration allows for high resolution by passing a collimated beam through the monochromator, and for high brightness by focusing the ALS source on the sample with unit magnification. Second, a new {open_quotes}Cowan type{close_quotes} double-crystal monochromator based on the design used at NSLS beamline X-24A was developed. The measured mechanical precision of this new monochromator shows significant improvement over existing designs, without using positional feedback available with piezoelectric devices. Such precision is essential because of the high brightness of the radiation and the long distance (12 m) from the source (sample) to the collimating (focusing) mirror. This combination of features will provide a bright, high resolution, and stable x-ray beam for use in the x-ray spectroscopy program at the ALS.

  9. A study on materials of steels by high brightness X-ray

    CERN Document Server

    Tsuzaki, K; Umezawa, O; Hara, T; Takahashi, T; Omura, T; Hayakawa, M; Yamauchi, Y

    2001-01-01

    As the survey study on materials analysis of steels using high brightness X-ray, under aiming to clarify direct experimental facts on deformations, failure phenomena, and metal textures forming at interior portions of bulk materials, feasibility on materials research and development using SPring-8 was surveyed. Its concrete items were summarized to fields shown as follows: 1) acquirement of foundation on synchrotron X-ray, 2) visualization of cracks and artificial cracks in metal bulk samples by using refraction imaging (point light source topography), 3) visualization of the second phase in the metal bulk samples by using refraction imaging, and 4) speciation of carbon elements in steel cords by Moessbauer spectroscopy. Together with clarifying problems more and more by the survey and some experiments, subjects and understandings vacantly considered at standpoints of materials researchers could be arranged and defined. (G.K.)

  10. High-brightness laser plasma soft X-ray source using a double-stream gas puff target irradiated with the Prague Asterix Laser System (PALS)

    Energy Technology Data Exchange (ETDEWEB)

    Fiedorowicz, H.; Bartnik, A.; Juha, L.; Jungwirth, K.; Kralikova, B.; Krasa, J.; Kubat, P.; Pfeifer, M.; Pina, L.; Prchal, P.; Rohlena, K.; Skala, J.; Ullschmied, J.; Horvath, M.; Wawer, J

    2004-01-14

    High brightness laser plasma soft X-ray source based on a recently developed double-stream gas puff target irradiated with 0.5 ns laser pulses with energies up to 700 J from the Prague Asterix Laser System (PALS) is presented. The gas puff target was created by pulsed injection of xenon into a hollow stream of helium using an electromagnetic valve system with the double-nozzle setup. Soft X-ray emission was measured using the transmission grating spectrograph coupled to a CCD camera and the calibrated silicon photodiodes. The absolute soft X-ray production was determined to be 160 J for 540 J of laser energy, giving the soft X-ray conversion efficiency of about 30%. The source has been used in initial experiments on soft X-ray ablation of organic polymers and elemental solids.

  11. Short X-ray pulses from third-generation light sources.

    Science.gov (United States)

    Stepanov, A G; Hauri, C P

    2016-01-01

    High-brightness X-ray radiation produced by third-generation synchrotron light sources (TGLS) has been used for numerous time-resolved investigations in many different scientific fields. The typical time duration of X-ray pulses delivered by these large-scale machines is about 50-100 ps. A growing number of time-resolved studies would benefit from X-ray pulses with two or three orders of magnitude shorter duration. Here, techniques explored in the past for shorter X-ray pulse emission at TGLS are reviewed and the perspective towards the realisation of picosecond and sub-picosecond X-ray pulses are discussed.

  12. 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

  13. 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

  14. 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.

  15. Ultrafast X-ray pulse measurement method

    CERN Document Server

    Geloni, Gianluca; Saldin, Evgeni

    2010-01-01

    In this paper we describe a measurement technique capable of resolving femtosecond X-ray pulses from XFEL facilities. Since these ultrashort pulses are themselves the shortest event available, our measurement strategy is to let the X-ray pulse sample itself. Our method relies on the application of a "fresh" bunch technique, which allows for the production of a seeded X-ray pulse with a variable delay between seed and electron bunch. The shot-to-shot averaged energy per pulse is recorded. It turns out that one actually measures the autocorrelation function of the X-ray pulse, which is related in a simple way to the actual pulse width. For implementation of the proposed technique, it is sufficient to substitute a single undulator segment with a short magnetic chicane. The focusing system of the undulator remains untouched, and the installation does not perturb the baseline mode of operation. We present a feasibility study and we make exemplifications with typical parameters of an X-ray FEL.

  16. Real-Time Observation of Laser Heated Metals with High Brightness Monochromatic X-Ray Techniques at Present and Their Future Prospects

    Science.gov (United States)

    Daido, H.; Shobu, T.; Yamada, T.; Yamashita, S.; Sugihara, K.; Nishimura, A.; Muramatsu, T.

    We present the x-ray techniques for characterizing laser heated metals for welding and cutting techniques. At present, with an undulator (70 keV) as well as bending magnet (30 keV) sources at SPring-8 as a probe source, CW 300 W Ytterbium fiber laser irradiates an Aluminum slab as a sample. Simultaneously the x-ray beam probes the sample for real time observation of a molten pool. We observe the convection indicated by the motion of tungsten based particles as a tracer in the molten pool. During the cooling phase, the molten metal is solidified with residual stresses which are affected by the heating and convection processes. In this experiment the time and space resolution are ˜milli-second and several tens of μm, respectively. On the other hand, microscopic short transient phenomena also play a significant role for the quality of a solidified material. For this purpose, we need high energy short pulse x-ray sources. We try to discuss on the capability and limitation of present x-ray sources and the prospect of an ultra high brightness x-ray source as a complementary source for full characterization of the laser heated and cooling processes of metals.

  17. PULSED CAPILLARY DISCHARGE CHARACTERIZATION FOR SOFT X-RAY MICROSCOPY APPLICATIONS

    OpenAIRE

    VALDIVIA LEIVA; MARIA PIA

    2011-01-01

    The hollow cathode capillary discharge is of great interest as a high brightness, short pulse soft x-ray source. This thesis presents work done in the development, modifications, and subsequent characterization of a compact plasma source comprised of a pulsed capillary discharge exploiting hollow cathode dynamics. The low inductance, low stored energy, source is optimized using optical, electrical, x-ray, and e-beam diagnostics. The effect of parameters on the capillary phys...

  18. X-Ray Scattering Applications Using Pulsed X-Ray Sources

    Energy Technology Data Exchange (ETDEWEB)

    Larson, B.C.

    1999-05-23

    Pulsed x-ray sources have been used in transient structural phenomena investigations for over fifty years; however, until the advent of synchrotrons sources and the development of table-top picosecond lasers, general access to ligh temporal resolution x-ray diffraction was relatively limited. Advances in diffraction techniques, sample excitation schemes, and detector systems, in addition to IncEased access to pulsed sources, have ld tO what is now a diverse and growing array of pulsed-source measurement applications. A survey of time-resolved investigations using pulsed x-ray sources is presented and research opportunities using both present and planned pulsed x-ray sources are discussed.

  19. X-ray Chirped Pulse Amplification: towards GW Soft X-ray Lasers

    Directory of Open Access Journals (Sweden)

    Marta Fajardo

    2013-07-01

    Full Text Available Extensive modeling of the seeding of plasma-based soft X-ray lasers is reported in this article. Seminal experiments on amplification in plasmas created from solids have been studied in detail and explained. Using a transient collisional excitation scheme, we show that a 18 µJ, 80 fs fully coherent pulse is achievable by using plasmas pumped by a compact 10 Hz laser. We demonstrate that direct seeding of plasmas created by nanosecond lasers is not efficient. Therefore, we propose and fully study the transposition to soft X-rays of the Chirped Pulse Amplification (CPA technique. Soft X-ray pulses with energy of 6 mJ and 200 fs duration are reachable by seeding plasmas pumped by compact 100 J, sub-ns, 1 shot/min lasers. These soft X-ray lasers would reach GW power, corresponding to an increase of 100 times as compared to the highest peak power achievable nowadays in the soft X-ray region (30 eV–1 keV. X-ray CPA is opening new horizon for soft x-ray ultra-intense sources.

  20. Establishing nonlinearity thresholds with ultraintense X-ray pulses.

    Science.gov (United States)

    Szlachetko, Jakub; Hoszowska, Joanna; Dousse, Jean-Claude; Nachtegaal, Maarten; Błachucki, Wojciech; Kayser, Yves; Sà, Jacinto; Messerschmidt, Marc; Boutet, Sebastien; Williams, Garth J; David, Christian; Smolentsev, Grigory; van Bokhoven, Jeroen A; Patterson, Bruce D; Penfold, Thomas J; Knopp, Gregor; Pajek, Marek; Abela, Rafael; Milne, Christopher J

    2016-09-13

    X-ray techniques have evolved over decades to become highly refined tools for a broad range of investigations. Importantly, these approaches rely on X-ray measurements that depend linearly on the number of incident X-ray photons. The advent of X-ray free electron lasers (XFELs) is opening the ability to reach extremely high photon numbers within ultrashort X-ray pulse durations and is leading to a paradigm shift in our ability to explore nonlinear X-ray signals. However, the enormous increase in X-ray peak power is a double-edged sword with new and exciting methods being developed but at the same time well-established techniques proving unreliable. Consequently, accurate knowledge about the threshold for nonlinear X-ray signals is essential. Herein we report an X-ray spectroscopic study that reveals important details on the thresholds for nonlinear X-ray interactions. By varying both the incident X-ray intensity and photon energy, we establish the regimes at which the simplest nonlinear process, two-photon X-ray absorption (TPA), can be observed. From these measurements we can extract the probability of this process as a function of photon energy and confirm both the nature and sub-femtosecond lifetime of the virtual intermediate electronic state.

  1. Establishing nonlinearity thresholds with ultraintense X-ray pulses

    Science.gov (United States)

    Szlachetko, Jakub; Hoszowska, Joanna; Dousse, Jean-Claude; Nachtegaal, Maarten; Błachucki, Wojciech; Kayser, Yves; Sà, Jacinto; Messerschmidt, Marc; Boutet, Sebastien; Williams, Garth J.; David, Christian; Smolentsev, Grigory; van Bokhoven, Jeroen A.; Patterson, Bruce D.; Penfold, Thomas J.; Knopp, Gregor; Pajek, Marek; Abela, Rafael; Milne, Christopher J.

    2016-09-01

    X-ray techniques have evolved over decades to become highly refined tools for a broad range of investigations. Importantly, these approaches rely on X-ray measurements that depend linearly on the number of incident X-ray photons. The advent of X-ray free electron lasers (XFELs) is opening the ability to reach extremely high photon numbers within ultrashort X-ray pulse durations and is leading to a paradigm shift in our ability to explore nonlinear X-ray signals. However, the enormous increase in X-ray peak power is a double-edged sword with new and exciting methods being developed but at the same time well-established techniques proving unreliable. Consequently, accurate knowledge about the threshold for nonlinear X-ray signals is essential. Herein we report an X-ray spectroscopic study that reveals important details on the thresholds for nonlinear X-ray interactions. By varying both the incident X-ray intensity and photon energy, we establish the regimes at which the simplest nonlinear process, two-photon X-ray absorption (TPA), can be observed. From these measurements we can extract the probability of this process as a function of photon energy and confirm both the nature and sub-femtosecond lifetime of the virtual intermediate electronic state.

  2. Methods of Attosecond X-Ray Pulse Generation

    CERN Document Server

    Zholents, Alexander

    2005-01-01

    Our attitude towards attosecond x-ray pulses has changed dramatically over the past several years. Not long ago x-ray pulses with a duration of a few hundred attoseconds were just science fiction for most of us, but they are already a tool for some researchers in present days. Breakthrough progress in the generation of solitary soft x-ray pulses of attosecond duration has been made by the laser community. Following this lead, people in the free electron laser community have begun to develop new ideas on how to generate attosecond x-ray pulses in the hard x-ray energy range. In this report I will review some of these ideas.

  3. Experimental and theoretical characterisation of short pulse X ray lasers

    CERN Document Server

    Strati, F

    2002-01-01

    Since the demonstration in 1984 of x-ray laser action in Ne-like Se at 20.6 and 20.9 nm, much experimental and theoretical effort has been ongoing to investigate different lasing schemes. Aims in this research include improving pumping efficiency, beam quality and overall energy output of the demonstrated x-ray lasers and the production of lasing at shorter wavelengths. The envisaged and demonstrated applications of x-ray lasers utilise their short wavelength, high brightness and coherence. Examples of potential applications include x-ray imaging and holography of biological materials in the water window region (2.3 - 4.4 nm), x-ray photolithography for the fabrication of microcircuits and structures below the micron scale and x-ray interferometry, deflectometry and radiography of dense plasma environments of interest in inertial confinement fusion and astrophysics. Soft x-ray laser action has been demonstrated in various plasma active media with wavelengths ranging from 3.5 nm to 40.0 nm and above. However, ...

  4. X-ray pulse wavefront metrology using speckle tracking

    Energy Technology Data Exchange (ETDEWEB)

    Berujon, Sebastien, E-mail: berujon@esrf.eu; Ziegler, Eric; Cloetens, Peter [European Synchrotron Radiation Facility, BP-220, F-38043 Grenoble (France)

    2015-05-09

    The theoretical description and experimental implementation of a speckle-tracking-based instrument which permits the characterisation of X-ray pulse wavefronts. An instrument allowing the quantitative analysis of X-ray pulsed wavefronts is presented and its processing method explained. The system relies on the X-ray speckle tracking principle to accurately measure the phase gradient of the X-ray beam from which beam optical aberrations can be deduced. The key component of this instrument, a semi-transparent scintillator emitting visible light while transmitting X-rays, allows simultaneous recording of two speckle images at two different propagation distances from the X-ray source. The speckle tracking procedure for a reference-less metrology mode is described with a detailed account on the advanced processing schemes used. A method to characterize and compensate for the imaging detector distortion, whose principle is also based on speckle, is included. The presented instrument is expected to find interest at synchrotrons and at the new X-ray free-electron laser sources under development worldwide where successful exploitation of beams relies on the availability of an accurate wavefront metrology.

  5. Ultrafast X-ray Science at the Sub-Picosecond Pulse Source

    Energy Technology Data Exchange (ETDEWEB)

    Gaffney, Kelly J.; /SLAC, SSRL

    2005-09-30

    The ultrafast, high brightness x-ray free electron laser (XFEL) sources of the future have the potential to revolutionize the study of time dependent phenomena in the natural sciences. These linear accelerator (linac) sources will generate femtosecond (fs) x-ray pulses with peak flux comparable to conventional lasers, and far exceeding all other x-ray sources. The Stanford Linear Accelerator Center (SLAC) has pioneered the development of linac science and technology for decades, and since 2000 SLAC and the Stanford Synchrotron Radiation Laboratory (SSRL) have focused on the development of linac based ultrafast electron and x-ray sources. This development effort has led to the creation of a new x-ray source, called the Sub-Picosecond Pulse Source (SPPS), which became operational in 2003 [1]. The SPPS represents the first step toward the world's first hard x-ray free electron laser (XFEL), the Linac Coherent Light Source (LCLS), due to begin operation at SLAC in 2009. The SPPS relies on the same linac-based acceleration and electron bunch compression schemes that will be used at the LCLS to generate ultrashort, ultrahigh peak brightness electron bunches [2]. This involves creating an energy chirp on the electron bunch during acceleration and subsequent compression of the bunch in a series of energy-dispersive magnetic chicanes to create 80 fs electron pulses. The SPPS has provided an excellent opportunity to demonstrate the viability of these electron bunch compression schemes and to pursue goals relevant to the utilization and validation of XFEL light sources.

  6. Techniques for synchronization of X-Ray pulses to the pump laser in an ultrafast X-Ray facility

    Energy Technology Data Exchange (ETDEWEB)

    Corlett, J.N.; Doolittle, L.; Schoenlein, R.; Staples, J.; Wilcox, R.; Zholents, A.

    2003-05-06

    Accurate timing of ultrafast x-ray probe pulses emitted from a synchrotron radiation source with respect to the signal initiating a process in the sample under study is critical for the investigation of structural dynamics in the femtosecond regime. We describe schemes for achieving accurate timing of femtosecond x-ray synchrotron radiation pulses relative to a pump laser, where x-rays pulses of <100 fs duration are generated from the proposed LUX source based on a recirculating superconducting linac. We present a description of the timing signal generation and distribution systems to minimize timing jitter of the x-rays relative to the experimental lasers.

  7. Conceptual design of a high-brightness linac for soft X-ray SASE-FEL source

    Energy Technology Data Exchange (ETDEWEB)

    Alesini, D.; Bertolucci, S.; Biagini, M.E.; Biscari, C.; Boni, R.; Boscolo, M.; Castellano, M.; Clozza, A.; Pirro, G.D.G. Di; Drago, A.; Esposito, A.; Ferrario, M. E-mail: massimo.ferrario@lnf.infn.it; Fusco, V.; Gallo, A.; Ghigo, A.; Guiducci, S.; Incurvati, M.; Laurelli, P.; Ligi, C.; Marcellini, F.; Migliorati, M.; Milardi, C.; Palumbo, L.; Pellegrino, L.; Preger, M.; Raimondi, P.; Ricci, R.; Sanelli, C.; Sgamma, F.; Spataro, B.; Serio, M.; Stecchi, A.; Stella, A.; Tazzioli, F.; Vaccarezza, C.; Vescovi, M.; Vicario, C.; Zobov, M.; Acerbi, E.; Alessandria, F.; Barni, D.; Bellomo, G.; Birattari, C.; Bonardi, M.; Boscolo, I.; Bosotti, A.; Broggi, F.; Cialdi, S.; DeMartinis, C.; Giove, D.; Maroli, C.; Michelato, P.; Monaco, L.; Pagani, C.; Petrillo, V.; Pierini, P.; Serafini, L.; Sertore, D.; Volpini, G.; Chiadroni, E.; Felici, G.; Levi, D.; Mastrucci, M.; Mattioli, M.; Medici, G.; Petrarca, G.S.; Catani, L.; Cianchi, A.; D' Angelo, A.; Salvo, R.D.R. Di; Fantini, A.; Moricciani, D.; Schaerf, C.; Bartolini, R.; Ciocci, F.; Dattoli, G.; Doria, A.; Flora, F.; Gallerano, G.P.; Giannessi, L.; Giovenale, E.; Messina, G.; Mezi, L.; Ottaviani, P.L.; Picardi, L.; Quattromini, M.; Renieri, A.; Ronsivalle, C.; Avaldi, L.; Carbone, C.; Cricenti, A.; Pifferi, A.; Perfetti, P.; Prosperi, T.; Albertini, V.R.V. Rossi; Quaresima, C.; Zema, N

    2003-07-11

    FELs based on SASE are believed to be powerful tools to explore the frontiers of basic sciences, from physics to chemistry to biology. Intense R and D programs have started in the USA and Europe in order to understand the SASE physics and to prove the feasibility of these sources. The allocation of considerable resources in the Italian National Research Plan (PNR) brought about the formation of a CNR-ENEA-INFN-University of Roma 'Tor Vergata' study group. A conceptual design study has been developed and possible schemes for linac sources have been investigated, leading to the SPARX proposal. We report in this paper the results of a preliminary start to end simulation concerning one option we are considering based on an S-band normal conducting linac with high-brightness photoinjector integrated in an RF compressor.

  8. X-ray pulse wavefront metrology using speckle tracking.

    Science.gov (United States)

    Berujon, Sebastien; Ziegler, Eric; Cloetens, Peter

    2015-07-01

    An instrument allowing the quantitative analysis of X-ray pulsed wavefronts is presented and its processing method explained. The system relies on the X-ray speckle tracking principle to accurately measure the phase gradient of the X-ray beam from which beam optical aberrations can be deduced. The key component of this instrument, a semi-transparent scintillator emitting visible light while transmitting X-rays, allows simultaneous recording of two speckle images at two different propagation distances from the X-ray source. The speckle tracking procedure for a reference-less metrology mode is described with a detailed account on the advanced processing schemes used. A method to characterize and compensate for the imaging detector distortion, whose principle is also based on speckle, is included. The presented instrument is expected to find interest at synchrotrons and at the new X-ray free-electron laser sources under development worldwide where successful exploitation of beams relies on the availability of an accurate wavefront metrology.

  9. Portable pulse X-ray apparatus with gas insulation

    CERN Document Server

    Avilov, E A; Kanunov, I M

    2001-01-01

    There are presented the data on development,investigation and application of a pulse X-ray apparatus with gas insulation.There are described circuit and design solutions for a 90 kV apparatus to be used in medical X-ray diagnostics and 200 kV apparatus to be applied for the researches of high-speed processes.There are demonstrated the advantages of using gas under pressure as insulating medium.There are presented basic output characteristics of the devices.

  10. Pulse pile-up in hard X-ray detector systems. [for solar X-rays

    Science.gov (United States)

    Datlowe, D. W.

    1975-01-01

    When pulse-height spectra are measured by a nuclear detection system at high counting rates, the probability that two or more pulses will arrive within the resolving time of the system is significant. This phenomenon, pulse pile-up, distorts the pulse-height spectrum and must be considered in the interpretation of spectra taken at high counting rates. A computational technique for the simulation of pile-up is developed. The model is examined in the three regimes where (1) the time between pulses is long compared to the detector-system resolving time, (2) the time between pulses is comparable to the resolving time, and (3) many pulses occur within the resolving time. The technique is used to model the solar hard X-ray experiment on the OSO-7 satellite; comparison of the model with data taken during three large flares shows excellent agreement. The paper also describes rule-of-thumb tests for pile-up and identifies the important detector design factors for minimizing pile-up, i.e., thick entrance windows and short resolving times in the system electronics.

  11. Synchronization of x-ray pulses to the pump laser in an ultrafast x-ray facility

    Energy Technology Data Exchange (ETDEWEB)

    Corlett, J.N.; Barry, W.; Byrd, J.M.; Schoenlein, R.; Zholents, A.

    2002-05-30

    Accurate timing of ultrafast x-ray probe pulses emitted from a synchrotron radiation source with respect to a pump laser exciting processes in the sample under study is critical for the investigation of structural dynamics in the femtosecond regime. We describe a scheme for synchronizing femtosecond x-ray pulses relative to a pump laser. X-ray pulses of <100 fs duration are generated from a proposed source based on a recirculating superconducting linac [1,2,3]. Short x-ray pulses are obtained by a process of electron pulse compression, followed by transverse temporal correlation of the electrons, and ultimately x-ray pulse compression. Timing of the arrival of the x-ray pulse with respect to the pump laser is found to be dominated by the operation of the deflecting cavities which provide the transverse temporal correlation of the electrons. The deflecting cavities are driven from a highly stable RF signal derived from a modelocked laser oscillator which is also the origin of the pump l aser pulses.

  12. Single molecule imaging with longer x-ray laser pulses

    CERN Document Server

    Martin, Andrew V; Caleman, Carl; Quiney, Harry M

    2015-01-01

    In serial femtosecond crystallography, x-ray laser pulses do not need to outrun all radiation damage processes because Bragg diffraction exceeds the damage-induced background scattering for longer pulses ($\\sim$ 50--100 fs). This is due to a "self-gating pulse" effect whereby damage terminates Bragg diffraction prior to the pulse completing its passage through the sample, as if that diffraction were produced by a shorter pulse of equal fluence. We show here that a similar gating effect applies to single molecule diffraction with respect to spatially uncorrelated damage processes like ionization and ion diffusion. The effect is clearly seen in calculations of the diffraction contrast, by calculating the diffraction of average structure separately to the diffraction from statistical fluctuations of the structure due to damage ("damage noise"). Our results suggest that sub-nanometer single molecule imaging with longer pulses, like those produced at currently operating facilities, should not yet be ruled out. The...

  13. Comparison of short pulse generation schemes for a soft x-ray free electron laser

    Science.gov (United States)

    Martin, I. P. S.; Bartolini, R.

    2011-03-01

    In this paper we study the performance of two complementary short pulse generation schemes as applied to a soft x-ray free electron laser. The first scheme, recently proposed by Saldin et al., makes use of a laser pulse consisting of only a few optical cycles to give an energy chirp to a short section of an electron bunch and tapers the main radiator undulator in order to compensate the chirped region. The second scheme investigated takes a low-charge, high brightness electron bunch and compresses it to ˜1fs in order to operate in the so-called “single-spike” regime. We perform start-to-end simulations of both these schemes, assess the sensitivity of each scheme to realistic jitter sources, and provide a direct comparison of the respective strengths and drawbacks.

  14. Comparison of short pulse generation schemes for a soft x-ray free electron laser

    Directory of Open Access Journals (Sweden)

    I. P. S. Martin

    2011-03-01

    Full Text Available In this paper we study the performance of two complementary short pulse generation schemes as applied to a soft x-ray free electron laser. The first scheme, recently proposed by Saldin et al., makes use of a laser pulse consisting of only a few optical cycles to give an energy chirp to a short section of an electron bunch and tapers the main radiator undulator in order to compensate the chirped region. The second scheme investigated takes a low-charge, high brightness electron bunch and compresses it to ∼1  fs in order to operate in the so-called “single-spike” regime. We perform start-to-end simulations of both these schemes, assess the sensitivity of each scheme to realistic jitter sources, and provide a direct comparison of the respective strengths and drawbacks.

  15. Quantum-mechanical analysis of pulse reconstruction for a narrow bandwidth attosecond x-ray pulse

    Institute of Scientific and Technical Information of China (English)

    Ge Yu-Cheng

    2009-01-01

    The photoelectron energy spectra(PESs)excited by narrow bandwidth attosecond x-ray pulses in the presence of a few-cycle laser are quantum-mechanically calculated.Transfer equations are used to reconstruct the detailed temporal structure of an attosecond x-ray pulse directly from a measured PES.Theoretical analysis shows that the temporal uncertainties of the pulse reconstruction depend on the x-ray bandwidth.The procedure of pulse reconstruction is direct and simple without making any previous pulse assumption,data fitting analysis and time-resolved measurement of PESs.The temporal measurement range is half of a laser optical cycle.

  16. Liquid explosions induced by X-ray laser pulses

    Science.gov (United States)

    Stan, Claudiu A.; Milathianaki, Despina; Laksmono, Hartawan; Sierra, Raymond G.; McQueen, Trevor A.; Messerschmidt, Marc; Williams, Garth J.; Koglin, Jason E.; Lane, Thomas J.; Hayes, Matt J.; Guillet, Serge A. H.; Liang, Mengning; Aquila, Andrew L.; Willmott, Philip R.; Robinson, Joseph S.; Gumerlock, Karl L.; Botha, Sabine; Nass, Karol; Schlichting, Ilme; Shoeman, Robert L.; Stone, Howard A.; Boutet, Sébastien

    2016-10-01

    Explosions are spectacular and intriguing phenomena that expose the dynamics of matter under extreme conditions. We investigated, using time-resolved imaging, explosions induced by ultraintense X-ray laser pulses in water drops and jets. Our observations revealed an explosive vaporization followed by high-velocity interacting flows of liquid and vapour, and by the generation of shock trains in the liquid jets. These flows are different from those previously observed in laser ablation, owing to a simpler spatial pattern of X-ray absorption. We show that the explosion dynamics in our experiments is consistent with a redistribution of absorbed energy, mediated by a pressure or shock wave in the liquid, and we model the effects of explosions, including their adverse impact on X-ray laser experiments. X-ray laser explosions have predictable dynamics that may prove useful for controlling the state of pure liquids over broad energy scales and timescales, and for triggering pressure-sensitive molecular dynamics in solutions.

  17. Imaging Macromolecules with X-ray laser pulses

    CERN Document Server

    CERN. Geneva

    2017-01-01

    The short wavelength of X-rays allows us to resolve atoms, but in practise for biological materials the achievable resolution is limited by the destruction of the sample by the radiation that forms the image.  For over 100 years, the workaround to this problem of radiation damage has been to average signals from repeating copies of the object arranged in a large crystal.  It is now possible to overcome damage limits by using intense X-ray pulses that vaporise the sample, but which are short enough in duration to freeze any motion of the sample on the atomic scale.  With the advent of X-ray FELs we have been able to confirm this principle, and are now applying it to overcoming a major bottleneck for protein crystallography, which is the need for large well-diffracting crystals.  The intense pulses also open up opportunities to help solve the crystallographic phase problem.  In particular we have found that commonly-occurring disordered crystals that are usually not ...

  18. Single 100-terawatt attosecond X-ray light pulse generation

    CERN Document Server

    Xu, X R; Zhang, Y X; Lu, H Y; Zhang, H; Dromey, B; Zhu, S P; Zhou, C T; Zepf, M; He, X T

    2016-01-01

    The birth of attosecond light sources is expected to inspire a breakthrough in ultrafast optics, which may extend human real-time measurement and control techniques into atomic-scale electronic dynamics. For applications, it is essential to obtain a single attosecond pulse of high intensity, large photon energy and short duration. Here we show that single 100-terawatt attosecond X-ray light pulse with intensity ${1\\times10^{21}}\\textrm{W}/\\textrm{cm}^{{ 2}}$ and duration ${7.9} \\textrm{as}$ can be produced by intense laser irradiation on a capacitor-nanofoil target composed of two separate nanofoils. In the interaction, a strong electrostatic potential develops between two nanofoils, which drags electrons out of the second foil and piles them up in vacuum, forming an ultradense relativistic electron nanobunch. This nanobunch exists in only half a laser cycle and smears out in others, resulting in coherent synchrotron emission of a single pulse. Such an unprecedentedly giant attosecond X-ray pulse may bring us...

  19. Liquid explosions induced by X-ray laser pulses

    Science.gov (United States)

    Stan, Claudiu; Laksmono, Hartawan; Sierra, Raymond; McQueen, Trevor; Milathianaki, Despina; Koglin, Jason; Lane, Thomas; Messerschmidt, Marc; Williams, Garth; Hayes, Matt; Guillet, Serge; Botha, Sabine; Nass, Karol; Schlichting, Ilme; Shoeman, Robert; Stone, Howard; Boutet, Sébastien

    2015-11-01

    Sudden generation and release of enough energy to vaporize matter are encountered in systems that range from supernovae explosions and asteroid impacts to applications in fusion energy generation, materials processing, and laser surgery. Understanding these strong explosions is important to both fundamental science and technical applications. We studied a new type of microexplosion, induced by absorption of X-ray pulses from a free-electron laser in micron-sized drops and jets of water. These explosions are related to, but different from, those observed in experiments performed with optical lasers. Unlike explosions caused by optical lasers, X-ray laser explosions produce symmetric expansion patterns that are simpler to rationalize. The release of energy initially concentrated in a small region inside drops and jets leads to ballistic vapor flow and inertial liquid flow. The kinematics of these flows indicates that the conversion of the energy deposited by X-rays into flow has a scaling that is similar to the one encountered in shock waves.

  20. 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.

  1. In situ X-ray diffraction during pulsed laser deposition

    Energy Technology Data Exchange (ETDEWEB)

    Vonk, Vedran [Max-Planck-Institute for Metals Research, Stuttgart (Germany); Huijben, Mark [University of California, Berkeley (United States); Driessen, Kurt; Rijnders, Guus; Blank, Dave; Harkema, Sybolt [University of Twente, Enschede (Netherlands); Graafsma, Heinz [Deutsches Elektronen- Synchrotron, Hamburg (Germany)

    2007-07-01

    The use of in situ X-ray diffraction for the study of thin film growth enables in a straightforward way to derive the atomic structure, because the kinematical scattering approximation holds. Here we present the results of studying the heteroepitaxial growth by Pulsed Laser Deposition of complex oxides such as the High-T c superconductor YBa{sub 2}Cu{sub 3}O{sub 7-x} and the insulator LaAlO{sub 3} on SrTiO{sub 3}(001) substrates. A special sample chamber has been constructed to be used with synchrotron X-rays. Detailed pictures of the growth kinetics and of the atomic interface structure at deposition conditions result from fitting quantitatively both the intensity growth oscillations and the crystal truncation rods. The growth of the complex oxide thin films presented here is characterized by substantial interlayer-mass transport and large deviations from the bulk room-temperature atomic structure. The results show the effects of the interplay between formation and diffusion energies on the processes of nucleation and kinetics during heteroepitaxial growth.

  2. Processing of X-ray Microcalorimeter Data with Pulse Shape Variation using Principal Component Analysis

    CERN Document Server

    Yan, Daikang; Gades, Lisa; Jacobsen, Chris; Madden, Timothy; Miceli, Antonino

    2016-01-01

    We present a method using principal component analysis (PCA) to process x-ray pulses with severe shape variation where traditional optimal filter methods fail. We demonstrate that PCA is able to noise-filter and extract energy information from x-ray pulses despite their different shapes. We apply this method to a dataset from an x-ray thermal kinetic inductance detector which has severe pulse shape variation arising from position-dependent absorption.

  3. Ultrashort hard x-ray pulses generated by 90 degrees Thomson scattering

    Energy Technology Data Exchange (ETDEWEB)

    Chin, A.H. [Univ. of California, Berkeley, CA (United States); Schoenlein, R.W.; Glover, T.E. [Ernest Orlando Lawrence Berkeley National Lab., CA (United States)] [and others

    1997-04-01

    Ultrashort x-ray pulses permit observation of fast structural dynamics in a variety of condensed matter systems. The authors have generated 300 femtosecond, 30 keV x-ray pulses by 90 degrees Thomson scattering between femtosecond laser pulses and relativistic electrons. The x-ray and laser pulses are synchronized on a femtosecond time scale, an important prerequisite for ultrafast pump-probe spectroscopy. Analysis of the x-ray beam properties also allows for electron bunch characterization on a femtosecond time scale.

  4. On the response of electronic personal dosimeters in constant potential and pulsed X-ray beams

    Energy Technology Data Exchange (ETDEWEB)

    Guimaraes, Margarete C.; Silva, Teogenes; Silva, Claudete R.E., E-mail: margaretecristinag@gmail.com [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil); Oliveira, Paulo Marcio C. de [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Departamento de Anatomia e Imagem

    2015-07-01

    Electronic personal dosimeters (EPDs) based on solid state detectors have widely been used but some deficiencies in their response in pulsed radiation beams have been reported. Nowadays, there is not an international standard for pulsed X-ray beams for calibration or type testing of dosimeters. Irradiation conditions for testing the response of EPDs in both the constant potential and pulsed X-ray beams were established in CDTN. Three different types of EPDs were tested in different conditions in similar ISO and IEC X-ray qualities. Results stressed the need of performing additional checks before using EPDs in constant potential or pulsed X-rays. (author)

  5. On the response of electronic personal dosimeters in constant potential and pulsed x- ray beams

    Science.gov (United States)

    Guimarães, M. C.; Silva, C. R. E.; Oliveira, P. M. C.; da Silva, T. A.

    2016-07-01

    Electronic personal dosimeters (EPDs) based on solid state detectors have widely been used but some deficiencies in their response in pulsed radiation beams have been reported. Nowadays, there is not an international standard for pulsed x-ray beams for calibration or type testing of dosimeters. Irradiation conditions for testing the response of EPDs in both the constant potential and pulsed x-ray beams were established in CDTN. Three different types of EPDs were tested in different conditions in similar ISO and IEC x-ray qualities. Results stressed the need of performing additional checks before using EPDs in constant potential or pulsed x-rays.

  6. The Radiation Dose Determination of the Pulsed X-ray Source

    Science.gov (United States)

    Miloichikova, I.; Stuchebrov, S.; Zhaksybayeva, G.; Wagner, A.

    2014-10-01

    In this paper the radiation dose measurement technique of the pulsed X-ray source RAP-160-5 is described. The dose rate measurement results from the pulsed X-ray beams at the different distance between the pulsed X-ray source focus and the detector obtained with the help of the thermoluminescent detectors DTL-02, the universal dosimeter UNIDOS E equipped with the plane-parallel ionization chamber type 23342, the dosimeter-radiometer DKS-96 and the radiation dosimeter AT 1123 are demonstrated. The recommendations for the dosimetry measurements of the pulsed X-ray generator RAP-160-5 under different radiation conditions are proposed.

  7. Correlations between pulsed X-ray flux and radio arrival time in the Vela pulsar

    CERN Document Server

    Lommen, A N; Gwinn, C; Arzoumanian, Z; Harding, A; Strickman, M S; Dodson, R; McCulloch, P; Moffett, D

    2007-01-01

    We report the results of simultaneous observations of the Vela pulsar in X-rays and radio from the RXTE satellite and the Mount Pleasant Radio Observatory in Tasmania. We sought correlations between the Vela's X-ray and radio flux densities and radio arrival times on a pulse by pulse basis. We found significantly higher flux density in Vela's main X-ray peak during radio pulses that arrived early. This excess flux shifts to the 'trough' following the 2nd X-ray peak during radio pulses that arrive later. We suggest that the mechanism producing the radio pulses is intimately connected to the mechanism producing X-rays. Current models using resonant absorption in the outer magnetosphere as a cause of the radio emission, and less directly of the X-ray emission, are explored as a possible explanation for the correlation.

  8. 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.

  9. Time dependence of X-ray polarizability of a crystal induced by an intense femtosecond X-ray pulse

    Directory of Open Access Journals (Sweden)

    A. Leonov

    2014-11-01

    Full Text Available The time evolution of the electron density and the resulting time dependence of Fourier components of the X-ray polarizability of a crystal irradiated by highly intense femtosecond pulses of an X-ray free-electron laser (XFEL is investigated theoretically on the basis of rate equations for bound electrons and the Boltzmann equation for the kinetics of the unbound electron gas. The photoionization, Auger process, electron-impact ionization, electron–electron scattering and three-body recombination have been implemented in the system of rate equations. An algorithm for the numerical solution of the rate equations was simplified by incorporating analytical expressions for the cross sections of all the electron configurations in ions within the framework of the effective charge model. Using this approach, the time dependence of the inner shell populations during the time of XFEL pulse propagation through the crystal was evaluated for photon energies between 4 and 12 keV and a pulse width of 40 fs considering a flux of 1012 photons pulse−1 (focusing on a spot size of ∼1 µm. This flux corresponds to a fluence ranging between 0.8 and 2.4 mJ µm−2. The time evolution of the X-ray polarizability caused by the change of the atomic scattering factor during the pulse propagation is numerically analyzed for the case of a silicon crystal. The time-integrated polarizability drops dramatically if the fluence of the X-ray pulse exceeds 1.6 mJ µm−2.

  10. Single-pulse x-ray diffraction using polycapillary optics for in situ dynamic diffraction.

    Science.gov (United States)

    Maddox, B R; Akin, M C; Teruya, A; Hunt, D; Hahn, D; Cradick, J; Morgan, D V

    2016-08-01

    Diagnostic use of single-pulse x-ray diffraction (XRD) at pulsed power facilities can be challenging due to factors such as the high flux and brightness requirements for diffraction and the geometric constraints of experimental platforms. By necessity, the x-ray source is usually positioned very close, within a few inches of the sample. On dynamic compression platforms, this puts the x-ray source in the debris field. We coupled x-ray polycapillary optics to a single-shot needle-and-washer x-ray diode source using a laser-based alignment scheme to obtain high-quality x-ray diffraction using a single 16 ns x-ray pulse with the source >1 m from the sample. The system was tested on a Mo sample in reflection geometry using 17 keV x-rays from a Mo anode. We also identified an anode conditioning effect that increased the x-ray intensity by 180%. Quantitative measurements of the x-ray focal spot produced by the polycapillary yielded a total x-ray flux on the sample of 3.3 ± 0.5 × 10(7) molybdenum Kα photons.

  11. Single shot diffraction of picosecond 8.7-keV x-ray pulses

    OpenAIRE

    F. H. O’Shea; O. Williams; Andonian, G.; Barber, S; Sakai, Y.; Rosenzweig, J. B.; Pogorelsky, I.; Fedurin, M.; K. Kusche; Yakimenko, V.

    2012-01-01

    We demonstrate multiphoton, single shot diffraction images of x rays produced by inverse Compton scattering a high-power CO_{2} laser from a relativistic electron beam, creating a pulse of 8.7 keV x rays. The tightly focused, relatively high peak brightness electron beam and high photon density from the 2 J CO_{2} laser yielded 6×10^{7} x-ray photons over the full opening angle in a single shot. Single shot x-ray diffraction is performed by passing the x rays though a vertical slit and on to ...

  12. Production of transform-limited X-ray pulses through self-seeding at the European X-ray FEL

    CERN Document Server

    Geloni, Gianluca; Saldin, Evgeni

    2011-01-01

    An important goal for any advanced X-ray FEL is an option for providing Fourier-limited X-ray pulses. In this way, no monochromator is needed in the experimental hall. Self-seeding is a promising approach to significantly narrow the SASE bandwidth to produce nearly transform-limited pulses. These are important for many experiments including 3D diffraction imaging. We discuss the implementation of a single-crystal self-seeding scheme in the hard X-ray lines of the European XFEL. For this facility, transform-limited pulses are particularly valuable since they naturally support the extraction of more FEL power than at saturation by exploiting tapering in the tunable-gap baseline undulators. Tapering consists of a stepwise change of the undulator gap from segment to segment. Based on start-to-end simulations dealing with the up-to-date parameters of the European XFEL, we show that the FEL power reaches about 400 GW, or one order of magnitude higher power than the SASE saturation level (20 GW). This analysis indic...

  13. Stopping Narrow-Band X-Ray Pulses in Nuclear Media

    Science.gov (United States)

    Kong, Xiangjin; Pálffy, Adriana

    2016-05-01

    A control mechanism for stopping x-ray pulses in resonant nuclear media is investigated theoretically. We show that narrow-band x-ray pulses can be mapped and stored as nuclear coherence in a thin-film planar x-ray cavity with an embedded 57Fe nuclear layer. The pulse is nearly resonant to the 14.4 keV Mössbauer transition in the 57Fe nuclei. The role of the control field is played here by a hyperfine magnetic field which induces interference effects reminiscent of electromagnetically induced transparency. We show that, by switching off the control magnetic field, a narrow-band x-ray pulse can be completely stored in the cavity for approximately 100 ns. Additional manipulation of the external magnetic field can lead to both group velocity and phase control of the pulse in the x-ray cavity sample.

  14. Production of quasi ellipsoidal laser pulses for next generation high brightness photoinjectors

    Energy Technology Data Exchange (ETDEWEB)

    Rublack, T., E-mail: Tino.Rublack@desy.de [DESY, Zeuthen (Germany); Good, J.; Khojoyan, M.; Krasilnikov, M.; Stephan, F. [DESY, Zeuthen (Germany); Hartl, I.; Schreiber, S. [DESY, Hamburg (Germany); Andrianov, A.; Gacheva, E.; Khazanov, E.; Mironov, S.; Potemkin, A.; Zelenogorskii, V.V. [IAP/RAS, Nizhny Novgorod (Russian Federation); Syresin, E. [JINR, Dubna (Russian Federation)

    2016-09-01

    The use of high brightness electron beams in Free Electron Laser (FEL) applications is of increasing importance. One of the most promising methods to generate such beams is the usage of shaped photocathode laser pulses. It has already demonstrated that temporal and transverse flat-top laser pulses can produce very low emittance beams [1]. Nevertheless, based on beam simulations further improvements can be achieved using quasi-ellipsoidal laser pulses, e.g. 30% reduction in transverse projected emittance at 1 nC bunch charge. In a collaboration between DESY, the Institute of Applied Physics of the Russian Academy of Science (IAP RAS) in Nizhny Novgorod and the Joint Institute of Nuclear Research (JINR) in Dubna such a laser system capable of producing trains of laser pulses with a quasi-ellipsoidal distribution, has been developed. The prototype of the system was installed at the Photo Injector Test facility at DESY in Zeuthen (PITZ) and is currently in the commissioning phase. In the following, the laser system will be introduced, the procedure of pulse shaping will be described and the last experimental results will be shown.

  15. Optically Levitated Targets as a Source for High Brightness X-rays and a Platform for Mass-Limited Laser-interaction Experiments

    Science.gov (United States)

    Giltrap, Samuel; Stuart, Nick; Robinson, Tim; Armstrong, Chris; Hicks, George; Eardley, Sam; Gumbrell, Ed; Smith, Roland

    2016-10-01

    Here we report on the development of an optical levitation based x-ray and proton source, motivated by the requirement for a debris free, high spatial resolution, and low EMP source for x-ray radiography and proton production. Research at Imperial College has led to the development of a feedback controlled optical levitation trap which is capable of holding both solid (Glass beads) and liquid (silicon based oil) micro-targets ( 3-10um). The optical levitation trap has been successfully fielded in a high-intensity laser interaction experiment at Imperial College London and at the Vulcan Petawatt Laser system at the Rutherford Appleton Laboratory (RAL). Here we report on the results from that RAL run including; an x-ray source size of 10-15um with very good spherical symmetry when compared to wire targets, secondly very low EMP signal from isolated levitated targets (9 times less RF signal than a comparable wire target). At Imperial College we were also able to record an x-ray energy spectrum which produced an electron temperature of 0.48KeV, and performed interferometry of a shock evolving into a blast wave off an optically levitated droplet which allowed us to infer the electron density within the shock front.

  16. Temporal and Spectral Resolved Measurement of Soft X-ray From Ultrashort Pulse Laser Produced Plasma

    Institute of Scientific and Technical Information of China (English)

    W.Theobald; L.Veisz; H.Schwoerer; R.Sauerbrey; X.Z.Tang

    2001-01-01

    Ultrashort laser pulse produced plasmas are powerful sources of incoherent XUV/soft X-ray radiation and have important applications range from microscopy to lithography. Adding a prepulse is one possible way to enhance soft X-ray emission. The experiment is performed on the Jena 10 TW laser system in IOQ, Germany. The main purpose is to measure the time-resolved soft X-ray spectrum, and study how a prepulse play an important role and enhance the X-ray emission as well as and pulse duration. We clarified the temporal behavior of X-ray emission from quartz plasma produced by intensive femtosecond 800 nm laser pulse, and obtained a quantitative pictures of the

  17. Filming Femtosecond Molecular Movies with X-ray Pulses

    DEFF Research Database (Denmark)

    Kjær, Kasper Skov

    This thesis describes the investigation of time-resolved phenomena using X-ray techniques, and in particular the new possibilities and challenges arising from the application of these techniques on the femtosecond time-scale. The thesis will review the processes following laser excitation...... of molecular species in solution, describing the interplay between electronic and structural dynamics, as well as the role of the solvent. This will be followed by an introduction of the three X-ray techniques used in this work, and it will be shown how the application of these techniques in a laser pump / X...... yielded by (and the practical challenges connected to) their simultaneous implementation in a single experiment. Finally, the experimental results of a signicant set of laser pump / X-ray probe experiments will be presented and discussed in order to gauge the applicability of these techniques as tools...

  18. Pile-up corrections in laser-driven pulsed x-ray sources

    CERN Document Server

    Hernández, Guillermo

    2016-01-01

    A formalism for treating the pile-up produced in laser-driven pulsed x-ray sources has been developed. It allows the direct use of x-ray spectroscopy without artificially decreasing the number of counts in the detector. The influence of the pile-up on the overestimation of temperature parameters is shown up.

  19. Production of transform-limited X-ray pulses through self-seeding at the European X-ray FEL

    Energy Technology Data Exchange (ETDEWEB)

    Geloni, Gianluca [European XFEL GmbH, Hamburg (Germany); Kocharyan, Vitali; Saldin, Evgeni [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2011-09-15

    An important goal for any advanced X-ray FEL is an option for providing Fourier-limited X-ray pulses. In this way, no monochromator is needed in the experimental hall. Self-seeding is a promising approach to significantly narrow the SASE bandwidth to produce nearly transform-limited pulses. These are important for many experiments including 3D diffraction imaging.We discuss the implementation of a single-crystal self-seeding scheme in the hard X-ray lines of the European XFEL. For this facility, transform-limited pulses are particularly valuable since they naturally support the extraction of more FEL power than at saturation by exploiting tapering in the tunable-gap baseline undulators. Tapering consists of a stepwise change of the undulator gap from segment to segment. Based on start-to-end simulations dealing with the up-to-date parameters of the European XFEL, we show that the FEL power reaches about 400 GW, or one order of magnitude higher power than the SASE saturation level (20 GW). This analysis indicates that our self-seeding scheme is not significantly affected by non-ideal electron phase-space distribution, and yields about the same performance as in the case for an electron beam with ideal parameters. The self-seeding scheme with a single crystal monochromator is extremely compact (about 5 m long), and cost estimations are low enough to consider adding it to the European XFEL capabilities from the very beginning of the operation phase. (orig.)

  20. Stopping x-ray pulses in a thin-film cavity via electromagnetically induced transparency

    CERN Document Server

    Kong, Xiangjin

    2015-01-01

    Stopping light via an electromagnetically induced transparency setup for x-ray pulses in a thin film planar x-ray cavity is investigated theoretically. The pulse is nearly resonant to the 14.4 keV M\\"ossbauer transition in $^{57}\\mathrm{Fe}$, with one nm-thin layer of the latter embedded in the thin-film x-ray cavity. Via a moderate hyperfine magnetic field which takes over the role of the control field, electromagnetically induced transparency and slowing down of the x-ray pulse occurs in the cavity setup. We show that by switching off the control magnetic field, a narrowband x-ray pulse can be completely stored in the cavity for approx. hundred ns. Coherent storage occurs in this scenario by imprinting the x-ray field onto nuclear coherences in a controllable and robust manner. Additional manipulation of the external magnetic field can lead to both group velocity and phase control of the pulse in the x-ray cavity sample.

  1. Single shot diffraction of picosecond 8.7-keV x-ray pulses

    Directory of Open Access Journals (Sweden)

    F. H. O’Shea

    2012-02-01

    Full Text Available We demonstrate multiphoton, single shot diffraction images of x rays produced by inverse Compton scattering a high-power CO_{2} laser from a relativistic electron beam, creating a pulse of 8.7 keV x rays. The tightly focused, relatively high peak brightness electron beam and high photon density from the 2 J CO_{2} laser yielded 6×10^{7} x-ray photons over the full opening angle in a single shot. Single shot x-ray diffraction is performed by passing the x rays though a vertical slit and on to a flat silicon (111 crystal. 10^{2} diffracted photons were detected. The spectrum of the detected x rays is compared to simulation. The diffraction and detection of 10^{2} x rays is a key step to a more efficient time resolved diagnostic in which the number of observed x rays might reach 10^{4}; enabling a unique, flexible x-ray source as a sub-ps resolution diagnostic for studying the evolution of chemical reactions, lattice deformation and melting, and magnetism.

  2. Generation of attosecond soft x-ray pulses in a longitudinal space charge amplifier

    Directory of Open Access Journals (Sweden)

    M. Dohlus

    2011-09-01

    Full Text Available A longitudinal space charge amplifier (LSCA, operating in soft x-ray regime, was recently proposed. Such an amplifier consists of a few amplification cascades (focusing channel and chicane and a short radiator undulator in the end. The broadband nature of LSCA supports generation of few-cycle pulses as well as wavelength compression. In this paper we consider an application of these properties of LSCA for generation of attosecond x-ray pulses. It is shown that a compact and cheap addition to the soft x-ray free-electron laser facility FLASH would allow one to generate 60 attosecond (FWHM long x-ray pulses with the peak power at the 100 MW level and a contrast above 98%.

  3. Generation of attosecond soft X-ray pulses in a longitudinal space charge amplifier

    Energy Technology Data Exchange (ETDEWEB)

    Dohlus, M.; Schneidmiller, E.A.; Yurkov, M.V. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2011-03-15

    A longitudinal space charge amplifier (LSCA), operating in soft X-ray regime, was recently proposed. Such an amplifier consists of a few amplification cascades (focusing channel and chicane) and a short radiator undulator in the end. Broadband nature of LSCA supports generation of few-cycle pulses as well as wavelength compression. In this paper we consider an application of these properties of LSCA for generation of attosecond X-ray pulses. It is shown that a compact and cheap addition to the soft X-ray free electron laser facility FLASH would allow to generate 60 attosecond (FWHM) long X-ray pulses with the peak power at 100 MW level and a contrast above 98%. (orig.)

  4. Normal Auger processes with ultrashort x-ray pulses in neon

    Science.gov (United States)

    Sullivan, Raymond; Jia, Junteng; Vázquez-Mayagoitia, Álvaro; Picón, Antonio

    2016-10-01

    Modern x-ray sources enable the production of coherent x-ray pulses with a pulse duration in the same order as the characteristic lifetimes of core-hole states of atoms and molecules. These pulses enable the manipulation of the core-hole population during Auger-decay processes, modifying the line shape of the electron spectra. In this work, we present a theoretical model to study those effects in neon. We identify effects in the Auger-electron-photoelectron coincidence spectrum due to the duration and intensity of the pulses. The normal Auger line shape is recovered in Auger-electron spectra integrated over all photoelectron energies.

  5. Generating Picosecond X-Ray Pulses with Beam Manipulation in Synchrotron Light Sources

    CERN Document Server

    Guo, Weiming; Harkay, Katherine C; Sajaev, Vadim; Yang Bing Xin

    2005-01-01

    The length of x-ray pulses generated by storage ring light sources is usually tens of picoseconds. For example, the value is 40 ps rms at the Advanced Photon Source (APS). Methods of x-ray pulse compression are of great interest at the APS. One possible method, per Zholents et al., is to tilt the electron bunch with deflecting rf cavities.* Alternately, we found that the electron bunch can develop a tilt after application of a vertical kick in the presence of nonzero chromaticity. After slicing, the x-ray pulse length is determined by the tilt angle and the vertical beam size. In principal, sub-picosecond pulses can be obtained at APS. To date we have observed 6 ps rms visible light pulses with a streak camera. Efforts are underway to attempt further compression of the x-ray pulse and to increase the brilliance. This method can be easily applied to any storage ring light sources to generate x-ray pulses up to two orders of magnitude shorter than the electron bunch length. In this paper, we will present the th...

  6. Multidimensional resonant nonlinear spectroscopy with coherent broadband x-ray pulses

    Science.gov (United States)

    Bennett, Kochise; Zhang, Yu; Kowalewski, Markus; Hua, Weijie; Mukamel, Shaul

    2016-12-01

    New x-ray free electron laser (XFEL) and high harmonic generation (HHG) light sources are capable of generating short and intense pulses that make x-ray nonlinear spectroscopy possible. Multidimensional spectroscopic techniques, which have long been used in the nuclear magnetic resonance, infrared, and optical regimes to probe the electronic structure and nuclear dynamics of molecules by sequences of short pulses with variable delays, can thus be extended to the attosecond x-ray regime. This opens up the possibility of probing core-electronic structure and couplings, the real-time tracking of impulsively created valence-electronic wavepackets and electronic coherences, and monitoring ultrafast processes such as nonadiabatic electron-nuclear dynamics near conical-intersection crossings. We survey various possible types of multidimensional x-ray spectroscopy techniques and demonstrate the novel information they can provide about molecules.

  7. Mobile x-ray complex based on ironless pulsed betatrons. X-ray complex conception for small-angle tomography

    Science.gov (United States)

    Kozlov, S. G.; Kuropatkin, Yu P.; Nizhegorodtsev, V. I.; Savchenko, K. V.; Selemir, V. D.; Urlin, E. V.; Shamro, O. A.

    2017-05-01

    The conception of creating mobile radiographic complex based on ironless pulsed betatrons is proposed for radiography of dynamic objects having large optical thicknesses. Realization of this conception allows: a) optimizing geometry of the hydrodynamic experiment at the expense of the change of the radiation source and recorder position relatively to the test object, located in the explosion-proof chamber(EPC). Thus, it lets the intensity of the x-ray radiation be increased twice in the recorder plane as compared with available Russian complexes; b) creating an efficient environment protection system at the expense of localization of dangerous explosion products, and a shock wave connected with them; c) significantly decreasing the cost of radiographic complexes, if not building heavy protective casemates and their infrastructure. Instead of them it is possible to use cheap rapidly erected constructions. The mobile radiographic complex is described. Its characteristics, obtained during the testing powering were provided. Thickness of the lead test at 1m from the tantalum target at the limiting energy of the betatron electron beam Elim∼12 MeV( it is determined by the value of a capacitive storage of the pulsed powering system of the electromagnet) was ∼115 mm. Conception of a multibeam complex creation based on ironless pulsed betatrons for small-angle tomography was also considered.

  8. Generation of a high-brightness pulsed positron beam for the Munich scanning positron microscope

    Energy Technology Data Exchange (ETDEWEB)

    Piochacz, Christian

    2009-11-20

    Within the present work the prerequisites for the operation of the Munich scanning positron microscope (SPM) at the high intense neutron induced positron source Munich (NEPOMUC) were established. This was accomplished in two steps: Firstly, a re-moderation device was installed at the positron beam facility NEPOMUC, which enhances the brightness of the positron beam for all connected experiments. The second step was the design, set up and initial operation of the SPM interface for the high efficient conversion of the continuous beam into a bunched beam. The in-pile positron source NEPOMUC creates a positron beam with a diameter of typically 7 mm, a kinetic energy of 1 keV and an energy spread of 50 eV. The NEPOMUC re-moderator generates from this beam a low energy positron beam (20 - 200 eV) with a diameter of less than 2 mm and an energy spread well below 2.5 eV. This was achieved with an excellent total efficiency of 6.55{+-}0.25 %. The re-moderator was not only the rst step to implement the SPM at NEPOMUc, it enables also the operation of the pulsed low energy positron beam system (PLEPS). Within the present work, at this spectrometer rst positron lifetime measurements were performed, which revealed the defect types of an ion irradiated uranium molybdenum alloy. Moreover, the instruments which were already connected to the positron beam facility bene ts considerably of the high brightness enhancement. In the new SPM interface an additional re-moderation stage enhances the brightness of the beam even more and will enable positron lifetime measurements at the SPM with a lateral resolution below 1 {mu}m. The efficiency of the re-moderation process in this second stage was 24.5{+-}4.5 %. In order to convert high efficiently the continuous positron beam into a pulsed beam with a repetition rate of 50 MHz and a pulse duration of less than 50 ps, a sub-harmonic pre-bucher was combined with two sine wave bunchers. Furthermore, the additional re-moderation stage of the

  9. Deconvolving the temporal response of photoelectric x-ray detectors for the diagnosis of pulsed radiations.

    Science.gov (United States)

    Zou, Shiyang; Song, Peng; Guo, Liang; Pei, Wenbing

    2013-09-01

    Based on the conjugate gradient method, a simple algorithm is presented for deconvolving the temporal response of photoelectric x-ray detectors (XRDs) to reconstruct the resolved time-dependent x-ray fluxes. With this algorithm, we have studied the impact of temporal response of XRD on the radiation diagnosis of hohlraum heated by a short intense laser pulse. It is found that the limiting temporal response of XRD not only postpones the rising edge and peak position of x-ray pulses but also smoothes the possible fluctuations of radiation fluxes. Without a proper consideration of the temporal response of XRD, the measured radiation flux can be largely misinterpreted for radiation pulses of a hohlraum heated by short or shaped laser pulses.

  10. 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.

  11. Pulse energy measurement at the hard x-ray laser in Japan

    Energy Technology Data Exchange (ETDEWEB)

    Kato, M.; Tanaka, T.; Saito, N. [National Institute of Advanced Industrial Science and Technology (AIST), NMIJ, Tsukuba 305-8568 (Japan); RIKEN SPring-8 Center, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148 (Japan); Kurosawa, T. [National Institute of Advanced Industrial Science and Technology (AIST), NMIJ, Tsukuba 305-8568 (Japan); Richter, M. [RIKEN SPring-8 Center, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148 (Japan); Physikalisch-Technische Bundesanstalt (PTB), Abbestrasse 2-12, D-10587 Berlin (Germany); Sorokin, A. A. [RIKEN SPring-8 Center, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148 (Japan); Deutsches Elektronen-Synchrotron (DESY), Notkestrasse 85, D-22603 Hamburg (Germany); Ioffe Physico-Technical Institute, RAS, Polytekhnicheskaya 26, 194021 St. Petersburg (Russian Federation); Tiedtke, K. [RIKEN SPring-8 Center, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148 (Japan); Deutsches Elektronen-Synchrotron (DESY), Notkestrasse 85, D-22603 Hamburg (Germany); Kudo, T.; Yabashi, M. [RIKEN SPring-8 Center, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148 (Japan); Japan Synchrotron Radiation Research Institute, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan); Tono, K. [Japan Synchrotron Radiation Research Institute, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan); Ishikawa, T. [RIKEN SPring-8 Center, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148 (Japan)

    2012-07-09

    The pulse energies of a free electron laser have accurately been measured in the hard x-ray spectral range. In the photon energy regime from 4.4 keV to 16.8 keV, pulse energies up to 100 {mu}J were obtained at the hard x-ray laser facility SACLA (SPring-8 Angstrom Compact free-electron LAser). Two independent methods, using a cryogenic radiometer and a gas monitor detector, were applied and agreement within 3.3% was achieved. Based on our validated pulse energy measurement, a SACLA online monitor detector could be calibrated for all future experiments.

  12. Wide-range monitor for pulsed x-ray sources

    Energy Technology Data Exchange (ETDEWEB)

    Kaifer, R.C.; Jenkins, T.E.; Straume, T.

    1981-10-12

    A monitoring instrument based on a high-pressure ionization chamber has been developed that measures average dose rates as low as 0.1 mR/h and responds linearly to short pulses at dose rates up to 1.2 x 10/sup 10/ R/h. Its sensitivity can be remotely changed by a factor of 10/sup 4/, to enable accurate measurement of both background radiation and very high intensities such as can be expected from accelerator beam-spills. The instrument's detector-electrometer pulse response was measured using a dose-calibrated field-emission accelerator having a 30-ns pulse width.

  13. 25 Tesla pulsed-high-magnetic-field system for soft X-ray spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Hayashi, M., E-mail: mhaya@imr.tohoku.ac.jp [Institute for Materials Research, Tohoku University, Sendai 980-8577 (Japan); Narumi, Y.; Nojiri, H. [Institute for Materials Research, Tohoku University, Sendai 980-8577 (Japan); Nakamura, T.; Hirono, T.; Kinoshita, T. [JASRI/SPring-8, Sayo, Hyogo 679-5198 (Japan); Kodama, K. [Department of Mechanical Engineering, Nara National College of Technology, Nara 639-1080 (Japan); Kindo, K. [Institute for Solid State Physics, University of Tokyo, Kashiwa 277-8581 (Japan)

    2011-04-15

    Research highlights: {yields} We have developed a 25 T pulsed magnetic field system for soft X-ray MCD. {yields} The new capacitor bank can generate a field in the bipolar mode. {yields} We measured the Soft X-ray MCD of paramagnetic Gd{sub 2}O{sub 3} up to 25 T. - Abstract: We have developed a 25 T pulsed high magnetic field system for soft X-ray Magnetic Circular Dichroism: XMCD. The ultra-high vacuum chamber with a pulse magnet coil is installed. By using a newly developed bipolar capacitor bank, the XMCD of paramagnetic Gd{sub 2}O{sub 3} at the M{sub 5} and the M{sub 4} edges was clearly observed at low temperatures. The present system is capable of measuring XMCD of field induced moments in various compounds including paramagnets and antiferromagnets.

  14. Obtaining attosecond x-ray pulses using a self-amplified spontaneous emission free electron laser

    Directory of Open Access Journals (Sweden)

    A. A. Zholents

    2005-05-01

    Full Text Available We describe a technique for the generation of a solitary attosecond x-ray pulse in a free-electron laser (FEL, via a process of self-amplified spontaneous emission. In this method, electrons experience an energy modulation upon interacting with laser pulses having a duration of a few cycles within single-period wiggler magnets. Two consecutive modulation sections, followed by compression in a dispersive section, are used to obtain a single, subfemtosecond spike in the electron peak current. This region of the electron beam experiences an enhanced growth rate for FEL amplification. After propagation through a long undulator, this current spike emits a ∼250   attosecond x-ray pulse whose intensity dominates the x-ray emission from the rest of the electron bunch.

  15. A new soft x-ray pulse height analysis array in the HL-2A tokamak

    Science.gov (United States)

    Zhang, Y. P.; Liu, Yi; Yang, J. W.; Song, X. Y.; Liao, M.; Li, X.; Yuan, G. L.; Yang, Q. W.; Duan, X. R.; Pan, C. H.

    2009-12-01

    A new soft x-ray pulse height analysis (PHA) array including nine independent subsystems, on basis of a nonconventional software multichannel analysis system and a silicon drift detector (SDD) linear array consisting of nine high performance SDD detectors, has been developed in the HL-2A tokamak. The use of SDD has greatly improved the measurement accuracy and the spatiotemporal resolutions of the soft x-ray PHA system. Since the ratio of peak to background counts obtained from the SDD PHA system is very high, p /b≧3000, the soft x-ray spectra measured by the SDD PHA system can approximatively be regarded as electron velocity distribution. The electron velocity distribution can be well derived in the pure ohmic and auxiliary heating discharges. The performance of the new soft x-ray PHA array and the first experimental results with some discussions are presented.

  16. Explosive Device for Generation of Pulsed Fluxes of Soft X-Ray Radiation

    Science.gov (United States)

    Selemir, V. D.; Demidov, V. A.; Ivanovsky, A. V.; Yermolovich, V. F.; Kornilov, V. G.; Chelpanov, V. I.; Kazakov, S. A.; Vlasov, Y. V.; Orlov, A. P.

    2004-11-01

    The concept and realization of the explosive electrophysical device EMIR to generate soft x-ray radiation pulses are described. EMIR is based on the development of VNIIEF technologies in high-power flux compression generators, and on transforming systems based on lines with distributed parameters and current opening switches. Vacuum lines with magnetic insulation or water coaxial lines are considered for transmission of the energy pulses to the load. Transformation of magnetic energy to kinetic energy, thermalization and soft x-ray radiation are performed in a z-pinch with a double liner system.

  17. Discovery of X-Ray Emission from the Crab Pulsar at Pulse Minimum

    Science.gov (United States)

    Tennant, Allyn F.; Becker, Werner; Juda, Michael; Elsner, Ronald F.; Kolodziejczak, Jeffery J.; Murray, Stephen S.; ODell, Stephen L.; Paerels, Frits; Swartz, Douglas A.

    2001-01-01

    The Chandra X-Ray Observatory observed the Crab pulsar using the Low-Energy Transmission Grating with the High-Resolution Camera. Time-resolved zeroth-order images reveal that the pulsar emits X-rays at all pulse phases. Analysis of the flux at minimum - most likely non-thermal in origin - places an upper limit (T(sub infinity) neutron star. In addition, analysis of the pulse profile establishes that the error in the Chandra-determined absolute time is quite small, -0.2 +/- 0.1 ms.

  18. A two-stage series diode for intense large-area moderate pulsed X rays production

    Science.gov (United States)

    Lai, Dingguo; Qiu, Mengtong; Xu, Qifu; Su, Zhaofeng; Li, Mo; Ren, Shuqing; Huang, Zhongliang

    2017-01-01

    This paper presents a method for moderate pulsed X rays produced by a series diode, which can be driven by high voltage pulse to generate intense large-area uniform sub-100-keV X rays. A two stage series diode was designed for Flash-II accelerator and experimentally investigated. A compact support system of floating converter/cathode was invented, the extra cathode is floating electrically and mechanically, by withdrawing three support pins several milliseconds before a diode electrical pulse. A double ring cathode was developed to improve the surface electric field and emission stability. The cathode radii and diode separation gap were optimized to enhance the uniformity of X rays and coincidence of the two diode voltages based on the simulation and theoretical calculation. The experimental results show that the two stage series diode can work stably under 700 kV and 300 kA, the average energy of X rays is 86 keV, and the dose is about 296 rad(Si) over 615 cm2 area with uniformity 2:1 at 5 cm from the last converter. Compared with the single diode, the average X rays' energy reduces from 132 keV to 88 keV, and the proportion of sub-100-keV photons increases from 39% to 69%.

  19. Development of single frame X-ray framing camera for pulsed plasma experiments

    Indian Academy of Sciences (India)

    J Upadhyay; J A Chakera; C P Navathe; P A Naik; A S Joshi; P D Gupta

    2006-10-01

    A single-frame X-ray framing camera has been set up for fast imaging of X-ray emissions from pulsed plasma sources. It consists of two parts, viz. an X-ray pin-hole camera using an open-ended microchannel plate (MCP) detector coupled to a CCD camera, and a high voltage short duration gate pulse for the MCP. The camera uses a 10-m pin-hole aperture for imaging on the MCP detector with a magnification of 6X. The high voltage pulser circuit generates a pulse of variable duration from 5 to 30 ns (at 70% of peak amplitude) with variable amplitude from 800 V to 1·25 kV, and is triggered through a laser pulse synchronized with the event to be recorded. The performance of the system has been checked by recording X-ray emission from a laser-produced copper plasma. A reduction factor of ∼6·5 is seen in the dark current contribution as the MCP gate pulse is decreased from 250s to 5 ns duration.

  20. Ways to produce and measure atto- and femtosecond soft X-ray pulses

    Institute of Scientific and Technical Information of China (English)

    GE YuCheng

    2007-01-01

    The ways to produce and measure atto- and femtosecond soft X-ray pulses are reported. The laser phase relation of high-order harmonic generation (HHG) shows two different radiation energy distributions in time (or laser phase) domain. These energy-phase relations are helpful for realizing the dynamic processes of HHG. Two presented parameterized formulas can be used to calculate the durations of the energy distributions with a bandwidth of the pulse. These formulas are useful in calculating and simulating pulses transports and interactions with mediums. The time structures of atto- and femtosecond soft X-ray pulses can be directly measured with photoelectron spectrum transfer equations and the related laser phase determination methods without any previous pulse shape and the instantaneous frequency assumptions. These equations and methods can be used to evaluate and improve the technical parameters of the ultra-short X-ray sources. They have wide measurement ranges and high time resolutions, which may enable ultra-fast measurements to reach metrological precisions, and lead to a new tide of scientific researches in physics, chemistry, biochemistry, etc. The application of attoand femtosecond X-rays as well as the theoretical and technical problems in measurements are briefly discussed.

  1. Reflection of femtosecond pulses from soft X-ray free-electron laser by periodical multilayers

    Energy Technology Data Exchange (ETDEWEB)

    Ksenzov, D.; Grigorian, S.; Pietsch, U. [Faculty of Physics, University of Siegen (Germany); Hendel, S.; Bienert, F.; Sacher, M.D.; Heinzmann, U. [Faculty of Physics, University of Bielefeld (Germany)

    2009-08-15

    Recent experiments on a soft X-ray free-electron laser (FEL) source (FLASH in Hamburg) have shown that multilayers (MLs) can be used as optical elements for highly intense X-ray irradiation. An effort to find most appropriate MLs has to consider the femtosecond time structure and the particular photon energy of the FEL. In this paper we have analysed the time response of 'low absorbing' MLs (e.g. such as La/B{sub 4}C) as a function of the number of periods. Interaction of a pulse train of Gaussian shaped sub-pulses using a realistic ML grown by electron-beam evaporation technique has been analysed in the soft-X-ray range. The structural parameters of the MLs were obtained by reflectivity measurements at BESSY II and subsequent profile fittings. (Abstract Copyright [2009], Wiley Periodicals, Inc.)

  2. Generation of stable subfemtosecond hard x-ray pulses with optimized nonlinear bunch compression

    Directory of Open Access Journals (Sweden)

    Senlin Huang

    2014-12-01

    Full Text Available In this paper, we propose a simple scheme that leverages existing x-ray free-electron laser hardware to produce stable single-spike, subfemtosecond x-ray pulses. By optimizing a high-harmonic radio-frequency linearizer to achieve nonlinear compression of a low-charge (20 pC electron beam, we obtain a sharp current profile possessing a few-femtosecond full width at half maximum temporal duration. A reverse undulator taper is applied to enable lasing only within the current spike, where longitudinal space charge forces induce an electron beam time-energy chirp. Simulations based on the Linac Coherent Light Source parameters show that stable single-spike x-ray pulses with a duration less than 200 attoseconds can be obtained.

  3. Generation of bright isolated attosecond soft X-ray pulses driven by multicycle midinfrared lasers.

    Science.gov (United States)

    Chen, Ming-Chang; Mancuso, Christopher; Hernández-García, Carlos; Dollar, Franklin; Galloway, Ben; Popmintchev, Dimitar; Huang, Pei-Chi; Walker, Barry; Plaja, Luis; Jaroń-Becker, Agnieszka A; Becker, Andreas; Murnane, Margaret M; Kapteyn, Henry C; Popmintchev, Tenio

    2014-06-10

    High harmonic generation driven by femtosecond lasers makes it possible to capture the fastest dynamics in molecules and materials. However, to date the shortest subfemtosecond (attosecond, 10(-18) s) pulses have been produced only in the extreme UV region of the spectrum below 100 eV, which limits the range of materials and molecular systems that can be explored. Here we experimentally demonstrate a remarkable convergence of physics: when midinfrared lasers are used to drive high harmonic generation, the conditions for optimal bright, soft X-ray generation naturally coincide with the generation of isolated attosecond pulses. The temporal window over which phase matching occurs shrinks rapidly with increasing driving laser wavelength, to the extent that bright isolated attosecond pulses are the norm for 2-µm driving lasers. Harnessing this realization, we experimentally demonstrate the generation of isolated soft X-ray attosecond pulses at photon energies up to 180 eV for the first time, to our knowledge, with a transform limit of 35 attoseconds (as), and a predicted linear chirp of 300 as. Most surprisingly, advanced theory shows that in contrast with as pulse generation in the extreme UV, long-duration, 10-cycle, driving laser pulses are required to generate isolated soft X-ray bursts efficiently, to mitigate group velocity walk-off between the laser and the X-ray fields that otherwise limit the conversion efficiency. Our work demonstrates a clear and straightforward approach for robustly generating bright isolated attosecond pulses of electromagnetic radiation throughout the soft X-ray region of the spectrum.

  4. Communication: The electronic structure of matter probed with a single femtosecond hard x-ray pulse

    Directory of Open Access Journals (Sweden)

    J. Szlachetko

    2014-03-01

    Full Text Available Physical, biological, and chemical transformations are initiated by changes in the electronic configuration of the species involved. These electronic changes occur on the timescales of attoseconds (10−18 s to femtoseconds (10−15 s and drive all subsequent electronic reorganization as the system moves to a new equilibrium or quasi-equilibrium state. The ability to detect the dynamics of these electronic changes is crucial for understanding the potential energy surfaces upon which chemical and biological reactions take place. Here, we report on the determination of the electronic structure of matter using a single self-seeded femtosecond x-ray pulse from the Linac Coherent Light Source hard x-ray free electron laser. By measuring the high energy resolution off-resonant spectrum (HEROS, we were able to obtain information about the electronic density of states with a single femtosecond x-ray pulse. We show that the unoccupied electronic states of the scattering atom may be determined on a shot-to-shot basis and that the measured spectral shape is independent of the large intensity fluctuations of the incoming x-ray beam. Moreover, we demonstrate the chemical sensitivity and single-shot capability and limitations of HEROS, which enables the technique to track the electronic structural dynamics in matter on femtosecond time scales, making it an ideal probe technique for time-resolved X-ray experiments.

  5. 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.

  6. Analyses of the short pulse laser pumped transient collisional excited X-ray lasers

    Energy Technology Data Exchange (ETDEWEB)

    Sasaki, A.; Utsumi, T.; Moribayashi, K.; Zhidkov, A.; Kado, M.; Tanaka, M.; Hasegawa, N.; Kawachi, T. [Japan Atomic Energy Research Inst., Osaka (Japan). Advanced Photon Research Center

    2001-07-01

    The soft X-ray gain of the transient collisional excited (TCE) Ni-like Ag laser is investigated using the plasma hydrodynamics and atomic kinetics codes. The gain is calculated for a plasma produced from two 100ps laser irradiated solid target to show qualitative agreement with the experiment. The calculation shows significant improvement of the gain using a thin foil target pumped by two short laser pulses, because of a better coupling of the pump laser energy into the gain region of the plasma. The codes will provide performance prediction as well as optimization of the experimental studies of the TCE X-ray lasers. (orig.)

  7. Laser and Pulsed Power Electron Density Imaging Through Talbot-Lau X-ray Deflectometry

    Science.gov (United States)

    Valdivia Leiva, Maria Pia; Stutman, Dan; Stoeckl, Christian; Mileham, Chad; Begischev, Ildar; Theobald, Wolfgang; Bromage, Jake; Regan, Sean; Klein, Salee; Muñoz-Cordovez, Gonzalo; Vescovi, Milenko; Valenzuela-Villaseca, Vicente; Veloso, Felipe

    2016-10-01

    A Talbot-Lau X-ray Deflectometer was deployed using laser driven and x-pinch x-ray backlighters. The Talbot-Lau X-ray Deflectometer is an ideal electron density diagnostic for High Energy Density plasmas with the potential to simultaneously deliver x-ray refraction, attenuation, elemental composition, and scatter information from a single image with source limited resolution. Grating survival and electron density mapping was demonstrated for 10-29 J, 8-30 ps laser pulses using Cu foil targets at the Multi-TeraWatt facility. An areal electron density of 0.050 g/cm2 was obtained at the center of a fluoro-nylon fiber of 300 mm diameter with a source FWHM of 80 µm and resolution of 50 µm. Grating survival and Moiré pattern formation was demonstrated using a Cu x-pinch plasma of FWHM 27 µm, driven by the 350 kA, 350 ns Llampudken pulsed power generator. These results closely match simulations and laboratory results. It was demonstrated that the technique can detect both sharp and smooth density gradients in the range of 2x1023 to 2x1025 cm-3, thus allowing implementation of the electron density technique as a HED plasma diagnostic in both laser and pulsed power experiments U.S. DoE/NNSA and DE-NA0002955.

  8. Pulsar X-Ray and Gamma-Ray Pulse Profiles Constraint on Obliquity and Observer Angles

    CERN Document Server

    Harding, A K; Harding, Alice K.; Muslimov, Alexander G.

    1998-01-01

    We model the thermal X-ray profiles of Geminga, Vela and PSR 0656+14, which have also been detected as gamma-ray pulsars, to constrain the phase space of obliquity and observer angles required to reproduce the observed X-ray pulsed fractions and pulse widths. These geometrical constraints derived from the X-ray light curves are explored for various assumptions about surface temperature distribution and flux anisotropy caused by the magnetized atmosphere. We include curved spacetime effects on photon trajectories and magnetic field. The observed gamma-ray pulse profiles are double peaked with phase separations of 0.4 - 0.5 between the peaks. Assuming that the gamma-ray profiles are due to emission in a hollow cone centered on the magnetic pole, we derive the constraints on the phase space of obliquity and observer angles, for different gamma-ray beam sizes, required to produce the observed gamma-ray peak phase separations. We compare the constraints from the X-ray emission to those derived from the observed ga...

  9. Soft x-ray generation in gases with an ultrashort pulse laser

    Energy Technology Data Exchange (ETDEWEB)

    Ditmire, Todd Raymond [Univ. of California, Davis, CA (United States)

    1996-01-08

    An experimental investigation of soft x-ray production resulting from the interaction of intense near infra-red laser radiation with gases is presented in this thesis. Specifically, soft x-ray generation through high order harmonic generation or exploiting intense inverse bremsstrahlung heating is examined. Most of these studies are conducted with femtosecond, terawatt class Cr:LiSrAlF6 (LiSAF) laser, though results derived from studies with other laser systems are presented as well. The majority of this work is devoted to experimental investigations, however, theoretical and computational models are developed to interpret the data. These studies are motivated by the possibility of utilizing the physics of intense laser/matter interactions as a potential compact source of bright x-rays. Consequently, the thrust of many of the experiments conducted is aimed at characterizing the x-rays produced for possible use in applications. In general, the studies of this manuscript fall into three categories. First, a unique 130 fs, 8 TW laser that is based on chirped pulse amplification, is described, and its performance is evaluated. The generation of x-rays through high order harmonics is then discussed with emphasis on characterizing and optimizing harmonic generation. Finally, the generation of strong, incoherent x-ray radiation by the intense irradiation of large (>1,000 atom) clusters in gas jets, is explored. The physics of laser energy absorption by clusters illuminated with intensities of 1015 to 1017 W/cm2 is considered in detail. X-ray spectroscopy of the hot plasmas that result from the irradiation of the clusters is conducted, and energy transport and kinetics issues in these plasmas are discussed.

  10. Multilayer zone plates for X-ray focusing fabricated by pulsed laser deposition

    Energy Technology Data Exchange (ETDEWEB)

    Doering, Florian; Eberl, Christian; Liese, Tobias; Krebs, Hans-Ulrich [Institut fuer Materialphysik, University of Goettingen, Friedrich-Hund-Platz 1, 37077 Goettingen (Germany)

    2012-07-01

    X-ray microscopy in the soft and hard regime is a highly useful technique for biological and materials sciences, polymer research, colloidal science and even earth science. One alternative approach for two-dimensional x-ray focusing is to prepare non-periodic multilayer structures. They can be designed in zone plate geometry by depositing high quality non-periodic multilayers on wires according to the Fresnel zone plate law. For this, ZrO{sub 2}/Ti and W/Si multilayers with high optical contrast in the soft and hard x-ray region, respectively, were pulsed laser deposited (PLD) at 248 nm. In this contribution, the growth of multilayers on flat and curved surfaces (studied by electron microscopy after focused ion beam preparation) is compared, and the fabrication steps of different zone plate structures are presented.

  11. A high-field pulsed magnet system for x-ray scattering studies in Voigt geometry

    CERN Document Server

    Islam, Zahirul; Ruff, Jacob P C; Das, Ritesh K; Trakhtenberg, Emil; Nojiri, Hiroyuki; Narumi, Yasuo; Canfield, Paul C

    2011-01-01

    We present a new pulsed-magnet system that enables x-ray single-crystal diffraction in addition to powder and spectroscopic studies in Voigt geometry. The apparatus consists of a large-bore solenoid, cooled by liquid nitrogen. A second independent closed-cycle cryostat is used for cooling samples near liquid helium temperatures. Pulsed magnetic fields up to ~30 T with a minimum of ~6 ms in total duration are generated by discharging a 40 kJ capacitor bank into the magnet coil. The unique characteristic of this instrument is the preservation of maximum scattering angle (~23.6 deg.) through the magnet bore by virtue of a novel double-funnel insert. This instrument would facilitate x-ray diffraction and spectroscopic studies that are impractical, if not impossible, to perform using conventional split-pair magnets and offers a practical solution for preserving optical access in future higher-field pulsed magnets.

  12. Developments of compact pulsed-power system toward X-ray sources

    Directory of Open Access Journals (Sweden)

    Miyamoto Takuya

    2013-11-01

    Full Text Available In order to generate X-rays from X-pinch, the peak current and current-rising time required are estimated to be 100 kA and 100 ns, respectively. To obtain these parameters, we developed a pulsed-power system, which consists of a parallelized pulse-forming network (PFN. The 20 PFN modules of the system were driven at a charging voltage of 20 kV by a thin copper wire of load resistance. The results showed that the current and current-rising time are 18 kA and 107 ns, respectively. The wire/plasma temperature is 6.9 eV. The pulsed-power system is expected to generate X-rays from X-pinch by the proposed system. This can be achieved by raising the voltage and increasing the number of PFN modules.

  13. Generation of large-bandwidth x-ray free-electron-laser pulses

    Directory of Open Access Journals (Sweden)

    Angela Saa Hernandez

    2016-09-01

    Full Text Available X-ray free-electron lasers (XFELs are modern research tools in disciplines such as biology, material science, chemistry, and physics. Besides the standard operation that aims at minimizing the bandwidth of the produced XFEL radiation, there is a strong scientific demand to produce large-bandwidth XFEL pulses for several applications such as nanocrystallography, stimulated Raman spectroscopy, and multiwavelength anomalous diffraction. We present a self-consistent method that maximizes the XFEL pulse bandwidth by systematically maximizing the energy chirp of the electron beam at the undulator entrance. This is achieved by optimizing the compression scheme and the electron distribution at the source in an iterative back-and-forward tracking. Start-to-end numerical simulations show that a relative bandwidth of 3.25% full-width can be achieved for the hard x-ray pulses in the SwissFEL case.

  14. X-ray emission from a nanosecond-pulse discharge in an inhomogeneous electric field at atmospheric pressure

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Cheng; Shao Tao; Ren Chengyan; Zhang Dongdong [Institute of Electrical Engineering, Chinese Academy of Sciences, Beijing 100190 (China); Key Laboratory of Power Electronics and Electric Drive, Chinese Academy of Sciences, Beijing 100190 (China); Tarasenko, Victor; Kostyrya, Igor D. [Institute of High Current Electronics, Russian Academy of Science, Tomsk 634055 (Russian Federation); Ma Hao [Institute of Electrical Engineering, Chinese Academy of Sciences, Beijing 100190 (China); Yan Ping [Institute of Electrical Engineering, Chinese Academy of Sciences, Beijing 100190 (China); Key Laboratory of Power Electronics and Electric Drive, Chinese Academy of Sciences, Beijing 100190 (China); State Key Laboratory of Electrical Insulation and Power Equipment, Xi' an Jiaotong University, Xi' an 710049 (China)

    2012-12-15

    This paper describes experimental studies of the dependence of the X-ray intensity on the anode material in nanosecond high-voltage discharges. The discharges were generated by two nanosecond-pulse generators in atmospheric air with a highly inhomogeneous electric field by a tube-plate gap. The output pulse of the first generator (repetitive pulse generator) has a rise time of about 15 ns and a full width at half maximum of 30-40 ns. The output of the second generator (single pulse generator) has a rise time of about 0.3 ns and a full width at half maximum of 1 ns. The electrical characteristics and the X-ray emission of nanosecond-pulse discharge in atmospheric air are studied by the measurement of voltage-current waveforms, discharge images, X-ray count and dose. Our experimental results showed that the anode material rarely affects electrical characteristics, but it can significantly affect the X-ray density. Comparing the density of X-rays, it was shown that the highest x-rays density occurred in the diffuse discharge in repetitive pulse mode, then the spark discharge with a small air gap, and then the corona discharge with a large air gap, in which the X-ray density was the lowest. Therefore, it could be confirmed that the bremsstrahlung at the anode contributes to the X-ray emission from nanosecond-pulse discharges.

  15. Compact stacking of diode lasers for pulsed light sources of high brightness.

    Science.gov (United States)

    Alahautala, Taito; Lassila, Erkki; Hernberg, Rolf

    2004-07-20

    A compact stacking architecture for high-power diode-laser arrays is proposed and compared with traditional stacks. The objective of compact stacking is to achieve high brightness values without the use of microlenses. The calculated brightness for a compact stack is over 300 W mm(-2) sr(-1), which is approximately 40 times higher than that of a traditional stack made of similar laser emitters. Even higher brightness values of over 600 W mm(-2) sr(-1) were reached in practice. A laser head was manufactured in which the light from several compact laser stacks could be fiber coupled or the light could be transformed to a highly uniform beam.

  16. 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.

  17. Coherence Properties of Individual Femtosecond Pulses of an X-ray Free-Electron Laser

    Energy Technology Data Exchange (ETDEWEB)

    Vartanyants, I.A.; /DESY /Moscow Phys. Eng. Inst.; Singer, A.; Mancuso, A.P.; Yefanov, O.M.; /DESY; Sakdinawat, A.; Liu, Y.; Bang, E.; /UC, Berkeley; Williams, G.J.; /SLAC; Cadenazzi, G.; Abbey, B.; /Melbourne U.; Sinn, H.; /European XFEL, Hamburg; Attwood, D.; /UC, Berkeley; Nugent, K.A.; /Melbourne U.; Weckert, E.; /DESY; Wang, T.; Zhu, D.; Wu, B.; Graves, C.; Scherz, A.; Turner, J.J.; Schlotter, W.F.; /SLAC /LERMA, Ivry /Zurich, ETH /LBL, Berkeley /ANL, APS /Argonne /SLAC /LLNL, Livermore /Latrobe U. /SLAC /SLAC /European XFEL, Hamburg /SLAC /Hamburg U.

    2012-06-06

    Measurements of the spatial and temporal coherence of single, femtosecond x-ray pulses generated by the first hard x-ray free-electron laser, the Linac Coherent Light Source, are presented. Single-shot measurements were performed at 780 eV x-ray photon energy using apertures containing double pinholes in 'diffract-and-destroy' mode. We determined a coherence length of 17 {micro}m in the vertical direction, which is approximately the size of the focused Linac Coherent Light Source beam in the same direction. The analysis of the diffraction patterns produced by the pinholes with the largest separation yields an estimate of the temporal coherence time of 0.55 fs. We find that the total degree of transverse coherence is 56% and that the x-ray pulses are adequately described by two transverse coherent modes in each direction. This leads us to the conclusion that 78% of the total power is contained in the dominant mode.

  18. Coherence Properties of Individual Femtosecond Pulses of an X-ray Free-Electron Laser

    Energy Technology Data Exchange (ETDEWEB)

    Vartanyants, I.A.; /DESY /Moscow Phys. Eng. Inst.; Singer, A.; Mancuso, A.P.; Yefanov, O.M.; /DESY; Sakdinawat, A.; Liu, Y.; Bang, E.; /UC, Berkeley; Williams, G.J.; /SLAC; Cadenazzi, G.; Abbey, B.; /Melbourne U.; Sinn, H.; /European XFEL, Hamburg; Attwood, D.; /UC, Berkeley; Nugent, K.A.; /Melbourne U.; Weckert, E.; /DESY; Wang, T.; Zhu, D.; Wu, B.; Graves, C.; Scherz, A.; Turner, J.J.; Schlotter, W.F.; /SLAC /LERMA, Ivry /Zurich, ETH /LBL, Berkeley /ANL, APS /Argonne /SLAC /LLNL, Livermore /Latrobe U. /SLAC /SLAC /European XFEL, Hamburg /SLAC /Hamburg U.

    2012-06-06

    Measurements of the spatial and temporal coherence of single, femtosecond x-ray pulses generated by the first hard x-ray free-electron laser, the Linac Coherent Light Source, are presented. Single-shot measurements were performed at 780 eV x-ray photon energy using apertures containing double pinholes in 'diffract-and-destroy' mode. We determined a coherence length of 17 {micro}m in the vertical direction, which is approximately the size of the focused Linac Coherent Light Source beam in the same direction. The analysis of the diffraction patterns produced by the pinholes with the largest separation yields an estimate of the temporal coherence time of 0.55 fs. We find that the total degree of transverse coherence is 56% and that the x-ray pulses are adequately described by two transverse coherent modes in each direction. This leads us to the conclusion that 78% of the total power is contained in the dominant mode.

  19. Femtosecond x-ray free electron laser pulse duration measurement from spectral correlation function

    Directory of Open Access Journals (Sweden)

    A. A. Lutman

    2012-03-01

    Full Text Available We present a novel method for measuring the duration of femtosecond x-ray pulses from self-amplified spontaneous emission free electron lasers by performing statistical analysis in the spectral domain. Analytical expressions of the spectral correlation function were derived in the linear regime to extract both the pulse duration and the spectrometer resolution. Numerical simulations confirmed that the method can be also used in the nonlinear regime. The method was demonstrated experimentally at the Linac Coherent Light Source by measuring pulse durations down to 13 fs FWHM.

  20. Single-molecule imaging with longer X-ray laser pulses

    Directory of Open Access Journals (Sweden)

    Andrew V. Martin

    2015-11-01

    Full Text Available During the last five years, serial femtosecond crystallography using X-ray laser pulses has been developed into a powerful technique for determining the atomic structures of protein molecules from micrometre- and sub-micrometre-sized crystals. One of the key reasons for this success is the `self-gating' pulse effect, whereby the X-ray laser pulses do not need to outrun all radiation damage processes. Instead, X-ray-induced damage terminates the Bragg diffraction prior to the pulse completing its passage through the sample, as if the Bragg diffraction were generated by a shorter pulse of equal intensity. As a result, serial femtosecond crystallography does not need to be performed with pulses as short as 5–10 fs, but can succeed for pulses 50–100 fs in duration. It is shown here that a similar gating effect applies to single-molecule diffraction with respect to spatially uncorrelated damage processes like ionization and ion diffusion. The effect is clearly seen in calculations of the diffraction contrast, by calculating the diffraction of the average structure separately to the diffraction from statistical fluctuations of the structure due to damage (`damage noise'. The results suggest that sub-nanometre single-molecule imaging with 30–50 fs pulses, like those produced at currently operating facilities, should not yet be ruled out. The theory presented opens up new experimental avenues to measure the impact of damage on single-particle diffraction, which is needed to test damage models and to identify optimal imaging conditions.

  1. Energy Resolution Effects on Plasma Electron Temperature Measurements by Soft X-Ray Pulse-Height-Analysis

    Institute of Scientific and Technical Information of China (English)

    SHI Yue-Jiang; WAN Bao-Nian

    2001-01-01

    The soft x-ray pulse-height-analysis technique is a conventional tool to measure electron temperature on tokamaks.The soft x-ray spectra distortion due to the energy resolution of the detector will affect the temperature andimpurity concentration determination. To evaluate these effects, distorted spectra as functions of energy resolutionare derived by numerical modelling. The results show that the low-energy resolution detector can fit for the largesized tokamak soft x-ray spectra.

  2. Ablation of a nanostructured metal surface by ultrashort X-ray pulses

    Energy Technology Data Exchange (ETDEWEB)

    Rosandi, Yudi, E-mail: rosandi@geophys.unpad.ac.id [Department of Physics, Universitas Padjadjaran, Jatinangor, Sumedang 45363 (Indonesia); Fachbereich Physik und Forschungszentrum OPTIMAS, Universität Kaiserslautern, Erwin-Schrödinger-Straße, D-67663 Kaiserslautern (Germany); Urbassek, Herbert M., E-mail: urbassek@rhrk.uni-kl.de [Fachbereich Physik und Forschungszentrum OPTIMAS, Universität Kaiserslautern, Erwin-Schrödinger-Straße, D-67663 Kaiserslautern (Germany)

    2014-07-01

    Using molecular-dynamics simulation, we study the interaction of an ultrashort X-ray pulse with an Al surface. The surface has a periodic grating structure consisting of alternating ridges of height 80 nm and width 80 nm, separated by trenches of width 160 nm. After irradiation with an ultrashort (0.2 ps) X-ray pulse with a fluence above the ablation threshold we observe that the ridges first disintegrate into a foamy mixture of melt and gas bubbles, which grow faster than those in the trenches. Due to the interference of tensile pressure build-up below the ridges and the trenches, the material does not spall. At the concave edges, jets are emitted with velocities of around 1000 m/s, which may ultimately lead to the creation of finer surface structures.

  3. Ultrashort x-ray pulse generation by electron beam slicing in storage rings

    Directory of Open Access Journals (Sweden)

    A. He

    2014-04-01

    Full Text Available We propose a new method to generate ultrashort x-ray pulses using focused short low energy (∼20  MeV electron bunches to create short slices of electrons from the circulating electron bunches in a synchrotron radiation storage ring. When a low energy electron bunch crosses from the top of a high energy storage ring electron bunch, its Coulomb force will kick a short slice from the core of the storage ring electron bunch. The separated slices, when passing through an undulator, will radiate ultrashort x-ray pulses at about 160 fs. We discuss the advantages, challenges, and provide data which confirm the feasibility of this new method.

  4. Characterisation of flash X-ray source generated by Kali-1000 Pulse Power System

    Science.gov (United States)

    Satyanarayana, N.; Durga Prasada Rao, A.; Mittal, K. C.

    2016-02-01

    The electron beam-driven Rod Pinch Diode (RPD) is presently fielded on KALI-1000 Pulse Power System at Bhabha Atomic Research Centre, Visakhapatnam and is a leading candidate for future flash X-ray radiographic sources. The diode is capable of producing less than 2-mm radiation spot sizes and greater than 350 milli rads of dose measured at 1 m from the X-ray source. KALI-1000 Pulse Power Source is capable of delivering up to 600 kV using a Tesla Transformer with Demineralized Insulated Transmission Line (DITL), the diode typically operates between 250-330 kV . Since the radiation dose has a power-law dependence on diode voltage, this limits the dose production on KALI-1000 system. Radiation dose with angular variation is measured using thermoluminescent detectors (TLD's) and the X-ray spot size is measured using pin hole arrangement with image plate (IP) to obtain the time-integrated source profile as well as a time-resolved spot diagnostic. An X-ray pinhole camera was used to pick out where the energetic e-beam connects to the anode. Ideally the diode should function such that the radiation is emitted from the tip. The camera was mounted perpendicular to the machine's axis to view the radiation from the tip. Comparison of the spot sizes of the X-ray sources obtained by the pin hole and rolled edge arrangements was carried and results obtained by both the techniques are with in ± 10% of the average values.

  5. Propagation and scattering of high-intensity X-ray pulses in dense atomic gases and plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Weninger, Clemens

    2015-10-15

    Nonlinear spectroscopy in the X-ray domain is a promising technique to explore the dynamics of elementary excitations in matter. X-rays provide an element specificity that allows them to target individual chemical elements, making them a great tool to study complex molecules. The recent advancement of X-ray free electron lasers (XFELs) allows to investigate non-linear processes in the X-ray domain for the first time. XFELs provide short femtosecond X-ray pulses with peak powers that exceed previous generation synchrotron X-ray sources by more than nine orders of magnitude. This thesis focuses on the theoretical description of stimulated emission processes in the X-ray regime in atomic gases. These processes form the basis for more complex schemes in molecules and provide a proof of principle for nonlinear X-ray spectroscopy. The thesis also includes results from two experimental campaigns at the Linac Coherent Light Source and presents the first experimental demonstration of stimulated X-ray Raman scattering. Focusing an X-ray free electron laser beam into an elongated neon gas target generates an intense stimulated X-ray emission beam in forward direction. If the incoming X-rays have a photon energy above the neon K edge, they can efficiently photo-ionize 1s electrons and generate short-lived core excited states. The core-excited states decay mostly via Auger decay but have a small probability to emit a spontaneous X-ray photon. The spontaneous emission emitted in forward direction can stimulate X-ray emission along the medium and generate a highly directional and intense X-ray laser pulse. If the photon energy of the incoming X-rays however is below the ionization edge in the region of the pre-edge resonance the incoming X-rays can be inelastically scattered. This spontaneous X-ray Raman scattering process has a very low probability, but the spontaneously scattered photons in the beginning of the medium can stimulate Raman scattering along the medium. The

  6. A new technique to generate 100 GW-level attosecond X-ray pulses from the X-ray SASE FELs

    CERN Document Server

    Saldin, E L; Yurkov, M V

    2004-01-01

    We propose a scheme for generation of single 100 GW 300-as pulse in the X-ray free electron laser with the use of a few cycles optical pulse from Ti:sapphire laser system. Femtosecond optical pulse interacts with the electron beam in the two-period undulator resonant to 800 nm wavelength and produces energy modulation within a slice of the electron bunch. Following the energy modulator the electron beam enters the first part of the baseline gap-adjustable X-ray undulator and produces SASE radiation with 100 MW-level power. Due to energy modulation the frequency is correlated to the longitudinal position within the few-cycle-driven slice of the SASE radiation pulse. The largest frequency offset corresponds to a single-spike pulse in the time domain which is confined to one half-oscillation period near the central peak electron energy. After the first undulator the electron beam is guided through a magnetic delay which we use to position the X-ray spike with the largest frequency offset at the "fresh" part of t...

  7. Generation of intense attosecond x-ray pulses using ultraviolet laser induced microbunching in electron beams

    Directory of Open Access Journals (Sweden)

    D. Xiang

    2009-06-01

    Full Text Available We propose a scheme that combines the echo-enabled harmonic generation technique with the bunch compression and allows one to generate harmonic numbers of a few hundred in a microbunched beam through up-conversion of the frequency of an ultraviolet seed laser. A few-cycle intense laser is used to generate the required energy chirp in the beam for bunch compression and for selection of an attosecond x-ray pulse. Sending this beam through a short undulator results in an intense isolated attosecond x-ray pulse. Using a representative realistic set of parameters, we show that 1 nm x-ray pulse with peak power of a few hundred MW and duration as short as 20 attoseconds (FWHM can be generated from a 200 nm ultraviolet seed laser. The proposed scheme may enable the study of electronic dynamics with a resolution beyond the atomic unit of time (∼24 attoseconds and may open a new regime of ultrafast sciences.

  8. Generating picosecond x-ray pulses in synchrotron light sources using dipole kickers

    Directory of Open Access Journals (Sweden)

    W. Guo

    2007-02-01

    Full Text Available The duration of the x-ray pulse generated at a synchrotron light source is typically tens of picoseconds. Shorter pulses are highly desired by the users. In electron storage rings, the vertical beam size is usually orders of magnitude less than the bunch length due to radiation damping; therefore, a shorter pulse can be obtained by slitting the vertically tilted bunch. Zholents proposed tilting the bunch using rf deflection. We found that tilted bunches can also be generated by a dipole magnet kick. A vertical tilt is developed after the kick in the presence of nonzero chromaticity. The tilt was successfully observed and a 4.2-ps pulse was obtained from a 27-ps electron bunch at the Advanced Photon Source. Based on this principle, we propose a short-pulse generation scheme that produces picosecond x-ray pulses at a repetition rate of 1–2 kHz, which can be used for pump-probe experiments.

  9. Sliding Mode Pulsed Averaging IC Drivers for High Brightness Light Emitting Diodes

    Energy Technology Data Exchange (ETDEWEB)

    Dr. Anatoly Shteynberg, PhD

    2006-08-17

    This project developed new Light Emitting Diode (LED) driver ICs associated with specific (uniquely operated) switching power supplies that optimize performance for High Brightness LEDs (HB-LEDs). The drivers utilize a digital control core with a newly developed nonlinear, hysteretic/sliding mode controller with mixed-signal processing. The drivers are flexible enough to allow both traditional microprocessor interface as well as other options such as “on the fly” adjustment of color and brightness. Some other unique features of the newly developed drivers include • AC Power Factor Correction; • High power efficiency; • Substantially fewer external components should be required, leading to substantial reduction of Bill of Materials (BOM). Thus, the LED drivers developed in this research : optimize LED performance by increasing power efficiency and power factor. Perhaps more remarkably, the LED drivers provide this improved performance at substantially reduced costs compared to the present LED power electronic driver circuits. Since one of the barriers to market penetration for HB-LEDs (in particular “white” light LEDs) is cost/lumen, this research makes important contributions in helping the advancement of SSL consumer acceptance and usage.

  10. Reproducible radiation-damage processes in proteins irradiated by intense x-ray pulses

    Science.gov (United States)

    Hau-Riege, Stefan P.; Bennion, Brian J.

    2015-02-01

    X-ray free-electron lasers have enabled femtosecond protein nanocrystallography, a novel method to determine the structure of proteins. It allows time-resolved imaging of nanocrystals that are too small for conventional crystallography. The short pulse duration helps in overcoming the detrimental effects of radiation damage because x rays are scattered before the sample has been significantly altered. It has been suggested that, fortuitously, the diffraction process self-terminates abruptly once radiation damage destroys the crystalline order. Our calculations show that high-intensity x-ray pulses indeed trigger a cascade of damage processes in ferredoxin crystals, a particular metalloprotein of interest. However, we found that the damage process is initially not completely random. Correlations exist among the protein monomers, so that Bragg diffraction still occurs in the damaged crystals, despite significant atomic displacements. Our results show that the damage process is reproducible to a certain degree, which is potentially beneficial for the orientation step in single-molecule imaging.

  11. Generation of Attosecond X-Ray Pulse through Coherent Relativistic Nonlinear Thomson Scattering

    CERN Document Server

    Lee, K; Jeong, Y U; Lee, B C; Park, S H

    2005-01-01

    In contrast to some recent experimental results, which state that the Nonlinear Thomson Scattered (NTS) radiation is incoherent, a coherent condition under which the scattered radiation of an incident laser pulse by a bunch of electrons can be coherently superposed has been investigated. The Coherent Relativistic Nonlinear Thomson Scattered (C-RNTS) radiation makes it possible utilizing the ultra-short pulse nature of NTS radiation with a bunch of electrons, such as plasma or electron beams. A numerical simulation shows that a 25 attosecond X-ray pulse can be generated by irradiating an ultra-intense laser pulse of 4x10(19) W/cm2 on an ultra-thin solid target of 50 nm thickness, which is commercially available. The coherent condition can be easily extended to an electron beam from accelerators. Different from the solid target, much narrower electron beam is required for the generation of an attosecond pulse. Instead, this condition could be applied for the generation of intense Compton scattered X-rays with a...

  12. X-ray-boosted photoionization for the measurement of an intense laser pulse

    Institute of Scientific and Technical Information of China (English)

    Ge Yu-Cheng; He Hai-Ping

    2013-01-01

    Investigations show that X-ray-boosted photoionization (XBP) has the following advantages for in-situ measurements of ultrahigh laser intensity Ⅰ and field envelope F(t) (time t,pulse duration τL,carrier-envelope-phase Φ):accuracy,dynamic range,and rapidness.The calculated XBP spectra resemble inversely proportional functions of the photoelectron momentum shift.The maximum momentump9 and the observable value Q (defined as a double integration of a normalized photoelectron energy spectrum,PES) linearly depend on I1/2 and τL,respectively.Φ and F(t) can be determined from the PES cut-off energy and peak positions.The measurable laser intensity can be up to and over 1018 W/cm2 by using high energy X-rays and highly charged inert gases.

  13. 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.

  14. Measurement of the energy and power radiated by a pulsed blackbody x-ray source

    Directory of Open Access Journals (Sweden)

    H. C. Ives

    2006-11-01

    Full Text Available We have developed a diagnostic system that measures the spectrally integrated (i.e. the total energy and power radiated by a pulsed blackbody x-ray source. The total-energy-and-power (TEP diagnostic system is optimized for blackbody temperatures between 50 and 350 eV. The system can view apertured sources that radiate energies and powers as high as 2 MJ and 200 TW, respectively, and has been successfully tested at 0.84 MJ and 73 TW on the Z pulsed-power accelerator. The TEP system consists of two pinhole arrays, two silicon-diode detectors, and two thin-film nickel bolometers. Each of the two pinhole arrays is paired with a single silicon diode. Each array consists of a 38×38 square array of 10-μm-diameter pinholes in a 50-μm-thick tantalum plate. The arrays achromatically attenuate the x-ray flux by a factor of ∼1800. The use of such arrays for the attenuation of soft x rays was first proposed by Turner and co-workers [Rev. Sci. Instrum. 70, 656 (1999RSINAK0034-674810.1063/1.1149385]. The attenuated flux from each array illuminates its associated diode; the diode’s output current is recorded by a data-acquisition system with 0.6-ns time resolution. The arrays and diodes are located 19 and 24 m from the source, respectively. Because the diodes are designed to have an approximately flat spectral sensitivity, the output current from each diode is proportional to the x-ray power. The nickel bolometers are fielded at a slightly different angle from the array-diode combinations, and view (without pinhole attenuation the same x-ray source. The bolometers measure the total x-ray energy radiated by the source and—on every shot—provide an in situ calibration of the array-diode combinations. Two array-diode pairs and two bolometers are fielded to reduce random uncertainties. An analytic model (which accounts for pinhole-diffraction effects of the sensitivity of an array-diode combination is presented.

  15. Taking X-ray Diffraction to the Limit: Macromolecular Structures from Femtosecond X-ray Pulses and Diffraction Microscopy of Cells with Synchrotron Radiation

    Energy Technology Data Exchange (ETDEWEB)

    Chapman, H N; Miao, J; Kirz, J; Sayre, D; Hodgson, K O

    2003-10-01

    The methodology of X-ray crystallography has recently been successfully extended to the structure determination of non-crystalline specimens. The phase problem was solved by using the oversampling method, which takes advantage of ''continuous'' diffraction pattern from non-crystalline specimens. Here we review the principle of this newly developed technique and discuss the ongoing experiments of imaging non-periodic objects, like cells and cellular structures using coherent and bright X-rays from the 3rd generation synchrotron radiation. In the longer run, the technique may be applied to image single biomolecules by using the anticipated X-ray free electron lasers. Computer simulations have so far demonstrated two important steps: (1) by using an extremely intense femtosecond X-ray pulse, a diffraction pattern can be recorded from a macromolecule before radiation damage manifests itself, and (2) the phase information can be ab initio retrieved from a set of calculated noisy diffraction patterns of single protein molecules.

  16. Prospects for Measuring Neutron-Star Masses and Radii with X-Ray Pulse Profile Modeling

    CERN Document Server

    Psaltis, Dimitrios; Chakrabarty, Deepto

    2013-01-01

    Modeling the amplitudes and shapes of the X-ray pulsations observed from hot, rotating neutron stars provides a direct method for measuring neutron-star properties. This technique constitutes an important part of the science case for the forthcoming NICER and proposed LOFT X-ray missions. In this paper, we determine the number of distinct observables that can be derived from pulse profile modeling and show that using only bolometric pulse profiles is insufficient for breaking the degeneracy between inferred neutron-star radius and mass. However, we also show that for moderately spinning (300-800 Hz) neutron stars, analysis of pulse profiles in two different energy bands provides additional constraints that allow a unique determination of the neutron-star properties. Using the fractional amplitudes of the fundamental and the first harmonic of the pulse profile in addition to the amplitude and phase difference of the spectral color oscillations, we quantify the signal-to-noise ratio necessary to achieve a speci...

  17. "Real-Life" Pulse Flattening on the LLNL Flash X-ray (FXR) Machine

    Energy Technology Data Exchange (ETDEWEB)

    DeHope, W J; Jacob, J S; Kihara, R; Ong, M; Zentler, J M

    2007-06-25

    High-resolution radiography using high-current electron accelerators based on the linear induction accelerator principle requires the linac's final spot on the X-ray target to be millimeter-sized. The requisite final focusing solenoid is adjusted for a specific beam energy at its entrance, hence, temporal variation of entrance beam energy results in a less than optimal time-averaged spot size. The FXR (Flash X-Ray) induction linac facility at Lawrence Livermore National Laboratory will be briefly described with an emphasis on its pulsed power system. In principle, the pulsed Blumleins at the heart of the system output a square pulse when discharged at the peak of their charging waveform so that, with correct cell timing synchronization, the effective beam output into the final focusing solenoid should be optimally flat. We have found that real-life consideration of transmission line and pulse power details in both the injector and accelerator sections of the machine results in significant energy variations in the final beam. We have implemented methods of measurement and analysis that permits this situation to be quantified and improved upon. The improvement will be linked to final beam spot size and enhancement in expected radiographic resolution.

  18. 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...

  19. Toward TW-Level, Hard X-Ray Pulses at LCLS

    Energy Technology Data Exchange (ETDEWEB)

    Fawley, W.M.; Frisch, J.; Huang, Z.; Jiao, Y.; Nuhn, H.-D.; /SLAC; Pellegrini, C.; /SLAC /UCLA; Reiche, S.; /PSI, Villigen; Wu, J,; /SLAC

    2011-12-13

    Coherent diffraction imaging of complex molecules such as proteins requires a large number (e.g., {approx} 10{sup 13}/pulse) of hard X-ray photons within a time scale of {approx} 10 fs or less. This corresponds to a peak power of {approx} 1 TW, much larger than that currently generated by LCLS or other proposed X-ray free electron lasers (FELs). We study the feasibility of producing such pulses using a LCLS-like, low charge electron beam, as will be possible in the LCLS-II upgrade project, employing a configuration beginning with a SASE amplifier, followed by a 'self-seeding' crystal monochromator, and finishing with a long tapered undulator. Our results suggest that TW-level output power at 8.3 keV is possible from a total undulator system length around 200 m. In addition power levels larger than 100 GW are generated at the third harmonic. We present a tapering strategy that extends the original 'resonant particle' formalism by optimizing the transport lattice to maximize optical guiding and enhance net energy extraction. We discuss the transverse and longitudinal coherence properties of the output radiation pulse and the expected output pulse energy sensitivity, both to taper errors and to power fluctuations on the monochromatized SASE seed.

  20. RF Phase Stability and Electron Beam Characterization for the PLEIADES Thomson X-Ray Source

    Energy Technology Data Exchange (ETDEWEB)

    Brown, W J; Hartemann, F V; Tremaine, A M; Springer, P T; Le Sage, G P; Barty, C P J; Rosenzweig, J B; Crane, J K; Cross, R R; Fittinghoff, D N; Gibson, D J; Slaughter, D R; Anderson, S

    2002-10-16

    We report on the performance of an S-band RF photocathode electron gun and accelerator for operation with the PLEIADES Thomson x-ray source at LLNL. To produce picosecond, high brightness x-ray pulses, picosecond timing, terahertz bandwidth diagnostics, and RF phase control are required. Planned optical, RF, x-ray and electron beam measurements to characterize the dependence of electron beam parameters and synchronization on RF phase stability are presented.

  1. Diagnosing Pulsed Power Produced Plasmas with X-ray Thomson Scattering at the Nevada Terawatt Facility

    Science.gov (United States)

    Valenzuela, J. C.; Krauland, C.; Mariscal, D.; Krasheninnikov, I.; Beg, F. N.; Wiewior, P.; Covington, A.; Presura, R.; Ma, T.; Niemann, C.; Mabey, P.; Gregori, G.

    2015-11-01

    We present experimental results on X-ray Thomson scattering (XRTS) at the Nevada Terawatt Facility (NTF) to study current driven plasmas. Using the Leopard laser, ~ 30 J and pulse width of 0.8 ns, we generated He- α emission (4.75 keV) from a thin Ti foil. Initial parameter scans showed that the optimum intensity is ~ 1015W/cm2 with a foil thickness of 2 μm for forward X-ray production. Bandwidth measurements of the source, using a HAPG crystal in the Von Hamos configuration, were found to be ΔE/E ~ 0.01. Giving the scattering angle of our experimental setup of 129 degrees and X-ray probing energy, the non-collective regime was accessed. The ZEBRA load was a 3 mm wide, 500 μm thick, and 10 mm long graphite foil, placed at one of the six current return posts. Estimates of the plasma temperature, density and ionization state were made by fitting the scattering spectra with dynamic structure factor calculations based on the random phase approximation for the treatment of charged particle coupling. The work was partially funded by the Department of Energy grant number DE-NA0001995.

  2. Effects of Laser Pulse Heating of Copper Photocathodes on High-brightness Electron Beam Production at Blowout Regime

    CERN Document Server

    Zheng, Lianmin; Tang, Chuanxiang; Gai, Wei

    2016-01-01

    Producing high-brightness and high-charge (>100 pC) electron bunches at blowout regime requires ultrashort laser pulse with high fluence. The effects of laser pulse heating of the copper photocathode are analyzed in this paper. The electron and lattice temperature is calculated using an improved two-temperature model, and an extended Dowell-Schmerge model is employed to calculate the thermal emittance and quantum efficiency. A time-dependent growth of the thermal emittance and the quantum efficiency is observed. For a fixed amount of charge, the projected thermal emittance increases with the decreasing laser radius, and this effect should be taken into account in the laser optimization at blowout regime. Moreover, laser damage threshold fluence is simulated, showing that the maximum local fluence should be less than 40 mJ/cm^2 to prevent damage to the cathode. The cryogenic effect on the laser pulse heating is studied, showing that the hazards caused by the laser pulse heating will be significantly mitigated ...

  3. 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.

  4. Hydrodynamics driven by ultrashort laser pulse: simulations and the optical pump—X-ray probe experiment

    Science.gov (United States)

    Inogamov, N. A.; Zhakhovsky, V. V.; Hasegawa, N.; Nishikino, M.; Yamagiwa, M.; Ishino, M.; Agranat, M. B.; Ashitkov, S. I.; Faenov, A. Ya.; Khokhlov, V. A.; Ilnitsky, D. K.; Petrov, Yu. V.; Migdal, K. P.; Pikuz, T. A.; Takayoshi, S.; Eyama, T.; Kakimoto, N.; Tomita, T.; Baba, M.; Minami, Y.; Suemoto, T.; Kawachi, T.

    2015-06-01

    Spatial structures of ablative mass flow produced by femtosecond laser pulses are studied. In experiments with a gold film, the Ti:sapp laser pulse having a focal size of 100 microns on a target was used, while a soft X-ray probe pulse was utilized for diagnostics. The experimental data are compared with simulated mass flows obtained by two-temperature hydrodynamics and molecular dynamics methods. Simulation shows evolution of a thin surface layer pressurized after electron-ion thermalization, which leads to melting, cavitation and formation of spallation liquid layer. The calculated asymptotic surface velocity of this layer as a function of fluence is in reasonably good agreement with experimental data.

  5. Testifying experiment of the multi-pulse phenomena of capillary discharge soft-X-ray laser

    Institute of Scientific and Technical Information of China (English)

    Bohan Luan; Yongpeng Zhao; Qi Wang; Yuanli Cheng; Yao Xie

    2008-01-01

    In a capillary discharge experiment for the neon-like argon lasing, we have proposed an experimental scheme to verify that the multi-spike of X-ray diode (XRD) signal is a multi-pulse laser or is a reflection of the laser pulse in the XRD.The ceramic capillary has an inner diameter of 3mm and a length of 200mm.At the gas pressure of 28Pa and discharge current of 27kA, stable lasing has been realized.The experimental results prove that the multi-spike of XRD signal is a reflection of the electromagnetic signal produced by the laser pulse in the XRD.The improved electrocircuit scheme of the XRD to minimize the reflection phenomena is also found.

  6. Femtosecond X-ray Pulses From a frequency chirped SASE FEL

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Z

    2003-01-14

    We discuss the temporal and spectral properties of self-amplified spontaneous emission (SASE) utilizing an energy-chirped electron beam. A short temporal pulse is generated by using a monochromator to select a narrow radiation bandwidth from the frequency chirped SASE. For the filtered radiation, the minimum pulse length is limited by the intrinsic SASE bandwidth, while the number of modes and the energy fluctuation can be controlled through the monochromator bandwidth. Two cases are considered: (1) placing the monochromator at the end of a single long undulator; (2) placing the monochromator after an initial undulator and amplifying the short-duration output in a second undulator. We analyze these cases and show that tens of femtosecond x-ray pulses may be generated for the linac coherent light source.

  7. Pulsed x-ray imaging of high-density objects using a ten picosecond high-intensity laser driver

    Science.gov (United States)

    Rusby, D. R.; Brenner, C. M.; Armstrong, C.; Wilson, L. A.; Clarke, R.; Alejo, A.; Ahmed, H.; Butler, N. M. H.; Haddock, D.; Higginson, A.; McClymont, A.; Mirfayzi, S. R.; Murphy, C.; Notley, M.; Oliver, P.; Allott, R.; Hernandez-Gomez, C.; Kar, S.; McKenna, P.; Neely, D.

    2016-10-01

    Point-like sources of X-rays that are pulsed (sub nanosecond), high energy (up to several MeV) and bright are very promising for industrial and security applications where imaging through large and dense objects is required. Highly penetrating X-rays can be produced by electrons that have been accelerated by a high intensity laser pulse incident onto a thin solid target. We have used a pulse length of 10ps to accelerate electrons to create a bright x-ray source. The bremsstrahlung temperature was measured for a laser intensity from 8.5-12×1018 W/cm2. These x-rays have sequentially been used to image high density materials using image plate and a pixelated scintillator system.

  8. Generation of Picosecond X-Ray Pulses in the ALS Using RF Orbit Deflection

    CERN Document Server

    Robin, David; Fischer, Peter; Heimann, Philip; Kim, Dong-Hyun; Kwiatkowski, Slawomir; Li, Derun; Sannibale, Fernando; Steier, Christoph; Wan, Weishi; Wittmer, Walter; Zholents, Alexander

    2005-01-01

    A scheme is studied for producing ps length pulses of x-ray radiation from the Advanced Light Source (ALS) using two RF deflecting cavities. The cavities create vertical displacements of electrons correlated with their longitudinal position in the bunch. The two cavities separated by 180 degrees of vertical phase advance. This allows the vertical kick from one cavity to be compensated by the vertical kick of the other. The location of the cavities corresponds to the end of one straight section and the beginning of the following straight section. Halfway between the cavities a bending magnet source is located. The radiation from the bend can be compressed to ~1 ps in duration.

  9. Interaction of femtosecond X-ray pulses with periodical multilayer structures

    Energy Technology Data Exchange (ETDEWEB)

    Ksenzov, Dmitry

    2010-07-01

    The VUV Free Electron Laser FLASH operates in soft X-ray range and produces high-intensive pulse trains with few tens femtoseconds duration. The transversely fully coherent beam will open new experiments in solid state physics which can not be studied with present radiation sources. The study of the time dependent response of the multilayer to the X-ray pulse can provide insights into the process of interaction of highly intense FEL radiation with matter. To test the influence of electron excitation on the optical properties of boron carbide, the refractive index of B{sub 4}C was measured near B K-edge by energy-resolved photon-in-photon-out method probing a Bragg reflection from periodical multilayers. The measured data clearly show that the variation of the fine structure of the Kabsorption edges due to the chemical nature of the absorber element. The knowledge obtained from experiments with continuous radiation was used to design the respective experiments with pulse from the FEL. In my thesis, it is proposed that the geometrical setup, where the incident pulse arrives from the FEL under the angle close to the 1st order ML Bragg peak, provides the most valuable information. Preliminary simulation considering form factors of neutral and ionized boron showed that due to ionization, pronounced changes in the reflectivity curve are expected. The proposed scheme can be the powerful tool to study the various processes within the electronic subsystem of the FEL pulse interaction with matter. This type of investigations gives a deep understanding of the nature of the electronic excitation and the recombination at the femtosecond scale. (orig.)

  10. Tailoring the amplification of attosecond pulse through detuned X-ray FEL undulator.

    Science.gov (United States)

    Kumar, Sandeep; Kang, Heung-Sik; Kim, Dong Eon

    2015-02-09

    We demonstrate that the amplification of attosecond pulse in X-ray free electron laser (FEL) undulator can be tailored. The characteristic of the amplification of an isolated attosecond pulse in the FEL undulator is investigated. An isolated 180 attoseconds full width half maximum (FWHM) pulse at 1.25 nm with a spectral bandwidth of 1% is injected into an undulator. The simulation results show that for a direct seeding of 3MW, the seed is amplified to the peak power of 106 GW (40 μJ, an output pulse-width of 383 attoseconds) in the presence of a detuning at FEL resonance condition in 100-m long undulator. We note that the introduction of detuning leads to the better performance compared to the case without detuning: shorter by 15.5% in a pulse-width and higher by 76.6% in an output power. Tapering yields a higher power (116% increases in the output power compared to the case without detuning) but a longer pulse (15.4% longer in the pulse-width). It was observed that ± Δλ(r)/8 (Δλ(r)/λ(r) ~1%) is the maximum degree of detuning, beyond which the amplification becomes poor: lower in the output power and longer in the pulse duration. The minimum power for a seed pulse needs to be higher than 1 MW for the successful amplification of an attosecond pulse at 1.25 nm. Also, the electron beam energy-spread must be less than 0.1% for a suitable propagation of attosecond pulse along the FEL undulator under this study.

  11. Generating femtosecond X-ray pulses using an emittance-spoiling foil in free-electron lasers

    Energy Technology Data Exchange (ETDEWEB)

    Ding, Y., E-mail: ding@slac.stanford.edu; Coffee, R.; Decker, F.-J.; Emma, P.; Field, C.; Huang, Z.; Krejcik, P.; Krzywinski, J.; Loos, H.; Lutman, A.; Marinelli, A.; Maxwell, T. J.; Turner, J. [SLAC National Accelerator Laboratory, Menlo Park, California 94025 (United States); Behrens, C. [Deutsches Elektronen-Synchrotron DESY, Notkestr. 85, 22607 Hamburg (Germany); Helml, W. [Technische Universität München, James-Franck-Straße 1, 85748 Garching (Germany)

    2015-11-09

    Generation of femtosecond to sub-femtosecond pulses is attracting much attention in X-ray free-electron laser user community. One method is to use a slotted, emittance-spoiling foil which was proposed before (P. Emma et al., Phys. Rev. Lett. 92, 074801 (2004)) and has been widely used at the Linac Coherent Light Source. Direct experimental characterization of the slotted-foil performance was previously unfeasible due to a lack of appropriate diagnostics. With a recently installed X-band radio-frequency transverse deflector, we are able to characterize the electron bunch spoiling effect and X-ray pulse when using the slotted foil. We show that few-femtosecond X-ray pulses are generated with flexible control of the single-pulse duration or double-pulse separation with comparison to the theoretical model.

  12. 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.

  13. Shaped-pulse optimization of coherent emission of high-harmonic soft X-rays

    Science.gov (United States)

    Bartels; Backus; Zeek; Misoguti; Vdovin; Christov; Murnane; Kapteyn

    2000-07-13

    When an intense laser pulse is focused into a gas, the light-atom interaction that occurs as atoms are ionized results in an extremely nonlinear optical process--the generation of high harmonics of the driving laser frequency. Harmonics that extend up to orders of about 300 have been reported, some corresponding to photon energies in excess of 500 eV. Because this technique is simple to implement and generates coherent, laser-like, soft X-ray beams, it is currently being developed for applications in science and technology; these include probing the dynamics in chemical and materials systems and imaging. Here we report that by carefully tailoring the shapes of intense light pulses, we can control the interaction of light with an atom during ionization, improving the efficiency of X-ray generation by an order of magnitude. We demonstrate that it is possible to tune the spectral characteristics of the emitted radiation, and to steer the interaction between different orders of nonlinear processes.

  14. NATO Advanced Study Institute on Chemical Crystallography with Pulsed Neutrons and Synchrotron X-Rays

    CERN Document Server

    Jeffrey, George

    1988-01-01

    X-ray and neutron crystallography have played an increasingly impor­ tant role in the chemical and biochemical sciences over the past fifty years. The principal obstacles in this methodology, the phase problem and com­ puting, have been overcome. The former by the methods developed in the 1960's and just recognised by the 1985 Chemistry Nobel Prize award to Karle and Hauptman, the latter by the dramatic advances that have taken place in computer technology in the past twenty years. Within the last decade, two new radiation sources have been added to the crystallographer's tools. One is synchrotron X-rays and the other is spallation neutrons. Both have much more powerful fluxes than the pre­ vious sources and they are pulsed rather than continuos. New techniques are necessary to fully exploit the intense continuos radiation spectrum and its pulsed property. Both radiations are only available from particular National Laboratories on a guest-user basis for scientists outside these Na­ tional Laboratories. Hi...

  15. Modulated method for efficient, narrow-bandwidth, laser Compton X-ray and gamma-ray sources

    Energy Technology Data Exchange (ETDEWEB)

    Barty, Christopher P. J.

    2017-07-11

    A method of x-ray and gamma-ray generation via laser Compton scattering uses the interaction of a specially-formatted, highly modulated, long duration, laser pulse with a high-frequency train of high-brightness electron bunches to both create narrow bandwidth x-ray and gamma-ray sources and significantly increase the laser to Compton photon conversion efficiency.

  16. Multiphoton Ionization as a clock to Reveal Molecular Dynamics with Intense Short X-ray Free Electron Laser Pulses

    CERN Document Server

    Fang, L; Murphy, B; Tarantelli, F; Kukk, E; Cryan, J P; Glownia, M; Bucksbaum, P H; Coffee, R N; Chen, M; Buth, C; Berrah, N

    2013-01-01

    We investigate molecular dynamics of multiple ionization in N2 through multiple core-level photoabsorption and subsequent Auger decay processes induced by intense, short X-ray free electron laser pulses. The timing dynamics of the photoabsorption and dissociation processes is mapped onto the kinetic energy of the fragments. Measurements of the latter allow us to map out the average internuclear separation for every molecular photoionization sequence step and obtain the average time interval between the photoabsorption events. Using multiphoton ionization as a tool of multiple-pulse pump-probe scheme, we demonstrate the modi?cation of the ionization dynamics as we vary the x-ray laser pulse duration.

  17. Generation of Short X-Ray Pulses Using Crab Cavities at the Advanced Photon Source

    CERN Document Server

    Harkay, Katherine C; Chae, Yong-Chul; Decker, Glenn; Dejus, Roger J; Emery, Louis; Guo, Weiming; Horan, Douglas; Kim, Kwang-Je; Kustom, Robert; Mills, Dennis M; Milton, Stephen; Pile, Geoffery; Sajaev, Vadim; Shastri, Sarvjit D; Waldschmidt, Geoff J; White, Marion; Yang Bing Xin; Zholents, Alexander

    2005-01-01

    There is growing interest within the user community to utilize the pulsed nature of synchrotron radiation from storage ring sources. Conventional third-generation light sources can provide pulses on the order of 100 ps but typically cannot provide pulses of about 1 ps that some users now require to advance their research programs. However, it was recently proposed by A. Zholents et al. to use rf orbit deflection to generate subpicosecond X-ray pulses.* In this scheme, two crab cavities are used to deliver a longitudinally dependent vertical kick to the beam, thus exciting longitudinally correlated vertical motion of the electrons. This makes it possible to spatially separate the radiation coming from different longitudinal parts of the beam. An optical slit can then be used to slice out a short part of the radiation pulse, or an asymetrically cut crystal can be used to compress the radiation in time. In this paper, we present a feasibility study of this method applied to the Advanced Photon Source. We find th...

  18. X-ray Spectra and Pulse Frequency Changes in SAX J2103.5+4545

    CERN Document Server

    Baykal, A; Swank, J H

    2002-01-01

    The November 1999 outburst of the transient pulsar SAX J2103.5+4545 was monitored with the large area detectors of the Rossi X-Ray Timing Explorer until the pulsar faded after a year. The 358 s pulsar was spun up for 150 days, at which point the flux dropped quickly by a factor of 7, the frequency saturated and, as the flux continued to decline, a weak spin-down began. The pulses remained strong during the decay and the spin-up/flux correlation can be fit to the Ghosh and Lamb derivations for the spin-up caused by accretion from a thin, pressure-dominated disk, for a distance 3.2 kpc and a surface magnetic field 1.2 10^{13} Gauss. During the bright spin-up part of the outburst, the flux was subject to strong orbital modulation, peaking 3 days after periastron of the eccentric 12.68 day orbit, while during the faint part, there was little orbital modulation. The X-ray spectra were typical of accreting pulsars, describable by a cut-off power-law, with an emission line near the 6.4 keV of K alpha fluorescence fr...

  19. Ultrafast emission from colloidal nanocrystals under pulsed X-ray excitation

    Science.gov (United States)

    Turtos, R. M.; Gundacker, S.; Polovitsyn, A.; Christodoulou, S.; Salomoni, M.; Auffray, E.; Moreels, I.; Lecoq, P.; Grim, J. Q.

    2016-10-01

    Fast timing has emerged as a critical requirement for radiation detection in medical and high energy physics, motivating the search for scintillator materials with high light yield and fast time response. However, light emission rates from conventional scintillation mechanisms fundamentally limit the achievable time resolution, which is presently at least one order of magnitude slower than required for next-generation detectors. One solution to this challenge is to generate an intense prompt signal in response to ionizing radiation. In this paper, we present colloidal semiconductor nanocrystals (NCs) as promising prompt photon sources. We investigate two classes of NCs: two-dimensional CdSe nanoplatelets (NPLs) and spherical CdSe/CdS core/giant shell quantum dots (GS QDs). We demonstrate that the emission rates of these NCs under pulsed X-ray excitation are much faster than traditional mechanisms in bulk scintillators, i.e. 5d-4f transitions. CdSe NPLs have a sub-100 ps effective decay time of 77 ps and CdSe/CdS GS QDs exhibit a sub-ns value of 849 ps. Further, the respective CdSe NPL and CdSe/CdS GS QD X-ray excited photoluminescence have the emission characteristics of excitons (X) and multiexcitons (MX), with the MXs providing additional prospects for fast timing with substantially shorter lifetimes.

  20. Molecular dynamics induced by short and intense x-ray pulses from the LCLS

    Science.gov (United States)

    Berrah, Nora

    2016-12-01

    The past six years have led to a wealth of experimental and theoretical data revealing the nature of the interaction between gas-phase molecules and short and intense x-ray pulses, from the Linac coherent light source free electron laser (FEL). We present here a few highlights that describe some of the first photoabsorption measurements of gas-phase molecules. In particular, we report on a three decades long prediction of single-site double core holes (ss-DCH) and two-site double core holes (ts-DCH) in diatomic and triatomic molecules. We also describe recent measurements that validate a simple theory regarding femtosecond intense x-ray induced fragmentation dynamics of C60 as well as photoabsorption measurements of encapsulated fullerenes, Ho3N@C80. The latter investigation opens the way for even more complex molecular studies with FELs. In all of the described highlights, working in close collaboration with theorists enabled the interpretation of, or predicted our measurements, and in some cases our experiments guided the modeling. We conclude this article by describing the potential of new instrumentation for chemical and biological sciences especially in light of new or improved FELs.

  1. Rapid excited state structural reorganization captured by pulsed x-rays.

    Energy Technology Data Exchange (ETDEWEB)

    Chen, L. X.; Jennings, G.; Liu, T.; Gosztola, D. J.; Hessler, J. P.; Scaltrito, D. V.; Meyer, G. J.; Johns Hopkins Univ.

    2002-09-11

    Visible light excitation of [CuI(dmp)2](BArF), where dmp is 2,9-dimethyl-1,10-phenanthroline and BArF is tetrakis(3,5-bis(trifluoromethylphenyl))borate, in toluene produces a photoluminescent, metal-to-ligand charge-transfer (MLCT) excited state with a lifetime of 98 {+-} 5 ns. Probing this state within 14 ns after photoexcitation with pulsed X-rays establishes that a CuII center, borne in a CuI geometry, binds an additional ligand to form a five-coordinate complex with increased bond lengths and a coordination geometry of distorted trigonal bipyramid. The average Cu-N bond length increases in the excited state by 0.07 Angstroms. The transiently formed five-coordinate MLCT state is photoluminescent under the condition studied, indicating that the absorptive and emissive states have distinct geometries. The data represent the first X-ray characterization of a molecular excited state in fluid solution on a nanosecond time scale.

  2. A fast pulse phase estimation method for X-ray pulsar signals based on epoch folding

    Institute of Scientific and Technical Information of China (English)

    Xue Mengfan; Li Xiaoping; Sun Haifeng; Fang Haiyan

    2016-01-01

    X-ray pulsar-based navigation (XPNAV) is an attractive method for autonomous deep-space navigation in the future. The pulse phase estimation is a key task in XPNAV and its accuracy directly determines the navigation accuracy. State-of-the-art pulse phase estimation techniques either suffer from poor estimation accuracy, or involve the maximization of generally non-convex object function, thus resulting in a large computational cost. In this paper, a fast pulse phase estimation method based on epoch folding is presented. The statistical properties of the observed profile obtained through epoch folding are developed. Based on this, we recognize the joint prob-ability distribution of the observed profile as the likelihood function and utilize a fast Fourier transform-based procedure to estimate the pulse phase. Computational complexity of the proposed estimator is analyzed as well. Experimental results show that the proposed estimator significantly outperforms the currently used cross-correlation (CC) and nonlinear least squares (NLS) estima-tors, while significantly reduces the computational complexity compared with NLS and maximum likelihood (ML) estimators.

  3. A fast pulse phase estimation method for X-ray pulsar signals based on epoch folding

    Directory of Open Access Journals (Sweden)

    Xue Mengfan

    2016-06-01

    Full Text Available X-ray pulsar-based navigation (XPNAV is an attractive method for autonomous deep-space navigation in the future. The pulse phase estimation is a key task in XPNAV and its accuracy directly determines the navigation accuracy. State-of-the-art pulse phase estimation techniques either suffer from poor estimation accuracy, or involve the maximization of generally non-convex object function, thus resulting in a large computational cost. In this paper, a fast pulse phase estimation method based on epoch folding is presented. The statistical properties of the observed profile obtained through epoch folding are developed. Based on this, we recognize the joint probability distribution of the observed profile as the likelihood function and utilize a fast Fourier transform-based procedure to estimate the pulse phase. Computational complexity of the proposed estimator is analyzed as well. Experimental results show that the proposed estimator significantly outperforms the currently used cross-correlation (CC and nonlinear least squares (NLS estimators, while significantly reduces the computational complexity compared with NLS and maximum likelihood (ML estimators.

  4. Constraints on photon pulse duration from longitudinal electron beam diagnostics at a soft x-ray free-electron laser

    Directory of Open Access Journals (Sweden)

    C. Behrens

    2012-03-01

    Full Text Available The successful operation of x-ray free-electron lasers (FELs, like the Linac Coherent Light Source or the Free-Electron Laser in Hamburg (FLASH, makes unprecedented research on matter at atomic length and ultrafast time scales possible. However, in order to take advantage of these unique light sources and to meet the strict requirements of many experiments in photon science, FEL photon pulse durations need to be known and tunable. This can be achieved by controlling the FEL driving electron beams, and high-resolution longitudinal electron beam diagnostics can be utilized to provide constraints on the expected FEL photon pulse durations. In this paper, we present comparative measurements of soft x-ray pulse durations and electron bunch lengths at FLASH. The soft x-ray pulse durations were measured by FEL radiation pulse energy statistics and compared to electron bunch lengths determined by frequency-domain spectroscopy of coherent transition radiation in the terahertz range and time-domain longitudinal phase space measurements. The experimental results, theoretical considerations, and simulations show that high-resolution longitudinal electron beam diagnostics provide reasonable constraints on the expected FEL photon pulse durations. In addition, we demonstrated the generation of soft x-ray pulses with durations below 50 fs (FWHM after the implementation of the new uniform electron bunch compression scheme used at FLASH.

  5. On the feasibility of nanocrystal imaging using intense and ultrashort 1.5 {\\AA} X-ray pulses

    CERN Document Server

    Caleman, C; Maia, F R N C; Ortiz, C; Parak, F G; Hajdu, J; van der Spoel, D; Chapman, H N; Timneanu, N

    2010-01-01

    Structural studies of biological macromolecules are severely limited by radiation damage. Traditional crystallography curbs the effects of damage by spreading damage over many copies of the molecule of interest. X-ray lasers, such as the recently built LINAC Coherent Light Source (LCLS), offer an additional opportunity for limiting damage by out-running damage processes with ultrashort and very intense X-ray pulses. Such pulses may allow the imaging of single molecules, clusters or nanoparticles, but coherent flash imaging will also open up new avenues for structural studies on nano- and micro-crystalline substances. This paper addresses the theoretical potentials and limitations of nanocrystallography with extremely intense coherent X-ray pulses. We use urea nanocrystals as a model for generic biological substances and simulate primary and secondary ionization dynamics in the crystalline sample. Our results establish conditions for ultrafast nanocrystallography diffraction experiments as a function of fluenc...

  6. Charge transfer in dissociating iodomethane and fluoromethane molecules ionized by intense femtosecond X-ray pulses

    Directory of Open Access Journals (Sweden)

    Rebecca Boll

    2016-07-01

    Full Text Available Ultrafast electron transfer in dissociating iodomethane and fluoromethane molecules was studied at the Linac Coherent Light Source free-electron laser using an ultraviolet-pump, X-ray-probe scheme. The results for both molecules are discussed with respect to the nature of their UV excitation and different chemical properties. Signatures of long-distance intramolecular charge transfer are observed for both species, and a quantitative analysis of its distance dependence in iodomethane is carried out for charge states up to I21+. The reconstructed critical distances for electron transfer are in good agreement with a classical over-the-barrier model and with an earlier experiment employing a near-infrared pump pulse.

  7. Electronic excitation by short x-ray pulses: from quantum beats to wave packet revivals

    Science.gov (United States)

    Rivière, P.; Iqbal, S.; Rost, J. M.

    2014-06-01

    We propose a simple way to determine the periodicities of wave packets (WPs) in quantum systems directly from the energy differences of the states involved. The resulting classical periods and revival times are more accurate than those obtained with the traditional expansion of the energies about the central quantum number \\overline{n}, especially when \\overline{n} is low. The latter type of WP motion occurs upon excitation of highly charged ions with short XUV or x-ray pulses. Moreover, we formulate the WP dynamics in such a form that it directly reveals the origin of phase shifts in the maxima of the autocorrelation function, a phenomenon most prominent in the low \\overline{n} WP dynamics.

  8. Recombination-Enhanced Surface Expansion of Clusters in Intense Soft X-Ray Laser Pulses

    Science.gov (United States)

    Rupp, Daniela; Flückiger, Leonie; Adolph, Marcus; Gorkhover, Tais; Krikunova, Maria; Müller, Jan Philippe; Müller, Maria; Oelze, Tim; Ovcharenko, Yevheniy; Röben, Benjamin; Sauppe, Mario; Schorb, Sebastian; Wolter, David; Mitzner, Rolf; Wöstmann, Michael; Roling, Sebastian; Harmand, Marion; Treusch, Rolf; Arbeiter, Mathias; Fennel, Thomas; Bostedt, Christoph; Möller, Thomas

    2016-10-01

    We studied the nanoplasma formation and explosion dynamics of single large xenon clusters in ultrashort, intense x-ray free-electron laser pulses via ion spectroscopy. The simultaneous measurement of single-shot diffraction images enabled a single-cluster analysis that is free from any averaging over the cluster size and laser intensity distributions. The measured charge state-resolved ion energy spectra show narrow distributions with peak positions that scale linearly with final ion charge state. These two distinct signatures are attributed to highly efficient recombination that eventually leads to the dominant formation of neutral atoms in the cluster. The measured mean ion energies exceed the value expected without recombination by more than an order of magnitude, indicating that the energy release resulting from electron-ion recombination constitutes a previously unnoticed nanoplasma heating process. This conclusion is supported by results from semiclassical molecular dynamics simulations.

  9. Status of the Short-Pulse X-ray Project at the Advanced Photon Source

    Energy Technology Data Exchange (ETDEWEB)

    Nassiri, A; Berenc, T G; Borland, M; Brajuskovic, B; Bromberek, D J; Carwardine, J; Decker, G; Emery, L; Fuerst, J D; Grelick, A E; Horan, D; Kaluzny, J; Lenkszus, F; Lill, R M; Liu, J; Ma, H; Sajaev, V; Smith, T L; Stillwell, B K; Waldschmidt, G J; Wu, G; Yang, B X; Yang, Y; Zholents, A; Byrd, J M; Doolittle, L R; Huang, G; Cheng, G; Ciovati, G; Dhakal, P; Eremeev, G V; Feingold, J J; Geng, R L; Henry, J; Kneisel, P; Macha, K; Mammosser, J D; Matalevich, J; Palczewski, A D; Rimmer, R A; Wang, H; Wilson, K M; Wiseman, M; Li, Z

    2012-07-01

    The Advanced Photon Source Upgrade (APS-U) Project at Argonne will include generation of short-pulse x-rays based on Zholents deflecting cavity scheme. We have chosen superconducting (SC) cavities in order to have a continuous train of crabbed bunches and flexibility of operating modes. In collaboration with Jefferson Laboratory, we are prototyping and testing a number of single-cell deflecting cavities and associated auxiliary systems with promising initial results. In collaboration with Lawrence Berkeley National Laboratory, we are working to develop state-of-the-art timing, synchronization, and differential rf phase stability systems that are required for SPX. Collaboration with Advanced Computations Department at Stanford Linear Accelerator Center is looking into simulations of complex, multi-cavity geometries with lower- and higher-order modes waveguide dampers using ACE3P. This contribution provides the current R&D status of the SPX project.

  10. Highly enhanced hard x-ray emission from oriented metal nanorod arrays excited by intense femtosecond laser pulses

    Science.gov (United States)

    Mondal, Sudipta; Chakraborty, Indrani; Ahmad, Saima; Carvalho, Daniel; Singh, Prashant; Lad, Amit D.; Narayanan, V.; Ayyub, Pushan; Kumar, G. Ravindra; Zheng, J.; Sheng, Z. M.

    2011-01-01

    We report a 43-fold enhancement in the hard x-ray emission (in the 150-300 keV range) from copper nanorod arrays (compared to a polished Cu surface) when excited by 30-fs, 800-nm laser pulses with an intensity of 1016 W/cm2. The temperature of the hot electrons that emit the x rays is 11 times higher. Significantly, the x-ray yield enhancement is found to depend on both the aspect ratio as well as the cluster size of the nanorods. We show that the higher yield arises from enhanced laser absorption owing to the extremely high local electric fields around the nanorod tips. Particle-in-cell plasma simulations reproduce these observations and provide pointers to further optimization of the x-ray emission.

  11. Pulsed X-ray radiography of a gas jet target for laser-matter interaction experiments with the use of a CCD detector

    Energy Technology Data Exchange (ETDEWEB)

    Rakowski, R. [Institute of Optoelectronics, Military University of Technology, 2 Kaliskiego Street, 00-908 Warsaw (Poland); Bartnik, A. [Institute of Optoelectronics, Military University of Technology, 2 Kaliskiego Street, 00-908 Warsaw (Poland); Fiedorowicz, H. [Institute of Optoelectronics, Military University of Technology, 2 Kaliskiego Street, 00-908 Warsaw (Poland)]. E-mail: hfiedorowicz@wat.edu.pl; Jarocki, R. [Institute of Optoelectronics, Military University of Technology, 2 Kaliskiego Street, 00-908 Warsaw (Poland); Kostecki, J. [Institute of Optoelectronics, Military University of Technology, 2 Kaliskiego Street, 00-908 Warsaw (Poland); MikoIajczyk, J. [Institute of Optoelectronics, Military University of Technology, 2 Kaliskiego Street, 00-908 Warsaw (Poland); Szczurek, A. [Institute of Optoelectronics, Military University of Technology, 2 Kaliskiego Street, 00-908 Warsaw (Poland); Szczurek, M. [Institute of Optoelectronics, Military University of Technology, 2 Kaliskiego Street, 00-908 Warsaw (Poland); Foeldes, I.B. [KFKI-Research Institute for Particle and Nuclear Physics, Association EURATOM, P.O. Box 49, H-1525 Budapest (Hungary); Toth, Zs. [Department of Optics and Quantum Electronics, University of Szeged, H-6701 Szeged, Pf.: 406 (Hungary)

    2005-10-01

    Characterization of gas jet targets has been carried out using pulsed X-ray radiography. A laser-plasma X-ray source was applied for backlighting of the targets to obtain X-ray shadowgraphs registered with a CCD detector. From the shadowgraphs, characteristics of the targets were determined.

  12. Characterization of a medical X-ray machine for testing the response of electronic dosimeters in pulsed radiation fields

    Science.gov (United States)

    Guimarães, Margarete C.; Da Silva, Teógenes A.

    2014-11-01

    Electronic personal dosimeters (EPD) based on solid state detectors have been used for personnel monitoring for radiation protection purpose; their use has been extended to practices with pulsed radiation beams although their performance is not well known. Deficiencies in the EPD response in pulsed radiation fields have been reported; they were not detected before since type tests and calibrations of EPDs were established in terms of continuous X and gamma reference radiations. An ISO working group was formed to elaborate a standard for test conditions and performance requirements of EPDs in pulsed beams; the PTB/Germany implemented a special X-ray facility for generating the reference pulsed radiation beams. In this work, an 800 Plus VMI medical X-ray machine of the Dosimeter Calibration Laboratory of CDTN/CNEN was characterized to verify its feasibility to perform EPD tests. Characterization of the x-ray beam was done in terms of practical peak voltage, half-value layer, mean energy and air kerma rate. Reference dosimeters used for air kerma measurements were verified as far their metrological coherence and a procedure for testing EDPs was established. Electronic personal dosimeters (EPD) have been used for personnel monitoring. EPD use has been extended to pulsed radiation beams. Deficiencies in the EPD response in pulsed beams have been reported. The feasibility of using a medical X-ray machine to perform EPD tests was studied. Reference dosimeters were verified and EPD testing procedure was established.

  13. Performance assessment of different pulse reconstruction algorithms for the ATHENA X-ray Integral Field Unit

    Science.gov (United States)

    Peille, Philippe; Ceballos, Maria Teresa; Cobo, Beatriz; Wilms, Joern; Bandler, Simon; Smith, Stephen J.; Dauser, Thomas; Brand, Thorsten; den Hartog, Roland; de Plaa, Jelle; Barret, Didier; den Herder, Jan-Willem; Piro, Luigi; Barcons, Xavier; Pointecouteau, Etienne

    2016-07-01

    The X-ray Integral Field Unit (X-IFU) microcalorimeter, on-board Athena, with its focal plane comprising 3840 Transition Edge Sensors (TESs) operating at 90 mK, will provide unprecedented spectral-imaging capability in the 0.2-12 keV energy range. It will rely on the on-board digital processing of current pulses induced by the heat deposited in the TES absorber, as to recover the energy of each individual events. Assessing the capabilities of the pulse reconstruction is required to understand the overall scientific performance of the X-IFU, notably in terms of energy resolution degradation with both increasing energies and count rates. Using synthetic data streams generated by the X-IFU End-to-End simulator, we present here a comprehensive benchmark of various pulse reconstruction techniques, ranging from standard optimal filtering to more advanced algorithms based on noise covariance matrices. Beside deriving the spectral resolution achieved by the different algorithms, a first assessment of the computing power and ground calibration needs is presented. Overall, all methods show similar performances, with the reconstruction based on noise covariance matrices showing the best improvement with respect to the standard optimal filtering technique. Due to prohibitive calibration needs, this method might however not be applicable to the X-IFU and the best compromise currently appears to be the so-called resistance space analysis which also features very promising high count rate capabilities.

  14. 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.

  15. Generation of bright attosecond x-ray pulse trains via Thomson scattering from laser-plasma accelerators.

    Science.gov (United States)

    Luo, W; Yu, T P; Chen, M; Song, Y M; Zhu, Z C; Ma, Y Y; Zhuo, H B

    2014-12-29

    Generation of attosecond x-ray pulse attracts more and more attention within the advanced light source user community due to its potentially wide applications. Here we propose an all-optical scheme to generate bright, attosecond hard x-ray pulse trains by Thomson backscattering of similarly structured electron beams produced in a vacuum channel by a tightly focused laser pulse. Design parameters for a proof-of-concept experiment are presented and demonstrated by using a particle-in-cell code and a four-dimensional laser-Compton scattering simulation code to model both the laser-based electron acceleration and Thomson scattering processes. Trains of 200 attosecond duration hard x-ray pulses holding stable longitudinal spacing with photon energies approaching 50 keV and maximum achievable peak brightness up to 1020 photons/s/mm2/mrad2/0.1%BW for each micro-bunch are observed. The suggested physical scheme for attosecond x-ray pulse trains generation may directly access the fastest time scales relevant to electron dynamics in atoms, molecules and materials.

  16. X-Ray and Extreme Ultraviolet Emission from Small-Sized Kr Clusters Irradiated by 150-fs Laser Pulses

    Institute of Scientific and Technical Information of China (English)

    王骐; 程元丽; 赵永蓬; 夏元钦; 陈建新; 肖亦凡

    2003-01-01

    x-ray and extreme ultraviolet (EUV) emission from Kr clusters irradiated by 150-fs laser pulses at the peak laser intensity of 5×1015W/cm2 was experimentally investigated. Strong transitions (10nm-13nm) from Kr X and Kr 1X were observed and some spectral lines from Kr ⅩⅢ and Kr ⅩⅣ, which have been predicted to be not produced by optical-field-ionization at the laser intensity used, also appeared. The laser energy absorption and the intensity of x-ray emission started to grow remarkably above the backing pressure of 0.5 MPa and to decrease at the backing pressure of 3 MPa. It is suggested that an optimum backing pressure may exist for Kr clusters heated by 150 fs laser pulses at a certain laser intensity to produce x-ray emission.

  17. Enhanced X-ray emission from laser-produced gold plasma by double pulses irradiation of nano-porous targets

    Science.gov (United States)

    Fazeli, R.

    2017-02-01

    Enhancement of the soft X-ray emission including free-free, free-bound and bound-bound emissions from Au nano-porous targets irradiated by single and double laser pulses is studied through numerical simulations. Laser pulses of duration 2 ns are used in calculations considering different prepulse intensities and a fixed intensity of 1013 Wcm-2 for the main pulse. The effects of prepulse intensity and time separation between laser pulses are studied for targets of different porosities. Results show that the X-ray yield can be enhanced significantly by a nano-porous target having optimum initial density. Such enhancement can be more improved when double laser pulses with appropriate delay time and intensities irradiate nano-porous targets. It is shown that the enhancement will be reduced when the prepulse intensity is greater than a specific value.

  18. Soft-x-ray imaging from an ultrashort-pulse laser-produced plasma using a multilayer coated optic

    Science.gov (United States)

    Norby, J. R.; van Woerkom, L. D.

    1996-02-01

    Measurements are presented of soft-x-ray images from a plasma produced by a high-intensity ultrashort-pulse laser. For the intensity range of 1015-1016 W / cm2 the soft-x-ray source appears to follow the spatial profile of the driving laser. A curved multilayer coated optic is used to collect 13.5-nm light and form a magnified image of the plasma. Knife-edge scans have been performed in the image plane and show a geometrically limited spot size of 280 mu m.

  19. Quantum interference in laser-assisted photo-ionization excited by a femtosecond x-ray pulse

    Institute of Scientific and Technical Information of China (English)

    Ge Yu-Cheng

    2008-01-01

    The photoelectron energy spectra (PESs) excited by monochromatic femtosecond x-ray pulses in the presence of a femtosecond laser are investigated. APES is composed of a set of separate peaks, showing interesting comb-like structures. These structures result from the quantum interferences between photoelectron wave packets generated at different times. The width and the localization of each peak as well as the number of peaks are determined by all the laser and x-ray parameters. Most of peak heights of the PES are higher than the classical predictions.

  20. Effect of Ultrashort Pulsed Laser and X-Ray Irradiation on Au~+ -Doped Glass

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Au nanoparticles were precipitated inside Au+-doped glass samples after irradiation by femtosecond laser or x-ray. Femtosecond laser and X-ray irradiation result in decreasing of anneal temperature and critical size for the precipitation of Au nanoparticles.

  1. Effect of Ultrashort Pulsed Laser and X-Ray Irradiation on Au+ -Doped Glass

    Institute of Scientific and Technical Information of China (English)

    Huidan Zeng; Jianrong Qiu; Xiongwei Jiang; Congshan Zhu; Fuxi Gan

    2003-01-01

    Au nanoparticles were precipitated inside Au+-doped glass samples after irradiation by femtosecond laser or x-ray. Femtosecond laser and X-ray irradiation result in decreasing of anneal temperature and critical size for the precipitation of Au nanoparticles.

  2. Generation of attosecond x-ray pulses with a multi-cycle two-color ESASE scheme

    Energy Technology Data Exchange (ETDEWEB)

    Ding, Y.; Huang, Z.; Ratner, D.; Bucksbaum, P.; /SLAC; Merdji, H.; /Saclay /SLAC

    2009-03-04

    Generation of attosecond x-ray pulses is attracting much attention within the x-ray free-electron laser (FEL) user community. Several schemes using extremely short laser pulses to manipulate the electron bunches have been proposed. In this paper, we extend the attosecond two-color ESASE scheme proposed by Zholents et al. to the long optical cycle regime using a second detuned laser and a tapered undulator. Both lasers can be about ten-optical-cycles long, with the second laser frequency detuned from the first to optimize the contrast between the central and side current spikes. A tapered undulator mitigates the degradation effect of the longitudinal space charge (LSC) force in the undulator and suppresses the FEL gain of all side current peaks. Simulations using the LCLS parameters show a single attosecond x-ray spike of {approx} 110 attoseconds can be produced. The second laser can also be detuned to coherently control the number of the side x-ray spikes and the length of the radiation pulse.

  3. Optimization of Drive Pulse Configuration for a High-Gain Transient X-Ray Laser at 19.6 nm

    Institute of Scientific and Technical Information of China (English)

    LU Xin; LI Ying-Jun; ZHANG Jie

    2001-01-01

    An Ne-like transient collisional excitation x-ray laser at 19.6nm (J = 0 → 1, 3p - 3s) was investigated numerically using a sophisticated hydrodynamic code for a l00μm thick Ge planar target irradiated by a nanosecond pre pulse followed by a picosecond main optical laser pulse. The simulations indicate that for a given peak intensity, the main pulse has an optimal duration to generate the maximum effective gain. An effective gain as high as 200 cma-1 was obtained for the optimized drive pulse configuration.

  4. Ultrafast emission from colloidal nanocrystals under pulsed X-ray excitation

    CERN Document Server

    Turtos, R.M.; Polovitsyn, A.; Christodoulou, S.; Salomoni, M.; Auffray, E.; Moreels, I.; Lecoq, P.; Grim, J.Q.

    2016-01-01

    Fast timing has emerged as a critical requirement for radiation detection in medical and high energy physics, motivating the search for scintillator materials with high light yield and fast time response. However, light emission rates from conventional scintillation mechanisms fundamentally limit the achievable time resolution, which is presently at least one order of magnitude slower than required for next-generation detectors. One solution to this challenge is to generate an intense prompt signal in response to ionizing radiation. In this paper, we present colloidal semiconductor nanocrystals (NCs) as promising prompt photon sources. We investigate two classes of NCs: two-dimensional CdSe nanoplatelets (NPLs) and spherical CdSe/CdS core/giant shell quantum dots (GS QDs). We demonstrate that the emission rates of these NCs under pulsed X-ray excitation are much faster than traditional mechanisms in bulk scintillators, i.e. 5d-4f transitions. CdSe NPLs have a sub-100 ps effective decay time of 77 ps and CdSe/...

  5. Transient X-ray pulsar V0332+53: pulse phase-resolved spectroscopy and the reflection model

    CERN Document Server

    Lutovinov, A A; Suleimanov, V F; Mushtukov, A A; Doroshenko, V; Nagirner, D I; Poutanen, J

    2015-01-01

    We present the results of the pulse phase- and luminosity-resolved spectroscopy of the transient X-ray pulsar V0332+53, performed for the first time in a wide luminosity range (1-40)x10^{37} erg/s during a giant outburst observed by the RXTE observatory in Dec 2004 - Feb 2005. We characterize the spectra quantitatively and built the detailed "three-dimensional" picture of spectral variations with pulse phase and throughout the outburst. We show that all spectral parameters are strongly variable with the pulse phase, and the pattern of this variability significantly changes with luminosity directly reflecting the associated changes in the structure of emission regions and their beam patterns. Obtained results are qualitatively discussed in terms of the recently developed reflection model for the formation of cyclotron lines in the spectra of X-ray pulsars.

  6. Unusual Pulsed X-Ray Emission from the Young, High Magnetic Field Pulsar PSR J1119--6127

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, M E; Kaspi, V M; Camilo, F; Gaensler, B M; Pivovaroff, M J

    2005-08-05

    We present XMM-Newton observations of the radio pulsar PSR J1119-6127, which has an inferred age of 1,700 yr and surface dipole magnetic field strength of 4.1 x 10{sup 13} G. We report the first detection of pulsed X-ray emission from PSR J1119-6127. In the 0.5-2.0 keV range, the pulse profile shows a narrow peak with a very high pulsed fraction of (74 {+-} 14)%. In the 2.0-10.0 keV range, the upper limit for the pulsed fraction is 28% (99% confidence). The pulsed emission is well described by a thermal blackbody model with a temperature of T{infinity} = 2.4{sub -0.2}{sup +0.3} x 10{sup 6} K and emitting radius of 3.4{sub -0.3}{sup +1.8} km (at a distance of 8.4 kpc). Atmospheric models result in problematic estimates for the distance/emitting area. PSR J1119-6127 is now the radio pulsar with smallest characteristic age from which thermal X-ray emission has been detected. The combined temporal and spectral characteristics of this emission are unlike those of other radio pulsars detected at X-ray energies and challenge current models of thermal emission from neutron stars.

  7. Sub-nanosecond time-resolved ambient-pressure X-ray photoelectron spectroscopy setup for pulsed and constant wave X-ray light sources.

    Science.gov (United States)

    Shavorskiy, Andrey; Neppl, Stefan; Slaughter, Daniel S; Cryan, James P; Siefermann, Katrin R; Weise, Fabian; Lin, Ming-Fu; Bacellar, Camila; Ziemkiewicz, Michael P; Zegkinoglou, Ioannis; Fraund, Matthew W; Khurmi, Champak; Hertlein, Marcus P; Wright, Travis W; Huse, Nils; Schoenlein, Robert W; Tyliszczak, Tolek; Coslovich, Giacomo; Robinson, Joseph; Kaindl, Robert A; Rude, Bruce S; Ölsner, Andreas; Mähl, Sven; Bluhm, Hendrik; Gessner, Oliver

    2014-09-01

    An apparatus for sub-nanosecond time-resolved ambient-pressure X-ray photoelectron spectroscopy studies with pulsed and constant wave X-ray light sources is presented. A differentially pumped hemispherical electron analyzer is equipped with a delay-line detector that simultaneously records the position and arrival time of every single electron at the exit aperture of the hemisphere with ~0.1 mm spatial resolution and ~150 ps temporal accuracy. The kinetic energies of the photoelectrons are encoded in the hit positions along the dispersive axis of the two-dimensional detector. Pump-probe time-delays are provided by the electron arrival times relative to the pump pulse timing. An average time-resolution of (780 ± 20) ps (FWHM) is demonstrated for a hemisphere pass energy E(p) = 150 eV and an electron kinetic energy range KE = 503-508 eV. The time-resolution of the setup is limited by the electron time-of-flight (TOF) spread related to the electron trajectory distribution within the analyzer hemisphere and within the electrostatic lens system that images the interaction volume onto the hemisphere entrance slit. The TOF spread for electrons with KE = 430 eV varies between ~9 ns at a pass energy of 50 eV and ~1 ns at pass energies between 200 eV and 400 eV. The correlation between the retarding ratio and the TOF spread is evaluated by means of both analytical descriptions of the electron trajectories within the analyzer hemisphere and computer simulations of the entire trajectories including the electrostatic lens system. In agreement with previous studies, we find that the by far dominant contribution to the TOF spread is acquired within the hemisphere. However, both experiment and computer simulations show that the lens system indirectly affects the time resolution of the setup to a significant extent by inducing a strong dependence of the angular spread of electron trajectories entering the hemisphere on the retarding ratio. The scaling of the angular spread with

  8. A simulation study of Tsinghua Thomson scattering X-ray source

    Institute of Scientific and Technical Information of China (English)

    TANG Chuan-Xiang; LI Ren-Kai; HUANG Wen-Hui; CHEN Huai-Bi; DU Ying-Chao; DU Qiang; DU Tai-Bin; HE Xiao-Zhong; HUA Jian-Fei; LIN Yu-Zhen; QIAN Hou-Jun; SHI Jia-Ru; XIANG Dao; YAN Li-Xin; Yu Pei-Cheng

    2009-01-01

    Thomson scattering X-ray sources are compact and afrordable facifities that produce short duration,high brightness X-ray pulses enabling new experimental capacities in ultra-fast science studies,and also medical and industrial applications.Such a facility has been built at the Accelerator Laboratory of Tsinghua University,and upgrade is in progress.In this paper,we present a proposed layout of the upgrade with design parameters by simulation,aiming at high X-ray pulses flux and brightness,and also enabling advanced dynamics studies and applications of the electron beam.Design and construction status of main subsystems are also presented.

  9. LIGHT SOURCE: A simulation study of Tsinghua Thomson scattering X-ray source

    Science.gov (United States)

    Tang, Chuan-Xiang; Li, Ren-Kai; Huang, Wen-Hui; Chen, Huai-Bi; Du, Ying-Chao; Du, Qiang; Du, Tai-Bin; He, Xiao-Zhong; Hua, Jian-Fei; Lin, Yu-Zhen; Qian, Hou-Jun; Shi, Jia-Ru; Xiang, Dao; Yan, Li-Xin; Yu, Pei-Cheng

    2009-06-01

    Thomson scattering X-ray sources are compact and affordable facilities that produce short duration, high brightness X-ray pulses enabling new experimental capacities in ultra-fast science studies, and also medical and industrial applications. Such a facility has been built at the Accelerator Laboratory of Tsinghua University, and upgrade is in progress. In this paper, we present a proposed layout of the upgrade with design parameters by simulation, aiming at high X-ray pulses flux and brightness, and also enabling advanced dynamics studies and applications of the electron beam. Design and construction status of main subsystems are also presented.

  10. Pulse-by-pulse multi-beam-line operation for x-ray free-electron lasers

    Directory of Open Access Journals (Sweden)

    Toru Hara

    2016-02-01

    Full Text Available The parallel operation of plural undulator beam lines is an important means of improving the efficiency and usability of x-ray free-electron laser facilities. After the installation of a second undulator beam line (BL2 at SPring-8 Angstrom compact free-electron laser (SACLA, pulse-by-pulse switching between two beam lines was tested using kicker and dc twin-septum magnets. To maintain a compact size, all undulator beam lines at SACLA are designed to be placed within the same undulator hall located downstream of the accelerator. In order to ensure broad tunability of the laser wavelength, the electron bunches are accelerated to different beam energies optimized for the wavelengths of each beam line. In the demonstration, the 30 Hz electron beam was alternately deflected to two beam lines and simultaneous lasing was achieved with 15 Hz at each beam line. Since the electron beam was deflected twice by 3° in a dogleg to BL2, the coherent synchrotron radiation (CSR effects became non-negligible. Currently in a wavelength range of 4–10 keV, a laser pulse energy of 100–150  μJ can be obtained with a reduced peak current of around 1 kA by alleviating the CSR effects. This paper reports the results and operational issues related to the multi-beam-line operation of SACLA.

  11. Ultrafast Dynamics of a Nucleobase Analogue Illuminated by a Short Intense X-ray Free Electron Laser Pulse

    Science.gov (United States)

    Nagaya, K.; Motomura, K.; Kukk, E.; Fukuzawa, H.; Wada, S.; Tachibana, T.; Ito, Y.; Mondal, S.; Sakai, T.; Matsunami, K.; Koga, R.; Ohmura, S.; Takahashi, Y.; Kanno, M.; Rudenko, A.; Nicolas, C.; Liu, X.-J.; Zhang, Y.; Chen, J.; Anand, M.; Jiang, Y. H.; Kim, D.-E.; Tono, K.; Yabashi, M.; Kono, H.; Miron, C.; Yao, M.; Ueda, K.

    2016-04-01

    Understanding x-ray radiation damage is a crucial issue for both medical applications of x rays and x-ray free-electron-laser (XFEL) science aimed at molecular imaging. Decrypting the charge and fragmentation dynamics of nucleobases, the smallest units of a macro-biomolecule, contributes to a bottom-up understanding of the damage via cascades of phenomena following x-ray exposure. We investigate experimentally and by numerical simulations the ultrafast radiation damage induced on a nucleobase analogue (5-iodouracil) by an ultrashort (10 fs) high-intensity radiation pulse generated by XFEL at SPring-8 Angstrom Compact free electron Laser (SACLA). The present study elucidates a plausible underlying radiosensitizing mechanism of 5-iodouracil. This mechanism is independent of the exact composition of 5-iodouracil and thus relevant to other such radiosensitizers. Furthermore, we found that despite a rapid increase of the net molecular charge in the presence of iodine, and of the ultrafast release of hydrogen, the other atoms are almost frozen within the 10-fs duration of the exposure. This validates single-shot molecular imaging as a consistent approach, provided the radiation pulse used is brief enough.

  12. ULTRA-BRIGHT X-RAY GENERATION USING INVERSE COMPTON SCATTERING OF PICOSECOND CO(2) LASER PLUSES.

    Energy Technology Data Exchange (ETDEWEB)

    TSUNEMI,A.; ENDO,A.; POGORELSKY,I.; BEN-ZVI,I.; KUSCHE,K.; SKARITKA,J.; YAKIMENKO,V.; HIROSE,T.; URAKAWA,J.; OMORI,T.; WASHIO,M.; LIU,Y.; HE,P.; CLINE,D.

    1999-03-01

    Laser-Compton scattering with picosecond CO{sub 2} laser pulses is proposed for generation of high-brightness x-rays. The interaction chamber has been developed and the experiment is scheduled for the generation of the x-rays of 4.7 keV, 10{sup 7} photons in 10-ps pulse width using 50-MeV, 0.5-nC relativistic electron bunches and 6 GW CO{sub 2} laser.

  13. The 5 Hour Pulse Period and Broadband Spectrum of the Symbiotic X-Ray Binary 3A 1954+319

    Science.gov (United States)

    Marcu, Diana M.; Fuerst, Felix; Pottschmidt, Katja; Grinberg, Victoria; Miller, Sebstian; Wilms, Joern; Postnov, Konstantin A.; Corbet, Robin H. D.; Markwardt, Craig B.; Cadolle Bel, Marion

    2011-01-01

    We present an analysis of the highly variable accreting X-ray pulsar 3A 1954+319 using 2005-2009 monitoring data obtained with INTEGRAL and Swift. This considerably extends the pulse period history and covers flaring episodes in 2005 and 2008. In 2006 the source was identified as one of only a few known symbiotic X-ray binaries, Le" systems composed of a neutron star accreting from the inhomogeneous medium around an M-giant star. The extremely long pulse period of approximately 5.3 h is directly visible in the 2008 INTEGRAL-ISGRI outburst light curve. The pulse profile is double peaked and not significantly energy dependent. During the outburst a strong spin-up of -1.8 x 10(exp -4) h h(exp -1) occurred. Between 2005 and 2008 a long term spin-down trend of 2.1 x 10(exp -5) h h(exp -1) was observed for the first time for this source. The 3-80 keV pulse peak spectrum of 3A 1954+319 during the 2008 flare could be well described by a thermal Comptonization model. We interpret the results within the framework of a recently developed quasi-spherical accretion model for symbiotic X-ray binaries.

  14. Long-Term Time Variability in the X-Ray Pulse Shape of the Crab Nebula Pulsar

    Science.gov (United States)

    Fazio, Giovanni G.

    2000-01-01

    This is the final performance report for our grant 'Long-Term Time Variability in the X-Ray Pulse Shape of the Crab Nebula Pulsar.' In the first year of this grant, we received the 50,000-second ROSAT (German acronym for X-ray satellite) High Resolution Images (HRI) observation of the Crab Nebula pulsar. We used the data to create a 65-ms-resolution pulse profile and compared it to a similar pulse profile obtained in 1991. No statistically significant differences were found. These results were presented at the January 1998 meeting of the American Astronomical Society. Since then, we have performed more sensitive analyses to search for potential changes in the pulse profile shape between the two data sets. Again, no significant variability was found. In order to augment this long (six-year) baseline data set, we have analyzed archival observations of the Crab Nebula pulsar with the Rossi X-Ray Timing Explorer (RXTE). While these observations have shorter time baselines than the ROSAT data set, their higher signal-to-noise offers similar sensitivity to long-term variability. Again, no significant variations have been found, confirming our ROSAT results. This work was done in collaboration with Prof. Stephen Eikenberry, Cornell University. These analyses will be included in Cornell University graduate student Dae-Sik Moon's doctoral thesis.

  15. Discovery of Pulsed X-ray Emission from the SMC Transient RX J0117.6-7330

    CERN Document Server

    Macomb, D J; Harmon, B A; Lamb, R C; Prince, T A

    1999-01-01

    We report on the detection of pulsed, broad-band, X-ray emission from the transient source RX J0117.6-7330. The pulse period of 22 seconds is detected by the ROSAT/PSPC instrument in a 1992 Sep 30 - Oct 2 observation and by the CGRO/BATSE instrument during the same epoch. Hard X-ray pulsations are detectable by BATSE for approximately 100 days surrounding the ROSAT observation (1992 Aug 28 - Dec 8). The total directly measured X-ray luminosity during the ROSAT observation is 1.0E38 (d/60 kpc)^2 ergs s-1. The pulse frequency increases rapidly during the outburst, with a peak spin-up rate of 1.2E-10 Hz s-1 and a total frequency change 1.8%. The pulsed percentage is 11.3% from 0.1-2.5 keV, increasing to at least 78% in the 20-70 keV band. These results establish RX J0117.6-7330 as a transient Be binary system.

  16. Characterization of electrons and x-rays produced using chirped laser pulses in a laser wakefield accelerator

    Science.gov (United States)

    Zhao, T. Z.; Behm, K.; He, Z.-H.; Maksimchuk, A.; Nees, J. A.; Yanovsky, V.; Thomas, A. G. R.; Krushelnick, K.

    2016-11-01

    The electron injection process into a plasma-based laser wakefield accelerator can be influenced by modifying the parameters of the driver pulse. We present an experimental study on the combined effect of the laser pulse duration, pulse shape, and frequency chirp on the electron injection and acceleration process and the associated radiation emission for two different gas types—a 97.5% He and 2.5% N2 mixture and pure He. In general, the shortest pulse duration with minimal frequency chirp produced the highest energy electrons and the most charge. Pulses on the positive chirp side sustained electron injection and produced higher charge, but lower peak energy electrons, compared with negatively chirped pulses. A similar trend was observed for the radiant energy. The relationship between the radiant energy and the electron charge remained linear over a threefold change in the electron density and was independent of the drive pulse characteristics. X-ray spectra showed that ionization injection of electrons into the wakefield generally produced more photons than self-injection for all pulse durations/frequency chirp and had less of a spread in the number of photons around the peak x-ray energy.

  17. Characterization of x-ray framing cameras for the National Ignition Facility using single photon pulse height analysis

    Science.gov (United States)

    Holder, J. P.; Benedetti, L. R.; Bradley, D. K.

    2016-11-01

    Single hit pulse height analysis is applied to National Ignition Facility x-ray framing cameras to quantify gain and gain variation in a single micro-channel plate-based instrument. This method allows the separation of gain from detectability in these photon-detecting devices. While pulse heights measured by standard-DC calibration methods follow the expected exponential distribution at the limit of a compound-Poisson process, gain-gated pulse heights follow a more complex distribution that may be approximated as a weighted sum of a few exponentials. We can reproduce this behavior with a simple statistical-sampling model.

  18. Synchrotron radiation and free-electron lasers principles of coherent X-ray generation

    CERN Document Server

    Kim, Kwang-Je; Lindberg, Ryan

    2017-01-01

    Learn about the latest advances in high-brightness X-ray physics and technology with this authoritative text. Drawing upon the most recent theoretical developments, pre-eminent leaders in the field guide readers through the fundamental principles and techniques of high-brightness X-ray generation from both synchrotron and free-electron laser sources. A wide range of topics is covered, including high-brightness synchrotron radiation from undulators, self-amplified spontaneous emission, seeded high-gain amplifiers with harmonic generation, ultra-short pulses, tapering for higher power, free-electron laser oscillators, and X-ray oscillator and amplifier configuration. Novel mathematical approaches and numerous figures accompanied by intuitive explanations enable easy understanding of key concepts, whilst practical considerations of performance-improving techniques and discussion of recent experimental results provide the tools and knowledge needed to address current research problems in the field. This is a comp...

  19. A portable high-field pulsed-magnet system for single-crystal x-ray scattering studies.

    Science.gov (United States)

    Islam, Zahirul; Ruff, Jacob P C; Nojiri, Hiroyuki; Matsuda, Yasuhiro H; Ross, Kathryn A; Gaulin, Bruce D; Qu, Zhe; Lang, Jonathan C

    2009-11-01

    We present a portable pulsed-magnet system for x-ray studies of materials in high magnetic fields (up to 30 T). The apparatus consists of a split-pair of minicoils cooled on a closed-cycle cryostat, which is used for x-ray diffraction studies with applied field normal to the scattering plane. A second independent closed-cycle cryostat is used for cooling the sample to near liquid helium temperatures. Pulsed magnetic fields (approximately 1 ms in total duration) are generated by discharging a configurable capacitor bank into the magnet coils. Time-resolved scattering data are collected using a combination of a fast single-photon counting detector, a multichannel scaler, and a high-resolution digital storage oscilloscope. The capabilities of this instrument are used to study a geometrically frustrated system revealing strong magnetostrictive effects in the spin-liquid state.

  20. SMALL VOLUME LONG PULSE X RAY PREIONISED XeCl LASER WITH DOUBLE DISCHARGE AND FAST FERRITE MAGNETIC SWITCH

    OpenAIRE

    J. Hueber; Kobhio, M.; Fontaine, B.; Delaporte, Ph.; Sentis, M.; Forestier, B.

    1991-01-01

    Experimental results obtained with a high efficiency small volume long pulse X-Ray preionised XeCl laser with double discharge and very fast ferrite magnetic switch are presented and compared with the results given by a new XeCl laser numerical self consistant model. The model takes into account most recent kinetic data and time variation of discharge impedence and switch inductance. There is a good agreement between experiment and model on electrical and laser parameters for typical conditions.

  1. Double core-hole spectroscopy of transient plasmas produced in the interaction of ultraintense x-ray pulses with neon

    CERN Document Server

    Gao, Cheng; Yuan, Jianmin

    2015-01-01

    Double core-hole (DCH) spectroscopy is investigated systematically for neon atomic system in the interaction with ultraintense x-ray pulses with photon energy from 937 eV to 2000 eV. A time-dependent rate equation, implemented in the detailed level accounting approximation, is utilized to study the dynamical evolution of the level population and emission properties of the highly transient plasmas. For x-ray pulses with photon energy in the range of 937-1030 eV, where $1s\\rightarrow 2p$ resonance absorption from single core-hole (SCH) states of neon charge states exist, inner-shell resonant absorption (IRA) effects play important roles in the time evolution of population and DCH spectroscopy. Such IRA physical effects are illustrated in detail by investigating the interaction of x-ray pulses at a photon energy of 944 eV, which corresponds to the $1s\\rightarrow 2p$ resonant absorption from the SCH states ($1s2s^22p^4$, $1s2s2p^5$ and $1s2p^6$) of Ne$^{3+}$. After averaging over the space and time distribution o...

  2. FY05 LDRD Final ReportTime-Resolved Dynamic Studies using Short Pulse X-Ray Radiation

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, A; Dunn, J; van Buuren, T; Budil, K; Sadigh, B; Gilmer, G; Falcone, R; Lee, R; Ng, A

    2006-02-10

    Established techniques must be extended down to the ps and sub-ps time domain to directly probe product states of materials under extreme conditions. We used short pulse ({le} 1 ps) x-ray radiation to track changes in the physical properties in tandem with measurements of the atomic and electronic structure of materials undergoing fast laser excitation and shock-related phenomena. The sources included those already available at LLNL, including the picosecond X-ray laser as well as the ALS Femtosecond Phenomena beamline and the SSRL based sub-picosecond photon source (SPPS). These allow the temporal resolution to be improved by 2 orders of magnitude over the current state-of-the-art, which is {approx} 100 ps. Thus, we observed the manifestations of dynamical processes with unprecedented time resolution. Time-resolved x-ray photoemission spectroscopy and x-ray scattering were used to study phase changes in materials with sub-picosecond time resolution. These experiments coupled to multiscale modeling allow us to explore the physics of materials in high laser fields and extreme non-equilibrium states of matter. The ability to characterize the physical and electronic structure of materials under extreme conditions together with state-of-the-art models and computational facilities will catapult LLNL's core competencies into the scientific world arena as well as support its missions of national security and stockpile stewardship.

  3. Soft x-ray generation in gases by means of a pulsed electron beam produced in a high-voltage barier discharge

    NARCIS (Netherlands)

    Azarov, A.V.; Peters, P.J.M.; Boller, K.-J.

    2007-01-01

    A large area pulsed electron beam is produced by a high-voltage barrier discharge. We compare the properties of the x-rays generated by stopping this beam of electrons in a thin metal foil with those generated by stopping the electrons directly in various gases. The generation of x-rays was investig

  4. Improvement in limit of detection in particle induced X-ray emission by means of rise time and pulse shape discrimination

    Science.gov (United States)

    Papp, Tibor; Lakatos, Tamás; Nejedly, Zdenek; Campbell, John L.

    2002-04-01

    A digital signal processor, based upon high-rate sampling of the preamplifier output, and equipped with rise time and pulse shape discrimination, has been tested in three situations. This processor provided significant improvement of particle induced X-ray emission and X-ray fluorescence detection limits over the state of the art analog processors, depending on the energy and intensity distribution of the X-ray spectra. Additionally it had a superior performance when measurements were performed in an environment of large electronic noise and in large nuclear background environment. It has also improved the reduction of several artifacts in X-ray spectra.

  5. Improvement in limit of detection in particle induced X-ray emission by means of rise time and pulse shape discrimination

    Energy Technology Data Exchange (ETDEWEB)

    Papp, Tibor E-mail: tibpapp@netscape.nettibpapp@yahoo.ca; Lakatos, Tamas; Nejedly, Zdenek; Campbell, John L

    2002-04-01

    A digital signal processor, based upon high-rate sampling of the preamplifier output, and equipped with rise time and pulse shape discrimination, has been tested in three situations. This processor provided significant improvement of particle induced X-ray emission and X-ray fluorescence detection limits over the state of the art analog processors, depending on the energy and intensity distribution of the X-ray spectra. Additionally it had a superior performance when measurements were performed in an environment of large electronic noise and in large nuclear background environment. It has also improved the reduction of several artifacts in X-ray spectra.

  6. Resonant soft X-ray emission and X-ray absorption studies on Ga{sub 1-x}Mn{sub x}N grown by pulsed laser deposition

    Energy Technology Data Exchange (ETDEWEB)

    Krishnamurthy, Satheesh [School of Physics, Trinity College Dublin, College Green, Dublin 2 (Ireland); School of Physical Sciences, Dublin City University, Glasnevin, Dublin 9 (Ireland); Kennedy, Brian; McGee, Fintan; Venkatesan, M.; Coey, J.M.D.; Lunney, James G.; McGuinness, Cormac [School of Physics, Trinity College Dublin, College Green, Dublin 2 (Ireland); Learmonth, Timothy; Smith, Kevin E. [Department of Physilightlycs, Boston University, 590 Commonwealth Avenue, MA 02215 (United States); Schmitt, Thorsten [Swiss Light Source, Paul Scherrer Institut, 5232 Villigen PSI (Switzerland)

    2011-05-15

    In this study thin film samples of Ga{sub 1-x}Mn{sub x}N were grown by pulsed laser deposition on Al{sub 2}O{sub 3} (0001) substrates. X-ray diffraction measurements have confirmed these thin films exhibit hexagonal wurtzite structure. SQUID measurements show room temperature ferromagnetism of these dilute magnetic semiconductors (DMS). The techniques of X-ray absorption and soft X-ray emission spectroscopy at the N K-edge were used to study the changes in the unoccupied and occupied N 2p partial density of states respectively as a function of dopant concentration. These element and site specific spectroscopies allow us to characterise the electronic structure of these doped materials and reveal the influence of the Mn doping on the valence band as measured through the N 2p partial density of states. X-ray absorption measurements at the Mn L-edge confirm significant substitutional doping of Mn into Ga-sites. Finally, measurements of heavily Mn-doped films using both soft X-ray absorption and resonant soft X-ray emission at the N K edge reveal the presence of trapped molecular nitrogen. The trapped molecular nitrogen may be due to the high instantaneous deposition rate in the PLD process for these samples (copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  7. Radiography using a dense plasma focus device as a source of pulsed X-rays

    Science.gov (United States)

    Herrera, Julio; Castillo, Fermín; Gamboa, Isabel; Rangel, José

    2007-11-01

    Soft and hard X-ray emissions have been studied in the FN-II, which is a small dense plasma focus machine (5 kJ), operating at the Instituto de Ciencias Nucleares, UNAM, using aluminum filtered pin-hole cameras. Their angular distribution has been measured using TLD-200 dosimeters [1]. Their temporal evolution has been observed by means of a PIN diode, and scinltillators coupled to photomultipliers outside the discharge chamber. The X rays source can be concentrated by placing a needle on the end of the electrode. X-rays crossing across a 300 micron aluminum window, through the axis of the machine, can be used to obtain high contrast radiographs, with an average dose of 0.4 mGy per shot. In contrast, the average dose with a hollow cathode is 0.2 mGy per shot. This work is partially supported by grant IN105705 de la DGAPA-UNAM. [1] F. Castillo, J.J.E. Herrera, J. Rangel, I. Gamboa, G. Espinosa y J.I. Golzarri ``Angular Distribution of fusion products and X-rays emitted by a small dense plasma focus machine'' Journal of Applied Physics 101 013303-1-7 (2007).

  8. Coherent diffraction imaging analysis of shape-controlled nanoparticles with focused hard X-ray free-electron laser pulses.

    Science.gov (United States)

    Takahashi, Yukio; Suzuki, Akihiro; Zettsu, Nobuyuki; Oroguchi, Tomotaka; Takayama, Yuki; Sekiguchi, Yuki; Kobayashi, Amane; Yamamoto, Masaki; Nakasako, Masayoshi

    2013-01-01

    We report the first demonstration of the coherent diffraction imaging analysis of nanoparticles using focused hard X-ray free-electron laser pulses, allowing us to analyze the size distribution of particles as well as the electron density projection of individual particles. We measured 1000 single-shot coherent X-ray diffraction patterns of shape-controlled Ag nanocubes and Au/Ag nanoboxes and estimated the edge length from the speckle size of the coherent diffraction patterns. We then reconstructed the two-dimensional electron density projection with sub-10 nm resolution from selected coherent diffraction patterns. This method enables the simultaneous analysis of the size distribution of synthesized nanoparticles and the structures of particles at nanoscale resolution to address correlations between individual structures of components and the statistical properties in heterogeneous systems such as nanoparticles and cells.

  9. 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.

  10. Progress in compact soft x-ray lasers and their applications

    Energy Technology Data Exchange (ETDEWEB)

    Suckewer, S.; Skinner, C.H.

    1995-01-01

    The ultra-high brightness and short pulse duration of soft x-ray lasers provide unique advantages for novel applications. A crucial factor in the availability of these devices is their scale and cost. Recent breakthroughs in this field has brought closer the advent of table-top devices, suitable for applications to fields such as x-ray microscopy, chemistry, material science, plasma diagnostics, and lithography. In this article we review recent progress in the development of compact (table-top) soft x-ray lasers.

  11. Solidification of Al Alloys Under Electromagnetic Pulses and Characterization of the 3D Microstructures Using Synchrotron X-ray Tomography

    Science.gov (United States)

    Manuwong, Theerapatt; Zhang, Wei; Kazinczi, Peter Lobo; Bodey, Andrew J.; Rau, Christoph; Mi, Jiawei

    2015-07-01

    A novel programmable electromagnetic pulse device was developed and used to study the solidification of Al-15 pct Cu and Al-35 pct Cu alloys. The pulsed magnetic fluxes and Lorentz forces generated inside the solidifying melts were simulated using finite element methods, and their effects on the solidification microstructures were characterized using electron microscopy and synchrotron X-ray tomography. Using a discharging voltage of 120 V, a pulsed magnetic field with the peak Lorentz force of ~1.6 N was generated inside the solidifying Al-Cu melts which were showed sufficiently enough to disrupt the growth of the primary Al dendrites and the Al2Cu intermetallic phases. The microstructures exhibit a strong correlation to the characteristics of the applied pulse, forming a periodical pattern that resonates the frequency of the applied electromagnetic field.

  12. A New Possibility for Production of Sub-picosecond X-ray Pulses using a Time Dependent Radio Frequency Orbit Deflection

    Energy Technology Data Exchange (ETDEWEB)

    Zholents, A. A. [Argonne National Lab. (ANL), Argonne, IL (United States)

    2015-05-01

    It is shown that two radio frequency deflecting cavities with slightly different frequencies can be used to produce time-dependent orbit deflection to a few special electron bunches while keeping the majority of the electron bunches unaffected. These special bunches produce an x-ray pulse in which transverse position or angle, or both, are correlated with time. The x-ray pulses are then shortened, either with an asymmetrically cut crystal that acts as a pulse compressor, or with an angular aperture such as a narrow slit positioned downstream. The implementation of this technique creates a highly flexible environment for synchrotrons in which users of most beamlines will be able to easily select between the x-rays originated by the standard electron bunches and the short x-ray pulses originated by the special electron bunches carrying a time-dependent transverse correlation.

  13. Generation of Bright Isolated Attosecond Soft X-Ray Pulses Driven by Multi-Cycle Mid-Infrared Lasers

    CERN Document Server

    Chen, M -C; Mancuso, C; Dollar, F; Galloway, B; Popmintchev, D; Huang, P -C; Walker, B; Plaja, L; Jaron-Becker, A; Becker, A; Popmintchev, T; Murnane, M M; Kapteyn, H C

    2014-01-01

    High harmonic generation driven by femtosecond lasers makes it possible to capture the fastest dynamics in molecules and materials. However, to date the shortest attosecond (as) pulses have been produced only in the extreme ultraviolet (EUV) region of the spectrum below 100 eV, which limits the range of materials and molecular systems that can be explored. Here we use advanced experiment and theory to demonstrate a remarkable convergence of physics: when mid-infrared lasers are used to drive the high harmonic generation process, the conditions for optimal bright soft X-ray generation naturally coincide with the generation of isolated attosecond pulses. The temporal window over which phase matching occurs shrinks rapidly with increasing driving laser wavelength, to the extent that bright isolated attosecond pulses are the norm for 2 \\mu m driving lasers. Harnessing this realization, we demonstrate the generation of isolated soft X-ray attosecond pulses at photon energies up to 180 eV for the first time, that e...

  14. Nonlinear coherent Thomson scattering from relativistic electron sheets as a means to produce isolated ultrabright attosecond x-ray pulses

    Directory of Open Access Journals (Sweden)

    H.-C. Wu (武慧春

    2011-07-01

    Full Text Available A new way to generate intense attosecond x-ray pulses is discussed. It relies on coherent Thomson scattering (CTS from relativistic electron sheets. A double layer technique is used to generate planar solid-density sheets of monochromatic high-γ electrons with zero transverse momentum such that coherently backscattered light is frequency upshifted by factors up to 4γ^{2}. Here previous work [H.-C. Wu et al., Phys. Rev. Lett. 104, 234801 (2010PRLTAO0031-900710.1103/PhysRevLett.104.234801] is extended to the regime of high-intensity probe light with normalized amplitude a_{0}>1 leading to nonlinear CTS effects such as pulse contraction and steepening. The results are derived both by particle-in-cell (PIC simulation in a boosted frame and by analytic theory. PIC simulation shows that powerful x-ray pulses (1 keV, 10   gigawatt can be generated. They call for experimental verification. Required prerequisites such as manufacture of nanometer-thick target foils is ready and ultrahigh contrast laser pulses should be within reach in the near future.

  15. Modeling of collisional excited x-ray lasers using short pulse laser pumping

    Energy Technology Data Exchange (ETDEWEB)

    Sasaki, Akira; Moribayashi, Kengo; Utsumi, Takayuki; Tajima, Toshiki [Japan Atomic Energy Research Inst., Neyagawa, Osaka (Japan). Kansai Research Establishment

    1998-03-01

    A simple atomic kinetics model of electron collisional excited x-ray lasers has been developed. The model consists of a collisional radiative model using the average ion model (AIM) and a detailed term accounting (DTA) model of Ni-like Ta. An estimate of plasma condition to produce gain in Ni-like Ta ({lambda}=44A) is given. Use of the plasma confined in a cylinder is proposed to preform a uniform high density plasma from 1-D hydrodynamics calculations. (author)

  16. Radio pulse search and X-Ray monitoring of SAX J1808.4-3658: What Causes its Orbital Evolution?

    CERN Document Server

    Patruno, Alessandro; Kuiper, Lucien; Bult, Peter; Hessels, Jason; Knigge, Christian; King, Andrew R; Wijnands, Rudy; van der Klis, Michiel

    2016-01-01

    The accreting millisecond X-ray pulsar (AMXP) SAX J1808.4-3658, shows a peculiar orbital evolution that proceeds at a much faster pace than predicted by conservative binary evolution models. It is important to identify the underlying mechanism responsible for this behavior because it can help to understand how this system evolves. It has also been suggested that, when in quiescence, SAX J1808.4-3658 turns on as a radio pulsar, a circumstance that might provide a link between AMXPs and black-widow radio pulsars. In this work we report the results of a deep radio pulsation search at 2 GHz using the Green Bank Telescope in August 2014 and an X-ray monitoring of the 2015 outburst with Chandra, Swift, and INTEGRAL. In particular, we present the X-ray timing analysis of a 30-ks Chandra observation executed during the 2015 outburst. We detect no radio pulsations, and place the strongest limit to date on the pulsed radio flux density of any AMXP. We also find that the orbit of SAX J1808.4-3658 continues evolving at a...

  17. Scheme for generation of fully-coherent, TW power level hard X-ray pulses from baseline undulators at the European X-ray FEL

    CERN Document Server

    Geloni, Gianluca; Saldin, Evgeni

    2010-01-01

    The most promising way to increase the output power of an X-ray FEL (XFEL) is by tapering the magnetic field of the undulator. Also, significant increase in power is achievable by starting the FEL process from a monochromatic seed rather than from noise. This report proposes to make use of a cascade self-seeding scheme with wake monochromators in a tunable-gap baseline undulator at the European XFEL to create a source capable of delivering coherent radiation of unprecedented characteristics at hard X-ray wavelengths. Compared with SASE X-ray FEL parameters, the radiation from the new source has three truly unique aspects: complete longitudinal and transverse coherence, and a peak brightness three orders of magnitude higher than what is presently available at LCLS. Additionally, the new source will generate hard X-ray beam at extraordinary peak (TW) and average (kW) power level. The proposed source can thus revolutionize fields like single biomolecule imaging, inelastic scattering and nuclear resonant scatteri...

  18. Structure of isolated biomolecules obtained from ultrashort x-ray pulses: exploiting the symmetry of random orientations.

    Science.gov (United States)

    Saldin, D K; Shneerson, V L; Fung, R; Ourmazd, A

    2009-04-01

    Amongst the promised capabilities of fourth-generation x-ray sources currently under construction is the ability to record diffraction patterns from individual biological molecules. One version of such an experiment would involve directing a stream of molecules into the x-ray beam and sequentially recording the scattering from each molecule of a short, but intense, pulse of radiation. The pulses are sufficiently short that the diffraction pattern is that due to scattering from identical molecules 'frozen' in random orientations. Each diffraction pattern may be thought of as a section through the 3D reciprocal space of the molecule, of unknown, random, orientation. At least two algorithms have been proposed for finding the relative orientations from just the measured diffraction data. The 'common-line' method, also employed in 3D electron microscopy, appears not best suited to the very low mean photon count per diffraction pattern pixel expected in such experiments. A manifold embedding technique has been used to reconstruct the 3D diffraction volume and hence the electron density of a small protein at the signal level expected of the scattering of an x-ray free electron laser pulse from a 500 kD biomolecule. In this paper, we propose an alternative algorithm which raises the possibility of reconstructing the 3D diffraction volume of a molecule without determining the relative orientations of the individual diffraction patterns. We discuss why such an algorithm may provide a practical and computationally convenient method of extracting information from very weak diffraction patterns. We suggest also how such a method may be adapted to the problem of finding the variations of a structure with time in a time-resolved pump-probe experiment.

  19. Single-shot 3D structure determination of nanocrystals with femtosecond X-ray free electron laser pulses

    CERN Document Server

    Xu, Rui; Song, Changyong; Rodriguez, Jose A; Huang, Zhifeng; Chen, Chien-Chun; Nam, Daewoong; Park, Jaehyun; Gallagher-Jones, Marcus; Kim, Sangsoo; Kim, Sunam; Suzuki, Akihiro; Takayama, Yuki; Oroguchi, Tomotaka; Takahashi, Yukio; Fan, Jiadong; Zou, Yunfei; Hatsui, Takaki; Inubushi, Yuichi; Kameshima, Takashi; Yonekura, Koji; Tono, Kensuke; Togashi, Tadashi; Sato, Takahiro; Yamamoto, Masaki; Nakasako, Masayoshi; Yabashi, Makina; Ishikawa, Tetsuya; Miao, Jianwei

    2013-01-01

    Coherent diffraction imaging (CDI) using synchrotron radiation, X-ray free electron lasers (X-FELs), high harmonic generation, soft X-ray lasers, and optical lasers has found broad applications across several disciplines. An active research direction in CDI is to determine the structure of single particles with intense, femtosecond X-FEL pulses based on diffraction-before-destruction scheme. However, single-shot 3D structure determination has not been experimentally realized yet. Here we report the first experimental demonstration of single-shot 3D structure determination of individual nanocrystals using ~10 femtosecond X-FEL pulses. Coherent diffraction patterns are collected from high-index-faceted nanocrystals, each struck by a single X-FEL pulse. Taking advantage of the symmetry of the nanocrystal, we reconstruct the 3D structure of each nanocrystal from a single-shot diffraction pattern at ~5.5 nm resolution. As symmetry exists in many nanocrystals and virus particles, this method can be applied to 3D st...

  20. Investigations on femtosecond-pulse-driven soft X-ray lasers using a gas puff target irradiated with a Ti:sapphire laser

    Energy Technology Data Exchange (ETDEWEB)

    Fiedorowicz, H.; Bartnik, A.; Szczurek, M. [Military Univ. of Technology, Warsaw (Poland). Inst. of Optoelectronics; Mocek, T.; Shin, H.J.; Cha, Y.H.; Lee, D.G.; Hong, K.H.; Nam, C.H. [Military Univ. of Technology, Warsaw (Poland). Inst. of Optoelectronics; Korea Advanced Inst. of Science and Technology, Taejon (Korea). Dept. of Physics

    2001-07-01

    Experimental investigations on soft X-ray lasers based on optical field ionization of gases with an ultrashort-pulse terawatt laser system are presented. The X-ray laser active medium was created using an elongated gas puff target formed by pulsed injection of a small amount of gas from a high-pressure electromagnetic valve through a nozzle in the form of a slit. The target was irradiated with a laser pulses from a 20-fs. 50-mJ Ti:Sapphire (Ti:S) laser system. Both recombination and collisional soft X-ray laser scheme have been studied. Soft X-ray spectra from nitrogen, oxygen, and xenon targets are presented and discussed. (orig.)

  1. A High-Energy, Ultrashort-Pulse X-Ray System for the Dynamic Study of Heavy, Dense Materials

    Energy Technology Data Exchange (ETDEWEB)

    Gibson, David Jeremy [Univ. of California, Davis, CA (United States)

    2004-01-01

    Thomson-scattering based x-ray radiation sources, in which a laser beam is scattered off a relativistic electron beam resulting in a high-energy x-ray beam, are currently being developed by several groups around the world to enable studies of dynamic material properties which require temporal resolution on the order of tens of femtoseconds to tens of picoseconds. These sources offer pulses that are shorter than available from synchrotrons, more tunable than available from so-called Ka sources, and more penetrating and more directly probing than ultrafast lasers. Furthermore, Thomson-scattering sources can scale directly up to x-ray energies in the few MeV range, providing peak brightnesses far exceeding any other sources in this regime. This dissertation presents the development effort of one such source at Lawrence Livermore National Laboratory, the Picosecond Laser-Electron InterAction for the Dynamic Evaluation of Structures (PLEIADES) project, designed to target energies from 30 keV to 200 keV, with a peak brightness on the order of 1018 photons • s-1 • mm-2 • mrad-2 • 0.01% bandwidth-1. A 10 TW Ti:Sapphire based laser system provides the photons for the interaction, and a 100 MeV accelerator with a 1.6 cell S-Band photoinjector at the front end provides the electron beam. The details of both these systems are presented, as is the initial x-ray production and characterization, validating the theory of Thomson scattering. In addition to the systems used to enable PLEIADES, two alternative systems are discussed. An 8.5 GHz X-Band photoinjector, capable of sustaining higher accelerating gradients and producing lower emittance electron beams in a smaller space than the S-Band gun, is presented, and the initial operation and commissioning of this gun is presented. Also, a hybrid chirped-pulse amplification system is presented as an alternative to the standard regenerative amplifier technology in high

  2. Construction of a magnetic bottle spectrometer and its application to pulse duration measurement of X-ray laser using a pump-probe method

    Directory of Open Access Journals (Sweden)

    S. Namba

    2015-11-01

    Full Text Available To characterize the temporal evolution of ultrashort X-ray pulses emitted by laser plasmas using a pump-probe method, a magnetic bottle time-of-flight electron spectrometer is constructed. The design is determined by numerical calculations of a mirror magnetic field and of the electron trajectory in a flight tube. The performance of the spectrometer is characterized by measuring the electron spectra of xenon atoms irradiated with a laser-driven plasma X-ray pulse. In addition, two-color above-threshold ionization (ATI experiment is conducted for measurement of the X-ray laser pulse duration, in which xenon atoms are simultaneously irradiated with an X-ray laser pump and an IR laser probe. The correlation in the intensity of the sideband spectra of the 4d inner-shell photoelectrons and in the time delay of the two laser pulses yields an X-ray pulse width of 5.7 ps, in good agreement with the value obtained using an X-ray streak camera.

  3. An innovative method to reduce count loss from pulse pile-up in a photon-counting pixel for high flux X-ray applications

    Science.gov (United States)

    Lee, D.; Lim, K.; Park, K.; Lee, C.; Alexander, S.; Cho, G.

    2017-03-01

    In this study, an innovative fast X-ray photon-counting pixel for high X-ray flux applications is proposed. A computed tomography system typically uses X-ray fluxes up to 108 photons/mm2/sec at the detector and thus a fast read-out is required in order to process individual X-ray photons. Otherwise, pulse pile-up can occur at the output of the signal processing unit. These superimposed signals can distort the number of incident X-ray photons leading to count loss. To minimize such losses, a cross detection method was implemented in the photon-counting pixel. A maximum count rate under X-ray tube voltage of 90 kV was acquired which reflect electrical test results of the proposed photon counting pixel. A maximum count of 780 kcps was achieved with a conventional photon-counting pixel at the pulse processing time of 500 ns, which is the time for a pulse to return to the baseline from the initial rise. In contrast, the maximum count of about 8.1 Mcps was achieved with the proposed photon-counting pixel. From these results, it was clear that the maximum count rate was increased by approximately a factor 10 times by adopting the cross detection method. Therefore, it is an innovative method to reduce count loss from pulse pile-up in a photon-counting pixel while maintaining the pulse processing time.

  4. Subfemtosecond X-ray Pulses Produced Directly by High Harmonic Generation

    Institute of Scientific and Technical Information of China (English)

    WANG Ying-Song; XU Zhi-Zhan

    2000-01-01

    The generation of subfemtosecond pulses in hydrogen-like atoms through high-harmonic generation by using superintense multicycle driver pulses is numerically investigated. It is shown that a single subfemtosecond pulse can be directly generated when the driver pulse is strong enough to deplete the neutral atoms within several optical cycles. The propagation effect is neglected during the numerical examinations.

  5. Energy spectrum measurement of high power and high energy(6 and 9 MeV) pulsed x-ray source for industrial use

    Energy Technology Data Exchange (ETDEWEB)

    Takagi, Hiroyuki [Hitachi, Ltd. Power Systems Company, Ibaraki (Japan); Murata, Isao [Graduate School of Engineering, Osaka University, Osaka (Japan)

    2016-06-15

    Industrial X-ray CT system is normally applied to non-destructive testing (NDT) for industrial product made from metal. Furthermore there are some special CT systems, which have an ability to inspect nuclear fuel assemblies or rocket motors, using high power and high energy (more than 6 MeV) pulsed X-ray source. In these case, pulsed X-ray are produced by the electron linear accelerator, and a huge number of photons with a wide energy spectrum are produced within a very short period. Consequently, it is difficult to measure the X-ray energy spectrum for such accelerator-based X-ray sources using simple spectrometry. Due to this difficulty, unexpected images and artifacts which lead to incorrect density information and dimensions of specimens cannot be avoided in CT images. For getting highly precise CT images, it is important to know the precise energy spectrum of emitted X-rays. In order to realize it we investigated a new approach utilizing the Bayesian estimation method combined with an attenuation curve measurement using step shaped attenuation material. This method was validated by precise measurement of energy spectrum from a 1 MeV electron accelerator. In this study, to extend the applicable X-ray energy range we tried to measure energy spectra of X-ray sources from 6 and 9 MeV linear accelerators by using the recently developed method. In this study, an attenuation curves are measured by using a step-shaped attenuation materials of aluminum and steel individually, and the each X-ray spectrum is reconstructed from the measured attenuation curve by the spectrum type Bayesian estimation method. The obtained result shows good agreement with simulated spectra, and the presently developed technique is adaptable for high energy X-ray source more than 6 MeV.

  6. Single-pulse enhanced coherent diffraction imaging of bacteria with an X-ray free-electron laser

    Science.gov (United States)

    Fan, Jiadong; Sun, Zhibin; Wang, Yaling; Park, Jaehyun; Kim, Sunam; Gallagher-Jones, Marcus; Kim, Yoonhee; Song, Changyong; Yao, Shengkun; Zhang, Jian; Zhang, Jianhua; Duan, Xiulan; Tono, Kensuke; Yabashi, Makina; Ishikawa, Tetsuya; Fan, Chunhai; Zhao, Yuliang; Chai, Zhifang; Gao, Xueyun; Earnest, Thomas; Jiang, Huaidong

    2016-09-01

    High-resolution imaging offers one of the most promising approaches for exploring and understanding the structure and function of biomaterials and biological systems. X-ray free-electron lasers (XFELs) combined with coherent diffraction imaging can theoretically provide high-resolution spatial information regarding biological materials using a single XFEL pulse. Currently, the application of this method suffers from the low scattering cross-section of biomaterials and X-ray damage to the sample. However, XFELs can provide pulses of such short duration that the data can be collected using the “diffract and destroy” approach before the effects of radiation damage on the data become significant. These experiments combine the use of enhanced coherent diffraction imaging with single-shot XFEL radiation to investigate the cellular architecture of Staphylococcus aureus with and without labeling by gold (Au) nanoclusters. The resolution of the images reconstructed from these diffraction patterns were twice as high or more for gold-labeled samples, demonstrating that this enhancement method provides a promising approach for the high-resolution imaging of biomaterials and biological systems.

  7. Single-pulse enhanced coherent diffraction imaging of bacteria with an X-ray free-electron laser

    Science.gov (United States)

    Fan, Jiadong; Sun, Zhibin; Wang, Yaling; Park, Jaehyun; Kim, Sunam; Gallagher-Jones, Marcus; Kim, Yoonhee; Song, Changyong; Yao, Shengkun; Zhang, Jian; Zhang, Jianhua; Duan, Xiulan; Tono, Kensuke; Yabashi, Makina; Ishikawa, Tetsuya; Fan, Chunhai; Zhao, Yuliang; Chai, Zhifang; Gao, Xueyun; Earnest, Thomas; Jiang, Huaidong

    2016-01-01

    High-resolution imaging offers one of the most promising approaches for exploring and understanding the structure and function of biomaterials and biological systems. X-ray free-electron lasers (XFELs) combined with coherent diffraction imaging can theoretically provide high-resolution spatial information regarding biological materials using a single XFEL pulse. Currently, the application of this method suffers from the low scattering cross-section of biomaterials and X-ray damage to the sample. However, XFELs can provide pulses of such short duration that the data can be collected using the “diffract and destroy” approach before the effects of radiation damage on the data become significant. These experiments combine the use of enhanced coherent diffraction imaging with single-shot XFEL radiation to investigate the cellular architecture of Staphylococcus aureus with and without labeling by gold (Au) nanoclusters. The resolution of the images reconstructed from these diffraction patterns were twice as high or more for gold-labeled samples, demonstrating that this enhancement method provides a promising approach for the high-resolution imaging of biomaterials and biological systems. PMID:27659203

  8. Ultrafast atomic process in X-ray emission by using inner-shell ionization method for sodium and carbon atoms

    Energy Technology Data Exchange (ETDEWEB)

    Moribayashi, Kengo; Sasaki, Akira; Tajima, Toshiki [Japan Atomic Energy Research Inst., Neyagawa, Osaka (Japan). Kansai Research Establishment

    1998-07-01

    An ultrafast inner-shell ionization process with X-ray emission stimulated by high-intensity short-pulse X-ray is studied. Carbon and sodium atoms are treated as target matter. It is shown that atomic processes of the target determine the necessary X-ray intensity for X-ray laser emission as well as the features of X-ray laser such as wavelength and duration time. The intensity also depends on the density of initial atoms. Furthermore, we show that as the intensity of X-ray source becomes high, the multi-inner-shell ionization predominates, leading to the formation of hollow atoms. As the density of hollow atoms is increased by the pumping X-ray power, the emission of X-rays is not only of significance for high brightness X-ray measurement but also is good for X-ray lasing. New classes of experiments of pump X-ray probe and X-ray laser are suggested. (author)

  9. 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 .

  10. 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.

  11. In-flight performance of pulse processing system of the ASTRO-H soft x-ray spectrometer

    Science.gov (United States)

    Ishisaki, Yoshitaka; Yamada, Shinya; Seta, Hiromi; Tashiro, Makoto S.; Takeda, Sawako; Terada, Yukikatsu; Kato, Yuka; Tsujimoto, Masahiro; Koyama, Shu; MItsuda, Kazuhisa; Sawada, Makoto; Boyce, Kevin R.; Chiao, Meng P.; Watanabe, Tomomi; Leutenegger, Maurice A.; Eckart, Megan E.; Porter, F. Scott; Kilbourne, Caroline A.; Kelley, Richard L.

    2016-07-01

    We summarize results of the initial in-orbit performance of the pulse shape processor (PSP) of the soft x-ray spectrometer instrument onboard ASTRO-H (Hitomi). Event formats, kind of telemetry, and the pulse processing parameters are described, and the parameter settings in orbit are listed. PSP was powered-on two days after launch, and the event threshold was lowered in orbit. PSP worked fine in orbit, and there were no memory error nor SpaceWire communication error until the break-up of spacecraft. Time assignment, electrical crosstalk, and the event screening criteria are studied. It is confirmed that the event processing rate at 100% CPU load is 200 c/s/array, compliant with the requirement on PSP.

  12. Generation of high-photon flux-coherent soft x-ray radiation with few-cycle pulses.

    Science.gov (United States)

    Demmler, Stefan; Rothhardt, Jan; Hädrich, Steffen; Krebs, Manuel; Hage, Arvid; Limpert, Jens; Tünnermann, Andreas

    2013-12-01

    We present a tabletop source of coherent soft x-ray radiation with high-photon flux. Two-cycle pulses delivered by a fiber-laser-pumped optical parametric chirped-pulse amplifier operating at 180 kHz repetition rate are upconverted via high harmonic generation in neon to photon energies beyond 200 eV. A maximum photon flux of 1.3·10(8) photons/s is achieved within a 1% bandwidth at 125 eV photon energy. This corresponds to a conversion efficiency of ~10(-9), which can be reached due to a gas jet simultaneously providing a high target density and phase matching. Further scaling potential toward higher photon flux as well as higher photon energies are discussed.

  13. Demonstration of a long pulse X-ray source at the National Ignition Facility

    Science.gov (United States)

    May, M. J.; Opachich, Y. P.; Kemp, G. E.; Colvin, J. D.; Barrios, M. A.; Widmann, K. W.; Fournier, K. B.; Hohenberger, M.; Albert, F.; Regan, S. P.

    2017-04-01

    A long duration high fluence x-ray source has been developed at the National Ignition Facility (NIF). The target was a 14.4 mm tall, 4.1 mm diameter, epoxy walled, gas filled pipe. Approximately 1.34 MJ from the NIF laser was used to heat the mixture of (55:45) Kr:Xe at 1.2 atm (˜5.59 mg/cm3) to emit in a fairly isotropic radiant intensity of 400-600 GW/sr from the Ephoton = 3-7 keV spectral range for a duration of ≈ 14 ns. The HYDRA simulated radiant intensities were in reasonable agreement with experiments but deviated at late times.

  14. Wakefield issue and its impact on X-ray photon pulse in the SXFEL test facility

    CERN Document Server

    Song, Minghao; Feng, Chao; Deng, Haixiao; Liu, Bo; Wang, Dong

    2015-01-01

    Besides the designed beam acceleration, the energy of electrons changed by the longitudinal wakefields in a real free-electron laser (FEL) facility, which may degrade FEL performances from the theoretical expectation. In this paper, with the help of simulation codes, the wakefields induced beam energy loss in the sophisticated undulator section is calculated for Shanghai soft X-ray FEL, which is a two-stage seeded FEL test facility. While the 1st stage 44 nm FEL output is almost not affected by the wakefields, it is found that a beam energy loss about 0.8 MeV degrades the peak brightness of the 2nd stage 8.8 nm FEL by a factor of 1.6, which however can be compensated by a magnetic field fine tuning of each undulator segment.

  15. The Physics and Applications of High Brightness Electron Beams

    Science.gov (United States)

    Palumbo, Luigi; Rosenzweig, J.; Serafini, Luca

    2007-09-01

    Plenary sessions. RF deflector based sub-Ps beam diagnostics: application to FEL and advanced accelerators / D. Alesini. Production of fermtosecond pulses and micron beam spots for high brightness electron beam applications / S.G. Anderson ... [et al.]. Wakefields of sub-picosecond electron bunches / K.L.F. Bane. Diamond secondary emitter / I. Ben-Zvi ... [et al.]. Parametric optimization for an X-ray free electron laser with a laser wiggler / R. Bonifacio, N. Piovella and M.M. Cola. Needle cathodes for high-brightness beams / C.H. Boulware ... [et al.]. Non linear evolution of short pulses in FEL cascaded undulators and the FEL harmonic cascade / L. Giannessi and P. Musumeci. High brightness laser induced multi-meV electron/proton sources / D. Giulietti ... [et al.]. Emittance limitation of a conditioned beam in a strong focusing FEL undulator / Z. Huang, G. Stupakov and S. Reiche. Scaled models: space-charge dominated electron storage rings / R.A. Kishek ... [et al.]. High brightness beam applications: energy recovered linacs / G.A. Krafft. Maximizing brightness in photoinjectors / C. Limborg-Deprey and H. Tomizawa. Ultracold electron sources / O.J. Luiten ... [et al.]. Scaling laws of structure-based optical accelerators / A. Mizrahi, V. Karagodsky and L. Schächter. High brightness beams-applications to free-electron lasers / S. Reiche. Conception of photo-injectors for the CTF3 experiment / R. Roux. Superconducting RF photoinjectors: an overview / J. Sekutowicz. Status and perspectives of photo injector developments for high brightness beams / F. Stephan. Results from the UCLA/FNLP underdense plasma lens experiment / M.C. Thompson ... [et al.]. Medical application of multi-beam compton scattering monochromatic tunable hard X-ray source / M. Uesaka ... [et al.]. Design of a 2 kA, 30 fs RF-photoinjector for waterbag compression / S.B. Van Der Geer, O.J. Luiten and M.J. De Loos. Proposal for a high-brightness pulsed electron source / M. Zolotorev ... [et al

  16. Experimental and numerical analysis of atmospheric air plasma induced by multi-MeV pulsed X-ray

    Science.gov (United States)

    Maulois, Mélissa; Ribière, Maxime; Eichwald, Olivier; Yousfi, Mohammed; Pouzalgues, Romain; Garrigues, Alain; Delbos, Christophe; Azaïs, Bruno

    2016-10-01

    Quantification of electromagnetic stresses on electronic systems, following irradiation of the air by ionizing radiations, requires a thorough study of the plasma generated. In this work, the temporal evolution of non-equilibrium air plasmas self-induced by energetic X-rays is experimentally and theoretically investigated at atmospheric pressure. Time resolved electron density measurements are based on transmission measurements of an electromagnetic wave in the microwave range. The electromagnetic wave is launched into a wave guide, which is irradiated by a high flux of multi-MeV pulsed X-rays. For different X-ray fluxes, the electron density is determined from the comparison between the transmitted microwave signal at the waveguide output, and the result of the calculation of the propagation of an electromagnetic wave through time varying plasma contained in a waveguide. These measurements require a priori assumptions on electron temperature, which is obtained and confirmed by a reaction kinetics model of the evolution of the electron energy and the densities of the different humid air plasma species inside the waveguide. The considered chemical kinetics scheme involves 39 influent species (electrons, positive ions, negative ions, and neutral atoms and molecules in their ground or metastable excited states) reacting following 265 selected reactions. A good agreement is observed between the calculated and measured time evolution of the transmitted signal for specific profiles of electron energy and density. In our experiments, the maximum electron density is of the order of few 1012 cm-3, for a mean electron energy of about 0.5 eV. For doses range from 3 Gy to 21 Gy, the discrepancies between the measurements and the model for the maximum of the electron density are within a factor of 2.

  17. High-Energy pulse profile of the Transient X-ray Pulsar SAX J2103.5+4545

    CERN Document Server

    Falanga, M; Burderi, L; Bonnet-Bidaud, J M; Goldoni, P; Goldwurm, A; Lavagetto, G; Iaria, R; Robba, N R

    2005-01-01

    In two recent INTEGRAL papers, Lutovinov et al. (2003) and Blay et al. (2004) report a timing and spectral analysis of the transient Be/X-ray pulsar SAX J2103.5+4545 at high energies (5--200 keV). In this work we present for the first time a study of the pulse profile at energies above 20 keV using INTEGRAL data. The spin-pulse profile shows a prominent (with a duty cycle of 14%) and broad (with a FWHM of ~ 51 s) peak and a secondary peak which becomes more evident above 20 keV. The pulsed fraction increases with energy from ~ 45% at 5--40 keV to ~ 80% at 40--80 keV. The morphology of the pulse profile also changes as a function of energy, consistent with variations in the spectral components that are visible in the pulse phase resolved spectra. A study of the double peaked profile shows that the difference in the two peaks can be modeled by a different scattering fraction between the radiation from the two magnetic poles.

  18. 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.

  19. The relationship between hard X-ray pulse timings and the locations of footpoint sources during solar flares

    CERN Document Server

    Inglis, A R; 10.1088/0004-637X/748/2/139

    2013-01-01

    The cause of quasi-periodic pulsations (QPP) in solar flares remains the subject of debate. Recently, Nakariakov & Zimovets (2011) proposed a new model suggesting that, in two-ribbon flares, such pulsations could be explained by propagating slow waves. These waves may travel obliquely to the magnetic field, reflect in the chromosphere and constructively interfere at a spatially separate site in the corona, leading to quasi-periodic reconnection events progressing along the flaring arcade. Such a slow wave regime would have certain observational characteristics. We search for evidence of this phenomenon during a selection of two-ribbon flares observed by RHESSI, SOHO and TRACE; the flares of 2002 November 9, 2005 January 19 and 2005 August 22. We were not able to observe a clear correlation between hard X-ray footpoint separations and pulse timings during these events. Also, the motion of hard X-ray footpoints is shown to be continuous within the observational error, whereas a discontinuous motion might be...

  20. Wakefield issue and its impact on X-ray photon pulse in the SXFEL test facility

    Science.gov (United States)

    Song, Minghao; Li, Kai; Feng, Chao; Deng, Haixiao; Liu, Bo; Wang, Dong

    2016-06-01

    Besides the designed beam acceleration, the energy of electrons is changed by the longitudinal wakefields in a real free-electron laser (FEL) facility, which may degrade FEL performances from the theoretical expectation. In this paper, with the help of simulation codes, the wakefields induced beam energy loss in the sophisticated undulator section is calculated for Shanghai soft X-ray FEL, which is a two-stage seeded FEL test facility. While the 1st stage 44 nm FEL output is almost not affected by the wakefields, it is found that a beam energy loss about 0.8 MeV degrades the peak brightness of the 2nd stage 8.8 nm FEL by a factor of 1.6, which however can be compensated by a magnetic field fine tuning of each undulator segment. And the longitudinal coherence of the 8.8 nm FEL output illustrates a slight degradation, because of the beam energy curvatures induced by the wakefields.

  1. Theoretical study of Ni-like Ag 13.9 nm TCE x-ray laser driven by two picosecond pulses

    Institute of Scientific and Technical Information of China (English)

    Qiao Xiu-Mei; Zhang Gou-Ping

    2007-01-01

    The Ni-like Ag 13.9 nm x-ray laser has been previously demonstrated that the higher gain near critical surface contributes little to the amplification of the x-ray laser because of severe refraction. In this paper, the transient collision excitation (TCE) Ni-like Ag 13.9 nm x-ray laser is simulated, driven by two 3ps short pulse preceded by a 330 ps long prepulse, optimization of the peak to peak delay time of the two short pulses is made to get the best results. Simulation indicates that by producing lowly ionized preplasma with smoothly varying electron density, it is possible to decrease electron density gradient in higher density region, and thus higher gains near this region could be utilized, and if the main short pulse is delayed by 900 ps, local gains where electron density larger than ~ 4 x 1020 cm-3 could be utilized.

  2. Analysis of 3D Prints by X-ray Computed Microtomography and Terahertz Pulsed Imaging

    DEFF Research Database (Denmark)

    Markl, Daniel; Zeitler, J Axel; Rasch, Cecilie

    2016-01-01

    PURPOSE: A 3D printer was used to realise compartmental dosage forms containing multiple active pharmaceutical ingredient (API) formulations. This work demonstrates the microstructural characterisation of 3D printed solid dosage forms using X-ray computed microtomography (XμCT) and terahertz pulsed...... imaging (TPI). METHODS: Printing was performed with either polyvinyl alcohol (PVA) or polylactic acid (PLA). The structures were examined by XμCT and TPI. Liquid self-nanoemulsifying drug delivery system (SNEDDS) formulations containing saquinavir and halofantrine were incorporated into the 3D printed...... was characterised by XμCT and TPI on the basis of the computer-aided design (CAD) models of the dosage form (compartmentalised PVA structures were 7.5 ± 0.75% larger than designed; n = 3). CONCLUSIONS: The 3D printer can reproduce specific structures very accurately, whereas the 3D prints can deviate from...

  3. Analysis of 3D Prints by X-ray Computed Microtomography and Terahertz Pulsed Imaging

    DEFF Research Database (Denmark)

    Markl, Daniel; Zeitler, J Axel; Rasch, Cecilie

    2017-01-01

    PURPOSE: A 3D printer was used to realise compartmental dosage forms containing multiple active pharmaceutical ingredient (API) formulations. This work demonstrates the microstructural characterisation of 3D printed solid dosage forms using X-ray computed microtomography (XμCT) and terahertz pulsed...... imaging (TPI). METHODS: Printing was performed with either polyvinyl alcohol (PVA) or polylactic acid (PLA). The structures were examined by XμCT and TPI. Liquid self-nanoemulsifying drug delivery system (SNEDDS) formulations containing saquinavir and halofantrine were incorporated into the 3D printed...... was characterised by XμCT and TPI on the basis of the computer-aided design (CAD) models of the dosage form (compartmentalised PVA structures were 7.5 ± 0.75% larger than designed; n = 3). CONCLUSIONS: The 3D printer can reproduce specific structures very accurately, whereas the 3D prints can deviate from...

  4. Very low electron temperature in warm dense matter formed by focused picosecond soft x-ray laser pulses

    Energy Technology Data Exchange (ETDEWEB)

    Ishino, Masahiko, E-mail: ishino.masahiko@jaea.go.jp; Hasegawa, Noboru; Nishikino, Masaharu; Kawachi, Tetsuya; Yamagiwa, Mitsuru [Quantum Beam Science Center, Japan Atomic Energy Agency, 8-1-7, Umemidai, Kizugawa, Kyoto 619-0215 (Japan); Pikuz, Tatiana [Joint Institute for High Temperatures, Russian Academy of Sciences, 13-2, Izhorskaya Street, Moscow 125412 (Russian Federation); Graduate School of Engineering, Osaka University, 1-1, Yamadaoka, Suita, Osaka 565-0871 (Japan); Skobelev, Igor [Joint Institute for High Temperatures, Russian Academy of Sciences, 13-2, Izhorskaya Street, Moscow 125412 (Russian Federation); National Research Nuclear University, Moscow Engineering Physics Institute, 31, Kashirskoe Shosse, Moscow 115409 (Russian Federation); Faenov, Anatoly [Joint Institute for High Temperatures, Russian Academy of Sciences, 13-2, Izhorskaya Street, Moscow 125412 (Russian Federation); Institute for Academic Initiatives, Osaka University, 1-1, Yamadaoka, Suita, Osaka 565-0871 (Japan); Inogamov, Nail [Landau Institute for Theoretical Physics, Russian Academy of Sciences, 1-A, Akademika Semenova av., Chernogolovka, Moscow Region 142432 (Russian Federation)

    2014-11-14

    We investigated the optical emission from the ablating surfaces induced by the irradiations of soft x-ray laser (SXRL) pulses with the aim of estimation of the maximum electron temperature. No emission signal in the spectral range of 400–800 nm could be observed despite the formation of damage structures on the target surfaces. Hence, we estimated an upper limit for the electron temperature of 0.4–0.7 eV for the process duration of 100–1000 ps. Our results imply that the ablation and/or surface modification by the SXRL is not accompanied by plasma formation but is induced by thermo-mechanical pressure, which is so called a spallative ablation. This spallative ablation process occurs in the low electron temperature region of a non-equilibrium state of warm dense matter.

  5. Kissing G domains of MnmE monitored by X-ray crystallography and pulse electron paramagnetic resonance spectroscopy.

    Science.gov (United States)

    Meyer, Simon; Böhme, Sabine; Krüger, André; Steinhoff, Heinz-Jürgen; Klare, Johann P; Wittinghofer, Alfred

    2009-10-01

    MnmE, which is involved in the modification of the wobble position of certain tRNAs, belongs to the expanding class of G proteins activated by nucleotide-dependent dimerization (GADs). Previous models suggested the protein to be a multidomain protein whose G domains contact each other in a nucleotide dependent manner. Here we employ a combined approach of X-ray crystallography and pulse electron paramagnetic resonance (EPR) spectroscopy to show that large domain movements are coupled to the G protein cycle of MnmE. The X-ray structures show MnmE to be a constitutive homodimer where the highly mobile G domains face each other in various orientations but are not in close contact as suggested by the GDP-AlF(x) structure of the isolated domains. Distance measurements by pulse double electron-electron resonance (DEER) spectroscopy show that the G domains adopt an open conformation in the nucleotide free/GDP-bound and an open/closed two-state equilibrium in the GTP-bound state, with maximal distance variations of 18 A. With GDP and AlF(x), which mimic the transition state of the phosphoryl transfer reaction, only the closed conformation is observed. Dimerization of the active sites with GDP-AlF(x) requires the presence of specific monovalent cations, thus reflecting the requirements for the GTPase reaction of MnmE. Our results directly demonstrate the nature of the conformational changes MnmE was previously suggested to undergo during its GTPase cycle. They show the nucleotide-dependent dynamic movements of the G domains around two swivel positions relative to the rest of the protein, and they are of crucial importance for understanding the mechanistic principles of this GAD.

  6. Kissing G domains of MnmE monitored by X-ray crystallography and pulse electron paramagnetic resonance spectroscopy.

    Directory of Open Access Journals (Sweden)

    Simon Meyer

    2009-10-01

    Full Text Available MnmE, which is involved in the modification of the wobble position of certain tRNAs, belongs to the expanding class of G proteins activated by nucleotide-dependent dimerization (GADs. Previous models suggested the protein to be a multidomain protein whose G domains contact each other in a nucleotide dependent manner. Here we employ a combined approach of X-ray crystallography and pulse electron paramagnetic resonance (EPR spectroscopy to show that large domain movements are coupled to the G protein cycle of MnmE. The X-ray structures show MnmE to be a constitutive homodimer where the highly mobile G domains face each other in various orientations but are not in close contact as suggested by the GDP-AlF(x structure of the isolated domains. Distance measurements by pulse double electron-electron resonance (DEER spectroscopy show that the G domains adopt an open conformation in the nucleotide free/GDP-bound and an open/closed two-state equilibrium in the GTP-bound state, with maximal distance variations of 18 A. With GDP and AlF(x, which mimic the transition state of the phosphoryl transfer reaction, only the closed conformation is observed. Dimerization of the active sites with GDP-AlF(x requires the presence of specific monovalent cations, thus reflecting the requirements for the GTPase reaction of MnmE. Our results directly demonstrate the nature of the conformational changes MnmE was previously suggested to undergo during its GTPase cycle. They show the nucleotide-dependent dynamic movements of the G domains around two swivel positions relative to the rest of the protein, and they are of crucial importance for understanding the mechanistic principles of this GAD.

  7. X-ray generation by inverse Compton scattering at the superconducting RF test facility

    Energy Technology Data Exchange (ETDEWEB)

    Shimizu, Hirotaka, E-mail: hirotaka@post.kek.jp [KEK, 1-1 Oho, Tsukuba 305-0801, Ibaraki (Japan); Akemoto, Mitsuo; Arai, Yasuo; Araki, Sakae; Aryshev, Alexander; Fukuda, Masafumi; Fukuda, Shigeki; Haba, Junji; Hara, Kazufumi; Hayano, Hitoshi; Higashi, Yasuo; Honda, Yosuke; Honma, Teruya; Kako, Eiji; Kojima, Yuji; Kondo, Yoshinari; Lekomtsev, Konstantin; Matsumoto, Toshihiro; Michizono, Shinichiro; Miyoshi, Toshinobu [KEK, 1-1 Oho, Tsukuba 305-0801, Ibaraki (Japan); and others

    2015-02-01

    Quasi-monochromatic X-rays with high brightness have a broad range of applications in fields such as life sciences, bio-, medical applications, and microlithography. One method for generating such X-rays is via inverse Compton scattering (ICS). X-ray generation experiments using ICS were carried out at the superconducting RF test facility (STF) accelerator at KEK. A new beam line, newly developed four-mirror optical cavity system, and new X-ray detector system were prepared for experiments downstream section of the STF electron accelerator. Amplified pulsed photons were accumulated into a four-mirror optical cavity and collided with an incoming 40 MeV electron beam. The generated X-rays were detected using a microchannel plate (MCP) detector for X-ray yield measurements and a new silicon-on-insulator (SOI) detector system for energy measurements. The detected X-ray yield by the MCP detector was 1756.8±272.2 photons/(244 electron bunches). To extrapolate this result to 1 ms train length under 5 Hz operations, 4.60×10{sup 5} photons/1%-bandwidth were obtained. The peak X-ray energy, which was confirmed by the SOI detector, was 29 keV, and this is consistent with ICS X-rays.

  8. 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).

  9. 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.

  10. Broadband multilayer soft X-ray mirrors for attosecond pulse formation at photon energies above 100 eV

    Energy Technology Data Exchange (ETDEWEB)

    Hofstetter, Michael; Schuster, Joerg; Kleineberg, Ulf [LMU, Physik (Germany); Aquila, Andrew [CXRO (United States); Schulze, Martin; Fiess, Markus; Gouliemakis, Eleftherios; Krausz, Ferenc [MPQ (Germany); Huth, Martin [LMU, Chemie (Germany)

    2009-07-01

    We report on the development, fabrication and application of multilayer mirrors as broadband soft-X-ray optical components for the formation of attosecond (1 asec=10{sup -18}s)pulses from high harmonic radiation. Until recently, attosecond physics was merely confined to the photon energy range below 100 eV due to the properties of Mo/Si multilayer and single isolated pulses of 80 asec pulse duration have been achieved. For many applications, e.g. in the characterization of the photoemission dynamics from solid surfaces or the characterization of ultrafast surface plasmon dynamics in metallic nanostructures by attosecond pump-probe spectroscopy, higher photon energies are desirable to address deeper bound electronic core states or to increase the kinetic energy of the emitted photoelectrons. Here, we introduce new aperiodic broad bandwidth multilayer systems based on lanthanum (e.g. LaMo, LaB{sub 4}CMo, LaB{sub 4}C, MoB{sub 4}C),for the 100-190 eV photon energy range. Multilayer properties like interface roughness, interlayer formation and reflectivity are discussed. Finally, first applications for spectral filtering of the HHG comb above 100 eV are presented.

  11. Flexible control of femtosecond pulse duration and separation using an emittance-spoiling foil in x-ray free-electron lasers

    Energy Technology Data Exchange (ETDEWEB)

    Ding, Y. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Behrens, C. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Coffee, R. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Decker, F. -J. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Emma, P. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Field, C. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Helml, W. [Technische Univ. Munchen, Garching (Germany); Huang, Z. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Krejcik, P. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Krzywinski, J. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Loos, H. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Lutman, A. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Marinelli, A. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Maxwell, T. J. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Turner, J. [SLAC National Accelerator Lab., Menlo Park, CA (United States)

    2015-06-22

    We report experimental studies of generating and controlling femtosecond x-ray pulses in free-electron lasers (FELs) using an emittance spoiling foil. By selectivity spoiling the transverse emittance of the electron beam, the output pulse duration or double-pulse separation is adjusted with a variable size single or double slotted foil. Measurements were performed with an X-band transverse deflector located downstream of the FEL undulator, from which both the FEL lasing and emittance spoiling effects are observed directly.

  12. Optimizing pulse-pileup detection for soft-x-ray spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Greenberger, A.J.

    1981-04-01

    The problem of optimizing detection of the pileup of randomly occurring exponential tail pulses in white noise is considered. An attempt is made to reduce the process to an algorithm that could practically be performed in real time. Quantitative estimates are made for the performance of such an optimum detector. The relation to a more general pattern recognition problem is mentioned.

  13. Possibility of Ion Beam Pulse Compression by X-Ray Conversion

    Science.gov (United States)

    Yabe, Takashi

    1985-02-01

    A previously proposed scheme for ion beam pulse compression is reexamined from a different viewpoint. It is shown that the criticisms made by Unterseer and Meyer-ter-Vehn are not reasonable in a real target configuration. In addition, the spherically converging effect is shown to offer further advantages.

  14. High Brightness OLED Lighting

    Energy Technology Data Exchange (ETDEWEB)

    Spindler, Jeffrey [OLEDWorks LLC; Kondakova, Marina [OLEDWorks LLC; Boroson, Michael [OLEDWorks LLC; Hamer, John [OLEDWorks LLC

    2016-05-25

    In this work we describe the technology developments behind our current and future generations of high brightness OLED lighting panels. We have developed white and amber OLEDs with excellent performance based on the stacking approach. Current products achieve 40-60 lm/W, while future developments focus on achieving 80 lm/W or higher.

  15. Pair annihilation in laser pulses: Optical versus x-ray free-electron laser regimes

    OpenAIRE

    Ilderton, Anton; Johansson, Petter; Marklund, Mattias

    2011-01-01

    We discuss the theory and phenomenology of pair annihilation, within an ultra-short laser pulse, to a single photon. The signature of this process is the uni-directional emission of single photons with a fixed energy. We show that the cross section is significantly larger than for two-photon pair annihilation in vacuum, with XFEL parameters admitting a much clearer signal than optical beams.

  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. Characterization of continuous and pulsed emission modes of a hybrid micro focus x-ray source for medical imaging applications

    Science.gov (United States)

    Ghani, Muhammad U.; Wong, Molly D.; Ren, Liqiang; Wu, Di; Zheng, Bin; Rong, John. X.; Wu, Xizeng; Liu, Hong

    2017-05-01

    The aim of this study was to quantitatively characterize a micro focus x-ray tube that can operate in both continuous and pulsed emission modes. The micro focus x-ray source (Model L9181-06, Hamamatsu Photonics, Japan) has a varying focal spot size ranging from 16 μm to 50 μm as the source output power changes from 10 to 39 W. We measured the source output, beam quality, focal spot sizes, kV accuracy, spectra shapes and spatial resolution. Source output was measured using an ionization chamber for various tube voltages (kVs) with varying current (μA) and distances. The beam quality was measured in terms of half value layer (HVL), kV accuracy was measured with a non-invasive kV meter, and the spectra was measured using a compact integrated spectrometer system. The focal spot sizes were measured using a slit method with a CCD detector with a pixel pitch of 22 μm. The spatial resolution was quantitatively measured using the slit method with a CMOS flat panel detector with a 50 μm pixel pitch, and compared to the qualitative results obtained by imaging a contrast bar pattern. The focal spot sizes in the vertical direction were smaller than that of the horizontal direction, the impact of which was visible when comparing the spatial resolution values. Our analyses revealed that both emission modes yield comparable imaging performances in terms of beam quality, spectra shape and spatial resolution effects. There were no significantly large differences, thus providing the motivation for future studies to design and develop stable and robust cone beam imaging systems for various diagnostic applications.

  18. A comparative study of the ionic keV X-ray line emission from plasma produced by the femtosecond, picosecond and nanosecond duration laser pulses

    Indian Academy of Sciences (India)

    V Arora; P A Naik; B S Rao; P D Gupta

    2012-02-01

    We report here an experimental study of the ionic keV X-ray line emission from magnesium plasma produced by laser pulses of three widely different pulse durations (FWHM) of 45 fs, 25 ps and 3 ns, at a constant laser fluence of ∼ 1.5 × 104 J cm-2. It is observed that the X-ray yield of the resonance lines from the higher ionization states such as H- and He-like ions decreases on decreasing the laser pulse duration, even though the peak laser intensities of 3.5 × 1017 W cm-2 for the 45 fs pulses and 6.2 × 1014 W cm-2 for the 25 ps pulses are much higher than 5 × 1012 W cm-2 for the 3 ns laser pulse. The results were explained in terms of the ionization equilibrium time for different ionization states in the heated plasma. The study can be useful to make optimum choice of the laser pulse duration to produce short pulse intense X-ray line emission from the plasma and to get the knowledge of the degree of ionization in the plasma.

  19. Pulsed X-rays for interventional radiology: tests on active personal dosemeters (APD) (European project FP7 ORAMED WP3); Rayons X pulses pour la radiologie interventionnelle: tests sur dosimetres personnel actifs

    Energy Technology Data Exchange (ETDEWEB)

    Denoziere, M.; Bordy, J.M.; Daures, J.; Lecerf, N

    2009-07-01

    this report presents the results of the tests performed on Active Personal dosemeters (A.P.D.) to check their responses in pulsed X-ray beam used in interventional X-ray radiology. this work is one of the goal of O.R.A.M.E.D W.P.3. (Optimization of radiation protection for medical staff)The response of seven A.P.D.s types was measured in terms of dose equivalent Hp (10) for different pulsed X-ray width and dose rate. (author)

  20. Coherent-pulse 2D crystallography using a free-electron laser x-ray source.

    Science.gov (United States)

    Mancuso, A P; Schropp, A; Reime, B; Stadler, L-M; Singer, A; Gulden, J; Streit-Nierobisch, S; Gutt, C; Grübel, G; Feldhaus, J; Staier, F; Barth, R; Rosenhahn, A; Grunze, M; Nisius, T; Wilhein, T; Stickler, D; Stillrich, H; Frömter, R; Oepen, H-P; Martins, M; Pfau, B; Günther, C M; Könnecke, R; Eisebitt, S; Faatz, B; Guerassimova, N; Honkavaara, K; Kocharyan, V; Treusch, R; Saldin, E; Schreiber, S; Schneidmiller, E A; Yurkov, M V; Weckert, E; Vartanyants, I A

    2009-01-23

    Coherent diffractive imaging for the reconstruction of a two-dimensional (2D) finite crystal structure with a single pulse train of free-electron laser radiation at 7.97 nm wavelength is demonstrated. This measurement shows an advance on traditional coherent imaging techniques by applying it to a periodic structure. It is also significant that this approach paves the way for the imaging of the class of specimens which readily form 2D, but not three-dimensional crystals. We show that the structure is reconstructed to the detected resolution, given an adequate signal-to-noise ratio.

  1. Investigation of dynamics of soft X-ray radiation of mixed-material wire-arrays on S-300 pulsed power generator

    NARCIS (Netherlands)

    Cai, HC; Chernenko, AC; Korolev, VD; Ustroev, GI; Ivanov, MI

    2004-01-01

    The dynamics of radiation spectra of fast Z-pinch plasmas was studied. The experiments were carried out on the S-300 pulsed power machine (4 MA, 0.15 Omega, 100 ns). By means of the polychromator, X-ray spectra of imploding wire arrays were measured in the range of 60 divided by 1500 eV, where the

  2. Generating Isolated Terawatt-Attosecond X-ray Pulses via a Chirped Laser Enhanced High-Gain Free-electron Laser

    CERN Document Server

    Wang, Zhen; Zhao, Zhentang

    2016-01-01

    A feasible method is proposed to generate isolated attosecond terawatt x-ray radiation pulses in high-gain free-electron lasers. In the proposed scheme, a frequency chirped laser pulse is employed to generate a gradually-varied spacing current enhancement of the electron beam and a series of spatiotemporal shifters are applied between the undulator sections to amplify a chosen ultra-short radiation pulse from self-amplified spontaneous emission. Three-dimensional start-to-end simulations have been carried out and the calculation results demonstrated that 0.15 nm x-ray pulses with peak power over 1TW and duration of several tens of attoseconds could be achieved by using the proposed technique.

  3. Generating isolated terawatt-attosecond x-ray pulses via a chirped-laser-enhanced high-gain free-electron laser

    Directory of Open Access Journals (Sweden)

    Zhen Wang

    2017-04-01

    Full Text Available A feasible method is proposed to generate isolated attosecond terawatt x-ray radiation pulses in high-gain free-electron lasers. In the proposed scheme, a frequency chirped laser pulse is employed to generate a gradually varied spacing current enhancement of the electron beam, and a series of spatiotemporal shifters are applied between the undulator sections to amplify a chosen ultrashort radiation pulse from self-amplified spontaneous emission. Three-dimensional start-to-end simulations have been carried out, and the calculation results demonstrated that 0.15 nm x-ray pulses with a peak power over 1 TW and a duration of several tens of attoseconds could be achieved by using the proposed technique.

  4. Single and double core-hole ion emission spectroscopy of transient neon plasmas produced by ultraintense x-ray laser pulses

    Science.gov (United States)

    Gao, Cheng; Zeng, Jiaolong; Yuan, Jianmin

    2016-05-01

    Single core-hole (SCH) and double core-hole (DCH) spectroscopy is investigated systematically for neon gas in the interaction with ultraintense x-ray pulses with photon energy from 937 eV to 2000 eV. A time-dependent rate equation, implemented in the detailed level accounting approximation, is utilized to study the dynamical evolution of the level population and emission properties of the laser-produced highly transient plasmas. The plasma density effects on level populations are demonstrated with an x-ray photon energy of 2000 eV. For laser photon energy in the range of 937 - 1360 eV, resonant absorptions (RA) of 1s-np (n> = 2) transitions play important roles in time evolution of the population and DCH emission spectroscopy. For x-ray photon energy larger than 1360 eV, no RA exist and transient plasmas show different features in the DCH spectroscopy.

  5. Pulse-front tilt caused by the use of a grating monochromator and self-seeding of soft X-ray FELs

    CERN Document Server

    Geloni, Gianluca; Saldin, Evgeni

    2012-01-01

    Self-seeding is a promising approach to significantly narrow the SASE bandwidth of XFELs to produce nearly transform-limited pulses. The development of such schemes in the soft X-ray wavelength range necessarily involves gratings as dispersive elements. These introduce, in general, a pulse-front tilt, which is directly proportional to the angular dispersion. Pulse-front tilt may easily lead to a seed signal decrease by a factor two or more. Suggestions on how to minimize the pulse-front tilt effect in the self-seeding setup are given.

  6. X-ray laser–induced electron dynamics observed by femtosecond diffraction from nanocrystals of Buckminsterfullerene

    Science.gov (United States)

    Abbey, Brian; Dilanian, Ruben A.; Darmanin, Connie; Ryan, Rebecca A.; Putkunz, Corey T.; Martin, Andrew V.; Wood, David; Streltsov, Victor; Jones, Michael W. M.; Gaffney, Naylyn; Hofmann, Felix; Williams, Garth J.; Boutet, Sébastien; Messerschmidt, Marc; Seibert, M. Marvin; Williams, Sophie; Curwood, Evan; Balaur, Eugeniu; Peele, Andrew G.; Nugent, Keith A.; Quiney, Harry M.

    2016-01-01

    X-ray free-electron lasers (XFELs) deliver x-ray pulses with a coherent flux that is approximately eight orders of magnitude greater than that available from a modern third-generation synchrotron source. The power density of an XFEL pulse may be so high that it can modify the electronic properties of a sample on a femtosecond time scale. Exploration of the interaction of intense coherent x-ray pulses and matter is both of intrinsic scientific interest and of critical importance to the interpretation of experiments that probe the structures of materials using high-brightness femtosecond XFEL pulses. We report observations of the diffraction of extremely intense 32-fs nanofocused x-ray pulses by a powder sample of crystalline C60. We find that the diffraction pattern at the highest available incident power significantly differs from the one obtained using either third-generation synchrotron sources or XFEL sources operating at low output power and does not correspond to the diffraction pattern expected from any known phase of crystalline C60. We interpret these data as evidence of a long-range, coherent dynamic electronic distortion that is driven by the interaction of the periodic array of C60 molecular targets with intense x-ray pulses of femtosecond duration. PMID:27626076

  7. X-ray laser-induced electron dynamics observed by femtosecond diffraction from nanocrystals of Buckminsterfullerene.

    Science.gov (United States)

    Abbey, Brian; Dilanian, Ruben A; Darmanin, Connie; Ryan, Rebecca A; Putkunz, Corey T; Martin, Andrew V; Wood, David; Streltsov, Victor; Jones, Michael W M; Gaffney, Naylyn; Hofmann, Felix; Williams, Garth J; Boutet, Sébastien; Messerschmidt, Marc; Seibert, M Marvin; Williams, Sophie; Curwood, Evan; Balaur, Eugeniu; Peele, Andrew G; Nugent, Keith A; Quiney, Harry M

    2016-09-01

    X-ray free-electron lasers (XFELs) deliver x-ray pulses with a coherent flux that is approximately eight orders of magnitude greater than that available from a modern third-generation synchrotron source. The power density of an XFEL pulse may be so high that it can modify the electronic properties of a sample on a femtosecond time scale. Exploration of the interaction of intense coherent x-ray pulses and matter is both of intrinsic scientific interest and of critical importance to the interpretation of experiments that probe the structures of materials using high-brightness femtosecond XFEL pulses. We report observations of the diffraction of extremely intense 32-fs nanofocused x-ray pulses by a powder sample of crystalline C60. We find that the diffraction pattern at the highest available incident power significantly differs from the one obtained using either third-generation synchrotron sources or XFEL sources operating at low output power and does not correspond to the diffraction pattern expected from any known phase of crystalline C60. We interpret these data as evidence of a long-range, coherent dynamic electronic distortion that is driven by the interaction of the periodic array of C60 molecular targets with intense x-ray pulses of femtosecond duration.

  8. A low-power CMOS ASIC for X-ray Silicon Drift Detectors low-noise pulse processing

    Science.gov (United States)

    Ahangarianabhari, M.; Bertuccio, G.; Macera, D.; Malcovati, P.; Grassi, M.; Rashevsky, A.; Rashevskaya, I.; Vacchi, A.; Zampa, G.; Zampa, N.; Fuschino, F.; Evangelista, Y.; Campana, R.; Labanti, C.; Feroci, M.

    2014-03-01

    We present an Application Specific Integrated Circuit (ASIC), named VEGA-1, designed and manufactured for low-power analog pulse processing of signals from Silicon Drift Detectors (SDDs). The VEGA-1 ASIC consists of an analog and a digital/mixed-signal section to achieve all the functionalities and specifications required for high-resolution X-ray spectroscopy in the energy range from 500 eV to 60 keV with low power consumption. The VEGA-1 ASIC has been designed and manufactured in 0.35-μm CMOS mixed-signal technology in single and 32-channel version with dimensions of 200 μm × 500 μm per channel. A minimum intrinsic ENC of 12 electrons r.m.s. at 3.6 μs shaping time and room temperature is measured for the ASIC without detector. The VEGA-1 has been tested with Q10-SDD designed in Trieste and fabricated at FBK, with an active area of 10 mm2 and a thickness of 450 μm. The aforementioned detector has an anode current of about 180 pA at +22°C. A minimum Equivalent Noise Charge (ENC) of 16 electrons r.m.s. at 3.0 μs shaping time and -30°C has been demonstrated with a total measured power consumption of 482 μW.

  9. Analysis of 3D Prints by X-ray Computed Microtomography and Terahertz Pulsed Imaging.

    Science.gov (United States)

    Markl, Daniel; Zeitler, J Axel; Rasch, Cecilie; Michaelsen, Maria Høtoft; Müllertz, Anette; Rantanen, Jukka; Rades, Thomas; Bøtker, Johan

    2017-05-01

    A 3D printer was used to realise compartmental dosage forms containing multiple active pharmaceutical ingredient (API) formulations. This work demonstrates the microstructural characterisation of 3D printed solid dosage forms using X-ray computed microtomography (XμCT) and terahertz pulsed imaging (TPI). Printing was performed with either polyvinyl alcohol (PVA) or polylactic acid (PLA). The structures were examined by XμCT and TPI. Liquid self-nanoemulsifying drug delivery system (SNEDDS) formulations containing saquinavir and halofantrine were incorporated into the 3D printed compartmentalised structures and in vitro drug release determined. A clear difference in terms of pore structure between PVA and PLA prints was observed by extracting the porosity (5.5% for PVA and 0.2% for PLA prints), pore length and pore volume from the XμCT data. The print resolution and accuracy was characterised by XμCT and TPI on the basis of the computer-aided design (CAD) models of the dosage form (compartmentalised PVA structures were 7.5 ± 0.75% larger than designed; n = 3). The 3D printer can reproduce specific structures very accurately, whereas the 3D prints can deviate from the designed model. The microstructural information extracted by XμCT and TPI will assist to gain a better understanding about the performance of 3D printed dosage forms.

  10. Visualizing the non-equilibrium dynamics of photoinduced intramolecular electron transfer with femtosecond X-ray pulses

    DEFF Research Database (Denmark)

    Canton, Sophie E.; Kjær, Kasper S.; Vankó, György;

    2015-01-01

    spectroscopy with ultrafast X-ray emission spectroscopy and diffuse X-ray scattering at the SACLA facility to track the non-equilibrated electronic and structural dynamics within a bimetallic donor–acceptor complex that contains an optically dark centre. Exploiting the 100-fold increase in temporal resolution...... states is a key mechanistic feature. The present study demonstrates the extensive potential of femtosecond X-ray techniques as diagnostics of non-adiabatic electron transfer processes in synthetic and biological systems, and some directions for future studies, are outlined....

  11. 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 ...

  12. 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 ...

  13. High resolution energy-angle correlation measurement of hard x rays from laser-Thomson backscattering.

    Science.gov (United States)

    Jochmann, A; Irman, A; Bussmann, M; Couperus, J P; Cowan, T E; Debus, A D; Kuntzsch, M; Ledingham, K W D; Lehnert, U; Sauerbrey, R; Schlenvoigt, H P; Seipt, D; Stöhlker, Th; Thorn, D B; Trotsenko, S; Wagner, A; Schramm, U

    2013-09-13

    Thomson backscattering of intense laser pulses from relativistic electrons not only allows for the generation of bright x-ray pulses but also for the investigation of the complex particle dynamics at the interaction point. For this purpose a complete spectral characterization of a Thomson source powered by a compact linear electron accelerator is performed with unprecedented angular and energy resolution. A rigorous statistical analysis comparing experimental data to 3D simulations enables, e.g., the extraction of the angular distribution of electrons with 1.5% accuracy and, in total, provides predictive capability for the future high brightness hard x-ray source PHOENIX (photon electron collider for narrow bandwidth intense x rays) and potential gamma-ray sources.

  14. Improvement of density resolution in short-pulse hard x-ray radiographic imaging using detector stacks

    Science.gov (United States)

    Borm, B.; Gärtner, F.; Khaghani, D.; Neumayer, P.

    2016-09-01

    We demonstrate that stacking several imaging plates (IPs) constitutes an easy method to increase hard x-ray detection efficiency. Used to record x-ray radiographic images produced by an intense-laser driven hard x-ray backlighter source, the IP stacks resulted in a significant improvement of the radiograph density resolution. We attribute this to the higher quantum efficiency of the combined detectors, leading to a reduced photon noise. Electron-photon transport simulations of the interaction processes in the detector reproduce the observed contrast improvement. Increasing the detection efficiency to enhance radiographic imaging capabilities is equally effective as increasing the x-ray source yield, e.g., by a larger drive laser energy.

  15. Improvement of density resolution in short-pulse hard x-ray radiographic imaging using detector stacks

    Energy Technology Data Exchange (ETDEWEB)

    Borm, B.; Gärtner, F.; Khaghani, D. [GSI Helmholtzzentrum für Schwerionenforschung, Darmstadt (Germany); Johann Wolfgang Goethe-Universität, Frankfurt am Main (Germany); Neumayer, P. [GSI Helmholtzzentrum für Schwerionenforschung, Darmstadt (Germany)

    2016-09-15

    We demonstrate that stacking several imaging plates (IPs) constitutes an easy method to increase hard x-ray detection efficiency. Used to record x-ray radiographic images produced by an intense-laser driven hard x-ray backlighter source, the IP stacks resulted in a significant improvement of the radiograph density resolution. We attribute this to the higher quantum efficiency of the combined detectors, leading to a reduced photon noise. Electron-photon transport simulations of the interaction processes in the detector reproduce the observed contrast improvement. Increasing the detection efficiency to enhance radiographic imaging capabilities is equally effective as increasing the x-ray source yield, e.g., by a larger drive laser energy.

  16. Performance verification and system integration tests of the pulse shape processor for the soft x-ray spectrometer onboard ASTRO-H

    Science.gov (United States)

    Takeda, Sawako; Tashiro, Makoto S.; Ishisaki, Yoshitaka; Tsujimoto, Masahiro; Seta, Hiromi; Shimoda, Yuya; Yamaguchi, Sunao; Uehara, Sho; Terada, Yukikatsu; Fujimoto, Ryuichi; Mitsuda, Kazuhisa

    2014-07-01

    The soft X-ray spectrometer (SXS) aboard ASTRO-H is equipped with dedicated digital signal processing units called pulse shape processors (PSPs). The X-ray microcalorimeter system SXS has 36 sensor pixels, which are operated at 50 mK to measure heat input of X-ray photons and realize an energy resolution of 7 eV FWHM in the range 0.3-12.0 keV. Front-end signal processing electronics are used to filter and amplify the electrical pulse output from the sensor and for analog-to-digital conversion. The digitized pulses from the 36 pixels are multiplexed and are sent to the PSP over low-voltage differential signaling lines. Each of two identical PSP units consists of an FPGA board, which assists the hardware logic, and two CPU boards, which assist the onboard software. The FPGA board triggers at every pixel event and stores the triggering information as a pulse waveform in the installed memory. The CPU boards read the event data to evaluate pulse heights by an optimal filtering algorithm. The evaluated X-ray photon data (including the pixel ID, energy, and arrival time information) are transferred to the satellite data recorder along with event quality information. The PSP units have been developed and tested with the engineering model (EM) and the flight model. Utilizing the EM PSP, we successfully verified the entire hardware system and the basic software design of the PSPs, including their communication capability and signal processing performance. In this paper, we show the key metrics of the EM test, such as accuracy and synchronicity of sampling clocks, event grading capability, and resultant energy resolution.

  17. Characterization of pulsed x-ray beams for tests of electronic dosemeter performance; Caracterizacao de feixes de raios X pulsados para testes de desempenho de dosimetros eletronicos

    Energy Technology Data Exchange (ETDEWEB)

    Guimaraes, Margarete C.; Silva, Teogenes A. da, E-mail: mcg@cdtn.br, E-mail: silvata@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil). Curso de Pos-Graduacao em Ciencias e Tecnologia das Radiacoes, Materiais e Minerais

    2013-10-01

    Electronic dosimeters, due to direct reading, have been increasingly used for individual or area monitoring for purposes of radiation protection in X-ray fields used in diagnostic radiology. Deficiencies of performance in pulsed beams of such dosimeters have been published, which are not detected by the calibration procedures and performance tests established by international standards only for continuous beams of radiation. In Brazil, there are no performance requirements of dosimeters in pulsed beams, or a laboratory that performs testing for reliability in the use of dosimeters. This study aims to characterize the X-ray machine Medical VMI 800 Plus in the Laboratory Calibration of Dosimeters of CDTN/CNEN - Brazilian CNEN institute - and study the feasibility of its use for performance testing of electronic dosimeters. (author)

  18. LIGHT SOURCE: TW Laser system for Thomson scattering X-ray light source at Tsinghua University

    Science.gov (United States)

    Yan, Li-Xm; Du, Ying-Chao; Du, Qiang; Li, Ren-Kai; Hua, Jian-Fei; Huang, Wen-Hui; Tang, Chuan-Xiang

    2009-06-01

    A TW (Tera Watt) laser system based on Ti:sapphire mainly for the Tsinghua Thomson scattering X-ray light source (TTX) is being built. Both UV (ultraviolet) laser pulse for driving the photocathode radio-frequency (RF) gun and the IR (infrared) laser pulse as the electron-beam-scattered-light are provided by the system. Efforts have also been made in laser pulse shaping and laser beam transport to optimize the high-brightness electron beam production by the photocathode RF gun.

  19. TW Laser system for Thomson scattering X-ray light source at Tsinghua University

    Institute of Scientific and Technical Information of China (English)

    YAN Li-Xin; DU Ying-Chao; DU Qiang; LI Ren-Kai; HUA Jian-Fei; HUANG Wen-Hui; TANG Chuan-Xiang

    2009-01-01

    A TW(Tera Watt)laser system based on Ti:sapphire mainly for the Tsinghua Thomson scattering X-ray light source(TTX)is being built.Both UV(ultraviolet)laser pulse for driving the photocathode radiofrequency(RF)gun and the IR(infrared)laser pulse as the electron-beam-scattered-light are provided by the system.Efforts have also been made in laser pulse shaping and laser beam transport to optimize the high-brightness electron beam production by the photocathode RF gun.

  20. In-situ small-angle x-ray scattering study of nanoparticles in the plasma plume induced by pulsed laser irradiation of metallic targets

    Energy Technology Data Exchange (ETDEWEB)

    Lavisse, L.; Jouvard, J.-M.; Girault, M.; Potin, V.; Andrzejewski, H.; Marco de Lucas, M. C.; Bourgeois, S. [Laboratoire Interdisciplinaire Carnot de Bourgogne (ICB), UMR 6303 CNRS-Universite de Bourgogne, 9 Avenue A. Savary, BP 47870-21078 Dijon Cedex (France); Le Garrec, J.-L.; Carles, S.; Mitchell, J. B. A. [Institut de Physique de Rennes, UMR 6251 CNRS-Universite de Rennes 1, 35042 Rennes Cedex (France); Hallo, L. [CEA CESTA, 15 Avenue des Sablieres CS 60001, 33116 Le Barp Cedex (France); Perez, J. [Synchrotron SOLEIL, L' Orme des Merisiers, Saint-Aubin, F-91192 Gif-sur-Yvette Cedex (France); Decloux, J. [Kaluti System, Optique et Laser, Centre Scientifique d' Orsay, 91400 Orsay (France)

    2012-04-16

    Small angle x-ray scattering was used to probe in-situ the formation of nanoparticles in the plasma plume generated by pulsed laser irradiation of a titanium metal surface under atmospheric conditions. The size and morphology of the nanoparticles were characterized as function of laser irradiance. Two families of nanoparticles were identified with sizes on the order of 10 and 70 nm, respectively. These results were confirmed by ex-situ transmission electron microscopy experiments.

  1. 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.

  2. 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.

  3. Discovery of luminous pulsed hard X-ray emission from anomalous X-ray pulsars 1RXS J1708-4009, 4U 0142+61 and 1E 2259+586 by INTEGRAL and RXTE

    CERN Document Server

    Kuiper, L; Den Hartog, P R; Hermsen, W

    2006-01-01

    We report on the discovery of hard spectral tails for energies above 10 keV in the total and pulsed spectra of anomalous X-ray pulsars 1RXS J1708-4009, 4U 0142+61 and 1E 2259+586 using RXTE PCA (2-60 keV) and HEXTE (15-250 keV) data and INTEGRAL IBIS ISGRI (20-300 keV) data. Improved spectral information on 1E 1841-045 is presented. The pulsed and total spectra measured above 10 keV have power-law shapes and there is so far no significant evidence for spectral breaks or bends up to ~150 keV. The pulsed spectra are exceptionally hard with indices measured for 4 AXPs approximately in the range -1.0 -- 1.0. We also reanalyzed archival CGRO COMPTEL (0.75-30 MeV) data to search for signatures from our set of AXPs. No detections can be claimed, but the obtained upper-limits in the MeV band indicate that for 1RXS J1708-4009, 4U 0142+61 and 1E 1841-045 strong breaks must occur somewhere between 150 and 750 keV.

  4. Visualizing the non-equilibrium dynamics of photoinduced intramolecular electron transfer with femtosecond X-ray pulses

    DEFF Research Database (Denmark)

    Canton, Sophie E.; Kjær, Kasper S.; Vankó, György;

    2015-01-01

    Ultrafast photoinduced electron transfer preceding energy equilibration still poses many experimental and conceptual challenges to the optimization of photoconversion since an atomic-scale description has so far been beyond reach. Here we combine femtosecond transient optical absorption...... spectroscopy with ultrafast X-ray emission spectroscopy and diffuse X-ray scattering at the SACLA facility to track the non-equilibrated electronic and structural dynamics within a bimetallic donor–acceptor complex that contains an optically dark centre. Exploiting the 100-fold increase in temporal resolution...

  5. Fully coherent hard X-ray generation by two-stage of Phase-merging Enhanced Harmonic Generation

    CERN Document Server

    Wang, Guanglei; Yang, Xueming; Feng, Chao; Deng, Haixiao

    2016-01-01

    Cascading stages of seeded free electron laser (FEL) is a promising way to produce fully coherent X-ray radiations. We study a new approach to produce coherent hard X-rays by cascading the recently proposed phase-merging enhanced harmonic generation (PEHG). The scheme consists of one dogleg and two PEHG configurations, which may be one of the leading candidates for the extracted undulator branch in future X-ray FEL facilities. FEL physics studies show that such a scheme is feasible within the present technology and can provide high brightness X-ray radiation pulses with narrow bandwidth and fully coherence, and the radiated peak power at 1 angstrom wavelength converted from an initial 200 nm seed laser is over 2 GW.

  6. Fully coherent hard X-ray generation by two-stage phase-merging enhanced harmonic generation

    Science.gov (United States)

    Wang, Guang-Lei; Zhang, Wei-Qing; Yang, Xue-Ming; Feng, Chao; Deng, Hai-Xiao

    2016-09-01

    Cascading stages of seeded free electron lasers (FELs) is a promising way to produce fully coherent X-ray radiation. We study a new approach to produce coherent hard X-rays by cascading the recently proposed phase-merging enhanced harmonic generation (PEHG) The scheme consists of one dogleg and two PEHG configurations, and may be one of the leading candidates for the extracted undulator branch in future X-ray FEL facilities. FEL physics studies show that such a scheme is feasible within the present technology and can provide high brightness X-ray radiation pulses with narrow bandwidth and full coherence The radiated peak power at 1 Å wavelength converted from an initial 200 nm seed laser is over 2 GW Supported by the National Natural Science Foundation of China (21127902 & 11322550) and Ten Thousand Talent Program

  7. Multiphoton L-shell ionization of H2S using intense x-ray pulses from a free-electron laser

    Science.gov (United States)

    Murphy, B. F.; Fang, L.; Chen, M.-H.; Bozek, J. D.; Kukk, E.; Kanter, E. P.; Messerschmidt, M.; Osipov, T.; Berrah, N.

    2012-11-01

    Sequential multiphoton L-shell ionization of hydrogen sulfide exposed to intense femtosecond pulses of 1.25-keV x rays has been observed via photoelectron, Auger electron, and ion time-of-flight spectroscopies. Monte Carlo simulations based on relativistic Dirac-Hartree-Slater calculations of Auger decay rates in sulfur with single and double L-shell vacancies accurately model the observed spectra. While single-vacancy-only calculations are surprisingly accurate even at the high x-ray intensity used in the experiment, calculations including double-vacancy states improve on yield estimates of highly charged sulfur ions. In the most intense part of the x-ray focal volume, an average molecule absorbs more than five photons, producing multiple L-shell vacancies in 17% of photoionization events according to simulation. For 280-fs pulse duration and ˜1017 W cm-2 focal intensity, the yield of S13+ is ˜1% of the S3+ yield, in good agreement with simulations. An overabundance of S12+, and S14+ observed in the experimental ion spectra is not predicted by either single-vacancy or double-vacancy calculations.

  8. Synchrotron topographic evaluation of strain around craters generated by irradiation with X-ray pulses from free electron laser with different intensities

    Energy Technology Data Exchange (ETDEWEB)

    Wierzchowski, W., E-mail: wojciech.wierzchowski@itme.edu.pl [Institute of Electronic Materials Technology, Wólczyńska 133, Warsaw 01-919 (Poland); Wieteska, K. [National Centre for Nuclear Research, Soltana 7, Otwock-Świerk 05-400 (Poland); Sobierajski, R.; Klinger, D.; Pełka, J.; Żymierska, D. [Polish Academy of Sciences, Institute of Physics, al. Lotników 32/46, Warsaw 02-668 (Poland); Paulmann, C. [DESY HASYLAB, Notkestrasse 85, D-22607 Hamburg (Germany); Hau-Riege, S.P.; London, R.A.; Graf, A. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Burian, T.; Chalupský, J. [Institute of Physics, Academy of Sciences of the Czech Republic, Na Slovance 2, 18221 Prague 8 (Czech Republic); Gaudin, J. [European XFEL GmbH, Albert-Einstein-Ring 19 D-22761 Hamburg (Germany); Krzywinski, J.; Moeller, S.; Messerschmidt, M.; Bozek, J.; Bostedt, Ch. [National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025 (United States)

    2015-12-01

    The silicon sample irradiated with femtosecond soft X-ray pulses at the Linac Coherent Light Source has been studied with several synchrotron X-ray diffraction topographic methods at HASYLAB. The irradiations were performed for two different wavelengths combined with various impact energy controlled by means of the gas attenuator. The topographic investigation revealed characteristic images of the created craters included the inner region reflecting the X-rays at lower angle, coming most probably from part of the silicon melted during the irradiation. The melted region was surrounded by strained outer region, similar to those observed in the case of rod-like inclusion but less regular in view of some irregularity of the beam used for generation of the craters. It was observed that the higher impact energy higher dose of the irradiating pulses resulted in increasing diameter of the melted area of the crater and the range of the strained region around it. Some features of the monochromatic and white beam back reflection section images of the craters were reproduced in numerically simulated images approximating the strain field in the crater by a droplet containing uniformly distributed point inclusions.

  9. Talbot-Lau x-ray deflectometer electron density diagnostic for laser and pulsed power high energy density plasma experiments (invited)

    Science.gov (United States)

    Valdivia, M. P.; Stutman, D.; Stoeckl, C.; Mileham, C.; Begishev, I. A.; Theobald, W.; Bromage, J.; Regan, S. P.; Klein, S. R.; Muñoz-Cordovez, G.; Vescovi, M.; Valenzuela-Villaseca, V.; Veloso, F.

    2016-11-01

    Talbot-Lau X-ray deflectometry (TXD) has been developed as an electron density diagnostic for High Energy Density (HED) plasmas. The technique can deliver x-ray refraction, attenuation, elemental composition, and scatter information from a single Moiré image. An 8 keV Talbot-Lau interferometer was deployed using laser and x-pinch backlighters. Grating survival and electron density mapping were demonstrated for 25-29 J, 8-30 ps laser pulses using copper foil targets. Moiré pattern formation and grating survival were also observed using a copper x-pinch driven at 400 kA, ˜1 kA/ns. These results demonstrate the potential of TXD as an electron density diagnostic for HED plasmas.

  10. Spectral analysis of K-shell X-ray emission of magnesium plasma produced by ultrashort high-intensity laser pulse irradiation

    Indian Academy of Sciences (India)

    V Arora; U Chakravarty; Manoranjan P Singh; J A Chakera; P A Naik; P D Gupta

    2014-02-01

    Spectral analysis of K-shell X-ray emission of magnesium plasma, produced by laser pulses of 45 fs duration, focussed up to an intensity of ∼1018 W cm-2, is carried out. The plasma conditions prevalent during the emission of X-ray spectrum were identified by comparing the experimental spectra with the synthetic spectra generated using the spectroscopic code Prism-SPECT. It is observed that He-like resonance line emission occurs from the plasma region having sub-critical density, whereas K- emission arises from the bulk solid heated to a temperature of 10 eV by the impact of hot electrons. K- line from Be-like ions was used to estimate the hot electron temperature. A power law fit to the electron temperature showed a scaling of 0.47 with laser intensity.

  11. Electron Temperature Measurement Using PIN Diodes as Detectors to Record the X-ray Pulses from a Low-Energy Mather-Type Plasma Focus

    Institute of Scientific and Technical Information of China (English)

    M. Asif; Amna Ikram

    2004-01-01

    In the experiment to determine the plasma electron temperature, a modified multichannel PIN diodes assembly is used as detectors to record the X-ray pulses from a low-energy Mather-type plasma focus device energized by a 32μF, 15 kV (3.6 k J) single capacitor, with deuterium as a filling gas. The ratio of the integrated bremsstrahlung emission transmitting through foils to the total incident flux as a function of foil thickness at various temperatures is obtained for foil absorbers of material. Using 3μm, 6μm, 9μm,12μm,15μm and 18μm thick aluminium absorbers, the transmitted X-ray flux is detected. By comparing the experimental and theoretical curves through a computer program, the plasma electron temperature is determined. Results show that the deuterium focus plasma electron temperature is about 800 eV.

  12. Two mirror X-ray pulse split and delay instrument for femtosecond time resolved investigations at the LCLS free electron laser facility.

    Science.gov (United States)

    Berrah, Nora; Fang, Li; Murphy, Brendan F; Kukk, Edwin; Osipov, Timur Y; Coffee, Ryan; Ferguson, Ken R; Xiong, Hui; Castagna, Jean-Charles; Petrovic, Vlad S; Montero, Sebastian Carron; Bozek, John D

    2016-05-30

    We built a two-mirror based X-ray split and delay (XRSD) device for soft X-rays at the Linac Coherent Light Source free electron laser facility. The instrument is based on an edge-polished mirror design covering an energy range of 250 eV-1800 eV and producing a delay between the two split pulses variable up to 400 femtoseconds with a sub-100 attosecond resolution. We present experimental and simulation results regarding molecular dissociation dynamics in CH3I and CO probed by the XRSD device. We observed ion kinetic energy and branching ratio dependence on the delay times which were reliably produced by the XRSD instrument.

  13. Talbot-Lau x-ray deflectometer electron density diagnostic for laser and pulsed power high energy density plasma experiments (invited)

    Energy Technology Data Exchange (ETDEWEB)

    Valdivia, M. P., E-mail: mpvaldivia@pha.jhu.edu; Stutman, D. [Department of Physics and Astronomy, Johns Hopkins University, Baltimore, Maryland 21218 (United States); Stoeckl, C.; Mileham, C.; Begishev, I. A.; Theobald, W.; Bromage, J.; Regan, S. P. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623 (United States); Klein, S. R. [Center for Laser Experimental Astrophysical Research, University of Michigan, Ann Arbor, Michigan 48105 (United States); Muñoz-Cordovez, G.; Vescovi, M.; Valenzuela-Villaseca, V.; Veloso, F. [Instituto de Física, Pontificia Universidad Católica de Chile, Macul, Santiago (Chile)

    2016-11-15

    Talbot-Lau X-ray deflectometry (TXD) has been developed as an electron density diagnostic for High Energy Density (HED) plasmas. The technique can deliver x-ray refraction, attenuation, elemental composition, and scatter information from a single Moiré image. An 8 keV Talbot-Lau interferometer was deployed using laser and x-pinch backlighters. Grating survival and electron density mapping were demonstrated for 25–29 J, 8–30 ps laser pulses using copper foil targets. Moiré pattern formation and grating survival were also observed using a copper x-pinch driven at 400 kA, ∼1 kA/ns. These results demonstrate the potential of TXD as an electron density diagnostic for HED plasmas.

  14. 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 ...

  15. 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 ...

  16. 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 ...

  17. Femtosecond X-ray magnetic circular dichroism absorption spectroscopy at an X-ray free electron laser

    Energy Technology Data Exchange (ETDEWEB)

    Higley, Daniel J., E-mail: dhigley@stanford.edu; Yuan, Edwin [SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025 (United States); Department of Applied Physics, Stanford University, Stanford, California 94305 (United States); Hirsch, Konstantin; Dakovski, Georgi L.; Jal, Emmanuelle; Lutman, Alberto A.; Coslovich, Giacomo; Hart, Philip; Hoffmann, Matthias C.; Mitra, Ankush; Moeller, Stefan; Ohldag, Hendrik; Seaberg, Matthew; Stöhr, Joachim; Nuhn, Heinz-Dieter; Reid, Alex H.; Dürr, Hermann A.; Schlotter, William F. [SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025 (United States); Liu, Tianmin; MacArthur, James P. [SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025 (United States); Department of Physics, Stanford University, Stanford, California 94305 (United States); and others

    2016-03-15

    X-ray magnetic circular dichroism spectroscopy using an X-ray free electron laser is demonstrated with spectra over the Fe L{sub 3,2}-edges. The high brightness of the X-ray free electron laser combined with high accuracy detection of incident and transmitted X-rays enables ultrafast X-ray magnetic circular dichroism studies of unprecedented sensitivity. This new capability is applied to a study of all-optical magnetic switching dynamics of Fe and Gd magnetic sublattices in a GdFeCo thin film above its magnetization compensation temperature.

  18. Current Problems in X-Ray Emission Spectroscopy

    Science.gov (United States)

    Goldstein, Joseph I.; Williams, David B.; Lyman, Charles E.

    1989-01-01

    Various problems that limit X-ray analysis in the analytical electron microscope are reviewed. Major emphasis is given to the trade-off between minimum mass fraction and spatial resolution. New developments such as high-brightness electron guns, new X-ray spectrometers and clean high-vacuum analysis conditions will lead to major improvements in the accuracy and detectability limits of X-ray emission spectroscopy.

  19. Generation of ultra-large-bandwidth X-ray free-electron-laser pulses with a transverse-gradient undulator.

    Science.gov (United States)

    Prat, Eduard; Calvi, Marco; Reiche, Sven

    2016-07-01

    A new and simple method to generate X-ray free-electron-laser radiation with unprecedented spectral bandwidth above the 10% level is presented. The broad bandwidth is achieved by sending a transversely tilted beam through a transverse-gradient undulator. The extent of the bandwidth can easily be controlled by variation of the beam tilt or the undulator gradient. Numerical simulations confirm the validity and feasibility of this method.

  20. 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.

  1. Variable neutron star free precession in Hercules X-1 from evolution of RXTE X-ray pulse profiles with phase of the 35-day cycle

    CERN Document Server

    Postnov, K; Staubert, R; Kochetkova, A; Klochkov, D; Wilms, J

    2013-01-01

    Accretion of matter onto the surface of a freely precessing NS with a complex non-dipole magnetic field can explain the change of X-ray pulse profiles of Her X-1 observed by RXTE with the phase of the 35-day cycle. We demonstrate this using all available measurements of X-ray pulse profiles in the 9-13 keV energy range obtained with the RXTE/PCA. The measured profiles guided the elaboration of a geometrical model and the definition of locations of emitting poles, arcs, and spots on the NS surface which satisfactorily reproduce the observed pulse profiles and their dependence on free precession phase. We have found that the observed trend of the times of the 35-day turn-ons on the O-C diagram, which can be approximated by a collection of consecutive linear segments around the mean value, can be described by our model by assuming a variable free precession period, with a fractional period change of about a few percent. We propose that the 2.5% changes in the free precession period that occur on time scales of s...

  2. Direct observation of the critical relaxation of polarization clusters in BaTiO3 using a pulsed x-ray laser technique.

    Science.gov (United States)

    Namikawa, K; Kishimoto, M; Nasu, K; Matsushita, E; Tai, R Z; Sukegawa, K; Yamatani, H; Hasegawa, H; Nishikino, M; Tanaka, M; Nagashima, K

    2009-11-06

    We have developed a new method to investigate the relaxation time of the dipole moment in polarization clusters in BaTiO3. Time correlation of speckle intensities was measured by the use of a double pulsed soft x-ray laser. The evolution of the relaxation time of the dipole moment near the Curie temperature (T(C)) was investigated. The maximum relaxation time (approximately 90 ps) is shown to appear at a temperature of 4.5 K above the T(C), being coincident with the one where the maximum polarization takes place. This method is widely applicable to any other critical decay processes at phase transitions.

  3. The Discovery of an Outburst and Pulsed X-ray Flux from SMC X-2 from RXTE Observations

    CERN Document Server

    Corbet, R H D; Coe, M J; Laycock, S; Handler, G

    2001-01-01

    Rossi X-ray Timing Explorer All Sky Monitor observations of SMC X-2 show that the source experienced an outburst in January to April 2000 reaching a peak luminosity of greater than ~10^38 ergs s^-1. RXTE Proportional Counter Array observations during this outburst reveal the presence of pulsations with a 2.37s period. However, optical photometry of the optical counterpart showed the source to be still significantly fainter than it was more than half a year after the outburst in the 1970s when SMC X-2 was discovered.

  4. High Brightness, High Average Current Injector Development at Cornell

    CERN Document Server

    Sinclair, C K

    2005-01-01

    Cornell University is constructing a 100 mA average current, high brightness electron injector for a planned Energy Recovery Linac (ERL) hard X-ray synchrotron radiation source. This injector will employ a very high voltage DC gun with a negative electron affinity photoemission cathode. Relatively long duration electron pulses from the photocathode will be drift bunched, and accelerated to 5-15 MeV with five two-cell, 1300 MHz superconducting cavities. The total beam power will be limited to 575 kW by the DC and RF power sources. A genetic algorithm based computational optimization of this injector has resulted in simulated rms normalized emittances of 0.1 mm-mrad at 80 pC/bunch, and 0.7 mm-mrad at 1 nC/bunch. The many technical issues and their design solutions will be discussed. Construction of the gun and the SRF cavities is well underway. The schedule for completion, and the planned measurements, will be presented.

  5. X-ray spectroscopic technique for energetic electron transport studies in short-pulse laser/plasma interactions

    Energy Technology Data Exchange (ETDEWEB)

    Tutt, T.E.

    1994-12-01

    When a solid target is irradiated by a laser beam, the material is locally heated to a high temperature and a plasma forms. The interaction of the laser with plasma can produce energetic electrons. By observing the behavior of these {open_quotes}hot{close_quotes} electrons, we hope to obtain a better understanding of Laser/Plasma Interactions. In this work we employ a layered-fluorescer technique to study the transport, and therefore the energetics, of the electrons. The plasma forms on a thin foil of metallic Pd which is bonded to thin layer of metallic Sn. Electrons formed from the plasma penetrate first the Pd and then the Sn. In both layers the energetic electrons promote inner (K) shell ionization of the metallic atoms which leads to the emission of characteristic K{sub {alpha}} x-rays of the fluorescers. By recording the x-ray spectrum emitted by the two foils, we can estimate the energy-dependent range of the electrons and their numbers.

  6. Proposal to generate 10 TW level femtosecond X-ray pulses from a baseline undulator in conventional SASE regime at the European XFEL

    Energy Technology Data Exchange (ETDEWEB)

    Serkez, Svitozar; Kocharyan, Vitali; Saldin, Evgeni; Zagorodnov, Igor [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Geloni, Gianluca [European XFEL GmbH, Hamburg (Germany)

    2013-08-15

    Output characteristics of the European XFEL have been previously studied assuming an operation point at 5 kA peak current. In this paper we explore the possibility to go well beyond such nominal peak current level. In order to illustrate the potential of the European XFEL accelerator complex we consider a bunch with 0.25 nC charge, compressed up to a peak current of 45 kA. An advantage of operating at such high peak current is the increase of the X-ray output peak power without any modification to the baseline design. Based on start-to-end simulations, we demonstrate that such high peak current, combined with undulator tapering, allows one to achieve up to a 100-fold increase in a peak power in the conventional SASE regime, compared to the nominal mode of operation. In particular, we find that 10 TW-power level, femtosecond x-ray pulses can be generated in the photon energy range between 3 keV and 5 keV, which is optimal for single biomolecule imaging. Our simulations are based on the exploitation of all the 21 cells foreseen for the SASE3 undulator beamline, and indicate that one can achieve diffraction to the desired resolution with 15 mJ (corresponding to about 3.10{sup 13} photons) in pulses of about 3 fs, in the case of a 100 nm focus at the photon energy of 3.5 keV.

  7. Effects of electron recirculation on a hard x-ray source observed during the interaction of a high intensity laser pulse with thin Au targets

    Science.gov (United States)

    Compant La Fontaine, A.; Courtois, C.; Lefebvre, E.; Bourgade, J. L.; Landoas, O.; Thorp, K.; Stoeckl, C.

    2013-12-01

    The interaction of a high intensity laser pulse on the preplasma of a high-Z solid target produced by the pulse's pedestal generates high-energy electrons. These electrons subsequently penetrate inside the solid target and produce bremsstrahlung photons, generating an x-ray source which can be used for photonuclear studies or to radiograph high area density objects. The source characteristics are compared for targets with thin (20 μm) and thick (100 μm) Au foils on the Omega EP laser at Laboratory for Laser Energetics. Simulations using the particle-in-cell code CALDER show that for a 20 μm thickness Au target, electrons perform multiple round-trips in the target under the effect of the laser ponderomotive potential and the target electrostatic potential. These relativistic electrons have random transverse displacements, with respect to the target normal, attributed to electrostatic fluctuation fields. As a result, the x-ray spot size is increased by a factor 2 for thin target compared to thick targets, in agreement with experimental results. In addition, the computed doses agree with the measured ones provided that electron recirculation in the thin target is taken into account. A dose increase by a factor 1.7 is then computed by allowing for recirculation. In the 100 μm target case, on the other hand, this effect is found to be negligible.

  8. Experimental and numerical investigations of air plasmas induced by multi-MeV pulsed X-ray from low to atmospheric pressures

    Science.gov (United States)

    Maulois, Mélissa; Ribière, Maxime; Eichwald, Olivier; Yousfi, Mohammed; Pouzalgues, Romain; Garrigues, Alain; Delbos, Christophe; Azaïs, Bruno

    2016-09-01

    This research work is devoted to the experimental and theoretical analysis of air plasmas induced by multi-MeV pulsed X-ray for a large pressure range of humid air background gas varying from 20 mbar to atmospheric pressure. The time evolution of the electron density of the air plasma is determined by electromagnetic wave absorption measurements. The measurements have uncertainties of about ±30%, taking into account the precision of the dose measurement and also the shot to shot fluctuations of the generator. The experimental electron density is obtained by comparing the measurements of the transmitted microwave signals to the calculated ones. The calculations need the knowledge of the time evolution of the electron mean energy, which is determined by a chemical kinetic model based on a reaction scheme involving 39 species interacting following 265 reactions. During the X-ray pulse, a good agreement is obtained between time evolution of the electron density obtained from absorption measurements and calculations based on the kinetic model. The relative deviation on the maximum electron density and the corresponding plasma frequency is always lower than 10%. The maximum electron density varies from 4 × 1011 to 3.5 × 1013 cm-3 between 30 mbar to atmospheric pressure, while the peak of the electron mean energy decreases from 5.64 eV to 4.27 eV in the same pressure range.

  9. Monte Carlo calculation of ion, electron, and photon spectra of xenon atoms in x-ray free-electron laser pulses

    CERN Document Server

    Son, Sang-Kil; 10.1103/PhysRevA.85.063415

    2013-01-01

    When atoms and molecules are irradiated by an x-ray free-electron laser (XFEL), they are highly ionized via a sequence of one-photon ionization and relaxation processes. To describe the ionization dynamics during XFEL pulses, a rate equation model has been employed. Even though this model is straightforward for the case of light atoms, it generates a huge number of coupled rate equations for heavy atoms like xenon, which are not trivial to solve directly. Here, we employ the Monte Carlo method to address this problem and we investigate ionization dynamics of xenon atoms induced by XFEL pulses at a photon energy of 4500 eV. Charge state distributions, photo-/Auger electron spectra, and fluorescence spectra are presented for x-ray fluences of up to $10^{13}$ photons/$\\mu$m$^2$. With the photon energy of 4500 eV, xenon atoms can be ionized up to +44 through multiphoton absorption characterized by sequential one-photon single-electron interactions.

  10. 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.

  11. Efficient multi-keV x-ray generation from a high-Z target irradiated with a clean ultra-short laser pulse.

    Science.gov (United States)

    Zhang, Z; Nishikino, M; Nishimura, H; Kawachi, T; Pirozhkov, A S; Sagisaka, A; Orimo, S; Ogura, K; Yogo, A; Okano, Y; Ohshima, S; Fujioka, S; Kiriyama, H; Kondo, K; Shimomura, T; Kanazawa, S

    2011-02-28

    Kα line emissions from Mo and Ag plates were experimentally studied using clean, ultrahigh-intensity femtosecond laser pulses. The absolute yields of Kα x-rays at 17 keV from Mo and 22 keV from Ag were measured as a function of the laser pulse contrast ratio and irradiation intensity. Significantly enhanced Kα yields were obtained for both Mo and Ag by employing high contrast ratios and irradiances. Conversion efficiencies of 4.28×10⁻⁵/sr for Mo and 4.84×10⁻⁵/sr for Ag, the highest values obtained to date, were demonstrated with contrast ratios in the range 10⁻¹⁰ to 10⁻¹¹.

  12. PROCEEDINGS ON SYNCHROTRON RADIATION: In-situ monitoring of EuTiO3 and SrTiO3 film growth using time-resolved X-ray scattering during pulsed-laser deposition

    Science.gov (United States)

    Wang, Huan-Hua

    2009-11-01

    Time-resolved X-ray scattering was employed to in-situ monitor the epitaxial growth process of the thin films and multilayers of EuTiO3 and SrTiO3 during pulsed laser deposition. The temporal intensity oscillations of the reflected X-rays at anti-Bragg position and the transient processes following the flux pulses were observed. The temporal intensity oscillations were used to control the film thickness, and the reflectivity along the crystal truncation rod was used to measure both the film thickness and the surface/interface roughness. The primary features of the X-ray intensity oscillations were reproduced via simulating the experimental data using diffusive rate equation model. Several mechanisms of determining the X-ray intensity features were discerned.

  13. A final report to the Laboratory Directed Research and Development committee on Project 93-ERP-075: ``X-ray laser propagation and coherence: Diagnosing fast-evolving, high-density laser plasmas using X-ray lasers``

    Energy Technology Data Exchange (ETDEWEB)

    Wan, A.S.; Cauble, R.; Da Silva, L.B.; Libby, S.B.; Moreno, J.C.

    1996-02-01

    This report summarizes the major accomplishments of this three-year Laboratory Directed Research and Development (LDRD) Exploratory Research Project (ERP) entitled ``X-ray Laser Propagation and Coherence: Diagnosing Fast-evolving, High-density Laser Plasmas Using X-ray Lasers,`` tracking code 93-ERP-075. The most significant accomplishment of this project is the demonstration of a new laser plasma diagnostic: a soft x-ray Mach-Zehnder interferometer using a neonlike yttrium x-ray laser at 155 {angstrom} as the probe source. Detailed comparisons of absolute two-dimensional electron density profiles obtained from soft x-ray laser interferograms and profiles obtained from radiation hydrodynamics codes, such as LASNEX, will allow us to validate and benchmark complex numerical models used to study the physics of laser-plasma interactions. Thus the development of soft x-ray interferometry technique provides a mechanism to probe the deficiencies of the numerical models and is an important tool for, the high-energy density physics and science-based stockpile stewardship programs. The authors have used the soft x-ray interferometer to study a number of high-density, fast evolving, laser-produced plasmas, such as the dynamics of exploding foils and colliding plasmas. They are pursuing the application of the soft x-ray interferometer to study ICF-relevant plasmas, such as capsules and hohlraums, on the Nova 10-beam facility. They have also studied the development of enhanced-coherence, shorter-pulse-duration, and high-brightness x-ray lasers. The utilization of improved x-ray laser sources can ultimately enable them to obtain three-dimensional holographic images of laser-produced plasmas.

  14. Development and characterization of a tunable ultrafast X-ray source via inverse-Compton-scattering

    Energy Technology Data Exchange (ETDEWEB)

    Jochmann, Axel

    2014-07-01

    Ultrashort, nearly monochromatic hard X-ray pulses enrich the understanding of the dynamics and function of matter, e.g., the motion of atomic structures associated with ultrafast phase transitions, structural dynamics and (bio)chemical reactions. Inverse Compton backscattering of intense laser pulses from relativistic electrons not only allows for the generation of bright X-ray pulses which can be used in a pump-probe experiment, but also for the investigation of the electron beam dynamics at the interaction point. The focus of this PhD work lies on the detailed understanding of the kinematics during the interaction of the relativistic electron bunch and the laser pulse in order to quantify the influence of various experiment parameters on the emitted X-ray radiation. The experiment was conducted at the ELBE center for high power radiation sources using the ELBE superconducting linear accelerator and the DRACO Ti:sapphire laser system. The combination of both these state-of-the-art apparatuses guaranteed the control and stability of the interacting beam parameters throughout the measurement. The emitted X-ray spectra were detected with a pixelated detector of 1024 by 256 elements (each 26μm by 26μm) to achieve an unprecedented spatial and energy resolution for a full characterization of the emitted spectrum to reveal parameter influences and correlations of both interacting beams. In this work the influence of the electron beam energy, electron beam emittance, the laser bandwidth and the energy-anglecorrelation on the spectra of the backscattered X-rays is quantified. A rigorous statistical analysis comparing experimental data to ab-initio 3D simulations enabled, e.g., the extraction of the angular distribution of electrons with 1.5% accuracy and, in total, provides predictive capability for the future high brightness hard X-ray source PHOENIX (Photon electron collider for Narrow bandwidth Intense X-rays) and potential all optical gamma-ray sources. The results

  15. High-power laser-driven source of ultra-short X-ray and gamma-ray pulses

    Energy Technology Data Exchange (ETDEWEB)

    Esirkepov, T.Zh.; Bulanov, S.V.; Pirozhkov, A.S.; Kando, M. [Advanced Photon Research Center, Japan Atomic Energy Agency, Kyoto (Japan); Zhidkov, A.G. [Central Research Institute of Electric Power Industry, Yokosuka-shi, Kanagawa-Ken (Japan)

    2009-11-15

    A novel ultra-bright high-intensity source of X-ray and gamma radiation is suggested. It is based on the double Doppler effect, where a relativistic flying mirror reflects a counter-propagating electromagnetic radiation causing its frequency multiplication and intensification, and on the inverse double Doppler effect, where the mirror acquires energy from an ultra-intense co-propagating electromagnetic wave. The role of the flying mirror is played by a high-density thin plasma slab accelerating in the radiation pressure dominant regime. Frequencies of high harmonics generated at the flying mirror by a relativistically strong counter-propagating radiation undergo multiplication with the same factor as the fundamental frequency of the reflected radiation, approximately equal to the quadruple of the square of the mirror Lorentz factor. (authors)

  16. High-power laser-driven source of ultra-short X-ray and gamma-ray pulses

    Science.gov (United States)

    Esirkepov, T. Zh.; Bulanov, S. V.; Zhidkov, A. G.; Pirozhkov, A. S.; Kando, M.

    2009-11-01

    A novel ultra-bright high-intensity source of X-ray and gamma radiation is suggested. It is based on the double Doppler effect, where a relativistic flying mirror reflects a counter-propagating electromagnetic radiation causing its frequency multiplication and intensification, and on the inverse double Doppler effect, where the mirror acquires energy from an ultra-intense co-propagating electromagnetic wave. The role of the flying mirror is played by a high-density thin plasma slab accelerating in the radiation pressure dominant regime. Frequencies of high harmonics generated at the flying mirror by a relativistically strong counter-propagating radiation udergo multiplication with the same factor as the fundamental frequency of the reflected radiation, approximately equal to the quadruple of the square of the mirror Lorentz factor.

  17. Laser plasma x-ray source for ultrafast time-resolved x-ray absorption spectroscopy.

    Science.gov (United States)

    Miaja-Avila, L; O'Neil, G C; Uhlig, J; Cromer, C L; Dowell, M L; Jimenez, R; Hoover, A S; Silverman, K L; Ullom, J N

    2015-03-01

    We describe a laser-driven x-ray plasma source designed for ultrafast x-ray absorption spectroscopy. The source is comprised of a 1 kHz, 20 W, femtosecond pulsed infrared laser and a water target. We present the x-ray spectra as a function of laser energy and pulse duration. Additionally, we investigate the plasma temperature and photon flux as we vary the laser energy. We obtain a 75 μm FWHM x-ray spot size, containing ∼10(6) photons/s, by focusing the produced x-rays with a polycapillary optic. Since the acquisition of x-ray absorption spectra requires the averaging of measurements from >10(7) laser pulses, we also present data on the source stability, including single pulse measurements of the x-ray yield and the x-ray spectral shape. In single pulse measurements, the x-ray flux has a measured standard deviation of 8%, where the laser pointing is the main cause of variability. Further, we show that the variability in x-ray spectral shape from single pulses is low, thus justifying the combining of x-rays obtained from different laser pulses into a single spectrum. Finally, we show a static x-ray absorption spectrum of a ferrioxalate solution as detected by a microcalorimeter array. Altogether, our results demonstrate that this water-jet based plasma source is a suitable candidate for laboratory-based time-resolved x-ray absorption spectroscopy experiments.

  18. Laser plasma x-ray source for ultrafast time-resolved x-ray absorption spectroscopy

    Directory of Open Access Journals (Sweden)

    L. Miaja-Avila

    2015-03-01

    Full Text Available We describe a laser-driven x-ray plasma source designed for ultrafast x-ray absorption spectroscopy. The source is comprised of a 1 kHz, 20 W, femtosecond pulsed infrared laser and a water target. We present the x-ray spectra as a function of laser energy and pulse duration. Additionally, we investigate the plasma temperature and photon flux as we vary the laser energy. We obtain a 75 μm FWHM x-ray spot size, containing ∼106 photons/s, by focusing the produced x-rays with a polycapillary optic. Since the acquisition of x-ray absorption spectra requires the averaging of measurements from >107 laser pulses, we also present data on the source stability, including single pulse measurements of the x-ray yield and the x-ray spectral shape. In single pulse measurements, the x-ray flux has a measured standard deviation of 8%, where the laser pointing is the main cause of variability. Further, we show that the variability in x-ray spectral shape from single pulses is low, thus justifying the combining of x-rays obtained from different laser pulses into a single spectrum. Finally, we show a static x-ray absorption spectrum of a ferrioxalate solution as detected by a microcalorimeter array. Altogether, our results demonstrate that this water-jet based plasma source is a suitable candidate for laboratory-based time-resolved x-ray absorption spectroscopy experiments.

  19. 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.

  20. 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 ...

  1. 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 ...

  2. Study of x-rays produced from debris-free sources with Ar, Kr and Kr/Ar mixture linear gas jets irradiated by UNR Leopard laser beam with fs and ns pulse duration

    Science.gov (United States)

    Kantsyrev, V. L.; Schultz, K. A.; Shlyaptseva, V. V.; Safronova, A. S.; Shrestha, I. K.; Petrov, G. M.; Moschella, J. J.; Petkov, E. E.; Stafford, A.; Cooper, M. C.; Weller, M. E.; Cline, W.; Wiewior, P.; Chalyy, O.

    2016-06-01

    Experiments of x-ray emission from Ar, Kr, and Ar/Kr gas jet mixture were performed at the UNR Leopard Laser Facility operated with 350 fs pulses at laser intensity of 2 × 1019 W/cm2 and 0.8 ns pulses at an intensity of 1016 W/cm2. Debris free x-ray source with supersonic linear nozzle generated clusters/monomer jet with an average density of ≥1019 cm-3 was compared to cylindrical tube subsonic nozzle, which produced only monomer jet with average density 1.5-2 times higher. The linear (elongated) cluster/gas jet provides the capability to study x-ray yield anisotropy and laser beam self-focusing with plasma channel formation that are interconnecting with efficient x-ray generation. Diagnostics include x-ray diodes, pinhole cameras and spectrometers. It was observed that the emission in the 1-9 keV spectral region was strongly anisotropic depending on the directions of laser beam polarization for sub-ps laser pulse and supersonic linear jet. The energy yield in the 1-3 keV region produced by a linear nozzle was an order of magnitude higher than from a tube nozzle. Non-LTE models and 3D molecular dynamic simulations of Ar and Kr clusters irradiated by sub-ps laser pulses have been implemented to analyze obtained data. A potential evidence of electron beam generation in jets' plasma was discussed. Note that the described debris-free gas-puff x-ray source can generate x-ray pulses in a high repetition regime. This is a great advantage compared to solid laser targets.

  3. Proposal to generate 10 TW level femtosecond x-ray pulses from a baseline undulator in conventional SASE regime at the European XFEL

    CERN Document Server

    Serkez, Svitozar; Saldin, Evgeni; Zagorodnov, Igor; Geloni, Gianluca

    2013-01-01

    Output characteristics of the European XFEL have been previously studied assuming an operation point at 5 kA peak current. In this paper we explore the possibility to go well beyond such nominal peak current level. In order to illustrate the potential of the European XFEL accelerator complex we consider a bunch with 0.25 nC charge, compressed up to a peak current of 45 kA. An advantage of operating at such high peak current is the increase of the x-ray output peak power without any modification to the baseline design. Based on start-to-end simulations, we demonstrate that such high peak current, combined with undulator tapering, allows one to achieve up to a 100-fold increase in a peak power in the conventional SASE regime, compared to the nominal mode of operation. In particular, we find that 10 TW-power level, femtosecond x-ray pulses can be generated in the photon energy range between 3 keV and 5 keV, which is optimal for single biomolecule imaging. Our simulations are based on the exploitation of all the ...

  4. Laser-driven plasma wakefield electron acceleration and coherent femtosecond pulse generation in X-ray and gamma ranges

    Science.gov (United States)

    Trunov, V. I.; Lotov, K. V.; Gubin, K. V.; Pestryakov, E. V.; Bagayev, S. N.; Logachev, P. V.

    2017-01-01

    The laser wakefield acceleration (LWFA) of electrons in capillaries and gas jets followed by inverse Compton scattering of high intensity femtosecond laser pulses is discussed. The drive and scattered pulses will be produced by the two-channel multi-terawatt laser system developed in ILP SB RAS.

  5. 600 eV falcon-linac thomson x-ray source

    Energy Technology Data Exchange (ETDEWEB)

    Crane, J K; LeSage, G P; Ditmire, T; Cross, R; Wharton, K; Moffitt, K; Cowan, T E; Hays, G; Tsai, V; Anderson, G; Shuttlesworth, R; Springer, P

    2000-12-15

    The advent of 3rd generation light sources such as the Advanced Light Source (ALS) at LBL, and the Advanced Photon Source at Argonne, have produced a revolution in x-ray probing of dense matter during the past decade. These machines use electron-synchrotrons in conjunction with undulator stages to produce 100 psec x-ray pulses with photon energies of several kiloelectronvolts (keV). The applications for x-ray probing of matter are numerous and diverse with experiments in medicine and biology, semiconductors and materials science, and plasma and solid state physics. In spite of the success of the 3rd generation light sources there is strong motivation to push the capabilities of x-ray probing into new realms, requiring shorter pulses, higher brightness and harder x-rays. A 4th generation light source, the Linac Coherent Light Source (LCLS), is being considered at the Stanford Linear Accelerator [1]. The LCLS will produce multi-kilovolt x-rays of subpicosecond duration that are 10 orders of magnitude brighter than today's 3rd generation light sources.[1] Although the LCLS will provide unprecedented capability for performing time-resolved x-ray probing of ultrafast phenomena at solid densities, this machine will not be completed for many years. In the meantime there is a serious need for an ultrashort-pulse, high-brightness, hard x-ray source that is capable of probing deep into high-Z solid materials to measure dynamic effects that occur on picosecond time scales. Such an instrument would be ideal for probing the effects of shock propagation in solids using Bragg and Laue diffraction. These techniques can be used to look at phase transitions, melting and recrystallization, and the propagation of defects and dislocations well below the surface in solid materials. [2] These types of dynamic phenomena undermine the mechanical properties of metals and are of general interest in solid state physics, materials science, metallurgy, and have specific relevance to

  6. Proposal for a scheme to generate 10 TW-Level femtosecond X-ray pulses for imaging single protein molecules at the European XFEL

    Energy Technology Data Exchange (ETDEWEB)

    Serkez, Svitozar; Kocharyan, Vitali; Saldin, Evgeni; Zagorodnov, Igor [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Geloni, Gianluca [European XFEL GmbH, Hamburg (Germany); Yefanov, Oleksander [Center for Free-Electron Laser Science, Hamburg (Germany)

    2013-06-15

    Single biomolecular imaging using XFEL radiation is an emerging method for protein structure determination using the ''diffraction before destruction'' method at near atomic resolution. Crucial parameters for such bio-imaging experiments are photon energy range, peak power, pulse duration, and transverse coherence. The largest diffraction signals are achieved at the longest wavelength that supports a given resolution, which should be better than 0.3 nm. We propose a configuration which combines self-seeding and undulator tapering techniques with the emittance-spoiler method in order to increase the XFEL output peak power and to shorten the pulse duration up to a level sufficient for performing bio-imaging of single protein molecules at the optimal photon energy range, i.e. around 4 keV. Experiments at the LCLS confirmed the feasibility of these three new techniques. Based on start-to-end simulations we demonstrate that self-seeding, combined with undulator tapering, allows one to achieve up to a 100-fold increase in peak-power. A slotted foil in the last bunch compressor is added for X-ray pulse duration control. Simulations indicate that one can achieve diffraction to the desired resolution with 50 mJ (corresponding to 10{sup 14} photons) per 10 fs pulse at 3.5 keV photon energy in a 100 nm focus. This result is exemplified using the photosystem I membrane protein as a case study.

  7. Monte Carlo Simulations of High-speed, Time-gated MCP-based X-ray Detectors: Saturation Effects in DC and Pulsed Modes and Detector Dynamic Range

    Energy Technology Data Exchange (ETDEWEB)

    Craig Kruschwitz, Ming Wu, Ken Moy, Greg Rochau

    2008-10-31

    We present here results of continued efforts to understand the performance of microchannel plate (MCP)–based, high-speed, gated, x-ray detectors. This work involves the continued improvement of a Monte Carlo simulation code to describe MCP performance coupled with experimental efforts to better characterize such detectors. Our goal is a quantitative description of MCP saturation behavior in both static and pulsed modes. We have developed a new model of charge buildup on the walls of the MCP channels and measured its effect on MCP gain. The results are compared to experimental data obtained with a short-pulse, high-intensity ultraviolet laser; these results clearly demonstrate MCP saturation behavior in both DC and pulsed modes. The simulations compare favorably to the experimental results. The dynamic range of the detectors in pulsed operation is of particular interest when fielding an MCP–based camera. By adjusting the laser flux we study the linear range of the camera. These results, too, are compared to our simulations.

  8. X-ray Pulsar in the Crab Nebula.

    Science.gov (United States)

    Fritz, G; Henry, R C; Meekins, J F; Chubb, T A; Friedman, H

    1969-05-09

    X-ray pulsations have been observed in the Crab Nebula at a frequency closely matching the radio and optical pulsations. About 5 percent of the total x-ray power of the nebula appears in the pulsed component. The x-ray pulsations have the form of a main pulse and an interpulse separated by about 12 milliseconds.

  9. Generation of nanosecond soft X-ray pulsed as a result of interaction of laser radiation with gas puff target; Wplyw nanosekundowych impulsow miekkiego promieniowania rentgenowskiego w wyniku oddzialywania promieniowania laserowego z impulsowa tarcza gazowa

    Energy Technology Data Exchange (ETDEWEB)

    Fiedorowicz, H.; Patron, Z.; Bartnik, A.; Parys, P. [Wojskowa Akademia Techniczna, Warsaw (Poland)

    1995-10-01

    A new method of generation of nanosecond soft x-ray pulsed with a photon energy around 1 keV is presented. X-rays are generated in a high-temperature plasma, which is created as a result of interaction of Nd:glass laser radiation with a gas puff target. The target was obtained by puffing a small amount of gas, through the nozzle, into the vacuum chamber, by means of a pressure electromagnetic valve. The pulses of laser radiation with the pulse duration of 1 ns and energy up to 15 J, generated in the system of a high-power Nd:glass laser, were for the target heating. Spatial, spectral and temporal measurements of X-ray emission have shown that the high-intensity soft X-ray are generated as a result of the interaction of nanosecond pulses of Nd:glass laser radiation with the gas puff target. High efficiency of X-ray generation is suggested to be related to the effect of condensation of the gas, outflowing from the valve nozzle and, in effect, to the interaction of laser radiation with matter in a form of aerosol. (author). 55 refs, 5 figs.

  10. 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.

  11. A cascaded model of spectral distortions due to spectral response effects and pulse pileup effects in a photon-counting x-ray detector for CT

    Energy Technology Data Exchange (ETDEWEB)

    Cammin, Jochen, E-mail: jcammin1@jhmi.edu, E-mail: ktaguchi@jhmi.edu; Taguchi, Katsuyuki, E-mail: jcammin1@jhmi.edu, E-mail: ktaguchi@jhmi.edu [Division of Medical Imaging Physics, The Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, Maryland 21287 (United States); Xu, Jennifer [Department of Biomedical Engineering, Johns Hopkins University, Baltimore, Maryland 21287 (United States); Barber, William C.; Iwanczyk, Jan S.; Hartsough, Neal E. [DxRay, Inc., Northridge, California 91324 (United States)

    2014-04-15

    Purpose: Energy discriminating, photon-counting detectors (PCDs) are an emerging technology for computed tomography (CT) with various potential benefits for clinical CT. The photon energies measured by PCDs can be distorted due to the interactions of a photon with the detector and the interaction of multiple coincident photons. These effects result in distorted recorded x-ray spectra which may lead to artifacts in reconstructed CT images and inaccuracies in tissue identification. Model-based compensation techniques have the potential to account for the distortion effects. This approach requires only a small number of parameters and is applicable to a wide range of spectra and count rates, but it needs an accurate model of the spectral distortions occurring in PCDs. The purpose of this study was to develop a model of those spectral distortions and to evaluate the model using a PCD (model DXMCT-1; DxRay, Inc., Northridge, CA) and various x-ray spectra in a wide range of count rates. Methods: The authors hypothesize that the complex phenomena of spectral distortions can be modeled by: (1) separating them into count-rate independent factors that we call the spectral response effects (SRE), and count-rate dependent factors that we call the pulse pileup effects (PPE), (2) developing separate models for SRE and PPE, and (3) cascading the SRE and PPE models into a combined SRE+PPE model that describes PCD distortions at both low and high count rates. The SRE model describes the probability distribution of the recorded spectrum, with a photo peak and a continuum tail, given the incident photon energy. Model parameters were obtained from calibration measurements with three radioisotopes and then interpolated linearly for other energies. The PPE model used was developed in the authors’ previous work [K. Taguchi et al., “Modeling the performance of a photon counting x-ray detector for CT: Energy response and pulse pileup effects,” Med. Phys. 38(2), 1089–1102 (2011

  12. 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.

  13. 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...

  14. Cargo and Container X-Ray Inspection with Intra-Pulse Multi-Energy Method for Material Discrimination

    Science.gov (United States)

    Saverskiy, Aleksandr Y.; Dinca, Dan-Cristian; Rommel, J. Martin

    The Intra-Pulse Multi-Energy (IPME) method of material discrimination mitigates main disadvantages of the traditional "interlaced" approach: ambiguity caused by sampling different regions of cargo and reduction of effective scanning speed. A novel concept of creating multi-energy probing pulses using a standing-wave structure allows maintaining a constant energy spectrum while changing the time duration of each sub-pulse and thus enables adaptive cargo inspection. Depending on the cargo density, the dose delivered to the inspected object is optimized for best material discrimination, maximum material penetration, or lowest dose to cargo. A model based on Monte-Carlo simulation and experimental reference points were developed for the optimization of inspection conditions.

  15. X-ray induced optical reflectivity

    Directory of Open Access Journals (Sweden)

    Stephen M. Durbin

    2012-12-01

    Full Text Available The change in optical reflectivity induced by intense x-ray pulses can now be used to study ultrafast many body responses in solids in the femtosecond time domain. X-ray absorption creates photoelectrons and core level holes subsequently filled by Auger or fluorescence processes, and these excitations ultimately add conduction and valence band carriers that perturb optical reflectivity. Optical absorption associated with band filling and band gap narrowing is shown to explain the basic features found in recent measurements on an insulator (silicon nitride, Si3N4, a semiconductor (gallium arsenide, GaAs, and a metal (gold, Au, obtained with ∼100 fs x-ray pulses at 500-2000 eV and probed with 800 nm laser pulses. In particular GaAs exhibits an abrupt drop in reflectivity, persisting only for a time comparable to the x-ray excitation pulse duration, consistent with prompt band gap narrowing.

  16. 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.

  17. Self-amplified spontaneous emission FEL with energy-chirped electron beam and its application for generation of attosecond x-ray pulses

    Directory of Open Access Journals (Sweden)

    E. L. Saldin

    2006-05-01

    Full Text Available Influence of a linear energy chirp in the electron beam on a self-amplified spontaneous emission (SASE Free Electron Laser (FEL operation is studied analytically and numerically using a 1D model. Analytical results are based on the theoretical background developed by Krinsky and Huang [Phys. Rev. ST Accel. Beams 6, 050702 (2003PRABFM1098-4402]. Explicit expressions for Green’s functions and for output power of a SASE FEL are obtained for the high-gain linear regime in the limits of small and large energy chirp parameters. Saturation length and power versus energy chirp parameter are calculated numerically. It is shown that the effect of linear energy chirp on FEL gain is equivalent to the linear undulator tapering (or linear energy variation along the undulator. A consequence of this fact is a possibility to perfectly compensate FEL gain degradation, caused by the energy chirp, by means of the undulator tapering independently of the value of the energy chirp parameter. An application of this effect for generation of attosecond pulses from a hard x-ray FEL is proposed. Strong energy modulation within a short slice of an electron bunch is produced by a few-cycle optical laser pulse in a short undulator, placed in front of the main undulator. Gain degradation within this slice is compensated by an appropriate undulator taper while the rest of the bunch suffers from this taper and does not lase. Three-dimensional simulations predict that short (200 attoseconds high-power (up to 100 GW pulses can be produced in Angstrom wavelength range with a high degree of contrast. A possibility to reduce pulse duration to sub-100 attosecond scale is discussed.

  18. Photoionized plasmas induced in neon with extreme ultraviolet and soft X-ray pulses produced using low and high energy laser systems

    Energy Technology Data Exchange (ETDEWEB)

    Bartnik, A.; Wachulak, P.; Fok, T.; Węgrzyński, Ł.; Fiedorowicz, H. [Institute of Optoelectronics, Military University of Technology, Kaliskiego 2, 00-908 Warsaw (Poland); Pisarczyk, T.; Chodukowski, T.; Kalinowska, Z. [Institute of Plasma Physics and Laser Microfusion, 23 Hery St., 00-908 Warsaw (Poland); Dudzak, R.; Dostal, J.; Krousky, E.; Skala, J.; Ullschmied, J.; Hrebicek, J.; Medrik, T. [Institute of Plasma Physics ASCR, Prague, Czech Republic and Institute of Physics ASCR, Prague (Czech Republic)

    2015-04-15

    A comparative study of photoionized plasmas created by two soft X-ray and extreme ultraviolet (SXR/EUV) laser plasma sources with different parameters is presented. The two sources are based on double-stream Xe/He gas-puff targets irradiated with high (500 J/0.3 ns) and low energy (10 J/1 ns) laser pulses. In both cases, the SXR/EUV beam irradiated the gas stream, injected into a vacuum chamber synchronously with the radiation pulse. Irradiation of gases resulted in formation of photoionized plasmas emitting radiation in the SXR/EUV range. The measured Ne plasma radiation spectra are dominated by emission lines corresponding to radiative transitions in singly charged ions. A significant difference concerns origin of the lines: K-shell or L-shell emissions occur in case of the high and low energy irradiating system, respectively. In high energy system, the electron density measurements were also performed by laser interferometry, employing a femtosecond laser system. A maximum electron density for Ne plasma reached the value of 2·10{sup 18 }cm{sup −3}. For the low energy system, a detection limit was too high for the interferometric measurements, thus only an upper estimation for electron density could be made.

  19. 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

  20. Extremely High Current, High-Brightness Energy Recovery Linac

    CERN Document Server

    Ben-Zvi, Ilan; Beavis, Dana; Blaskiewicz, Michael; Bluem, Hans; Brennan, Joseph M; Burger, Al; Burrill, Andrew; Calaga, Rama; Cameron, Peter; Chang, Xiangyun; Cole, Michael; Connolly, Roger; Delayen, Jean R; Favale, Anthony; Gassner, David M; Grimes, Jacob T; Hahn, Harald; Hershcovitch, Ady; Holmes, Douglas; Hseuh Hsiao Chaun; Johnson, Peter; Kayran, Dmitry; Kewisch, Jorg; Kneisel, Peter; Lambiase, Robert; Litvinenko, Vladimir N; McIntyre, Gary; Meng, Wuzheng; Nehring, Thomas; Nicoletti, Tony; Oerter, Brian; Pate, David; Phillips, Larry; Preble, Joseph P; Rank, Jim; Rao, Triveni; Rathke, John; Roser, Thomas; Russo, Thomas; Scaduto, Joseph; Schultheiss, Tom; Segalov, Zvi; Smith, Kevin T; Todd, Alan M M; Warren-Funk, L; Williams, Neville; Wu, Kuo-Chen; Yakimenko, Vitaly; Yip, Kin; Zaltsman, Alex; Zhao, Yongxiang

    2005-01-01

    Next generation ERL light-sources, high-energy electron coolers, high-power Free-Electron Lasers, powerful Compton X-ray sources and many other accelerators were made possible by the emerging technology of high-power, high-brightness electron beams. In order to get the anticipated performance level of ampere-class currents, many technological barriers are yet to be broken. BNL's Collider-Accelerator Department is pursuing some of these technologies for its electron cooling of RHIC application, as well as a possible future electron-hadron collider. We will describe work on CW, high-current and high-brightness electron beams. This will include a description of a superconducting, laser-photocathode RF gun and an accelerator cavity capable of producing low emittance (about 1 micron rms normalized) one nano-Coulomb bunches at currents of the order of one ampere average.

  1. 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 ...

  2. 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 ...

  3. 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.

  4. 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.

  5. Femtosecond X-ray Absorption Spectroscopy at a Hard X-ray Free Electron Laser

    DEFF Research Database (Denmark)

    Lemke, Henrik T.; Bressler, Christian; Chen, Lin X.

    2013-01-01

    X-ray free electron lasers (XFELs) deliver short (<100 fs) and intense (similar to 10(12) photons) pulses of hard X-rays, making them excellent sources for time-resolved studies. Here we show that, despite the inherent instabilities of current (SASE based) XFELs, they can be used for measuring hi...

  6. Aerosol Imaging with a Soft X-ray Free Electron Laser

    Energy Technology Data Exchange (ETDEWEB)

    Bogan, Michael J.; /SLAC /LLNL, Livermore; Boutet, Sebastien; /SLAC; Chapman, Henry N.; /DESY /Hamburg U.; Marchesini, Stefano; /LBL, Berkeley; Barty, Anton; Benner, W.Henry /LLNL, Livermore; Rohner, Urs; /LLNL, Livermore /TOFWERK AG; Frank, Matthias; Hau-Riege, Stefan P.; /LLNL, Livermore; Bajt, Sasa; /DESY; Woods, Bruce; /LLNL, Livermore; Seibert, M.M.; Iwan, Bianca; Timneanu, Nicusor; Hajdu, Janos; /Uppsala U.; Schulz, Joachim; /DESY

    2011-08-22

    Lasers have long played a critical role in the advancement of aerosol science. A new regime of ultrafast laser technology has recently be realized, the world's first soft xray free electron laser. The Free electron LASer in Hamburg, FLASH, user facility produces a steady source of 10 femtosecond pulses of 7-32 nm x-rays with 10{sub 12} photons per pulse. The high brightness, short wavelength, and high repetition rate (>500 pulses per second) of this laser offers unique capabilities for aerosol characterization. Here we use FLASH to perform the highest resolution imaging of single PM2.5 aerosol particles in flight to date. We resolve to 35 nm the morphology of fibrous and aggregated spherical carbonaceous nanoparticles that existed for less than two milliseconds in vacuum. Our result opens the possibility for high spatialand time-resolved single particle aerosol dynamics studies, filling a critical technological need in aerosol science.

  7. Near-Edge X-Ray Absorption Fine Structure of Ultrananocrystalline Diamond/Hydrogenated Amorphous Carbon Films Prepared by Pulsed Laser Deposition

    Directory of Open Access Journals (Sweden)

    Shinya Ohmagari

    2009-01-01

    Full Text Available The atomic bonding configuration of ultrananocrystalline diamond (UNCD/hydrogenated amorphous carbon (a-C:H films prepared by pulsed laser ablation of graphite in a hydrogen atmosphere was examined by near-edge X-ray absorption fine structure spectroscopy. The measured spectra were decomposed with simple component spectra, and they were analyzed in detail. As compared to the a-C:H films deposited at room substrate-temperature, the UNCD/a-C:H and nonhydrogenated amorphous carbon (a-C films deposited at a substrate-temperature of 550∘C exhibited enhanced ∗ and ∗C≡C peaks. At the elevated substrate-temperature, the ∗ and ∗C≡C bonds formation is enhanced while the ∗C–H and ∗C–C bonds formation is suppressed. The UNCD/a-C:H film showed a larger ∗C–C peak than the a-C film deposited at the same elevated substrate-temperature in vacuum. We believe that the intense ∗C–C peak is evidently responsible for UNCD crystallites existence in the film.

  8. Pulsed supercritical synthesis of anatase TiO₂ nanoparticles in a water-isopropanol mixture studied by in situ powder X-ray diffraction.

    Science.gov (United States)

    Rostgaard Eltzholtz, Jakob; Tyrsted, Christoffer; Ørnsbjerg Jensen, Kirsten Marie; Bremholm, Martin; Christensen, Mogens; Becker-Christensen, Jacob; Brummerstedt Iversen, Bo

    2013-03-21

    A new step in supercritical nanoparticle synthesis, the pulsed supercritical synthesis reactor, is investigated in situ using synchrotron powder X-ray diffraction (PXRD) to understand the formation of nanoparticles in real time. This eliminates the common problem of transferring information gained during in situ studies to subsequent laboratory reactor conditions. As a proof of principle, anatase titania nanoparticles were synthesized in a 50/50 mixture of water and isopropanol near and above the critical point of water (P = 250 bar, T = 300, 350, 400, 450, 500 and 550 °C). The evolution of the reaction product was followed by sequentially recording PXRD patterns with a time resolution of less than two seconds. The crystallite size of titania is found to depend on both temperature and residence time, and increasing either parameter leads to larger crystallites. A simple adjustment of either temperature or residence time provides a direct method for gram scale production of anatase nanoparticles of average crystallite sizes between 7 and 35 nm, thus giving the option of synthesizing tailor-made nanoparticles. Modeling of the in situ growth curves using an Avrami growth model gave an activation energy of 66(19) kJ mol(-1) for the initial crystallization. The in situ PXRD data also provide direct information about the size dependent macrostrain in the nanoparticles and with decreasing crystallite size the unit cell contracts, especially along the c-direction. This agrees well with previous ex situ results obtained for hydrothermal synthesis of titania nanoparticles.

  9. High brightness semiconductor lasers with reduced filamentation

    DEFF Research Database (Denmark)

    McInerney, John; O'Brien, Peter.; Skovgaard, Peter M. W.;

    1999-01-01

    High brightness semiconductor lasers have applications in spectroscopy, fiber lasers, manufacturing and materials processing, medicine and free space communication or energy transfer. The main difficulty associated with high brightness is that, because of COD, high power requires a large aperture...

  10. 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.

  11. 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.

  12. 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

  13. 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 ...

  14. Scheme for Generation of Single 100 GW 300-as Pulse in the X-ray SASE FEL with the Use of a Few Cycles Optical Pulse from Ti sapphire Laser System

    CERN Document Server

    Saldin, Evgeny L; Yurkov, Mikhail V

    2004-01-01

    Femtosecond optical pulse interacts with the electron beam in the two-period undulator and produces energy modulation within a slice of the electron bunch. Then the electron beam enters the first part of the X-ray undulator and produces SASE radiation with 100 MW-level power. Due to energy modulation the frequency is correlated to the longitudinal position, and the largest frequency offset corresponds to a single-spike pulse in the time domain which is confined to one half-oscillation period near the central peak electron energy. After the first undulator the electron beam is guided through a magnetic delay which we use to position the X-ray spike with the largest frequency offset at the "fresh" part of the electron bunch. After the chicane the electron beam and the radiation enter the second undulator which is resonant with the offset frequency where only a single (300 as duration) spike grows rapidly. The final part of the undulator is a tapered section allowing to achieve maximum output power 100-150 GW in...

  15. High Brightness Neutron Source for Radiography

    Energy Technology Data Exchange (ETDEWEB)

    Cremer, J. T.; Piestrup, Melvin, A.; Gary, Charles, K.; Harris, Jack, L. Williams, David, J.; Jones, Glenn, E.; Vainionpaa, J. , H.; Fuller, Michael, J.; Rothbart, George, H.; Kwan, J., W.; Ludewigt, B., A.; Gough, R.., A..; Reijonen, Jani; Leung, Ka-Ngo

    2008-12-08

    This research and development program was designed to improve nondestructive evaluation of large mechanical objects by providing both fast and thermal neutron sources for radiography. Neutron radiography permits inspection inside objects that x-rays cannot penetrate and permits imaging of corrosion and cracks in low-density materials. Discovering of fatigue cracks and corrosion in piping without the necessity of insulation removal is possible. Neutron radiography sources can provide for the nondestructive testing interests of commercial and military aircraft, public utilities and petrochemical organizations. Three neutron prototype neutron generators were designed and fabricated based on original research done at the Lawrence Berkeley National Laboratory (LBNL). The research and development of these generators was successfully continued by LBNL and Adelphi Technology Inc. under this STTR. The original design goals of high neutron yield and generator robustness have been achieved, using new technology developed under this grant. In one prototype generator, the fast neutron yield and brightness was roughly 10 times larger than previously marketed neutron generators using the same deuterium-deuterium reaction. In another generator, we integrate a moderator with a fast neutron source, resulting in a high brightness thermal neutron generator. The moderator acts as both conventional moderator and mechanical and electrical support structure for the generator and effectively mimics a nuclear reactor. In addition to the new prototype generators, an entirely new plasma ion source for neutron production was developed. First developed by LBNL, this source uses a spiral antenna to more efficiently couple the RF radiation into the plasma, reducing the required gas pressure so that the generator head can be completely sealed, permitting the possible use of tritium gas. This also permits the generator to use the deuterium-tritium reaction to produce 14-MeV neutrons with increases

  16. 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 ...

  17. 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 ...

  18. 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 ...

  19. 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 ...

  20. 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. ...

  1. 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 ...

  2. 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 ...

  3. 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)

  4. 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 ...

  5. 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)

  6. 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 ...

  7. 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 ...

  8. Capacitor discharges, magnetohydrodynamics, X-rays, ultrasonics

    CERN Document Server

    Früngel, Frank B A

    1965-01-01

    High Speed Pulse Technology, Volume 1: Capacitor Discharges - Magnetohydrodynamics - X-Rays - Ultrasonics deals with the theoretical and engineering problems that arise in the capacitor discharge technique.This book discusses the characteristics of dielectric material, symmetrical switch tubes with mercury filling, and compensation conductor forms. The transformed discharge for highest current peaks, ignition transformer for internal combustion engines, and X-ray irradiation of subjects in mechanical motion are also elaborated. This text likewise covers the transformed capacitor discharge in w

  9. X-ray induced optical reflectivity

    OpenAIRE

    2012-01-01

    The change in optical reflectivity induced by intense x-ray pulses can now be used to study ultrafast many body responses in solids in the femtosecond time domain. X-ray absorption creates photoelectrons and core level holes subsequently filled by Auger or fluorescence processes, and these excitations ultimately add conduction and valence band carriers that perturb optical reflectivity. Optical absorption associated with band filling and band gap narrowing is shown to explain the basic featur...

  10. 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 ...

  11. 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 ...

  12. 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 ...

  13. 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 ...

  14. 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 ...

  15. Elimination of X-Ray Diffraction through Stimulated X-Ray Transmission.

    Science.gov (United States)

    Wu, B; Wang, T; Graves, C E; Zhu, D; Schlotter, W F; Turner, J J; Hellwig, O; Chen, Z; Dürr, H A; Scherz, A; Stöhr, J

    2016-07-08

    X-ray diffractive imaging with laterally coherent x-ray free-electron laser (XFEL) pulses is increasingly utilized to obtain ultrafast snapshots of matter. Here we report the amazing disappearance of single-shot charge and magnetic diffraction patterns recorded with resonantly tuned, narrow bandwidth XFEL pulses. Our experimental results reveal the exquisite sensitivity of single-shot charge and magnetic diffraction patterns of a magnetic film to the onset of field-induced stimulated elastic x-ray forward scattering. The loss in diffraction contrast, measured over 3 orders of magnitude in intensity, is in remarkable quantitative agreement with a recent theory that is extended to include diffraction.

  16. Pulsed supercritical synthesis of anatase TiO2 nanoparticles in a water-isopropanol mixture studied by in situ powder X-ray diffraction

    Science.gov (United States)

    Eltzholtz, Jakob Rostgaard; Tyrsted, Christoffer; Jensen, Kirsten Marie Ørnsbjerg; Bremholm, Martin; Christensen, Mogens; Becker-Christensen, Jacob; Iversen, Bo Brummerstedt

    2013-02-01

    A new step in supercritical nanoparticle synthesis, the pulsed supercritical synthesis reactor, is investigated in situ using synchrotron powder X-ray diffraction (PXRD) to understand the formation of nanoparticles in real time. This eliminates the common problem of transferring information gained during in situ studies to subsequent laboratory reactor conditions. As a proof of principle, anatase titania nanoparticles were synthesized in a 50/50 mixture of water and isopropanol near and above the critical point of water (P = 250 bar, T = 300, 350, 400, 450, 500 and 550 °C). The evolution of the reaction product was followed by sequentially recording PXRD patterns with a time resolution of less than two seconds. The crystallite size of titania is found to depend on both temperature and residence time, and increasing either parameter leads to larger crystallites. A simple adjustment of either temperature or residence time provides a direct method for gram scale production of anatase nanoparticles of average crystallite sizes between 7 and 35 nm, thus giving the option of synthesizing tailor-made nanoparticles. Modeling of the in situ growth curves using an Avrami growth model gave an activation energy of 66(19) kJ mol-1 for the initial crystallization. The in situ PXRD data also provide direct information about the size dependent macrostrain in the nanoparticles and with decreasing crystallite size the unit cell contracts, especially along the c-direction. This agrees well with previous ex situ results obtained for hydrothermal synthesis of titania nanoparticles.A new step in supercritical nanoparticle synthesis, the pulsed supercritical synthesis reactor, is investigated in situ using synchrotron powder X-ray diffraction (PXRD) to understand the formation of nanoparticles in real time. This eliminates the common problem of transferring information gained during in situ studies to subsequent laboratory reactor conditions. As a proof of principle, anatase titania

  17. High-Flux Femtosecond X-Ray Emission from Controlled Generation of Annular Electron Beams in a Laser Wakefield Accelerator.

    Science.gov (United States)

    Zhao, T Z; Behm, K; Dong, C F; Davoine, X; Kalmykov, S Y; Petrov, V; Chvykov, V; Cummings, P; Hou, B; Maksimchuk, A; Nees, J A; Yanovsky, V; Thomas, A G R; Krushelnick, K

    2016-08-26

    Annular quasimonoenergetic electron beams with a mean energy in the range 200-400 MeV and charge on the order of several picocoulombs were generated in a laser wakefield accelerator and subsequently accelerated using a plasma afterburner in a two-stage gas cell. Generation of these beams is associated with injection occurring on the density down ramp between the stages. This well-localized injection produces a bunch of electrons performing coherent betatron oscillations in the wakefield, resulting in a significant increase in the x-ray yield. Annular electron distributions are detected in 40% of shots under optimal conditions. Simultaneous control of the pulse duration and frequency chirp enables optimization of both the energy and the energy spread of the annular beam and boosts the radiant energy per unit charge by almost an order of magnitude. These well-defined annular distributions of electrons are a promising source of high-brightness laser plasma-based x rays.

  18. A review of laser and synchrotron based X-ray sources

    Energy Technology Data Exchange (ETDEWEB)

    Smith, R. [Paris-Sud Univ., Orsay (France). LSAI; Key, M.H. [Paris-Sud Univ., Orsay (France). LSAI; Lawrence Livermore National Lab., CA (United States)

    2001-07-01

    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 summarises, for the purpose of comparison, the characteristics and near term prospects of sources based on synchrotron radiation and free electron lasers. Relative comparisons are given within charts of peak brightness. (orig.)

  19. Compact X-ray free-electron laser based on an optical undulator

    Energy Technology Data Exchange (ETDEWEB)

    Bacci, A.; Maroli, C. [Sezione di Milano INFN, Via Celoria 16, 20133 Milan (Italy); Petrillo, V. [Sezione di Milano INFN, Via Celoria 16, 20133 Milan (Italy); Universita degli Studi di Milano, Via Celoria 16, 20133 Milan (Italy)], E-mail: Petrillo@mi.infn.it; Rossi, A.R.; Serafini, L. [Sezione di Milano INFN, Via Celoria 16, 20133 Milan (Italy); Tomassini, P. [Sezione di Milano INFN, Via Celoria 16, 20133 Milan (Italy); Universita degli Studi di Pisa, Via Buonarroti, 256127 Pisa (Italy)

    2008-03-21

    The interaction between a very high-brightness electron beam and a relativistically intense optical laser pulse produces X-rays via coherent Thomson back scattering with FEL collective amplification. The phenomenon is, however, very selective, so that the characteristics of both electron and laser beam must satisfy tight requirements in terms of beam current, emittance, energy spread and laser amplitude stability within the pulse. The three-dimensional equations governing the radiation phenomena have been studied in both linear and non-linear regime and solved numerically for the particularly interesting values of wavelengths of 1 A, 1 and 12 nm. The performance of the collective Thomson source has been compared with that of an equivalent static undulator. A set of scaling laws ruling the phenomenon is also presented.

  20. Bright betatronlike x rays from radiation pressure acceleration of a mass-limited foil target.

    Science.gov (United States)

    Yu, Tong-Pu; Pukhov, Alexander; Sheng, Zheng-Ming; Liu, Feng; Shvets, Gennady

    2013-01-25

    By using multidimensional particle-in-cell simulations, we study the electromagnetic emission from radiation pressure acceleration of ultrathin mass-limited foils. When a circularly polarized laser pulse irradiates the foil, the laser radiation pressure pushes the foil forward as a whole. The outer wings of the pulse continue to propagate and act as a natural undulator. Electrons move together with ions longitudinally but oscillate around the latter transversely, forming a self-organized helical electron bunch. When the electron oscillation frequency coincides with the laser frequency as witnessed by the electron, betatronlike resonance occurs. The emitted x rays by the resonant electrons have high brightness, short durations, and broad band ranges which may have diverse applications.

  1. 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

  2. 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...

  3. Experiment of X-ray Generations Using Laser-Compton Scattering at LINAC of SINAP

    Institute of Scientific and Technical Information of China (English)

    PAN Qiang-yan; XU Wang; LUO Wen; FAN Gong-tao; Yang Li-feng; Fan Guang-wei; LI Yong-jiang; XU Ben-ji; SHI Xiang-chun; LIN Guo-qiang; YAN Zhe; XU Yi; CHEN Jing-gen; GUO Wei; WANG Hong-wei; WANG Cheng-bin; XU Jia-qiang; Ma Yu-gang; CAI Xiang-zhou; ZHAO Ming-hua; SHEN Wen-qing

    2009-01-01

    Laser Compton scattering(LCS) can generate X-rays or y-rays with high brightness and easy controlled polarization by applying high-peak-power laser pulses to relativistic electron bunches.One of the most promising approaches to short pulsed X-ray sources is the laser synchrotron source.It is based on LCS between picoseconds relativistic electron bunches and picoseconds laser pulses.A project of Shanghai laser electron gamma source with LCS method has been proposed on Shanghai synchrotron radiation facility.Before that,a prototype has been developed in the beamline of the linear accelerator at the Shanghai Institute of Applied Physics,Chinese Academy of Sciences.The LCS experiment was carried out by using the 107 MeV,5 Hz,1 ns,0.1 nC electron bunches from the linear accelerator and the 18 ns,10 MW peak power,Nd:YAG laser pulses.In this communication,we describe the details and report the first results of this experiment.

  4. Nonrelativistic quantum X-ray physics

    CERN Document Server

    Hau-Riege, Stefan P

    2015-01-01

    Providing a solid theoretical background in photon-matter interaction, Nonrelativistic Quantum X-Ray Physics enables readers to understand experiments performed at XFEL-facilities and x-ray synchrotrons. As a result, after reading this book, scientists and students will be able to outline and perform calculations of some important x-ray-matter interaction processes. Key features of the contents are that the scope reaches beyond the dipole approximation when necessary and that it includes short-pulse interactions. To aid the reader in this transition, some relevant examples are discussed in detail, while non-relativistic quantum electrodynamics help readers to obtain an in-depth understanding of the formalisms and processes. The text presupposes a basic (undergraduate-level) understanding of mechanics, electrodynamics, and quantum mechanics. However, more specialized concepts in these fields are introduced and the reader is directed to appropriate references. While primarily benefiting users of x-ray light-sou...

  5. 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

  6. 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.

  7. 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 ...

  8. Single Particle X-ray Diffractive Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Bogan, M J; Benner, W H; Boutet, S; Rohner, U; Frank, M; Seibert, M; Maia, F; Barty, A; Bajt, S; Riot, V; Woods, B; Marchesini, S; Hau-Riege, S P; Svenda, M; Marklund, E; Spiller, E; Hajdu, J; Chapman, H N

    2007-10-01

    In nanotechnology, strategies for the creation and manipulation of nanoparticles in the gas phase are critically important for surface modification and substrate-free characterization. Recent coherent diffractive imaging with intense femtosecond X-ray pulses has verified the capability of single-shot imaging of nanoscale objects at sub-optical resolutions beyond the radiation-induced damage threshold. By intercepting electrospray-generated particles with a single 15 femtosecond soft-X-ray pulse, we demonstrate diffractive imaging of a nanoscale specimen in free flight for the first time, an important step toward imaging uncrystallized biomolecules.

  9. 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.

  10. Recent trends of projection X-ray microscopy in Japan

    Energy Technology Data Exchange (ETDEWEB)

    Yada, K. [Tohken CO., LTD. 2-27-7 Tamagawa Chofu, Tokyo 182-0025 (Japan)], E-mail: kyada@tohken.co.jp

    2009-08-15

    Recent activities of projection X-ray microscopy in Japan are reviewed. 1) By employing high brightness Schottky electron gun, resolution of 0.1 {mu}m is realized by Tohken CO. group and some application examples are shown. 2) Deblurring of Fresnel diffracted image formed by synchrotron orbital radiation (SOR) X-rays is successfully tried by Chiba University group. Remarkable Fresnel fringes appearing at HeLa cell are mostly reconstructed by an iteration method. 3) Element analysis is carried out by Meiji University group utilizing absorption-edge characteristics between two kinds of X-ray targets without X-ray spectrometer. Actually, Cu and Ni targets are used with an inter-changeable system for elemental analysis of Fe{sub 2}O{sub 3} particles and iron component in a mosquito larva.

  11. Intrinsic beam emittance of laser-accelerated electrons measured by x-ray spectroscopic imaging.

    Science.gov (United States)

    Golovin, G; Banerjee, S; Liu, C; Chen, S; Zhang, J; Zhao, B; Zhang, P; Veale, M; Wilson, M; Seller, P; Umstadter, D

    2016-04-19

    The recent combination of ultra-intense lasers and laser-accelerated electron beams is enabling the development of a new generation of compact x-ray light sources, the coherence of which depends directly on electron beam emittance. Although the emittance of accelerated electron beams can be low, it can grow due to the effects of space charge during free-space propagation. Direct experimental measurement of this important property is complicated by micron-scale beam sizes, and the presence of intense fields at the location where space charge acts. Reported here is a novel, non-destructive, single-shot method that overcame this problem. It employed an intense laser probe pulse, and spectroscopic imaging of the inverse-Compton scattered x-rays, allowing measurement of an ultra-low value for the normalized transverse emittance, 0.15 (±0.06) π mm mrad, as well as study of its subsequent growth upon exiting the accelerator. The technique and results are critical for designing multi-stage laser-wakefield accelerators, and generating high-brightness, spatially coherent x-rays.

  12. 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 ...

  13. 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

  14. The vacuum system of the European X-ray free electron laser XFEL

    Energy Technology Data Exchange (ETDEWEB)

    Zapfe, K; Boehnert, M; Hensler, O; Hoppe, D; Mildner, N; Nagorny, B; Rehlich, K; Remde, H; Wagner, A; Wohlenberg, T; Wojtkiewicz, J [Deutsches Elektronen Synchrotron DESY, Notkestrasse 85, D-22607 Hamburg (Germany)], E-mail: kirsten.zapfe@desy.de

    2008-03-01

    The European X-ray Free Electron Laser XFEL, a new international research facility, will be built at DESY/Hamburg. The XFEL will generate extremely brilliant and ultra short pulses of spatially coherent X-rays with tuneable wavelengths down to 0.1 nm, and exploit them for revolutionary scientific experiments at various disciplines. The basic process adopted to produce the X-ray pulses is SASE (Self-Amplified Spontaneous Emission). Therefore electron bunches are produced in a high-brightness gun, brought to high energy of about 20 GeV through a superconducting linear accelerator, and transported to up to 250 m long undulators, where the X-rays are generated. The beam vacuum system of the accelerator contains sections operated at room temperature as well as at 2 K in the areas of the superconducting accelerating structures, thus requiring an insulating vacuum system. In addition to standard UHV requirements, the vacuum system for this facility needs to preserve the cleanliness of the superconducting cavity surfaces. Therefore the preparation of all vacuum components for the 1.6 km long main linac includes cleaning of the components in a clean room to remove particles, installation into the accelerator in local clean rooms, and special procedures for pump down and venting. Further challenges are the undulator vacuum chambers filling more than 700 m, where a high surface quality with respect to surface roughness and thickness of oxide layers is mandatory to reduce wake field effects, and the vacuum systems for the various beam dumps, where exit windows acting as vacuum barriers of sufficient reliability need to be developed. In addition, a large amount of about 1.7 km of transport beam lines is required. The layout of the various vacuum sections as well as experience with prototype components will be described.

  15. 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.

  16. 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.

  17. X-ray scattering from dense plasmas

    Energy Technology Data Exchange (ETDEWEB)

    McSherry, D.J

    2000-09-01

    Dense plasmas were studied by probing them with kilovolt x-rays and measuring those scattered at various angles. The Laser-Produced x-ray source emitted Ti He alpha 4.75 keV x-rays. Two different plasma types were explored. The first was created by laser driven shocks on either side of a sample foil consisting of 2 micron Al layer, sandwiched between two 1 micron CH layers. We have observed a peak in the x-ray scattering cross section, indicating diffraction from the plasma. However, the experimentally inferred plasma density, broadly speaking, did not always agree with the hydrodynamic simulation MEDX (A modified version of MEDUSA). The second plasma type that we studied was created by soft x-ray heating on either side of a sample foil, this time consisting of 1 micron layer of Al, sandwiched between two 0.2 micron CH layers. Two foil targets, each consisting of a 0.1 micron thick Au foil mounted on 1 micron of CH, where placed 4 mm from the sample foil. The soft x-rays where produced by laser irradiating these two foil targets. We found that, 0.5 ns after the peak of the laser heating pulses, the measured cross sections more closely matched those simulated using the Thomas Fermi model than the Inferno model. Later in time, at 2 ns, the plasma is approaching a weakly coupled state. This is the first time x-ray scattering cross sections have been measured from dense plasmas generated by radiatively heating both sides of the sample. Moreover, these are absolute values typically within a factor of two of expectation for early x-ray probe times. (author)

  18. X-ray scattering from dense plasmas

    Science.gov (United States)

    McSherry, Declan Joseph

    Dense plasmas were studied by probing them with kilovolt x-rays and measuring those scattered at various angles. The laser produced x-ray source emitted Ti He alpha 4.75 keV x-rays. Two different plasma types were explored. The first was created by laser driven shocks on either side of a sample foil consisting of 2 micron thickness of Al, sandwiched between two 1 micron CH layers. We have observed a peak in the x-ray scattering cross section, indicating diffraction from the plasma. However, the experimentally inferred plasma density, did not always agree broadly with the hydrodynamic simulation MEDX (A modified version of MEDUSA). The second plasma type that we studied was created by soft x-ray heating on either side of a sample foil, this time consisting of 1 micron thickness of Al, sandwiched between two 0.2 micron CH layers. Two foil targets, each consisting of a 0.1 micron thick Au foil mounted on 1 micron of CH, were placed 4 mm from the sample foil. The soft x-rays were produced by laser irradiating these two foil targets. We found that, 0.5 ns after the peak of the laser heating pulses, that the measured cross sections more closely matched those simulated using the Thomas Fermi model than the Inferno model. Later in time, at 2 ns, the plasma is approaching a weakly coupled state. This is the first time x-ray scattering cross sections have been measured from dense plasmas generated by radiatively heating both sides of the sample. Moreover, these are absolute values typically within a factor of two of expectation for early x-ray probe times.

  19. 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.

  20. Ultrafast X-Ray Coherent Control

    Energy Technology Data Exchange (ETDEWEB)

    Reis, David

    2009-05-01

    This main purpose of this grant was to develop the nascent eld of ultrafast x-ray science using accelerator-based sources, and originally developed from an idea that a laser could modulate the di racting properties of a x-ray di racting crystal on a fast enough time scale to switch out in time a shorter slice from the already short x-ray pulses from a synchrotron. The research was carried out primarily at the Advanced Photon Source (APS) sector 7 at Argonne National Laboratory and the Sub-Picosecond Pulse Source (SPPS) at SLAC; in anticipation of the Linac Coherent Light Source (LCLS) x-ray free electron laser that became operational in 2009 at SLAC (all National User Facilities operated by BES). The research centered on the generation, control and measurement of atomic-scale dynamics in atomic, molecular optical and condensed matter systems with temporal and spatial resolution . It helped develop the ultrafast physics, techniques and scienti c case for using the unprecedented characteristics of the LCLS. The project has been very successful with results have been disseminated widely and in top journals, have been well cited in the eld, and have laid the foundation for many experiments being performed on the LCLS, the world's rst hard x-ray free electron laser.

  1. 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.

  2. 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.

  3. Particle Formation from Pulsed Laser Irradiation of SootAggregates studied with scanning mobility particle sizer, transmissionelectron microscope and near-edge x-ray absorption fine structure.

    Energy Technology Data Exchange (ETDEWEB)

    Michelsen, Hope A.; Tivanski, Alexei V.; Gilles, Mary K.; vanPoppel, Laura H.; Dansson, Mark A.; Buseck, Peter R.; Buseck, Peter R.

    2007-02-20

    We investigated the physical and chemical changes induced in soot aggregates exposed to laser radiation using a scanning mobility particle sizer, a transmission electron microscope, and a scanning transmission x-ray microscope to perform near-edge x-ray absorption fine structure spectroscopy. Laser-induced nanoparticle production was observed at fluences above 0.12 J/cm(2) at 532 nm and 0.22 J/cm(2) at 1064 nm. Our results indicate that new particle formation proceeds via (1) vaporization of small carbon clusters by thermal or photolytic mechanisms, followed by homogeneous nucleation, (2) heterogeneous nucleation of vaporized carbon clusters onto material ablated from primary particles, or (3) both processes.

  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. 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.

  1. 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 ...

  2. 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 ...

  3. 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 ...

  4. 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 ...

  5. 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 ...

  6. 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 ...

  7. 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 ...

  8. 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...

  9. 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.

  10. Calculation of x-ray scattering patterns from nanocrystals at high x-ray intensity

    CERN Document Server

    Abdullah, Malik Muhammad; Son, Sang-Kil; Santra, Robin

    2016-01-01

    We present a generalized method to describe the x-ray scattering intensity of the Bragg spots in a diffraction pattern from nanocrystals exposed to intense x-ray pulses. Our method involves the subdivision of a crystal into smaller units. In order to calculate the dynamics within every unit we employ a Monte-Carlo (MC)-molecular dynamics (MD)-ab-initio hybrid framework using real space periodic boundary conditions. By combining all the units we simulate the diffraction pattern of a crystal larger than the transverse x-ray beam profile, a situation commonly encountered in femtosecond nanocrystallography experiments with focused x-ray free-electron laser radiation. Radiation damage is not spatially uniform and depends on the fluence associated with each specific region inside the crystal. To investigate the effects of uniform and non-uniform fluence distribution we have used two different spatial beam profiles, gaussian and flattop.

  11. JEM-X observations of the Be/X-ray binary EXO 2030+375

    DEFF Research Database (Denmark)

    Nunez, S.M.; Reig, P.; Blay, P.

    2003-01-01

    We have used data from the Joint European Monitor (JEM-X) to perform an X-ray spectral and timing analysis of the 42-s transient pulsar EXO 2030+375 during an X-ray outburst. X-ray pulsations are clearly detected with an average pulse period of 41.66+/-0.05 s and an average pulse fraction of 60%....

  12. Filtered fluorescer x-ray detector

    Energy Technology Data Exchange (ETDEWEB)

    Bruns, H.C.; Emig, J.A.; Thoe, R.S.; Springer, P.T.; Hernandez, J.A.

    1995-04-01

    Recently, an instrument capable of measuring x-rays between 8 and 90 keV was conceived to help understand conditions pertaining to pulsed power research. This resulted in the development of a versatile device that would incrementally detect x-rays emitted at predetermined energy bands over this range. To accomplish this, an array of well characterized filter-fluorescer combinations were produced which would allow fluoresced x-rays to be observed by time resolved electro-optical devices. As many as sixteen channels could be utilized with each channel having a corresponding background channel. Upon completion of the device, a three week series of experiments was then successfully carried out.

  13. 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.

  14. 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.

  15. 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.)

  16. Nonlinear X-ray Compton Scattering

    CERN Document Server

    Fuchs, Matthias; Chen, Jian; Ghimire, Shambhu; Shwartz, Sharon; Kozina, Michael; Jiang, Mason; Henighan, Thomas; Bray, Crystal; Ndabashimiye, Georges; Bucksbaum, P H; Feng, Yiping; Herrmann, Sven; Carini, Gabriella; Pines, Jack; Hart, Philip; Kenney, Christopher; Guillet, Serge; Boutet, Sebastien; Williams, Garth; Messerschmidt, Marc; Seibert, Marvin; Moeller, Stefan; Hastings, Jerome B; Reis, David A

    2015-01-01

    X-ray scattering is a weak linear probe of matter. It is primarily sensitive to the position of electrons and their momentum distribution. Elastic X-ray scattering forms the basis of atomic structural determination while inelastic Compton scattering is often used as a spectroscopic probe of both single-particle excitations and collective modes. X-ray free-electron lasers (XFELs) are unique tools for studying matter on its natural time and length scales due to their bright and coherent ultrashort pulses. However, in the focus of an XFEL the assumption of a weak linear probe breaks down, and nonlinear light-matter interactions can become ubiquitous. The field can be sufficiently high that even non-resonant multiphoton interactions at hard X-rays wavelengths become relevant. Here we report the observation of one of the most fundamental nonlinear X-ray-matter interactions, the simultaneous Compton scattering of two identical photons producing a single photon at nearly twice the photon energy. We measure scattered...

  17. 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.

  18. Transient electronic structure of the photoinduced phase of Pr0.7Ca0.3MnO3 probed with soft x-ray pulses

    Energy Technology Data Exchange (ETDEWEB)

    Rini, M.; Zhu, Y.; Wall, S.; Tobey, R. I.; Ehrke, H.; Garl, T.; Freeland, J. W.; Tomioka, Y.; Tokura, Y.; Cavalleri, A.; Schoenlein, R. W.

    2009-04-01

    We use time-resolved x-ray absorption near-edge structure spectroscopy to investigate the electronic dynamics associated with the photoinduced insulator-to-metal phase transition in the colossal magnetoresistive manganite Pr{sub 0.7}Ca{sub 0.3}MnO{sub 3}. Absorption changes at the O K and Mn L edges directly monitor the evolution of the density of unoccupied states in the transient photoinduced phase. We show that the electronic structure of the photoinduced phase is remarkably similar to that of the ferromagnetic metallic phase reached in related manganites upon cooling below the Curie temperature.

  19. Transient Lattice Response to the Interaction between Pulse-Laser and Semiconductors Probed by Time-Resolved X-Ray Diffraction

    Science.gov (United States)

    Kishimura, Hiroaki; Kawano, Hidetaka; Hironaka, Yoichiro; Nakamura, Kazutaka G.; Kondo, Ken-ichi

    2004-07-01

    Time-resolved X-ray diffraction has been performed on laser irradiated Si and Ge crystals. In the case of Si, the lattice expansion due to laser heating is observed. On the other hand, the compression wave is propagated into a Ge crystal. The maximum compression of Ge is about 4 %, which is larger than the Hugoniot elastic limit (HEL). The results suggest that Ge is not compressed hydrostatically, but compressed uniaxially at 7.5 GPa in a picosecond time scale. The strain profiles inside the crystals are obtained as the calculated rocking curves represent well the experiment.

  20. Imaging X-ray Thomson Scattering Spectrometer Design and Demonstration

    Energy Technology Data Exchange (ETDEWEB)

    Gamboa, E.J. [University of Michigan; Huntington, C.M. [University of Michigan; Trantham, M.R. [University of Michigan; Keiter, P.A [University of Michigan; Drake, R.P. [University of Michigan; Montgomery, David [Los Alamos National Laboratory; Benage, John F. [Los Alamos National Laboratory; Letzring, Samuel A. [Los Alamos National Laboratory

    2012-05-04

    In many laboratory astrophysics experiments, intense laser irradiation creates novel material conditions with large, one-dimensional gradients in the temperature, density, and ionization state. X-ray Thomson scattering is a powerful technique for measuring these plasma parameters. However, the scattered signal has previously been measured with little or no spatial resolution, which limits the ability to diagnose inhomogeneous plasmas. We report on the development of a new imaging x-ray Thomson spectrometer (IXTS) for the Omega laser facility. The diffraction of x-rays from a toroidally-curved crystal creates high-resolution images that are spatially resolved along a one-dimensional profile while spectrally dispersing the radiation. This focusing geometry allows for high brightness while localizing noise sources and improving the linearity of the dispersion. Preliminary results are presented from a scattering experiment that used the IXTS to measure the temperature profile of a shocked carbon foam.

  1. 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.

  2. Comparison of hard x-ray production from various targets in air using a short pulse kHz laser with photon production from a high power multifilament laser beam from the same targets in air

    CERN Document Server

    Ledingham, K W D; McCanny, T; Melone, J J; Spohr, K; Schramm, U; Kraft, S D; Wagner, A; Jochmann, A

    2011-01-01

    Over the last few years there has been much interest in the production of hard X-rays from various targets using a kHz short pulse laser at intensities above 1014Wcm-2 (A). Most of these studies have been carried out in vacuum and very many fewer studies have been carried out in air. Recently this lack has been partially addressed with the development of femtosecond laser micromachining. Another similar although apparently unconnected field (B) deals with the channelling of high power laser beam in filaments after passage through long distances in air. This has been largely driven by the construction of a mobile terawatt laser beam (Teramobile) for atmospheric studies. The laser beams in these two cases (A and B) have very different pulse energies (mJ against J) although the filaments in (B) have similar energies to (A) and are clamped at intensities less than 1014 Wcm-2. This paper has been written to compare the production of hard X-rays in these two cases. The conclusion is interesting that a focused sub T...

  3. Optoelectronic Picosecond Detection of Synchrotron X-rays

    Energy Technology Data Exchange (ETDEWEB)

    Durbin, Stephen M. [Purdue Univ., West Lafayette, IN (United States)

    2017-08-04

    The goal of this research program was to develop a detector that would measure x-ray time profiles with picosecond resolution. This was specifically aimed for use at x-ray synchrotrons, where x-ray pulse profiles have Gaussian time spreads of 50-100 ps (FWHM), so the successful development of such a detector with picosecond resolution would permit x-ray synchrotron studies to break through the pulse width barrier. That is, synchrotron time-resolved studies are currently limited to pump-probe studies that cannot reveal dynamics faster than ~50 ps, whereas the proposed detector would push this into the physically important 1 ps domain. The results of this research effort, described in detail below, are twofold: 1) the original plan to rely on converting electronic signals from a semiconductor sensor into an optical signal proved to be insufficient for generating signals with the necessary time resolution and sensitivity to be widely applicable; and 2) an all-optical method was discovered whereby the x-rays are directly absorbed in an optoelectronic material, lithium tantalate, which can then be probed by laser pulses with the desired picosecond sensitivity for detection of synchrotron x-rays. This research program has also produced new fundamental understanding of the interaction of x-rays and optical lasers in materials that has now created a viable path for true picosecond detection of synchrotron x-rays.

  4. Incoherent x-ray scattering in single molecule imaging

    CERN Document Server

    Slowik, Jan Malte; Dixit, Gopal; Jurek, Zoltan; Santra, Robin

    2014-01-01

    Imaging of the structure of single proteins or other biomolecules with atomic resolution would be enormously beneficial to structural biology. X-ray free-electron lasers generate highly intense and ultrashort x-ray pulses, providing a route towards imaging of single molecules with atomic resolution. The information on molecular structure is encoded in the coherent x-ray scattering signal. In contrast to crystallography there are no Bragg reflections in single molecule imaging, which means the coherent scattering is not enhanced. Consequently, a background signal from incoherent scattering deteriorates the quality of the coherent scattering signal. This background signal cannot be easily eliminated because the spectrum of incoherently scattered photons cannot be resolved by usual scattering detectors. We present an ab initio study of incoherent x-ray scattering from individual carbon atoms, including the electronic radiation damage caused by a highly intense x-ray pulse. We find that the coherent scattering pa...

  5. High-harmonic generation: Ultrafast lasers yield X-rays

    NARCIS (Netherlands)

    McKinnie, Iain; Kapteyn, Henry

    2010-01-01

    Table-top sources that generate both extreme ultraviolet light and soft X-rays through high-harmonic generation of ultrafast infrared laser pulses look set to perform tasks previously accessible using only large-scale synchrotrons.

  6. 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…

  7. 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.

  8. 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...

  9. 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.

  10. 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.

  11. Studies of electron diffusion in photo-excited Ni using time-resolved X-ray diffraction

    Science.gov (United States)

    Persson, A. I. H.; Jarnac, A.; Wang, Xiaocui; Enquist, H.; Jurgilaitis, A.; Larsson, J.

    2016-11-01

    We show that the heat deposition profile in a laser-excited metal can be determined by time-resolved X-ray diffraction. In this study, we investigated the electron diffusion in a 150 nm thick nickel film deposited on an indium antimonide substrate. A strain wave that mimics the heat deposition profile is generated in the metal and propagates into the InSb, where it influences the temporal profile of X-rays diffracted from InSb. We found that the strain pulse significantly deviated from a simple exponential profile, and that the two-temperature model was needed to reproduce the measured heat deposition profile. Experimental results were compared to simulations based on the two-temperature model carried out using commercial finite-element software packages and on-line dynamical diffraction tools. To reproduce the experimental data, the electron-phonon coupling factor was lowered compared to previously measured values. The experiment was carried out at a third-generation synchrotron radiation source using a high-brightness beam and an ultrafast X-ray streak camera with a temporal resolution of 3 ps.

  12. 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.

  13. Characterization of new hard X-ray Cataclysmic Variables

    CERN Document Server

    Bernardini, F; Falanga, M; Mukai, K; Matt, G; Bonnet-Bidaud, J -M; Masetti, N; Mouchet, M

    2012-01-01

    We aim at characterizing a sample of 9 new hard X-ray selected Cataclysmic Variable (CVs), to unambiguously identify them as magnetic systems of the Intermediate Polar (IP) type. We performed 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 X-ray spectra were fitted using composite models consisting of different absorbing columns and emission components. 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 IGR J08390-4833, IGR J18308-1232, and IGR J18173-2509. All X-ray spectra are multi-temperature. V2069 Cyg and RX J0636+3535 posses a soft X-ray optica...

  14. High-brightness rf linear accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Jameson, R.A.

    1986-01-01

    The issue of high brightness and its ramifications in linacs driven by radio-frequency fields is discussed. A history of the RF linacs is reviewed briefly. Some current applications are then examined that are driving progress in RF linacs. The physics affecting the brightness of RF linacs is then discussed, followed by the economic feasibility of higher brightness machines. (LEW)

  15. High-brightness rf linear accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Jameson, R.A.

    1986-01-01

    The issue of high brightness and its ramifications in linacs driven by radio-frequency fields is discussed. A history of the RF linacs is reviewed briefly. Some current applications are then examined that are driving progress in RF linacs. The physics affecting the brightness of RF linacs is then discussed, followed by the economic feasibility of higher brightness machines. (LEW)

  16. X-ray generation using carbon nanotubes

    Science.gov (United States)

    Parmee, Richard J.; Collins, Clare M.; Milne, William I.; Cole, Matthew T.

    2015-01-01

    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 demanding medical and inspection techniques, including computed tomography and tomosynthesis, security inspection, high throughput manufacturing and radiotherapy, has resulted in a considerable level of interest in the development of new fabrication methods. The use of conventional thermionic sources is limited by their slow temporal response and large physical size. In response, field electron emission has emerged as a promising alternative means of deriving a highly controllable electron beam of a well-defined distribution. When coupled to the burgeoning field of nanomaterials, and in particular, carbon nanotubes, such systems present a unique technological opportunity. This review provides a summary of the current state-of-the-art in carbon nanotube-based field emission X-ray sources. We detail the various fabrication techniques and functional advantages associated with their use, including the ability to produce ever smaller electron beam assembles, shaped cathodes, enhanced temporal stability and emergent fast-switching pulsed sources. We conclude with an overview of some of the commercial progress made towards the realisation of an innovative and disruptive technology.

  17. X-ray Pulsation Searches with NICER

    Science.gov (United States)

    Ray, Paul S.; Arzoumanian, Zaven

    2016-04-01

    The Neutron Star Interior Composition Explorer (NICER) is an X-ray telescope with capabilities optimized for the study of the structure, dynamics, and energetics of neutron stars through high-precision timing of rotation- and accretion-powered pulsars in the 0.2-12 keV band. It has large collecting area (twice that of the XMM-Newton EPIC-pn camera), CCD-quality spectral resolution, and high-precision photon time tagging referenced to UTC through an onboard GPS receiver. NICER will begin its 18-month prime mission as an attached payload on the International Space Station around the end of 2016. I will describe the science planning for the pulsation search science working group, which is charged with searching for pulsations and studying flux modulation properties of pulsars and other neutron stars. A primary goal of our observations is to detect pulsations from new millisecond pulsars that will contribute to NICER’s studies of the neutron star equation of state through pulse profile modeling. Beyond that, our working group will search for pulsations in a range of source categories, including LMXBs, new X-ray transients that might be accreting millisecond pulsars, X-ray counterparts to unassociated Fermi LAT sources, gamma-ray binaries, isolated neutron stars, and ultra-luminous X-ray sources. I will survey our science plans and give an overview of our planned observations during NICER’s prime mission.

  18. X-Ray Emission from Rotation-Powered Pulsars

    Institute of Scientific and Technical Information of China (English)

    LIN Gui-Fang; ZHANG Li

    2005-01-01

    @@ We study the properties of pulsed component of hard (2-10keV) x-ray emission from pulsars based on the new version of outer gap model we proposed previously [Astrophys.J.604 (2004) 317].On the frame of this outer gap model, we derive an expression of non-thermal pulsed x-ray luminosity of rotation-powered pulsars, and then apply it to the pulsars whose pulsed x-rays are detected by ASCA.Using the Kolmogorov-Smirnov test,we determine the model parameter.The present results indicate LX ∝ L1.15sd for these x-ray pulsars, which is consistent with the observed data.

  19. Calculation of x-ray scattering patterns from nanocrystals at high x-ray intensity

    OpenAIRE

    Malik Muhammad Abdullah; Zoltan Jurek; Sang-Kil Son; Robin Santra

    2016-01-01

    We present a generalized method to describe the x-ray scattering intensity of the Bragg spots in a diffraction pattern from nanocrystals exposed to intense x-ray pulses. Our method involves the subdivision of a crystal into smaller units. In order to calculate the dynamics within every unit we employ a Monte-Carlo (MC)-molecular dynamics (MD)-ab-initio hybrid framework using real space periodic boundary conditions. By combining all the units we simulate the diffraction pattern of a crystal la...

  20. 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 ...

  1. 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 ...

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. Quantum effets in nonresonant X-ray scattering

    Energy Technology Data Exchange (ETDEWEB)

    Slowik, Jan Malte

    2015-11-15

    Due to their versatile properties, X rays are a unique tool to investigate the structure and dynamics of matter. X-ray scattering is the fundamental principle of many imaging techniques. Examples are X-ray crystallography, which recently celebrated one hundred years and is currently the leading method in structure determination of proteins, as well as X-ray phase contrast imaging (PCI), which is an imaging technique with countless applications in biology, medicine, etc. The technological development of X-ray free electron lasers (XFEL) has brought X-ray imaging at the edge of a new scientific revolution. XFELs offer ultrashort X-ray pulses with unprecedented high X-ray fluence and excellent spatial coherence properties. These properties make them an outstanding radiation source for X-ray scattering experiments, providing ultrafast temporal resolution as well as atomic spatial resolution. However, the radiation-matter interaction in XFEL experiments also advances into a novel regime. This demands a sound theoretical fundament to describe and explore the new experimental possibilities. This dissertation is dedicated to the theoretical study of nonresonant X-ray scattering. As the first topic, I consider the near-field imaging by propagation based X-ray phase contrast imaging (PCI). I devise a novel theory of PCI, in which radiation and matter are quantized. Remarkably, the crucial interference term automatically excludes contributions from inelastic scattering. This explains the success of the classical description thus far. The second topic of the thesis is the X-ray imaging of coherent electronic motion, where quantum effects become particularly apparent. The electron density of coherent electronic wave packets - important in charge transfer and bond breaking - varies in time, typically on femto- or attosecond time scales. In the near future, XFELs are envisaged to provide attosecond X-ray pulses, opening the possibility for time-resolved ultrafast X-ray scattering

  7. Investigation of stability and x-ray spectrum in gas-puff z-pinch plasmas diriven by inductive energy storage pulsed power generator with a plasma opening switch

    Energy Technology Data Exchange (ETDEWEB)

    Murayama, K.; Fukudome, I. [Yatsushiro National College of Technology, Dept. of Mechanical and Electrical Engineering, Yatsushiro, Kumamoto (Japan); Teramoto, Y.; Katsuki, S.; Akiyama, H. [Kumamoto Univ., Dept. of Electrical and Computer Engineering, Kumamoto (Japan)

    2002-06-01

    Gas-puff z-pinch plasmas are driven by an inductive voltage adder - inductive energy storage pulsed power generator ''ASO-X''. ASO-X has the performance of the maximum output voltage and current are 180 kV and 400 kA respectively and can provide a fast rise time current with operating POS. The stability of the plasma column, spectrum radiated from z-pinch plasmas and the spatial distribution of hot spots are investigated in the case with and without operating POS. By driving ASO-X with operating POS the kink instability is restrained and the stability of plasma column is improved about three times in regard to the average dispersion. Furthermore the duration of soft x-ray radiation is increased and the spatial distribution of hot spots is 50% improved with regard to kurtosis of the intensity profile of pinhole photographs compared to those without operating POS. (author)

  8. 57Fe-ion implantation in pulse laser deposited La0.75Ca0.25MnO3 films: Conversion electron Mössbauer spectroscopy and X-ray diffraction studies

    Indian Academy of Sciences (India)

    U D Lanke; J Prabhjyot Pal

    2000-02-01

    Oriented La0.75Ca0.25MnO3 (LCMO) films have been deposited by pulsed laser deposition (PLD) method on (100) LaAlO3 substrates. Ion-beam technique is used to introduce a very low concentration of 57Fe+ in LCMO film. The deposited films were subjected to 100 keV 57Fe+ implantation with different fluences at room temperature. The main motivation of this work was to study the influence of implantation on the transport mechanism in materials exhibiting colossal magnetoresistance (CMR) property. It is observed that Fe implantation drastically affects the structural and magneto-transport properties. The samples were characterized using the X-ray diffraction (XRD) technique, conversion electron Mössbauer spectroscopy (CEMS) and resistance temperature (–) measurements.

  9. 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.

  10. Coherent methods in X-ray scattering

    Energy Technology Data Exchange (ETDEWEB)

    Gorobtsov, Oleg

    2017-05-15

    X-ray radiation has been used to study structural properties of materials for more than a hundred years. Construction of extremely coherent and bright X-ray radiation sources such as free electron lasers (FELs) and latest generationstorage rings led to rapid development of experimental methods relying on high radiation coherence. These methods allow to perform revolutionary studies in a wide range of fields from solid state physics to biology. In this thesis I focus on several important problems connected with the coherent methods. The first part considers applications of dynamical diffraction theory on crystals to studies with coherent X-ray radiation. It presents the design of a high-resolution spectrometer for free electron lasers that should allow to resolve spectral structure of individual FEL pulses. The spectrometer is based on the principle of dynamical diffraction focusing. The knowledge of individual FEL pulse spectra is necessary for understanding FEL longitudinal coherence. In the same part I present quasi-kinematical approximation to dynamical theory which allows to treat analytically phase effects observed in X-ray coherent imaging on nanocrystals. These effects may play a big role when methods such as ptychography are used to study crystalline samples. The second part deals with measurements of FEL coherence properties using intensity - intensity interferometry. Results of several experiments performed at FELs FLASH and LCLS are revealed in this section. I have developed models and theories to explain the behavior observed in experiments on FLASH. These models allowed to extract information about external positional jitter of FEL pulses and secondary beams present in FEL radiation. In the LCLS experiment the Hanbury Brown and Twiss type interferometry was performed on Bragg peaks from colloidal crystal. This did not require additional measurements without the sample and information was extracted directly from diffraction patterns. Therefore intensity

  11. 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.

  12. Small-animal tomography with a liquid-metal-jet x-ray source

    Science.gov (United States)

    Larsson, D. H.; Lundström, U.; Westermark, U.; Takman, P. A. C.; Burvall, A.; Arsenian Henriksson, M.; Hertz, H. M.

    2012-03-01

    X-ray tomography of small animals is an important tool for medical research. For high-resolution x-ray imaging of few-cm-thick samples such as, e.g., mice, high-brightness x-ray sources with energies in the few-10-keV range are required. In this paper we perform the first small-animal imaging and tomography experiments using liquid-metal-jet-anode x-ray sources. This type of source shows promise to increase the brightness of microfocus x-ray systems, but present sources are typically optimized for an energy of 9 keV. Here we describe the details of a high-brightness 24-keV electron-impact laboratory microfocus x-ray source based on continuous operation of a heated liquid-In/Ga-jet anode. The source normally operates with 40 W of electron-beam power focused onto the metal jet, producing a 7×7 μm2 FWHM x-ray spot. The peak spectral brightness is 4 × 109 photons / ( s × mm2 × mrad2 × 0.1%BW) at the 24.2 keV In Kα line. We use the new In/Ga source and an existing Ga/In/Sn source for high-resolution imaging and tomography of mice.

  13. 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...

  14. Fiscal 1998 R and D report on femtosecond technology (power generation facility monitoring system using high- intensity X-ray pulse); 1998 nendo femuto byo technology no kenkyu kaihatsu (kokido X senb pulse riyo hatsuden shisetsu monitoring system no kenkyu kaihatsu) seika hokokusho

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-03-01

    This report reports the fiscal 1998 R and D result of Femtosecond Technology Research Association (FESTA) supported by NEDO. For creation of industrial basic technologies supporting the advanced information society in the 21st century, ultra-high speed electronics technology including new functions beyond the speed limit of conventional electronics technologies is indispensable. From such viewpoint, this R and D aims at establishment of the basic technology controlling conditions of beams and electrons in a femtosecond (10{sup -15}-10{sup -12} seconds) region. In development of the titled system, this R and D aims at generation of high-intensity X-ray pulse by interaction between femtosecond light pulse and high-density electron beam pulse, and development of measurement technology (non- stop inspection) of high-speed moving objects using such X- ray pulse. In fiscal 1998, this project succeeded in time stabilization of laser oscillators at a 100fs level and generation of low-emittance electron beam pulse through development of ultra-short pulse synchronization, laser stabilization and electron beam pulse generation technologies. (NEDO)

  15. Attosecond Hard X-ray Free Electron Laser

    Directory of Open Access Journals (Sweden)

    Sandeep Kumar

    2013-03-01

    Full Text Available In this paper, several schemes of soft X-ray and hard X-ray free electron lasers (XFEL and their progress are reviewed. Self-amplified spontaneous emission (SASE schemes, the high gain harmonic generation (HGHG scheme and various enhancement schemes through seeding and beam manipulations are discussed, especially in view of the generation of attosecond X-ray pulses. Our recent work on the generation of attosecond hard X-ray pulses is also discussed. In our study, the enhanced SASE scheme is utilized, using electron beam parameters of an XFEL under construction at Pohang Accelerator Laboratory (PAL. Laser, chicane and electron beam parameters are optimized to generate an isolated attosecond hard X-ray pulse at 0.1 nm (12.4 keV. The simulations show that the manipulation of electron energy beam profile may lead to the generation of an isolated attosecond hard X-ray of 150 attosecond pulse at 0.1 nm.

  16. Observations and diagnostics in high brightness beams

    Energy Technology Data Exchange (ETDEWEB)

    Cianchi, A., E-mail: alessandro.cianchi@roma2.infn.it [University of Rome Tor Vergata and INFN-Roma Tor Vergata, Via della Ricerca Scientifica 1, 00133 Rome (Italy); Anania, M.P.; Bisesto, F.; Castellano, M.; Chiadroni, E.; Pompili, R.; Shpakov, V. [INFN-LNF, Via Enrico Fermi 40, 00044 Frascati (Italy)

    2016-09-01

    The brightness is a figure of merit largely used in the light sources, like FEL (Free Electron Lasers), but it is also fundamental in several other applications, as for instance Compton backscattering sources, beam driven plasma accelerators and THz sources. Advanced diagnostics are essential tools in the development of high brightness beams. 6D electron beam diagnostics will be reviewed with emphasis on emittance measurement.

  17. Recent X-Ray Laser Experiments on the COMET Facility

    Energy Technology Data Exchange (ETDEWEB)

    Dunn, J; Smith, R F; Nilsen, J; Hunter, J R; Barbee, T W; Shlyaptsev, V N; Filevich, J; Rocca, J J; Marconi, M C; Fiedorowicz, H; Bartnik, A

    2001-09-22

    The development of the transient collisional excitation x-ray laser scheme using tabletop laser systems with multiple pulse capability has progressed rapidly in the last three years. The high small-signal gain and strong x-ray output have been demonstrated for laser drive energies of typically less than 10 J. We report recent x-ray laser experiments on the Lawrence Livermore National Laboratory (LLNL) Compact Multipulse Terawatt (COMET) tabletop facility using this technique. In particular, the saturated output from the Ni-like Pd ion 4d - 4p x-ray laser at 146.8 {angstrom} has been well characterized and has potential towards a useable x-ray source in a number of applications. One important application of a short wavelength x-ray laser beam with picosecond pulse duration is the study of a high density laser-produced plasma. We report the implementation of a Mach-Zehnder type interferometer using diffraction grating optics as beam splitters designed for the Ni-like Pd laser and show results from probing a 600 ps heated plasma. In addition, gas puff targets are investigated as an x-ray laser gain medium and we report results of strong lasing on the n = 3 - 3 transitions of Ne-like Ar.

  18. Correlation between X-ray Lightcurve Shape and Radio Arrival Time in the Vela Pulsar

    CERN Document Server

    Lommen, A; Gwinn, C; Arzoumanian, Z; Harding, A; Strickman, M S; Dodson, R; McCulloch, P; Moffett, D

    2006-01-01

    We report the results of simultaneous observations of the Vela pulsar in X-rays and radio from the RXTE satellite and the Mount Pleasant Radio Observatory in Tasmania. We sought correlations between the Vela's X-ray emission and radio arrival times on a pulse by pulse basis. At a confidence level of 99.8% we have found significantly higher flux density in Vela's main X-ray peak during radio pulses that arrived early. This excess flux shifts to the 'trough' following the 2nd X-ray peak during radio pulses that arrive later. Our results suggest that the mechanism producing the radio pulses is intimately connected to the mechanism producing X-rays. Current models using resonant absorption of radio emission in the outer magnetosphere as a cause of the X-ray emission are explored as a possible explanation for the correlation.

  19. Gain spectrum in gated x-ray MCPs

    Energy Technology Data Exchange (ETDEWEB)

    Kyrala, George A [Los Alamos National Laboratory; Oertel, John A [Los Alamos National Laboratory; Archuleta, Thomas N [Los Alamos National Laboratory; Holder, Joe [LLNL

    2009-01-01

    The gain spectrum in a gated multichannel intensifier output depends on the gain and spatial averaging. The spectrum affects the minimum signal that can be detected as well as the signal to noise in the detected images. We will present data on the gain-spectrum for the GXD detector, a gated x-ray detector to be used at the National Ignition Facility. The data was recorded on a cooled CCD detector, with an x-ray gating time of approximately 75 ps, selected from a range of 0.2 and 1 ns electrical pulse width determined by pulse forming modules were also used. The detector was characterized at the TRIDENT laser facility, using a 2.4 ns long x-ray at 4.75 keV. The x-rays were generated by the interaction of the focused Trident laser beam with a Titanium target.

  20. 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.

  1. Applications of Indirect Imaging techniques in X-ray binaries

    CERN Document Server

    Harlaftis, E T

    2000-01-01

    A review is given on aspects of indirect imaging techniques in X-ray binaries which are used as diagnostics tools for probing the X-ray dominated accretion disc physics. These techniques utilize observed properties such as the emission line profile variability, the time delays between simultaneous optical/X-ray light curves curves, the light curves of eclipsing systems and the pulsed emission from the compact object in order to reconstruct the accretion disc's line emissivity (Doppler tomography), the irradiated disc and heated secondary (echo mapping), the outer disc structure (modified eclipse mapping) and the accreting regions onto the compact object, respectively.

  2. FERMI @ Elettra -- A Seeded Harmonic Cascade FEL for EUV and SoftX-rays

    Energy Technology Data Exchange (ETDEWEB)

    Bocchetta, C.; Bulfone, D.; Craievich, P.; Danailov, M.B.; D' Auria,G.; DeNinno, G.; Di Mitri, S.; Diviacco, B.; Ferianis, M.; Gomezel, A.; Iazzourene, F.; Karantzoulis, E.; Parmigiani, F.; Penco, G.; Trovo, M.; Corlett, J.; Fawley, W.; Lidia, S.; Penn, G.; Ratti, A.; Staples, J.; Wilcox, R.; Zholents, A.; Graves, W.; Ilday, F.O.; Kaertner,F.; Wang, D.; Zwart, T.; Cornacchia, M.; Emma, P.; Huang, Z.; Wu, J.

    2005-09-01

    We describe the machine layout and major performance parameters for the FERMI FEL project funded for construction at Sincrotrone Trieste, Italy, within the next five years. The project will be the first user facility based on seeded harmonic cascade FELs, providing controlled, high peak-power pulses. With a high-brightness rf photocathode gun, and using the existing 1.2 GeV S-band linac, the facility will provide tunable output over a range from {approx}100 nm to {approx}10nm, with pulse duration from 40 fs to {approx} 1 ps, peak power GW, and with fully variable output polarization. Initially, two FEL cascades are planned; a single-stage harmonic generation to operate >40 nm, and a two stage cascade operating from {approx}40 nm to {approx}10 nm or shorter wavelength. The output is spatially and temporally coherent, with peak power in the GW range. Lasers provide modulation to the electron beam, as well as driving the photocathode and other systems, and the facility will integrate laser systems with the accelerator infrastructure, including a state-of-the-art optical timing system providing synchronization of rf signals, lasers, and x-ray pulses. Major systems and overall facility layout are described, and key performance parameters summarized.

  3. FERMI@Elettra: A Seeded Harmonic Cascade FEL for EUV and Soft X-Rays

    Energy Technology Data Exchange (ETDEWEB)

    Bocchetta, C.J.; Bulfone, D.; Craievich, P.; Danailov, M.B.; D' Auria, G.; De Ninno, G.; Di Mitri, S.; Diviacco, B.; Ferianis, M.; Gomezel, A.; Iazzourene, F.; Karantzoulis, E.; Parmigiani, F.; Penco, G.; Trovo, M.; /Sincrotrone Trieste; Corlett, J.; Fawley, W.; Lidia, S.; Penn, G.; Ratti, A.; Staples, J.; /LBL, Berkeley /MIT /SLAC

    2005-12-14

    We describe the machine layout and major performance parameters for the FERMI FEL project funded for construction at Sincrotrone Trieste, Italy, within the next five years. The project will be the first user facility based on seeded harmonic cascade FEL's, providing controlled, high peak-power pulses. With a high-brightness rf photocathode gun, and using the existing 1.2 GeV S-band linac, the facility will provide tunable output over a range from {approx}100 nm to {approx}10 nm, with pulse duration from 40 fs to {approx} 1ps, peak power {approx}GW, and with fully variable output polarization. Initially, two FEL cascades are planned; a single-stage harmonic generation to operate > 40 nm, and a two-stage cascade operating from {approx}40 nm to {approx}10 nm or shorter wavelength. The output is spatially and temporally coherent, with peak power in the GW range. Lasers provide modulation to the electron beam, as well as driving the photocathode and other systems, and the facility will integrate laser systems with the accelerator infrastructure, including a state-of-the-art optical timing system providing synchronization of rf signals, lasers, and x-ray pulses. Major systems and overall facility layout are described, and key performance parameters summarized.

  4. 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 ...

  5. 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 ...

  6. Bone X-Ray (Radiography)

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    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 ...

  7. Bone X-Ray (Radiography)

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    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 ...

  8. Bone X-Ray (Radiography)

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    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 ...

  9. 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)

  10. Bone X-Ray (Radiography)

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    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 ...

  11. Bone X-Ray (Radiography)

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    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 ...

  12. 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...

  13. Bone X-Ray (Radiography)

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    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, ...

  14. Bone X-Ray (Radiography)

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    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 ...

  15. Bone X-Ray (Radiography)

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    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 ...

  16. Bone X-Ray (Radiography)

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    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, ...

  17. Bone X-Ray (Radiography)

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    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 ...

  18. Bone X-Ray (Radiography)

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    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 ...

  19. Bone X-Ray (Radiography)

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    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 ...

  20. Bone X-Ray (Radiography)

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    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 ...

  1. 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, ...

  2. Bone X-Ray (Radiography)

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    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 ...

  3. Bone X-Ray (Radiography)

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    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 ...

  4. Bone X-Ray (Radiography)

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    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 ...

  5. Bone X-Ray (Radiography)

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    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 ...

  6. Generation of soft x-ray radiation by laser irradiation of a gas puff xenon target

    Energy Technology Data Exchange (ETDEWEB)

    Fiedorowicz, H.; Bartnik, A.; Szczurek, M. [Military Univ. of Technology, Warsaw (Poland). Inst. of Optoelectronics] [and others

    1995-12-31

    Plasmas produced from laser-irradiated gas puff xenon targets, created by pulsed injection of xenon with high-pressure solenoid valve, offer the possibility of realizing a debrisless x-ray point source for the x-ray lithography applications. In this paper the authors present results of the experimental investigations on the x-ray generation from a gas puff xenon target irradiated with nanosecond high-power laser pulses produced using two different laser facilities: a Nd:glass laser operating at 1.06 {micro}m, which generated 10--15 J pulses in 1 ns FWHM, and Nd:glass slab laser, producing pulses of 10 ns duration with energy reaching 12 J for a 0.53 {micro}m wavelength or 20 J for 1.05 {micro}m. To study the x-ray emission different x-ray diagnostic methods have been used. X-ray spectra were registered using a flat CsAP crystal spectrograph with an x-ray film or a curved KAP crystal spectrograph with a convex curvature to an x-ray CCD readout detector. X-ray images have been taken using pinhole cameras with an x-ray film or a CCD array. X-ray yield was measured with the use of semiconductor detectors (silicon photodiodes or diamond photoconductors).

  7. 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.

  8. 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.

  9. 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)

  10. 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

  11. A complete library of X-ray pulsars in the Magellanic Clouds: A new resource for modeling the time evolution of luminosity and pulse profile

    Science.gov (United States)

    Yang, Jun; Laycock, Silas; Christodoulou, Dimitris; Fingerman, Samuel; Cappallo, Rigel; Zezas, Andreas; Antoniou, Vallia; Hong, Jaesub; Ho, Wynn; Coe, Malcolm; Klus, Helen

    2016-01-01

    We have collected and analyzed all XMM-Newton and Chandra (˜ 300) observations of the known pulsars in the Small & Large Magellanic Clouds (SMC, LMC). We aim to classify various pulsar properties with amplitude logLX = 33 ˜ 38 erg/s and incorporate the related parameters in theoretical models. With the high time-resolution data from the European Photon Imaging Camera (EPIC) and the latest calibration files and the Science Analysis System (SAS) software from High Energy Astrophysics Science Archive Research Center Software (HEASOFT), our pipeline generates a suite of useful products for each pulsar detection: point-source event lists, pulse profiles, periodograms, and spectra for the broad energy band, the soft band (0.2-2 keV), and the hard band (2-12 keV). Of 59 SMC pulsars in the EPIC field of view, we were able to measure 29 with pulse periods and power spectra. From XMM for example, for 16 of them, we find 12 are spinning up and 4 are spinning down. We also compare the observed pulse profiles to geometric models of the pulsars in order to constrain the magnetospheric parameters of each of these sources. Our motivation is to provide a library for time domain studies and profile modeling.

  12. 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)

  13. 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 ...

  14. Pulsed Laser Ablation-Induced Green Synthesis of TiO2 Nanoparticles and Application of Novel Small Angle X-Ray Scattering Technique for Nanoparticle Size and Size Distribution Analysis

    Science.gov (United States)

    Singh, Amandeep; Vihinen, Jorma; Frankberg, Erkka; Hyvärinen, Leo; Honkanen, Mari; Levänen, Erkki

    2016-10-01

    This paper aims to introduce small angle X-ray scattering (SAXS) as a promising technique for measuring size and size distribution of TiO2 nanoparticles. In this manuscript, pulsed laser ablation in liquids (PLAL) has been demonstrated as a quick and simple technique for synthesizing TiO2 nanoparticles directly into deionized water as a suspension from titanium targets. Spherical TiO2 nanoparticles with diameters in the range 4-35 nm were observed with transmission electron microscopy (TEM). X-ray diffraction (XRD) showed highly crystalline nanoparticles that comprised of two main photoactive phases of TiO2: anatase and rutile. However, presence of minor amounts of brookite was also reported. The traditional methods for nanoparticle size and size distribution analysis such as electron microscopy-based methods are time-consuming. In this study, we have proposed and validated SAXS as a promising method for characterization of laser-ablated TiO2 nanoparticles for their size and size distribution by comparing SAXS- and TEM-measured nanoparticle size and size distribution. SAXS- and TEM-measured size distributions closely followed each other for each sample, and size distributions in both showed maxima at the same nanoparticle size. The SAXS-measured nanoparticle diameters were slightly larger than the respective diameters measured by TEM. This was because SAXS measures an agglomerate consisting of several particles as one big particle which slightly increased the mean diameter. TEM- and SAXS-measured mean diameters when plotted together showed similar trend in the variation in the size as the laser power was changed which along with extremely similar size distributions for TEM and SAXS validated the application of SAXS for size distribution measurement of the synthesized TiO2 nanoparticles.

  15. Pulsed Laser Ablation-Induced Green Synthesis of TiO2 Nanoparticles and Application of Novel Small Angle X-Ray Scattering Technique for Nanoparticle Size and Size Distribution Analysis.

    Science.gov (United States)

    Singh, Amandeep; Vihinen, Jorma; Frankberg, Erkka; Hyvärinen, Leo; Honkanen, Mari; Levänen, Erkki

    2016-12-01

    This paper aims to introduce small angle X-ray scattering (SAXS) as a promising technique for measuring size and size distribution of TiO2 nanoparticles. In this manuscript, pulsed laser ablation in liquids (PLAL) has been demonstrated as a quick and simple technique for synthesizing TiO2 nanoparticles directly into deionized water as a suspension from titanium targets. Spherical TiO2 nanoparticles with diameters in the range 4-35 nm were observed with transmission electron microscopy (TEM). X-ray diffraction (XRD) showed highly crystalline nanoparticles that comprised of two main photoactive phases of TiO2: anatase and rutile. However, presence of minor amounts of brookite was also reported. The traditional methods for nanoparticle size and size distribution analysis such as electron microscopy-based methods are time-consuming. In this study, we have proposed and validated SAXS as a promising method for characterization of laser-ablated TiO2 nanoparticles for their size and size distribution by comparing SAXS- and TEM-measured nanoparticle size and size distribution. SAXS- and TEM-measured size distributions closely followed each other for each sample, and size distributions in both showed maxima at the same nanoparticle size. The SAXS-measured nanoparticle diameters were slightly larger than the respective diameters measured by TEM. This was because SAXS measures an agglomerate consisting of several particles as one big particle which slightly increased the mean diameter. TEM- and SAXS-measured mean diameters when plotted together showed similar trend in the variation in the size as the laser power was changed which along with extremely similar size distributions for TEM and SAXS validated the application of SAXS for size distribution measurement of the synthesized TiO2 nanoparticles.

  16. Anisotropic imaging performance in indirect x-ray imaging detectors.

    Science.gov (United States)

    Badano, Aldo; Kyprianou, Iacovos S; Sempau, Josep

    2006-08-01

    We report on the variability in imaging system performance due to oblique x-ray incidence, and the associated transport of quanta (both x rays and optical photons) through the phosphor, in columnar indirect digital detectors. The analysis uses MANTIS, a combined x-ray, electron, and optical Monte Carlo transport code freely available. We describe the main features of the simulation method and provide some validation of the phosphor screen models considered in this work. We report x-ray and electron three-dimensional energy deposition distributions and point-response functions (PRFs), including optical spread in columnar phosphor screens of thickness 100 and 500 microm, for 19, 39, 59, and 79 keV monoenergetic x-ray beams incident at 0 degrees, 10 degrees, and 15 degrees. In addition, we present pulse-height spectra for the same phosphor thickness, x-ray energies, and angles of incidence. Our results suggest that the PRF due to the phosphor blur is highly nonsymmetrical, and that the resolution properties of a columnar screen in a tomographic, or tomosynthetic imaging system varies significantly with the angle of x-ray incidence. Moreover, we find that the noise due to the variability in the number of light photons detected per primary x-ray interaction, summarized in the information or Swank factor, is somewhat independent of thickness and incidence angle of the x-ray beam. Our results also suggest that the anisotropy in the PRF is not less in screens with absorptive backings, while the noise introduced by variations in the gain and optical transport is larger. Predictions from MANTIS, after additional validation, can provide the needed understanding of the extent of such variations, and eventually, lead to the incorporation of the changes in imaging performance with incidence angle into the reconstruction algorithms for volumetric x-ray imaging systems.

  17. Neutron Stars in X-ray Binaries and their Environments

    Science.gov (United States)

    Paul, Biswajit

    2017-09-01

    Neutron stars in X-ray binary systems are fascinating objects that display a wide range of timing and spectral phenomena in the X-rays. Not only parameters of the neutron stars, like magnetic field strength and spin period evolve in their active binary phase, the neutron stars also affect the binary systems and their immediate surroundings in many ways. Here we discuss some aspects of the interactions of the neutron stars with their environments that are revelaed from their X-ray emission. We discuss some recent developments involving the process of accretion onto high magnetic field neutron stars: accretion stream structure and formation, shape of pulse profile and its changes with accretion torque. Various recent studies of reprocessing of X-rays in the accretion disk surface, vertical structures of the accretion disk and wind of companion star are also discussed here. The X-ray pulsars among the binary neutron stars provide excellent handle to make accurate measurement of the orbital parameters and thus also evolution of the binray orbits that take place over time scale of a fraction of a million years to tens of millions of years. The orbital period evolution of X-ray binaries have shown them to be rather complex systems. Orbital evolution of X-ray binaries can also be carried out from timing of the X-ray eclipses and there have been some surprising results in that direction, including orbital period glitches in two X-ray binaries and possible detection of the most massive circum-binary planet around a Low Mass X-ray Binary.

  18. X-ray emission as a diagnostic from pseudospark-sourced electron beams

    Energy Technology Data Exchange (ETDEWEB)

    Bowes, D., E-mail: david.bowes@strath.ac.uk [Department of Physics, SUPA, University of Strathclyde, Glasgow G4 0NG (United Kingdom); Yin, H.; He, W.; Zhang, L.; Cross, A.W.; Ronald, K.; Phelps, A.D.R. [Department of Physics, SUPA, University of Strathclyde, Glasgow G4 0NG (United Kingdom); Chen, D.; Zhang, P. [Computed Tomography Lab, School of Mathematical Sciences, Capital Normal University, Beijing 100048 (China); Chen, X.; Li, D. [Department of Electronic Engineering, Queen Mary University of London, London E1 4NS (United Kingdom)

    2014-09-15

    X-ray emission has been achieved using an electron beam generated by a pseudospark low-pressure discharge and utilised as a diagnostic for beam detection. A 300 A, 34 kV PS-sourced electron beam pulse of 3 mm diameter impacting on a 0.1 mm-thick molybdenum target generated X-rays which were detected via the use of a small, portable X-ray detector. Clear X-ray images of a micro-sized object were captured using an X-ray photodetector. This demonstrates the inducement of proton induced X-ray emission (PIXE) not only as an indicator of beam presence but also as a future X-ray source for small-spot X-ray imaging of materials.

  19. X-ray emission simulation from hollow atoms produced by high intensity laser irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Moribayashi, Kengo; Sasaki, Akira; Zhidkov, A. [Japan Atomic Energy Research Inst., Kansai Research Establishment, Neyagawa, Osaka (Japan); Suto, Keiko [Nara Women' s Univ., Graduate School of Human Culture, Nara (Japan); Kagawa, Takashi [Nara Women' s Univ., Department of Physics, Nara (Japan)

    2001-10-01

    We theoretically study the x-ray emission from hollow atoms produced by collisions of multiply charged ions accelerated by a short pulse laser with a solid or foil. By using the multistep-capture-and-loss (MSCL) model a high conversion efficiency to x-rays in an ultrafast atomic process is obtained. It is also proposed to apply this x-ray emission process to the x-ray source. For a few keV x-rays this x-ray source has a clear advantage. The number of x-ray photons increases as the laser energy becomes larger. For a laser energy of 10 J, the number of x-ray photons of 3x10{sup 11} is estimated. (author)

  20. Ultrafast Time Resolved X-ray Diffraction Studies of Laser Heated Metals and Semiconductors

    Science.gov (United States)

    Chen, Peilin; Tomov, I. V.; Rentzepis, P. M.

    1998-03-01

    Time resolved hard x-ray diffraction has been employed to study the dynamics of lattice structure deformation. When laser pulse energy is deposited in a material it generates a non uniform transient temperature distribution, which alters the lattice structure of the crystal. The deformed crystal lattice will change the angle of diffraction for a monochromatic x-ray beam. We report picosecond and nanosecond time resolved x-ray diffraction measurements of the lattice temperature distribution, transient structure and stress, in Pt (111) and GaAs (111) crystals, caused by pulsed UV laser irradiation. An ArF excimer laser operated at 300 Hz was used, both, to drive an x-ray diode with copper anode and heat the crystal. Bragg diffracted x-ray radiation was recorded by a direct imaging x-ray CCD. Changes in the diffraction patterns induced by a few millijouls pulse energy were observed at different time delays between the laser heating pulse and the x-ray probing pulse. A kinematical model for time resolved x-ray diffraction was used to analyze the experimental data. Good agreement between the measured and calculated scattered x-ray intensities profiles was achieved, indicating that detailed time resolved x-ray diffraction measurements can be made with nanosecond and picosecond resolution for small temperature changes. Our system can detect changes in the lattice spacing of about 10-3 A.