WorldWideScience

Sample records for high accuracy x-ray

  1. Identifying wrist fracture patients with high accuracy by automatic categorization of X-ray reports.

    Science.gov (United States)

    de Bruijn, Berry; Cranney, Ann; O'Donnell, Siobhan; Martin, Joel D; Forster, Alan J

    2006-01-01

    The authors performed this study to determine the accuracy of several text classification methods to categorize wrist x-ray reports. We randomly sampled 751 textual wrist x-ray reports. Two expert reviewers rated the presence (n = 301) or absence (n = 450) of an acute fracture of wrist. We developed two information retrieval (IR) text classification methods and a machine learning method using a support vector machine (TC-1). In cross-validation on the derivation set (n = 493), TC-1 outperformed the two IR based methods and six benchmark classifiers, including Naive Bayes and a Neural Network. In the validation set (n = 258), TC-1 demonstrated consistent performance with 93.8% accuracy; 95.5% sensitivity; 92.9% specificity; and 87.5% positive predictive value. TC-1 was easy to implement and superior in performance to the other classification methods.

  2. ISPA - a high accuracy X-ray and gamma camera Exhibition LEPFest 2000

    CERN Multimedia

    2000-01-01

    ISPA offers ... Ten times better resolution than Anger cameras High efficiency single gamma counting Noise reduction by sensitivity to gamma energy ...for Single Photon Emission Computed Tomography (SPECT)

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

    NARCIS (Netherlands)

    Groot, F.M.F. de

    2000-01-01

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

  4. Performing elemental microanalysis with high accuracy and high precision by scanning electron microscopy/silicon drift detector energy-dispersive X-ray spectrometry (SEM/SDD-EDS).

    Science.gov (United States)

    Newbury, Dale E; Ritchie, Nicholas W M

    Electron-excited X-ray microanalysis performed in the scanning electron microscope with energy-dispersive X-ray spectrometry (EDS) is a core technique for characterization of the microstructure of materials. The recent advances in EDS performance with the silicon drift detector (SDD) enable accuracy and precision equivalent to that of the high spectral resolution wavelength-dispersive spectrometer employed on the electron probe microanalyzer platform. SDD-EDS throughput, resolution, and stability provide practical operating conditions for measurement of high-count spectra that form the basis for peak fitting procedures that recover the characteristic peak intensities even for elemental combination where severe peak overlaps occur, such PbS, MoS2, BaTiO3, SrWO4, and WSi2. Accurate analyses are also demonstrated for interferences involving large concentration ratios: a major constituent on a minor constituent (Ba at 0.4299 mass fraction on Ti at 0.0180) and a major constituent on a trace constituent (Ba at 0.2194 on Ce at 0.00407; Si at 0.1145 on Ta at 0.0041). Accurate analyses of low atomic number elements, C, N, O, and F, are demonstrated. Measurement of trace constituents with limits of detection below 0.001 mass fraction (1000 ppm) is possible within a practical measurement time of 500 s.

  5. The high accuracy model of the 19 July 2012 solar flare: kinetic description, calculations of X-Ray and microwave emission

    Science.gov (United States)

    Gritsyk, Pavel; Somov, Boris

    2016-04-01

    The limb white-light solar flare M7.7 class was observed at the 19 July 2012 at 05:58UT by RHESSI, GOES and SDO with high spectral, spatial and temporal resolution. These new data make possible to test modern models of solar flares. The flare, which considered here, locates in the picture plane, so we well see two different hard X-ray sources: footpoint and above-the-loop-top. The loop was observed in whit-light and microwave wavelengths. The key part of the presented work is high accuracy kinetic model, which describe behavior of electrons in the target - solar flare loop. We interpret the footpoint source in approximation of the thick target model with reverse current and above-the-loop-top source - in the thin target approximation. The microwave spectrum in the range from 1 to 50 GHz was calculated. Our results fit well the observational data, particularly so important parameter as hard X-Ray spectral index. But intensity of emission of the coronal source was estimated incorrect, it was low than observed. This problem can be solved by taking into account effects of particles acceleration in the collapsing magnetic trap, when fast electrons receive additional energy without changing the index of their energy spectrum. In the result we have flux ~ 5 1010 erg cm-2 s-1 for electrons with energies more then 15 keV, that ~ 5 times larger then in the case classical thick target model. Accordingly , so high flux of electrons to the Chromosphere provides effective heating of the cold plasma in the target, but the reverse current electric field restrict depth of the electron penetration. Received in this work estimates may be used for interpretation of the solar flare optical source formation and evolution.

  6. High-resolution accelerator alignment using x-ray optics

    Directory of Open Access Journals (Sweden)

    Bingxin Yang

    2006-03-01

    Full Text Available We propose a novel alignment technique utilizing the x-ray beam of an undulator in conjunction with pinholes and position-sensitive detectors for positioning components of the accelerator, undulator, and beam line in an x-ray free-electron laser. Two retractable pinholes at each end of the undulator define a stable and reproducible x-ray beam axis (XBA. Targets are precisely positioned on the XBA using a pinhole camera technique. Position-sensitive detectors responding to both x-ray and electron beams enable direct transfer of the position setting from the XBA to the electron beam. This system has the potential to deliver superior alignment accuracy (1–3   μm for target pinholes in the transverse directions over a long distance (200 m or longer. It can be used to define the beam axis of the electron-beam–based alignment, enabling high reproducibility of the latter. This x-ray–based concept should complement the electron-beam–based alignment and the existing survey methods to raise the alignment accuracy of long accelerators to an unprecedented level. Further improvement of the transverse accuracy using x-ray zone plates will be discussed. We also propose a concurrent measurement scheme during accelerator operation to allow real-time feedback for transverse position correction.

  7. High precision x ray lithographic masks

    Science.gov (United States)

    Pease, R. F.; Browning, R.

    1992-09-01

    This contract period was first concerned with winding up the projects on the embedded X-ray Mask structure and on the 'quantum lithography' idea. As a result of developments elsewhere it became clear that among the most critical issues in achieving high precision X-ray masks were those associated with achieving high precision in both feature size and feature placement in electron beam lithography. Most of the effort in this reporting period was aimed at achieving precision in feature size; notably an attack on the problem of proximity effects. There were two approaches: (1) A short term approach aimed at correcting effects in existing electron beam pattern generators (notably the ETEC MEBES 3 and 4) for feature sizes down 500 nm; and (2) A long term approach aimed at avoiding proximity effects by employing low energy electron exposure for feature size below 500 nm.

  8. The accuracy of the crystal chemical parameters at high-pressure conditions from single-crystal X-ray diffraction in diamond-anvil cell

    DEFF Research Database (Denmark)

    Periotto, Benedetta

    applications also in the materials science as it can provide useful information about the properties and performance of new materials. Over the past decades, the research in this field has been strongly developed due to the advances in computer capabilities and to the technological improvements of X-ray...... instruments. At the same time, the high-pressure experiments have benefited by the strong improvements on the high-pressure devices, in particular the diamond-anvil cell (DAC). The aim of this research project is to assess the quality of the data obtained by means of the single-crystal X-ray diffraction...... technique through the study of different mineral phases. The procedure for setting up an experiment under high-pressure conditions, using a single crystal as sample held within a DAC, are presented here with all the details of the in situ measurements at high-pressure conditions. The research project...

  9. X-ray photoelectron spectroscopy, high-resolution X-ray diffraction ...

    Indian Academy of Sciences (India)

    Powder X-ray diffraction studies were carried out on doped lithium niobate for phase identification. High-resolution X-ray diffraction technique was used to study the crystalline quality through full-width at half-maximum values. The refractive index values are more for doped samples than for pure sample as determined by ...

  10. X-RAY POLARIZATION FROM HIGH-MASS X-RAY BINARIES

    Energy Technology Data Exchange (ETDEWEB)

    Kallman, T. [NASA/GSFC, Code 662, Greenbelt, MD 20771 (United States); Dorodnitsyn, A. [Department of Astronomy, University of Maryland, College Park, MD 20742 (United States); Blondin, J. [Department of Physics, North Carolina State University, Raleigh, NC 27695-8202 (United States)

    2015-12-10

    X-ray astronomy allows study of objects that may be associated with compact objects, i.e., neutron stars or black holes, and also may contain strong magnetic fields. Such objects are categorically nonspherical, and likely noncircular when projected on the sky. Polarization allows study of such geometric effects, and X-ray polarimetry is likely to become feasible for a significant number of sources in the future. Potential targets for future X-ray polarization observations are the high-mass X-ray binaries (HMXBs), which consist of a compact object in orbit with an early-type star. In this paper we show that X-ray polarization from HMXBs has a distinct signature that depends on the source inclination and orbital phase. The presence of the X-ray source displaced from the star creates linear polarization even if the primary wind is spherically symmetric whenever the system is viewed away from conjunction. Direct X-rays dilute this polarization whenever the X-ray source is not eclipsed; at mid-eclipse the net polarization is expected to be small or zero if the wind is circularly symmetric around the line of centers. Resonance line scattering increases the scattering fraction, often by large factors, over the energy band spanned by resonance lines. Real winds are not expected to be spherically symmetric, or circularly symmetric around the line of centers, owing to the combined effects of the compact object gravity and ionization on the wind hydrodynamics. A sample calculation shows that this creates polarization fractions ranging up to tens of percent at mid-eclipse.

  11. High Resolution X-ray Views of Solar System Objects

    Science.gov (United States)

    Branduardi-Raymont, Graziella

    2011-05-01

    Over the last decade Chandra, and XMM-Newton, have revealed the beauty and multiplicity of X-ray emissions in our solar system: high resolution data, in both spectral and spatial domains, have been crucial in disentangling the physical processes at work. The talk will review the main findings in this area at the boundary between astrophysics and planetary science, and will show how the solar system offers `next door’ examples of widespread astrophysical phenomena. Jupiter shows bright X-ray aurorae, arising from the interactions of local and/or solar wind ions, and electrons, with its powerful magnetic environment: the ions undergo charge exchange with atmospheric neutrals and generate soft X-ray line emission, and the electrons give rise to bremsstrahlung X-rays. Chandra's unparalleled spatial resolution has shown how the X-ray footprints of the electrons in the aurorae coincide with the bright FUV auroral oval, indicating that the same electron population is likely to be at the origin of both emissions. Moreover, Jupiter's disk scatters solar X-rays, displaying a spectrum that closely resembles that of solar flares. Saturn has not revealed X-ray aurorae (yet), but its disk X-ray brightness, like Jupiter's, is strictly correlated with the Sun's X-ray output. A bright X-ray spot has also been resolved by Chandra on the eastern ansa of Saturn's rings, and its spectrum suggests an origin in the fluorescent scattering of solar X-rays on the rings icy particles. Both Mars and Venus have X-ray emitting disks and exospheres, which can be clearly resolved at high spectral and spatial resolution. And the Earth has bright X-ray aurorae that have been targets of Chandra observations. Finally, comets, with their extended neutral comae and extremely line-rich X-ray spectra, are spectacular X-ray sources, and ideal probes of the conditions of the solar wind in the Sun's proximity.

  12. Reabsorption of soft x-ray emission at high x-ray free-electron laser fluences.

    Science.gov (United States)

    Schreck, Simon; Beye, Martin; Sellberg, Jonas A; McQueen, Trevor; Laksmono, Hartawan; Kennedy, Brian; Eckert, Sebastian; Schlesinger, Daniel; Nordlund, Dennis; Ogasawara, Hirohito; Sierra, Raymond G; Segtnan, Vegard H; Kubicek, Katharina; Schlotter, William F; Dakovski, Georgi L; Moeller, Stefan P; Bergmann, Uwe; Techert, Simone; Pettersson, Lars G M; Wernet, Philippe; Bogan, Michael J; Harada, Yoshihisa; Nilsson, Anders; Föhlisch, Alexander

    2014-10-10

    We report on oxygen K-edge soft x-ray emission spectroscopy from a liquid water jet at the Linac Coherent Light Source. We observe significant changes in the spectral content when tuning over a wide range of incident x-ray fluences. In addition the total emission yield decreases at high fluences. These modifications result from reabsorption of x-ray emission by valence-excited molecules generated by the Auger cascade. Our observations have major implications for future x-ray emission studies at intense x-ray sources. We highlight the importance of the x-ray pulse length with respect to the core-hole lifetime.

  13. High-resolution x-ray characterization of mosaic crystals for hard x-ray astronomy

    Science.gov (United States)

    Ferrari, Claudio; Buffagni, Elisa; Marchini, Laura; Zappettini, Andrea

    2012-04-01

    GaAs, Cu, CdTe, and CdZnTe crystals have been studied as optical elements for lenses for hard x-ray astronomy. High-resolution x-ray diffraction at 8 keV in Bragg geometry and at synchrotron at energies up to 500 keV in Laue geometry has been used. A good agreement was found between the mosaicity evaluated in Bragg geometry at 8 keV with x-ray penetration of the order of few tens of micrometers and that derived at synchrotron in transmission Laue geometry at higher x-ray energies. Mosaicity values in a range between a few to 150 arcsec were found in all the samples but, due to the presence of crystal grains in the cm range, CdTe and CdZnTe crystals were found not suitable. Cu crystals exhibit a mosaicity of the order of several arcmin; they indeed were found to be severely affected by cutting damage which could only be removed with a very deep etching. The full width at half maximum of the diffraction peaks decreased at higher x-ray energies showing that the peak broadening is affected by crystallite size. GaAs crystals grown by Czochralski method showed a mosaic spread up to 30 arcsec and good diffraction efficiency up to energies of 500 keV. The use of thermal treatments as a possible method to increase the mosaic spread was also evaluated.

  14. X-ray framing camera for pulsed, high current, electron beam x-ray sources

    CERN Document Server

    Failor, B H; Riordan, j c; Lojewski, D Y

    2007-01-01

    High power x-ray sources built for nuclear weapons effects testing are evolving toward larger overall diameters and smaller anode cathode gaps. We describe a framing camera developed to measure the time-evolution of these 20-50 ns pulsed x-ray sources produced by currents in the 1.5-2.5 MA range and endpoint voltages between 0.2 and 1.5 MV. The camera has up to 4 frames with 5 ns gate widths; the frames are separated by 5 ns. The image data are recorded electronically with a gated intensified CCD camera and the data are available immediately following a shot. A fast plastic scintillator (2.1 ns decay time) converts the x-rays to visible light and, for high sensitivity, a fiber optic imaging bundle carries the light to the CCD input. Examples of image data are shown.

  15. How calibration and reference spectra affect the accuracy of absolute soft X-ray solar irradiance measured by the SDO/EVE/ESP during high solar activity

    Science.gov (United States)

    Didkovsky, Leonid; Wieman, Seth; Woods, Thomas

    2016-10-01

    The Extreme ultraviolet Spectrophotometer (ESP), one of the channels of SDO's Extreme ultraviolet Variability Experiment (EVE), measures solar irradiance in several EUV and soft x-ray (SXR) bands isolated using thin-film filters and a transmission diffraction grating, and includes a quad-diode detector positioned at the grating zeroth-order to observe in a wavelength band from about 0.1 to 7.0 nm. The quad diode signal also includes some contribution from shorter wavelength in the grating's first-order and the ratio of zeroth-order to first-order signal depends on both source geometry, and spectral distribution. For example, radiometric calibration of the ESP zeroth-order at the NIST SURF BL-2 with a near-parallel beam provides a different zeroth-to-first-order ratio than modeled for solar observations. The relative influence of "uncalibrated" first-order irradiance during solar observations is a function of the solar spectral irradiance and the locations of large Active Regions or solar flares. We discuss how the "uncalibrated" first-order "solar" component and the use of variable solar reference spectra affect determination of absolute SXR irradiance which currently may be significantly overestimated during high solar activity.

  16. High-resolution X-ray diffraction studies of multilayers

    DEFF Research Database (Denmark)

    Christensen, Finn Erland; Hornstrup, Allan; Schnopper, H. W.

    1988-01-01

    High-resolution X-ray diffraction studies of the perfection of state-of-the-art multilayers are presented. Data were obtained using a triple-axis perfect-crystal X-ray diffractometer. Measurements reveal large-scale figure errors in the substrate. A high-resolution triple-axis set up is required...

  17. Development of high resolution imaging detectors for x ray astronomy

    Science.gov (United States)

    Murray, S. S.; Schwartz, D. A.

    1992-01-01

    This final report summarizes our past activities and discusses the work performed over the period of 1 April 1990 through 1 April 1991 on x-ray optics, soft x-ray (0.1 - 10 KeV) imaging detectors, and hard x-ray (10 - 300 KeV) imaging detectors. If microchannel plates (MCPs) can be used to focus x-rays with a high efficiency and good angular resolution, they will revolutionize the field of x-ray optics. An x-ray image of a point source through an array of square MCP pores compared favorably with our ray tracing model for the MCP. Initial analysis of this image demonstrates the feasibility of MCPs for soft x-rays. Our work continues with optimizing the performance of our soft x-ray MCP imaging detectors. This work involves readout technology that should provide improved MCP readout devices (thin film crossed grid, curved, and resistive sheets), defect removal in MCPs, and photocathode optimization. In the area of hard x-ray detector development we have developed two different techniques for producing a CsI photocathode thickness of 10 to 100 microns, such that it is thick enough to absorb the high energy x-rays and still allow the photoelectrons to escape to the top MCP of a modified soft x-ray imaging detector. The methods involve vacuum depositing a thick film of CsI on a strong back, and producing a converter device that takes the place of the photocathode.

  18. High energy resolution off-resonant X-ray spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Wojciech, Blachucki [Univ. of Fribourg (Switzerland). Dept. of Physics

    2015-10-16

    This work treats of the high energy resolution off-resonant X-ray spectroscopy (HEROS) method of determining the density of unoccupied electronic states in the vicinity of the absorption edge. HEROS is an alternative to the existing X-ray absorption spectroscopy (XAS) methods and opens the way for new studies not achievable before.

  19. Synchrotron radiation micro-X-ray fluorescence analysis: A tool to increase accuracy in microscopic analysis

    CERN Document Server

    Adams, F

    2003-01-01

    Microscopic X-ray fluorescence (XRF) analysis has potential for development as a certification method and as a calibration tool for other microanalytical techniques. The interaction of X-rays with matter is well understood and modelling studies show excellent agreement between experimental data and calculations using Monte Carlo simulation. The method can be used for a direct iterative calculation of concentrations using available high accuracy physical constants. Average accuracy is in the range of 3-5% for micron sized objects at concentration levels of less than 1 ppm with focused radiation from SR sources. The end-station ID18F of the ESRF is dedicated to accurate quantitative micro-XRF analysis including fast 2D scanning with collection of full X-ray spectra. Important aspects of the beamline are the precise monitoring of the intensity of the polarized, variable energy beam and the high reproducibility of the set-up measurement geometry, instrumental parameters and long-term stability.

  20. Final Report - X-ray Studies of Highly Correlated Systems

    Energy Technology Data Exchange (ETDEWEB)

    Burns, Clement [Western Michigan Univ., Kalamazoo MI (United States)

    2017-11-27

    The overall goal of the research was to improve the capabilities of x-ray synchrotron instrumentation to enable cutting-edge research in condensed matter physics. The main goal of the current grant cycle was to find a method to measure the polarization of the scattered x-ray in resonant inelastic x-ray scattering. To do this, we developed a polarization analysis apparatus using a thin, toroidally bent single crystal, which could be set to reflect one or the other of the two polarization components in the scattered x-ray beam. Resonant x-ray scattering measurements were also carried out on interfaces and the charge density wave in high temperature superconducting materials.

  1. Compton spectra of atoms at high x-ray intensity

    Science.gov (United States)

    Son, Sang-Kil; Geffert, Otfried; Santra, Robin

    2017-03-01

    Compton scattering is the nonresonant inelastic scattering of an x-ray photon by an electron and has been used to probe the electron momentum distribution in gas-phase and condensed-matter samples. In the low x-ray intensity regime, Compton scattering from atoms dominantly comes from bound electrons in neutral atoms, neglecting contributions from bound electrons in ions and free (ionized) electrons. In contrast, in the high x-ray intensity regime, the sample experiences severe ionization via x-ray multiphoton multiple ionization dynamics. Thus, it becomes necessary to take into account all the contributions to the Compton scattering signal when atoms are exposed to high-intensity x-ray pulses provided by x-ray free-electron lasers (XFELs). In this paper, we investigate the Compton spectra of atoms at high x-ray intensity, using an extension of the integrated x-ray atomic physics toolkit, xatom. As the x-ray fluence increases, there is a significant contribution from ionized electrons to the Compton spectra, which gives rise to strong deviations from the Compton spectra of neutral atoms. The present study provides not only understanding of the fundamental XFEL-matter interaction but also crucial information for single-particle imaging experiments, where Compton scattering is no longer negligible. , which features invited work from the best early-career researchers working within the scope of J. Phys. B. This project is part of the Journal of Physics series’ 50th anniversary celebrations in 2017. Sang-Kil Son was selected by the Editorial Board of J. Phys. B as an Emerging Leader.

  2. Simulation of high currents in x-ray flash tubes

    Science.gov (United States)

    Germer, R.; Sato, E.

    2008-11-01

    The discharge in linear plasma X-ray flash tubes ( Sato tubes ) is simulated. For the geometry of a cylinder cathode outside and an anode in the centre, the electrical fields and potentials are calculated and the propagation of electrons are studied. Space charge limits the current in the initial phase strongly. Replacing the vacuum by plasma from the anode evaporation, it is possible to get increasing current and strong X-ray pulses. Space charge is important for the high intensity X-ray production up to the end of the emission.

  3. X-ray optics high-energy-resolution applications

    CERN Document Server

    Shvyd’ko, Yuri

    2004-01-01

    The generation of radiation with well-defined frequency and wavelength, and the ability to precisely determine these quantities, are of fundamental importance in physics and other natural sciences Monochromatic radiation enables both very accurate structure determinations and studies of the dynamics of living and non-living matter It is crucial for the realization of standards of time and length, for the determination of fundamental constants, and for many other aspects of basic research Bragg backscattering from perfect crystals is a tool for creating, manipulating, and analyzing x-rays with highest spectral purity It has the unique feature of selecting x-rays with narrow spectral bandwidth This book describes the theoretical foundations and principles of x-ray crystal optics with high spectral resolution Various experimental studies and applications are presented and the author also addresses the development of instrumentation, such as high-resolution x-ray monochromators, analyzers, wavelength meters, reso...

  4. Radial lens distortion correction with sub-pixel accuracy for X-ray micro-tomography.

    Science.gov (United States)

    Vo, Nghia T; Atwood, Robert C; Drakopoulos, Michael

    2015-12-14

    Distortion correction or camera calibration for an imaging system which is highly configurable and requires frequent disassembly for maintenance or replacement of parts needs a speedy method for recalibration. Here we present direct techniques for calculating distortion parameters of a non-linear model based on the correct determination of the center of distortion. These techniques are fast, very easy to implement, and accurate at sub-pixel level. The implementation at the X-ray tomography system of the I12 beamline, Diamond Light Source, which strictly requires sub-pixel accuracy, shows excellent performance in the calibration image and in the reconstructed images.

  5. High-resolution x-ray photoemission spectra of silver

    DEFF Research Database (Denmark)

    Barrie, A.; Christensen, N. E.

    1976-01-01

    An electron spectrometer fitted with an x-ray monochromator for Al Kα1,2 radiation (1486.6 eV) has been used to record high-resolution x-ray photoelectron spectra for the 4d valence band as well as the 3d spin doublet in silver. The core-level spectrum has a line shape that can be described...

  6. Progress in high-resolution x-ray holographic microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Jacobsen, C.; Kirz, J.; Howells, M.; McQuaid, K.; Rothman, S.; Feder, R.; Sayre, D.

    1987-07-01

    Among the various types of x-ray microscopes that have been demonstrated, the holographic microscope has had the largest gap between promise and performance. The difficulties of fabricating x-ray optical elements have led some to view holography as the most attractive method for obtaining the ultimate in high resolution x-ray micrographs; however, we know of no investigations prior to 1987 that clearly demonstrated submicron resolution in reconstructed images. Previous efforts suffered from problems such as limited resolution and dynamic range in the recording media, low coherent x-ray flux, and aberrations and diffraction limits in visible light reconstruction. We have addressed the recording limitations through the use of an undulator x-ray source and high-resolution photoresist recording media. For improved results in the readout and reconstruction steps, we have employed metal shadowing and transmission electron microscopy, along with numerical reconstruction techniques. We believe that this approach will allow holography to emerge as a practical method of high-resolution x-ray microscopy. 30 refs., 4 figs.

  7. Highly porous nanoberyllium for X-ray beam speckle suppression

    Energy Technology Data Exchange (ETDEWEB)

    Goikhman, Alexander, E-mail: agoikhman@ymail.com; Lyatun, Ivan; Ershov, Petr [Immanuel Kant Baltic Federal University, Nevskogo str. 14, Kaliningrad 236041 (Russian Federation); Snigireva, Irina [European Synchrotron Radiation Facility, BP 220, 38043 Grenoble (France); Wojda, Pawel [Immanuel Kant Baltic Federal University, Nevskogo str. 14, Kaliningrad 236041 (Russian Federation); Gdańsk University of Technology, 11/12 G. Narutowicza, Gdańsk 80-233 (Poland); Gorlevsky, Vladimir; Semenov, Alexander; Sheverdyaev, Maksim; Koletskiy, Viktor [A. A. Bochvar High-Technology Scientific Research Institute for Inorganic Materials, Rogova str. 5a, Moscow 123098 (Russian Federation); Snigirev, Anatoly [Immanuel Kant Baltic Federal University, Nevskogo str. 14, Kaliningrad 236041 (Russian Federation); European Synchrotron Radiation Facility, BP 220, 38043 Grenoble (France)

    2015-04-09

    A speckle suppression device containing highly porous nanoberyllium is proposed for manipulating the spatial coherence length and removing undesirable speckle structure during imaging experiments. This paper reports a special device called a ‘speckle suppressor’, which contains a highly porous nanoberyllium plate squeezed between two beryllium windows. The insertion of the speckle suppressor in an X-ray beam allows manipulation of the spatial coherence length, thus changing the effective source size and removing the undesirable speckle structure in X-ray imaging experiments almost without beam attenuation. The absorption of the nanoberyllium plate is below 1% for 1 mm thickness at 12 keV. The speckle suppressor was tested on the ID06 ESRF beamline with X-rays in the energy range from 9 to 15 keV. It was applied for the transformation of the phase–amplitude contrast to the pure amplitude contrast in full-field microscopy.

  8. A MEMS-based high frequency x-ray chopper

    Energy Technology Data Exchange (ETDEWEB)

    Siria, A; Schwartz, W; Chevrier, J [Institut Neel, CNRS-Universite Joseph Fourier Grenoble, BP 166, F-38042 Grenoble Cedex 9 (France); Dhez, O; Comin, F [ESRF, 6 rue Jules Horowitz, F-38043 Grenoble Cedex 9 (France); Torricelli, G [Department of Physics and Astronomy, University of Leicester, University Road, Leicester LE1 7RH (United Kingdom)

    2009-04-29

    Time-resolved x-ray experiments require intensity modulation at high frequencies (advanced rotating choppers have nowadays reached the kHz range). We here demonstrate that a silicon microlever oscillating at 13 kHz with nanometric amplitude can be used as a high frequency x-ray chopper. We claim that using micro-and nanoelectromechanical systems (MEMS and NEMS), it will be possible to achieve higher frequencies in excess of hundreds of megahertz. Working at such a frequency can open a wealth of possibilities in chemistry, biology and physics time-resolved experiments.

  9. A MEMS-based high frequency x-ray chopper.

    Science.gov (United States)

    Siria, A; Dhez, O; Schwartz, W; Torricelli, G; Comin, F; Chevrier, J

    2009-04-29

    Time-resolved x-ray experiments require intensity modulation at high frequencies (advanced rotating choppers have nowadays reached the kHz range). We here demonstrate that a silicon microlever oscillating at 13 kHz with nanometric amplitude can be used as a high frequency x-ray chopper. We claim that using micro-and nanoelectromechanical systems (MEMS and NEMS), it will be possible to achieve higher frequencies in excess of hundreds of megahertz. Working at such a frequency can open a wealth of possibilities in chemistry, biology and physics time-resolved experiments.

  10. Production of Entangled X-Ray Photon Pairs by High Energy Electrons

    OpenAIRE

    Ispirian, K. A.; Ispiryan, M. K.

    2009-01-01

    Without developing a correct theory, the rate of the production of entangled photon pairs in the X-ray region by high energy electrons is estimated for experimental parameters used in a few experiments on X-ray parametric down conversion. Taking into account the need for X-ray entangled X-ray photons, it is proposed to begin the experimental study of such mechanism of nonlinear X-ray optics before the launch of the X-ray free electron lasers.

  11. High spatial resolution soft-x-ray microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Meyer-Ilse, W.; Medecki, H.; Brown, J.T. [Ernest Orlando Lawrence Berkeley National Lab., CA (United States)] [and others

    1997-04-01

    A new soft x-ray microscope (XM-1) with high spatial resolution has been constructed by the Center for X-ray Optics. It uses bending magnet radiation from beamline 6.1 at the Advanced Light Source, and is used in a variety of projects and applications in the life and physical sciences. Most of these projects are ongoing. The instrument uses zone plate lenses and achieves a resolution of 43 nm, measured over 10% to 90% intensity with a knife edge test sample. X-ray microscopy permits the imaging of relatively thick samples, up to 10 {mu}m thick, in water. XM-1 has an easy to use interface, that utilizes visible light microscopy to precisely position and focus the specimen. The authors describe applications of this device in the biological sciences, as well as in studying industrial applications including structured polymer samples.

  12. High resolution X-ray diffraction studies on unirradiated and ...

    Indian Academy of Sciences (India)

    High-resolution X-ray diffraction technique, employing a three-crystal monochromator–collimator ... observed by high-resolution electron microscopy in both ..... 1988 Nucl. Instrum. Meth. B34 228. Kato N 1992 J. Acta Crystallogr. A48 834. Kaur B, Bhat M, Licci F, Kumar R, Kotru P N and Bamzai K K. 2004 Nucl. Instrum. Meth ...

  13. Calculation of x-ray scattering patterns from nanocrystals at high x-ray intensity

    Directory of Open Access Journals (Sweden)

    Malik Muhammad Abdullah

    2016-09-01

    Full Text Available 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-molecular dynamics-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.

  14. Editorial: Focus on X-ray Beams with High Coherence

    Science.gov (United States)

    Robinson, Ian; Gruebel, Gerhard; Mochrie, Simon

    2010-03-01

    This editorial serves as the preface to a special issue of New Journal of Physics, which collects together solicited papers on a common subject, x-ray beams with high coherence. We summarize the issue's content, and explain why there is so much current interest both in the sources themselves and in the applications to the study of the structure of matter and its fluctuations (both spontaneous and driven). As this collection demonstrates, the field brings together accelerator physics in the design of new sources, particle physics in the design of detectors, and chemical and materials scientists who make use of the coherent beams produced. Focus on X-ray Beams with High Coherence Contents Femtosecond pulse x-ray imaging with a large field of view B Pfau, C M Günther, S Schaffert, R Mitzner, B Siemer, S Roling, H Zacharias, O Kutz, I Rudolph, R Treusch and S Eisebitt The FERMI@Elettra free-electron-laser source for coherent x-ray physics: photon properties, beam transport system and applications E Allaria, C Callegari, D Cocco, W M Fawley, M Kiskinova, C Masciovecchio and F Parmigiani Beyond simple exponential correlation functions and equilibrium dynamics in x-ray photon correlation spectroscopy Anders Madsen, Robert L Leheny, Hongyu Guo, Michael Sprung and Orsolya Czakkel The Coherent X-ray Imaging (CXI) instrument at the Linac Coherent Light Source (LCLS) Sébastien Boutet and Garth J Williams Dynamics and rheology under continuous shear flow studied by x-ray photon correlation spectroscopy Andrei Fluerasu, Pawel Kwasniewski, Chiara Caronna, Fanny Destremaut, Jean-Baptiste Salmon and Anders Madsen Exploration of crystal strains using coherent x-ray diffraction Wonsuk Cha, Sanghoon Song, Nak Cheon Jeong, Ross Harder, Kyung Byung Yoon, Ian K Robinson and Hyunjung Kim Coherence properties of the European XFEL G Geloni, E Saldin, L Samoylova, E Schneidmiller, H Sinn, Th Tschentscher and M Yurkov Fresnel coherent diffractive imaging: treatment and analysis of data G J

  15. High resolution X-ray diffraction studies on unirradiated and ...

    Indian Academy of Sciences (India)

    High-resolution X-ray diffraction technique, employing a three-crystal monochromator–collimator combination is used to study the irradiation induced defects in flux grown Sr-hexaferrite crystals irradiated with 50 MeV Li3+ ion beams at room temperature with a fluence value of 1 × 1014 ions/cm2. The diffraction curves of the ...

  16. Quantitative X-ray microradiography for high-throughput phenotyping of osteoarthritis in mice.

    Science.gov (United States)

    Waung, J A; Maynard, S A; Gopal, S; Gogakos, A; Logan, J G; Williams, G R; Bassett, J H D

    2014-10-01

    To investigate and validate digital X-ray microradiography as a novel, high-throughput and cost-effective screening approach to identify abnormal joint phenotypes in mice. Digital X-ray microradiography was used to quantify the subchondral bone mineral content (BMC) in the medial tibial plateau. Accuracy and reproducibility of the method were determined in 22 samples from C57BL/6(B6Brd;B6Dnk;B6N-Tyr(c-Brd)) wild-type mice. The method was then validated in wild-type mice that had undergone surgical destabilisation of medial meniscus (DMM) and in a genetically modified mouse strain with an established increase in trabecular bone mass. The measurement of subchondral BMC by digital X-ray microradiography had a coefficient of variation of 3.6%. Digital X-ray microradiography was able to demonstrate significantly increased subchondral BMC in the medial tibial plateau of male mice 4 and 8 weeks after DMM surgery and in female mice 8 weeks after surgery. Furthermore, digital X-ray microradiography also detected the increase in subchondral BMC in a genetically modified mouse strain with high trabecular bone mass. Quantitation of subchondral BMC by digital X-ray microradiography is a rapid, sensitive and cost-effective method to identify abnormal joint phenotypes in mice of both genders at several ages. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

  17. High temperature GaAs X-ray detectors

    Science.gov (United States)

    Lioliou, G.; Whitaker, M. D. C.; Barnett, A. M.

    2017-12-01

    Two GaAs p+-i-n+ mesa X-ray photodiodes were characterized for their electrical and photon counting X-ray spectroscopic performance over the temperature range of 100 °C to -20 °C. The devices had 10 μm thick i layers with different diameters: 200 μm (D1) and 400 μm (D2). The electrical characterization included dark current and capacitance measurements at internal electric field strengths of up to 50 kV/cm. The determined properties of the two devices were compared with previously reported results that were made with a view to informing the future development of photon counting X-ray spectrometers for harsh environments, e.g., X-ray fluorescence spectroscopy of planetary surfaces in high temperature environments. The best energy resolution obtained (Full Width at Half Maximum at 5.9 keV) decreased from 2.00 keV at 100 °C to 0.66 keV at -20 °C for the spectrometer with D1, and from 2.71 keV at 100 °C to 0.71 keV at -20 °C for the spectrometer with D2. Dielectric noise was found to be the dominant source of noise in the spectra, apart from at high temperatures and long shaping times, where the main source of photopeak broadening was found to be the white parallel noise.

  18. Bright Semiconductor Scintillator for High Resolution X-Ray Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Nagarkar, Vivek V.; Gaysinskiy, Valeriy; Ovechkina, Olena E.; Miller, Stuart; Singh, Bipin; Guo, Liang; Irving, Thomas (IIT); (Rad. Monitoring)

    2011-08-16

    We report on a novel approach to produce oxygen-doped zinc telluride (ZnTe:O), a remarkable group II-VI semiconductor scintillator, fabricated in the columnar-structured or polycrystalline forms needed to fulfill the needs of many demanding X-ray and {gamma}-ray imaging applications. ZnTe:O has one of the highest conversion efficiencies among known scintillators, emission around 680 nm (which is ideally suited for CCD sensors), high density of 6.4 g/cm{sup 3}, fast decay time of {approx}1 {micro}s with negligible afterglow, and orders of magnitude higher radiation resistance compared to commonly used scintillators. These properties allow the use of ZnTe:O in numerous applications, including X-ray imaging, nuclear medicine (particularly SPECT), room temperature radioisotope identification, and homeland security. Additionally, ZnTe:O offers distinct advantages for synchrotron-based high resolution imaging due to the absence of atomic absorption edges in the low energy range, which otherwise reduce resolution due to secondary X-ray formations. We have fabricated films of ZnTe:O using a vapor deposition technique that allows large-area structured scintillator fabrication in a time- and cost-efficient manner, and evaluated its performance for small-angle X-ray scattering (SAXS) at an Argonne National Laboratory synchrotron beamline. Details of the fabrication and characterization of the optical, scintillation and imaging properties of the ZnTe:O films are presented in this paper.

  19. Phase contrast imaging with coherent high energy X-rays

    Energy Technology Data Exchange (ETDEWEB)

    Snigireva, I. [ESRF, Grenoble (France)

    1997-02-01

    X-ray imaging concern high energy domain (>6 keV) like a contact radiography, projection microscopy and tomography is used for many years to discern the features of the internal structure non destructively in material science, medicine and biology. In so doing the main contrast formation is absorption that makes some limitations for imaging of the light density materials and what is more the resolution of these techniques is not better than 10-100 {mu}m. It was turned out that there is now way in which to overcome 1{mu}m or even sub-{mu}m resolution limit except phase contrast imaging. It is well known in optics that the phase contrast is realised when interference between reference wave front and transmitted through the sample take place. Examples of this imaging are: phase contrast microscopy suggested by Zernike and Gabor (in-line) holography. Both of this techniques: phase contrast x-ray microscopy and holography are successfully progressing now in soft x-ray region. For imaging in the hard X-rays to enhance the contrast and to be able to resolve phase variations across the beam the high degree of the time and more importantly spatial coherence is needed. Because of this it was reasonable that the perfect crystal optics was involved like Bonse-Hart interferometry, double-crystal and even triple-crystal set-up using Laue and Bragg geometry with asymmetrically cut crystals.

  20. (Li) detector characteristics on the accuracy in X-ray analysis using the

    African Journals Online (AJOL)

    A study has been carried out to show how variations in Si(Li) detector characteristics affect the accuracy of X-ray spectra evaluation. The detector characteristics investigated are Be window thickness, Au layer, Si dead layer and Si Detector Sensitive volume. For each of the detector parameters, different thickness values ...

  1. High spatial resolution hard X-ray microscope using X-ray refractive lens and phase contrast imaging experiments

    CERN Document Server

    Kohmura, Y; Takeuchi, A; Takano, H; Suzuki, Y; Ishikawa, T; Ohigashi, T; Yokosuka, H

    2001-01-01

    A high spatial resolution X-ray microscope was constructed using an X-ray refractive lens as an objective. The spatial resolution was tested using 18 keV X-ray. A 0.4 mu m line and 0.4 mu m space tantalum test pattern was successfully resolved. Using the similar setup with the addition of a phase plate, a Zernike type phase-contrast microscopy experiment was carried out for the phase retrieval of the samples. Two-dimensional phase-contrast images were successfully taken for the first time in the hard X-ray region. Images of a gold mesh sample were analyzed and the validity of this method was indicated. An improvement of the lens, however, is required for the precise phase retrieval of the samples.

  2. The Suzaku High Resolution X-Ray Spectrometer

    Science.gov (United States)

    Kelley, Richard L.; Mitsuda, Kazuhisa; Allen, Christine A.; Arsenovic, Petar; Audley, Michael D.; Bialas, Thomas G.; Boyce, Kevin R.; Boyle, Robert F.; Breon, Susan R.; Brown, Gregory V.; Cottam, Jean; Dipirro, Michael J.; Fujimoto, Ryuichi; Furusho, Tae; Gendreau, Keith C.; Gochar, Gene G.; Gonzalez, Oscar; Hirabayashi, Masayuki; Holt, Stephen S.; Inoue, Hajime; Ishida, Manabu; Ishisaki, Yoshitaka; Jones, Carol S.; Keski-Kuha, Ritva; Kilbourne, Caroline A.; McCammon, Dan; Morita, Umeyo; Moseley, S. Harvey; Mott, Brent; Narasaki, Katsuhiro; Ogawara, Yoshiaki; Ohashi, Takaya; Ota, Naomi; Panek, John S.; Porter, F. Scott; Serlemitsos, Aristides; Shirron, Peter J.; Sneiderman, Gary A.; Szymkowiak, Andrew E.; Takei, Yoh; Tveekrem, June L.; Volz, Stephen M.; Yamamoto, Mikio; Yamasaki, Noriko Y.

    2007-01-01

    The X-Ray Spectrometer (XRS) has been designed to provide the Suzaku Observatory with non-dispersive, high-resolution X-ray spectroscopy. As designed, the instrument covers the energy range 0.3 to 12keV, which encompasses the most diagnostically rich part of the X-ray band. The sensor consists of a 32-channel array of X-ray microcalorimeters, each with an energy resolution of about 6eV. The very low temperature required for operation of the array (60mK) is provided by a four-stage cooling system containing a single-stage adiabatic demagnetization refrigerator, a superfluid-helium cryostat, a solid-neon dewar, and a single-stage, Stirling-cycle cooler. The Suzaku/XRS is the first orbiting X-ray microcalorimeter spectrometer and was designed to last more than three years in orbit. The early verification phase of the mission demonstrated that the instrument worked properly and that the cryogen consumption rate was low enough to ensure a mission lifetime exceeding 3 years. However, the liquid-He cryogen was completely vaporized two weeks after opening the dewar guard vacuum vent. The problem has been traced to inadequate venting of the dewar He and Ne gases out of the spacecraft and into space. In this paper we present the design and ground testing of the XRS instrument, and then describe the in-flight performance. An energy resolution of 6eV was achieved during pre-launch tests and a resolution of 7eV was obtained in orbit. The slight degradation is due to the effects of cosmic rays.

  3. High-resolution x-ray studies of an AXAF high-energy transmission grating

    DEFF Research Database (Denmark)

    Abdali, S.; Christensen, Finn Erland; Schnopper, H. W.

    1993-01-01

    A triple axis X-ray diffractometer, designed and built at the Danish Space Research Institute, was used to make a high resolution study of the performance of a 2000 angstroms period, high energy X-ray transmission grating developed at MIT for one of the grating spectrometers on the Advanced X-ray...

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

    Science.gov (United States)

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

    2016-12-01

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

  5. High-energy X-ray spectra of five sources.

    Science.gov (United States)

    Ricker, G. R.; Mcclintock, J. E.; Gerassimenko, M.; Lewin , W. H. G.

    1973-01-01

    On October 15-16, 1970, we carried out balloon X-ray observations from Australia at energies above 15 keV. We present the high-energy X-ray spectra of three sources discovered by us, GX 301-2, GX 304-1, and GX 1 + 4. The data suggest that these high-energy sources correspond to the sources 2U 1223-62, 2U 1258-61, and 2U 1728-24 respectively. We also present the spectra for two additional sources, GX 5-1 (2U 1757-25) and GX 3 + 1 (2U 1744-26). The average intensity of the highly variable source GX 301-2 was observed to be as great as Tau X-1 in the energy range 15-50 keV.

  6. High resolution X-ray CT for advanced electronics packaging

    Science.gov (United States)

    Oppermann, M.; Zerna, T.

    2017-02-01

    Advanced electronics packaging is a challenge for non-destructive Testing (NDT). More, smaller and mostly hidden interconnects dominate modern electronics components and systems. To solve the demands of customers to get products with a high functionality by low volume, weight and price (e.g. mobile phones, personal medical monitoring systems) often the designers use System-in-Package solutions (SiP). The non-destructive testing of such devices is a big challenge. So our paper will impart fundamentals and applications for non-destructive evaluation of inner structures of electronics packaging for quality assurance and reliability investigations with a focus on X-ray methods, especially on high resolution X-ray computed tomography (CT).

  7. Lightweight and High Angular Resolution X-Ray Optics

    Science.gov (United States)

    Zhang, William W.

    2009-01-01

    The International X-ray Observatory (IXO) mission requires a lightweight and high throughput spectroscopic telescope. The fabrication, alignment, and integration of this mirror assembly require breakthroughs in many areas. In this paper we report on our recent progress in all these areas, including mirror fabrication, coating, metrology, alignment, mechanical characteristics, and their integration into mirror modules. In particular, we will also outline our plan for the next few of years, showing approaches that will progress toward reaching the 5" HPD requirement.

  8. High Precision Assembly of Thin Mirror X-ray Telescopes

    Science.gov (United States)

    Schattenburg, Mark

    Lightweight high resolution x-ray telescope optics are one of the key technologies under development for next-generation x-ray telescopes. The ultimate goal of this effort is to realize optics with spatial resolution rivaling Chandra (glass mirrors which were epoxied into place around a spindle structure. While very light weight, this process resulted in ~1 arc min resolution. We want to achieve ~100 times better with similar mass. A group at NASA GSFC has recently demonstrated an alternative thin-glass assembly procedure that has achieved ~7 arc sec resolution with x-ray tests. Further progress towards 1 arc-sec will require mirrors with improved figure, lower stress coatings, improved alignment, better metrology, and low stress bonding. Many of the difficulties with current mirror assembly practice stem from the use of epoxy as a bonding agent. Epoxy has many disadvantages, including high shrinkage, large CTE and creep, resin aging effects, water absorption, outgassing, low tensile strength, exothermicity, and requiring large amounts of time and/or heat to cure. These effects can cause errors that become â€oefrozen in― to the bond with no possibility of correction. We propose to investigate replacing epoxy with low temperature, low shrinkage solder alloys. We use these solders in conjunction with high power, millisec-long pulses from a fiber IR laser to deliver controlled amounts of heat into the bond area. We have demonstrated that laser pulses can be used to actuate carefully designed bonds by permanently compressing or expanding a very thin and brief surface melt in the solder by amounts controlled in the nanoscale range, allowing post assembly correction of the mirror mount points. We believe this technology will be one of the keys to realize a sub-1 arc-sec thin-glass x-ray telescope.

  9. Bendable X-ray Optics for High Resolution Imaging

    Science.gov (United States)

    Gubarev, M.; Ramsey, B.; Kilaru, K.; Atkins, C.; Broadway, D.

    2014-01-01

    Current state-of the-art for x-ray optics fabrication calls for either the polishing of massive substrates into high-angular-resolution mirrors or the replication of thin, lower-resolution, mirrors from perfectly figured mandrels. Future X-ray Missions will require a change in this optics fabrication paradigm in order to achieve sub-arcsecond resolution in light-weight optics. One possible approach to this is to start with perfectly flat, light-weight surface, bend it into a perfect cone, form the desired mirror figure by material deposition, and insert the resulting mirror into a telescope structure. Such an approach is currently being investigated at MSFC, and a status report will be presented detailing the results of finite element analyses, bending tests and differential deposition experiments.

  10. Flash X-Ray Generator At High Energy: GREC

    Science.gov (United States)

    Buchet, J.; Biero, H.; Fourrier, G.

    1983-08-01

    GREC, an acronym for "Generateur de Radiographie EClair" was designed for visualisation, measurements and studies on dynamic behavior of materials under high explosive loading. GREC was built in 1974 by Physics International for the CEA. Since the first operating time, 1975, this facility has been improving, taking advantage of progress in the techniques involved, especialy focusing and transport of intense electron beams. In this paper, we describe the X-ray machine and give some details on the image detection device. The pulse generator, a 80 stages Marx Generator can deliver a peak voltage of 9 MV in 1.2/us by series erection of 2 x 80 capacitors charged at + 60 kV. The Hulse-forming network, a tri-axial Blumlein, delivers a 80 ns-pulse via a 26 ohms impedance transmission line to the transport section. This transport section is a 24 cm diameter, 2 meters long, magnetic-insulated coaxial line. At the end, the X-ray radiation is emitted by bremstrahlung of the electrons impinging the tantalum anode of the dis-charge diode. The main specifications are : - electrical : 7 -MV - 180 kA - 30 ns - X-ray : Diode 1 : 400 R at 1 meter ; spot size : 20 mm Diode 2 : 100 - 300 R at 1 meter ; spot size : 4-8 mm The image acouisition device has been designed for X-raying of objects under loading of un to 50 kg of high explosives. In the paper, we give some details on the exnerimental arrangement used. Despite the severe environmental shock constraints, reasonable measurements of line-integrated density are possible.

  11. Metallic magnetic calorimeters for high resolution X-ray spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Krantz, M.; Hengstler, D.; Geist, J.; Schoetz, C.; Hassel, K.; Hendricks, S.; Keller, M.; Kempf, S.; Gastaldo, L.; Fleischmann, A.; Enss, C. [Heidelberg Univ. (Germany). KIP

    2015-07-01

    We develop microfabricated, energy dispersive particle detector arrays based on metallic magnetic calorimeters (MMCs) for high resolution X-ray spectroscopy to challenge bound-state QED calculations. Our MMCs are operated at about T=30 mK and use a paramagnetic temperature sensor, read-out by a SQUID, to measure the energy deposited by single X-ray photons. We discuss the physics of MMCs, the detector performance and the cryogenic setups for two different detector arrays. We present their microfabrication layouts with focus on challenges like the heatsinking of each pixel of the detector and the overhanging absorbers. The maXs-20 detector is a linear 1x8-pixel array with excellent linearity in its designated energy range up to 20 keV and unsurpassed energy resolution of 1.6 eV for 6 keV x-rays. MaXs-20 operated in a highly portable pulse tube cooled ADR setup has already been used at the EBIT facilities of the MPI-K for new reference measurements of V-like and Ti-like tungsten. The maXs-30 detector currently in development is a 8x8-pixel 2d-array with an active detection area of 16 mm{sup 2} and is designed to detect X-rays up to 50 keV with a designated energy resolution below 5 eV. MaXs-30 will be operated in a cryogen free 3He/4He-dilution refrigerator at the tip of a 40 cm long cold finger at T=20 mK.

  12. New developments in high pressure x-ray spectroscopy beamline at High Pressure Collaborative Access Team.

    Science.gov (United States)

    Xiao, Y M; Chow, P; Boman, G; Bai, L G; Rod, E; Bommannavar, A; Kenney-Benson, C; Sinogeikin, S; Shen, G Y

    2015-07-01

    The 16 ID-D (Insertion Device - D station) beamline of the High Pressure Collaborative Access Team at the Advanced Photon Source is dedicated to high pressure research using X-ray spectroscopy techniques typically integrated with diamond anvil cells. The beamline provides X-rays of 4.5-37 keV, and current available techniques include X-ray emission spectroscopy, inelastic X-ray scattering, and nuclear resonant scattering. The recent developments include a canted undulator upgrade, 17-element analyzer array for inelastic X-ray scattering, and an emission spectrometer using a polycapillary half-lens. Recent development projects and future prospects are also discussed.

  13. Probing stellar winds and accretion physics in high-mass X-ray binaries and ultra-luminous X-ray sources with LOFT

    OpenAIRE

    Orlandini, M.; Doroshenko, V.; Zampieri, L.; Bozzo, E.; Baykal, A.; Blay, P.; Chernyakova, M.; Corbet, R.; D'Aì, A.; Enoto, T.; Ferrigno, C.; Finger, M.; Klochkov, D.; Kreykenbohm, I.; Inam, S. C.

    2015-01-01

    This is a White Paper in support of the mission concept of the Large Observatory for X-ray Timing (LOFT), proposed as a medium-sized ESA mission. We discuss the potential of LOFT for the study of high-mass X-ray binaries and ultra-luminous X-ray sources. For a summary, we refer to the paper.

  14. Line focus x-ray tubes—a new concept to produce high brilliance x-rays

    Science.gov (United States)

    Bartzsch, Stefan; Oelfke, Uwe

    2017-11-01

    Currently hard coherent x-ray radiation at high photon fluxes can only be produced with large and expensive radiation sources, such as 3rd generation synchrotrons. Especially in medicine, this limitation prevents various promising developments in imaging and therapy from being translated into clinical practice. Here we present a new concept of highly brilliant x-ray sources, line focus x-ray tubes (LFXTs), which may serve as a powerful and cheap alternative to synchrotrons and a range of other existing technologies. LFXTs employ an extremely thin focal spot and a rapidly rotating target for the electron beam which causes a change in the physical mechanism of target heating, allowing higher electron beam intensities at the focal spot. Monte Carlo simulations and numeric solutions of the heat equation are used to predict the characteristics of the LFXT. In terms of photon flux and coherence length, the performance of the line focus x-ray tube compares with inverse Compton scattering sources. Dose rates of up to 180 Gy s-1 can be reached in 50 cm distance from the focal spot. The results demonstrate that the line focus tube can serve as a powerful compact source for phase contrast imaging and microbeam radiation therapy. The production of a prototype seems technically feasible.

  15. 21 CFR 892.1700 - Diagnostic x-ray high voltage generator.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Diagnostic x-ray high voltage generator. 892.1700... (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1700 Diagnostic x-ray high voltage generator. (a) Identification. A diagnostic x-ray high voltage generator is a device that is intended to...

  16. High efficiency, multiterawatt x-ray free electron lasers

    Directory of Open Access Journals (Sweden)

    C. Emma

    2016-02-01

    Full Text Available In this paper we present undulator magnet tapering methods for obtaining high efficiency and multiterawatt peak powers in x-ray free electron lasers (XFELs, a key requirement for enabling 3D atomic resolution single molecule imaging and nonlinear x-ray science. The peak power and efficiency of tapered XFELs is sensitive to time dependent effects, like synchrotron sideband growth. To analyze this dependence in detail we perform a comparative numerical optimization for the undulator magnetic field tapering profile including and intentionally disabling these effects. We show that the solution for the magnetic field taper profile obtained from time independent optimization does not yield the highest extraction efficiency when time dependent effects are included. Our comparative optimization is performed for a novel undulator designed specifically to obtain TW power x-ray pulses in the shortest distance: superconducting, helical, with short period and built-in strong focusing. This design reduces the length of the breaks between modules, decreasing diffraction effects, and allows using a stronger transverse electron focusing. Both effects reduce the gain length and the overall undulator length. We determine that after a fully time dependent optimization of a 100 m long Linac coherent light source-like XFEL we can obtain a maximum efficiency of 7%, corresponding to 3.7 TW peak radiation power. Possible methods to suppress the synchrotron sidebands, and further enhance the FEL peak power, up to about 6 TW by increasing the seed power and reducing the electron beam energy spread, are also discussed.

  17. Highly magnetic Co nanoparticles fabricated by X-ray radiolysis

    Science.gov (United States)

    Clifford, Dustin M.; Castano, Carlos E.; Rojas, Jessika V.

    2018-03-01

    Advanced routes for the synthesis of nanomaterials, such as ferromagnetic nanoparticles, are being explored that are easy to perform using cost-effective and non-toxic precursors. Radiolytic syntheses based on the use of X-rays as ionizing radiation are promising towards this effort. X-rays were used to produce highly magnetic cobalt nanoparticles (NPs), stable in air up to 200 °C, from the radiolysis of water. Crystal structure analysis by XRD indicates a mixture of Cofcc, 63%, and Cohcp, 37%, phases. Magnetic analysis by VSM gave a saturation magnetization (Ms) 136 emu/g at 1 T and coercivity (Hc) = 325 Oe when the reaction solution was purged with N2 while an air-purged treatment resulted in Co NPs having 102 emu/g with a coercivity (Hc) 270 Oe. Overall, the reduction of Co2+ occurred in an aqueous reaction environment without addition of chemical reductants resulting in Co NPs with size distribution from 20 to 140 nm. This clean approach at ambient temperature produced highly magnetic Co NPs that may be used for switching devices (i.e. reed switches) or as additives for alloys that require high Curie points.

  18. Catalogue of high-mass X-ray binaries in the Galaxy (4th edition)

    NARCIS (Netherlands)

    Liu, Q.Z.; van Paradijs, J.; van den Heuvel, E.P.J.

    2006-01-01

    We present a new edition of the catalogue of high-mass X-ray binaries in the Galaxy. The catalogue contains source name(s), coordinates, finding chart, X-ray luminosity, system parameters, and stellar parameters of the components and other characteristic properties of 114 high-mass X-ray binaries,

  19. Workshop on high heat load x-ray optics

    Energy Technology Data Exchange (ETDEWEB)

    1990-01-01

    A workshop on High Heat Load X-Ray Optics'' was held at Argonne National Laboratory on August 3--5, 1989. The object of this workshop was to discuss recent advances in the art of cooling x-ray optics subject to high heat loads from synchrotron beams. The cooling of the first optical element in the intense photon beams that will be produced in the next generation of synchrotron sources is recognized as one of the major challenges that must be faced before one will be able to use these very intense beams in future synchrotron experiments. Considerable advances have been made in this art during the last few years, but much work remains to be done before the heating problem can be said to be completely solved. Special emphasis was placed on recent cooling experiments and detailed finite element'' and finite difference'' calculations comparing experiment with theory and extending theory to optimize performance.

  20. Characterization of ceramic archaeological by high resolution X ray microtomography

    Energy Technology Data Exchange (ETDEWEB)

    Machado, Alessandra C.; Freitas, Renato; Calza, Cristiane F.; Lopes, Ricardo T.; Lima, Inaya, E-mail: alecastro@lin.ufrj.br [Coordenacao dos Programas de Pos-Graduacao de Engenharia (COPPE/UFRJ), Rio de Janeiro, RJ (Brazil). Lab. de Instrumentacao Nuclear; Carvalho, Daniele D.; Gaspar, Maria D. [Museu Nacional (MN/UFRJ), RJ (Brazil). Centro de Tecnologia

    2013-07-01

    Characterization of ceramic fragments is a very important area of research in art and archeometry area because it enables a greater understanding of how ancient civilizations behave and what were their traditions and customs. Petrography and chemical analyses are commonly used, but these techniques are destructive, which is not interesting for this type of sample. Through the exchange of multidisciplinary scientific knowledge and new partnerships, high resolution X-ray microtomography has been introduced in archaeological area as a great possibility of 3D inspection in a non-destructive way. The goal of this work is to investigate the internal microstructures of four samples of archeological ceramic, from the Archaeological Site of Macacu - RJ. The X-ray microtomography were performed in a high resolution setup, and can be used to infer the nature of organic temper even with all plant remains completely burnt out during the firing process and also to ensure the homogeneity of samples envisaged for geochemical analyses, especially with respect to the distribution of chemically diverse fabric compounds. In this way this study intends to contribute to our understanding of the archaeological and historical formations of this region. (author)

  1. Semi-automated scoring of pulmonary emphysema from X-ray CT: Trainee reproducibility and accuracy

    Energy Technology Data Exchange (ETDEWEB)

    Owrangi, Amir M., E-mail: aowrangi@robarts.ca [Imaging Research Laboratories, Robarts Research Institute, London (Canada); Entwistle, Brandon, E-mail: Brandon.Entwistle@londonhospitals.ca; Lu, Andrew, E-mail: Andrew.Lu@londonhospitals.ca; Chiu, Jack, E-mail: Jack.Chiu@londonhospitals.ca; Hussain, Nabil, E-mail: Nabil.Hussain@londonhospitals.ca; Etemad-Rezai, Roya, E-mail: Roya.EtemadRezai@lhsc.on.ca; Parraga, Grace, E-mail: gparraga@robarts.ca [Imaging Research Laboratories, Robarts Research Institute, London (Canada); Graduate Program in Biomedical Engineering, Department of Medical Imaging, Department of Medical Biophysics, The University of Western Ontario, London (Canada)

    2013-11-01

    Objective: We developed a semi-automated tool to quantify emphysema from thoracic X-ray multi-detector (64-slice) computed tomography (CT) for training purposes and multi-reader studies. Materials and Methods: Thoracic X-ray CT was acquired in 93 ex-smokers, who were evaluated by six trainees with little or no expertise (trainees) and a single experienced thoracic radiologist (expert). A graphic user interface (GUI) was developed for emphysema quantification based on the percentile of lung where a score of 0 = no abnormalities, 1 = 1–25%, 2 = 26–50%, 3 = 51–75% and 4 = 76–100% for each lung side/slice. Trainees blinded to subject characteristics scored randomized images twice; accuracy was determined by comparison to expert scores, density histogram 15th percentile (HU{sub 15}), relative area at −950 HU (RA{sub 950}), low attenuation clusters at −950 HU (LAC{sub 950}), −856 HU (LAC{sub 856}) and the diffusing capacity for carbon monoxide (DL{sub CO%pred}). Intra- and inter-observer reproducibility was evaluated using coefficients-of-variation (COV), intra-class (ICC) and Pearson correlations. Results: Trainee–expert correlations were significant (r = 0.85–0.97, p < 0.0001) and a significant trainee bias (0.15 ± 0.22) was observed. Emphysema score was correlated with RA{sub 950} (r = 0.88, p < 0.0001), HU{sub 15} (r = −0.77, p < 0.0001), LAC{sub 950} (r = 0.76, p < 0.0001), LAC{sub 856} (r = 0.74, p = 0.0001) and DL{sub CO%pred} (r = −0.71, p < 0.0001). Intra-observer reproducibility (COV = 4–27%; ICC = 0.75–0.94) was moderate to high for trainees; intra- and inter-observer COV were negatively and non-linearly correlated with emphysema score. Conclusion: We developed a GUI for rapid and interactive emphysema scoring that allows for comparison of multiple readers with clinical and radiological standards.

  2. X-ray Diffraction Study of Arsenopyrite at High Pressure

    Energy Technology Data Exchange (ETDEWEB)

    D Fan; M Ma; W Zhou; S Wei; Z Chen; H Xie

    2011-12-31

    The high-pressure X-ray diffraction study of a natural arsenopyrite was investigated up to 28.2 GPa using in situ angle-dispersive X-ray diffraction and a diamond anvil cell at National Synchrotron Light Source, Brookhaven National Laboratory. The 16:3:1 methanol-ethanol-water mixture was used as a pressure-transmitting medium. Pressures were measured using the ruby-fluorescence method. No phase change has been observed up to 28.2 GPa. The isothermal equation of state (EOS) was determined. The values of K{sub 0}, and K'{sub 0} refined with a third-order Birch-Murnaghan EOS are K{sub 0} = 123(9) GPa, and K'{sub 0} = 5.2(8). Furthermore, we confirm that the linear compressibilities ({beta}) along a, b and c directions of arsenopyrite is elastically isotropic ({beta}{sub a} = 6.82 x 10{sup -4}, {beta}{sub b} = 6.17 x 10{sup -4} and {beta}{sub c} = 6.57 x 10{sup -4} GPa{sup -1}).

  3. Accretion in supergiant High Mass X-ray Binaries

    Directory of Open Access Journals (Sweden)

    Manousakis Antonios

    2014-01-01

    Full Text Available Supergiant High Mass X-ray Binary systems (sgHMXBs consist of a massive, late type, star and a neutron star. The massive stars exhibits strong, radiatively driven, stellar winds. Wind accretion onto compact object triggers X-ray emission, which alters the stellar wind significantly. Hydrodynamic simulation has been used to study the neutron star - stellar wind interaction it two sgHMXBs: i A heavily obscured sgHMXB (IGR J17252–3616 discovered by INTEGRAL. To account for observable quantities (i.e., absorbing column density we have to assume a very slow wind terminal velocity of about 500 km/s and a rather massive neutron star. If confirmed in other obscured systems, this could provide a completely new stellar wind diagnostics. ii A classical sgHMXB (Vela X-1 has been studied in depth to understand the origin of the off-states observed in this system. Among many models used to account for this observed behavior (clumpy wind, gating mechanism we propose that self-organized criticality of the accretion stream is the likely reason for the observed behavior. In conclusion, the neutron star, in these two examples, acts very effciently as a probe to study stellar winds.

  4. 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)

  5. X-RAY ABSORPTION OF HIGH-REDSHIFT QUASARS

    Energy Technology Data Exchange (ETDEWEB)

    Eitan, Assaf; Behar, Ehud, E-mail: sassafe@tx.technion.ac.il, E-mail: behar@physics.technion.ac.il [Physics Department, Technion, Haifa 32000 (Israel)

    2013-09-01

    The soft X-ray photoelectric absorption of high-z quasars has been known for two decades, but has no unambiguous astrophysical context. We construct the largest sample to date of 58 high-redshift quasars (z > 0.45) selected from the XMM-Newton archive based on a high photon count criterion (>1800). We measure the optical depth {tau} at 0.5 keV and find that 43% of the quasars show significant absorption. We aim to find which physical parameters of the quasars, e.g., redshift, radio luminosity, radio loudness, or X-ray luminosity, drive their observed absorption. We compare the absorption behavior with redshift with the pattern expected if the diffuse intergalactic medium (IGM) is responsible for the observed absorption. We also compare the absorption with a comparison sample of gamma-ray burst (GRB) X-ray afterglows. Although the z > 2 quasar opacity is consistent with diffuse IGM absorption, many intermediate-z (0.45 < z < 2) quasars are not sufficiently absorbed for this scenario, and are appreciably less absorbed than GRBs. Only 10/37 quasars at z < 2 are absorbed, and only 5/30 radio-quiet quasars are absorbed. We find a weak correlation between {tau} and z, and an even weaker correlation between {tau} and radio luminosity. These findings lead to the conclusion that although a diffuse IGM origin for the quasar absorption is unlikely, the optical depth does seem to increase with redshift, roughly as (1 + z){sup 2.2{+-}0.6}, tending to {tau} Almost-Equal-To 0.4 at high redshifts, similar to the high-z GRBs. This result can be explained by an ionized and clumpy IGM at z < 2, and a cold, diffuse IGM at higher redshift. If, conversely, the absorption occurs at the quasar, and owing to the steep L{sub x} {proportional_to}(1 + z){sup 7.1{+-}0.5} correlation in the present sample, the host column density scales as N{sub H}{proportional_to}L{sub x}{sup 0.7{+-}0.1}.

  6. Fabricating High-Resolution X-Ray Collimators

    Science.gov (United States)

    Appleby, Michael; Atkinson, James E.; Fraser, Iain; Klinger, Jill

    2008-01-01

    A process and method for fabricating multi-grid, high-resolution rotating modulation collimators for arcsecond and sub-arcsecond x-ray and gamma-ray imaging involves photochemical machining and precision stack lamination. The special fixturing and etching techniques that have been developed are used for the fabrication of multiple high-resolution grids on a single array substrate. This technology has application in solar and astrophysics and in a number of medical imaging applications including mammography, computed tomography (CT), single photon emission computed tomography (SPECT), and gamma cameras used in nuclear medicine. This collimator improvement can also be used in non-destructive testing, hydrodynamic weapons testing, and microbeam radiation therapy.

  7. X-ray emission from high temperature plasmas

    Science.gov (United States)

    Harries, W. L.

    1974-01-01

    X-rays from a 25-hJ plasma focus apparatus were observed with pinhole cameras. The cameras consist of 0.4 mm diameter pinholes in 2 cm thick lead housing enclosing an X-ray intensifying screen at the image plane. Pictures recorded through thin aluminum foils or plastic sheets for X-ray energies sub gamma smaller than 15 keV show distributed X-ray emissions from the focussed plasma and from the anode surface. However, when thick absorbers are used, radial filamentary structure in the X-ray emission from the anode surface is revealed. Occasionally larger structures are observed in addition to the filaments. Possible mechanisms for the filamentary structure are discussed.

  8. High energy X-ray phase and dark-field imaging using a random absorption mask.

    Science.gov (United States)

    Wang, Hongchang; Kashyap, Yogesh; Cai, Biao; Sawhney, Kawal

    2016-07-28

    High energy X-ray imaging has unique advantage over conventional X-ray imaging, since it enables higher penetration into materials with significantly reduced radiation damage. However, the absorption contrast in high energy region is considerably low due to the reduced X-ray absorption cross section for most materials. Even though the X-ray phase and dark-field imaging techniques can provide substantially increased contrast and complementary information, fabricating dedicated optics for high energies still remain a challenge. To address this issue, we present an alternative X-ray imaging approach to produce transmission, phase and scattering signals at high X-ray energies by using a random absorption mask. Importantly, in addition to the synchrotron radiation source, this approach has been demonstrated for practical imaging application with a laboratory-based microfocus X-ray source. This new imaging method could be potentially useful for studying thick samples or heavy materials for advanced research in materials science.

  9. Determination of the weld thickness of turbine for aircraft engine by high-energy X-ray tomography

    Directory of Open Access Journals (Sweden)

    Zhong Yang

    2017-01-01

    Full Text Available It is necessary to test the weld thickness of turbine, as it is one of the most important parts for aircraft engine. The weld thickness of turbine for aircraft engine by high-energy X-ray tomography was determined. We used an X-ray tube and a betatron as X-ray sources. The wall thickness of two tubes and weld thickness of turbine were measured. It is shown that the high-energy X-ray tomography system is determined the wall thickness of the tube and the weld thickness of turbine with high accuracy. We also studied the method to reduce scattered radiation. All experiments were carried out in the non-destructive testing (NDT Institute of Tomsk Polytechnic University (TPU.

  10. High-Energy X-Ray Diffraction Analysis Tool

    Energy Technology Data Exchange (ETDEWEB)

    2011-11-29

    The functionality of heRXD includes the following: distance and angular calibration and viewing flat-panel detector images used for X-ray diffraction; image (polar) rebinning or "caking"; line position fitting in powder diffraction images; image segmentation or "blob finding"; crystal orentation indesing; and lattice vector refinement. These functionalities encompass a critical set analyzing teh data for high-energy diffraction measurements that are currently performed at synchrotron sources such as the Advanced Photon Source (APS). The software design modular and open source under LGPL. The intent is to provide a common framework and graphical user interface that has the ability to utillize internal as well as external subroutines to provide various optins for performing the fuctionalities listed above. The software will initially be deployed at several national user facilities--including APS, ALS, and CHESS--and then made available for download using a hosting service such as sourceforge.

  11. High temperature x-ray micro-tomography

    Energy Technology Data Exchange (ETDEWEB)

    MacDowell, Alastair A., E-mail: aamacdowell@lbl.gov; Barnard, Harold; Parkinson, Dilworth Y.; Gludovatz, Bernd [Lawrence Berkeley National Lab., Berkeley, CA 94720 (United States); Haboub, Abdel [Lawrence Berkeley National Lab., Berkeley, CA 94720 (United States); current –Lincoln Univ., Jefferson City, Missouri, 65101 (United States); Larson, Natalie; Zok, Frank [University California Santa Barbara, Santa Barbara CA 93106 (United States); Panerai, Francesco; Mansour, Nagi N. [NASA Ames Research Centre, Moffett Field, CA, 94035 (United States); Bale, Hrishikesh [University California Berkeley, Berkeley, CA 94720 (United States); current - Carl Zeiss X-ray Microscopy, 4385 Hopyard Rd #100, Pleasanton, CA 94588 (United States); Acevedo, Claire [Lawrence Berkeley National Lab., Berkeley, CA 94720 (United States); University California San Francisco, San Francisco, CA 94143 (United States); Liu, Dong [University of Bristol, Bristol BS8 1TH (United Kingdom); Ritchie, Robert O. [Lawrence Berkeley National Lab., Berkeley, CA 94720 (United States); University California Berkeley, Berkeley, CA 94720 (United States)

    2016-07-27

    There is increasing demand for 3D micro-scale time-resolved imaging of samples in realistic - and in many cases extreme environments. The data is used to understand material response, validate and refine computational models which, in turn, can be used to reduce development time for new materials and processes. Here we present the results of high temperature experiments carried out at the x-ray micro-tomography beamline 8.3.2 at the Advanced Light Source. The themes involve material failure and processing at temperatures up to 1750°C. The experimental configurations required to achieve the requisite conditions for imaging are described, with examples of ceramic matrix composites, spacecraft ablative heat shields and nuclear reactor core Gilsocarbon graphite.

  12. Copper L X-ray spectra measured by a high resolution ion-induced X-ray spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, Ryohei; Hamaguchi, Dai; Kageyama, Hiroyoshi [Kyoto Inst. of Tech. (Japan)] [and others

    1997-03-01

    High resolution L X-ray emission spectra of Cu have been measured by 0.75 MeV/u H, He, and F, 0.73 MeV/u Ar, 0.64 MeV/u Si, and 0.073 MeV/u Si ion impacts with a crystal spectrometer. The X-ray transition energies in the Cu target for L{iota}, L{eta}, L{alpha}{sub 1,2}, L{beta}{sub 1}, and L{beta}{sub 3,4} diagram lines induced by light ion impacts are determined, which are in good agreement with those given in the reference. The difference in L X-ray emission spectra produced by H, He, F, Si, and Ar ions are considered and the L{alpha}{sub 1,2} and L{beta}{sub 1} emission spectra are compared with the calculated ones based on the multiconfiguration Dirac-Fock method. (author)

  13. High Brightness Electron Gun for X-Ray Source

    CERN Document Server

    Ohsawa, Satoshi; Ikeda, Mitsuo; Kanno, K; Sugimura, Takashi; Tawada, Masafumi

    2005-01-01

    A new electron-gun system is under development in order to increase X-ray from a rotating target. In commercial X-ray sources electron beams usually hit targets at the outer part. Owing to deformation by centrifugal force, there has been a limit on electron beam intensities. In order to overcome this difficulty, we adopted a new injection system which strikes inside of a ring-shape projection on a rotating target. It has an advantage in that heated-up points have supports back side against centrifugal force. This merit allows us to raise electron beam to give stronger X-rays.

  14. Comprehensive x-ray spectral code for high energy astrophysics

    Energy Technology Data Exchange (ETDEWEB)

    Liedahl, D A; Fournier, K B; Mauche, C W

    2000-08-18

    The aim of this project has been to develop a spectral analysis tool with a level of quality and completeness commensurate to that expected in data from the current generation of X-ray observatories. The code is called LXSS (Livermore X-Ray Spectral Synthesizer). X-ray-emitting astrophysical plasmas are rarely, if ever, in LTE, so they have adopted the detailed level accounting approach, in which rates for processes that populate or depopulate atomic energy levels are treated explicitly. This entails the generation of a large quantity of atomic data, most of which is calculated using ''in-house'' computer codes. Calculations are benchmarked against laboratory data, and spectral models have been used to provide first-time interpretations of astrophysical X-ray spectra. The design of a versatile graphical user interface that allows access to and manipulation of the atomic database comprises the second major part of the project.

  15. Gas scintillation glass GEM detector for high-resolution X-ray imaging and CT

    Energy Technology Data Exchange (ETDEWEB)

    Fujiwara, T., E-mail: fujiwara-t@aist.go.jp [Research Institute for Measurement and Analytical Instrumentation, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8568 (Japan); Mitsuya, Y. [Nuclear Professional School, The University of Tokyo, Tokai, Naka, Ibaraki 319-1188 (Japan); Fushie, T. [Radiment Lab. Inc., Setagaya, Tokyo 156-0044 (Japan); Murata, K.; Kawamura, A.; Koishikawa, A. [XIT Co., Naruse, Machida, Tokyo 194-0045 (Japan); Toyokawa, H. [Research Institute for Measurement and Analytical Instrumentation, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8568 (Japan); Takahashi, H. [Institute of Engineering Innovation, School of Engineering, The University of Tokyo, Bunkyo, Tokyo 113-8654 (Japan)

    2017-04-01

    A high-spatial-resolution X-ray-imaging gaseous detector has been developed with a single high-gas-gain glass gas electron multiplier (G-GEM), scintillation gas, and optical camera. High-resolution X-ray imaging of soft elements is performed with a spatial resolution of 281 µm rms and an effective area of 100×100 mm. In addition, high-resolution X-ray 3D computed tomography (CT) is successfully demonstrated with the gaseous detector. It shows high sensitivity to low-energy X-rays, which results in high-contrast radiographs of objects containing elements with low atomic numbers. In addition, the high yield of scintillation light enables fast X-ray imaging, which is an advantage for constructing CT images with low-energy X-rays.

  16. A new X-ray pinhole camera for energy dispersive X-ray fluorescence imaging with high-energy and high-spatial resolution

    Energy Technology Data Exchange (ETDEWEB)

    Romano, F.P., E-mail: romanop@lns.infn.it [IBAM, CNR, Via Biblioteca 4, 95124 Catania (Italy); INFN-LNS, Via S. Sofia 62, 95123 Catania (Italy); Altana, C. [INFN-LNS, Via S. Sofia 62, 95123 Catania (Italy); Dipartimento di Fisica e Astronomia, Università di Catania, Via S. Sofia 64, 95123 Catania (Italy); Cosentino, L.; Celona, L.; Gammino, S.; Mascali, D. [INFN-LNS, Via S. Sofia 62, 95123 Catania (Italy); Pappalardo, L. [IBAM, CNR, Via Biblioteca 4, 95124 Catania (Italy); INFN-LNS, Via S. Sofia 62, 95123 Catania (Italy); Rizzo, F. [INFN-LNS, Via S. Sofia 62, 95123 Catania (Italy); Dipartimento di Fisica e Astronomia, Università di Catania, Via S. Sofia 64, 95123 Catania (Italy)

    2013-08-01

    A new X-ray pinhole camera for the Energy Dispersive X-ray Fluorescence (ED-XRF) imaging of materials with high-energy and high-spatial resolution, was designed and developed. It consists of a back-illuminated and deep depleted CCD detector (composed of 1024 × 1024 pixels with a lateral size of 13 μm) coupled to a 70 μm laser-drilled pinhole-collimator, positioned between the sample under analysis and the CCD. The X-ray pinhole camera works in a coaxial geometry allowing a wide range of magnification values. The characteristic X-ray fluorescence is induced on the samples by irradiation with an external X-ray tube working at a maximum power of 100 W (50 kV and 2 mA operating conditions). The spectroscopic capabilities of the X-ray pinhole camera were accurately investigated. Energy response and energy calibration of the CCD detector were determined by irradiating pure target-materials emitting characteristic X-rays in the energy working-domain of the system (between 3 keV and 30 keV). Measurements were performed by using a multi-frame acquisition in single-photon counting. The characteristic X-ray spectra were obtained by an automated processing of the acquired images. The energy resolution measured at the Fe–Kα line is 157 eV. The use of the X-ray pinhole camera for the 2D resolved elemental analysis was investigated by using reference-patterns of different materials and geometries. The possibility of the elemental mapping of samples up to an area of 3 × 3 cm{sup 2} was demonstrated. Finally, the spatial resolution of the pinhole camera was measured by analyzing the profile function of a sharp-edge. The spatial resolution determined at the magnification values of 3.2 × and 0.8 × (used as testing values) is about 90 μm and 190 μm respectively. - Highlights: • We developed an X-ray pinhole camera for the 2D X-ray fluorescence imaging. • X-ray spectra are obtained by a multi-frame acquisition in single photon mode. • The energy resolution in the X-ray

  17. High-contrast x-ray microtomography in dental research

    Science.gov (United States)

    Davis, Graham; Mills, David

    2017-09-01

    X-ray microtomography (XMT) is a well-established technique in dental research. The technique has been used extensively to explore the complex morphology of the root canal system, and to qualitatively and quantitatively evaluate root canal instrumentation and filling efficacy in extracted teeth; enabling different techniques to be compared. Densitometric information can be used to identify and map demineralized tissue resulting from tooth decay (caries) and, in extracted teeth, the method can be used to evaluate different methods of excavation. More recently, high contrast XMT is being used to investigate the relationship between external insults to teeth and the pulpal reaction. When such insults occur, fluid may flow through dentinal tubules as a result of cracking or porosity in enamel. Over time, there is an increase in mineralization along the paths of the tubules from the pulp to the damaged region in enamel and this can be visualized using high contrast XMT. The scanner used for this employs time-delay integration to minimize the effects of detector inhomogeneity in order to greatly increase the upper limit on signal-to-noise ratio that can be achieved with long exposure times. When enamel cracks are present in extracted teeth, the presence of these pathways indicates that the cracking occurred prior to extraction. At high contrast, growth lines are occasionally seen in deciduous teeth which may have resulted from periods of maternal illness. Various other anomalies in mineralization resulting from trauma or genetic abnormalities can also be investigated using this technique.

  18. High Spectral Resolution, High Cadence, Imaging X-ray Microcalorimeters for Solar Physics - Phase 2 Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Microcalorimeter x-ray instruments are non-dispersive, high spectral resolution, broad-band, high cadence imaging spectrometers. We have been developing these...

  19. A compact high vacuum heating chamber for in-situ x-ray scattering studies

    Energy Technology Data Exchange (ETDEWEB)

    Bertram, F.; Deiter, C.; Pflaum, K.; Seeck, O. H. [Hamburger Synchrotronstrahlungslabor am Deutschen Elektronen-Synchrotron, Notkestr. 85, 22607 Hamburg (Germany)

    2012-08-15

    A very compact multi purpose high vacuum heating chamber for x-ray scattering techniques was developed. The compact design allows the chamber to be installed on high precision diffractometers which usually cannot support heavy and/or large equipment. The chamber is covered by a Be dome allowing full access to the hemisphere above the sample which is required for in-plane grazing incident x-ray diffraction and out-off plane wide angle x-ray diffraction.

  20. High-Frequency X-ray Variability Detection in A Black Hole Transient with USA.

    Energy Technology Data Exchange (ETDEWEB)

    Shabad, Gayane

    2000-10-16

    Studies of high-frequency variability (above {approx}100 Hz) in X-ray binaries provide a unique opportunity to explore the fundamental physics of spacetime and matter, since the orbital timescale on the order of several milliseconds is a timescale of the motion of matter through the region located in close proximity to a compact stellar object. The detection of weak high-frequency signals in X-ray binaries depends on how well we understand the level of Poisson noise due to the photon counting statistics, i.e. how well we can understand and model the detector deadtime and other instrumental systematic effects. We describe the preflight timing calibration work performed on the Unconventional Stellar Aspect (USA) X-ray detector to study deadtime and timing issues. We developed a Monte Carlo deadtime model and deadtime correction methods for the USA experiment. The instrumental noise power spectrum can be estimated within {approx}0.1% accuracy in the case when no energy-dependent instrumental effect is present. We also developed correction techniques to account for an energy-dependent instrumental effect. The developed methods were successfully tested on USA Cas A and Cygnus X-1 data. This work allowed us to make a detection of a weak signal in a black hole candidate (BHC) transient.

  1. High-resolution 3D translation measurements using point source x-ray stereoscopy

    Science.gov (United States)

    Salih, Wasil H. M.; Soons, Joris A. M.; Dirckx, Joris J. J.

    2011-02-01

    A method for high-resolution measurement of 3D coordinates and translations of small objects is presented, using single x-ray point-source stereoscopy. The theory of the pinhole method is re-derived for a point-source x-ray projection setup using a conical beam. The method is then implemented using a micro x-ray tomography setup with a single 8 µm point source. Stereo projections are obtained by rotating the object over 90° between subsequent recordings, and microscopic tungsten beads are used as marker points. The accuracy of the method is tested on a spherical calibration object, and found to be better than 10 µm. Using a translation stage, the measurement uncertainty for translation measurements was found to be better than 5 µm along both axes parallel to the detector and at right angles to the detector. Due to the short measurement time and the high resolution, the method will be useful to study the biomechanics of small specimens, and the principle of the method is useful in any cone-beam-based setup.

  2. Next Generation Astronomical X-ray Optics: High Angular Resolution, Light Weight, and Low Production Cost

    Science.gov (United States)

    Zhang. W. W.; Biskach, M. P.; Blake, P. N.; Chan, K. W.; Gaskin, J. A.; Hong, M. L.; Jones, W. D.; Kolos, L. D.; Mazzarella, J. R.; McClelland, R. S.; hide

    2012-01-01

    X-ray astronomy depends on the availability of telescopes with high resolution and large photon collecting areas. Since x-ray observation can only be carried out above the atmosphere, these telescopes must be necessarily lightweight. Compounding the lightweight requirement is that an x-ray telescope consists of many nested concentric shells, which further require that x-ray mirrors must also be geometrically thin to achieve high packing efficiency. This double lightweight and geometrically thin requirement poses significant technical challenges in fabricating the mirrors and in integrating them into mirror assemblies. This paper reports on the approach, strategy and status of our x-ray optics development program whose objective is to meet these technical challenges at modest cost to enable future x-ray missions, including small Explorer missions in the near term, probe class missions in the medium term, and large flagship missions in the long term.

  3. 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

  4. Nanofabrication and characterization of high-line-density x-ray transmission gratings

    DEFF Research Database (Denmark)

    Zhu, Xiaoli; Li, Hailiang; Cao, Leifeng

    2017-01-01

    We report the nanofabrication and characterization of x-ray transmission gratings with a high aspect ratio and a feature size of down to 65 nm. Two nanofabrication methods, the combination of electron beam and optical lithography and the combination of electron beam, x-ray, and optical lithograph...... the development of x-ray diffractive optical elements. (C) 2017 Society of Photo-Optical Instrumentation Engineers (SPIE)...

  5. Johann Spectrometer for High Resolution X-ray Spectroscopy

    Science.gov (United States)

    Machek, Pavel; Welter, Edmund; Caliebe, Wolfgang; Brüggmann, Ulf; Dräger, Günter; Fröba, Michael

    2007-01-01

    A newly designed vacuum Johann spectrometer with a large focusing analyzer crystal for inelastic x-ray scattering and high resolution fluorescence spectroscopy has been installed at the DORIS III storage ring. Spherically bent crystals with a maximum diameter of 125 mm, and cylindrically bent crystals are employed as dispersive optical elements. Standard radius of curvature of the crystals is 1000 mm, however, the design of the mechanical components also facilitates measurements with smaller and larger bending radii. Up to four crystals are mounted on a revolving crystal changer which enables crystal changes without breaking the vacuum. The spectrometer works at fixed Bragg angle. It is preferably designed for the measurements in non-scanning mode with a broad beam spot, and offers a large flexibility to set the sample to the optimum position inside the Rowland circle. A deep depletion CCD camera is employed as a position sensitive detector to collect the energy-analyzed photons on the circumference of the Rowland circle. The vacuum in the spectrometer tank is typically 10-6 mbar. The sample chamber is separated from the tank either by 25 μm thick Kapton windows, which allows samples to be measured under ambient conditions, or by two gate valves. The spectrometer is currently installed at wiggler beamline W1 whose working range is 4-10.5 keV with typical flux at the sample of 5×1010photons/s/mm2. The capabilities of the spectrometer are illustrated by resonant inelastic experiments on 3d transition metals and rare earth compounds, and by chemical shift measurements on chromium compounds.

  6. Plasma instability control toward high fluence, high energy x-ray continuum source

    Science.gov (United States)

    Poole, Patrick; Kirkwood, Robert; Wilks, Scott; Blue, Brent

    2017-10-01

    X-ray source development at Omega and NIF seeks to produce powerful radiation with high conversion efficiency for material effects studies in extreme fluence environments. While current K-shell emission sources can achieve tens of kJ on NIF up to 22 keV, the conversion efficiency drops rapidly for higher Z K-alpha energies. Pulsed power devices are efficient generators of MeV bremsstrahlung x-rays but are unable to produce lower energy photons in isolation, and so a capability gap exists for high fluence x-rays in the 30 - 100 keV range. A continuum source under development utilizes instabilities like Stimulated Raman Scattering (SRS) to generate plasma waves that accelerate electrons into high-Z converter walls. Optimizing instabilities using existing knowledge on their elimination will allow sufficiently hot and high yield electron distributions to create a superior bremsstrahlung x-ray source. An Omega experiment has been performed to investigate the optimization of SRS and high energy x-rays using Au hohlraums with parylene inner lining and foam fills, producing 10× greater x-ray yield at 50 keV than conventional direct drive experiments on the facility. Experiment and simulation details on this campaign will be presented. This work was performed under the auspices of the US DoE by LLNL under Contract No. DE-AC52-07NA27344.

  7. A versatile, highly-efficient, high-resolution von Hamos Bragg crystal x-ray spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Vane, C.R.; Smith, M.S.; Raman, S.

    1988-01-01

    An efficient, high-resolution, vertical-focusing, Bragg crystal x-ray spectrometer has been specifically designed and constructed for use in measurements of x rays produced in collisions of energetic heavy ions. In this report the design and resulting operational characteristics of the final instrument are fully described. A wide variety of sample data is also included to illustrate the utility of this device in several areas of research. 14 refs., 38 figs.

  8. Towards phasing using high X-ray intensity

    Directory of Open Access Journals (Sweden)

    Lorenzo Galli

    2015-11-01

    Full Text Available X-ray free-electron lasers (XFELs show great promise for macromolecular structure determination from sub-micrometre-sized crystals, using the emerging method of serial femtosecond crystallography. The extreme brightness of the XFEL radiation can multiply ionize most, if not all, atoms in a protein, causing their scattering factors to change during the pulse, with a preferential `bleaching' of heavy atoms. This paper investigates the effects of electronic damage on experimental data collected from a Gd derivative of lysozyme microcrystals at different X-ray intensities, and the degree of ionization of Gd atoms is quantified from phased difference Fourier maps. A pattern sorting scheme is proposed to maximize the ionization contrast and the way in which the local electronic damage can be used for a new experimental phasing method is discussed.

  9. High quality multilayer mirrors for soft X-rays

    Energy Technology Data Exchange (ETDEWEB)

    Grimmer, H.; Boeni, P.; Breitmeier, U.; Clemens, D.; Horisberger, M. [Paul Scherrer Inst. (PSI), Villigen (Switzerland); Mertins, H.C.; Schaefers, F. [BESSY, Berlin (Germany)

    1997-09-01

    In an effort to develop optical components for X-rays with wavelengths in the water window (2.3 -4.4 nm) multilayer structures have been designed for the following applications: in transmission as phase shifters to change linear into circular polarization, in reflection as mirrors close to normal incidence and as linear polarizers at an angle of incidence of 45{sup o}. (author) 1 fig., 1 tab., 1 ref.

  10. Attenuation of high-energy x rays by iron shielding

    Energy Technology Data Exchange (ETDEWEB)

    Bespalov, V.I.; Chakhlov, V.L.; Shtein, M.M.

    1988-04-01

    Monte Carlo calculations are presented on electron-accelerator x-ray spectra for actual target thicknesses and electron energies of 4-50 MeV. Effective attenuation coefficients have been obtained as well as build-up factors for collimated beams andiron shielding of thickness form 1 to 80 cm. The radiation contrast has been determined as a function of thickness for this energy range.

  11. High energy x-ray reflectivity and scattering study from spectrum-x-gamma flight mirrors

    DEFF Research Database (Denmark)

    Christensen, Finn Erland; Budtz-Jørgensen, Carl; Frederiksen, P. Kk

    1993-01-01

    Line radiation from Fe K-alpha(1), Cu K-alpha(1), and Ag K-alpha(1) is used to study the high energy X-ray reflectivity and scattering behavior of flight-quality X-ray mirrors having various Al substrates. When both the specular and the scattered radiation are integrated, near theoretical...

  12. Discovery of extended X-ray emission around the highly magnetic RRAT J1819-1458

    NARCIS (Netherlands)

    Rea, N.; McLaughlin, M.A.; Gaensler, B.M.; Slane, P.O.; Stella, L.; Reynolds, S.P.; Burgay, M.; Israel, G.L.; Possenti, A.; Chatterjee, S.

    2009-01-01

    We report on the discovery of extended X-ray emission around the high magnetic field rotating radio transient J1819-1458. Using a 30 ks Chandra ACIS-S observation, we found significant evidence for extended X-ray emission with a peculiar shape: a compact region out to similar to 5.'' 5, and more

  13. A high resolution X-ray crystal spectrometer to study electron and ...

    Indian Academy of Sciences (India)

    We have studied fast ion–atom and electron–atom collision processes using a reconditioned high resolution X-ray spectrometer. The X-rays, generated by the collisions, are dispersed by a curved ADP crystal (Johansson geometry) and detected by a gas proportional counter. A self-written LabVIEW based program has ...

  14. The nuclear spectroscopic telescope array (NuSTAR) high-energy X-ray mission

    DEFF Research Database (Denmark)

    Madsen, Kristin K.; Harrison, Fiona A.; Hongjun An

    2014-01-01

    The Nuclear Spectroscopic Telescope Array (NuSTAR) mission was launched on 2012 June 13 and is the first focusing high-energy X-ray telescope in orbit operating above ~10 keV. NuSTAR flies two co-aligned Wolter-I conical approximation X-ray optics, coated with Pt/C and W/Si multilayers...

  15. High power x-ray welding of metal-matrix composites

    Science.gov (United States)

    Rosenberg, Richard A.; Goeppner, George A.; Noonan, John R.; Farrell, William J.; Ma, Qing

    1999-01-01

    A method for joining metal-matrix composites (MMCs) by using high power x-rays as a volumetric heat source is provided. The method involves directing an x-ray to the weld line between two adjacent MMCs materials to create an irradiated region or melt zone. The x-rays have a power density greater than about 10.sup.4 watts/cm.sup.2 and provide the volumetric heat required to join the MMC materials. Importantly, the reinforcing material of the metal-matrix composites remains uniformly distributed in the melt zone, and the strength of the MMCs are not diminished. In an alternate embodiment, high power x-rays are used to provide the volumetric heat required to weld metal elements, including metal elements comprised of metal alloys. In an alternate embodiment, high power x-rays are used to provide the volumetric heat required to weld metal elements, including metal elements comprised of metal alloys.

  16. Ultra-High Vacuum Compatible Optical Chopper System for Synchrotron X-ray Scanning Tunneling Microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Hao; Cummings, Marvin L.; Shirato, Nozomi; Stripe, Benjamin D.; Rosenmann, Daniel; Preissner, Curt A.; Freeland, John W.; Kersell, Heath R.; Hla, Saw Wai; Rose, Volker

    2015-01-01

    High-speed beam choppers are a crucial part of time-resolved x-ray studies as well as a necessary component to enable elemental contrast in synchrotron x-ray scanning tunneling microscopy (SX-STM). However, many chopper systems are not capable of operation in vacuum, which restricts their application to x-ray studies with high photon energies, where air absorption does not present a significant problem. To overcome this limitation, we present a fully ultra-high vacuum (UHV) compatible chopper system capable of operating at variable chopping frequencies up to 4 kHz. The lightweight aluminum chopper disk is coated with Ti and Au films to provide the required beam attenuation for soft and hard x-rays with photon energies up to about 12 keV. The chopper is used for lock-in detection of x-ray enhanced signals in SX-STM.

  17. Ultra-high vacuum compatible optical chopper system for synchrotron x-ray scanning tunneling microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Hao, E-mail: hc000211@ohio.edu [Advanced Photon Source, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439 (United States); Nanoscale and Quantum Phenomena Institute, Physics & Astronomy Department, Ohio University, Athens, Ohio 45701 (United States); Cummings, Marvin; Shirato, Nozomi; Stripe, Benjamin; Preissner, Curt; Freeland, John W. [Advanced Photon Source, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439 (United States); Rosenmann, Daniel [Center for Nanoscale Materials, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439 (United States); Kersell, Heath; Hla, Saw-Wai [Nanoscale and Quantum Phenomena Institute, Physics & Astronomy Department, Ohio University, Athens, Ohio 45701 (United States); Center for Nanoscale Materials, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439 (United States); Rose, Volker, E-mail: vrose@anl.gov [Advanced Photon Source, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439 (United States); Center for Nanoscale Materials, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439 (United States)

    2016-01-28

    High-speed beam choppers are a crucial part of time-resolved x-ray studies as well as a necessary component to enable elemental contrast in synchrotron x-ray scanning tunneling microscopy (SX-STM). However, many chopper systems are not capable of operation in vacuum, which restricts their application to x-ray studies with high photon energies, where air absorption does not present a significant problem. To overcome this limitation, we present a fully ultra-high vacuum (UHV) compatible chopper system capable of operating at variable chopping frequencies up to 4 kHz. The lightweight aluminum chopper disk is coated with Ti and Au films to provide the required beam attenuation for soft and hard x-rays with photon energies up to about 12 keV. The chopper is used for lock-in detection of x-ray enhanced signals in SX-STM.

  18. Deposition and characterization of multilayers on thin foil x-ray mirrors for high-throughput x-ray telescopes

    DEFF Research Database (Denmark)

    Hussain, Ahsen M.; Joensen, Karsten D.; Hoeghoej, P.

    1996-01-01

    W/Si and Co/C multilayers have been deposited on epoxy- replicated Au mirrors from the ASTRO-E telescope project, SPectrum Roentgen Gamma (SRG) flight mirrors, DURAN glass substrates and Si witness wafers. A characterization of the multilayers with both hard x-rays and soft x-rays is presented. T....... This clearly indicates the effectiveness of the epoxy-replication process for the production of smooth substrates for multilayer deposition to be used in future x-ray telescopes....

  19. Active X-ray Optics for Generation-X, the Next High Resolution X-ray Observatory

    OpenAIRE

    Elvis, Martin; Brissenden, R. J.; Fabbiano, G.; Schwartz, D. A.; Reid, P.; Podgorski, W.; Eisenhower, M.; Juda, M.; Phillips, J.; Cohen, L.; Wolk, S.

    2006-01-01

    X-rays provide one of the few bands through which we can study the epoch of reionization, when the first galaxies, black holes and stars were born. To reach the sensitivity required to image these first discrete objects in the universe needs a major advance in X-ray optics. Generation-X (Gen-X) is currently the only X-ray astronomy mission concept that addresses this goal. Gen-X aims to improve substantially on the Chandra angular resolution and to do so with substantially larger effective ar...

  20. High-pressure studies with x-rays using diamond anvil cells

    Energy Technology Data Exchange (ETDEWEB)

    Shen, Guoyin; Mao, Ho Kwang

    2016-11-22

    Pressure profoundly alters all states of matter. The symbiotic development of ultrahigh-pressure diamond anvil cells, to compress samples to sustainable multi-megabar pressures; and synchrotron x-ray techniques, to probe materials' properties in situ, has enabled the exploration of rich high-pressure (HP) science. In this article, we first introduce the essential concept of diamond anvil cell technology, together with recent developments and its integration with other extreme environments. We then provide an overview of the latest developments in HP synchrotron techniques, their applications, and current problems, followed by a discussion of HP scientific studies using x-rays in the key multidisciplinary fields. These HP studies include: HP x-ray emission spectroscopy, which provides information on the filled electronic states of HP samples; HP x-ray Raman spectroscopy, which probes the HP chemical bonding changes of light elements; HP electronic inelastic x-ray scattering spectroscopy, which accesses high energy electronic phenomena, including electronic band structure, Fermi surface, excitons, plasmons, and their dispersions; HP resonant inelastic x-ray scattering spectroscopy, which probes shallow core excitations, multiplet structures, and spin-resolved electronic structure; HP nuclear resonant x-ray spectroscopy, which provides phonon densities of state and time-resolved Mössbauer information; HP x-ray imaging, which provides information on hierarchical structures, dynamic processes, and internal strains; HP x-ray diffraction, which determines the fundamental structures and densities of single-crystal, polycrystalline, nanocrystalline, and non-crystalline materials; and HP radial x-ray diffraction, which yields deviatoric, elastic and rheological information. Integrating these tools with hydrostatic or uniaxial pressure media, laser and resistive heating, and cryogenic cooling, has enabled investigations of the structural, vibrational, electronic, and

  1. High-pressure studies with x-rays using diamond anvil cells

    Science.gov (United States)

    Shen, Guoyin; Mao, Ho Kwang

    2017-01-01

    Pressure profoundly alters all states of matter. The symbiotic development of ultrahigh-pressure diamond anvil cells, to compress samples to sustainable multi-megabar pressures; and synchrotron x-ray techniques, to probe materials’ properties in situ, has enabled the exploration of rich high-pressure (HP) science. In this article, we first introduce the essential concept of diamond anvil cell technology, together with recent developments and its integration with other extreme environments. We then provide an overview of the latest developments in HP synchrotron techniques, their applications, and current problems, followed by a discussion of HP scientific studies using x-rays in the key multidisciplinary fields. These HP studies include: HP x-ray emission spectroscopy, which provides information on the filled electronic states of HP samples; HP x-ray Raman spectroscopy, which probes the HP chemical bonding changes of light elements; HP electronic inelastic x-ray scattering spectroscopy, which accesses high energy electronic phenomena, including electronic band structure, Fermi surface, excitons, plasmons, and their dispersions; HP resonant inelastic x-ray scattering spectroscopy, which probes shallow core excitations, multiplet structures, and spin-resolved electronic structure; HP nuclear resonant x-ray spectroscopy, which provides phonon densities of state and time-resolved Mössbauer information; HP x-ray imaging, which provides information on hierarchical structures, dynamic processes, and internal strains; HP x-ray diffraction, which determines the fundamental structures and densities of single-crystal, polycrystalline, nanocrystalline, and non-crystalline materials; and HP radial x-ray diffraction, which yields deviatoric, elastic and rheological information. Integrating these tools with hydrostatic or uniaxial pressure media, laser and resistive heating, and cryogenic cooling, has enabled investigations of the structural, vibrational, electronic, and

  2. The impact of the in-orbit background and the X-ray source intensity on the centroiding accuracy of the Swift X-ray telescope

    CERN Document Server

    Ambrosi, R M; Hill, J; Cheruvu, C; Abbey, A F; Short, A D T

    2002-01-01

    The optical components of the Swift Gamma Ray Burst Explorer X-ray Telescope (XRT), consisting of the JET-X spare flight mirror and a charge coupled device of the type used in the EPIC program, were used in a re-calibration study carried out at the Panter facility, which is part of the Max Planck Institute for Extraterrestrial Physics. The objective of this study was to check the focal length and the off axis performance of the mirrors and to show that the half energy width (HEW) of the on-axis point spread function (PSF) was of the order of 16 arcsec at 1.5 keV (Nucl. Instr. and Meth. A 488 (2002) 543; SPIE 4140 (2000) 64) and that a centroiding accuracy better that 1 arcsec could be achieved within the 4 arcmin sampling area designated by the Burst Alert Telescope (Nucl. Instr. and Meth. A 488 (2002) 543). The centroiding accuracy of the Swift XRT's optical components was tested as a function of distance from the focus and off axis position of the PSF (Nucl. Instr. and Meth. A 488 (2002) 543). The presence ...

  3. Inelastic X-ray scattering experiments at extreme conditions: high temperatures and high pressures

    Directory of Open Access Journals (Sweden)

    S.Hosokawa

    2008-03-01

    Full Text Available In this article, we review the present status of experimental techniques under extreme conditions of high temperature and high pressure used for inelastic X-ray scattering (IXS experiments of liquid metals, semiconductors, molten salts, molecular liquids, and supercritical water and methanol. For high temperature experiments, some types of single-crystal sapphire cells were designed depending on the temperature of interest and the sample thickness for the X-ray transmission. Single-crystal diamond X-ray windows attached to the externally heated high-pressure vessel were used for the IXS experiment of supercritical water and methanol. Some typical experimental results are also given, and the perspective of IXS technique under extreme conditions is discussed.

  4. The high-field magnet endstation for X-ray magnetic dichroism experiments at ESRF soft X-ray beamline ID32

    Science.gov (United States)

    Kummer, K.; Fondacaro, A.; Jimenez, E.; Velez-Fort, E.; Amorese, A.; Aspbury, M.; Yakhou-Harris, F.; van der Linden, P.; Brookes, N. B.

    2016-01-01

    A new high-field magnet endstation for X-ray magnetic dichroism experiments has been installed and commissioned at the ESRF soft X-ray beamline ID32. The magnet consists of two split-pairs of superconducting coils which can generate up to 9 T along the beam and up to 4 T orthogonal to the beam. It is connected to a cluster of ultra-high-vacuum chambers that offer a comprehensive set of surface preparation and characterization techniques. The endstation and the beam properties have been designed to provide optimum experimental conditions for X-ray magnetic linear and circular dichroism experiments in the soft X-ray range between 400 and 1600 eV photon energy. User operation started in November 2014. PMID:26917134

  5. Calibration of a high resolution grating soft x-ray spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Magee, E. W.; Dunn, J.; Brown, G. V.; Cone, K. V.; Park, J.; Porter, F. S.; Kilbourne, C. A.; Kelley, R. L.; Beiersdorfer, P.

    2010-10-01

    The calibration of the soft x-ray spectral response of a large radius of curvature, high resolution grating spectrometer (HRGS) with a back-illuminated charge-coupled device detector is reported. The instrument is cross-calibrated for the 10–50 Å waveband at the Lawrence Livermore National Laboratory electron beam ion trap (EBIT) x-ray source with the EBIT calorimeter spectrometer. The HRGS instrument is designed for laser-produced plasma experiments and is important for making high dynamic range measurements of line intensities, line shapes, and x-ray sources.

  6. High resolution, monochromatic x-ray topography capability at CHESS

    Energy Technology Data Exchange (ETDEWEB)

    Finkelstein, K. D., E-mail: kdf1@cornell.edu; Pauling, A.; Brown, Z. [CHESS, Cornell University, Ithaca, NY (United States); Jones, R. [Department of Physics, University of Connecticut, Storrs, CT (United States); Tarun, A.; Misra, D. S. [IIa Technologies (Singapore); Jupitz, S. [St. Mary’s College of Maryland, St. Mary’s City, MD (United States); Sagan, D. C. [CLASSE, Cornell University, Ithaca, NY (United States)

    2016-07-27

    CHESS has a monochromatic x-ray topography capability serving continually expanding user interest. The setup consists of a beam expanding monochromator, 6-circle diffactometer, and CHESS designed CMOS camera with real time sample-alignment capability. This provides rocking curve mapping with angle resolution as small as 2 µradians, spatial resolution to 3 microns, and field of view up to 7mm. Thus far the capability has been applied for: improving CVD-diamond growth, evaluating perfection of ultra-thin diamond membranes, correlating performance of diamond-based electronics with crystal defect structure, and defect analysis of single crystal silicon carbide. This paper describes our topography system, explains its capabilities, and presents experimental results from several applications.

  7. High efficiency replicated x-ray optics and fabrication method

    Science.gov (United States)

    Barbee, Jr., Troy W.; Lane, Stephen M.; Hoffman, Donald E.

    2001-01-01

    Replicated x-ray optics are fabricated by sputter deposition of reflecting layers on a super-polished reusable mandrel. The reflecting layers are strengthened by a supporting multilayer that results in stronger stress-relieved reflecting surfaces that do not deform during separation from the mandrel. The supporting multilayer enhances the ability to part the replica from the mandrel without degradation in surface roughness. The reflecting surfaces are comparable in smoothness to the mandrel surface. An outer layer is electrodeposited on the supporting multilayer. A parting layer may be deposited directly on the mandrel before the reflecting surface to facilitate removal of the layered, tubular optic device from the mandrel without deformation. The inner reflecting surface of the shell can be a single layer grazing reflection mirror or a resonant multilayer mirror. The resulting optics can be used in a wide variety of applications, including lithography, microscopy, radiography, tomography, and crystallography.

  8. Accuracy of dual energy X-ray absorptiometry (DXA) in assessing carcass composition from different pig populations.

    Science.gov (United States)

    Soladoye, O P; López Campos, Ó; Aalhus, J L; Gariépy, C; Shand, P; Juárez, M

    2016-11-01

    The accuracy of dual energy X-ray absorptiometry (DXA) in assessing carcass composition from pigs with diverse characteristics was examined in the present study. A total of 648 pigs from three different sire breeds, two sexes, two slaughter weights and three different diets were employed. DXA estimations were used to predict the dissected/chemical yield for lean and fat of carcass sides and primal cuts. The accuracy of the predictions was assessed based on coefficient of determination (R(2)) and residual standard deviation (RSD). The linear relationships for dissected fat and lean for all the primal cuts and carcass sides were high (R(2)>0.94, Ppork bellies were also high (R(2)>0.94, P<0.01), with RSD <2.9%. These linear relationships remained high over the full range of variation in the pig population, except for sire breed, where the coefficient of determination decreased when carcasses were classified based on this variable. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. 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.

  10. Ultra-high aspect ratio high-resolution nanofabrication for hard X-ray diffractive optics

    Science.gov (United States)

    Chang, Chieh; Sakdinawat, Anne

    2014-06-01

    Although diffractive optics have played a major role in nanoscale soft X-ray imaging, high-resolution and high-efficiency diffractive optics have largely been unavailable for hard X-rays where many scientific, technological and biomedical applications exist. This is owing to the long-standing challenge of fabricating ultra-high aspect ratio high-resolution dense nanostructures. Here we report significant progress in ultra-high aspect ratio nanofabrication of high-resolution, dense silicon nanostructures using vertical directionality controlled metal-assisted chemical etching. The resulting structures have very smooth sidewalls and can be used to pattern arbitrary features, not limited to linear or circular. We focus on the application of X-ray zone plate fabrication for high-efficiency, high-resolution diffractive optics, and demonstrate the process with linear, circular, and spiral zone plates. X-ray measurements demonstrate high efficiency in the critical outer layers. This method has broad applications including patterning for thermoelectric materials, battery anodes and sensors among others.

  11. Next Generation X-Ray Optics: High-Resolution, Light-Weight, and Low-Cost

    Science.gov (United States)

    Zhang, William W.

    2012-01-01

    mirror segments is the continued development and perfection of alignment and integration techniques, for incorporating individual mirror segments into a precision mirror assembly. Recently, we have been developing a technique called edge-bonding, which has achieved an accuracy to enable 10-arcsecond x-ray telescopes. Currently, we are investigating and improving the long-term alignment stability of so-bonded mirrors. Next, we shall refine this process to enable 5-arsecond x-ray telescopes. This technology development program includes all elements to demonstrate progress toward TRL-6: metrology; x-ray performance tests; coupled structural, thermal, and optical performance analysis, and environmental testing.

  12. Deep X-ray Observations of 3 exceptional high-z clusters of galaxies

    Science.gov (United States)

    Hlavacek-Larrondo, Julie

    2015-10-01

    We propose to obtain deep Chandra X-ray observations of 3 exceptional high-z (z>0.5) clusters of galaxies, which stand out as extremely X-ray luminous (L X-ray>>10^44 erg/s), relaxed cool-core clusters with evidence of X-ray cavities and a previous epoch of astrophysical feedback. This proposal will double the number of z>0.57 clusters with deep Chandra observations. The observations will significantly help in our understanding of the evolution and formation of massive clusters, the role of active galactic nuclei in astrophysical feedback and the distribution of metals in clusters at high-z, and will be used to place new constraints on the dark energy and cosmology. In summary, in just 425 ks, this proposal will advance several aspects of high-z clusters physics.

  13. Speckle-based at-wavelength metrology of X-ray mirrors with super accuracy

    Energy Technology Data Exchange (ETDEWEB)

    Kashyap, Yogesh; Wang, Hongchang; Sawhney, Kawal, E-mail: kawal.sawhney@diamond.ac.uk [Diamond Light Source, Harwell Science and Innovation Campus, Didcot OX11 0DE (United Kingdom)

    2016-05-15

    X-ray active mirrors, such as bimorph and mechanically bendable mirrors, are increasingly being used on beamlines at modern synchrotron source facilities to generate either focused or “tophat” beams. As well as optical tests in the metrology lab, it is becoming increasingly important to optimise and characterise active optics under actual beamline operating conditions. Recently developed X-ray speckle-based at-wavelength metrology technique has shown great potential. The technique has been established and further developed at the Diamond Light Source and is increasingly being used to optimise active mirrors. Details of the X-ray speckle-based at-wavelength metrology technique and an example of its applicability in characterising and optimising a micro-focusing bimorph X-ray mirror are presented. Importantly, an unprecedented angular sensitivity in the range of two nanoradians for measuring the slope error of an optical surface has been demonstrated. Such a super precision metrology technique will be beneficial to the manufacturers of polished mirrors and also in optimization of beam shaping during experiments.

  14. Speckle-based at-wavelength metrology of X-ray mirrors with super accuracy.

    Science.gov (United States)

    Kashyap, Yogesh; Wang, Hongchang; Sawhney, Kawal

    2016-05-01

    X-ray active mirrors, such as bimorph and mechanically bendable mirrors, are increasingly being used on beamlines at modern synchrotron source facilities to generate either focused or "tophat" beams. As well as optical tests in the metrology lab, it is becoming increasingly important to optimise and characterise active optics under actual beamline operating conditions. Recently developed X-ray speckle-based at-wavelength metrology technique has shown great potential. The technique has been established and further developed at the Diamond Light Source and is increasingly being used to optimise active mirrors. Details of the X-ray speckle-based at-wavelength metrology technique and an example of its applicability in characterising and optimising a micro-focusing bimorph X-ray mirror are presented. Importantly, an unprecedented angular sensitivity in the range of two nanoradians for measuring the slope error of an optical surface has been demonstrated. Such a super precision metrology technique will be beneficial to the manufacturers of polished mirrors and also in optimization of beam shaping during experiments.

  15. Fabrication of high aspect ratio X-ray grating using silicon dry etching method

    Science.gov (United States)

    Noda, Daiji; Tokuoka, Atsushi; Hattori, Tadashi

    2012-07-01

    We have fabricated the high aspect ratio X-ray gratings for X-ray phase imaging. Silicon dry etching technology makes it possible to fabricate rectangular structures by repeating two steps of etching process and protection process. Then, we introduce the ability of Si dry etching technology in order to fabricate un-tapered, high precision Si microstructures containing rectangular patterns for X-ray grating. Au electroforming was realized from the bottom of the Si microstructure groove using sidewall protection method. In these technologies, we succeeded in fabricating about 40 μm thick, void-free Au structures in a space as narrow as 2.6 μm in large effective area of 60 mm squares on 4 inch Si wafer. Therefore, it is expected to be used in the production of a narrow pitch and higher aspect ratio microstructures such as X-ray gratings.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-02-12

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

  17. EDS measurements of X-ray intensity at WDS precision and accuracy using a silicon drift detector.

    Science.gov (United States)

    Ritchie, Nicholas W M; Newbury, Dale E; Davis, Jeffrey M

    2012-08-01

    The accuracy and precision of X-ray intensity measurements with a silicon drift detector (SDD) are compared with the same measurements performed on a wavelength dispersive spectrometer (WDS) for a variety of elements in a variety of materials. In cases of major (>0.10 mass fraction) and minor (>0.01 mass fraction) elements, the SDD is demonstrated to perform as well or better than the WDS. This is demonstrated both for simple cases in which the spectral peaks do not interfere (SRM-481, SRM-482, and SRM-479a), and for more difficult cases in which the spectral peaks have significant interferences (the Ba L/Ti K lines in a series of Ba/Ti glasses and minerals). We demonstrate that even in the case of significant interference high count SDD spectra are capable of accurately measuring Ti in glasses with Ba:Ti mass fraction ratios from 2.7:1 to 23.8:1. The results suggest that for many measurements wavelength spectrometry can be replaced with an SDD with improved accuracy and precision.

  18. Microcalorimetry for High-Resolution X-Ray Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Friedrich, Stephen [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2017-01-03

    Magnetic Microcalorimeters (MMCs) are gamma-ray detectors with an energy resolution 10x higher than high-purity germanium detectors. They can increase the accuracy of non-destructive analysis of nuclear materials, enable the detection of new isotopes (e.g. Pu-242 of U-236), and improve nuclear data in cases where Ge detectors are limited by line overlap. MMCs consist of a magnetic sensor operated at temperatures below 50 mK, and they infer gamma-ray energies from the change in magnetization due to the temperature increase after gamma-ray absorption. The goal of this project is to further increase the energy resolution and sensitivity of MMC gamma detectors.

  19. High resolution x-ray CMT: Reconstruction methods

    Energy Technology Data Exchange (ETDEWEB)

    Brown, J.K.

    1997-02-01

    This paper qualitatively discusses the primary characteristics of methods for reconstructing tomographic images from a set of projections. These reconstruction methods can be categorized as either {open_quotes}analytic{close_quotes} or {open_quotes}iterative{close_quotes} techniques. Analytic algorithms are derived from the formal inversion of equations describing the imaging process, while iterative algorithms incorporate a model of the imaging process and provide a mechanism to iteratively improve image estimates. Analytic reconstruction algorithms are typically computationally more efficient than iterative methods; however, analytic algorithms are available for a relatively limited set of imaging geometries and situations. Thus, the framework of iterative reconstruction methods is better suited for high accuracy, tomographic reconstruction codes.

  20. High Miller-index germanium crystals for high-energy x-ray imaging applications.

    Science.gov (United States)

    Koch, J A; Lee, J J; Haugh, M J

    2015-12-01

    Near-normal-incidence bent crystals are widely used for x-ray imaging applications. Advantages include high collection solid angle and potentially high efficiency for narrow-band sources, while disadvantages include relatively large (several Å) interatomic spacings and a limited number of suitable matches between a crystal 2d value and an integral multiple of useful emission line wavelengths. The disadvantages become more significant at x-ray energies >10  keV. The former disadvantage can be mitigated by using high-order reflections from crystal planes having low Miller indices, but both disadvantages can be mitigated by using low-order reflections from crystal planes having high Miller indices. We report here on integrated reflectivity measurements we performed of Ge (15,7,7) (2d=0.6296  Å), a candidate for imaging Ru He-α (θ(B)=87°). We find good agreement with calculations, and the data show a multitude of closely spaced reflections with slightly different Bragg angles including a fifth-order reflection of Ge (3,1,1) that has comparable reflectivity. This demonstrates that arbitrary choices of Miller indices in Ge crystals can be used to fine-tune Bragg angles for near-normal-incidence x-ray imaging at tens of kiloelectron volt x-ray energies with minimal lower-energy contamination from lower-order reflections, and that existing calculational tools can be used to reliably estimate integrated reflectivity.

  1. High contrast soft tissue imaging based on multi-energy x-ray

    Science.gov (United States)

    Oh, Hyun-Hwa; Sung, Young-Hun; Kim, Sung-Su; Kwon, Jae-Hyun; Lee, Seong-Deok; Kim, Chang-Yeong

    2011-03-01

    Breast soft tissues have similar x-ray attenuations to mass tissue. Overlapping breast tissue structure often obscures mass and microcalcification, essential to the early detection of breast cancer. In this paper, we propose new method to generate the high contrast mammogram with distinctive features of a breast cancer by using multiple images with different x-ray energy spectra. On the experiments with mammography simulation and real breast tissues, the proposed method has provided noticeable images with obvious mass structure and microcalifications.

  2. Thermal expansion in UO 2 determined by high-energy X-ray diffraction

    Energy Technology Data Exchange (ETDEWEB)

    Guthrie, M.; Benmore, C. J.; Skinner, L. B.; Alderman, O. L. G.; Weber, J. K. R.; Parise, J. B.; Williamson, M.

    2016-10-01

    Here we present crystallographic analyses of high-energy X-ray diffraction data on polycrystalline UO2 up to the melting temperature. The Rietveld refinements of our X-ray data are in agreement with previous measurements, but are systematically located around the upper bound of their uncertainty, indicating a slightly steeper trend of thermal expansion compared to established values. This observation is consistent with recent first principles calculations.

  3. ANALYSIS AND MITIGATION OF X-RAY HAZARD GENERATED FROM HIGH INTENSITY LASER-TARGET INTERACTIONS

    Energy Technology Data Exchange (ETDEWEB)

    Qiu, R.; Liu, J.C.; Prinz, A.A.; Rokni, S.H.; Woods, M.; Xia, Z.; /SLAC

    2011-03-21

    Interaction of a high intensity laser with matter may generate an ionizing radiation hazard. Very limited studies have been made, however, on the laser-induced radiation protection issue. This work reviews available literature on the physics and characteristics of laser-induced X-ray hazards. Important aspects include the laser-to-electron energy conversion efficiency, electron angular distribution, electron energy spectrum and effective temperature, and bremsstrahlung production of X-rays in the target. The possible X-ray dose rates for several femtosecond Ti:sapphire laser systems used at SLAC, including the short pulse laser system for the Matter in Extreme Conditions Instrument (peak power 4 TW and peak intensity 2.4 x 10{sup 18} W/cm{sup 2}) were analysed. A graded approach to mitigate the laser-induced X-ray hazard with a combination of engineered and administrative controls is also proposed.

  4. Investigating high speed phenomena in laser plasma interactions using dilation x-ray imager (invited)

    Energy Technology Data Exchange (ETDEWEB)

    Nagel, S. R., E-mail: nagel7@llnl.gov; Bell, P. M.; Bradley, D. K.; Ayers, M. J.; Piston, K.; Felker, B. [Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550 (United States); Hilsabeck, T. J.; Kilkenny, J. D.; Chung, T.; Sammuli, B. [General Atomics, P.O. Box 85608, San Diego, California 92186-5608 (United States); Hares, J. D.; Dymoke-Bradshaw, A. K. L. [Kentech Instruments Ltd., Wallingford, Oxfordshire OX10 (United Kingdom)

    2014-11-15

    The DIlation X-ray Imager (DIXI) is a new, high-speed x-ray framing camera at the National Ignition Facility (NIF) sensitive to x-rays in the range of ≈2–17 keV. DIXI uses the pulse-dilation technique to achieve a temporal resolution of less than 10 ps, a ≈10× improvement over conventional framing cameras currently employed on the NIF (≈100 ps resolution), and otherwise only attainable with 1D streaked imaging. The pulse-dilation technique utilizes a voltage ramp to impart a velocity gradient on the signal-bearing electrons. The temporal response, spatial resolution, and x-ray sensitivity of DIXI are characterized with a short x-ray impulse generated using the COMET laser facility at Lawrence Livermore National Laboratory. At the NIF a pinhole array at 10 cm from target chamber center (tcc) projects images onto the photocathode situated outside the NIF chamber wall with a magnification of ≈64×. DIXI will provide important capabilities for warm-dense-matter physics, high-energy-density science, and inertial confinement fusion, adding important capabilities to temporally resolve hot-spot formation, x-ray emission, fuel motion, and mix levels in the hot-spot at neutron yields of up to 10{sup 17}. We present characterization data as well as first results on electron-transport phenomena in buried-layer foil experiments.

  5. High Dynamic Range X-Ray Detector Pixel Architectures Utilizing Charge Removal

    Science.gov (United States)

    Weiss, Joel T.; Shanks, Katherine S.; Philipp, Hugh T.; Becker, Julian; Chamberlain, Darol; Purohit, Prafull; Tate, Mark W.; Gruner, Sol M.

    2017-04-01

    Several charge integrating CMOS pixel front ends utilizing charge removal techniques have been fabricated to extend dynamic range for X-ray diffraction applications at synchrotron sourcesand X-ray free electron lasers (XFELs). The pixels described herein build on the mixed mode pixel array detector (MM-PAD) framework, developed previously by our group to perform high dynamic range imaging. These new pixels boast several orders of magnitude improvement in maximum flux over the MM-PAD, which is capable of measuring a sustained flux in excess of 108 X-rays/pixel/s while maintaining sensitivity to smaller signals, down to single X-rays. To extend dynamic range, charge is removed from the integration node of the frontend amplifier without interrupting integration. The number of times this process occurs is recorded by a digital counter in the pixel. The parameter limiting full well is, thereby, shifted from the size of an integration capacitor to the depth of a digital counter. The result is similar to that achieved by counting pixel array detectors, but the integrators presented here are designed to tolerate a sustained flux > 1011 X-rays/pixel/s. Pixel front-end linearity was evaluated by direct current injection and results are presented. A small-scale readout ASIC utilizing these pixel architectures has been fabricated and the use of these architectures to increase single X-ray pulse dynamic range at XFELs is discussed briefly.

  6. Diagnostic imaging of gout: comparison of high-resolution US versus conventional X-ray

    Energy Technology Data Exchange (ETDEWEB)

    Rettenbacher, Thomas; Ennemoser, Sybille; Weirich, Harald [Innsbruck Medical University, Department of Radiology, Innsbruck (Austria); Ulmer, Hanno [Innsbruck Medical University, Department of Medical Statistics, Informatics, and Health Economics, Innsbruck (Austria); Hartig, Frank; Klotz, Werner; Herold, Manfred [Innsbruck Medical University, Department of Internal Medicine, Innsbruck (Austria)

    2008-03-15

    The aim was to compare X-ray and ultrasound (US) in diagnosing gout. In a prospective study, 105 consecutive patients with clinical suspicion of gout underwent conventional X-ray und high-resolution US in order to help in arriving at a definite diagnosis. X-ray findings suggestive of gout included soft-tissue opacifications with densities between soft tissue and bone, articular and periarticular bone erosions, and osteophytes at the margins of opacifications or erosions. US findings suggestive of gout included bright stippled foci and hyperechoic soft-tissue areas. Fifty-five patients had a definite diagnosis of gout (102 involved sites), 31 patients were diagnosed as having another disease (59 involved sites), and 19 patients were excluded from the study because a definite diagnosis could not be established. X-ray suggested gout with a sensitivity of 31% (32/102) and a specificity of 93% (55/59), whereas US suggested gout with a sensitivity of 96% (98/102) and a specificity of 73% (43/59). US was much more sensitive than conventional X-ray but less specific. Our data show that US often provided additional diagnostic information in patients with clinical suspicion of gout when laboratory findings and X-ray results were negative or inconclusive and should therefore be used in these cases. (orig.)

  7. The chemical sensitivity of X-ray spectroscopy: high energy resolution XANES versus X-ray emission spectroscopy of substituted ferrocenes.

    Science.gov (United States)

    Atkins, Andrew J; Bauer, Matthias; Jacob, Christoph R

    2013-06-07

    X-ray spectroscopy at the metal K-edge is an important tool for understanding catalytic processes and provides insight into the geometric and electronic structures of transition metal complexes. In particular, X-ray emission-based methods such as high-energy resolution fluorescence detection (HERFD), X-ray absorption near-edge spectroscopy (XANES) and valence-to-core X-ray emission spectroscopy (V2C-XES) hold the promise of providing increased chemical sensitivity compared to conventional X-ray absorption spectroscopy. Here, we explore the ability of HERFD-XANES and V2C-XES spectroscopy to distinguish substitutions beyond the directly coordinated atoms for the example of ferrocene and selected ferrocene derivatives. The experimental spectra are assigned and interpreted through the use of density functional theory (DFT) calculations. We find that while the pre-edge peaks in the HERFD-XANES spectra are affected by substituents at the cyclopentadienyl ring containing π-bonds [A. J. Atkins, Ch. R. Jacob and M. Bauer, Chem.-Eur. J., 2012, 18, 7021], the V2C-XES spectra are virtually unchanged. The pre-edge in HERFD-XANES probes the weak transition to unoccupied metal d-orbitals, while the V2C-XES spectra are determined by dipole-allowed transitions from occupied ligand orbitals to the 1s core hole. The latter turn out to be less sensitive to changes beyond the first coordination shell.

  8. Medical CT image reconstruction accuracy in the presence of metal objects using x-rays up to 1 MeV with x-ray targets of beryllium, carbon, aluminum, copper, and tungsten

    Science.gov (United States)

    Clayton, James; Ganguly, Arundhuti; Virshup, Gary

    2012-04-01

    Flat panels imagers based on amorphous silicon technology (a-Si) for digital radiography have been accepted by the medical community as having several advantages over film-based systems. Radiotherapy treatment planning systems employ computed tomographic (CT) data sets and projection images to delineate tumor targets and normal structures that are to be spared from radiation treatment. The accuracy of CT numbers is crucial for radiotherapy dose calculations. Conventional CT scanners operating at kilovoltage X-ray energies typically exhibit significant image reconstruction artifacts in the presence of metal implants in human body. Megavoltage X-ray energies have problems maintaining contrast sensitivity for the same dose as kV X-ray systems. We intend to demonstrate significant improvement in metal artifact reductions and electron density measurements using an amorphous silicon a-Si imager obtained with an X-ray source that can operate at energies up to 1 MeV. We will investigate the ability to maintain contrast sensitivity at this higher X-ray energy by using targets with lower atomic numbers and appropriate amounts of Xray filtration than are typically used as X-ray production targets and filters.

  9. Cellulose/inorganic-composite fibers for producing textile fabrics of high X-ray absorption properties

    Energy Technology Data Exchange (ETDEWEB)

    Günther, Karoline; Giebing, Christina; Askani, Antonia [FTB, Hochschule Niederrhein – University of Applied Science, Faculty of Textile and Clothing Technology, Webschulstr. 31, 41065 Mönchengladbach (Germany); Leisegang, Tilmann [Saxray GmbH, Maria-Reiche-Str. 1, 01109 Dresden (Germany); Krieg, Marcus [TITK, Thüringisches Institut für Textil- und Kunststoff-Forschung e.V., Breitscheidstraße 97, 07407 Rudolstadt (Germany); Kyosev, Yordan; Weide, Thomas [FTB, Hochschule Niederrhein – University of Applied Science, Faculty of Textile and Clothing Technology, Webschulstr. 31, 41065 Mönchengladbach (Germany); Mahltig, Boris, E-mail: Boris.Mahltig@hs-niederrhein.de [FTB, Hochschule Niederrhein – University of Applied Science, Faculty of Textile and Clothing Technology, Webschulstr. 31, 41065 Mönchengladbach (Germany)

    2015-11-01

    Common textile materials as cotton or polyester do not possess reliable X-ray absorption properties. This is due to their morphology and chemical composition in particular. Common fibers are built up from organic polymers containing mainly the elements carbon, hydrogen, oxygen and nitrogen. These “light” elements only have low X-ray absorption coefficients. In contrast, inorganic materials composed of “heavy” elements with high atomic numbers, e.g. barium or bismuth, exhibit X-ray absorption coefficients higher by up to two orders of magnitude. To obtain a flexible yarn with high X-ray absorption properties both these materials, the organic polymer and the inorganic X-ray absorber, are combined to an inorganic/organic composite fiber material. Hence, as the organic component cellulose from modified Lyocell-process is used as carrier fiber and blended with inorganic absorber particles of low toxicity and high absorption coefficients, as bariumsulphate, bariumtitanate or bismuthoxide. A content of inorganic absorber particles equally distributed in the whole fiber of up to 20% is achieved. The composite fibers are produced as staple or filament fibers and processed to multifilament or staple fiber yarns. The staple fiber yarns are rotor-spinned to increase the comfort of the subsequent textile material. Several woven fabrics, considering multilayer structure and different warp/weft density, are developed. The energy dependent X-ray shielding properties are determined in dependence on the different yarn compositions, yarn types and structural parameters of the woven fabrics. As a result, a production process of textile materials with comfortable and dedicated X-ray absorption properties is established. It offers a promising opportunity for manufacturing of specialized textiles, working clothes or uniforms applicable for medicine, air craft and security personal, mining as well as for innovative composite materials. - Highlights: • Preparation of cellulosic

  10. Characterization of metallic nanoparticles by high-resolution X-ray absorption and X-ray emission spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Kuehn, Timna-Josua

    2012-03-15

    In almost all areas of technology, metallic nanoparticles are of interest due to their special thermal, electronic, magnetic and optical properties. Their special properties are mainly due to their small size which implies the relevance of quantum effects as well as the significance of the surface: For 2 nm nanoparticles, the surface-to-volume ratio is already 1:1. However, the identification of surface-to-volume interactions - that are responsible for the new properties - is a difficult task due to the small size that inhibits a lot of 'standard' techniques to be applicable. Here X-ray absorption/emission spectroscopy (XAS/XES) is a favorable tool for the characterization of nanoparticles, independent on size, degree of crystallinity and shape/condition of the surface. Using XAS, a tempered nanosized Co{sub 3}Pt/C catalyst have been investigated. Its outstanding oxygen-reduction reaction (ORR) properties in a fuel cell could be related to a lowered Pt 5d-band center connected to a tightened Pt-Pt bonding distance, leading to a weakening of the oxygen adsorption strength so that the ORR may proceed faster. One drawback remains, however, as the properties found by (standard) XAS are summed up for different chemical environments of the chosen element. Thus, no distinction can be made between, e.g., the pure metal in a nanoparticles' interior and the ligated metal in the outer shells or surface. Here, high-resolution fluorescence-detected XAS (HRFD-XAS) provides additional opportunities as, due to its chemical sensitivity, it leads to site-selective XAS. For a system of 6 nm sized Co nanoparticles, build up of a metallic core surrounded by a protecting shell, that resulted from the 'smooth oxidation' process, this technique of site-selective XAS was proven to be applicable. For the first time, the interior and outer shell of a metallic nanoparticle could be characterized separately. In particular, the Co-hcp phase could be determined for the

  11. Influence by x-ray facula on dimension measurement

    Science.gov (United States)

    Qin, Xulei; Li, Ye; Duanmu, Qingduo; Zhao, Peng

    2015-03-01

    Based on the imaging features of the original image intensifier of X-ray, the light halo caused by X-ray projective halation is analyzed, the result shows the stray X-ray energy is lower than the direct X-ray energy. The screen brightness generated by the image intensifier of X-ray stimulated by the stray X-ray energy is weaker than that generated by the direct X-ray energy. In addition the projector facula reflected from the direct X-ray is focused on the central region of X-ray image intensifier, therefore a toroidal ring similar to the solar halation is formed around the projector halation. The results of the theoretical analysis and experimental discovery show this phenomenon caused by X-ray tube on X-ray image intensifier can not be eliminated and in the system of X-ray size detection composed of them the X-ray halation will reduce the detection accuracy resulting in measurement results' deviation dispersion under given conditions. This kind of nonlinear system error can not be canceled out by the segmented modification of coefficient compensation but it can be restrained through the adjustment of correction coefficients. After the physical testing and comparison of the physical normal size the accuracy of 0.1mm of the compensated X-ray measurement results after the adjustment of correction coefficient has been reached. The results are highly reproducible and the method of the segmented coefficient compensation has been improved.

  12. Calculating the X-Ray Fluorescence from the Planet Mercury Due to High-Energy Electrons

    Science.gov (United States)

    Burbine, T. H.; Trombka, J. I.; Bergstrom, P. M., Jr.; Christon, S. P.

    2005-01-01

    The least-studied terrestrial planet is Mercury due to its proximity to the Sun, which makes telescopic observations and spacecraft encounters difficult. Our lack of knowledge about Mercury should change in the near future due to the recent launching of MESSENGER, a Mercury orbiter. Another mission (BepiColombo) is currently being planned. The x-ray spectrometer on MESSENGER (and planned for BepiColombo) can characterize the elemental composition of a planetary surface by measuring emitted fluorescent x-rays. If electrons are ejected from an atom s inner shell by interaction with energetic particles such as photons, electrons, or ions, electrons from an outer shell can transfer to the inner shell. Characteristic x-rays are then emitted with energies that are the difference between the binding energy of the ion in its excited state and that of the ion in its ground state. Because each element has a unique set of energy levels, each element emits x-rays at a unique set of energies. Electrons and ions usually do not have the needed flux at high energies to cause significant x-ray fluorescence on most planetary bodies. This is not the case for Mercury where high-energy particles were detected during the Mariner 10 flybys. Mercury has an intrinsic magnetic field that deflects the solar wind, resulting in a bow shock in the solar wind and a magnetospheric cavity. Electrons and ions accelerated in the magnetosphere tend to follow its magnetic field lines and can impact the surface on Mercury s dark side Modeling has been done to determine if x-ray fluorescence resulting from the impact of high-energy electrons accelerated in Mercury's magnetosphere can be detected by MESSENGER. Our goal is to understand how much bulk chemical information can be obtained from x-ray fluorescence measurements on the dark side of Mercury.

  13. A broadband x-ray imaging spectroscopy with high-angular resolution: the FORCE mission

    Science.gov (United States)

    Mori, Koji; Tsuru, Takeshi Go; Nakazawa, Kazuhiro; Ueda, Yoshihiro; Okajima, Takashi; Murakami, Hiroshi; Awaki, Hisamitsu; Matsumoto, Hironori; Fukazawa, Yasushi; Tsunemi, Hiroshi; Takahashi, Tadayuki; Zhang, William W.

    2016-07-01

    We are proposing FORCE (Focusing On Relativistic universe and Cosmic Evolution) as a future Japan-lead Xray observatory to be launched in the mid 2020s. Hitomi (ASTRO-H) possesses a suite of sensitive instruments enabling the highest energy-resolution spectroscopy in soft X-ray band, a broadband X-ray imaging spectroscopy in soft and hard X-ray bands, and further high energy coverage up to soft gamma-ray band. FORCE is the direct successor to the broadband X-ray imaging spectroscopy aspect of Hitomi (ASTRO-H) with significantly higher angular resolution. The current design of FORCE defines energy band pass of 1-80 keV with angular resolution of black holes" in various mass-scales: "buried supermassive black holes (SMBHs)" (> 104 M⊙) residing in the center of galaxies in a cosmological distance, "intermediate-mass black holes" (102-104 M⊙) acting as the possible seeds from which SMBHs grow, and "orphan stellar-mass black holes" (< 102 M⊙) without companion in our Galaxy. In addition to these missing BHs, hunting for the nature of relativistic particles at various astrophysical shocks is also in our scope, utilizing the broadband X-ray coverage with high angular-resolution. FORCE are going to open a new era in these fields. The satellite is proposed to be launched with the Epsilon vehicle that is a Japanese current solid-fuel rocket. FORCE carries three identical pairs of Super-mirror and wide-band X-ray detector. The focal length is currently planned to be 10 m. The silicon mirror with multi-layer coating is our primary choice to achieve lightweight, good angular optics. The detector is a descendant of hard X-ray imager onboard Hitomi (ASTRO-H) replacing its silicon strip detector with SOI-CMOS silicon pixel detector, allowing an extension of the low energy threshold down to 1 keV or even less.

  14. High resolution x-ray microtomography of biological samples: Requirements and strategies for satisfying them

    Energy Technology Data Exchange (ETDEWEB)

    Loo, B.W. Jr. [Univ. of California, San Francisco, CA (United States)]|[Univ. of California, Davis, CA (United States)]|[Lawrence Berkeley National Lab., CA (United States); Rothman, S.S. [Univ. of California, San Francisco, CA (United States)]|[Lawrence Berkeley National Lab., CA (United States)

    1997-02-01

    High resolution x-ray microscopy has been made possible in recent years primarily by two new technologies: microfabricated diffractive lenses for soft x-rays with about 30-50 nm resolution, and high brightness synchrotron x-ray sources. X-ray microscopy occupies a special niche in the array of biological microscopic imaging methods. It extends the capabilities of existing techniques mainly in two areas: a previously unachievable combination of sub-visible resolution and multi-micrometer sample size, and new contrast mechanisms. Because of the soft x-ray wavelengths used in biological imaging (about 1-4 nm), XM is intermediate in resolution between visible light and electron microscopies. Similarly, the penetration depth of soft x-rays in biological materials is such that the ideal sample thickness for XM falls in the range of 0.25 - 10 {mu}m, between that of VLM and EM. XM is therefore valuable for imaging of intermediate level ultrastructure, requiring sub-visible resolutions, in intact cells and subcellular organelles, without artifacts produced by thin sectioning. Many of the contrast producing and sample preparation techniques developed for VLM and EM also work well with XM. These include, for example, molecule specific staining by antibodies with heavy metal or fluorescent labels attached, and sectioning of both frozen and plastic embedded tissue. However, there is also a contrast mechanism unique to XM that exists naturally because a number of elemental absorption edges lie in the wavelength range used. In particular, between the oxygen and carbon absorption edges (2.3 and 4.4 nm wavelength), organic molecules absorb photons much more strongly than does water, permitting element-specific imaging of cellular structure in aqueous media, with no artifically introduced contrast agents. For three-dimensional imaging applications requiring the capabilities of XM, an obvious extension of the technique would therefore be computerized x-ray microtomography (XMT).

  15. Bismuth Passivation Technique for High-Resolution X-Ray Detectors

    Science.gov (United States)

    Chervenak, James; Hess, Larry

    2013-01-01

    The Athena-plus team requires X-ray sensors with energy resolution of better than one part in 3,000 at 6 keV X-rays. While bismuth is an excellent material for high X-ray stopping power and low heat capacity (for large signal when an X-ray is stopped by the absorber), oxidation of the bismuth surface can lead to electron traps and other effects that degrade the energy resolution. Bismuth oxide reduction and nitride passivation techniques analogous to those used in indium passivation are being applied in a new technique. The technique will enable improved energy resolution and resistance to aging in bismuth-absorber-coupled X-ray sensors. Elemental bismuth is lithographically integrated into X-ray detector circuits. It encounters several steps where the Bi oxidizes. The technology discussed here will remove oxide from the surface of the Bi and replace it with nitridized surface. Removal of the native oxide and passivating to prevent the growth of the oxide will improve detector performance and insulate the detector against future degradation from oxide growth. Placing the Bi coated sensor in a vacuum system, a reduction chemistry in a plasma (nitrogen/hydrogen (N2/H2) + argon) is used to remove the oxide and promote nitridization of the cleaned Bi surface. Once passivated, the Bi will perform as a better X-ray thermalizer since energy will not be trapped in the bismuth oxides on the surface. A simple additional step, which can be added at various stages of the current fabrication process, can then be applied to encapsulate the Bi film. After plasma passivation, the Bi can be capped with a non-diffusive layer of metal or dielectric. A non-superconducting layer is required such as tungsten or tungsten nitride (WNx).

  16. High-resolution x-ray imaging for microbiology at the Advanced Photon Source

    Energy Technology Data Exchange (ETDEWEB)

    Lai, B.; Kemner, K. M.; Maser, J.; Schneegurt, M. A.; Cai, Z.; Ilinski, P. P.; Kulpa, C. F.; Legnini, D. G.; Nealson, K. H.; Pratt, S. T.; Rodrigues, W.; Tischler, M. L.; Yun, W.

    1999-11-02

    Exciting new applications of high-resolution x-ray imaging have emerged recently due to major advances in high-brilliance synchrotrons sources and high-performance zone plate optics. Imaging with submicron resolution is now routine with hard x-rays: the authors have demonstrated 150 run in the 6--10 keV range with x-ray microscopes at the Advanced Photon Source (APS), a third-generation synchrotrons radiation facility. This has fueled interest in using x-ray imaging in applications ranging from the biomedical, environmental, and materials science fields to the microelectronics industry. One important application they have pursued at the APS is a study of the microbiology of bacteria and their associated extracellular material (biofilms) using fluorescence microanalysis. No microscopy techniques were previously available with sufficient resolution to study live bacteria ({approx}1 {micro}m x 4 {micro}m in size) and biofilms in their natural hydrated state with better than part-per-million elemental sensitivity and the capability of determining g chemical speciation. In vivo x-ray imaging minimizes artifacts due to sample fixation, drying, and staining. This provides key insights into the transport of metal contaminants by bacteria in the environment and potential new designs for remediation and sequestration strategies.

  17. Highly bright X-ray generator using heat of fusion with a specially designed rotating anticathode

    Energy Technology Data Exchange (ETDEWEB)

    Sakabe, N., E-mail: nsakabe@sbsp.jp [PF, High Energy Accelerator Research Organization (KEK), 1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan); Foundation for Advancement of International Science, 586-9 Akatsuka, Tsukuba, Ibaraki 305-0062 (Japan); Ohsawa, S.; Sugimura, T.; Ikeda, M.; Tawada, M. [Accelerator Laboratory, High Energy Accelerator Research Organization (KEK), 1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan); Watanabe, N. [Synchrotron Radiation Research Center, Nagoya University, Chikusa, Nagoya, Aichi 464-8603 (Japan); Sasaki, K. [Nagoya University, Chikusa, Nagoya, Aichi 464-8601 (Japan); Ohshima, K. [Institute of Materials Science, University of Tsukuba, 1-1-1 Tennoudai, Tsukuba, Ibaraki 305-8573 (Japan); Wakatsuki, M. [AIST, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8565 (Japan); Sakabe, K. [Foundation for Advancement of International Science, 586-9 Akatsuka, Tsukuba, Ibaraki 305-0062 (Japan)

    2008-05-01

    A very compact X-ray generator, 4.3 times more brilliant than can be attained by a conventional rotating-anticathode X-ray generator, has been developed using a U-shaped rotating anticathode and a high-flux electron gun with focusing bending magnet. A new type of rotating anticathode X-ray generator has been developed, in which the electron beam irradiates the inner surface of a U-shaped anticathode (Cu). A high-flux electron beam is focused on the inner surface by optimizing the shape of the bending magnet. The power of the electron beam can be increased to the point at which the irradiated part of the inner surface is melted, because a strong centrifugal force fixes the melted part on the inner surface. When the irradiated part is melted, a large amount of energy is stored as the heat of fusion, resulting in emission of X-rays 4.3 times more brilliant than can be attained by a conventional rotating anticathode. Oscillating translation of the irradiated position on the inner surface during use is expected to be very advantageous for extending the target life. A carbon film coating on the inner surface is considered to suppress evaporation of the target metal and will be an important technique in further realization of highly bright X-ray generation.

  18. A high time resolution x-ray diagnostic on the Madison Symmetric Torus.

    Science.gov (United States)

    DuBois, Ami M; Lee, John David; Almagri, Abdulgadar F

    2015-07-01

    A new high time resolution x-ray detector has been installed on the Madison Symmetric Torus (MST) to make measurements around sawtooth events. The detector system is comprised of a silicon avalanche photodiode, a 20 ns Gaussian shaping amplifier, and a 500 MHz digitizer with 14-bit sampling resolution. The fast shaping time diminishes the need to restrict the amount of x-ray flux reaching the detector, limiting the system dead-time. With a much higher time resolution than systems currently in use in high temperature plasma physics experiments, this new detector has the versatility to be used in a variety of discharges with varying flux and the ability to study dynamics on both slow and fast time scales. This paper discusses the new fast x-ray detector recently installed on MST and the improved time resolution capabilities compared to the existing soft and hard x-ray diagnostics. In addition to the detector hardware, improvements to the detector calibration and x-ray pulse identification software, such as additional fitting parameters and a more sophisticated fitting routine are discussed. Finally, initial data taken in both high confinement and standard reversed-field pinch plasma discharges are compared.

  19. A high time resolution x-ray diagnostic on the Madison Symmetric Torus

    Science.gov (United States)

    DuBois, Ami M.; Lee, John David; Almagri, Abdulgadar F.

    2015-07-01

    A new high time resolution x-ray detector has been installed on the Madison Symmetric Torus (MST) to make measurements around sawtooth events. The detector system is comprised of a silicon avalanche photodiode, a 20 ns Gaussian shaping amplifier, and a 500 MHz digitizer with 14-bit sampling resolution. The fast shaping time diminishes the need to restrict the amount of x-ray flux reaching the detector, limiting the system dead-time. With a much higher time resolution than systems currently in use in high temperature plasma physics experiments, this new detector has the versatility to be used in a variety of discharges with varying flux and the ability to study dynamics on both slow and fast time scales. This paper discusses the new fast x-ray detector recently installed on MST and the improved time resolution capabilities compared to the existing soft and hard x-ray diagnostics. In addition to the detector hardware, improvements to the detector calibration and x-ray pulse identification software, such as additional fitting parameters and a more sophisticated fitting routine are discussed. Finally, initial data taken in both high confinement and standard reversed-field pinch plasma discharges are compared.

  20. Nanosecond X-ray detector based on high resistivity ZnO single crystal semiconductor

    Science.gov (United States)

    Zhao, Xiaolong; Chen, Liang; He, Yongning; Liu, Jinliang; Peng, Wenbo; Huang, Zhiyong; Qi, Xiaomeng; Pan, Zijian; Zhang, Wenting; Zhang, Zhongbing; Ouyang, Xiaoping

    2016-04-01

    The pulse radiation detectors are sorely needed in the fields of nuclear reaction monitoring, material analysis, astronomy study, spacecraft navigation, and space communication. In this work, we demonstrate a nanosecond X-ray detector based on ZnO single crystal semiconductor, which emerges as a promising compound-semiconductor radiation detection material for its high radiation tolerance and advanced large-size bulk crystal growth technique. The resistivity of the ZnO single crystal is as high as 1013 Ω cm due to the compensation of the donor defects (VO) and acceptor defects (VZn and Oi) after high temperature annealing in oxygen. The photoconductive X-ray detector was fabricated using the high resistivity ZnO single crystal. The rise time and fall time of the detector to a 10 ps pulse electron beam are 0.8 ns and 3.3 ns, respectively, indicating great potential for ultrafast X-ray detection applications.

  1. Refractive X-ray lens for high pressure experiments at SPring-8

    CERN Document Server

    Ohishi, Y; Ishii, M; Ishikawa, T; Shimomura, O

    2001-01-01

    A stacked compound refractive X-ray lens was designed to produce an efficiently focused (phi (cursive,open) Greek<0.1 mm) beam for high-pressure experiments at SPring-8. High-pressure X-ray diffraction requires an intense, high-energy and monochromatic X-ray beam in order to penetrate the absorptive window of a diamond anvil cell (DAC). Our lens, producing a focal spot of 120x275 mu m sup 2 and a peak gain of 12, is well matched to these requirements. It is composed of many plastic chips made by molding, which allows many identical chips to be made precisely. Other advantages of this lens include high throughput, simple energy tunability and easy installation.

  2. High average power, highly brilliant laser-produced plasma source for soft X-ray spectroscopy.

    Science.gov (United States)

    Mantouvalou, Ioanna; Witte, Katharina; Grötzsch, Daniel; Neitzel, Michael; Günther, Sabrina; Baumann, Jonas; Jung, Robert; Stiel, Holger; Kanngiesser, Birgit; Sandner, Wolfgang

    2015-03-01

    In this work, a novel laser-produced plasma source is presented which delivers pulsed broadband soft X-radiation in the range between 100 and 1200 eV. The source was designed in view of long operating hours, high stability, and cost effectiveness. It relies on a rotating and translating metal target and achieves high stability through an on-line monitoring device using a four quadrant extreme ultraviolet diode in a pinhole camera arrangement. The source can be operated with three different laser pulse durations and various target materials and is equipped with two beamlines for simultaneous experiments. Characterization measurements are presented with special emphasis on the source position and emission stability of the source. As a first application, a near edge X-ray absorption fine structure measurement on a thin polyimide foil shows the potential of the source for soft X-ray spectroscopy.

  3. High-energy, high-resolution x-ray imaging for metallic cultural heritages

    Directory of Open Access Journals (Sweden)

    Masato Hoshino

    2017-10-01

    Full Text Available An x-ray micro-imaging technique to visualize high-resolution structure of cultural heritages made of iron or copper has been developed. It utilizes high-energy x-rays from a bending magnet at the SPring-8 synchrotron radiation facility. A white x-ray beam was attenuated by 0.5 mm tungsten and 2.0 mm lead absorbers resulting in the peak energy of 200 keV. The tungsten absorber eliminated the photon energy peak below the absorption edge of lead. A sample was rotated over 180 degrees in 500 s and projection images were continuously collected with an exposure time of 500 ms by an sCMOS camera equipped with a scintillator. Tomographic reconstruction of an ancient sword containing of both copper and iron was successfully obtained at a voxel size of 14.8 μm. Beam hardening was found to cause 2.5 % differences in density in a reconstructed image of a homogeneous stainless-steel rod. Ring artefacts were reduced by continuously moving the absorbers. This work demonstrates feasibility of high-energy, high-resolution imaging at a synchrotron beamline which may be generally useful for inspecting metallic objects.

  4. High-energy, high-resolution x-ray imaging for metallic cultural heritages

    Science.gov (United States)

    Hoshino, Masato; Uesugi, Kentaro; Shikaku, Ryuji; Yagi, Naoto

    2017-10-01

    An x-ray micro-imaging technique to visualize high-resolution structure of cultural heritages made of iron or copper has been developed. It utilizes high-energy x-rays from a bending magnet at the SPring-8 synchrotron radiation facility. A white x-ray beam was attenuated by 0.5 mm tungsten and 2.0 mm lead absorbers resulting in the peak energy of 200 keV. The tungsten absorber eliminated the photon energy peak below the absorption edge of lead. A sample was rotated over 180 degrees in 500 s and projection images were continuously collected with an exposure time of 500 ms by an sCMOS camera equipped with a scintillator. Tomographic reconstruction of an ancient sword containing of both copper and iron was successfully obtained at a voxel size of 14.8 μm. Beam hardening was found to cause 2.5 % differences in density in a reconstructed image of a homogeneous stainless-steel rod. Ring artefacts were reduced by continuously moving the absorbers. This work demonstrates feasibility of high-energy, high-resolution imaging at a synchrotron beamline which may be generally useful for inspecting metallic objects.

  5. High-Resolution Structure of the Photosynthetic Mn4Ca Catalyst from X-ray Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Yachandra, Vittal; Yano, Junko; Kern, Jan; Pushkar, Yulia; Sauer, Kenneth; Glatzel, Pieter; Bergmann, Uwe; Messinger, Johannes; Zouni, Athina; Yachandra, Vittal K.

    2007-08-01

    The application of high-resolution X-ray spectroscopy methods to study the photosynthetic water oxidizing complex, which contains a unique hetero-nuclear catalytic Mn4Ca cluster, are described. Issues of X-ray damage especially at the metal sites in the Mn4Ca cluster are discussed. The structure of the Mn4Ca catalyst at high-resolution which has so far eluded attempts of determination by X-ray diffraction, EXAFS and other spectroscopic techniques has been addressed using polarized EXAFS techniques applied to oriented PS II membrane preparations and PS II single crystals. A review of how the resolution of traditional EXAFS techniques can be improved, using methods such as range-extended EXAFS is presented, and the changes that occur in the structure of the cluster as it advances through the catalytic cycle are described. X-ray absorption and emission techniques (XANES and K? emission) have been used earlier to determine the oxidation states of the Mn4Ca cluster, and in this report we review the use of X-ray resonant Raman spectroscopy to understand the electronic structure of the Mn4Ca cluster as it cycles through the intermediate S-states.

  6. Cryogenic x-ray diffraction microscopy utilizing high-pressure cryopreservation

    Science.gov (United States)

    Lima, Enju; Chushkin, Yuriy; van der Linden, Peter; Kim, Chae Un; Zontone, Federico; Carpentier, Philippe; Gruner, Sol M.; Pernot, Petra

    2014-10-01

    We present cryo x-ray diffraction microscopy of high-pressure-cryofixed bacteria and report high-convergence imaging with multiple image reconstructions. Hydrated D. radiodurans cells were cryofixed at 200 MPa pressure into ˜10-μm-thick water layers and their unstained, hydrated cellular environments were imaged by phasing diffraction patterns, reaching sub-30-nm resolutions with hard x-rays. Comparisons were made with conventional ambient-pressure-cryofixed samples, with respect to both coherent small-angle x-ray scattering and the image reconstruction. The results show a correlation between the level of background ice signal and phasing convergence, suggesting that phasing difficulties with frozen-hydrated specimens may be caused by high-background ice scattering.

  7. High-energy synchrotron X-ray radiography of shock-compressed materials

    Science.gov (United States)

    Rutherford, Michael E.; Chapman, David J.; Collinson, Mark A.; Jones, David R.; Music, Jasmina; Stafford, Samuel J. P.; Tear, Gareth R.; White, Thomas G.; Winters, John B. R.; Drakopoulos, Michael; Eakins, Daniel E.

    2015-06-01

    This presentation will discuss the development and application of a high-energy (50 to 250 keV) synchrotron X-ray imaging method to study shock-compressed, high-Z samples at Beamline I12 at the Diamond Light Source synchrotron (Rutherford-Appleton Laboratory, UK). Shock waves are driven into materials using a portable, single-stage gas gun designed by the Institute of Shock Physics. Following plate impact, material deformation is probed in-situ by white-beam X-ray radiography and complimentary velocimetry diagnostics. The high energies, large beam size (13 x 13 mm), and appreciable sample volumes (~ 1 cm3) viable for study at Beamline I12 compliment existing in-house pulsed X-ray capabilities and studies at the Dynamic Compression Sector. The authors gratefully acknowledge the ongoing support of Imperial College London, EPSRC, STFC and the Diamond Light Source, and AWE Plc.

  8. X-ray reflectivity measurements of liquid/solid interfaces under high hydrostatic pressure conditions.

    Science.gov (United States)

    Wirkert, Florian J; Paulus, Michael; Nase, Julia; Möller, Johannes; Kujawski, Simon; Sternemann, Christian; Tolan, Metin

    2014-01-01

    A high-pressure cell for in situ X-ray reflectivity measurements of liquid/solid interfaces at hydrostatic pressures up to 500 MPa (5 kbar), a pressure regime that is particularly important for the study of protein unfolding, is presented. The original set-up of this hydrostatic high-pressure cell is discussed and its unique properties are demonstrated by the investigation of pressure-induced adsorption of the protein lysozyme onto hydrophobic silicon wafers. The presented results emphasize the enormous potential of X-ray reflectivity studies under high hydrostatic pressure conditions for the in situ investigation of adsorption phenomena in biological systems.

  9. The peculiar high-mass X-ray binary 1ES 1210-646

    Science.gov (United States)

    Masetti, N.; Landi, R.; Sguera, V.; Capitanio, F.; Bassani, L.; Bazzano, A.; Bird, A. J.; Malizia, A.; Palazzi, E.

    2010-02-01

    Using data collected with the BeppoSAX, INTEGRAL and Swift satellites, we report and discuss the results of a study on the X-ray emission properties of the X-ray source 1ES 1210-646, recently classified as a high-mass X-ray binary through optical spectroscopy. This is the first in-depth analysis of the X-ray spectral characteristics of this source. We found that the flux of 1ES 1210-646 varies by a factor of ~3 on a timescale of hundreds of seconds and by a factor of at least 10 among observations acquired over a time span of several months. The X-ray spectrum of 1ES 1210-646 is described using a simple powerlaw shape or, in the case of INTEGRAL data, with a blackbody plus powerlaw model. Spectral variability is found in connection with different flux levels of the source. A strong and transient iron emission line with an energy of ~6.7 keV and an equivalent width of ~1.6 keV is detected when the source is found at an intermediate flux level. The line strength seems to be tied to the orbital motion of the accreting object, as this feature is only apparent at the periastron. Although the X-ray spectral description we find for the 1ES 1210-646 emission is quite atypical for a high-mass X-ray binary, the multiwavelegth information available for this object leads us to confirm this classification. The results presented here allow us instead to definitely rule out the possibility that 1ES 1210-646 is a (magnetic) cataclysmic variable as proposed previously and, in a broader sense, a white dwarf nature for the accretor is disfavoured. X-ray spectroscopic data actually suggest a neutron star with a low magnetic field as the accreting object in this system. Partly based on X-ray observations with INTEGRAL, an ESA project with instruments and science data centre funded by ESA member states (especially the PI countries: Denmark, France, Germany, Italy, Switzerland, Spain), Czech Republic and Poland, and with the participation of Russia and the USA.

  10. A vacuum double-crystal spectrometer for reference-free highly charged ions X-ray spectroscopy

    CERN Document Server

    Amaro, P; Schlesser, S; Gumberidze, Alexandre; Kessler, Ernest G; Henins, Albert; Bigot, E -O Le; Trassinelli, M; Isac, Jean-Michel; Travers, Pascal; Guerra, Mauro; Santos, J P; Indelicato, Paul

    2012-01-01

    We have built a vacuum double crystal spectrometer, which coupled to an electron-cyclotron resonance ion source, allows to measure low-energy x-ray transitions in highly-charged ions with accuracies of the order of a few parts per million. We describe in detail the instrument and its performances. Furthermore, we present a few spectra of transitions in Ar$^{14+}$, Ar$^{15+}$ and Ar$^{16+}$. We have developed an \\emph{ab initio} simulation code that allows us to obtain accurate line profiles. It can reproduce experimental spectra with unprecedented accuracy. The quality of the profiles allows the direct determination of line width.

  11. The Astro-H High Resolution Soft X-Ray Spectrometer

    Science.gov (United States)

    Kelley, Richard L.; Akamatsu, Hiroki; Azzarell, Phillip; Bialas, Tom; Boyce, Kevin R.; Brown, Gregory V.; Canavan, Edgar; Chiao, Meng P.; Costantini, Elisa; DiPirro, Michael J.; hide

    2016-01-01

    We present the overall design and performance of the Astro-H (Hitomi) Soft X-Ray Spectrometer (SXS). The instrument uses a 36-pixel array of x-ray microcalorimeters at the focus of a grazing-incidence x-ray mirror Soft X-Ray Telescope (SXT) for high-resolution spectroscopy of celestial x-ray sources. The instrument was designed to achieve an energy resolution better than 7 eV over the 0.3-12 keV energy range and operate for more than 3 years in orbit. The actual energy resolution of the instrument is 4-5 eV as demonstrated during extensive ground testing prior to launch and in orbit. The measured mass flow rate of the liquid helium cryogen and initial fill level at launch predict a lifetime of more than 4 years assuming steady mechanical cooler performance. Cryogen-free operation was successfully demonstrated prior to launch. The successful operation of the SXS in orbit, including the first observations of the velocity structure of the Perseus cluster of galaxies, demonstrates the viability and power of this technology as a tool for astrophysics.

  12. A curved image-plate detector system for high-resolution synchrotron X-ray diffraction.

    Science.gov (United States)

    Sarin, P; Haggerty, R P; Yoon, W; Knapp, M; Berghaeuser, A; Zschack, P; Karapetrova, E; Yang, N; Kriven, W M

    2009-03-01

    The developed curved image plate (CIP) is a one-dimensional detector which simultaneously records high-resolution X-ray diffraction (XRD) patterns over a 38.7 degrees 2theta range. In addition, an on-site reader enables rapid extraction, transfer and storage of X-ray intensity information in response is not compromised in the unsaturated regions of the image plate, regardless of saturation in another region. The speed of XRD data acquisition together with excellent resolution afforded by the CIP detector is unique and opens up wide possibilities in materials research accessible through X-ray diffraction. This article presents details of the basic features, operation and performance of the CIP detector along with some examples of applications, including high-temperature XRD.

  13. Phase contrast enhanced high resolution X-ray imaging and tomography of soft tissue

    Energy Technology Data Exchange (ETDEWEB)

    Jakubek, Jan [Institute of Experimental and Applied Physis, Czech Technical Universtiy in Prague, Horska 3a/22, 128 00 Prague 2 (Czech Republic); Granja, Carlos [Institute of Experimental and Applied Physis, Czech Technical Universtiy in Prague, Horska 3a/22, 128 00 Prague 2 (Czech Republic)]. E-mail: carlos.granja@utef.cvut.cz; Dammer, Jiri [Institute of Experimental and Applied Physis, Czech Technical Universtiy in Prague, Horska 3a/22, 128 00 Prague 2 (Czech Republic); Hanus, Robert [Institute of Organic Chemistry and Biochemistry, Academy of Sciences, CZ-166 10 Prague 6 (Czech Republic); Holy, Tomas [Institute of Experimental and Applied Physis, Czech Technical Universtiy in Prague, Horska 3a/22, 128 00 Prague 2 (Czech Republic); Pospisil, Stanislav [Institute of Experimental and Applied Physis, Czech Technical Universtiy in Prague, Horska 3a/22, 128 00 Prague 2 (Czech Republic); Tykva, Richard [Institute of Organic Chemistry and Biochemistry, Academy of Sciences, CZ-166 10 Prague 6 (Czech Republic); Uher, Josef [Institute of Experimental and Applied Physis, Czech Technical Universtiy in Prague, Horska 3a/22, 128 00 Prague 2 (Czech Republic); Vykydal, Zdenek [Institute of Experimental and Applied Physis, Czech Technical Universtiy in Prague, Horska 3a/22, 128 00 Prague 2 (Czech Republic)

    2007-02-01

    A tabletop system for digital high resolution and high sensitivity X-ray micro-radiography has been developed for small-animal and soft-tissue imaging. The system is based on a micro-focus X-ray tube and the semiconductor hybrid position sensitive Medipix2 pixel detector. Transmission radiography imaging, conventionally based only on absorption, is enhanced by exploiting phase-shift effects induced in the X-ray beam traversing the sample. Phase contrast imaging is realized by object edge enhancement. DAQ is done by a novel fully integrated USB-based readout with online image generation. Improved signal reconstruction techniques make use of advanced statistical data analysis, enhanced beam hardening correction and direct thickness calibration of individual pixels. 2D and 3D micro-tomography images of several biological samples demonstrate the applicability of the system for biological and medical purposes including in-vivo and time dependent physiological studies in the life sciences.

  14. Soft x-ray nanoscale imaging using highly brilliant laboratory sources and new detector concepts

    Science.gov (United States)

    Stiel, H.; Braenzel, J.; Dehlinger, A.; Jung, R.; Luebcke, A.; Regehly, M.; Ritter, S.; Tuemmler, J.; Schnuerer, M.; Seim, C.

    2017-05-01

    In this contribution, we report about nanoscale imaging using a laser produced plasma source based laboratory transmission X-ray microscope (LTXM) in the water window. The highly brilliant soft X-ray radiation of the LTXM is provided by a laser-produced nitrogen plasma source focused by a multilayer condenser mirror to the sample. An objective zone plate maps the magnified image of the sample on the super resolution camera. This camera employs a deep cooled soft-X-ray CCD imaging sensor sandwiched with a xy piezo stage to allow subpixel displacements of the detector. The camera is read out using a very low noise electronics platform, also directing low µm shifts of the sensor between subsequent image acquisitions. Finally an algorithm computes a high resolution image from the individual shifted low-resolution image frames.

  15. The HERO Program: High-Energy Replicated Optics for a Hard-X-Ray Balloon Payload

    Science.gov (United States)

    Ramsey, B. D.; Engelhaupt, D.; Speegle, C. O.; Austin, R. A.; Kolodziejczak, J. J.; ODell, S. L.; Weisskopf, M. C.

    1999-01-01

    We are developing high-energy replicated optics for a balloon-borne hard-x-ray telescope. When completed, the telescope will have around 150 square cm of effective collecting area up to 65 keV, and an angular resolution of around 30 arc seconds, half power diameter. When used in conjunction with an array of focal plane imaging detectors, for which Gas Scintillation Proportional Counters are under development, the payload will provide unprecedented sensitivity for pointed observations in the hard-x-ray band. We will present an overview of the High Energy Replicated Optics (HERO) program together with test data from the first mirror units. The overall sensitivity of the full payload, when flown on long- and ultra-long-duration balloon flights, will be compared with past and planned satellite-borne hard-x-ray missions.

  16. Diagnostic accuracy of full-body linear X-ray scanning in multiple trauma patients in comparison to computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Joeres, A.P.W.; Heverhagen, J.T.; Bonel, H. [Inselspital - University Hospital Bern (Switzerland). Univ. Inst. of Diagnostic, Interventional and Pediatric Radiology; Exadaktylos, A. [Inselspital - University Hospital Bern (Switzerland). Dept. of Emergency Medicine; Klink, T. [Inselspital - University Hospital Bern (Switzerland). Univ. Inst. of Diagnostic, Interventional and Pediatric Radiology; Wuerzburg Univ. (Germany). Inst. of Diagnostic and Interventional Radiology

    2016-02-15

    The purpose of this study was to evaluate the diagnostic accuracy of full-body linear X-ray scanning (LS) in multiple trauma patients in comparison to 128-multislice computed tomography (MSCT). 106 multiple trauma patients (female: 33; male: 73) were retrospectively included in this study. All patients underwent LS of the whole body, including extremities, and MSCT covering the neck, thorax, abdomen, and pelvis. The diagnostic accuracy of LS for the detection of fractures of the truncal skeleton and pneumothoraces was evaluated in comparison to MSCT by two observers in consensus. Extremity fractures detected by LS were documented. The overall sensitivity of LS was 49.2%, the specificity was 93.3%, the positive predictive value was 91%, and the negative predictive value was 57.5%. The overall sensitivity for vertebral fractures was 16.7%, and the specificity was 100%. The sensitivity was 48.7% and the specificity 98.2% for all other fractures. Pneumothoraces were detected in 12 patients by CT, but not by LS.40 extremity fractures were detected by LS, of which 4 fractures were dislocated, and 2 were fully covered by MSCT. The diagnostic accuracy of LS is limited in the evaluation of acute trauma of the truncal skeleton. LS allows fast whole-body X-ray imaging, and may be valuable for detecting extremity fractures in trauma patients in addition to MSCT.

  17. Fabrication of high-aspect-ratio hard x-ray zone plates with HSQ plating molds

    Science.gov (United States)

    Lu, Ming; Ocola, Leonidas E.; Divan, Ralu; Mancini, Derrick C.

    2008-08-01

    Fresnel zone plates are important x-ray diffractive optics which offer a focusing resolution approaching the theoretical limit. In hard x-ray region, the refractive indices of all the materials are close to unity, which requests thick zone plate to achieve a reasonable efficiency. It makes high-resolution zone plate extremely difficult to fabricate due to its high aspect ratio. We report a LIGA-like fabrication process employing e-beam resist HSQ as the plating mold material, which is relative simply compared with traditional processes. 1-μm-thick gold zone plates with 80-nm-wide outermost zone have been fabricated with this process.

  18. X-ray spectroscopy of highly-charged heavy ions at FAIR

    Energy Technology Data Exchange (ETDEWEB)

    Gumberidze, A. [Laboratoire Kastler Brossel, Universite P. et M. Curie, Paris (France)], E-mail: a.gumberidze@gsi.de; Stoehlker, Th. [Gesellschaft fur Schwerionenforschung mbh, 64291 GSI-Darmstadt (Germany); Physikalisches Institut, Universitt Heidelberg, D-69120 Heidelberg (Germany); Beyer, H.F.; Bosch, F.; Braeuning-Demian, A.; Hagmann, S.; Kozhuharov, C.; Kuehl, Th.; Mann, R. [Gesellschaft fur Schwerionenforschung mbh, 64291 GSI-Darmstadt (Germany); Indelicato, P. [Laboratoire Kastler Brossel, Universite P. et M. Curie, Paris (France); Quint, W. [Gesellschaft fur Schwerionenforschung mbh, 64291 GSI-Darmstadt (Germany); Schuch, R. [Stockholm University, Stockholm (Sweden); Warczak, A. [Institute of Physics, Jagiellonian University, Cracow (Poland)

    2009-01-15

    In the current contribution, we give an overview of the envisioned X-ray spectroscopy program within the atomic physics research collaboration SPARC (Stored Particle Atomic Research Collaboration) at FAIR (Facility for Antiproton and Ion Research). These activities comprise, among others, the investigation of relativistic collision dynamics, electron correlation in the presence of strong fields, the test of Quantum Electrodynamics in extremely strong electromagnetic fields, and ideas to test the predictions of fundamental theories besides Quantum Electrodynamics. The state of the art X-ray spectroscopy will be of key importance for realization of these challenging goals. The world-wide unique experimental conditions and opportunities offered by the future FAIR facility will be combined with advanced X-ray detection devices, i.e. large-area, segmented solid-state detectors, high-resolution crystal spectrometers, calorimetric detectors etc.

  19. High-pressure x-ray absorption spectroscopy study of tin tungstates

    Science.gov (United States)

    Kuzmin, A.; Anspoks, A.; Kalinko, A.; Timoshenko, J.; Kalendarev, R.; Nataf, L.; Baudelet, F.; Irifune, T.

    2015-09-01

    Room-temperature pressure-dependent (0-25 GPa) x-ray absorption spectroscopy at the W {L}{1,3}-edges of α-SnWO4 and β-SnWO4 was performed using a dispersive setup and a high-pressure nanodiamond anvil cell. The detailed analysis of experimental x-ray absorption near-edge structure and extended x-ray absorption fine structure data suggests that upon increasing pressure, a displacement of tungsten atoms by about 0.2 Å toward the center of the WO6 octahedra occurs in α-SnWO4, whereas the coordination of tungsten atoms changes from tetrahedral to distorted octahedral in β-SnWO4.

  20. Simulation of high-resolution X-ray microscopic images for improved alignment

    Energy Technology Data Exchange (ETDEWEB)

    Song Xiangxia; Zhang Xiaobo; Liu Gang; Cheng Xianchao; Li Wenjie; Guan Yong; Liu Ying; Xiong Ying [National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, Anhui 230029 (China); Tian Yangchao, E-mail: ychtian@ustc.edu.cn [National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, Anhui 230029 (China)

    2011-12-11

    The introduction of precision optical elements to X-ray microscopes necessitates fine realignment to achieve optimal high-resolution imaging. In this paper, we demonstrate a numerical method for simulating image formation that facilitates alignment of the source, condenser, objective lens, and CCD camera. This algorithm, based on ray-tracing and Rayleigh-Sommerfeld diffraction theory, is applied to simulate the X-ray microscope beamline U7A of National Synchrotron Radiation Laboratory (NSRL). The simulations and imaging experiments show that the algorithm is useful for guiding experimental adjustments. Our alignment simulation method is an essential tool for the transmission X-ray microscope (TXM) with optical elements and may also be useful for the alignment of optical components in other modes of microscopy.

  1. Preliminary investigation of changes in x-ray multilayer optics subjected to high radiation flux

    Energy Technology Data Exchange (ETDEWEB)

    Hockaday, M.P.; Blake, R.L.; Grosso, J.S.; Selph, M.M.; Klein, M.M.; Matuska, W. Jr.; Palmer, M.A.; Liefeld, R.J.

    1985-01-01

    A variety of metal multilayers was exposed to high x-ray flux using Sandia National Laboratories' PROTO II machine in the gas puff mode. Fluxes incident on the multilayers above 700 MW/cm/sup 2/ in total radiation, in nominal 20 ns pulses, were realized. The neon hydrogen- and helium-like resonance lines were used to probe the x-ray reflectivity properties of the multilayers as they underwent change of state during the heating pulse. A fluorescer-fiber optic-streak camera system was used to monitor the changes in x-ray reflectivity as a function of time and irradiance. Preliminary results are presented for a W/C multilayer. Work in progress to model the experiment is discussed. 13 refs., 4 figs.

  2. High-efficiency logarithmic spiral monochromator for X-ray fluorescence

    CERN Document Server

    Bakulin, A S

    2000-01-01

    A spiral mosaic crystal monochromator system has been designed for high-efficiency collection of X-ray fluorescence. This is especially well suited for X-ray holography measurements, where a weak fluorescence signal must be separated from a strong background. Calculations show that pyrolytic graphite curved to a logarithmic spiral has a dramatically increased angular acceptance compared to standard graphite monochromator designs. The collection efficiency per unit area of graphite is improved by a factor of 200 compared to sagittal focusing geometries, while maintaining the intrinsic graphite energy resolution.

  3. Development of high-resolution x-ray CT system using parallel beam geometry

    Energy Technology Data Exchange (ETDEWEB)

    Yoneyama, Akio, E-mail: akio.yoneyama.bu@hitachi.com; Baba, Rika [Central Research Laboratory, Hitachi Ltd., Hatoyama, Saitama (Japan); Hyodo, Kazuyuki [Institute of Materials Science, High Energy Accelerator Research Organization, Tsukuba, Ibaraki (Japan); Takeda, Tohoru [School of Allied Health Sciences, Kitasato University, Sagamihara, Kanagawa (Japan); Nakano, Haruhisa; Maki, Koutaro [Department of Orthodontics, School of Dentistry Showa University, Ota-ku, Tokyo (Japan); Sumitani, Kazushi; Hirai, Yasuharu [Kyushu Synchrotron Light Research Center, Tosu, Saga (Japan)

    2016-01-28

    For fine three-dimensional observations of large biomedical and organic material samples, we developed a high-resolution X-ray CT system. The system consists of a sample positioner, a 5-μm scintillator, microscopy lenses, and a water-cooled sCMOS detector. Parallel beam geometry was adopted to attain a field of view of a few mm square. A fine three-dimensional image of birch branch was obtained using a 9-keV X-ray at BL16XU of SPring-8 in Japan. The spatial resolution estimated from the line profile of a sectional image was about 3 μm.

  4. Picosecond X-ray radiography of superdense high-temperature laser plasma

    Science.gov (United States)

    Andreev, A. A.; Bel'kov, S. A.; Platonov, K. Yu.; Romanov, V. V.; Rogozhnikov, G. S.

    2017-09-01

    The layout of an X-ray source for diagnostics of the compressed state of laser plasma is proposed, and its optimal parameters are calculated under the conditions required for nuclear fusion. Such a source operating in a pulsed regime is intended to be used for determining the spatial distribution of laser-plasma density with high temporal resolution by means of multiframe (pulses follow with a specified time interval) backlight imaging of the main target by X-ray pulses obtained by irradiation of a secondary target by picosecond laser pulses.

  5. X-ray observations of the 1980 Cygnus X-1 'high state'

    Science.gov (United States)

    Ogawara, Y.; Mitsuda, K.; Masai, K.; Vallerga, J. V.; Cominsky, L. R.; Grunsfeld, J. M.; Kruper, J. S.; Ricker, G. R.

    1982-01-01

    Observations of intensity transitions in the X-ray emission from the black-hole candidate Cygnus X-1 were made by the Hakucho satellite during the summer of 1980 and are reported here. In addition, the results of hard (20-120 keV) X-ray observations of Cyg X-1 are reported. These data were obtained during the 'high' intensity state by balloon-borne mercuric iodide detectors, and are compared with data obtained at similar energies approximately 1 month earlier (A. Sheepmaker et al., in preparation) during the 'low' intensity state.

  6. High power laser pulse circulation experiment for compact quasi-monochromatic tunable X-ray source

    Energy Technology Data Exchange (ETDEWEB)

    Meng, De [Nuclear Professional School, University of Tokyo, 2-22 Shirakata-Shirane, Tokai, Naka, Ibaraki 319-1188 (Japan)]. E-mail: dmou@nuclear.jp; Sakamoto, Fumito [Nuclear Professional School, University of Tokyo, 2-22 Shirakata-Shirane, Tokai, Naka, Ibaraki 319-1188 (Japan); Yamamoto, Tomohiko [Nuclear Professional School, University of Tokyo, 2-22 Shirakata-Shirane, Tokai, Naka, Ibaraki 319-1188 (Japan); Dobashi, Katsuhiro [Nuclear Professional School, University of Tokyo, 2-22 Shirakata-Shirane, Tokai, Naka, Ibaraki 319-1188 (Japan); Uesaka, Mitsuru [Nuclear Professional School, University of Tokyo, 2-22 Shirakata-Shirane, Tokai, Naka, Ibaraki 319-1188 (Japan); Nose, Hiroyuki [Ishikawajima-Harima Heavy Industries Co., Ltd., Toyosu Ihi Building, 1-1, Toyosu 3-chome, Koto-ku, Tokyo 135-8710 (Japan); Ishida, Daisuke [Ishikawajima-Harima Heavy Industries Co., Ltd., Toyosu Ihi Building, 1-1, Toyosu 3-chome, Koto-ku, Tokyo 135-8710 (Japan); Kaneko, Namio [Ishikawajima-Harima Heavy Industries Co., Ltd., Toyosu Ihi Building, 1-1, Toyosu 3-chome, Koto-ku, Tokyo 135-8710 (Japan); Sakai, Yasuo [Ishikawajima-Harima Heavy Industries Co., Ltd., Toyosu Ihi Building, 1-1, Toyosu 3-chome, Koto-ku, Tokyo 135-8710 (Japan)

    2007-08-15

    Laser electron Compton scattering monochromatic tunable X-ray source using X-band (11.424 GHz) electron linear accelerator and Q-switch Nd:YAG laser is under construction at Nuclear Professional School, University of Tokyo. To enhance the X-ray intensity, we installed a laser circulation system. Now, we are performing the circulation experiment by using a high power laser (1.4 J, 532 nm). We confirmed the laser pulse circulated in the optical circuit more than 15 times and the laser intensity is enhanced about 3.5 times.

  7. High resolution x-ray fluorescence spectroscopy - a new technique for site- and spin-selectivity

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Xin [Univ. of California, Davis, CA (United States). Dept. of Applied Science

    1996-12-01

    X-ray spectroscopy has long been used to elucidate electronic and structural information of molecules. One of the weaknesses of x-ray absorption is its sensitivity to all of the atoms of a particular element in a sample. Through out this thesis, a new technique for enhancing the site- and spin-selectivity of the x-ray absorption has been developed. By high resolution fluorescence detection, the chemical sensitivity of K emission spectra can be used to identify oxidation and spin states; it can also be used to facilitate site-selective X-ray Absorption Near Edge Structure (XANES) and site-selective Extended X-ray Absorption Fine Structure (EXAFS). The spin polarization in K fluorescence could be used to generate spin selective XANES or spin-polarized EXAFS, which provides a new measure of the spin density, or the nature of magnetic neighboring atoms. Finally, dramatic line-sharpening effects by the combination of absorption and emission processes allow observation of structure that is normally unobservable. All these unique characters can enormously simplify a complex x-ray spectrum. Applications of this novel technique have generated information from various transition-metal model compounds to metalloproteins. The absorption and emission spectra by high resolution fluorescence detection are interdependent. The ligand field multiplet model has been used for the analysis of K{alpha} and K{beta} emission spectra. First demonstration on different chemical states of Fe compounds has shown the applicability of site selectivity and spin polarization. Different interatomic distances of the same element in different chemical forms have been detected using site-selective EXAFS.

  8. Diffractometer for high energy X-rays at the APS

    CERN Document Server

    Rütt, U; Strempfer, J; Jennings, G; Kurtz, C; Montano, P A

    2001-01-01

    The Basic Energy Sciences Synchrotron Radiation Center (BESSRC) has designed and built a diffractometer specialized for high energy synchrotron radiation (E>60 keV) at the Advanced Photon Source (APS). The diffractometer, which is installed at the elliptical multipole wiggler, uses linearly polarized light (U. Ruett et al., Proc. SPIE 3348 (1998) 132.). The instrument is a triple-axis diffractometer allowing high resolution measurement in two dimensions of the reciprocal space. As opposed to the other diffractometers for high photon energies at HASYLAB (Germany) and ESRF (France) (R. Bouchard et al., 5 (1998) 90; K.-D. Liss et al., J. Synchrotron Rad. 5 (1998) 82), this diffractometer utilizes the vertical scattering plane to take full advantage of the small vertical divergence of the beam and to allow horizontal focusing of the broad beam from the wiggler without disturbing the resolution of the instrument. The instrument is designed to carry heavy sample equipment up to a weight of 200 kg, while maintaining...

  9. Geometric and dosimetric accuracy of dynamic tumor-tracking conformal arc irradiation with a gimbaled x-ray head.

    Science.gov (United States)

    Ono, Tomohiro; Miyabe, Yuki; Yamada, Masahiro; Shiinoki, Takehiro; Sawada, Akira; Kaneko, Shuji; Monzen, Hajime; Mizowaki, Takashi; Kokubo, Masaki; Hiraoka, Masahiro

    2014-03-01

    The Vero4DRT system has the capability for dynamic tumor-tracking (DTT) stereotactic irradiation using a unique gimbaled x-ray head. The purposes of this study were to develop DTT conformal arc irradiation and to estimate its geometric and dosimetric accuracy. The gimbaled x-ray head, supported on an O-ring gantry, was moved in the pan and tilt directions during O-ring gantry rotation. To evaluate the mechanical accuracy, the gimbaled x-ray head was moved during the gantry rotating according to input command signals without a target tracking, and a machine log analysis was performed. The difference between a command and a measured position was calculated as mechanical error. To evaluate beam-positioning accuracy, a moving phantom, which had a steel ball fixed at the center, was driven based on a sinusoidal wave (amplitude [A]: 20 mm, time period [T]: 4 s), a patient breathing motion with a regular pattern (A: 16 mm, average T: 4.5 s), and an irregular pattern (A: 7.2-23.0 mm, T: 2.3-10.0 s), and irradiated with DTT during gantry rotation. The beam-positioning error was evaluated as the difference between the centroid position of the irradiated field and the steel ball on images from an electronic portal imaging device. For dosimetric accuracy, dose distributions in static and moving targets were evaluated with DTT conformal arc irradiation. The root mean squares (RMSs) of the mechanical error were up to 0.11 mm for pan motion and up to 0.14 mm for tilt motion. The RMSs of the beam-positioning error were within 0.23 mm for each pattern. The dose distribution in a moving phantom with tracking arc irradiation was in good agreement with that in static conditions. The gimbal positional accuracy was not degraded by gantry motion. As in the case of a fixed port, the Vero4DRT system showed adequate accuracy of DTT conformal arc irradiation.

  10. Affordable and lightweight high-resolution x-ray optics for astronomical missions

    Science.gov (United States)

    Zhang, W. W.; Biskach, M. P.; Bly, V. T.; Carter, J. M.; Chan, K. W.; Gaskin, J. A.; Hong, M.; Hohl, B. R.; Jones, W. D.; Kolodziejczak, J. J.; Kolos, L. D.; Mazzarella, J. R.; McClelland, R. S.; McKeon, K. P.; Miller, T. M.; O'Dell, S. L.; Riveros, R. E.; Saha, T. T.; Schofield, M. J.; Sharpe, M. V.; Smith, H. C.

    2014-07-01

    Future x-ray astronomical missions require x-ray mirror assemblies that provide both high angular resolution and large photon collecting area. In addition, as x-ray astronomy undertakes more sensitive sky surveys, a large field of view is becoming increasingly important as well. Since implementation of these requirements must be carried out in broad political and economical contexts, any technology that meets these performance requirements must also be financially affordable and can be implemented on a reasonable schedule. In this paper we report on progress of an x-ray optics development program that has been designed to address all of these requirements. The program adopts the segmented optical design, thereby is capable of making both small and large mirror assemblies for missions of any size. This program has five technical elements: (1) fabrication of mirror substrates, (2) coating, (3) alignment, (4) bonding, and (5) mirror module systems engineering and testing. In the past year we have made progress in each of these five areas, advancing the angular resolution of mirror modules from 10.8 arc-seconds half-power diameter reported (HPD) a year ago to 8.3 arc-seconds now. These mirror modules have been subjected to and passed all environmental tests, including vibration, acoustic, and thermal vacuum. As such this technology is ready for implementing a mission that requires a 10-arc-second mirror assembly. Further development in the next two years would make it ready for a mission requiring a 5-arc-second mirror assembly. We expect that, by the end of this decade, this technology would enable the x-ray astrophysical community to compete effectively for a major x-ray mission in the 2020s that would require one or more 1-arc-second mirror assemblies for imaging, spectroscopic, timing, and survey studies.

  11. Affordable and Lightweight High-Resolution X-ray Optics for Astronomical Missions

    Science.gov (United States)

    Zhang, W. W.; Biskach, M. P.; Bly, V. T.; Carter, J. M.; Chan, K. W.; Gaskin, J. A.; Hong, M.; Hohl, B. R.; Jones, W. D.; Kolodziejczak, J. J.

    2014-01-01

    Future x-ray astronomical missions require x-ray mirror assemblies that provide both high angular resolution and large photon collecting area. In addition, as x-ray astronomy undertakes more sensitive sky surveys, a large field of view is becoming increasingly important as well. Since implementation of these requirements must be carried out in broad political and economical contexts, any technology that meets these performance requirements must also be financially affordable and can be implemented on a reasonable schedule. In this paper we report on progress of an x-ray optics development program that has been designed to address all of these requirements. The program adopts the segmented optical design, thereby is capable of making both small and large mirror assemblies for missions of any size. This program has five technical elements: (1) fabrication of mirror substrates, (2) coating, (3) alignment, (4) bonding, and (5) mirror module systems engineering and testing. In the past year we have made progress in each of these five areas, advancing the angular resolution of mirror modules from 10.8 arc-seconds half-power diameter reported (HPD) a year ago to 8.3 arc-seconds now. These mirror modules have been subjected to and passed all environmental tests, including vibration, acoustic, and thermal vacuum. As such this technology is ready for implementing a mission that requires a 10-arc-second mirror assembly. Further development in the next two years would make it ready for a mission requiring a 5-arc-second mirror assembly. We expect that, by the end of this decade, this technology would enable the x-ray astrophysical community to compete effectively for a major x-ray mission in the 2020s that would require one or more 1-arc-second mirror assemblies for imaging, spectroscopic, timing, and survey studies.

  12. High resolution X-ray spectroscopy in light antiprotonic atoms

    CERN Document Server

    Borchert, G L; Augsburger, M A; Castelli, C M; Chatellard, D; Egger, J P; El-Khoury, P; Elble, M; Gorke, H; Gotta, D; Hauser, P R; Indelicato, P J; Kirch, K; Lenz, S; Nelms, N; Rashid, K; Schult, O W B; Siems, T; Simons, L M

    2000-01-01

    At the LEAR facility, CERN, antiprotonic L alpha transitions in light elements have been investigated with a focussing crystal spectrometer. The high resolution of the experiment allowed for the first time to resolve in pH/pH the 2/sup 3/P/sub 0/ state from the close-lying states 2/sup 3/P/sub 2/, 2/sup 1/P/sub 1/, and 2/sup 3/P /sub 1/. In pD the corresponding transitions were found to be more than an order of magnitude broader. To a large extent the results for pH support the meson exchange model. (15 refs).

  13. A compact high-resolution X-ray powder diffractometer.

    Science.gov (United States)

    Fewster, Paul F; Trout, David R D

    2013-12-01

    A new powder diffractometer operating in transmission mode is described. It can work as a rapid very compact instrument or as a high-resolution instrument, and the sample preparation is simplified. The incident beam optics create pure Cu K α 1 radiation, giving rise to peak widths of ∼0.1° in 2θ in compact form with a sample-to-detector minimum radius of 55 mm, reducing to peak widths of advantage of this geometry is that the resolution of the diffractometer can be calculated precisely and the instrumental artefacts can be analysed easily without a sample present. The performance is demonstrated with LaB 6 and paracetamol, and a critical appraisal of the uncertainties in the measurements is presented. The instantaneous data collection offers possibilities in dynamic experiments.

  14. High energy x-ray and neutron studies of disordered energy-related materials at extreme conditions

    Energy Technology Data Exchange (ETDEWEB)

    Parise, John [Stony Brook Univ., NY (United States)

    2016-05-16

    The fundamental scientific accomplishments are: (1) advances in a general description of the liquid state by employing structural models constrained by measurements to interpret experimental results and extend them to liquids in general, with special emphasis on (2) The structure of the high-temperature crystal and molten UO2 and 3) water. Specifically, samples of UO2 and water were probed using high-energy x-rays at the Advanced Photon Source. The high Z of UO2, and the 2-3mm diameter droplet shape of the molten sample, means that >100keV X-rays are required to minimize absorption and multiple scattering, which can distort the measured structure factor. A high flux of x-rays is also required to obtain sufficient statistical accuracy in short (a few seconds) measurement times. The scattered x-ray data were analyzed and pair distribution functions, extracted that characterize the local and long-range atomic structure of the material. The measurements of the hot UO2 solid show a substantial increase in oxygen disorder and, upon melting, the average U-O coordination was found to decrease from 8 to 6.7±0.5. The research incorporated development of diffraction techniques, sample environment optimization and state-of-the-art simulation techniques. The symbiotic nature of the advances in simulation and experiment allowed for a more focused and informed development of future experiments, effective use of expensive beam time and generated new research agendas for the growing number of research groups, within the US and internationally, that focus on the structure of liquids. Molecular dynamics (MD) provided detailed information when combined with high-quality XN data including addressing key issues in liquids; the relationship between cooling path, structure and fictive temperature, and the trade-offs between network over connectedness in liquids containing low-coordination cations.

  15. High spatial resolution X-ray and gamma ray imaging system using diffraction crystals

    Science.gov (United States)

    Smither, Robert K [Hinsdale, IL

    2011-05-17

    A method and a device for high spatial resolution imaging of a plurality of sources of x-ray and gamma-ray radiation are provided. The device comprises a plurality of arrays, with each array comprising a plurality of elements comprising a first collimator, a diffracting crystal, a second collimator, and a detector.

  16. Constraining omega from X-ray properties of clusters of galaxies at high redshifts

    DEFF Research Database (Denmark)

    Sadat, R.; Blanchard, A.; Oukbir, J.

    1997-01-01

    Properties of high redshift clusters are a fundamental source of information for cosmology. It has been shown by Oukbir and Blanchard (1997) that the combined knowledge of the redshift distribution of X-ray clusters of galaxies and the luminosity-temperature correlation, L-X - T-X, provides a pow...

  17. High-speed X-ray imaging of a ball impacting on loose sand

    NARCIS (Netherlands)

    Homan, T.A.M.; Mudde, R.F.; Lohse, Detlef; van der Meer, Roger M.

    2015-01-01

    When a ball is dropped in fine very loose sand, a splash and subsequently a jet are observed above the bed, followed by a granular eruption. To directly and quantitatively determine what happens inside the sand bed, high-speed X-ray tomography measurements are carried out in a custom-made set-up

  18. High energy X-ray spectrometer on the Chandrayaan-1 mission to ...

    Indian Academy of Sciences (India)

    The Chandrayaan-1 mission to the Moon scheduled for launch in late 2007 will include a high energy X-ray spectrometer (HEX) for detection of naturally occurring emissions from the lunar surface due to radioactive decay of ... Space Astronomy and Instrumentation Division, ISRO Satellite Center, Bangalore 560 017, India.

  19. High resolution X-ray scattering studies of substrates and multilayers

    DEFF Research Database (Denmark)

    Christensen, Finn Erland

    1988-01-01

    High resolution X-ray scattering measurements on multilayer substrates and surfaces are reviewed. It is shown that the usual substrates of float glass and Si-wafers are dominated by large scale figure error, whereas samples of super polished SiC substrates are comparable in flatness and roughness...

  20. High-pressure x-ray diffraction of icosahedral Zr-Al-Ni-Cu-Ag quasicrystals

    DEFF Research Database (Denmark)

    Jiang, Jianzhong; Saksl, Karel; Rasmussen, Helge Kildahl

    2001-01-01

    The effect of pressure on the structural stability of icosahedral Zr-Al-Ni-Cu-Ag quasicrystals forming from a Zr65Al7.5Ni10Cu7.5Ag10 metallic glass with a supercooled liquid region of 44 K has been investigated by in situ high-pressure angle-dispersive x-ray powder diffraction at ambient temperat...

  1. High Pressure X-ray Absorption Studies on Correlated-Electron Systems

    Energy Technology Data Exchange (ETDEWEB)

    Cornelius, Andrew L. [Univ. of Nevada, Las Vegas, NV (United States)

    2016-08-26

    This project used high pressure to alter the electron-electron and electron-lattice interactions in rare earth and actinide compounds. Knowledge of these properties is the starting points for a first-principles understanding of electronic and electronically related macroscopic properties. The research focused on a systematic study of x-ray absorption measurements on rare earth and actinide compounds.

  2. Evaluation of high packing density powder X-ray screens by Monte Carlo methods

    Science.gov (United States)

    Liaparinos, P.; Kandarakis, I.; Cavouras, D.; Kalivas, N.; Delis, H.; Panayiotakis, G.

    2007-09-01

    Phosphor materials are employed in intensifying screens of both digital and conventional X-ray imaging detectors. High packing density powder screens have been developed (e.g. screens in ceramic form) exhibiting high-resolution and light emission properties, and thus contributing to improved image transfer characteristics and higher radiation to light conversion efficiency. For the present study, a custom Monte Carlo simulation program was used in order to examine the performance of ceramic powder screens, under various radiographic conditions. The model was developed using Mie scattering theory for the description of light interactions, based on the physical characteristics (e.g. complex refractive index, light wavelength) of the phosphor material. Monte Carlo simulations were carried out assuming: (a) X-ray photon energy ranging from 18 up to 49 keV, (b) Gd 2O 2S:Tb phosphor material with packing density of 70% and grain size of 7 μm and (c) phosphor thickness ranging between 30 and 70 mg/cm 2. The variation of the Modulation Transfer Function (MTF) and the Luminescence Efficiency (LE) with respect to the X-ray energy and the phosphor thickness was evaluated. Both aforementioned imaging characteristics were shown to take high values at 49 keV X-ray energy and 70 mg/cm 2 phosphor thickness. It was found that high packing density screens may be appropriate for use in medical radiographic systems.

  3. 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.

  4. Determination of the weld thickness of turbine for aircraft engine by high-energy X-ray tomography

    OpenAIRE

    Zhong Yang; Chakhlov Sergei; Mamyrbayev Talgat

    2017-01-01

    It is necessary to test the weld thickness of turbine, as it is one of the most important parts for aircraft engine. The weld thickness of turbine for aircraft engine by high-energy X-ray tomography was determined. We used an X-ray tube and a betatron as X-ray sources. The wall thickness of two tubes and weld thickness of turbine were measured. It is shown that the high-energy X-ray tomography system is determined the wall thickness of the tube and the weld thickness of turbine with high accu...

  5. High Angular Resolution and Lightweight X-Ray Optics for Astronomical Missions

    Science.gov (United States)

    Zhang, W. W.; Biskach, M. P.; Blake, P. N.; Chan, K. W.; Evans, T. C.; Hong, M.; Jones, W. D.; Jones, W. D.; Kolos, L. D.; Mazzarella, J. M.; hide

    2011-01-01

    X-ray optics with both high angular resolution and lightweight is essential for further progress in x-ray astronomy. High angular resolution is important in avoiding source confusion and reducing background to enable the observation of the most distant objects of the early Universe. It is also important in enabling the use of gratings to achieve high spectral resolution to study, among other things, the myriad plasmas that exist in planetary, stellar, galactic environments, as well as interplanetary, inter-stellar, and inter-galactic media. Lightweight is important for further increase in effective photon collection area, because x-ray observations must take place on space platforms and the amount of mass that can be launched into space has always been very limited and is expected to continue to be very limited. This paper describes an x-ray optics development program and reports on its status that meets these two requirements. The objective of this program is to enable Explorer type missions in the near term and to enable flagship missions in the long term.

  6. On the use of CCD area detectors for high-resolution specular X-ray reflectivity.

    Science.gov (United States)

    Fenter, P; Catalano, J G; Park, C; Zhang, Z

    2006-07-01

    The use and application of charge coupled device (CCD) area detectors for high-resolution specular X-ray reflectivity is discussed. Direct comparison of high-resolution specular X-ray reflectivity data measured with CCD area detectors and traditional X-ray scintillator ('point') detectors demonstrates that the use of CCD detectors leads to a substantial (approximately 30-fold) reduction in data acquisition rates because of the elimination of the need to scan the sample to distinguish signal from background. The angular resolution with a CCD detector is also improved by a factor of approximately 3. The ability to probe the large dynamic range inherent to high-resolution X-ray reflectivity data in the specular reflection geometry was demonstrated with measurements of the orthoclase (001)- and alpha-Al2O3 (012)-water interfaces, with measured reflectivity signals varying by a factor of approximately 10(6) without the use of any beam attenuators. Statistical errors in the reflectivity signal are also derived and directly compared with the repeatability of the measurements.

  7. Total Reflection X-ray Fluorescence Analysis (TXRF) using the high flux SAXS camera

    CERN Document Server

    Wobrauschek, P; Pepponi, G; Bergmann, A; Glatter, O

    2002-01-01

    Combining the high photon flux from a rotating anode X-ray tube with an X-ray optical component to focus and monochromatize the X-ray beam is the most promising instrumentation for best detection limits in the modern XRF laboratory. This is realized by using the design of a high flux SAXS camera in combination with a 4 kW high brilliant rotating Cu anode X-ray tube with a graded elliptically bent multilayer and including a new designed module for excitation in total reflection geometry within the beam path. The system can be evacuated thus reducing absorption and scattering of air and removing the argon peak in the spectra. Another novelty is the use of a Peltier cooled drift detector with an energy resolution of 148 eV at 5.9 keV and 5 mm sup 2 area. For Co detection limits of about 300 fg determined by a single element standard have been achieved. Testing a real sample NIST 1643d led to detection limits in the range of 300 ng/l for the medium Z.

  8. Empirical electro-optical and x-ray performance evaluation of CMOS active pixels sensor for low dose, high resolution x-ray medical imaging.

    Science.gov (United States)

    Arvanitis, C D; Bohndiek, S E; Royle, G; Blue, A; Liang, H X; Clark, A; Prydderch, M; Turchetta, R; Speller, R

    2007-12-01

    Monolithic complementary metal oxide semiconductor (CMOS) active pixel sensors with high performance have gained attention in the last few years in many scientific and space applications. In order to evaluate the increasing capabilities of this technology, in particular where low dose high resolution x-ray medical imaging is required, critical electro-optical and physical x-ray performance evaluation was determined. The electro-optical performance includes read noise, full well capacity, interacting quantum efficiency, and pixels cross talk. The x-ray performance, including x-ray sensitivity, modulation transfer function, noise power spectrum, and detection quantum efficiency, has been evaluated in the mammographic energy range. The sensor is a 525 x 525 standard three transistor CMOS active pixel sensor array with more than 75% fill factor and 25 x 25 microm pixel pitch. Reading at 10 f/s, it is found that the sensor has 114 electrons total additive noise, 10(5) electrons full well capacity with shot noise limited operation, and 34% interacting quantum efficiency at 530 nm. Two different structured CsI:Tl phosphors with thickness 95 and 115 microm, respectively, have been optically coupled via a fiber optic plate to the array resulting in two different system configurations. The sensitivity of the two different system configurations was 43 and 47 electrons per x-ray incident on the sensor. The MTF at 10% of the two different system configurations was 9.5 and 9 cycles/mm with detective quantum efficiency of 0.45 and 0.48, respectively, close to zero frequency at approximately 0.44 microC/kg (1.72 mR) detector entrance exposure. The detector was quantum limited at low spatial frequencies and its performance was comparable with high resolution a: Si and charge coupled device based x-ray imagers. The detector also demonstrates almost an order of magnitude lower noise than active matrix flat panel imagers. The results suggest that CMOS active pixel sensors when coupled

  9. Fabrication of large area X-ray diffraction grating for X-ray phase imaging

    Science.gov (United States)

    Noda, Daiji; Tokuoka, Atsushi; Katori, Megumi; Minamiyama, Yasuto; Yamashita, Kenji; Nishida, Satoshi; Hattori, Tadashi

    2012-07-01

    X-ray lithography, which uses highly directional synchrotron radiation, is one of the technologies that can be used for fabricating micrometer-sized structures. In X-ray lithography, the accuracy of the fabricated structure depends largely on the accuracy of the X-ray mask. Since X-ray radiation is highly directional, a micro-fabrication technology that produces un-tapered and high aspect ratio highly absorbent structures on a low absorbent membrane is required. Conventionally, a resin material is used as the support membrane for large area X-ray masks. However, resin membranes have the disadvantage that they can sag after several cycles of X-ray exposure due to the heat generated by the X-rays. Therefore, we proposed and used thin carbon wafers for the membrane material because carbon has an extremely small thermal expansion coefficient. We fabricated new carbon membrane X-ray masks, and these results of X-ray lithography demonstrate the superior performance.

  10. High-resolution X-ray diffraction imaging of non-Bragg diffracting materials using phase retrieval X-ray diffractometry (PRXRD) technique

    Energy Technology Data Exchange (ETDEWEB)

    Nikulin, A.Y.; Darahanau, A.V.; Horney, R.; Ishikawa, T

    2004-06-15

    An X-ray diffraction technique has recently been developed and successfully applied to comprehensively, including both phase and amplitude contrast, map the complex refractive index of non-crystalline materials with submicron spatial resolution. The methodology is based on the measurement of a high angular resolution X-ray Fraunhofer diffraction pattern with further application of the phase-retrieval formalism using a logarithmic dispersion relation. The technique is reviewed from the perspective of its ability to deliver ultra-high, order of several nanometres, spatial resolution and to uniquely determine both the real and imaginary components of the complex refractive index of the material under analysis. Potential niche of practical applications is discussed in terms of the spatial resolution and field of view achievable by the method.

  11. 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.

  12. Precision mechanical structure of an ultra-high-resolution spectrometer for inelastic X-ray scattering instrument

    Science.gov (United States)

    Shu, Deming; Shvydko, Yuri; Stoupin, Stanislav A.; Khachatryan, Ruben; Goetze, Kurt A.; Roberts, Timothy

    2015-04-14

    A method and an ultrahigh-resolution spectrometer including a precision mechanical structure for positioning inelastic X-ray scattering optics are provided. The spectrometer includes an X-ray monochromator and an X-ray analyzer, each including X-ray optics of a collimating (C) crystal, a pair of dispersing (D) element crystals, anomalous transmission filter (F) and a wavelength (W) selector crystal. A respective precision mechanical structure is provided with the X-ray monochromator and the X-ray analyzer. The precision mechanical structure includes a base plate, such as an aluminum base plate; positioning stages for D-crystal alignment; positioning stages with an incline sensor for C/F/W-crystal alignment, and the positioning stages including flexure-based high-stiffness structure.

  13. X-Ray Polarimetry

    OpenAIRE

    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 ...

  14. Accuracy of Mass and Radius Determination for Neutron Stars in X-ray Bursters from Simulated LOFT Spectra

    Science.gov (United States)

    Majczyna, A.; Madej, J.; Różańska, A.; Należyty, M.

    2017-06-01

    We present a simulation of an X-ray spectrum of a hot neutron star, as would be seen by the LAD detector on board of LOFT satellite. We also compute a grid of theoretical spectra corresponding to a range of effective temperatures Teff and surface gravities log g with values corresponding to compact stars in Type I X-ray bursters. A neutron star with the mass M=1.64 M⊙ and the radius R=11.95 km (which yields the surface gravity log g=14.30 [cgs] and the surface redshift z=0.30) is used in simulation. Accuracy of mass and radius determination by fitting theoretical spectra to the observed one is found to be M=1.64+0.16-0.02 M⊙ and R=11.95+1.57-0.40 km (2σ). The confidence contours for these two variables are narrow but elongated, and therefore the resulting constraints on the EOS cannot be strong. Note, that in this paper we aim to discuss error contours of NS mass and radius, whereas discussion of EOS is beyond the scope of this work.

  15. High-Resolution X-Ray Spectra of the Symbiotic Star SS73 17

    Science.gov (United States)

    Eze, R. N. C.; Luna, G. J. M.; Smith, R. K.

    2010-01-01

    SS73 17 was an innocuous Mira-type symbiotic star until the International Gamma-Ray Astrophysics Laboratory and Swift discovered its bright hard X-ray emission, adding it to the small class of "hard X-ray emitting symbiotics." Suzaku observations in 2006 then showed it emits three bright iron lines as well, with little to no emission in the 0.3-2.0 keV bandpass. We present here follow-up observations with the Chandra High Energy Transmission Grating and Suzaku that confirm the earlier detection of strong emission lines of Fe K(alpha) fluorescence, Fe XXV and Fe XXVI but also show significantly more soft X-ray emission. The high-resolution spectrum also shows emission lines of other highly ionized ions as Si xiv and possibly S XVI. In addition, a re-analysis of the 2006 Suzaku data using the latest calibration shows that the hard (15-50 keV) X-ray emission is brighter than previously thought and remains constant in both the 2006 and 2008 data. The G ratio calculated from the Fe xxv lines shows that these lines are thermal, not photoionized, in origin.With the exception of the hard X-ray emission, the spectra from both epochs can be fit using thermal radiation assuming a differential emission measure based on a cooling-flow model combined with a full and partial absorber. We show that acceptable fits can be obtained for all the data in the 1-10 keV band varying only the partial absorber. Based on the temperature and accretion rate, the thermal emission appears to be arising from the boundary layer between the accreting white dwarf and the accretion disk.

  16. High-energy neutrino fluxes from AGN populations inferred from X-ray surveys

    Science.gov (United States)

    Jacobsen, Idunn B.; Wu, Kinwah; On, Alvina Y. L.; Saxton, Curtis J.

    2015-08-01

    High-energy neutrinos and photons are complementary messengers, probing violent astrophysical processes and structural evolution of the Universe. X-ray and neutrino observations jointly constrain conditions in active galactic nuclei (AGN) jets: their baryonic and leptonic contents, and particle production efficiency. Testing two standard neutrino production models for local source Cen A (Koers & Tinyakov and Becker & Biermann), we calculate the high-energy neutrino spectra of single AGN sources and derive the flux of high-energy neutrinos expected for the current epoch. Assuming that accretion determines both X-rays and particle creation, our parametric scaling relations predict neutrino yield in various AGN classes. We derive redshift-dependent number densities of each class, from Chandra and Swift/BAT X-ray luminosity functions (Silverman et al. and Ajello et al.). We integrate the neutrino spectrum expected from the cumulative history of AGN (correcting for cosmological and source effects, e.g. jet orientation and beaming). Both emission scenarios yield neutrino fluxes well above limits set by IceCube (by ˜4-106 × at 1 PeV, depending on the assumed jet models for neutrino production). This implies that: (i) Cen A might not be a typical neutrino source as commonly assumed; (ii) both neutrino production models overestimate the efficiency; (iii) neutrino luminosity scales with accretion power differently among AGN classes and hence does not follow X-ray luminosity universally; (iv) some AGN are neutrino-quiet (e.g. below a power threshold for neutrino production); (v) neutrino and X-ray emission have different duty cycles (e.g. jets alternate between baryonic and leptonic flows); or (vi) some combination of the above.

  17. High-energy Neutrino Flares from X-Ray Bright and Dark Tidal Disruption Events

    Energy Technology Data Exchange (ETDEWEB)

    Senno, Nicholas; Murase, Kohta; Mészáros, Peter [Department of Physics, The Pennsylvania State University, University Park, PA 16802 (United States)

    2017-03-20

    X-ray and γ-ray observations by the Swift satellite revealed that a fraction of tidal disruption events (TDEs) have relativistic jets. Jetted TDEs have been considered to be potential sources of very-high-energy cosmic-rays and neutrinos. In this work, using semi-analytical methods, we calculate neutrino spectra of X-ray bright TDEs with powerful jets and dark TDEs with possible choked jets, respectively. We estimate their neutrino fluxes and find that non-detection would give us an upper limit on the baryon loading of the jet luminosity contained in cosmic-rays ξ {sub cr} ≲ 20–50 for Sw J1644+57. We show that X-ray bright TDEs make a sub-dominant (≲5%–10%) contribution to IceCube’s diffuse neutrino flux, and study possible contributions of X-ray dark TDEs given that particles are accelerated in choked jets or disk winds. We discuss future prospects for multi-messenger searches of the brightest TDEs.

  18. Characterization of high-resolution diffractive X-ray optics by ptychographic coherent diffractive imaging.

    Science.gov (United States)

    Vila-Comamala, Joan; Diaz, Ana; Guizar-Sicairos, Manuel; Mantion, Alexandre; Kewish, Cameron M; Menzel, Andreas; Bunk, Oliver; David, Christian

    2011-10-24

    We have employed ptychographic coherent diffractive imaging to completely characterize the focal spot wavefield and wavefront aberrations of a high-resolution diffractive X-ray lens. The ptychographic data from a strongly scattering object was acquired using the radiation cone emanating from a coherently illuminated Fresnel zone plate at a photon energy of 6.2 keV. Reconstructed images of the object were retrieved with a spatial resolution of 8 nm by combining the difference-map phase retrieval algorithm with a non-linear optimization refinement. By numerically propagating the reconstructed illumination function, we have obtained the X-ray wavefield profile of the 23 nm round focus of the Fresnel zone plate (outermost zone width, Δr = 20 nm) as well as the X-ray wavefront at the exit pupil of the lens. The measurements of the wavefront aberrations were repeatable to within a root mean square error of 0.006 waves, and we demonstrate that they can be related to manufacturing aspects of the diffractive optical element and to errors on the incident X-ray wavefront introduced by the upstream beamline optics. © 2011 Optical Society of America

  19. High resolution x-ray lensless imaging by differential holographic encoding

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, D.; Guizar-Sicairos, M.; Wu, B.; Scherz, A.; Acremann, Y.; Tylisczcak, T.; Fischer, P.; Friedenberger, N.; Ollefs, K.; Farle, M.; Fienup, J. R.; Stohr, J.

    2009-11-02

    X-ray free electron lasers (X-FEL{sub s}) will soon offer femtosecond pulses of laterally coherent x-rays with sufficient intensity to record single-shot coherent scattering patterns for nanoscale imaging. Pulse trains created by splitand-delay techniques even open the door for cinematography on unprecedented nanometer length and femtosecond time scales. A key to real space ultrafast motion pictures is fast and reliable inversion of the recorded reciprocal space scattering patterns. Here we for the first time demonstrate in the x-ray regime the power of a novel technique for lensless high resolution imaging, previously suggested by Guizar-Sicairos and Fienup termed holography with extended reference by autocorrelation linear differential operation, HERALD0. We have achieved superior resolution over conventional x-ray Fourier transform holography (FTH) without sacrifices in SNR or significant increase in algorithmic complexity. By combining images obtained from individual sharp features on an extended reference, we further show that the resolution can be even extended beyond the reference fabrication limits. Direct comparison to iterative phase retrieval image reconstruction and images recorded with stateof- the-art zone plate microscopes is presented. Our results demonstrate the power of HERALDO as a favorable candidate for robust inversion of single-shot coherent scattering patterns.

  20. The X-ray high resolution Chandra spectra of Nova SMC 2016

    Science.gov (United States)

    Orio, Marina; Aydi, Elias; Behar, Ehud; Buckley, David; Dobrotka, Andrej; Ness, Jan-Uwe; Page, Kim L.; Rauch, Thomas; Zemko, Polina

    2017-08-01

    Nova SMC 2016 was discovered in the direction of the SMC by the MASTER Global Robotic Net on 2016 October 14. At peak optical magnitude B~9.55, if it is located in the SMC it is one of the intrinsically most luminous novae ever recorded. The X-ray to optical luminosity of the nova is around the average value, so it was also very X-ray luminous for a nova in the SMC. It was classified as a fast nova. It was monitored with Swift until the present day (2017 May), with close cadence whenever it was feasible, and we were able to observe it on the rise to maximum X-ray luminosity on 2016 November 17-18 and at maximum on 2017 January 4 with the Chandra Low Energy Transmission Grating (another high resolution X-ray spectrum was obtained with XMM-Newton on 2016 December 22). We report on the luminous supersoft spectrum of the central source observed with Chandra, a luminous stellar continuum with effective temperature of about 650,000 K in December and 750,000 K in January, with deep absorption features of carbon, nitrogen and sulphur, blue-shifted by about 1700 km/s in November and by 2100 km/s in January. We describe the results of our initial spectral and timing analysis.

  1. High-Resolution X-Ray Lensless Imaging by Differential Holographic Encoding

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Diling [Stanford Univ., CA (United States). Dept. of Applied Physics; SLAC National Accelerator Lab., Menlo Park, CA (United States). Stanford Inst. for Material and Energy Science; Guizar-Sicairos, Manuel [Univ. of Rochester, NY (United States). Inst. of Optics; Wu, Benny [Stanford Univ., CA (United States). Dept. of Applied Physics; SLAC National Accelerator Lab., Menlo Park, CA (United States). Stanford Inst. for Material and Energy Science; Scherz, Andreas [SLAC National Accelerator Lab., Menlo Park, CA (United States). Stanford Inst. for Material and Energy Science; Acremann, Yves [SLAC National Accelerator Lab., Menlo Park, CA (United States). Photon Ultrafast Laser Science and Engineering Inst. (PULSE); Tyliszczak, Tolek [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Advanced Light Source (ALS); Fischer, Peter [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Center for X-ray Optics; Friedenberger, Nina [Universitat Duisburg-Essen (Germany). Dept. of Physics and Center for Nanointegration Duisburg-Essen (CeNIDE); Ollefs, Katharina [Universitat Duisburg-Essen (Germany). Dept. of Physics and Center for Nanointegration Duisburg-Essen (CeNIDE); Farle, Michael [Universitat Duisburg-Essen (Germany). Dept. of Physics and Center for Nanointegration Duisburg-Essen (CeNIDE); Fienup, James R. [Univ. of Rochester, NY (United States). Inst. of Optics; Stöhr, Joachim [SLAC National Accelerator Lab., Menlo Park, CA (United States). Linac Coherent Light Source (LCLS)

    2010-07-01

    X-ray free electron lasers (X-FELs) will soon offer femtosecond pulses of laterally coherent x-rays with sufficient intensity to record single-shot coherent scattering patterns for nanoscale imaging. Pulse trains created by split and- delay techniques even open the door for cinematography on unprecedented nanometer length and femtosecond time scales. A key to real space ultrafast motion pictures is fast and reliable inversion of the recorded reciprocal space scattering patterns. Here we for the first time demonstrate in the x-ray regime the power of a novel technique for lensless high resolution imaging, previously suggested by Guizar-Sicairos and Fienup termed holography with extended reference by autocorrelation linear differential operation, HERALD0. We have achieved superior resolution over conventional x-ray Fourier transform holography (FTH) without sacrifices in SNR or significant increase in algorithmic complexity. By combining images obtained from individual sharp features on an extended reference, we further show that the resolution can be even extended beyond the reference fabrication limits. Direct comparison to iterative phase retrieval image reconstruction and images recorded with state of-the-art zone plate microscopes is presented. Our results demonstrate the power of HERALDO as a favorable candidate for robust inversion of single-shot coherent scattering patterns.

  2. The Nuclear Spectroscopic Telescope Array (NuSTAR) High-Energy X-ray Mission

    Science.gov (United States)

    Harrison, Fiona A.; Craig, Willliam W.; Christensen, Finn E.; Hailey, Charles J.; Zhang, William W.; Boggs, Steven E.; Stern, Daniel; Cook, W. Rick; Forster, Karl; Giommi, Paolo; hide

    2013-01-01

    High-energy X-ray telescope in orbit. NuSTAR operates in the band from 3 to 79 keV, extending the sensitivity of focusing far beyond the 10 keV high-energy cutoff achieved by all previous X-ray satellites. The inherently low background associated with concentrating the X-ray light enables NuSTAR to probe the hard X-ray sky with a more than 100-fold improvement in sensitivity over the collimated or coded mask instruments that have operated in this bandpass. Using its unprecedented combination of sensitivity and spatial and spectral resolution, NuSTAR will pursue five primary scientific objectives: (1) probe obscured active galactic nucleus (AGN) activity out to thepeak epoch of galaxy assembly in the universe (at z 2) by surveying selected regions of the sky; (2) study the population of hard X-ray-emitting compact objects in the Galaxy by mapping the central regions of the Milky Way; (3) study the non-thermal radiation in young supernova remnants, both the hard X-ray continuum and the emission from the radioactive element 44Ti; (4) observe blazars contemporaneously with ground-based radio, optical, and TeV telescopes, as well as with Fermi and Swift, to constrain the structure of AGN jets; and (5) observe line and continuum emission from core-collapse supernovae in the Local Group, and from nearby Type Ia events, to constrain explosion models. During its baseline two-year mission, NuSTAR will also undertake a broad program of targeted observations. The observatory consists of two co-aligned grazing-incidence X-ray telescopes pointed at celestial targets by a three-axis stabilized spacecraft. Deployed into a 600 km, near-circular, 6 inclination orbit, the observatory has now completed commissioning, and is performing consistent with pre-launch expectations. NuSTAR is now executing its primary science mission, and with an expected orbit lifetime of 10 yr, we anticipate proposing a guest investigator program, to begin in late 2014.

  3. High-speed X-ray imaging pixel array detector for synchrotron bunch isolation

    Energy Technology Data Exchange (ETDEWEB)

    Philipp, Hugh T., E-mail: htp2@cornell.edu; Tate, Mark W.; Purohit, Prafull; Shanks, Katherine S.; Weiss, Joel T. [Cornell University, Ithaca, NY 14853 (United States); Gruner, Sol M. [Cornell University, Ithaca, NY 14853 (United States); Cornell University, Ithaca, NY 14853 (United States)

    2016-01-28

    A high-speed pixel array detector for time-resolved X-ray imaging at synchrotrons has been developed. The ability to isolate single synchrotron bunches makes it ideal for time-resolved dynamical studies. A wide-dynamic-range imaging X-ray detector designed for recording successive frames at rates up to 10 MHz is described. X-ray imaging with frame rates of up to 6.5 MHz have been experimentally verified. The pixel design allows for up to 8–12 frames to be stored internally at high speed before readout, which occurs at a 1 kHz frame rate. An additional mode of operation allows the integration capacitors to be re-addressed repeatedly before readout which can enhance the signal-to-noise ratio of cyclical processes. This detector, along with modern storage ring sources which provide short (10–100 ps) and intense X-ray pulses at megahertz rates, opens new avenues for the study of rapid structural changes in materials. The detector consists of hybridized modules, each of which is comprised of a 500 µm-thick silicon X-ray sensor solder bump-bonded, pixel by pixel, to an application-specific integrated circuit. The format of each module is 128 × 128 pixels with a pixel pitch of 150 µm. In the prototype detector described here, the three-side buttable modules are tiled in a 3 × 2 array with a full format of 256 × 384 pixels. The characteristics, operation, testing and application of the detector are detailed.

  4. Implications of heavy-ion-induced satellite x-ray emission. III. Chemical effects in high resolution sulfur K/sub. cap alpha. / x-ray spectra

    Energy Technology Data Exchange (ETDEWEB)

    Vane, C.R.; Hulett, L.D. Jr.; Kahane, S.; McDaniel, F.D.; Milner, W.T.; Raman, S.; Rosseel, T.M.; Slaughter, G.G.; Varghese, S.L.; Young, J.P.

    1983-01-01

    High resolution (approx. 7 eV at 2.3 keV) sulfur K/sub ..cap alpha../ x-ray spectra have been obtained for a series of sulfur compound targets under heavy ion impact at the Holified Heavy Ion Facility. The spectra observed are dominated by a series of satellite peaks arising from varying degrees of L-shell ionization at the time of x-ray emission. Each spectral profile has been parameterized by a single variable p/sub L/, the apparent average L-shell ionization probability. Correlations are evident between p/sub L/ and the corresponding sulfur atom chemical environment. Much stronger correlations are however found for variations of some individual peak intensities with specific chemical parameters. Comparison of results for Ar/sup q+/ and Kr/sup q+/ projectiles shows that while L-shell ionization probability has increased, chemical sensitivity has apparently saturated.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-08-15

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

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

    Science.gov (United States)

    Higley, Daniel J.; Hirsch, Konstantin; Dakovski, Georgi L.; Jal, Emmanuelle; Yuan, Edwin; Liu, Tianmin; Lutman, Alberto A.; MacArthur, James P.; Arenholz, Elke; Chen, Zhao; Coslovich, Giacomo; Denes, Peter; Granitzka, Patrick W.; Hart, Philip; Hoffmann, Matthias C.; Joseph, John; Le Guyader, Loïc; Mitra, Ankush; Moeller, Stefan; Ohldag, Hendrik; Seaberg, Matthew; Shafer, Padraic; Stöhr, Joachim; Tsukamoto, Arata; Nuhn, Heinz-Dieter; Reid, Alex H.; Dürr, Hermann A.; Schlotter, William F.

    2016-03-01

    X-ray magnetic circular dichroism spectroscopy using an X-ray free electron laser is demonstrated with spectra over the Fe L3,2-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.

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

    Science.gov (United States)

    Higley, Daniel J; Hirsch, Konstantin; Dakovski, Georgi L; Jal, Emmanuelle; Yuan, Edwin; Liu, Tianmin; Lutman, Alberto A; MacArthur, James P; Arenholz, Elke; Chen, Zhao; Coslovich, Giacomo; Denes, Peter; Granitzka, Patrick W; Hart, Philip; Hoffmann, Matthias C; Joseph, John; Le Guyader, Loïc; Mitra, Ankush; Moeller, Stefan; Ohldag, Hendrik; Seaberg, Matthew; Shafer, Padraic; Stöhr, Joachim; Tsukamoto, Arata; Nuhn, Heinz-Dieter; Reid, Alex H; Dürr, Hermann A; Schlotter, William F

    2016-03-01

    X-ray magnetic circular dichroism spectroscopy using an X-ray free electron laser is demonstrated with spectra over the Fe L(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.

  8. 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.

  9. Calculations and surface quality measurements of high-asymmetry angle x-ray crystal monochromators for advanced x-ray imaging and metrological applications

    Science.gov (United States)

    Zápražný, Zdenko; Korytár, Dušan; Jergel, Matej; Šiffalovič, Peter; Dobročka, Edmund; Vagovič, Patrik; Ferrari, Claudio; Mikulík, Petr; Demydenko, Maksym; Mikloška, Marek

    2015-03-01

    We present the numerical optimization and the technological development progress of x-ray optics based on asymmetric germanium crystals. We show the results of several basic calculations of diffraction properties of germanium x-ray crystal monochromators and of an analyzer-based imaging method for various asymmetry factors using an x-ray energy range from 8 to 20 keV. The important parameter of highly asymmetric monochromators as image magnifiers or compressors is the crystal surface quality. We have applied several crystal surface finishing methods, including advanced nanomachining using single-point diamond turning (SPDT), conventional mechanical lapping, chemical polishing, and chemomechanical polishing, and we have evaluated these methods by means of atomic force microscopy, diffractometry, reciprocal space mapping, and others. Our goal is to exclude the chemical etching methods as the final processing technique because it causes surface undulations. The aim is to implement very precise deterministic methods with a control of surface roughness down to 0.1 nm. The smallest roughness (˜0.3 nm), best planarity, and absence of the subsurface damage were observed for the sample which was machined using an SPDT with a feed rate of 1 mm/min and was consequently polished using a fine polishing 15-min process with a solution containing SiO2 nanoparticles (20 nm).

  10. Testing the Performance and Accuracy of the RELXILL Model for the Relativistic X-Ray Reflection from Accretion Disks

    Science.gov (United States)

    Choudhury, Kishalay; García, Javier A.; Steiner, James F.; Bambi, Cosimo

    2017-12-01

    The reflection spectroscopic model RELXILL is commonly implemented in studying relativistic X-ray reflection from accretion disks around black holes. We present a systematic study of the model’s capability to constrain the dimensionless spin and ionization parameters from ∼6000 Nuclear Spectroscopic Telescope Array (NuSTAR) simulations of a bright X-ray source employing the lamp-post geometry. We employ high-count spectra to show the limitations in the model without being confused with limitations in signal-to-noise. We find that both parameters are well-recovered at 90% confidence with improving constraints at higher reflection fraction, high spin, and low source height. We test spectra across a broad range—first at 106–107 and then ∼105 total source counts across the effective 3–79 keV band of NuSTAR, and discover a strong dependence of the results on how fits are performed around the starting parameters, owing to the complexity of the model itself. A blind fit chosen over an approach that carries some estimates of the actual parameter values can lead to significantly worse recovery of model parameters. We further stress the importance to span the space of nonlinear-behaving parameters like {log} ξ carefully and thoroughly for the model to avoid misleading results. In light of selecting fitting procedures, we recall the necessity to pay attention to the choice of data binning and fit statistics used to test the goodness of fit by demonstrating the effect on the photon index Γ. We re-emphasize and implore the need to account for the detector resolution while binning X-ray data and using Poisson fit statistics instead while analyzing Poissonian data.

  11. In-situ high-P, T X-ray microtomographic imaging during large deformation

    DEFF Research Database (Denmark)

    Wang, Y; Lesher, Charles

    2011-01-01

    We have examined the microstructural evolution of a two-phase composite (olivine + Fe-Ni-S) during large shear deformation, using a newly developed high-pressure X-ray tomography microscope. Two samples were examined: a load-bearing framework–type texture, where the alloy phase (Fe-Ni-S) was pres......We have examined the microstructural evolution of a two-phase composite (olivine + Fe-Ni-S) during large shear deformation, using a newly developed high-pressure X-ray tomography microscope. Two samples were examined: a load-bearing framework–type texture, where the alloy phase (Fe...... deformation at temperatures up to 800 K. Shear strains were introduced by twisting the samples at high pressure and high temperature. At each imposed shear strain, samples were cooled to ambient temperature and tomographic images collected. The three-dimensional tomographic images were analyzed for textural...

  12. Production of High Harmonic X-Ray Radiation from Non-linear Thomson at LLNL PLEIADES

    CERN Document Server

    Lim, Jae; Betts, Shawn; Crane, John; Doyuran, Adnan; Frigola, Pedro; Gibson, David J; Hartemann, Fred V; Rosenzweig, James E; Travish, Gil; Tremaine, Aaron M

    2005-01-01

    We describe an experiment for production of high harmonic x-ray radiation from Thomson backscattering of an ultra-short high power density laser by a relativistic electron beam at the PLEIADES facility at LLNL. In this scenario, electrons execute a “figure-8” motion under the influence of the high-intensity laser field, where the constant characterizing the field strength is expected to exceed unity: $aL=e*EL/m*c*ωL ≥ 1$. With large $aL$ this motion produces high harmonic x-ray radiation and significant broadening of the spectral peaks. This paper is intended to give a layout of the PLEIADES experiment, along with progress towards experimental goals.

  13. High-pressure powder x-ray diffraction experiments on Zn at low temperature

    CERN Document Server

    Takemura, K; Fujihisa, H; Kikegawa, T

    2002-01-01

    High-pressure powder x-ray diffraction experiments have been performed on Zn with a He-pressure medium at low temperature. When the sample was compressed in the He medium at low temperature, large nonhydrostaticity developed, yielding erroneous lattice parameters. On the other hand, when the pressure was changed at high temperatures, good hydrostaticity was maintained. No anomaly in the volume dependence of the c/a axial ratio has been found.

  14. Dynamic crystal rotation resolved by high-speed synchrotron X-ray Laue diffraction

    OpenAIRE

    Huang, J.W.; E, J. C.; Huang, J. Y.; Sun, T.; Fezzaa, K.; Luo, S.N.

    2016-01-01

    Dynamic compression experiments are performed on single-crystal Si under split Hopkinson pressure bar loading, together with simultaneous high-speed (250?350?ns resolution) synchrotron X-ray Laue diffraction and phase-contrast imaging. A methodology is presented which determines crystal rotation parameters, i.e. instantaneous rotation axes and angles, from two unindexed Laue diffraction spots. Two-dimensional translation is obtained from dynamic imaging by a single camera. High-speed motion o...

  15. A Study on Stereoscopic X-ray Imaging Data Set on the Accuracy of Real-Time Tumor Tracking in External Beam Radiotherapy.

    Science.gov (United States)

    Esmaili Torshabi, Ahmad; Ghorbanzadeh, Leila

    2017-04-01

    At external beam radiotherapy, stereoscopic X-ray imaging system is responsible as tumor motion information provider. This system takes X-ray images intermittently from tumor position (1) at pretreatment step to provide training data set for model construction and (2) during treatment to control the accuracy of correlation model performance. In this work, we investigated the effect of imaging data points provided by this system on treatment quality. Because some information is still lacking about (1) the number of imaging data points, (2) shooting time for capturing each data point, and also (3) additional imaging dose delivered by this system. These 3 issues were comprehensively assessed at (1) pretreatment step while training data set is gathered for prediction model construction and (2) during treatment while model is tested and reconstructed using new arrival data points. A group of real patients treated with CyberKnife Synchrony module was chosen in this work, and an adaptive neuro-fuzzy inference system was considered as consistent correlation model. Results show that a proper model can be constructed while the number of imaging data points is highly enough to represent a good pattern of breathing cycles. Moreover, a trade-off between the number of imaging data points and additional imaging dose is considered in this study. Since breathing phenomena are highly variable at different patients, the time for taking some of imaging data points is very important, while their absence at that critical time may yield wrong tumor tracking. In contrast, the sensitivity of another category of imaging data points is not high, while breathing is normal and in the control range. Therefore, an adaptive supervision on the implementation of stereoscopic X-ray imaging is proposed to intelligently accomplish shooting process, based on breathing motion variations.

  16. Automated high pressure cell for pressure jump x-ray diffraction.

    Science.gov (United States)

    Brooks, Nicholas J; Gauthe, Beatrice L L E; Terrill, Nick J; Rogers, Sarah E; Templer, Richard H; Ces, Oscar; Seddon, John M

    2010-06-01

    A high pressure cell for small and wide-angle x-ray diffraction measurements of soft condensed matter samples has been developed, incorporating a fully automated pressure generating network. The system allows both static and pressure jump measurements in the range of 0.1-500 MPa. Pressure jumps can be performed as quickly as 5 ms, both with increasing and decreasing pressures. Pressure is generated by a motorized high pressure pump, and the system is controlled remotely via a graphical user interface to allow operation by a broad user base, many of whom may have little previous experience of high pressure technology. Samples are loaded through a dedicated port allowing the x-ray windows to remain in place throughout an experiment; this facilitates accurate subtraction of background scattering. The system has been designed specifically for use at beamline I22 at the Diamond Light Source, United Kingdom, and has been fully integrated with the I22 beamline control systems.

  17. Depth Probing Soft X-ray Microprobe (DPSXRM) for High Resolution Probing of Earth's Microstructural Samples

    Science.gov (United States)

    Dikedi, P. N.

    2015-12-01

    The Cambrian explosion; occurrence of landslides in very dry weather conditions; rockslides; dead, shriveled-up and crumbled leaves possessing fossil records with the semblance of well preserved, flat leaves; abundance of trilobite tracks in lower and higher rock layers; and sailing stones are enigmas demanding demystifications. These enigmas could be elucidated when data on soil structure, texture and strength are provided by some device with submicrometre accuracy; for these and other reasons, the design of a Depth Probing Soft X-ray Microprobe (DPSXRM), is being proposed; it is expected to deliver soft X-rays, at spatial resolution, ϛ≥600nm and to probe at the depth of 0.5m in 17s. The microprobe is portable compared to a synchrotron radiation facility (Diamond Light Source has land size of 43,300m2); spatial resolution,ϛ , of the DPSXRM surpasses those of the X-ray Fluorescence microanalysis (10µm), electron microprobe (1-3µm) and ion microprobe (5->30µm); the DPSXRM has allowance for multiple targets. Vanadium and Manganese membranes are proposed owing to respective 4.952KeV VKα1 and 5.899KeV MnKα1 X-rays emitted, which best suits micro-probing of Earth's microstructural samples. Compound systems like the Kirk-Patrick and Baez and Wolter optics, aspheric mirrors like elliptical and parabolic optics, small apertures and Abbe sine condition are employed to reduce or remove astigmatism, obliquity, comatic and spherical aberrations—leading to good image quality. Results show that 5.899KeV MnKα1 and 4.952KeV VKα1 soft X-rays will travel a distance of 2.75mm to form circular patches of radii 2.2mm and 2.95mm respectively. Zone plate with nth zone radius of 1.5mm must be positioned 1.5mm and 2mm from the electron gun if circular patches must be formed from 4.952KeV VKα1 and 5.899KeV MnKα1 soft X-rays respectively. The focal lengths of 0.25μm≤ƒ≤1.50μm and 0.04μm≤ƒ≤0.2μm covered by 4.952KeV VKα1 and 5.899KeV Mn Kα1 soft X-Rays, will

  18. Using High-Mass X-ray Binaries to Probe Massive Binary Evolution

    Science.gov (United States)

    Garofali, Kristen; Williams, Ben

    2018-01-01

    High-mass X-ray binaries (HMXBs) provide an exciting window into the underlying processes of both binary as well as massive star evolution. Because HMXBs are systems containing a compact object accreting from a high-mass star at close orbital separations they are also likely progenitors of gamma-ray bursts and gravitational wave sources. I will present work on the classification and age measurements of HMXBs in M33 using a combination of deep Chandra X-ray imaging, and archival Hubble Space Telescope data. I am able to constrain the ages of the HMXB candidates by fitting the color-magnitude diagrams of the surrounding stars, which yield the star formation histories of the surrounding region. Unlike the age distributions measured for HMXB populations in the Magellenic Clouds, the age distribution for the HMXB population in M33 contains a number of extremely young (properties on the observed HMXB population.

  19. Development of a dual MCP framing camera for high energy x-rays.

    Science.gov (United States)

    Izumi, N; Hall, G N; Carpenter, A C; Allen, F V; Cruz, J G; Felker, B; Hargrove, D; Holder, J; Kilkenny, J D; Lumbard, A; Montesanti, R; Palmer, N E; Piston, K; Stone, G; Thao, M; Vern, R; Zacharias, R; Landen, O L; Tommasini, R; Bradley, D K; Bell, P M

    2014-11-01

    Recently developed diagnostic techniques at LLNL require recording backlit images of extremely dense imploded plasmas using hard x-rays, and demand the detector to be sensitive to photons with energies higher than 50 keV [R. Tommasini et al., Phys. Phys. Plasmas 18, 056309 (2011); G. N. Hall et al., "AXIS: An instrument for imaging Compton radiographs using ARC on the NIF," Rev. Sci. Instrum. (these proceedings)]. To increase the sensitivity in the high energy region, we propose to use a combination of two MCPs. The first MCP is operated in a low gain regime and works as a thick photocathode, and the second MCP works as a high gain electron multiplier. We tested the concept of this dual MCP configuration and succeeded in obtaining a detective quantum efficiency of 4.5% for 59 keV x-rays, 3 times larger than with a single plate of the thickness typically used in NIF framing cameras.

  20. High energy X-ray photon counting imaging using linear accelerator and silicon strip detectors

    Energy Technology Data Exchange (ETDEWEB)

    Tian, Y., E-mail: cycjty@sophie.q.t.u-tokyo.ac.jp [Department of Bioengineering, the University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan); Shimazoe, K.; Yan, X. [Department of Nuclear Engineering and Management, the University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan); Ueda, O.; Ishikura, T. [Fuji Electric Co., Ltd., Fuji, Hino, Tokyo 191-8502 (Japan); Fujiwara, T. [National Institute of Advanced Industrial Science and Technology, 1-1-1 Umezono, Tsukuba, Ibaraki 305-8568 (Japan); Uesaka, M.; Ohno, M. [Nuclear Professional School, the University of Tokyo, 2-22 Shirakata-shirane, Tokai, Ibaraki 319-1188 (Japan); Tomita, H. [Department of Quantum Engineering, Nagoya University, Furo, Chikusa, Nagoya 464-8603 (Japan); Yoshihara, Y. [Department of Nuclear Engineering and Management, the University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan); Takahashi, H. [Department of Bioengineering, the University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan); Department of Nuclear Engineering and Management, the University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan)

    2016-09-11

    A photon counting imaging detector system for high energy X-rays is developed for on-site non-destructive testing of thick objects. One-dimensional silicon strip (1 mm pitch) detectors are stacked to form a two-dimensional edge-on module. Each detector is connected to a 48-channel application specific integrated circuit (ASIC). The threshold-triggered events are recorded by a field programmable gate array based counter in each channel. The detector prototype is tested using 950 kV linear accelerator X-rays. The fast CR shaper (300 ns pulse width) of the ASIC makes it possible to deal with the high instant count rate during the 2 μs beam pulse. The preliminary imaging results of several metal and concrete samples are demonstrated.

  1. Kinematic Alignment and Bonding of Silicon Mirrors for High-Resolution Astronomical X-Ray Optics

    Science.gov (United States)

    Chan, Kai-Wing; Mazzarella, James R.; Saha, Timo T.; Zhang, William W.; Mcclelland, Ryan S.; Biskack, Michael P.; Riveros, Raul E.; Allgood, Kim D.; Kearney, John D.; Sharpe, Marton V.; hide

    2017-01-01

    Optics for the next generation's high-resolution, high throughput x-ray telescope requires fabrication of well-formed lightweight mirror segments and their integration at arc-second precision. Recent advances in the fabrication of silicon mirrors developed at NASA/Goddard prompted us to develop a new method of mirror alignment and integration. In this method, stiff silicon mirrors are aligned quasi-kinematically and are bonded in an interlocking fashion to produce a "meta-shell" with large collective area. We address issues of aligning and bonding mirrors with this method and show a recent result of 4 seconds-of-arc for a single pair of mirrors tested at soft x-rays.

  2. High-energy x-ray grating-based phase-contrast radiography of human anatomy

    Science.gov (United States)

    Horn, Florian; Hauke, Christian; Lachner, Sebastian; Ludwig, Veronika; Pelzer, Georg; Rieger, Jens; Schuster, Max; Seifert, Maria; Wandner, Johannes; Wolf, Andreas; Michel, Thilo; Anton, Gisela

    2016-03-01

    X-ray grating-based phase-contrast Talbot-Lau interferometry is a promising imaging technology that has the potential to raise soft tissue contrast in comparison to conventional attenuation-based imaging. Additionally, it is sensitive to attenuation, refraction and scattering of the radiation and thus provides complementary and otherwise inaccessible information due to the dark-field image, which shows the sub-pixel size granularity of the measured object. Until recent progress the method has been mainly limited to photon energies below 40 keV. Scaling the method to photon energies that are sufficient to pass large and spacious objects represents a challenging task. This is caused by increasing demands regarding the fabrication process of the gratings and the broad spectra that come along with the use of polychromatic X-ray sources operated at high acceleration voltages. We designed a setup that is capable to reach high visibilities in the range from 50 to 120 kV. Therefore, spacious and dense parts of the human body with high attenuation can be measured, such as a human knee. The authors will show investigations on the resulting attenuation, differential phase-contrast and dark-field images. The images experimentally show that X-ray grating-based phase-contrast radiography is feasible with highly absorbing parts of the human body containing massive bones.

  3. Implementation of digital multiplexing for high resolution X-ray detector arrays.

    Science.gov (United States)

    Sharma, P; Swetadri Vasan, S N; Titus, A H; Cartwright, A N; Bednarek, D R; Rudin, S

    2012-01-01

    We describe and demonstrate for the first time the use of the novel Multiple Module Multiplexer (MMMIC) for a 2×2 array of new electron multiplying charge coupled device (EMCCD) based x-ray detectors. It is highly desirable for x-ray imaging systems to have larger fields of view (FOV) extensible in two directions yet to still be capable of doing high resolution imaging over regions-of-interest (ROI). The MMMIC achieves these goals by acquiring and multiplexing data from an array of imaging modules thereby enabling a larger FOV, and at the same time allowing high resolution ROI imaging through selection of a subset of modules in the array. MMMIC also supports different binning modes. This paper describes how a specific two stage configuration connecting three identical MMMICs is used to acquire and multiplex data from a 2×2 array of EMCCD based detectors. The first stage contains two MMMICs wherein each MMMIC is getting data from two EMCCD detectors. The multiplexed data from these MMMICs is then forwarded to the second stage MMMIC in the similar fashion. The second stage that has only one MMMIC gives the final 12 bit multiplexed data from four modules. This data is then sent over a high speed Camera Link interface to the image processing computer. X-ray images taken through the 2×2 array of EMCCD based detectors using this two stage configuration of MMMICs are shown successfully demonstrating the concept.

  4. High-resolution X-ray absorption spectroscopy of iron carbonyl complexes

    OpenAIRE

    Atkins, A.J.; Bauer, M; Jacob, C.R.

    2015-01-01

    We apply high-energy-resolution fluorescence-detected (HERFD) X-ray absorption near-edge spectroscopy (XANES) to study iron carbonyl complexes. Mono-, bi-, and tri-nuclear carbonyl complexes and pure carbonyl complexes as well as carbonyl complexes containing hydrocarbon ligands are considered. The HERFD-XANES spectra reveal multiple pre-edge peaks with individual signatures for each complex, which could not be detected previously with conventional XANES spectroscopy. These peaks are assigned...

  5. High count-rate study of two TES x-ray microcalorimeters with different transition temperatures

    Science.gov (United States)

    Lee, Sang-Jun; Adams, Joseph S.; Bandler, Simon R.; Betancourt-Martinez, Gabriele L.; Chervenak, James A.; Eckart, Megan E.; Finkbeiner, Fred M.; Kelley, Richard L.; Kilbourne, Caroline A.; Porter, Frederick S.; Sadleir, John E.; Smith, Stephen J.; Wassell, Edward J.

    2017-10-01

    We have developed transition-edge sensor (TES) microcalorimeter arrays with high count-rate capability and high energy resolution to carry out x-ray imaging spectroscopy observations of various astronomical sources and the Sun. We have studied the dependence of the energy resolution and throughput (fraction of processed pulses) on the count rate for such microcalorimeters with two different transition temperatures (T c). Devices with both transition temperatures were fabricated within a single microcalorimeter array directly on top of a solid substrate where the thermal conductance of the microcalorimeter is dependent upon the thermal boundary resistance between the TES sensor and the dielectric substrate beneath. Because the thermal boundary resistance is highly temperature dependent, the two types of device with different T cs had very different thermal decay times, approximately one order of magnitude different. In our earlier report, we achieved energy resolutions of 1.6 and 2.3 eV at 6 keV from lower and higher T c devices, respectively, using a standard analysis method based on optimal filtering in the low flux limit. We have now measured the same devices at elevated x-ray fluxes ranging from 50 Hz to 1000 Hz per pixel. In the high flux limit, however, the standard optimal filtering scheme nearly breaks down because of x-ray pile-up. To achieve the highest possible energy resolution for a fixed throughput, we have developed an analysis scheme based on the so-called event grade method. Using the new analysis scheme, we achieved 5.0 eV FWHM with 96% throughput for 6 keV x-rays of 1025 Hz per pixel with the higher T c (faster) device, and 5.8 eV FWHM with 97% throughput with the lower T c (slower) device at 722 Hz.

  6. Highly efficient angularly resolving x-ray spectrometer optimized for absorption measurements with collimated sources

    Science.gov (United States)

    Šmíd, M.; Gallardo González, I.; Ekerfelt, H.; Björklund Svensson, J.; Hansson, M.; Wood, J. C.; Persson, A.; Mangles, S. P. D.; Lundh, O.; Falk, K.

    2017-06-01

    Highly collimated betatron radiation from a laser wakefield accelerator is a promising tool for spectroscopic measurements. Therefore, there is a requirement to create spectrometers suited to the unique properties of such a source. We demonstrate a spectrometer which achieves an energy resolution of 1800 ) and is angularly resolving the x-ray emission allowing the reference and spectrum to be recorded at the same time. The single photon analysis is used to significantly reduce the background noise. Theoretical performance of various configurations of the spectrometer is calculated by a ray-tracing algorithm. The properties and performance of the spectrometer including the angular and spectral resolution are demonstrated experimentally on absorption above the K-edge of a Cu foil backlit by a laser-produced betatron radiation x-ray beam.

  7. Lightweight and High-Resolution Single Crystal Silicon Optics for X-ray Astronomy

    Science.gov (United States)

    Zhang, William W.; Biskach, Michael P.; Chan, Kai-Wing; Mazzarella, James R.; McClelland, Ryan S.; Riveros, Raul E.; Saha, Timo T.; Solly, Peter M.

    2016-01-01

    We describe an approach to building mirror assemblies for next generation X-ray telescopes. It incorporates knowledge and lessons learned from building existing telescopes, including Chandra, XMM-Newton, Suzaku, and NuSTAR, as well as from our direct experience of the last 15 years developing mirror technology for the Constellation-X and International X-ray Observatory mission concepts. This approach combines single crystal silicon and precision polishing, thus has the potential of achieving the highest possible angular resolution with the least possible mass. Moreover, it is simple, consisting of several technical elements that can be developed independently in parallel. Lastly, it is highly amenable to mass production, therefore enabling the making of telescopes of very large photon collecting areas.

  8. High-Resolution X-Ray Scattering Topography Using Synchrotron Radiation Microbeam

    Science.gov (United States)

    Chikaura, Yoshinori; Suzuki, Yoshifumi; Kii, Hideki

    1994-02-01

    Although spatial resolution is the most essential factor determining the function of X-ray topography, it has not been improved in 30 years in spite of increasing requirements for highly-resolvable topography in materials science. X-ray scattering topography using a microbeam is a method capable of overcoming this resolution problem. Because the maximum resolution of an apparatus using a sealed-off tube is limited to 20 µ m, we designed and constructed scattering topography equipment using a synchrotron radiation microbeam. In the experiment, the slit system forms the microbeam 7 µ m in diameter. We observed a cellulose distribution in bamboo as a testing material. When the scanning step was 2 µ m, we attained spatial resolution less than 5 µ m.

  9. High-resolution x-ray scatter and reflectivity study of sputtered IR surfaces

    DEFF Research Database (Denmark)

    Christensen, Finn Erland; Abdali, S.; Hornstrup, Allan

    1993-01-01

    In recent years there has been an increased interest in the possible use of Ir as the reflecting surface in X-ray telescope programs. An X-ray study of such surfaces produced by sputtering of Ir on highly polished Zerodur flats is presented here. The study was performed using Fe K(alpha) 1 (6.......404 Kev) and Cu K(alpha) 1 (8.048 keV) and includes measurement of total external reflection and scattering. The scattering measurement was made with three different instruments arrangements; one employed a 1D position sensitive detector for low resolution studies giving approximately 30 arcsec resolution...... (FWHM), and the other two arrangements employed channel cut crystals providing resolutions (FWHM) of 5 arcsec and 1 arcsec, respectively at Cu K(alpha) 1. The reflectivity study revealed a very close correspondence with a theoretical model based on recently published optical constants. This important...

  10. High power, short pulses ultraviolet laser for the development of a new x-ray laser

    Energy Technology Data Exchange (ETDEWEB)

    Meixler, L.; Nam, C.H.; Robinson, J.; Tighe, W.; Krushelnick, K.; Suckewer, S.; Goldhar, J.; Seely, J.; Feldman, U.

    1989-04-01

    A high power, short pulse ultraviolet laser system (Powerful Picosecond-Laser) has been developed at the Princeton Plasma Physics Laboratory (PPPL) as part of experiments designed to generate shorter wavelength x-ray lasers. With the addition of pulse compression and a final KrF amplifier the laser output is expected to have reached 1/3-1/2 TW (10/sup 12/ watts) levels. The laser system, particularly the final amplifier, is described along with some initial soft x-ray spectra from laser-target experiments. The front end of the PP-Laser provides an output of 20--30 GW (10/sup 9/ watts) and can be focussed to intensities of /approximately/10/sup 16/ W/cm/sup 2/. Experiments using this output to examine the effects of a prepulse on laser-target interaction are described. 19 refs., 14 figs.

  11. Structured photocathodes for improved high-energy x-ray efficiency in streak cameras

    Energy Technology Data Exchange (ETDEWEB)

    Opachich, Y. P., E-mail: opachiyp@nv.doe.gov; Huffman, E.; Koch, J. A. [National Security Technologies, LLC, Livermore, California 94551 (United States); Bell, P. M.; Bradley, D. K.; Hatch, B.; Landen, O. L.; MacPhee, A. G.; Nagel, S. R. [Lawrence Livermore National Laboratory, Livermore, California 94551 (United States); Chen, N.; Gopal, A.; Udin, S. [Nanoshift LLC, Emeryville, California 94608 (United States); Feng, J. [Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Hilsabeck, T. J. [General Atomics, San Diego, California 92121 (United States)

    2016-11-15

    We have designed and fabricated a structured streak camera photocathode to provide enhanced efficiency for high energy X-rays (1–12 keV). This gold coated photocathode was tested in a streak camera and compared side by side against a conventional flat thin film photocathode. Results show that the measured electron yield enhancement at energies ranging from 1 to 10 keV scales well with predictions, and that the total enhancement can be more than 3×. The spatial resolution of the streak camera does not show degradation in the structured region. We predict that the temporal resolution of the detector will also not be affected as it is currently dominated by the slit width. This demonstration with Au motivates exploration of comparable enhancements with CsI and may revolutionize X-ray streak camera photocathode design.

  12. High aspect ratio gratings for X-ray phase contrast imaging

    Science.gov (United States)

    Mohr, Jürgen; Grund, Thomas; Kunka, Danays; Kenntner, Johannes; Leuthold, Juerg; Meiser, Jan; Schulz, Joachim; Walter, Marco

    2012-07-01

    Differential phase contrast X-ray imaging (DPCI) has gained a lot of interest in the past years. It is based on X-ray grating interferometry and the image quality is strongly dependant on the grating quality. Periodic line and space structures with periods in the micron range are required for the source and absorption grating. In case of energies > 30 keV their height should be larger than 100 μm resulting in aspect ratios of more than 100. Deep X-ray lithography and gold electroforming (LIGA technology) is used to fabricate these challenging structures. After resist, design and process optimization gratings with 2.4 μm period have been electroformed up to 120 μm, Visibilities of up to 70% for 29 keV and up to 20% for 52 keV have been achieved for monochromatic synchrotron light. Structures with larger periods could be manufactured up to 200 μm; further increase of the height and the gratings quality is possible yielding to high performance gratings also for high energies.

  13. Design of High Resolution Soft X-Ray Microcalorimeters Using Magnetic Penetration Thermometers

    Science.gov (United States)

    Busch. Sarah; Balvin, Manuel; Bandler, Simon; Denis, Kevin; Finkbeiner, Fred; Porst, Jan-Patrick; Sadlier, Jack; Smith, Stephen; Stevenson, Thomas

    2012-01-01

    We have designed high-resolution soft x-ray microcalorimeters using magnetic penetration thermometers (MPTs) in an array of pixels covering a total of 2 square centimeters to have a resolving power of 300 at energies around 300 eV. This performance is desirable for studying the soft x-ray background from the warm hot intergalactic medium. MPT devices have small sensor heat capacity and high responsivities, which makes them excellent detector technology for attempting to attain sub-eV resolution. We are investigating the feasibility of pixels with absorbers that are 625 x 625 square micrometers, up to 1 x 1 square millimeters in area and 0.35 micrometer thick and thinner. Our tests have shown that suspended gold absorbers 0.35 micrometers thick (RRR = 6.7) are feasible to fabricate. We modeled the thermal diffusion from such thin gold over the size of a 625 x 625 square micrometer absorber, and conclude that the effect of the thermalization on the resolution of a 300 eV photon is an additional approximately 0.2 eV FWHM of broadening. We discuss the thermal effects of small absorber attachment sterns on solid substrate, as well as considerations for multiplexed readout. We will present the progress we have made towards building and testing this soft x-ray detector.

  14. Position detection accuracy of a novel linac-mounted intrafractional x-ray imaging system.

    Science.gov (United States)

    Fast, Martin F; Krauss, Andreas; Oelfke, Uwe; Nill, Simeon

    2012-01-01

    The authors have developed a system that monitors intrafractional target motion perpendicular to the treatment beam with the aid of radioopaque markers by means of separating kV image and megavoltage (MV) treatment field on a single flat-panel detector. They equipped a research Siemens Artiste linear accelerator (linac) with a 41 × 41 cm(2) a-Si flat-panel detector underneath the treatment head. The in-line geometry allows kV (imaging) and MV (treatment) beams to share closely aligned beam axes. The kV source, usually mounted directly across from the flat-panel imager, was retracted toward the gantry by 13 cm to intentionally misalign kV and MV beams, resulting in a geometric separation of MV treatment field and kV image on the detector. Two consecutive images acquired within 140 ms (the first with MV-only and the second with kV and MV signal) were subtracted to generate a kV-only image. The images were then analyzed "online" with an automated threshold-based marker detection algorithm. They employed a 3D and a 4D phantom equipped with either a single radioopaque marker or three Calypso beacons to mimic respiratory motion. Measured room positions were either cross-referenced with a phantom voltage signal (single marker) or the Calypso system. The accuracy of the back-projection (from detected marker positions into room coordinates) was verified by a simulation study. A phantom study has demonstrated that the imaging framework is capable of automatically detecting marker positions and sending this information to the tracking tool at an update rate of 7.14 Hz. The system latency is 86.9 ± 1.0 ms for single marker detection in the absence of MV radiation. In the presence of a circular MV field of 5 cm diameter, the latency is 87.1 ± 0.9 ms. The total RMS position detection accuracy is 0.20 mm (without MV radiation) and 0.23 mm (with MV). Based on the evaluated motion patterns and MV field size, the positional accuracy and system latency indicate that

  15. Soft x-ray blazed transmission grating spectrometer with high resolving power and extended bandpass

    Science.gov (United States)

    Heilmann, Ralf K.; Bruccoleri, Alexander Robert; Schattenburg, Mark

    2016-04-01

    A number of high priority questions in astrophysics can be addressed by a state-of-the-art soft x-ray grating spectrometer, such as the role of Active Galactic Nuclei in galaxy and star formation, characterization of the Warm-Hot Intergalactic Medium and the “missing baryon” problem, characterization of halos around the Milky Way and nearby galaxies, as well as stellar coronae and surrounding winds and disks. An Explorer-scale, large-area (> 1,000 cm2), high resolving power (R = λ/Δλ > 3,000) soft x-ray grating spectrometer is highly feasible based on Critical-Angle Transmission (CAT) grating technology. Still significantly higher performance can be provided by a CAT grating spectrometer on an X-ray-Surveyor-type mission. CAT gratings combine the advantages of blazed reflection gratings (high efficiency, use of higher diffraction orders) with those of conventional transmission gratings (low mass, relaxed alignment tolerances and temperature requirements, transparent at higher energies) with minimal mission resource requirements. They are high-efficiency blazed transmission gratings that consist of freestanding, ultra-high aspect-ratio grating bars fabricated from silicon-on-insulator (SOI) wafers using advanced anisotropic dry and wet etch techniques. Blazing is achieved through grazing-incidence reflection off the smooth grating bar sidewalls. The reflection properties of silicon are well matched to the soft x-ray band. Nevertheless, CAT gratings with sidewalls made of higher atomic number elements allow extension of the CAT grating principle to higher energies and larger dispersion angles. We show x-ray data from metal-coated CAT gratings and demonstrate efficient blazing to higher energies and larger blaze angles than possible with silicon alone. We also report on measurements of the resolving power of a breadboard CAT grating spectrometer consisting of a Wolter-I slumped-glass focusing mirror pair from Goddard Space Flight Center and CAT gratings, to be

  16. Bystander effect between zebrafish embryos in vivo induced by high-dose X-rays.

    Science.gov (United States)

    Choi, V W Y; Ng, C Y P; Kobayashi, A; Konishi, T; Suya, N; Ishikawa, T; Cheng, S H; Yu, K N

    2013-06-18

    We employed embryos of the zebrafish, Danio rerio, for our studies on the in vivo bystander effect between embryos irradiated with high-dose X-rays and naive unirradiated embryos. The effects on the naive whole embryos were studied through quantification of apoptotic signals at 25 h post fertilization (hpf) through the terminal dUTP transferase-mediated nick end-labeling (TUNEL) assay followed by counting the stained cells under a microscope. We report data showing that embryos at 5 hpf subjected to a 4-Gy X-ray irradiation could release a stress signal into the medium, which could induce a bystander effect in partnered naive embryos sharing the same medium. We further demonstrated that this bystander effect (induced through partnering) could be successfully suppressed through the addition of the nitric oxide (NO) scavenger 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (cPTIO) into the medium but not through the addition of the CO liberator tricarbonylchloro(glycinato)ruthenium(II) (CORM-3). This shows that NO was involved in the bystander response between zebrafish embryos induced through X-ray irradiation. We also report data showing that the bystander effect could be successfully induced in naive embryos by introducing them into the irradiated embryo conditioned medium (IECM) alone, i.e., without partnering with the irradiated embryos. The IECM was harvested from the medium that had conditioned the zebrafish embryos irradiated at 5 hpf with 4-Gy X-ray until the irradiated embryos developed into 29 hpf. NO released from the irradiated embryos was unlikely to be involved in the bystander effect induced through the IECM because of the short life of NO. We further revealed that this bystander effect (induced through IECM) was rapidly abolished through diluting the IECM by a factor of 2× or greater, which agreed with the proposal that the bystander effect was an on/off response with a threshold.

  17. Insights into the High-Mass X-ray Binary Population of the Magellanic Clouds

    Science.gov (United States)

    Antoniou, V.; Zezas, A.; Hatzidimitriou, D.; Kalogera, V.

    2013-09-01

    In contrast to the Small Magellanic Cloud (SMC), the Large Magellanic Cloud (LMC), our nearest starforming galaxy with metallicity between the Galaxy and the SMC, has received little attention in X-rays so far. With the aim to compare the accreting X-ray binary (XRB) populations in two of our nearest star-forming galaxies, we recently compiled the most complete census of high-mass X-ray binaries (HMXBs) in the LMC. We found 43 members of which 13 are XRB pulsars, while we also identified their most likely optical counterpart (previously, half of these sources lacked an identification). Using this census, we investigated the link between the young accreting XRBs and their parent stellar populations. It was known that HMXBs can be used as star-formation (SF) rate indicators, but these first studies have been focused only on bright systems (Galaxy: >1038 erg s-1, Magellanic Clouds: >1036 erg s-1) and SF values for the whole galaxy. By including Magellanic Cloud sources with X-ray luminosities at least two order of magnitudes fainter than the above limits and by utilizing the detailed, spatially resolved, SF history maps of these galaxies, we were able to provide observational constraints on ill-understood parameters related to their formation and evolution (such as the kick velocities imparted into the neutron star during the supernova explosion) and to derive their formation efficiency. This work was mainly supported by the National Aeronautics and Space Administration under Grant No. NNX10AH47G issued through the Astrophysics Data Analysis Program.

  18. [Neutron Dosimetry System Using CR-39 for High-energy X-ray Radiation Therapy].

    Science.gov (United States)

    Yabuta, Kazutoshi; Monzen, Hajime; Tamura, Masaya; Tsuruta, Takao; Itou, Tetsuo; Nohtomi, Akihiro; Nishimura, Yasumasa

    2014-01-01

    Neutrons are produced during radiation treatment by megavolt X-ray energies. However, it is difficult to measure neutron dose especially just during the irradiation. Therefore, we have developed a system for measuring neutrons with the solid state track detector CR-39, which is free from the influence of the X-ray beams. The energy spectrum of the neutrons was estimated by a Monte Carlo simulation method, and the estimated neutron dose was corrected by the contribution ratio of each energy. Pit formation rates of CR-39 ranged from 2.3 x 10(-3) to 8.2 x 10(-3) for each detector studied. According to the estimated neutron energy spectrum, the energy values for calibration were 144 keV and 515keV, and the contribution ratios were approximately 40:60 for 10 MV photons and 20:70 for photons over 15 MV. Neutron doses measured in the center of a high-energy X-ray field were 0.045 mSv/Gy for a 10 MV linear accelerator and 0.85 mSv/Gy for a 20 MV linear accelerator. We successfully developed the new neutron dose measurement system using the solid track detector, CR-39. This on-time neutron measurement system allows users to measure neutron doses produced in the radiation treatment room more easily.

  19. Heat transfer issues in high-heat-load synchrotron x-ray beams

    Energy Technology Data Exchange (ETDEWEB)

    Khounsary, A.M.; Mills, D.M.

    1994-09-01

    In this paper, a short description of the synchrotron radiation x-ray sources and the associated power loads is given, followed by a brief description of typical synchrotron components and their heat load. It is emphasized that the design goals for most of these components is to limit (a) temperature, (b) stresses, or (c) strains in the system. Each design calls for a different geometry, material selection, and cooling scheme. Cooling schemes that have been utilized so far are primarily single phase and include simple macrochannel cooling, microchannel cooling, contact cooling, pin-post cooling, porous-flow cooling, jet cooling, etc. Water, liquid metals, and various cryogenic coolants have been used. Because the trend in x-ray beam development is towards brighter (i.e., more powerful) beams and assuming that no radical changes in the design of x-ray generating machines occurs in the next few years, it is fair to state that the utilization of various effective cooling schemes and, in particular, two-phase flow (e.g., subcooled boiling) warrants further investigation. This, however, requires a thorough examination of stability and reliability of two-phase flows for high-heat-flux components operating in ultrahigh vacuum with stringent reliability requirements.

  20. A directly converting high-resolution intra-oral X-ray imaging sensor

    CERN Document Server

    Spartiotis, K; Schulman, T; Puhakka, K; Muukkonen, K

    2003-01-01

    A digital intra-oral X-ray imaging sensor with an active area of 3.6x2.9 cm sup 2 and consisting of six charge-integrating CMOS signal readout circuits bump bonded to one high-resistivity silicon pixel detector has been developed and tested. The pixel size is 35 mu m. The X-rays entering the sensor window are converted directly to electrical charge in the depleted detector material yielding minimum lateral signal spread and maximum image sharpness. The signal charge is collected on the gates of the input field effect transistors of the CMOS signal readout circuits. The analog signal readout is performed by multiplexing in the current mode independent of the signal charge collection enabling multiple readout cycles with negligible dead time and thus imaging with wide dynamic range. Since no intermediate conversion material of X-rays to visible light is needed, the sensor structure is very compact. The analog image signals are guided from the sensor output through a thin cable to signal processing, AD conversio...

  1. The UCSD high energy X-ray timing experiment cosmic ray particle anticoincidence detector

    Science.gov (United States)

    Hink, P. L.; Rothschild, R. E.; Pelling, M. R.; Macdonald, D. R.; Gruber, D. E.

    1991-01-01

    The HEXTE, part of the X-Ray Timing Explorer (XTE), is designed to make high sensitivity temporal and spectral measurements of X-rays with energies between 15 and 250 keV using NaI/CsI phoswich scintillation counters. To achieve the required sensitivity it is necessary to provide anticoincidence of charged cosmic ray particles incident upon the instrument, some of which interact to produce background X-rays. The proposed cosmic ray particle anticoincidence shield detector for HEXTE uses a novel design based on plastic scintillators and wavelength-shifter bars. It consists of five segments, each with a 7 mm thick plastic scintillator, roughly 50 cm x 50 cm in size, coupled to two wavelength-shifter bars viewed by 1/2 inch photomultiplier tubes. These segments are configured into a five-sided, box-like structure around the main detector system. Results of laboratory testing of a model segment, and calculations of the expected performance of the flight segments and particle anticoincidence detector system are presented to demonstrate that the above anticoincidence detector system satisfies its scientific requirements.

  2. Beam collimation with polycapillary x-ray optics for high contrast high resolution monochromatic imaging.

    Science.gov (United States)

    Sugiro, Francisca R; Li, Danhong; MacDonald, C A

    2004-12-01

    Monochromatic imaging can provide better contrast and resolution than conventional broadband radiography. In broadband systems, low energy photons do not contribute to the image, but are merely absorbed, while high energy photons produce scattering that degrades the image. By tuning to the optimal energy, one can eliminate undesirable lower and higher energies. Monochromatization is achieved by diffraction from a single crystal. A crystal oriented to diffract at a particular energy, in this case the characteristic line energy, diffracts only those photons within a narrow range of angles. The resultant beam from a divergent source is nearly parallel, but not very intense. To increase the intensity, collimation was performed with polycapillary x-ray optics, which can collect radiation from a divergent source and redirect it into a quasi parallel beam. Contrast and resolution measurements were performed with diffracting crystals with both high and low angular acceptance. Testing was first done at 8 keV with an intense copper rotating anode x-ray source, then 17.5 keV measurements were made with a low power molybdenum source. At 8 keV, subject contrast was a factor of five higher than for the polychromatic case. At 17.5 keV, monochromatic contrast was two times greater than the conventional polychromatic contrast. The subject contrasts measured at both energies were in good agreement with theory. An additional factor of two increase in contrast, for a total gain of four, is expected at 17.5 keV from the removal of scatter. Scatter might be simply removed using an air gap, which does not degrade resolution with a parallel beam.

  3. High-Resolution Detector for At-Wavelength Metrology of X-Ray Optics Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Since the launch of the first X-ray focusing telescope in 1963, the development of grazing incidence X-ray optics has been crucial to the development of the field of...

  4. High Throughput Soft X-Ray Filters with Enhanced IR-Rejection Project

    Data.gov (United States)

    National Aeronautics and Space Administration — To fully realize the advances NASA has made in x-ray microcalorimeter detectors, x-ray filters with enhanced out-of-band performance are needed. Blocking filters are...

  5. Development Of Position-sensitive Cadmium Zinc Telluride Detectors For High-energy X-ray Astrophysics

    CERN Document Server

    Slavis, K R

    2001-01-01

    This dissertation reports on the studies of an orthogonal cross-strip CdZnTe detector for high-energy X-ray (20–250 keV) astrophysics applications. The intrinsic three-dimensional detector response and the effectiveness of using various shielding techniques at balloon altitudes are investigated. This detector has great promise for use as the imaging detector of a large- area, coded-mask instrument in an all-sky high-energy X- ray survey or as the focal-plane detector for an X-ray focusing telescope (Constellation-X) for high throughput, high resolution X-ray spectroscopy (6–40 keV). The most recent hard X-ray all-sky survey was conducted by HEAO-1/A4 in 1978, and one has not been conducted since then due to performance limitations of available X-ray detector technology. The next generation instruments need to have sub-degree angular resolution, good sensitivity in the hard X-ray band (3σ sensitivity to sub- mCrab), and few keV energy resolution. This performance is demonstrated u...

  6. Radiation effects for high-energy protons and X-ray in integrated circuits

    Energy Technology Data Exchange (ETDEWEB)

    Silveira, M.A.G.; Santos, R.B.B. [Centro Universitario da FEI, Sao Bernardo do Campo, SP (Brazil); Medina, N.H.; Added, N.; Tabacniks, M.H. [Universidade de Sao Paulo (IF/USP), SP (Brazil). Inst. de Fisica; Lima, J.A. de [Universidade Federal de Santa Catarina (UFSC), Florianopolis, SC (Brazil); Cirne, K.H. [Empresa Brasileira de Aeronautica S.A. (EMBRAER), Sao Jose dos Campos, SP (Brazil)

    2012-07-01

    Full text: Electronic circuits are strongly influenced by ionizing radiation. The necessity to develop integrated circuits (IC's) featuring radiation hardness is largely growing to meet the stringent environment in space electronics [1]. This work aims to development a test platform to qualify electronic devices under the influence of high radiation dose, for aerospace applications. To understand the physical phenomena responsible for changes in devices exposed to ionizing radiation several kinds of radiation should then be considered, among them heavy ions, alpha particles, protons, gamma and X-rays. Radiation effects on the ICs are usually divided into three categories: Total Ionizing Dose (TID), a cumulative dose that shifts the threshold voltage and increases transistor's off-state current; Single Events Effects (SEE), a transient effect which can deposit charge directly into the device and disturb the properties of electronic circuits and Displacement Damage (DD) which can change the arrangement of the atoms in the lattice [2]. In this study we are investigating the radiation effects in rectangular-gate and circular-gate MOSFETs, manufactured with standard CMOS fabrication process, using particle beams produced in electrostatic tandem accelerators and X-rays. Initial tests for TID effects were performed using the 1.7 MV 5SDH tandem Pelletron accelerator of the Instituto de Fisica da USP with a proton beam of 2.6 MeV. The devices were exposed to different doses, varying the beam current, and irradiation time with the accumulated dose reaching up to Grad. To study the effect of X-rays on the electronic devices, an XRD-7000 (Shimadzu) X-ray setup was used as a primary X-ray source. The devices were irradiated with a total dose from krad to Grad using different dose rates. The results indicate that changes of the I-V characteristic curve are strongly dependents on the geometry of the devices. [1] Duzellier, S., Aerospace Science and Technology 9, p. 93

  7. Topics in High-Energy Astrophysics: X-ray Time Lags and Gamma-ray Flares

    Science.gov (United States)

    Kroon, John J.

    2016-03-01

    The Universe is host to a wide variety of high-energy processes that convert gravitational potential energy or rest-mass energy into non-thermal radiation such as bremsstrahlung and synchrotron. Prevailing models of X-ray emission from accreting Black Hole Binaries (BHBs) struggle to simultaneously fit the quiescent X-ray spectrum and the transients which result in the phenomenon known as X-ray time lags. And similarly, classical models of diffusive shock acceleration in pulsar wind nebulae fail to explain the extreme particle acceleration in very short timescales as is inferred from recent gamma-ray flares from the Crab nebula. In this dissertation, I develop new exact analytic models to shed light on these intriguing processes. I take a fresh look at the formation of X-ray time lags in compact sources using a new mathematical approach in which I obtain the exact Green's function solution. The resulting Green's function allows one to explore a variety of injection scenarios, including both monochromatic and broadband (bremsstrahlung) seed photon injection. I obtain the exact solution for the dependence of the time lags on the Fourier frequency, for both homogeneous and inhomogeneous clouds. The model can successfully reproduce both the observed time lags and the quiescent X-ray spectrum using a single set of coronal parameters. I show that the implied coronal radii in the new model are significantly smaller than those obtained in the Monte Carlo simulations, hence greatly reducing the coronal heating problem. Recent bright gamma-ray flares from the Crab nebula observed by AGILE and Fermi reaching GeV energies and lasting several days challenge the contemporary model for particle acceleration in pulsar wind nebulae, specifically the diffusive shock acceleration model. Simulations indicate electron/positron pairs in the Crab nebula pulsar wind must be accelerated up to PeV energies in the presence of ambient magnetic fields with strength B ~100 microG. No

  8. A CCD area detector for X-ray diffraction under high pressure for ...

    Indian Academy of Sciences (India)

    Details of a two-dimensional X-ray area detector developed using a charge coupled device, a image intensifier and a fibre optic taper are given. The detector system is especially optimized for angle dispersive X-ray diffraction set up using rotating anode generator as X-ray source. The performance of this detector was ...

  9. A CCD area detector for X-ray diffraction under high pressure for ...

    Indian Academy of Sciences (India)

    Unknown

    Abstract. Details of a two-dimensional X-ray area detector developed using a charge coupled device, a image intensifier and a fibre optic taper are given. The detector system is especially optimized for angle dispersive X-ray diffraction set up using rotating anode generator as X-ray source. The performance of this detector ...

  10. Suzaku observation of the eclipsing high mass X-ray binary pulsar ...

    Indian Academy of Sciences (India)

    Jincy Devasia

    2018-02-09

    Feb 9, 2018 ... The correlated variations in the spectral parameters indicate towards the presence of clumps in the stellar wind of the companion star accounting for the absorption of low energy X-rays in some time segments. Keywords. X-ray: neutron stars—X-ray binaries: individual (XTE J1855-026). 1. Introduction.

  11. High resolution x-ray and gamma ray imaging using diffraction lenses with mechanically bent crystals

    Science.gov (United States)

    Smither, Robert K [Hinsdale, IL

    2008-12-23

    A method for high spatial resolution imaging of a plurality of sources of x-ray and gamma-ray radiation is provided. High quality mechanically bent diffracting crystals of 0.1 mm radial width are used for focusing the radiation and directing the radiation to an array of detectors which is used for analyzing their addition to collect data as to the location of the source of radiation. A computer is used for converting the data to an image. The invention also provides for the use of a multi-component high resolution detector array and for narrow source and detector apertures.

  12. The high-precision x-ray tomograph for quality control of the ATLAS MDT muon spectrometer

    CERN Document Server

    Drakoulakos, D G; Maugain, J M; Rohrbach, F; Sedykh, Yu

    1997-01-01

    For the Large Hadron Collider (LHC) of the next millennium, a large general-purpose high-energy physics experiment, the ATLAS project, is being designed by a world-wide collaboration. One of its detectors, the ATLAS muon tracking detector, the MDT project, is on the scale of a very large industrial project: the design, the construction and assembly of twelve hundred large muon drift chambers are aimed at producing an exceptional quality in terms of accuracy, material reliability, assembly, and monitoring. This detector, based on the concept of very high mechanical precision required by the physics goals, will use tomography as a quality control platform. An X-ray tomograph prototype, monitored by a set of interferometers, has been developed at CERN to provide high-quality control of the MDT chambers which will be built in the collaborating institutes of the ATLAS project. First results have been obtained on MDT prototypes showing the validity of the X-ray tomograph approach for mechanical control of the detec...

  13. High-mass X-ray binaries and the cosmic 21-cm signal: impact of host galaxy absorption

    Science.gov (United States)

    Das, Arpan; Mesinger, Andrei; Pallottini, Andrea; Ferrara, Andrea; Wise, John H.

    2017-07-01

    By heating the intergalactic medium (IGM) before reionization, X-rays are expected to play a prominent role in the early Universe. The cosmic 21-cm signal from this 'epoch of heating' (EoH) could serve as a clean probe of high-energy processes inside the first galaxies. Here, we improve on prior estimates of this signal by using high-resolution hydrodynamic simulations to calculate the X-ray absorption due to the interstellar medium (ISM) of the host galaxy, typically residing in haloes with mass 107.5-8.5 M⊙ at z ˜ 8-15. X-rays absorbed inside the host galaxy are unable to escape into the IGM and contribute to the EoH. We find that the X-ray opacity through these galaxies can be approximated by a metal-free ISM with a typical column density of log [N_{H I}/cm^{-2}] = 21.4^{+0.40}_{-0.65}. We compute the resulting 21-cm signal by combining these ISM opacities with public spectra of high-mass X-ray binaries (thought to be important X-ray sources in the early Universe). Our results support 'standard scenarios' in which the X-ray heating of the IGM is inhomogeneous, and occurs before the bulk of reionization. The large-scale (k ˜ 0.1 Mpc-1) 21-cm power reaches a peak of ≈100 mK2 at z ˜ 10-15, with the redshift depending on the cosmic star formation history. Our main results can be reproduced by approximating the X-ray emission from high-mass X-ray binaries by a power law with energy index α ≈ 1, truncated at energies below 0.5 keV.

  14. Direct navigation on 3D rotational x-ray data acquired with a mobile propeller C-arm: accuracy and application in functional endoscopic sinus surgery

    NARCIS (Netherlands)

    van de Kraats, Everine B.; Carelsen, Bart; Fokkens, Wytske J.; Boon, Sjirk N.; Noordhoek, Niels; Niessen, Wiro J.; van Walsum, Theo

    2005-01-01

    Recently, three-dimensional (3D) rotational x-ray imaging has been combined with navigation technology, enabling direct 3D navigation for minimally invasive image guided interventions. In this study, phantom experiments are used to determine the accuracy of such a navigation set-up for a mobile

  15. Accuracy and the influence of marrow fat on quantitative CT and dual-energy X-ray absorptiometry measurements of the femoral neck in vitro

    NARCIS (Netherlands)

    J.-W. Kuiper (Jan-Willem); C. van Kuijk (Cornelis); J.L. Grashuis (Jan); A.G.H. Ederveen (Antwan); H.E. Schütte (Henri)

    1996-01-01

    markdownabstractAbstract Bone mineral measurements with quantitative computed tomography (QCT) and dual-energy X-ray absorptiometry (DXA) were compared with chemical analysis (ChA) to determine (1) the accuracy and (2) the influence of bone marrow fat. Total bone mass of 19 human femoral necks in

  16. Dynamic crystal rotation resolved by high-speed synchrotron X-ray Laue diffraction.

    Science.gov (United States)

    Huang, J W; E, J C; Huang, J Y; Sun, T; Fezzaa, K; Luo, S N

    2016-05-01

    Dynamic compression experiments are performed on single-crystal Si under split Hopkinson pressure bar loading, together with simultaneous high-speed (250-350 ns resolution) synchrotron X-ray Laue diffraction and phase-contrast imaging. A methodology is presented which determines crystal rotation parameters, i.e. instantaneous rotation axes and angles, from two unindexed Laue diffraction spots. Two-dimensional translation is obtained from dynamic imaging by a single camera. High-speed motion of crystals, including translation and rotation, can be tracked in real time via simultaneous imaging and diffraction.

  17. Dynamic crystal rotation resolved by high-speed synchrotron X-ray Laue diffraction

    Energy Technology Data Exchange (ETDEWEB)

    Huang, J. W.; E, J. C.; Huang, J. Y.; Sun, T.; Fezzaa, K.; Luo, S. N.

    2016-03-30

    Dynamic compression experiments are performed on single-crystal Si under split Hopkinson pressure bar loading, together with simultaneous high-speed (250–350 ns resolution) synchrotron X-ray Laue diffraction and phase-contrast imaging. A methodology is presented which determines crystal rotation parameters,i.e.instantaneous rotation axes and angles, from two unindexed Laue diffraction spots. Two-dimensional translation is obtained from dynamic imaging by a single camera. High-speed motion of crystals, including translation and rotation, can be tracked in real timeviasimultaneous imaging and diffraction.

  18. Scanning three-dimensional x-ray diffraction microscopy using a high-energy microbeam

    Energy Technology Data Exchange (ETDEWEB)

    Hayashi, Y., E-mail: y-hayashi@mosk.tytlabs.co.jp; Hirose, Y.; Seno, Y. [Toyota Central R& D Toyota Central R& D Labs., Inc., 41-1 Nagakute Aichi 480-1192 Japan (Japan)

    2016-07-27

    A scanning three-dimensional X-ray diffraction (3DXRD) microscope apparatus with a high-energy microbeam was installed at the BL33XU Toyota beamline at SPring-8. The size of the 50 keV beam focused using Kirkpatrick-Baez mirrors was 1.3 μm wide and 1.6 μm high in full width at half maximum. The scanning 3DXRD method was tested for a cold-rolled carbon steel sheet sample. A three-dimensional orientation map with 37 {sup 3} voxels was obtained.

  19. Structural studies coupling X-ray diffraction and high-energy X-ray scattering in the UO2(2+)-HBr(aq) system.

    Science.gov (United States)

    Wilson, Richard E; Skanthakumar, S; Cahill, C L; Soderholm, L

    2011-11-07

    The structural chemistry of uranium(VI) in concentrated aqueous hydrobromic acid solutions was investigated using both single crystal X-ray diffraction and synchrotron-based high-energy X-ray scattering (HEXS) to reveal the structure of the uranium(VI) complexes in solution prior to crystallization. The crystal structures of a series of uranyl tetrabromide salts are reported, including Cs(2)UO(2)Br(4), Rb(2)UO(2)Br(4)·2H(2)O, K(2)UO(2)Br(4)·2H(2)O, and (NH(4))(2)UO(2)Br(4)·2H(2)O, as well as a molecular dimer of uranium(VI), (UO(2))(2)(OH)(2)Br(2)(H(2)O)(4). Limited correspondence exists between the structures observed in the solid state and those in solution. Quantitative analysis of the HEXS data show an average U-Br coordination number of 1.9(2) in solution, in contrast to the U-Br coordination number of 4 in the solid salts. © 2011 American Chemical Society

  20. Relative accuracy testing of an X-ray fluorescence-based mercury monitor at coal-fired boilers

    Energy Technology Data Exchange (ETDEWEB)

    K. James Hay; Bruce E. Johnsen; Paul R. Ginochio; John A. Cooper [U.S. Army Engineer Research and Development Center, Champaign, IL (United States). Construction Engineering Research Laboratory

    2006-05-15

    The relative accuracy (RA) of a newly developed mercury continuous emissions monitor, based on X-ray fluorescence, was determined by comparing analysis results at coal-fired plants with two certified reference methods (American Society for Testing and Materials (ASTM) Method D6784-02 and U.S. Environment Protection Agency (EPA) Method 29). During the first determination, the monitor had an RA of 25% compared with ASTM Method D6784-02 (Ontario Hydro Method). However, the Ontario Hydro Method performed poorly, because the mercury concentrations were near the detection limit of the reference method. The mercury in this exhaust stream was primarily elemental. The second test was performed at a U.S. Army boiler against EPA Reference Method 29. Mercury and arsenic were spiked because of expected low mercury concentrations. The monitor had an RA of 16% for arsenic and 17% for mercury, meeting RA requirements of EPA Performance Specification 12a. The results suggest that the sampling stream contained significant percentages of both elemental and oxidized mercury. The monitor was successful at measuring total mercury in particulate and vapor forms. 25 refs., 8 figs., 3 tabs.

  1. High-intensity X-rays interaction with matter processes in plasmas, clusters, molecules and solids

    CERN Document Server

    Hau-Riege, Stefan P

    2012-01-01

    Filling the need for a book bridging the effect of matter on X-ray radiation and the interaction of x-rays with plasmas, this monograph provides comprehensive coverage of the topic. As such, it presents and explains such powerful new X-ray sources as X-ray free-electron lasers, as well as short pulse interactions with solids, clusters, molecules, and plasmas, and X-ray matter interactions as a diagnostic tool. Equally useful for researchers and practitioners working in the field.

  2. On filtration for high-energy phase-contrast x-ray imaging

    Science.gov (United States)

    Riess, Christian; Mohamed, Ashraf; Hinshaw, Waldo; Fahrig, Rebecca

    2015-03-01

    Phase-sensitive x-ray imaging promises unprecedented soft-tissue contrast and resolution. However, several practical challenges have to be overcome when using the setup in a clinical environment. The system design that is currently closest to clinical use is the grating-based Talbot-Lau interferometer (GBI).1-3 The requirements for patient imaging are low patient dose, fast imaging time, and high image quality. For GBI, these requirements can be met most successfully with a narrow energy width, high- ux spectrum. Additionally, to penetrate a human-sized object, the design energy of the system has to be well above 40 keV. To our knowledge, little research has been done so far to investigate optimal GBI filtration at such high x-ray energies. In this paper, we study different filtration strategies and their impact on high-energy GBI. Specifically, we compare copper filtration at low peak voltage with equal-absorption, equal-imaging time K-edge filtration of spectra with higher peak voltage under clinically realistic boundary conditions. We specifically focus on a design energy of 59 keV and investigate combinations of tube current, peak voltage, and filtration that lead to equal patient absorption. Theoretical considerations suggest that the K edge of tantalum might provide a transmission pocket at around 59 keV, yielding a well-shaped spectrum. Although one can observe a slight visibility benefit when using tungsten or tantalum filtration, experimental results indicate that visibility benefits most from a low x-ray tube peak voltage.

  3. Flash x-ray observations of cavitation in cadaver thighs caused by high-velocity bullets.

    Science.gov (United States)

    Boyer, C N; Holland, G E; Seely, J F

    2005-12-01

    The purpose of this study was to record flash x-ray images of cavitation in human cadaver thighs caused by the passage of high-velocity bullets. The images are an initial step for understanding the cavitation process in human tissue and for implementing a better definition of extensive tissue injury. Bullets were fired through the mid-thighs of 13 cadaver legs. The bullets were of two calibers, 7.62-mm full metal jacket boat tail with strike velocities in the range of 794 m/s to 880 m/s (10 thighs) and 5.70 mm full metal jacket with velocities in the range of 973 m/s to 992 m/s (3 thighs). Short duration (35 ns) x-ray images were recorded at various selected times after the bullets passed near the femurs. This study was carried out at the Armed Forces Institute of Pathology under approved human subject protocols. The cavity sizes and shapes were observed for the two types of bullets and at a number of times during the expansion and collapse of the cavities. As the bullets passed through the thighs, narrow cavities behind the bullets were observed. At later times, large expanded cavities were observed that encompassed the entire mid-thigh region. The observed cavities are at variance with those which were reported previously in gelatin tissue simulants. Flash x-ray radiography is an effective technique for the observation of internal cavitation in cadaver thighs caused by high-velocity bullets. These observations suggest that gelatin is not a proven simulant for human cadaver tissue in the study of cavitation subsequent to high-velocity missile impact.

  4. Ultra-high Resolution Optics for EUV and Soft X-ray Inelastic Scattering

    Energy Technology Data Exchange (ETDEWEB)

    Voronov, Dmitry L.; Cambie, Rossana; Ahn, Minseung; Anderson, Erik H.; Chang, Chih-Hao; Gullikson, Eric M.; Heilmann, Ralf K.; Salmassi, Farhad; Schattenburg, Mark L.; Yashchuk, Valeriy V.; Padmore, Howard A.

    2009-09-16

    We describe a revolutionary new approach to high spectral resolution soft x-ray optics. Conventionally in the soft x-ray energy range, high spectral resolution is obtained by use of a relatively low line density grating operated in 1st order with small slits. This severely limits throughput. This limitation can be removed by use of a grating either in very high order, or with very high line density, if one can maintain high diffraction efficiency. We have developed a new technology for achieving both of these goals which should allow high throughput spectroscopy, at resolving powers of up to 106 at 1 keV. Such optics should provide a revolutionary advance for high resolution lifetime free spectroscopy, such as RIXS, and for pulse compression of chirped beams. We report recent developmental fabrication and characterization of a prototype grating optimized for 14.2 nm EUV light. The prototype grating with a 200 nm period of the blazed grating substrate coated with 20 Mo/Si bilayers with a period of 7.1 nm demonstrates good dispersion in the third order (effective groove density of 15,000 lines per mm) with a diffraction efficiency of more than 33percent.

  5. High Energy Laboratory Astrophysics using an X-Ray Microcalorimeter with an Electron Beam Ion Trap Project

    Data.gov (United States)

    National Aeronautics and Space Administration — "Since the summer of 2000 we have successfully deployed a high resolution x-ray microcalorimeter spectrometer, based on the spaceflight XRS instrument, at the...

  6. Generation of High-Power High-Intensity Short X-Ray Free-Electron-Laser Pulses.

    Science.gov (United States)

    Guetg, Marc W; Lutman, Alberto A; Ding, Yuantao; Maxwell, Timothy J; Decker, Franz-Josef; Bergmann, Uwe; Huang, Zhirong

    2018-01-05

    X-ray free-electron lasers combine a high pulse power, short pulse length, narrow bandwidth, and high degree of transverse coherence. Any increase in the photon pulse power, while shortening the pulse length, will further push the frontier on several key x-ray free-electron laser applications including single-molecule imaging and novel nonlinear x-ray methods. This Letter shows experimental results at the Linac Coherent Light Source raising its maximum power to more than 300% of the current limit while reducing the photon pulse length to 10 fs. This was achieved by minimizing residual transverse-longitudinal centroid beam offsets and beam yaw and by correcting the dispersion when operating over 6 kA peak current with a longitudinally shaped beam.

  7. Use of High-Speed X ray and Video to Analyze Distal Radius Fracture Pathomechanics.

    Science.gov (United States)

    Gutowski, Christina; Darvish, Kurosh; Liss, Frederic E; Ilyas, Asif M; Jones, Christopher M

    2015-10-01

    The purpose of this study is to investigate the failure sequence of the distal radius during a simulated fall onto an outstretched hand using cadaver forearms and high-speed X ray and video systems. This apparatus records the beginning and propagation of bony failure, ultimately resulting in distal radius or forearm fracture. The effects of 3 different wrist guard designs are investigated using this system. Serving as a proof-of-concept analysis, this study supports this imaging technique to be used in larger studies of orthopedic trauma and protective devices and specifically for distal radius fractures. Copyright © 2015 Elsevier Inc. All rights reserved.

  8. In situ X-ray ptychography imaging of high-temperature CO2 acceptor particle agglomerates

    DEFF Research Database (Denmark)

    Høydalsvik, Kristin; Fløystad, Jostein Bø; Zhao, Tiejun

    2014-01-01

    Imaging nanoparticles under relevant reaction conditions of high temperature and gas pressure is difficult because conventional imaging techniques, like transmission electron microscopy, cannot be used. Here we demonstrate that the coherent diffractive imaging technique of X-ray ptychography can...... be used for in situ phase contrast imaging in structure studies at atmospheric pressure and elevated temperatures. Lithium zirconate, a candidate CO2 capture material, was studied at a pressure of one atmosphere in air and in CO2, at temperatures exceeding 600 °C. Images with a spatial resolution better...

  9. Combinatorial Screening of Advanced Scintillators for High Resolution X-ray Detectors

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, Shifan; Tao, Dejie; Lynch, Michael; Yuan, Xianglong; Li, Yiqun

    2008-05-12

    The lack of efficient scintillators is a major problem for developing powerful x-ray detectors that are widely used in homeland security, industrial and scientific research. Intematix has developed and applied a high throughput screening process and corresponding crystal growth technology to significantly speed up the discovery process for new efficient scintillators. As a result, Intematix has invented and fabricated three new scintillators both in powder and bulk forms, which possess promising properties such as better radiation hardness and better matching for silicon diode.

  10. DEM L241, A SUPERNOVA REMNANT CONTAINING A HIGH-MASS X-RAY BINARY

    Energy Technology Data Exchange (ETDEWEB)

    Seward, F. D. [Smithsonian Astrophysical Observatory, 60 Garden Street, Cambridge, MA 02138 (United States); Charles, P. A. [School of Physics and Astronomy, University of Southampton, Highfield, Southampton SO17 1BJ (United Kingdom); Foster, D. L. [South African Astronomical Observatory, P.O. Box 9, Observatory 7935, Cape Town (South Africa); Dickel, J. R.; Romero, P. S. [Department of Physics and Astronomy, University of New Mexico, 1919 Lomas Boulevard NE, Albuquerque, NM 87131 (United States); Edwards, Z. I.; Perry, M.; Williams, R. M. [Department of Earth and Space Sciences, Columbus State University, Coca Cola Space Science Center, 701 Front Avenue, Columbus, GA 31901 (United States)

    2012-11-10

    A Chandra observation of the Large Magellanic Cloud supernova remnant DEM L241 reveals an interior unresolved source which is probably an accretion-powered binary. The optical counterpart is an O5III(f) star making this a high-mass X-ray binary with an orbital period likely to be of the order of tens of days. Emission from the remnant interior is thermal and spectral information is used to derive density and mass of the hot material. Elongation of the remnant is unusual and possible causes of this are discussed. The precursor star probably had mass >25 M {sub Sun}.

  11. Efficient multi-keV X-ray generation from high-contrast laser plasma interaction

    Directory of Open Access Journals (Sweden)

    Zhang Z.

    2013-11-01

    Full Text Available Kα line emission from Mo was experimentally and theoretically studied using clean, ultrahigh-intensity femtosecond laser pulses. The absolute yields of Kα x-rays at 17 keV from Mo were measured as a function of the laser pulse contrast ratio and irradiation intensity. Significantly enhanced Kα yields were obtained by employing high contrast ratio at optimum irradiance. Conversion efficiencies of 4.28 × 10−5/sr, the highest values obtained to date, was demonstrated with contrast ratios in the range of 10−10 to 10−11.

  12. High Pressure X-ray Diffraction Study on Icosahedral Boron Arsenide (B12As2)

    Energy Technology Data Exchange (ETDEWEB)

    J Wu; H Zhu; D Hou; C Ji; C Whiteley; J Edgar; Y Ma

    2011-12-31

    The high pressure properties of icosahedral boron arsenide (B12As2) were studied by in situ X-ray diffraction measurements at pressures up to 25.5 GPa at room temperature. B12As2 retains its rhombohedral structure; no phase transition was observed in the pressure range. The bulk modulus was determined to be 216 GPa with the pressure derivative 2.2. Anisotropy was observed in the compressibility of B12As2-c-axis was 16.2% more compressible than a-axis. The boron icosahedron plays a dominant role in the compressibility of boron-rich compounds.

  13. The supersoft X-ray source in V5116 Sagittarii. I. The high resolution spectra

    Science.gov (United States)

    Sala, G.; Ness, J. U.; Hernanz, M.; Greiner, J.

    2017-05-01

    Context. Classical nova explosions occur on the surface of an accreting white dwarf in a binary system. After ejection of a fraction of the envelope and when the expanding shell becomes optically thin to X-rays, a bright source of supersoft X-rays arises, powered by residual H burning on the surface of the white dwarf. While the general picture of the nova event is well established, the details and balance of accretion and ejection processes in classical novae are still full of unknowns. The long-term balance of accreted matter is of special interest for massive accreting white dwarfs, which may be promising supernova Ia progenitor candidates. Nova V5116 Sgr 2005b was observed as a bright and variable supersoft X-ray source by XMM-Newton in March 2007, 610 days after outburst. The light curve showed a periodicity consistent with the orbital period. During one third of the orbit the luminosity was a factor of seven brighter than during the other two thirds of the orbital period. Aims: In the present work we aim to disentangle the X-ray spectral components of V5116 Sgr and their variability. Methods: We present the high resolution spectra obtained with XMM-Newton RGS and Chandra LETGS/HRC-S in March and August 2007. Results: The grating spectrum during the periods of high-flux shows a typical hot white dwarf atmosphere dominated by absorption lines of N VI and N VII. During the low-flux periods, the spectrum is dominated by an atmosphere with the same temperature as during the high-flux period, but with several emission features superimposed. Some of the emission lines are well modeled with an optically thin plasma in collisional equilibrium, rich in C and N, which also explains some excess in the spectra of the high-flux period. No velocity shifts are observed in the absorption lines, with an upper limit set by the spectral resolution of 500 km s-1, consistent with the expectation of a non-expanding atmosphere so late in the evolution of the post-nova. Based on

  14. High spectral resolution x-ray optics with highly oriented pyrolytic graphite.

    Science.gov (United States)

    Legall, H; Stiel, H; Arkadiev, V; Bjeoumikhov, A A

    2006-05-15

    Thin films of highly oriented pyrolytic graphite (HOPG) give the opportunity to realize crystal optics with arbitrary geometry by mounting it on a mould of any shape. A specific feature of HOPG is its mosaicity accompanied by a high integral reflectivity, which is by an order of magnitude higher than that of all other known crystals in an energy range between 2 keV up to several 10 keV. These characteristics make it possible to realize highly efficient collecting optics, which could be also relevant for compact x-ray diagnostic tools and spectrometers. For these applications the achievable spectral resolution of the crystal optics is of interest. In this article measurements with a spectral resolution of E/DeltaE=2900 in the second order reflection and E/DeltaE=1800 in the first order reflection obtained with HOPG crystals are presented. These are by far the highest spectral resolutions reported for HOPG crystals. The integral reflectivity of these very thin films is still comparable with that of ideal Ge crystals. The trade-off between energy resolution and high integral reflectivity for HOPG is demonstrated by determining these parameters for HOPG films of different thickness.

  15. Hard X-ray polarimetry with Caliste, a high performance CdTe based imaging spectrometer

    Science.gov (United States)

    Antier, S.; Ferrando, P.; Limousin, O.; Caroli, E.; Curado da Silva, R. M.; Blondel, C.; Chipaux, R.; Honkimaki, V.; Horeau, B.; Laurent, P.; Maia, J. M.; Meuris, A.; Del Sordo, S.; Stephen, J. B.

    2015-06-01

    Since the initial exploration of the X- and soft γ-ray sky in the 60's, high-energy celestial sources have been mainly characterized through imaging, spectroscopy and timing analysis. Despite tremendous progress in the field, the radiation mechanisms at work in sources such as neutrons stars, black holes, and Active Galactic Nuclei are still unclear. The polarization state of the radiation is an observational parameter which brings key additional information about the physical processes in these high energy sources, allowing the discrimination between competing models which may otherwise all be consistent with other types of measurement. This is why most of the projects for the next generation of space missions covering the few tens of keV to the MeV region require a polarization measurement capability. A key element enabling this capability, in this energy range, is a detector system allowing the identification and characterization of Compton interactions as they are the main process at play. The compact hard X-ray imaging spectrometer module, developed in CEA with the generic name of "Caliste" module, is such a detector. In this paper, we present experimental results for two types of Caliste-256 modules, one based on a CdTe crystal, the other one on a CdZnTe crystal, which have been exposed to linearly polarized beams at the European Synchrotron Radiation Facility (ESRF). These results, obtained at 200 and 300 keV, demonstrate the capability of these modules to detect Compton events and to give an accurate determination of the polarization parameters (polarization angle and fraction) of the incoming beam. For example, applying an optimized selection to our data set, equivalent to select 90° Compton scattered interactions in the detector plane, we find a modulation factor Q of 0.78 ± 0.06 in the 200-300 keV range. The polarization angle and fraction are derived with accuracies of approximately 1° and 5 % respectively for both CdZnTe and CdTe crystals. The

  16. X-ray imaging

    Energy Technology Data Exchange (ETDEWEB)

    Fenster, A. [Univ. of Western Ontario, J.P. Robarts Institute, London, Ontario (Canada); Yaffe, M.J. [Univ. of Toronto, Depts. of Medical Biophysics and Medical Imaging, North York, Ontario (Canada)

    1995-09-01

    In this article, we briefly review the principles of x-ray imaging, consider some of its applications in medicine and describe some of the developments in this area which have taken place in Canada. X rays were first used for diagnosis and therapy in medicine almost immediately after the report of their discovery by Roentgen in 1895. X-ray imaging has remained the primary tool for the investigation of structures within the body up to the present time (Johns and Cunningham 1983). Medical x rays are produced in a vacuum tube by the electron bombardment of a metallic target. Electrons emitted from a heated cathode are accelerated through an electric field to energies of 20-150 keV (wavelength 6.2-0.83 nm) and strike a target anode. X rays appear in a spectrum of bremsstrahlung radiation with energies ranging from 0 to a value that is numerically equal to the peak voltage applied between the cathode and anode of the x-ray tube (Figure 1). In addition, where the energy of the impinging electrons exceeds the binding energy of inner atomic orbitals of the target material, electrons may be ejected from those shells. Filling of these shells by more loosely-bound electrons gives rise to x rays whose energies are equal to the difference of the binding energies of the donor and acceptor shells. The energies of these characteristic x rays are unique to the target material. Less than 1% of the energy of the incident electrons is converted to that of x rays, while the remainder is dissipated as heat in the target. For this reason, a tremendous amount of engineering has gone into the design of x-ray tubes that can yield a large fluence rate of quanta from a small effective source size, while withstanding the enormous applied heat loading (e.g. 10 kJ per exposure). Tungsten is by far the most common material used for targets in tubes for diagnostic radiology, because of its high melting point and its high atomic number; the efficiency of x-ray production is proportional to Z of the

  17. Novel ultra-lightweight and high-resolution MEMS x-ray optics

    Science.gov (United States)

    Mitsuishi, Ikuyuki; Ezoe, Yuichiro; Takagi, Utako; Mita, Makoto; Riveros, Raul; Yamaguchi, Hitomi; Kato, Fumiki; Sugiyama, Susumu; Fujiwara, Kouzou; Morishita, Kohei; Nakajima, Kazuo; Fujihira, Shinya; Kanamori, Yoshiaki; Yamasaki, Noriko Y.; Mitsuda, Kazuhisa; Maeda, Ryutaro

    2009-05-01

    We have been developing ultra light-weight X-ray optics using MEMS (Micro Electro Mechanical Systems) technologies.We utilized crystal planes after anisotropic wet etching of silicon (110) wafers as X-ray mirrors and succeeded in X-ray reflection and imaging. Since we can etch tiny pores in thin wafers, this type of optics can be the lightest X-ray telescope. However, because the crystal planes are alinged in certain directions, we must approximate ideal optical surfaces with flat planes, which limits angular resolution of the optics on the order of arcmin. In order to overcome this issue, we propose novel X-ray optics based on a combination of five recently developed MEMS technologies, namely silicon dry etching, X-ray LIGA, silicon hydrogen anneal, magnetic fluid assisted polishing and hot plastic deformation of silicon. In this paper, we describe this new method and report on our development of X-ray mirrors fabricated by these technologies and X-ray reflection experiments of two types of MEMS X-ray mirrors made of silicon and nickel. For the first time, X-ray reflections on these mirrors were detected in the angular response measurements. Compared to model calculations, surface roughness of the silicon and nickel mirrors were estimated to be 5 nm and 3 nm, respectively.

  18. A method for high-energy, low-dose mammography using edge illumination x-ray phase-contrast imaging

    Science.gov (United States)

    Diemoz, Paul C.; Bravin, Alberto; Sztrókay-Gaul, Anikó; Ruat, Marie; Grandl, Susanne; Mayr, Doris; Auweter, Sigrid; Mittone, Alberto; Brun, Emmanuel; Ponchut, Cyril; Reiser, Maximilian F.; Coan, Paola; Olivo, Alessandro

    2016-12-01

    Since the breast is one of the most radiosensitive organs, mammography is arguably the area where lowering radiation dose is of the uttermost importance. Phase-based x-ray imaging methods can provide opportunities in this sense, since they do not require x-rays to be stopped in tissue for image contrast to be generated. Therefore, x-ray energy can be considerably increased compared to those usually exploited by conventional mammography. In this article we show how a novel, optimized approach can lead to considerable dose reductions. This was achieved by matching the edge-illumination phase method, which reaches very high angular sensitivity also at high x-ray energies, to an appropriate image processing algorithm and to a virtually noise-free detection technology capable of reaching almost 100% efficiency at the same energies. Importantly, while proof-of-concept was obtained at a synchrotron, the method has potential for a translation to conventional sources.

  19. R&D Toward a Compact High-Brilliance X-Ray Source Based on Channeling Radiation

    Energy Technology Data Exchange (ETDEWEB)

    Piot, P.; /Fermilab /Northern Illinois U.; Brau, C.A.; Choi, B.K.; Gabella, W.E.; Jarvis, J.D.; Mendenhall, M.H.; /Vanderbilt U.; Lewellen, J.W.; /Naval Postgraduate School; Mihalcea, D.; /Northern Illinois U.

    2012-08-01

    X-rays have been valuable to a large number of fields including Science, Medicine, and Security. Yet, the availability of a compact high-spectral brilliance X-ray sources is limited. A technique to produce X-rays with spectral brilliance B {approx} 10{sup 12} photons.(mm-mrd){sup -2}.(0.1% BW){sup -1} .s{sup -1} is discussed. The method is based on the generation and acceleration of a low-emittance field-emitted electron bunches. The bunches are then focused on a diamond crystal thereby producing channeling radiation. In this paper, after presenting the overarching concept, we discuss the generation, acceleration and transport of the low-emittance bunches with parameters consistent with the production of high-brilliance X-rays through channeling radiation. We especially consider the example of the Advanced Superconducting Test Accelerator (ASTA) currently in construction at Fermilab where a proof-of-principle experiment is in preparation.

  20. A high-resolution x-ray spectrometer for a kaon mass measurement

    Science.gov (United States)

    Phelan, Kevin; Suzuki, Ken; Zmeskal, Johann; Tortorella, Daniele; Bühler, Matthias; Hertrich, Theo

    2017-02-01

    The ASPECT consortium (Adaptable Spectrometer Enabled by Cryogenic Technology) is currently constructing a generalised cryogenic platform for cryogenic detector work which will be able to accommodate a wide range of sensors. The cryogenics system is based on a small mechanical cooler with a further adiabatic demagnetisation stage and will work with cryogenic detectors at sub-Kelvin temperatures. The commercial aim of the consortium is to produce a compact, user-friendly device with an emphasis on reliability and portability which can easily be transported for specialised on-site work, such as beam-lines or telescope facilities. The cryogenic detector platform will accommodate a specially developed cryogenic sensor, either a metallic magnetic calorimeter or a magnetic penetration-depth thermometer. The detectors will be designed to work in various temperatures regions with an emphasis on optimising the various detector resolutions for specific temperatures. One resolution target is of about 10 eV at the energies range typically created in kaonic atoms experiments (soft x-ray energies). A following step will see the introduction of continuous, high-power, sub-Kelvin cooling which will bring the cryogenic basis for a high resolution spectrometer system to the market. The scientific goal of the project will produce an experimental set-up optimised for kaon-mass measurements performing high-resolution x-ray spectroscopy on a beam-line provided foreseeably by the J-PARC (Tokai, Japan) or DAΦNE (Frascati, Italy) facilities.

  1. High resolution X-ray detector for synchrotron-based microtomography

    CERN Document Server

    Stampanoni, M; Wyss, P; Abela, R; Patterson, B; Hunt, S; Vermeulen, D; Rueegsegger, P

    2002-01-01

    Synchrotron-based microtomographic devices are powerful, non-destructive, high-resolution research tools. Highly brilliant and coherent X-rays extend the traditional absorption imaging techniques and enable edge-enhanced and phase-sensitive measurements. At the Materials Science Beamline MS of the Swiss Light Source (SLS), the X-ray microtomographic device is now operative. A high performance detector based on a scintillating screen optically coupled to a CCD camera has been developed and tested. Different configurations are available, covering a field of view ranging from 715x715 mu m sup 2 to 7.15x7.15 mm sup 2 with magnifications from 4x to 40x. With the highest magnification 480 lp/mm had been achieved at 10% modulation transfer function which corresponds to a spatial resolution of 1.04 mu m. A low-noise fast-readout CCD camera transfers 2048x2048 pixels within 100-250 ms at a dynamic range of 12-14 bit to the file server. A user-friendly graphical interface gives access to the main parameters needed for ...

  2. High-energy x-ray Talbot-Lau radiography of a human knee

    Science.gov (United States)

    Horn, F.; Gelse, K.; Jabari, S.; Hauke, C.; Kaeppler, S.; Ludwig, V.; Meyer, P.; Michel, T.; Mohr, J.; Pelzer, G.; Rieger, J.; Riess, C.; Seifert, M.; Anton, G.

    2017-08-01

    We report on a radiographic measurement of an ex vivo human knee using a grating-based phase-contrast imaging setup and a medical x-ray tube at a tube voltage of 70 kV. The measurement has been carried out using a Talbot-Lau setup that is suitable to achieve a high visibility in the energy regime of medical imaging. In a medical reading by an experienced trauma surgeon signatures of chondrocalcinosis in the medial meniscus have been identified more evidently using the dark-field image in comparison to the conventional attenuation image. The analysis has been carried out at various dose levels down to 0.14 mGy measured as air kerma, which is a dose comparable to clinically used radiographic devices. The diagnosis has been confirmed by a histological analysis of the meniscus tissue. In the introduced high-frequency filtered phase-contrast image the anterior and posterior horn of the medial meniscus and the posterior cruciate ligament have also been visible. Furthermore, atherosclerotic plaque is visible in both imaging modalities, attenuation and dark-field, despite the presence of overlaying bone. This measurement, for the first time, proves the feasibility of Talbot-Lau x-ray imaging at high-energy spectra above 40 kVp and reasonable dose levels with regard to spacious and dense objects.

  3. Near-Infrared Follow-up of High Redshift X-ray Clusters

    Science.gov (United States)

    Barkhouse, Wayne; Green, Paul; Vikhlinin, Alexey; Kim, Dong-Woo

    2005-08-01

    Clusters of galaxies provide an intimate view of galaxy evolution over a wide range in cosmic look-back time and environment. From a large Chandra/NOAO serendipitous survey, we have culled a high- confidence list of high redshift cluster candidates to facilitate the investigation of galaxy cluster evolution and provide strong constraints on cosmological parameters. We propose to use FLAMINGOS on the KPNO 4-m telescope to obtain deep near-IR imaging in the J- and K_s-band of 6 extended X-ray sources discovered serendipitously in Chandra images, but undetected in deep 4m/MOSAIC imaging. Our FLAMINGOS observations will measure cluster redshifts (out to z~ 1.5) using the location of the cluster red-sequence in the color-magnitude plane. Cluster attributes, such as the luminosity function, richness, color-magnitude relation, and correlations between near-IR and X-ray properties, will be measured and contrasted with our more local serendipitous sample. These observations promise to substantially increase the number of known high redshift galaxy clusters.

  4. Unsteady void measurements within debris beds using high speed X-ray tomography

    Energy Technology Data Exchange (ETDEWEB)

    Laurien, E., E-mail: Laurien@ike.uni-stuttgart.de; Stürzel, T., E-mail: thilo.stuerzel@stihl.de; Zhou, M., E-mail: mi.zhou@ike.uni-stuttgart.de

    2017-02-15

    Highlights: • A high speed X-ray tomography facility has been built for the investigation on two-phase flow. • The two-phase flow through beds of packed plastic spheres has been investigated in the facility. • 3D-reconstructions from the measurements show the fluxes in the two-phase flow. • The gas fraction has been calculated from the reconstruction and used for validation of the modeling. • A new bed with closest regular spheres arrangement has been manufactured by 3D-plotter and used in the measurement. - Abstract: Two-phase flow and boiling within debris beds representing a destroyed reactor core after a severe accident with core fragmentation can be simulated by using the porous media approach. In this approach, a local pressure drop and the heat transfer between the solid debris particles and the two-phase flow is modelled with the help flow-pattern maps, in which the boundaries between bubbly, slug, and annular flow are assumed. In order to support further understanding of these flows we have developed a very fast X-ray measurement device to visualize the 3D-void distribution within particle beds or porous media, which are otherwise un-accessible internally. The experimental setup uses a scanned electron beam directed in circles on a tungsten target to generate the X-rays. The particle bed, which has a diameter of 70 mm, is located between this target and a field of 256 X-ray detectors, which are arranged on a circle concentric to the target. The void distribution is reconstructed numerically from the attenuation of signals, which penetrates the particle bed and the two-phase flow inside. A 3D frame rate of up to 1000 Hz can be reached. The spatial resolution is such that bubbles with a diameter > 1.7 mm can be detected. We have investigated two-phase flows air/water through beds of packed plastic spheres (diameter between 3 and 15 mm) as well as through plastic beds, which were manufactured using a ‘3D-plotter’. Flow patterns can be

  5. So Many Rockets - The Road to High Resolution Imaging in X-rays

    Science.gov (United States)

    Murray, Stephen S.

    2013-01-01

    When I first begin to work on new imaging detectors for X-ray Astronomy I was at AS&E and I worked with Leon Van Speybroeck and Ed Kellogg on a sounding rocket project. We starting by using a microchannel plate image intensifier to detect X-ray photons and convert them to flashes of light that were recorded on 35 mm film frames. Simultaneously there was a 16 mm star camera taking frames so we could tell where the X-rays were coming from. I spent about 6 years working on this payload, eventually becoming the PI and evolving the detector from a film readout to an electronic readout (the crossed grid charge detector) that was the basis for the Einstein, ROSAT and Chandra High Resolution Imagers and Cameras. We had a series of about 6 or so rocket flights culminating in the 1978 flight that actually worked. We detected three photons from Sco X1, and background data from that flight allowed us to set the detector front bias voltage to minimize non-X-ray background for the Einstein HRI. Just about everything that could go wrong on those rockets did go wrong, from a switch not closing to a rocket misfire, to pointing 180 degrees off target. But we learned something each flight and kept coming back to try again. The worse thing for me was having to stay up all night at White Sands in a small darkroom where I could avoid the night crawlers and scorpions that frightened me to death. Not to mention the daredevil helicopter pilots who flew us to the recovery site hugging the ground at top speed all the way there! None-the-less, in the end we succeeded in our goals, and there is nothing so exciting as watching your payload being launched at night (even it did mean sneaking out from the bunker to do it!). Thanks to NASA and the US Navy's White Sands USS Desert Ship (LLS-1; Land Locked Ship - 1) for all the support.

  6. Generation of hard X-ray from solid target irradiated by UV high intensity ultrashort pulse laser

    CERN Document Server

    Tao Ye; Tang Xiu Zhang; Shan Yu Sheng; Wang Nai Yan

    2002-01-01

    Hard X-ray continuum generated from interaction of UV high intensity ultrashort pulse laser with solid target has been investigated by experiment. P-polarized light irradiating 5 mm Cu slab with 45 degree, the hard X-ray with energy of 200 keV has been detected. Fitting the experiment data by Maxwellian distribution, the temperature of hot electron is 67 keV. The experiment data are the results of combination of several absorption mechanisms

  7. High-resolution soft X-ray beamline ADRESS at the Swiss Light Source for resonant inelastic X-ray scattering and angle-resolved photoelectron spectroscopies

    Science.gov (United States)

    Strocov, V. N.; Schmitt, T.; Flechsig, U.; Schmidt, T.; Imhof, A.; Chen, Q.; Raabe, J.; Betemps, R.; Zimoch, D.; Krempasky, J.; Wang, X.; Grioni, M.; Piazzalunga, A.; Patthey, L.

    2010-01-01

    The concepts and technical realisation of the high-resolution soft X-ray beamline ADRESS operating in the energy range from 300 to 1600 eV and intended for resonant inelastic X-ray scattering (RIXS) and angle-resolved photoelectron spectroscopy (ARPES) are described. The photon source is an undulator of novel fixed-gap design where longitudinal movement of permanent magnetic arrays controls not only the light polarization (including circular and 0–180° rotatable linear polarizations) but also the energy without changing the gap. The beamline optics is based on the well established scheme of plane-grating monochromator operating in collimated light. The ultimate resolving power E/ΔE is above 33000 at 1 keV photon energy. The choice of blazed versus lamellar gratings and optimization of their profile parameters is described. Owing to glancing angles on the mirrors as well as optimized groove densities and profiles of the gratings, the beamline is capable of delivering high photon flux up to 1 × 1013 photons s−1 (0.01% BW)−1 at 1 keV. Ellipsoidal refocusing optics used for the RIXS endstation demagnifies the vertical spot size down to 4 µm, which allows slitless operation and thus maximal transmission of the high-resolution RIXS spectrometer delivering E/ΔE > 11000 at 1 keV photon energy. Apart from the beamline optics, an overview of the control system is given, the diagnostics and software tools are described, and strategies used for the optical alignment are discussed. An introduction to the concepts and instrumental realisation of the ARPES and RIXS endstations is given. PMID:20724785

  8. High-resolution x-ray scattering studies of charge ordering in highly correlated electron systems

    CERN Document Server

    Ghazi, M E

    2002-01-01

    addition, another very weak satellites with wavevector (1/2, 1, 1/2) were observed possibly due to spin ordering. two-dimensional in nature both by measurements of their correlation lengths and by measurement of the critical exponents of the charge stripe melting transition with an anomaly at x = 0.25. The results show by decreasing the hole concentration from the x = 0.33 to 0.2, the well-correlated charge stripes change to a glassy state at x = 0.25. The electronic transition into the charge stripe phase is second-order without any corresponding structural transition. Above the second-order transition critical scattering was observed due to fluctuations into the charge stripe phase. In a single-crystal of Nd sub 1 sub / sub 2 Sr sub 1 sub / sub 2 MnO sub 3 a series of phase transitions were observed using high-resolution synchrotron X-ray scattering. Above the charge ordering transition temperature, T sub C sub O , by measuring the peak profiles of Bragg reflections as a function of temperature, it was foun...

  9. Preparation of clay mineral samples for high resolution x-ray imaging

    Science.gov (United States)

    Abbati, Gennaro; Seim, Christian; Legall, Herbert; Stiel, Holger; Thomas, Noel; Wilhein, Thomas

    2013-10-01

    In the development of optimum ceramic materials for plastic forming, it is of fundamental importance to gain insight into the compositions of the clay minerals. Whereas spectroscopic methods are adequate for determining the elemental composition of a given sample, a knowledge of the spatial composition, together with the shape and size of the particles leads to further, valuable insight. This requires an imaging technique such as high resolution X-ray microscopy. In addition, fluorescence spectroscopy provides a viable element mapping technique. Since the fine particle fraction of the materials has a major effect on physical properties like plasticity, the analysis is focused mainly on the smallest particles. To separate these from the bigger agglomerates, the raw material has to pass through several procedures like centrifugation and filtering. After that, one has to deposit a layer of appropriate thickness on to a suitable substrate. These preparative techniques are described here, starting from the clay mineral raw materials and proceeding through to samples that are ready to analyze. First results using high resolution x-ray imaging are shown.

  10. Metrology of Epitaxial Thin Films and Periodic Nanostructures using High Resolution X-Ray Diffraction Techniques

    Science.gov (United States)

    Medikonda, Manasa

    The continued scaling of device size to achieve higher performance and/or lower power operation at lower cost is driving research and development into new, 3D transistor structures such as the FinFET. This research and development effort is highlighting the need for new, advanced measurement capability that is highly accurate, reliable, rapid, and nondestructive. Periodic arrays of fin structures enable process monitoring at each level of fabrication and the maintenance of overall device yield. High resolution x-ray diffraction (HR XRD) has been shown to provide unique capability of characterizing blanket thin films and structural parameters of periodic arrays of fins fabricated in single crystal materials. Application of HR XRD techniques to characterize fin structures with critical dimensions of 1x-2x nm has been very limited. The main objective of my research is to develop and apply HR XRD techniques that analyze critical parameters such as the lithographic pitch, pitch walking, sidewall slope, and fin top width in arrays of advanced fin structures. This research also investigates the stress state of initially pseudomorphic epilayers at the top of the fin, and identification of defects. The results for non-patterned epitaxial fully strained SiGe and GeSn alloys are presented and the methods of detecting periodicity, strain state and shape of arrays of lithographically patterned silicon and silicon-germanium fins are demonstrated using synchrotron source and laboratory x-ray diffractometers.

  11. High energy white beam x-ray diffraction studies of residual strains in engineering components

    Science.gov (United States)

    Zhang, S. Y.; Vorster, W.; Jun, T. S.; Song, X.; Golshan, M.; Laundy, D.; Walsh, M. J.; Korsunsky, A. M.

    2008-09-01

    In order to predict the durability of engineering components and improve performance, it is mandatory to understand residual stresses. The last decade has witnessed a significant increase of residual stress evaluation using diffraction of penetrating radiation, such as neutrons or high energy X-rays. They provide a powerful non-destructive method for determining the level of residual stresses in engineering components through precise characterisation of interplanar crystal lattice spacing. The unique non-destructive nature of these measurement techniques is particularly beneficial in the context of engineering design, since it allows the evaluation of a variety of structural and deformational parameters inside real components without material removal, or at worst with minimal interference. However, while most real engineering components have complex shape and are often large in size, leading to measurement and interpretation difficulties, since experimental facilities usually have limited space for mounting the sample, limited sample travel range, limited loading capacity of the sample positioning system, etc. Consequently, samples often have to be sectioned, requiring appropriate corrections on measured data; or facilities must be improved. Our research group has contributed to the development of engineering applications of high-energy X-ray diffraction methods for residual stress evaluation, both at synchrotron sources and in the lab setting, including multiple detector setup, large engineering component manipulation and measurement at the UK Synchrotron Radiation Source (SRS Daresbury), and in our lab at Oxford. A nickel base superalloy combustion casing and a large MIG welded Al alloy plate were successfully studied.

  12. HERO: High Energy Replicated Optics for a Hard-X-Ray Balloon Payload

    Science.gov (United States)

    Ramsey, B.; Engelhaupt, D.; Speegle, C. O.; ODell, S. L.; Austin, R. A.; Elsner, R. F.; Kolodziejczak, J. J.; Weisskopf, M. C.

    2000-01-01

    We are developing high-energy grazing-incidence replicated optics for a balloon-borne hard-x-ray telescope. When completed, the instrument will have 170 cm2 of effective collecting area at 40 keV and 130 square cm at 60 keV with <= 30 arc seconds half power diameter. This payload will offer unprecedented sensitivity in the hard-x-ray region, with around 250 microCrab sensitivity on long-duration flights and 50-100 microCrab on ultra- long-duration balloon missions The payload consists of 16 mirror modules, each with 14 nested mirrors made from a high-strength nickel alloy, and a corresponding array of 16 focal plane detectors. An engineering demonstration flight is scheduled for the Spring of 2000, using just two mirror modules each with 3 shells, above a pair of gas-scintillation-proportional counters. This flight is intended to test a newly designed gondola pointing and aspect system and the stability of the optical bench design. The first scientific flight of the full payload is scheduled for the Fall of 2002. Full details of the payload and its capabilities will be presented together with data from various mirror-module tests. If available data from the first flight will also be presented.

  13. Characterization of High-k Nanolayers by Grazing Incidence X-ray Spectrometry

    Directory of Open Access Journals (Sweden)

    Matthias Müller

    2014-04-01

    Full Text Available The accurate characterization of nanolayered systems is an essential topic for today’s developments in many fields of material research. Thin high-k layers and gate stacks are technologically required for the design of current and future electronic devices and can be deposited, e.g., by Atomic Layer Deposition (ALD. However, the metrological challenges to characterize such systems demand further development of analytical techniques. Reference-free Grazing Incidence X-ray Fluorescence (GIXRF based on synchrotron radiation can significantly contribute to the characterization of such nanolayered systems. GIXRF takes advantage of the incident angle dependence of XRF, in particular below the substrate’s critical angle where changes in the X-ray Standing Wave field (XSW intensity influence the angular intensity profile. The reliable modeling of the XSW in conjunction with the radiometrically calibrated instrumentation at the PTB allows for reference-free, fundamental parameter-based quantitative analysis. This approach is very well suited for the characterization of nanoscaled materials, especially when no reference samples with sufficient quality are available. The capabilities of this method are demonstrated by means of two systems for transistor gate stacks, i.e., Al2O3 high-k layers grown on Si or Si/SiO2 and Sc2O3 layers on InGaAs/InP substrates.

  14. Two-dimensional position-sensitive gaseous detectors for high-resolution neutron and X-ray diffraction

    CERN Document Server

    Marmotti, M; Kampmann, R

    2002-01-01

    Two-dimensional position-sensitive gaseous detectors have been developed at the Geesthacht Neutron Facility (GeNF) for high-resolution neutron and X-ray diffractometry. They are multi-wire proportional counters with delay-line readout and sensitive areas of 300 mm x 300 mm or 500 mm x 500 mm. For detecting X-rays, neutrons and hard X-rays the counters are filled with Ar/CO sub 2 , sup 3 He/CF sub 4 and Xe/CO sub 2 , respectively. One neutron detector is used at the ARES diffractometer at GKSS, which is dedicated to the analysis of residual stresses. Further ones are used for analysing textures and residual stresses at the hard-X-ray beamline PETRA-2 at HASYLAB, and one detector is being developed for the neutron reflectometer REFSANS at the research reactor FRM-II in Munich, Germany. (orig.)

  15. Design and performance of a soft-x-ray interferometer for ultra-high-resolution fourier transform spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Moler, E.J.; Hussain, Z.; Duarte, R.M.; Howells, M.R. [Lawrence Berkeley National Lab., CA (United States)

    1997-04-01

    A Fourier Transform Soft X-ray spectrometer (FT-SX) has been designed and is under construction for the Advanced Light Source (ALS) at Lawrence Berkeley National Laboratory as a branch of beamline 9.3.2. The spectrometer is a novel soft x-ray interferometer designed for ultra-high resolution (theoretical resolving power E/{delta}E{approximately}10{sup 6}) spectroscopy in the photon energy region of 60-120 eV. This instrument is expected to provide experimental results which sensitively test models of correlated electron processes in atomic and molecular physics. The design criteria and consequent technical challenges posed by the short wavelengths of x-rays and desired resolving power are discussed. The fundamental and practical aspects of soft x-ray interferometry are also explored.

  16. Accuracy validation of incident photon fluence on DQE for various measurement conditions and X-ray units.

    Science.gov (United States)

    Haba, Tomonobu; Kondo, Shimpei; Hayashi, Daiki; Koyama, Shuji

    2013-07-01

    Detective quantum efficiency (DQE) is widely used as a comprehensive metric for X-ray image evaluation in digital X-ray units. The incident photon fluence per air kerma (SNR²(in)) is necessary for calculating the DQE. The International Electrotechnical Commission (IEC) reports the SNR²(in) under conditions of standard radiation quality, but this SNR²(in) might not be accurate as calculated from the X-ray spectra emitted by an actual X-ray tube. In this study, we evaluated the error range of the SNR²(in) presented by the IEC62220-1 report. We measured the X-ray spectra emitted by an X-ray tube under conditions of standard radiation quality of RQA5. The spectral photon fluence at each energy bin was multiplied by the photon energy and the mass energy absorption coefficient of air; then the air kerma spectrum was derived. The air kerma spectrum was integrated over the whole photon energy range to yield the total air kerma. The total photon number was then divided by the total air kerma. This value is the SNR²(in). These calculations were performed for various measurement parameters and X-ray units. The percent difference between the calculated value and the standard value of RQA5 was up to 2.9%. The error range was not negligibly small. Therefore, it is better to use the new SNR²(in) of 30694 (1/(mm(2) μGy)) than the current [Formula: see text] of 30174 (1/(mm(2) μGy)).

  17. Thin fused silica shells for high-resolution and large collecting area x-ray telescopes (like Lynx/XRS)

    Science.gov (United States)

    Civitani, M. M.; Hołyszko, J.; Vecchi, G.; Basso, S.; Citterio, O.; Ghigo, M.; Pareschi, G.; Parodi, G.; Incorvaia, S.

    2017-09-01

    The implementation of an X-ray mission with high imaging capabilities, similar to those achieved with Chandra (technological task of the mirror fabrication, different approaches are considered, based on monolithic and segmented shells. Starting from the experience done on the glass prototypal shell realized in the past years, the direct polishing of thin (2 mm thick) fused silica monolithic shells is being investigated as a possible solution. A temporary stiffening structure is designed to support the shell during the figuring and polishing operations and to manage the handling up to its integration in the telescope structure. After the grinding and the polishing phases, in order to achieve the required surface accuracy, a final ion beam figuring correction is foreseen. In this paper, we present the technological process and the results achieved so far on a prototypal shell under development.

  18. Development of a high resolution x-ray spectrometer for the National Ignition Facility (NIF).

    Science.gov (United States)

    Hill, K W; Bitter, M; Delgado-Aparicio, L; Efthimion, P C; Ellis, R; Gao, L; Maddox, J; Pablant, N A; Schneider, M B; Chen, H; Ayers, S; Kauffman, R L; MacPhee, A G; Beiersdorfer, P; Bettencourt, R; Ma, T; Nora, R C; Scott, H A; Thorn, D B; Kilkenny, J D; Nelson, D; Shoup, M; Maron, Y

    2016-11-01

    A high resolution (E/ΔE = 1200-1800) Bragg crystal x-ray spectrometer is being developed to measure plasma parameters in National Ignition Facility experiments. The instrument will be a diagnostic instrument manipulator positioned cassette designed mainly to infer electron density in compressed capsules from Stark broadening of the helium-β (1s 2 -1s3p) lines of krypton and electron temperature from the relative intensities of dielectronic satellites. Two conically shaped crystals will diffract and focus (1) the Kr Heβ complex and (2) the Heα (1s 2 -1s2p) and Lyα (1s-2p) complexes onto a streak camera photocathode for time resolved measurement, and a third cylindrical or conical crystal will focus the full Heα to Heβ spectral range onto an image plate to provide a time integrated calibration spectrum. Calculations of source x-ray intensity, spectrometer throughput, and spectral resolution are presented. Details of the conical-crystal focusing properties as well as the status of the instrumental design are also presented.

  19. X-ray phase-contrast tomography for high-spatial-resolution zebrafish muscle imaging

    Science.gov (United States)

    Vågberg, William; Larsson, Daniel H.; Li, Mei; Arner, Anders; Hertz, Hans M.

    2015-11-01

    Imaging of muscular structure with cellular or subcellular detail in whole-body animal models is of key importance for understanding muscular disease and assessing interventions. Classical histological methods for high-resolution imaging methods require excision, fixation and staining. Here we show that the three-dimensional muscular structure of unstained whole zebrafish can be imaged with sub-5 μm detail with X-ray phase-contrast tomography. Our method relies on a laboratory propagation-based phase-contrast system tailored for detection of low-contrast 4-6 μm subcellular myofibrils. The method is demonstrated on 20 days post fertilization zebrafish larvae and comparative histology confirms that we resolve individual myofibrils in the whole-body animal. X-ray imaging of healthy zebrafish show the expected structured muscle pattern while specimen with a dystrophin deficiency (sapje) displays an unstructured pattern, typical of Duchenne muscular dystrophy. The method opens up for whole-body imaging with sub-cellular detail also of other types of soft tissue and in different animal models.

  20. Revisit of alpha-chitin crystal structure using high resolution X-ray diffraction data.

    Science.gov (United States)

    Sikorski, Pawel; Hori, Ritsuko; Wada, Masahisa

    2009-05-11

    High resolution synchrotron X-ray fiber diffraction data recorded from crab tendon chitin have been used to describe the crystal structure of alpha-chitin. Crystal structures at 100 and 300 K have been solved using restrained crystallographic refinement against diffraction intensities measured from the fiber diffraction patterns. The unit cell contains two polymer chains in a 2(1) helix conformation and in the antiparallel orientation. The best agreement between predicated and observed X-ray diffraction intensities is obtained for a model that includes two distinctive conformations of C6-O6 hydroxymethl group. Those conformations are different from what is proposed in the generally accepted alpha-chitin crystal structure (J. Mol. Biol. 1978, 120, 167-181). Based on refined positions of the O6 atoms, a network of hydrogen bonds involving O6 is proposed. This network of hydrogen bonds can explain the main features of the polarized FTIR spectra of alpha-chitin and sheds some light on the origin of splitting of the amide I band observed on alpha-chitin IR spectra.

  1. Quantitative analysis of nanoparticle internalization in mammalian cells by high resolution X-ray microscopy

    Directory of Open Access Journals (Sweden)

    Hua Tzu-En

    2011-04-01

    Full Text Available Abstract Background Quantitative analysis of nanoparticle uptake at the cellular level is critical to nanomedicine procedures. In particular, it is required for a realistic evaluation of their effects. Unfortunately, quantitative measurements of nanoparticle uptake still pose a formidable technical challenge. We present here a method to tackle this problem and analyze the number of metal nanoparticles present in different types of cells. The method relies on high-lateral-resolution (better than 30 nm transmission x-ray microimages with both absorption contrast and phase contrast -- including two-dimensional (2D projection images and three-dimensional (3D tomographic reconstructions that directly show the nanoparticles. Results Practical tests were successfully conducted on bare and polyethylene glycol (PEG coated gold nanoparticles obtained by x-ray irradiation. Using two different cell lines, EMT and HeLa, we obtained the number of nanoparticle clusters uptaken by each cell and the cluster size. Furthermore, the analysis revealed interesting differences between 2D and 3D cultured cells as well as between 2D and 3D data for the same 3D specimen. Conclusions We demonstrated the feasibility and effectiveness of our method, proving that it is accurate enough to measure the nanoparticle uptake differences between cells as well as the sizes of the formed nanoparticle clusters. The differences between 2D and 3D cultures and 2D and 3D images stress the importance of the 3D analysis which is made possible by our approach.

  2. Windowless microfluidic platform based on capillary burst valves for high intensity x-ray measurements

    Energy Technology Data Exchange (ETDEWEB)

    Vig, Asger Laurberg; Enevoldsen, Nikolaj; Thilsted, Anil Haraksingh; Eriksen, Johan; Kristensen, Anders [Department of Micro and Nanotechnology, DTU Nanotech, Technical University of Denmark, Building 345east, Orsteds Plads, DK-2800 Kongens Lyngby (Denmark); Haldrup, Kristoffer; Feidenhans' l, Robert; Nielsen, Martin Meedom [Centre for Molecular Movies, Niels Bohr Institute, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen East (Denmark)

    2009-11-15

    We propose and describe a microfluidic system for high intensity x-ray measurements. The required open access to a microfluidic channel is provided by an out-of-plane capillary burst valve (CBV). The functionality of the out-of-plane CBV is characterized with respect to the diameter of the windowless access hole, ranging from 10 to 130 {mu}m. Maximum driving pressures from 22 to 280 mbar corresponding to refresh rates of the exposed sample from 300 Hz to 54 kHz is demonstrated. The microfluidic system is tested at beamline ID09b at the ESRF synchrotron radiation facility in Grenoble, and x-ray scattering measurements are shown to be feasible and to require only very limited amounts of sample, <1 ml/h of measurements without recapturing of sample. With small adjustments of the present chip design, scattering angles up to 30 deg. can be achieved without shadowing effects and integration on-chip mixing and spectroscopy appears straightforward.

  3. X-ray Interferometry with Transmissive Beam Combiners for Ultra-High Angular Resolution Astronomy

    Science.gov (United States)

    Skinner, G. K.; Krismanic, John F.

    2009-01-01

    Abstract Interferometry provides one of the possible routes to ultra-high angular resolution for X-ray and gamma-ray astronomy. Sub-micro-arc-second angular resolution, necessary to achieve objectives such as imaging the regions around the event horizon of a super-massive black hole at the center of an active galaxy, can be achieved if beams from parts of the incoming wavefront separated by 100s of meters can be stably and accurately brought together at small angles. One way of achieving this is by using grazing incidence mirrors. We here investigate an alternative approach in which the beams are recombined by optical elements working in transmission. It is shown that the use of diffractive elements is a particularly attractive option. We report experimental results from a simple 2-beam interferometer using a low-cost commercially available profiled film as the diffractive elements. A rotationally symmetric filled (or mostly filled) aperture variant of such an interferometer, equivalent to an X-ray axicon, is shown to offer a much wider bandpass than either a Phase Fresnel Lens (PFL) or a PFL with a refractive lens in an achromatic pair. Simulations of an example system are presented.

  4. THE AGES OF HIGH-MASS X-RAY BINARIES IN NGC 2403 AND NGC 300

    Energy Technology Data Exchange (ETDEWEB)

    Williams, Benjamin F.; Binder, Breanna A.; Dalcanton, Julianne J. [Department of Astronomy, Box 351580, University of Washington, Seattle, WA 98195 (United States); Eracleous, Michael [Department of Astronomy and Astrophysics and Center for Gravitational Wave Physics, Pennsylvania State University, 525 Davey Lab, University Park, PA 16803 (United States); Dolphin, Andrew, E-mail: ben@astro.washington.edu, E-mail: bbinder@astro.washington.edu, E-mail: jd@astro.washington.edu, E-mail: mce@astro.psu.edu, E-mail: adolphin@raytheon.com [Raytheon Company, Tucson, AZ 85734 (United States)

    2013-07-20

    We have examined resolved stellar photometry from HST imaging surrounding 18 high-mass X-ray binary (HMXB) candidates in NGC 300 and NGC 2403 as determined from combined Chandra/HST analysis. We have fit the color-magnitude distribution of the surrounding stars with stellar evolution models. All but one region in NGC 300 and two in NGC 2403 contain a population with an age between 20 and 70 Myr. One of the candidates is the ultraluminous X-ray source in NGC 2403, which we associate with a 60 {+-} 5 Myr old population. These age distributions provide additional evidence that 16 of these 18 candidates are HMXBs. Furthermore, our results suggest that the most common HMXB age in these galaxies is 40-55 Myr. This preferred age is similar to observations of HMXBs in the Small Magellanic Cloud, providing new evidence of this formation timescale, but in higher metallicity populations. We suggest that this preferred HMXB age is the result of the fortuitous combination of two physical effects. First, this is the age of a population when the greatest rate of core-collapse events should be occurring, maximizing neutron star production. Second, this is the age when B stars are most likely to be actively losing mass. We also discuss our results in the context of HMXB feedback in galaxies, confirming HMXBs as a potentially important source of energy for the interstellar medium in low-mass galaxies.

  5. Development of a high resolution x-ray spectrometer for the National Ignition Facility (NIF)

    Science.gov (United States)

    Hill, K. W.; Bitter, M.; Delgado-Aparicio, L.; Efthimion, P. C.; Ellis, R.; Gao, L.; Maddox, J.; Pablant, N. A.; Schneider, M. B.; Chen, H.; Ayers, S.; Kauffman, R. L.; MacPhee, A. G.; Beiersdorfer, P.; Bettencourt, R.; Ma, T.; Nora, R. C.; Scott, H. A.; Thorn, D. B.; Kilkenny, J. D.; Nelson, D.; Shoup, M.; Maron, Y.

    2016-11-01

    A high resolution (E/ΔE = 1200-1800) Bragg crystal x-ray spectrometer is being developed to measure plasma parameters in National Ignition Facility experiments. The instrument will be a diagnostic instrument manipulator positioned cassette designed mainly to infer electron density in compressed capsules from Stark broadening of the helium-β (1s2-1s3p) lines of krypton and electron temperature from the relative intensities of dielectronic satellites. Two conically shaped crystals will diffract and focus (1) the Kr Heβ complex and (2) the Heα (1s2-1s2p) and Lyα (1s-2p) complexes onto a streak camera photocathode for time resolved measurement, and a third cylindrical or conical crystal will focus the full Heα to Heβ spectral range onto an image plate to provide a time integrated calibration spectrum. Calculations of source x-ray intensity, spectrometer throughput, and spectral resolution are presented. Details of the conical-crystal focusing properties as well as the status of the instrumental design are also presented.

  6. High Speed Data Acquisition System for Three-Dimensional X-Ray and Neutron Computed Tomography

    Energy Technology Data Exchange (ETDEWEB)

    Davis, A.W.; Claytor, T.N.; Sheats, M.J.

    1999-07-01

    Computed tomography for nondestructive evaluation applications has been limited by system cost, resolution, and time requirements for three-dimensional data sets. FlashCT (Flat panel Amorphous Silicon High-Resolution Computed Tomography) is a system developed at Los Alamos National Laboratory to address these three problems. Developed around a flat panel amorphous silicon detector array, FlashCT is suitable for low to medium energy x-ray and neutron computed tomography at 127-micron resolution. Overall system size is small, allowing rapid transportation to a variety of radiographic sources. System control software was developed in LabVIEW for Windows NT to allow multithreading of data acquisition, data correction, and staging motor control. The system control software simplifies data collection and allows fully automated control of the data acquisition process, leading toward remote or unattended operation. The first generation of the FlashCT Data Acquisition System was completed in Au gust 1998, and since that time the system has been tested using x-ray sources ranging in energy from 60 kV to 20MV. The system has also been used to collect data for thermal neutron computed tomography at Los Alamos Neutron Science Center (LANSCE). System improvements have been proposed to provide faster data collection and greater dynamic range during data collection.

  7. Development of an ultra-high resolution diffraction grating forsoft x-rays

    Energy Technology Data Exchange (ETDEWEB)

    Voronov, Dmitriy L.; Cambie, Rossana; Feshchenko, Ruslan M.; Gullikson, Eric M.; Padmore, Howard A.; Vinogradov, Alexander V.; Yashchuk, Valeriy V.

    2007-08-21

    Resonant Inelastic X-ray Scattering (RIXS) is the one of themost powerful methods for investigation of the electronic structure ofmaterials, specifically of excitations in correlated electron systems.However the potential of the RIXS technique has not been fully exploitedbecause conventional grating spectrometers have not been capable ofachieving the extreme resolving powers that RIXS can utilize. State ofthe art spectrometers in the soft x-ray energy range achieve ~;0.25 eVresolution, compared to the energy scales of soft excitations andsuperconducting gap openings down to a few meV. Development ofdiffraction gratings with super high resolving power is necessary tosolve this problem. In this paper we study the possibilities offabrication of gratings of resolving power of up to 106 for the 0.5 1.5KeV energy range. This energy range corresponds to all or most of theuseful dipole transitions for elements of interest in most correlatedelectronic systems, i.e., oxygen K-edge of relevance to all oxides, thetransition metal L2,3 edges, and the M4,5 edges of the rare earths.Various approaches based on different kinds of diffraction gratings suchas deep-etched multilayer gratings, and multilayer coated echelettes arediscussed. We also present simulations of diffraction efficiency for suchgratings, and investigate the necessary fabricationtolerances.

  8. Spectroscopic Investigations of Highly Charged Ions using X-Ray Calorimeter Spectrometers

    Energy Technology Data Exchange (ETDEWEB)

    Thorn, Daniel Bristol [Univ. of California, Davis, CA (United States)

    2008-11-19

    Spectroscopy of K-shell transitions in highly charged heavy ions, like hydrogen-like uranium, has the potential to yield information about quantum electrodynamics (QED) in extremely strong nuclear fields as well as tests of the standard model, specifically parity violation in atomic systems. These measurements would represent the 'holy grail' in high-Z atomic spectroscopy. However, the current state-of-the-art detection schemes used for recording the K-shell spectra from highly charged heavy ions does not yet have the resolving power to be able to attain this goal. As such, to push the field of high-Z spectroscopy forward, new detectors must be found. Recently, x-ray calorimeter spectrometers have been developed that promise to make such measurements. In an effort to make the first steps towards attaining the 'holy grail', measurements have been performed with two x-ray calorimeter spectrometers (the XRS/EBIT and the ECS) designed and built at Goddard Space Flight Center in Greenbelt, MD. The calorimeter spectrometers have been used to record the K-shell spectra of highly charged ions produced in the SuperEBIT electron beam ion trap at Lawrence Livermore National Laboratory in Livermore, CA. Measurements performed with the XRS/EBIT calorimeter array found that the theoretical description of well-above threshold electron-impact excitation cross sections for hydrogen-like iron and nickel ions are correct. Furthermore, the first high-resolution spectrum of hydrogen-like through carbon-like praseodymium ions was recorded with a calorimeter. In addition, the new high-energy array on the EBIT Calorimeter Spectrometer (ECS) was used to resolve the K-shell x-ray emission spectrum of highly charged xenon ions, where a 40 ppm measurement of the energy of the K-shell resonance transition in helium-like xenon was achieved. This is the highest precision result, ever, for an element with such high atomic number. In addition, a first-of-its-kind measurement of

  9. High-energy X-rays from J174545.5-285829, the cannonball: a candidate pulsar wind nebula associated with SGR a east

    DEFF Research Database (Denmark)

    Nynka, Melania; Hailey, Charles J.; Mori, Kaya

    2013-01-01

    We report the unambiguous detection of non-thermal X-ray emission up to 30 keV from the Cannonball, a few-arcsecond long diffuse X-ray feature near the Galactic Center, using the NuSTAR X-ray observatory. The Cannonball is a high-velocity ( v proj ~ 500 km s-1) pulsar candidate with a cometary...

  10. Multi-anode linear SDDs for high-resolution X-ray spectroscopy

    NARCIS (Netherlands)

    Sonsky, J.

    2002-01-01

    Radiation detectors are used in a variety of fields to sense X-rays and y-rays, visible, UV and IR photons, neutrons or charged particles. With their help, advanced medical diagnostics can be performed (e.g. X-ray radiography, computed tomography, fluoroscopy), material research can undergo a rapid

  11. Luminosity Dependent Study of the High Mass X-ray Binary Pulsar ...

    Indian Academy of Sciences (India)

    1997-02-10

    Feb 10, 1997 ... these spectral characteristics as observed with ASCA with those of other satellites. We also compare ... periodicity has been observed in the X-ray light curves of 4U 0114 + 65 from the analysis of archival ... The X-ray spectrum emanating from the pulsar is nicely fitted with a generic model applicable in the ...

  12. X-ray emission from charge exchange of highly-charged ions in atoms and molecules

    Science.gov (United States)

    Greenwood, J. B.; Williams, I. D.; Smith, S. J.; Chutjian, A.

    2000-01-01

    Charge exchange followed by radiative stabilization are the main processes responsible for the recent observations of X-ray emission from comets in their approach to the Sun. A new apparatus was constructed to measure, in collisions of HCIs with atoms and molecules, (a) absolute cross sections for single and multiple charge exchange, and (b) normalized X-ray emission cross sections.

  13. High-resolution X-ray diffraction with no sample preparation.

    Science.gov (United States)

    Hansford, G M; Turner, S M R; Degryse, P; Shortland, A J

    2017-07-01

    It is shown that energy-dispersive X-ray diffraction (EDXRD) implemented in a back-reflection geometry is extremely insensitive to sample morphology and positioning even in a high-resolution configuration. This technique allows high-quality X-ray diffraction analysis of samples that have not been prepared and is therefore completely non-destructive. The experimental technique was implemented on beamline B18 at the Diamond Light Source synchrotron in Oxfordshire, UK. The majority of the experiments in this study were performed with pre-characterized geological materials in order to elucidate the characteristics of this novel technique and to develop the analysis methods. Results are presented that demonstrate phase identification, the derivation of precise unit-cell parameters and extraction of microstructural information on unprepared rock samples and other sample types. A particular highlight was the identification of a specific polytype of a muscovite in an unprepared mica schist sample, avoiding the time-consuming and difficult preparation steps normally required to make this type of identification. The technique was also demonstrated in application to a small number of fossil and archaeological samples. Back-reflection EDXRD implemented in a high-resolution configuration shows great potential in the crystallographic analysis of cultural heritage artefacts for the purposes of scientific research such as provenancing, as well as contributing to the formulation of conservation strategies. Possibilities for moving the technique from the synchrotron into museums are discussed. The avoidance of the need to extract samples from high-value and rare objects is a highly significant advantage, applicable also in other potential research areas such as palaeontology, and the study of meteorites and planetary materials brought to Earth by sample-return missions.

  14. Robust, high-throughput solution structural analyses by small angle X-ray scattering (SAXS)

    Energy Technology Data Exchange (ETDEWEB)

    Hura, Greg L.; Menon, Angeli L.; Hammel, Michal; Rambo, Robert P.; Poole II, Farris L.; Tsutakawa, Susan E.; Jenney Jr, Francis E.; Classen, Scott; Frankel, Kenneth A.; Hopkins, Robert C.; Yang, Sungjae; Scott, Joseph W.; Dillard, Bret D.; Adams, Michael W. W.; Tainer, John A.

    2009-07-20

    We present an efficient pipeline enabling high-throughput analysis of protein structure in solution with small angle X-ray scattering (SAXS). Our SAXS pipeline combines automated sample handling of microliter volumes, temperature and anaerobic control, rapid data collection and data analysis, and couples structural analysis with automated archiving. We subjected 50 representative proteins, mostly from Pyrococcus furiosus, to this pipeline and found that 30 were multimeric structures in solution. SAXS analysis allowed us to distinguish aggregated and unfolded proteins, define global structural parameters and oligomeric states for most samples, identify shapes and similar structures for 25 unknown structures, and determine envelopes for 41 proteins. We believe that high-throughput SAXS is an enabling technology that may change the way that structural genomics research is done.

  15. High-precision soft x-ray polarimeter at Diamond Light Source.

    Science.gov (United States)

    Wang, H; Dhesi, S S; Maccherozzi, F; Cavill, S; Shepherd, E; Yuan, F; Deshmukh, R; Scott, S; van der Laan, G; Sawhney, K J S

    2011-12-01

    The development and performance of a high-precision polarimeter for the polarization analysis in the soft x-ray region is presented. This versatile, high-vacuum compatible instrument is supported on a hexapod to simplify the alignment with a resolution less than 5 μrad, and can be moved with its own independent control system easily between different beamlines and synchrotron facilities. The polarimeter can also be used for the characterization of reflection and transmission properties of optical elements. A W/B(4)C multilayer phase retarder was used to characterize the polarization state up to 1200 eV. A fast and accurate alignment procedure was developed, and complete polarization analysis of the APPLE II undulator at 712 eV has been performed.

  16. High-precision soft x-ray polarimeter at Diamond Light Source

    Science.gov (United States)

    Wang, H.; Dhesi, S. S.; Maccherozzi, F.; Cavill, S.; Shepherd, E.; Yuan, F.; Deshmukh, R.; Scott, S.; van der Laan, G.; Sawhney, K. J. S.

    2011-12-01

    The development and performance of a high-precision polarimeter for the polarization analysis in the soft x-ray region is presented. This versatile, high-vacuum compatible instrument is supported on a hexapod to simplify the alignment with a resolution less than 5 μrad, and can be moved with its own independent control system easily between different beamlines and synchrotron facilities. The polarimeter can also be used for the characterization of reflection and transmission properties of optical elements. A W/B4C multilayer phase retarder was used to characterize the polarization state up to 1200 eV. A fast and accurate alignment procedure was developed, and complete polarization analysis of the APPLE II undulator at 712 eV has been performed.

  17. High precision X-ray spectroscopy in hydrogen-like fermionic and bosonic atomic systems

    Energy Technology Data Exchange (ETDEWEB)

    Borchert, G.L.; Anagnostopoulos, D.; Augsburger, M.; Belmiloud, D.; Castelli, C.; Chatellard, D.; Daum, M.; Egger, J.P.; El-Khoury, P.; Elble, M.; Frosch, R.; Gorke, H.; Gotta, D.; Hauser, P.; Indelicato, P.; Kirch, K.; Lenz, S.; Nelms, N.; Rashid, K.; Schult, O.W.B. (and others)

    1998-11-15

    Some time after its formation an exotic atom may be considered a hydrogen-like system consisting of a nucleus and an exotic particle in a bound state. In this situation it is an ideal tool to study cascade properties, while for the innermost orbits it can be used to probe the interaction with the nucleus. From an extended series of experiments using high resolution X-ray spectroscopy for both aspects typical examples are reported and preliminary results are given: 1. To determine the complex scattering length in p-barH the 3D{yields}2P hyperfine transitions have been measured. 2. To determine the pion mass the 5 {yields} 4 transitions in {pi}{sup 14}N have been studied. In all cases a major contribution to the uncertainty originates from the calibration. Therefore a new method is proposed that will establish a universal set of high precision calibration lines for pionic, muonic and electronic systems.

  18. Metrology for the Development of High Energy X-Ray Optics

    Science.gov (United States)

    Gubarev, Mikhail; Ramsey, Brian; Engelhaupt, Darell; Dpeegle, Chet

    2005-01-01

    We are developing grazing incidence x-ray optics for a balloon-borne hard-x-ray telescope (HERO). The instrument will have 200 sq cm effective collecting area at 40 keV and an angular resolution goal of 15 arcsec. The HERO mirror shells are fabricated using electroform-nickel replication off super-polished cylindrical mandrels. The angular resolution goal puts stringent requirements on the quality of x-ray mirrors and, hence, on mandrel quality. We used metrology in an iterative approach to monitor and refine the x- ray mirror fabrication process. Comparison of surface figure and microroughness measurements of the mandrel and the shells will be presented together with results from x-ray tests.

  19. High-Resolution X-Ray Spectroscopy of Galactic Supernova Remnants

    Directory of Open Access Journals (Sweden)

    Satoru Katsuda

    2014-12-01

    Full Text Available High-resolution X-ray spectroscopy of Galactic supernova remnants (SNRs, based on grating spectrometers onboard XMM-Newton and Chandra, has been revealing a variety of new astrophysical phenomena. Broadened oxygen lines for a northwestern compact knot in SN 1006 clearly show a high oxygen temperature of ~300 keV. The high temperature together with a lower electron temperature (kTe ~ 1 keV can be reasonably interpreted as temperature non-equilibration between electrons and oxygen behind a collisionless shock. An ejecta knot in the Puppis A SNR shows blueshifted line emission by ~ 1500kms-1. The line widths are fairly narrow in contrast to the SN 1006's knot; an upper limit of 0.9 eV is obtained for O VIII Lyα, which translates to an oxygen temperature of kTO < 30 keV. The low temperature suggests that the knot was heated by a reverse shock whose velocity is 4 times slower than that of a forward shock. Anomalous intensity ratios in O VII Heα lines, i.e., a stronger forbidden line than a resonance line, is found in a cloud-shock interaction region in Puppis A. The line ratio can be best explained by the charge-exchange emission that should arise at interfaces between the cold/warm clouds and the hot plasma. There are several other targets for which we plan to analyze high-quality grating data prior to the operation of the soft X-ray spectrometer onboard Astro-H.

  20. High-energy X-ray optics with silicon saw-tooth refractive lenses.

    Science.gov (United States)

    Shastri, S D; Almer, J; Ribbing, C; Cederström, B

    2007-03-01

    Silicon saw-tooth refractive lenses have been in successful use for vertical focusing and collimation of high-energy X-rays (50-100 keV) at the 1-ID undulator beamline of the Advanced Photon Source. In addition to presenting an effectively parabolic thickness profile, as required for aberration-free refractive optics, these devices allow high transmission and continuous tunability in photon energy and focal length. Furthermore, the use of a single-crystal material (i.e. Si) minimizes small-angle scattering background. The focusing performance of such saw-tooth lenses, used in conjunction with the 1-ID beamline's bent double-Laue monochromator, is presented for both short ( approximately 1:0.02) and long ( approximately 1:0.6) focal-length geometries, giving line-foci in the 2 microm-25 microm width range with 81 keV X-rays. In addition, a compound focusing scheme was tested whereby the radiation intercepted by a distant short-focal-length lens is increased by having it receive a collimated beam from a nearer (upstream) lens. The collimation capabilities of Si saw-tooth lenses are also exploited to deliver enhanced throughput of a subsequently placed small-angular-acceptance high-energy-resolution post-monochromator in the 50-80 keV range. The successful use of such lenses in all these configurations establishes an important detail, that the pre-monochromator, despite being comprised of vertically reflecting bent Laue geometry crystals, can be brilliance-preserving to a very high degree.

  1. High resolution X-ray fluorescence imaging for a microbeam radiation therapy treatment planning system

    Science.gov (United States)

    Chtcheprov, Pavel; Inscoe, Christina; Burk, Laurel; Ger, Rachel; Yuan, Hong; Lu, Jianping; Chang, Sha; Zhou, Otto

    2014-03-01

    Microbeam radiation therapy (MRT) uses an array of high-dose, narrow (~100 μm) beams separated by a fraction of a millimeter to treat various radio-resistant, deep-seated tumors. MRT has been shown to spare normal tissue up to 1000 Gy of entrance dose while still being highly tumoricidal. Current methods of tumor localization for our MRT treatments require MRI and X-ray imaging with subject motion and image registration that contribute to the measurement error. The purpose of this study is to develop a novel form of imaging to quickly and accurately assist in high resolution target positioning for MRT treatments using X-ray fluorescence (XRF). The key to this method is using the microbeam to both treat and image. High Z contrast media is injected into the phantom or blood pool of the subject prior to imaging. Using a collimated spectrum analyzer, the region of interest is scanned through the MRT beam and the fluorescence signal is recorded for each slice. The signal can be processed to show vascular differences in the tissue and isolate tumor regions. Using the radiation therapy source as the imaging source, repositioning and registration errors are eliminated. A phantom study showed that a spatial resolution of a fraction of microbeam width can be achieved by precision translation of the mouse stage. Preliminary results from an animal study showed accurate iodine profusion, confirmed by CT. The proposed image guidance method, using XRF to locate and ablate tumors, can be used as a fast and accurate MRT treatment planning system.

  2. X-ray microanalysis of biological specimens by high voltage electron microscopy.

    Science.gov (United States)

    Nagata, Tetsuji

    2004-01-01

    For the purpose of analyzing and imaging chemical components of cells and tissues at the electron microscopic level, 3 fundamental methods are available, chemical, physical and biological. Among the physical methods, two methods qualifying and quantifying the elements in the structural components are very often employed. The first method is radioautography which can demonstrate the localization of radiolabeled compounds which were incorporated into cells and tissues after the administration of radiolabeled compounds. The second method is X-ray microanalysis which can qualitatively analyze and quantify the total amounts of elements present in cells and tissues. We have developed the two methodologies in combination with intermediate high or high voltage transmission electron microscopy (200-400 kV) and applied them to various kinds of organic and inorganic compounds present in biological materials. As for the first method, radioautography, I had already contributed a chapter to PHC (37/2). To the contrary, this review deals with another method, X-ray microanalysis, using semi-thin sections and intermediate high voltage electron microscopy developed in our laboratory. X-ray microanalysis is a useful method to qualify and quantify basic elements in biological specimens. We first quantified the end-products of histochemical reactions such as Ag in radioautographs, Ce in phosphatase reaction and Au in colloidal gold immunostaining using semithin sections and quantified the reaction products observing by intermediate high voltage transmission electron microscopy at accelerating voltages from 100 to 400 kV. The P/B ratios of all the end products Ag, Ce and Au increased with the increase of the accelerating voltages from 100 to 400 kV. Then we analyzed various trace elements such as Zn, Ca, S and Cl which originally existed in cytoplasmic matrix or cell organelles of various cells, or such elements as Al which was absorbed into cells and tissues after oral administration

  3. AXIS - A High Angular Resoltuion X-ray Probe Concept Study

    Science.gov (United States)

    Mushotzky, Richard; AXIS Study Team

    2018-01-01

    AXIS is a probe-class concept under study to the 2020 Decadal survey. AXIS will extend and enhance the science of high angular resolution x-ray imaging and spectroscopy in the next decade with ~0.3" angular resolution over a 7' radius field of view and an order of magnitude more collecting area than Chandra in the 0.3-12 keV band with a cost consistent with a probe.These capabilities enable major advances in a wide range of science such as: (1) measuring the event horizon scale structure in AGN accretion disks and the spins of supermassive black holes through observations of gravitationally-microlensed quasars; (ii) determining AGN and starburst feedback in galaxies and galaxy clusters through direct imaging of winds and interaction of jets and via spatially resolved imaging of galaxies at high-z; (iii) fueling of AGN by probing the Bondi radius of over 20 nearby galaxies; (iv) hierarchical structure formation and the SMBH merger rate through measurement of the occurrence rate of dual AGN and occupation fraction of SMBHs; (v) advancing SNR physics and galaxy ecology through large detailed samples of SNR in nearby galaxies; (vi) measuring the Cosmic Web through its connection to cluster outskirts. With a nominal 2028 launch, AXIS benefits from natural synergies with the ELTs, LSST, ALMA, WFIRST and ATHENA. AXIS utilizes breakthroughs in the construction of lightweight X-ray optics from mono-crystalline silicon blocks, and developments in the fabrication of large format, small pixel, high readout rate detectors allowing a robust and cost effective design. The AXIS team welcomes input and feedback from the community in preparation for the 2020 Decadal review.

  4. Investigating the suitability of GaAs:Cr material for high flux X-ray imaging

    Science.gov (United States)

    Veale, M. C.; Bell, S. J.; Duarte, D. D.; French, M. J.; Hart, M.; Schneider, A.; Seller, P.; Wilson, M. D.; Kachkanov, V.; Lozinskaya, A. D.; Novikov, V. A.; Tolbanov, O. P.; Tyazhev, A.; Zarubin, A. N.

    2014-12-01

    Semi-insulating wafers of GaAs material with a thickness of 500μm have been compensated with chromium by Tomsk State University. Initial measurements have shown the material to have high resistivity (3 × 109Ωcm) and tests with pixel detectors on a 250 μm pitch produced uniform spectroscopic performance across an 80 × 80 pixel array. At present, there is a lack of detectors that are capable of operating at high X-ray fluxes (> 108 photons s-1 mm-2) in the energy range 5-50 keV. Under these conditions, the poor stopping power of silicon, as well as issues with radiation hardness, severely degrade the performance of traditional detectors. While high-Z materials such as CdTe and CdZnTe may have much greater stopping power, the formation of space charge within these detectors degrades detector performance. Initial measurements made with GaAs:Cr detectors suggest that many of its material properties make it suitable for these challenging conditions. In this paper the radiation hardness of the GaAs:Cr material has been measured on the B16 beam line at the Diamond Light Source synchrotron. Small pixel detectors were bonded to the STFC Hexitec ASIC and were irradiated with 3 × 108 photons s-1 mm-2 monochromatic 12 keV X-rays up to a maximum dose of 0.6 MGy. Measurements of the spectroscopic performance before and after irradiation have been used to assess the extent of the radiation damage.

  5. Segmented phosphors: MEMS-based high quantum efficiency detectors for megavoltage x-ray imaging.

    Science.gov (United States)

    Sawant, Amit; Antonuk, Larry E; El-Mohri, Youcef; Li, Yixin; Su, Zhong; Wang, Yi; Yamamoto, Jin; Zhao, Qihua; Du, Hong; Daniel, Jurgen; Street, Robert

    2005-02-01

    Current electronic portal imaging devices (EPIDs) based on active matrix flat panel imager (AMFPI) technology use a metal plate+phosphor screen combination for x-ray conversion. As a result, these devices face a severe trade-off between x-ray quantum efficiency (QE) and spatial resolution, thus, significantly limiting their imaging performance. In this work, we present a novel detector design for indirect detection-based AMFPI EPIDs that aims to circumvent this trade-off. The detectors were developed using micro-electro-mechanical system (MEMS)-based fabrication techniques and consist of a grid of up to approximately 2 mm tall, optically isolated cells of a photoresist material, SU-8. The cells are dimensionally matched to the pixels of the AMFPI array, and packed with a scintillating phosphor. In this paper, various design considerations for such detectors are examined. An empirical evaluation of three small-area (approximately 7 x 7 cm2) prototype detectors is performed in order to study the effects of two design parameters--cell height and phosphor packing density, both of which are important determinants of the imaging performance. Measurements of the x-ray sensitivity, modulation transfer function (MTF) and noise power spectrum (NPS) were performed under radiotherapy conditions (6 MV), and the detective quantum efficiency (DQE) was determined for each prototype SU-8 detector. In addition, theoretical calculations using Monte Carlo simulations were performed to determine the QE of each detector, as well as the inherent spatial resolution due to the spread of absorbed energy. The results of the present studies were compared with corresponding measurements published in an earlier study using a Lanex Fast-B phosphor screen coupled to an indirect detection array of the same design. The SU-8 detectors exhibit up to 3 times higher QE, while achieving spatial resolution comparable or superior to Lanex Fast-B. However, the DQE performance of these early prototypes is

  6. High Resolution X-ray Computed Tomography: An Emerging Tool for Small Animal Cancer Research

    Directory of Open Access Journals (Sweden)

    Michael J. Paulus

    2000-01-01

    Full Text Available Dedicated high-resolution small animal imaging systems have recently emerged as important new tools for cancer research. These new imaging systems permit researchers to noninvasively screen animals for mutations or pathologies and to monitor disease progression and response to therapy. One imaging modality, X-ray microcomputed tomography (microCT shows promise as a cost-effective means for detecting and characterizing soft-tissue structures, skeletal abnormalities, and tumors in live animals. MicroCT systems provide highresolution images (typically 50 microns or less, rapid data acquisition (typically 5 to 30 minutes, excellent sensitivity to skeletal tissue and good sensitivity to soft tissue, particularly when contrast-enhancing media are employed. The development of microCT technology for small animal imaging is reviewed, and key considerations for designing small animal microCT imaging protocols are summarized. Recent studies on mouse prostate, lung and bone tumor models are overviewed.

  7. Development of a High Resolution X-ray Spectrometer on the National Ignition Facility

    Science.gov (United States)

    Gao, L.; Kraus, B.; Hill, K. W.; Bitter, M.; Efthimion, P.; Schneider, M. B.; Chen, H.; Ayers, J.; Liedahl, D.; Macphee, A. G.; Le, H. P.; Thorn, D.; Nelson, D.

    2017-10-01

    A high-resolution x-ray spectrometer has been designed, calibrated, and deployed on the National Ignition Facility (NIF) to measure plasma parameters for a Kr-doped surrogate capsule imploded at NIF conditions. Two conical crystals, each diffracting the He α and He β complexes respectively, focus the spectra onto a steak camera photocathode for time-resolved measurements with a temporal resolution of NIF experimental results will also be discussed. This work was performed under the auspices of the U.S. Department of Energy by Princeton Plasma Physics Laboratory under contract DE-AC02-09CH11466 and by Lawrence Livermore National Laboratory under contract DE-AC52-07NA27344.

  8. High-resolution X-ray absorption spectroscopy of iron carbonyl complexes.

    Science.gov (United States)

    Atkins, Andrew J; Bauer, Matthias; Jacob, Christoph R

    2015-06-07

    We apply high-energy-resolution fluorescence-detected (HERFD) X-ray absorption near-edge spectroscopy (XANES) to study iron carbonyl complexes. Mono-, bi-, and tri-nuclear carbonyl complexes and pure carbonyl complexes as well as carbonyl complexes containing hydrocarbon ligands are considered. The HERFD-XANES spectra reveal multiple pre-edge peaks with individual signatures for each complex, which could not be detected previously with conventional XANES spectroscopy. These peaks are assigned and analysed with the help of TD-DFT calculations. We demonstrate that the pre-edge peaks can be used to distinguish the different types of iron-iron interactions in carbonyl complexes. This opens up new possibilities for applying HERFD-XANES spectroscopy to probe the electronic structure of iron catalysts.

  9. Conception of broadband stigmatic high-resolution spectrometers for the soft X-ray range

    Energy Technology Data Exchange (ETDEWEB)

    Vishnyakov, E A; Shatokhin, A N; Ragozin, E N [P N Lebedev Physics Institute, Russian Academy of Sciences, Moscow (Russian Federation)

    2015-04-30

    We formulate an approach to the development of stigmatic high-resolution spectral instruments for the soft X-ray range (λ ≤ 300 Å), which is based on the combined operation of normalincidence multilayer mirrors (including broadband aperiodic ones) and grazing-incidence reflection gratings with nonequidistant grooves (so-called VLS gratings). A concave multilayer mirror serves to produce a slightly astigmatic image of the radiation source (for instance, an entrance slit), and the diffraction grating produces a set of its dispersed stigmatic spectral images. The width of the operating spectral region is determined by the aperiodic structure of the multilayer mirror and may range up to an octave in wavelength. (laser applications and other topics in quantum electronics)

  10. Applied x-ray computed tomography with high resolution in paleontology using laboratory and synchrotron sources

    Science.gov (United States)

    Bidola, Pidassa; Pacheco, Mirian L. A. F.; Stockmar, Marco K.; Achterhold, Klaus; Pfeiffer, Franz; Beckmann, Felix; Tafforeau, Paul; Herzen, Julia

    2014-09-01

    X-ray computed tomography (CT) has become an established technique in the biomedical imaging or materials science research. Its ability to non-destructively provide high-resolution images of samples makes it attractive for diverse fields of research especially the paleontology. Exceptionally, the Precambrian is a geological time of rocks deposition containing several fossilized early animals, which still need to be investigated in order to predict the origin and evolution of early life. Corumbella werneri is one of those fossils skeletonized in Corumbá (Brazil). Here, we present a study on selected specimens of Corumbella werneri using absorption-based contrast imaging at diverse tomographic setups. We investigated the potential of conventional laboratory-based device and synchrotron radiation sources to visualize internal structures of the fossils. The obtained results are discussed as well as the encountered limitations of those setups.

  11. High-fidelity X-ray micro-tomography reconstruction of siderite-hosted Carboniferous arachnids

    Science.gov (United States)

    Garwood, Russell; Dunlop, Jason A.; Sutton, Mark D.

    2009-01-01

    A new approach to maximize data recovery from siderite-hosted fossils is presented. Late Carboniferous trigonotarbids (Arachnida: Trigonotarbida) from Coseley, UK, were chosen to assess the potential of high-resolution X-ray micro-tomography (XMT). Three-dimensional computer reconstruction visualizes the animals at 20 µm or better resolution, resolving subtle and previously unseen details. Novel data recovered includes (possibly plesiomorphic) retention of endites on leg coxae of Cryptomartus hindi (Anthracomartidae) and highlights further similarities between this family and the Devonian Palaeocharinidae. Also revealed is a flattened body with robust anterior limbs, implying a hunting stance similar to modern crab spiders (Thomisidae). Eophrynus prestvicii (Eophrynidae) had more gracile limbs but a heavily ornamented body, with newly identified upward-pointing marginal spines on the opisthosoma. Its habitus is comparable with certain modern laniatorid harvestmen (Opiliones). These findings demonstrate the potential of XMT to revolutionize the study of siderite-hosted Coal Measures fossils. PMID:19656861

  12. High-fidelity X-ray micro-tomography reconstruction of siderite-hosted Carboniferous arachnids.

    Science.gov (United States)

    Garwood, Russell; Dunlop, Jason A; Sutton, Mark D

    2009-12-23

    A new approach to maximize data recovery from siderite-hosted fossils is presented. Late Carboniferous trigonotarbids (Arachnida: Trigonotarbida) from Coseley, UK, were chosen to assess the potential of high-resolution X-ray micro-tomography (XMT). Three-dimensional computer reconstruction visualizes the animals at 20 microm or better resolution, resolving subtle and previously unseen details. Novel data recovered includes (possibly plesiomorphic) retention of endites on leg coxae of Cryptomartus hindi (Anthracomartidae) and highlights further similarities between this family and the Devonian Palaeocharinidae. Also revealed is a flattened body with robust anterior limbs, implying a hunting stance similar to modern crab spiders (Thomisidae). Eophrynus prestvicii (Eophrynidae) had more gracile limbs but a heavily ornamented body, with newly identified upward-pointing marginal spines on the opisthosoma. Its habitus is comparable with certain modern laniatorid harvestmen (Opiliones). These findings demonstrate the potential of XMT to revolutionize the study of siderite-hosted Coal Measures fossils.

  13. X-Ray CT of Highly-Attenuating Objects: 9- or 15- MV Spectra?

    Energy Technology Data Exchange (ETDEWEB)

    Stone, G; Trebes, J; Perry, R; Schneberk, D; Logan, C

    2005-08-29

    We imaged-highly attenuating test objects in three dimensions with 9-MV (at LLNL) and 15-MV (at Hill Air Force Base) x-ray spectra. While we used the same detector and motion control, there were differences that we could not control in the two radiography bays and in the sources. The results show better spatial resolution for the 9-MV spectrum and better contrast for the 15-MV spectrum. The 15-MV data contains a noise pattern that obfuscates the data. It is our judgment that if sufficient attention were given to design of the bay, beam dump, collimation, filtration and linac spot size; a 15-MV imaging system using a flat panel could be developed with spatial resolution of 5 lp/mm and contrastive performance better than we have demonstrated using a 9-MV spectrum.

  14. Direct Structural Observation of a Molecular Junction by High-Energy X-ray Reflectometry

    Energy Technology Data Exchange (ETDEWEB)

    Lefenfeld,M.; Baumert, J.; Sloutskin, E.; Kuzmenko, I.; Pershan, P.; Deutsch, M.; Nuckolls, C.; Ocko, B.

    2006-01-01

    We report a direct angstrom resolution measurement of the structure of a molecular-size electronic junction comprising a single (or a double) layer of alkyl-thiol and alkyl-silane molecules at the buried interface between solid silicon and liquid mercury. The high-energy synchrotron x-ray measurements reveal densely packed layers comprising roughly interface-normal molecule . The monolayer's thickness is found to be 3-4 Angstroms larger than that of similar layers at the free surfaces of both mercury and silicon. The origins of this and the other unusual features detected are discussed in this article. Measurements of the bilayer junction with an applied potential did not show visible changes in the surface normal structure.

  15. Spectral evolution of soft x-ray emission from optically thin, high electron temperature platinum plasmas

    Directory of Open Access Journals (Sweden)

    Hiroyuki Hara

    2017-08-01

    Full Text Available The soft x-ray spectra of heavy element plasmas are frequently dominated by unresolved transition array (UTA emission. We describe the spectral evolution of an intense UTA under optically thin conditions in platinum plasmas. The UTA was observed to have a peak wavelength around 4.6 nm at line-of-sight averaged electron temperatures less than 1.4 keV at electron densities of (2.5–7.5 × 1013 cm−3. The UTA spectral structure was due to emission from 4d–4f transitions in highly charged ions with average charge states of q = 20–40. A numerical simulation successfully reproduced the observed spectral behavior.

  16. Spectral evolution of soft x-ray emission from optically thin, high electron temperature platinum plasmas

    Science.gov (United States)

    Hara, Hiroyuki; Ohashi, Hayato; Li, Bowen; Dunne, Padraig; O'Sullivan, Gerry; Sasaki, Akira; Suzuki, Chihiro; Tamura, Naoki; Sakaue, Hiroyuki A.; Kato, Daiji; Murakami, Izumi; Higashiguchi, Takeshi; LHD Experiment Group

    2017-08-01

    The soft x-ray spectra of heavy element plasmas are frequently dominated by unresolved transition array (UTA) emission. We describe the spectral evolution of an intense UTA under optically thin conditions in platinum plasmas. The UTA was observed to have a peak wavelength around 4.6 nm at line-of-sight averaged electron temperatures less than 1.4 keV at electron densities of (2.5-7.5) × 1013 cm-3. The UTA spectral structure was due to emission from 4d-4f transitions in highly charged ions with average charge states of q = 20-40. A numerical simulation successfully reproduced the observed spectral behavior.

  17. High-pressure X-ray diffraction study of bulk- and nanocrystalline GaN

    DEFF Research Database (Denmark)

    Jorgensen, J.E.; Jakobsen, J.M.; Jiang, Jianzhong

    2003-01-01

    Bulk- and nanocrystalline GaN have been studied by high-pressure energy-dispersive X-ray diffraction. Pressure-induced structural phase transitions from the wurtzite to the NaCl phase were observed in both materials. The transition pressure was found to be 40 GPa for the bulk-crystalline GaN, while...... the wurtzite phase was retained up to 60 GPa in the case of nanocrystalline GaN. The bulk moduli for the wurtzite phases were determined to be 187 ( 7) and 319 ( 10) GPa for the bulk- and nanocrystalline phases, respectively, while the respective NaCl phases were found to have very similar bulk moduli [ 208...

  18. Atomic physics studies of highly charged ions on tokamaks using x-ray spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

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

    1989-07-01

    An overview is given of atomic physics issues which have been studied on tokamaks with the help resolution x-ray spectroscopy. The issues include the testing of model calculations predicting the excitation of line radiation, the determination of rate coefficients, and accurate atomic structure measurements. Recent research has focussed primarily on highly charged heliumlike (22 less than or equal to Z less than or equal to 28) and neonlike (34 less than or equal to Z less than or equal to 63) ions, and results are presented from measurements on the PLT and TFTR tokamaks. Many of the measurements have been aided by improved instrumental design and new measuring techniques. Remarkable agreement has been found between measurements and theory in most cases. However, in this review those areas are stressed where agreement is worst and where further investigations are needed. 19 refs., 13 figs., 2 tabs.

  19. High-efficiency diffractive x-ray optics from sectioned multilayers

    Energy Technology Data Exchange (ETDEWEB)

    Kang, H C; Stephenson, G B; Liu, C; Conley, R; Macrander, A T; Maser, J; Bajt, S; Chapman, H N

    2004-12-14

    We investigate the diffraction properties of sectioned multilayers in Laue (transmission) geometry, at hard x-ray energies (9.5 and 19.5 keV). Two samples are studied, a 200 period W/Si multilayer of 29 nm d-spacing, and a 2020 period Mo/Si multilayer of 7 nm d-spacing, with cross-section depths ranging from 2 to 17 {micro}m. Rocking curves across the Bragg reflections exhibit well-defined interference fringes originating from the depth of the sample. Efficiencies as high as 70% were obtained. This exceeds the theoretical limit for standard zone plates operating in the multi-beam regime, demonstrating that all of the intensity can be directed into a single diffraction order in small-period structures.

  20. High Resolution Energetic X-ray Imager (HREXI) for a Prototype 12U CubeSat

    Science.gov (United States)

    Hong, JaeSub; Allen, Branden; Grindlay, Jonathan E.; Barthelmy, Scott Douglas; Harrison, Fiona

    2017-08-01

    Our High Resolution Energetic X-ray Imager (HREXI) program is developing an Engineering Model (EM) for a 12U CubeSat wide-field hard X-ray (3-200 keV) coded-aperture imaging telescope. HREXI employs an array of CdZnTe (CZT) detectors (each 2 x 2 x 0.3 cm) with a fine-pixellated Tungsten coded aperture mask. The detector assembly utilizes the new technology of Through-Silicon-Vias (TSVs) to control and readout signals from the ASIC bonded to each CZT. TSVs eliminate the need for conventional wire-bonds for electric connections between the ASIC and back end electronics, greatly lowering the assembly complexity and cost, and thus enabling close-tiling of HREXI detectors in a small form factor with comfortable margins. For HREXI EM, we have successfully implemented TSVs on NuSTAR ASICs, which can cover an energy range of 3-200 keV with a FWHM spectral resolution of 1-2 keV. The 12U CubeSat HREXI EM prototype with 64 CZT detectors would image 0.5 sr of sky with FWHM field of view with 11 arcmin resolution for the current generation of the TSV-ASIC and a 20 cm mask - detector plane separation. A flight test of this 12U-HREXI will be proposed after full development and environmental testing to enable a future proposed array of SmallSat-HREXI telescopes with ~2 arcmin resolution for simultaneous full-sky studies of high redshift GRBs and a wide range of transients in the post-Swift era. (This work is supported by NASA grant NNX17AE62G)

  1. Meta-shell Approach for Constructing Lightweight and High Resolution X-Ray Optics

    Science.gov (United States)

    McClelland, Ryan S.

    2016-01-01

    Lightweight and high resolution optics are needed for future space-based x-ray telescopes to achieve advances in high-energy astrophysics. Past missions such as Chandra and XMM-Newton have achieved excellent angular resolution using a full shell mirror approach. Other missions such as Suzaku and NuSTAR have achieved lightweight mirrors using a segmented approach. This paper describes a new approach, called meta-shells, which combines the fabrication advantages of segmented optics with the alignment advantages of full shell optics. Meta-shells are built by layering overlapping mirror segments onto a central structural shell. The resulting optic has the stiffness and rotational symmetry of a full shell, but with an order of magnitude greater collecting area. Several meta-shells so constructed can be integrated into a large x-ray mirror assembly by proven methods used for Chandra and XMM-Newton. The mirror segments are mounted to the meta-shell using a novel four point semi-kinematic mount. The four point mount deterministically locates the segment in its most performance sensitive degrees of freedom. Extensive analysis has been performed to demonstrate the feasibility of the four point mount and meta-shell approach. A mathematical model of a meta-shell constructed with mirror segments bonded at four points and subject to launch loads has been developed to determine the optimal design parameters, namely bond size, mirror segment span, and number of layers per meta-shell. The parameters of an example 1.3 m diameter mirror assembly are given including the predicted effective area. To verify the mathematical model and support opto-mechanical analysis, a detailed finite element model of a meta-shell was created. Finite element analysis predicts low gravity distortion and low thermal distortion. Recent results are discussed including Structural Thermal Optical Performance (STOP) analysis as well as vibration and shock testing of prototype meta-shells.

  2. Exploratory X-Ray Monitoring of Luminous Radio-quiet Quasars at High Redshift: No Evidence for Evolution in X-Ray Variability

    Science.gov (United States)

    Shemmer, Ohad; Brandt, W. N.; Paolillo, Maurizio; Kaspi, Shai; Vignali, Cristian; Lira, Paulina; Schneider, Donald P.

    2017-10-01

    We report on the second installment of an X-ray monitoring project of seven luminous radio-quiet quasars (RQQs). New Chandra observations of four of these, at 4.10≤slant z≤slant 4.35, yield a total of six X-ray epochs per source, with temporal baselines of ˜ 850{--}1600 days in the rest frame. These data provide the best X-ray light curves for RQQs at z> 4 to date, enabling qualitative investigations of the X-ray variability behavior of such sources for the first time. On average, these sources follow the trend of decreasing variability amplitude with increasing luminosity, and there is no evidence for X-ray variability increasing toward higher redshifts, in contrast with earlier predictions of potential evolutionary scenarios. An ensemble variability structure function reveals that their variability level remains relatively flat across ≈ 20{--}1000 days in the rest frame and it is generally lower than that of three similarly luminous RQQs at 1.33≤slant z≤slant 2.74 over the same temporal range. We discuss possible explanations for the increased variability of the lower-redshift subsample and, in particular, whether higher accretion rates play a leading role. Near-simultaneous optical monitoring of the sources at 4.10≤slant z≤slant 4.35 indicates that none is variable on ≈ 1 day timescales, although flux variations of up to ˜25% are observed on ≈ 100 day timescales, typical of RQQs at similar redshifts. Significant optical-X-ray spectral slope variations observed in two of these sources are consistent with the levels observed in luminous RQQs and are dominated by X-ray variations.

  3. High time resolution CCD camera with X-ray image intensifier for SPring-8 BL40XU

    CERN Document Server

    Oka, T; Yagi, N

    2003-01-01

    SPring-8 BL40XU is designed to use high flux X-ray for small angle X-ray scattering and multi purpose. The flux at the experimental hutch is about 1 x 10 sup 1 sup 5 photons/sec at 12.4 KeV, which is larger 2 approx 3 figures than other beamlines at SPring-8. To utilize the high flux X-ray efficiently, new high-speed detector is needed. Therefore, a high frame rate CCD camera C7770 (Hamamatsu) and a new 6-inch X-ray image intensifier V5445P (Hamamatsu) were developed for BL40XU. The CCD camera has three CCD chips to increase the readout speed. Three identical images are created by a prism system in the CCD camera and projected onto the three chips. The pixel number of the CCD is 640 x 480 and the frame rate is 291 frames/sec. Reduction of the number of horizontal lines leads to a faster frame rate up to a few thousands. The combination of the CCD and with an X-ray shutter also leads to faster discrete data acquisition. (author)

  4. X-ray phase microtomography with a single grating for high-throughput investigations of biological tissue.

    Science.gov (United States)

    Zdora, Marie-Christine; Vila-Comamala, Joan; Schulz, Georg; Khimchenko, Anna; Hipp, Alexander; Cook, Andrew C; Dilg, Daniel; David, Christian; Grünzweig, Christian; Rau, Christoph; Thibault, Pierre; Zanette, Irene

    2017-02-01

    The high-throughput 3D visualisation of biological specimens is essential for studying diseases and developmental disorders. It requires imaging methods that deliver high-contrast, high-resolution volumetric information at short sample preparation and acquisition times. Here we show that X-ray phase-contrast tomography using a single grating can provide a powerful alternative to commonly employed techniques, such as high-resolution episcopic microscopy (HREM). We present the phase tomography of a mouse embryo in paraffin obtained with an X-ray single-grating interferometer at I13-2 Beamline at Diamond Light Source and discuss the results in comparison with HREM measurements. The excellent contrast and quantitative density information achieved non-destructively and without staining using a simple, robust setup make X-ray single-grating interferometry an optimum candidate for high-throughput imaging of biological specimens as an alternative for existing methods like HREM.

  5. Next Generation X-ray Optics: High Angular Resolution, Light Weight, and Low Production Cost

    Science.gov (United States)

    Zhang, William

    2013-01-01

    Since its beginning 50 years ago, X-ray astronomy has advanced by leaps and bounds, culminating in its current golden age in which three major observatories—Chandra, XMM-Newton, and Suzaku—are operating simultaneously and addressing some of the most important astronomical and astrophysical problems of our time. Building upon this success, the recent Decadal Survey of Astronomy and Astrophysics has defined objectives for x-ray astronomy whose realization requires both new optics and new detector technologies. The development of these technologies has been identified as one of the highest priorities for funding to enable future x-ray missions. X-ray optics technology based on precision glass slumping is on the verge of revolutionizing x-ray telescope making. It has shown that extremely thin (fabricated consistently, efficiently, and inexpensively. In comparison with those of XMM-Newton, these mirror segments represent a factor of 10 reduction in mass while achieving slightly better angular resolution. In comparison with those of Suzaku, they represent a factor of 20 improvement in angular resolution while maintaining the same mass areal density. These advances have been demonstrated with x-ray images from aligned and bonded mirror segments. In short, this technology is approaching TRL-5 for making the mirror assemblies required for a 10 arc-second observatory. In this poster we will present the latest x-ray and environment test results obtained with technology development modules which are substantially similar to flight modules in the way they constructed and tested.

  6. Strength and structural phase transitions of gadolinium at high pressure from radial X-ray diffraction

    Energy Technology Data Exchange (ETDEWEB)

    Xiong, Lun, E-mail: xionglun@ihep.ac.cn; Liu, Jing; Bai, Ligang; Li, Xiaodong; Lin, Chuanlong [Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China); Lin, Jung-Fu [Department of Geological Sciences, Jackson School of Geosciences, The University of Texas at Austin, Texas 78712 (United States)

    2014-12-28

    Lattice strength and structural phase transitions of gadolinium (Gd) were determined under nonhydrostatic compression up to 55 GPa using an angle-dispersive radial x-ray diffraction technique in a diamond-anvil cell at room temperature. Three new phases of fcc structure, dfcc structure, and new monoclinic structure were observed at 25 GPa, 34 GPa, and 53 GPa, respectively. The radial x-ray diffraction data yield a bulk modulus K{sub 0} = 36(1) GPa with its pressure derivate K{sub 0}′ = 3.8(1) at the azimuthal angle between the diamond cell loading axis and the diffraction plane normal and diffraction plane ψ = 54.7°. With K{sub 0}′ fixed at 4, the derived K{sub 0} is 34(1) GPa. In addition, analysis of diffraction data with lattice strain theory indicates that the ratio of differential stress to shear modulus (t/G) ranges from 0.011 to 0.014 at pressures of 12–55 GPa. Together with estimated high-pressure shear moduli, our results show that Gd can support a maximum differential stress of 0.41 GPa, while it starts to yield to plastic deformation at 16 GPa under uniaxial compression. The yield strength of Gd remains approximately a constant with increasing pressure, and reaches 0.46 GPa at 55 GPa.

  7. Internal strains and stresses measured in cortical bone via high-energy x-ray diffraction.

    Energy Technology Data Exchange (ETDEWEB)

    Almer, J. D.; Stock, S. R.; Experimental Facilities Division (APS); Northwestern Univ.,

    2005-01-01

    High-energy synchrotron X-ray diffraction was used to study internal stresses in bone under in situ compressive loading. A transverse cross-section of a 12-14 year old beagle fibula was studied with 80.7 keV radiation, and the transmission geometry was used to quantify internal strains and corresponding stresses in the mineral phase, carbonated hydroxyapatite. The diffraction patterns agreed with tabulated patterns, and the distribution of diffracted intensity around 00.2/00.4 and 22.2 diffraction rings was consistent with the imperfect 00.1 fiber texture expected along the axis of a long bone. Residual compressive stress along the bone's longitudinal axis was observed in the specimen prior to testing: for 22.2 this stress equaled -95 MPa and for 00.2/00.4 was between -160 and -240 MPa. Diffraction patterns were collected for applied compressive stresses up to -110 MPa, and, up to about -100 MPa, internal stresses rose proportionally with applied stress but at a higher rate, corresponding to stress concentration in the mineral of 2.8 times the stress applied. The widths of the 00.2 and 00.4 diffraction peaks indicated that crystallite size perpendicular to the 00.1 planes increased from t = 41 nm before stress was applied to t = 44 nm at -118 MPa applied stress and that rms strain {var_epsilon}{sub rms} rose from 2200 {mu}{var_epsilon} before loading to 4600 {mu}{var_epsilon} at the maximum applied stress. Small angle X-ray scattering of the unloaded sample, recorded after deformation was complete, showed a collagen D-period of 66.4 nm (along the bone axis).

  8. Alignment, Assembly and Testing of High Energy X-Ray Optics

    Science.gov (United States)

    Gubarev, Mikhail; Ramsey, Brian

    2005-01-01

    We are developing grazing-incidence x-ray imaging optics for a balloon-borne hard x-ray telescope (HERO). The HERO payload, scheduled for launch in May 2005, currently consists of 8 mirror modules each containing 12 mirror shells fabricated using electroform-nickel replication off super-polished cylindrical mandrels. An optical system developed for aligning and assembling the shells in the modules will be described. Sources for systematic errors associated with this process will be discussed and results from on-ground x-ray testing of each module will be presented.

  9. Characterization of high intensity Ni-like X-ray lasers and their application experiment

    Energy Technology Data Exchange (ETDEWEB)

    Tang, H.J.; Daido, H.; Suzuki, M. [Osaka Univ., Suita (Japan). Inst. of Laser Engineering; Japan Atomic Energy Research Inst., Kyoto (Japan). Advanced Photon Research Center; Yamagami, S.; Nagai, K.; Norimatsu, T.; Mima, K.; Yamanaka, T. [Osaka Univ., Suita (Japan). Inst. of Laser Engineering; Kato, Y.; Sasaki, A.; Hasegawa, N. [Japan Atomic Energy Research Inst., Kyoto (Japan). Advanced Photon Research Center; Wang, S.; Gu, Y.; Huang, G. [National Lab. on High Power Laser and Physics, Shanghai, SH (China); Carillon, A.; Ros, D.; Fourcade, P.; Jamelot, G. [Lab. de Spectroscopie Atomique et Ionique, Univ. Paris-Sud, Orsay (France); Joyeux, D.; Phalippou, D. [Lab. Charles Fabry, CNRS, Inst. d' Optique, Orsay (France); Murai, K. [Osaka National Research Inst., Ikeda, Osaka (Japan); Butzbach, R.; Uschmann, I.; Foerster, E. [IOQ, Friedrich-Schiller Univ., Jena (Germany); Namikawa, K.; Tai, R. [Tokyo Gakugei Univ., Koganei (Japan); Koike, F. [Kitasato Univ., Sagamihara, Kanagawa (Japan). School of Medicine; Takenaka, H. [NTT Advanced Technology, Musashino (Japan); Zhang, G. [Inst. of Applied Physics and Computational Mathematics, Beijing, BJ (China); Choi, I.W. [Korea Advanced Inst. of Science and Technology, Taejon (Korea)

    2001-07-01

    At the Institute of Laser Engineering, Osaka University, we have obtained Ni-like X-ray lasers of various atomic number elements, including many shorter wavelength Ni-like lasing lines around 5 nm. The saturated amplification of Ni-like Ag lasing line at the wavelength of 13.9 nm have been observed. Using these X-ray lasers, we are preparing the application experiments such as probing a laser-produced plasma with an X-ray laser interferometer. (orig.)

  10. Measurement of the Energy and High-Pressure Dependence of X-ray-Induced Decomposition of Crystalline Strontium Oxalate

    Energy Technology Data Exchange (ETDEWEB)

    Goldberger, David [High-Pressure; Evlyukhin, Egor [High-Pressure; Cifligu, Petrika [High-Pressure; Wang, Yonggang [HPCAT,; Pravica, Michael [High-Pressure

    2017-09-18

    We report measurements of the X-ray-induced decomposition of crystalline strontium oxalate (SrC2O4) as a function of energy and high pressure in two separate experiments. SrC2O4 at ambient conditions was irradiated with monochromatic synchrotron X-rays ranging in energy from 15 to 28 keV. A broad resonance of the decomposition yield was observed with a clear maximum when irradiating with ~20 keV X-rays and ambient pressure. Little or no decomposition was observed at 15 keV, which is below the Sr K-shell energy of 16.12 keV, suggesting that excitation of core electrons may play an important role in the destabilization of the C2O42– anion. A second experiment was performed to investigate the high-pressure dependence of the X-ray-induced decomposition of strontium oxalate at fixed energy. SrC2O4 was compressed in a diamond anvil cell (DAC) in the pressure range from 0 to 7.6 GPa with 1 GPa increments and irradiated in situ with 20 keV X-rays. A marked pressure dependence of the decomposition yield of SrC2O4 was observed with a decomposition yield maximum at around 1 GPa, suggesting that different crystal structures of the material play an important role in the decomposition process. This may be due in part to a phase transition observed near this pressure.

  11. MEASUREMENT OF THE HIGH ENERGY COMPONENT OF THE X-RAY SPECTRA INTHE VENUS ECR ION SOURCE

    Energy Technology Data Exchange (ETDEWEB)

    Leitner, Daniela; Benitez, Janilee Y.; Lyneis, Claude M.; Todd,Damon S.; Ropponen,Tommi; Ropponen,Janne; Koivisto, Hannu; Gammino, Santo

    2007-11-15

    High performance electron cyclotron resonance (ECR) ion sources, such as VENUS (Versatile ECR for Nuclear Science), produce large amounts of x-rays. By studying their energy spectra, conclusions can be drawn about the electron heating process and the electron confinement. In addition, the bremsstrahlung from the plasma chamber is partly absorbed by the cold mass of the superconducting magnet adding an extra heat load to the cryostat. Germanium or NaI detectors are generally used for x-ray measurements. Due to the high x-ray flux from the source, the experimental set-up to measure bremsstrahlung spectra from ECR ion sources is somewhat different than for the traditional nuclear physics measurements these detectors are generally used for. In particular the collimation and background shielding can be problematic. In this paper we will discuss the experimental set-up for such a measurement, the energy calibration and background reduction, the correction for detector efficiency, the shielding of the detector and collimation of the x-ray flux. We will present x-ray energy spectra and cryostat heating rates in dependence of various ion source parameters such as confinement fields, minimum B-field, rf power and heating frequency.

  12. Applying a physical continuum model to describe the broadband X-ray spectra of accreting pulsars at high luminosity

    Science.gov (United States)

    Pottschmidt, Katja; Hemphill, Paul B.; Wolff, Michael T.; Cheatham, Diana M.; Iwakiri, Wataru; Gottlieb, Amy M.; Falkner, Sebastian; Ballhausen, Ralf; Fuerst, Felix; Kuehnel, Matthias; Ferrigno, Carlo; Becker, Peter A.; Wood, Kent S.; Wilms, Joern

    2018-01-01

    A new window for better understanding the accretion onto strongly magnetized neutron stars in X-ray binaries is opening. In these systems the accreted material follows the magnetic field lines as it approaches the neutron star, forming accretion columns above the magnetic poles. The plasma falls toward the neutron star surface at near-relativistic speeds, losing energy by emitting X-rays. The X-ray spectral continua are commonly described using phenomenological models, i.e., power laws with different types of curved cut-offs at higher energies. Here we consider high luminosity pulsars. In these systems the mass transfer rate is high enough that the accreting plasma is thought to be decelerated in a radiation-dominated radiative shock in the accretion columns. While the theory of the emission from such shocks had already been developed by 2007, a model for direct comparison with X-ray continuum spectra in xspec or isis has only recently become available. Characteristic parameters of this model are the accretion column radius and the plasma temperature, among others. Here we analyze the broadband X-ray spectra of the accreting pulsars Centaurus X-3 and 4U 1626-67 obtained with NuSTAR. We present results from traditional empirical modeling as well as successfully apply the radiation-dominated radiative shock model. We also take the opportunity to compare to similar recent analyses of both sources using these and other observations.

  13. A rotational and axial motion system load frame insert for in situ high energy x-ray studies

    Energy Technology Data Exchange (ETDEWEB)

    Shade, Paul A., E-mail: paul.shade.1@us.af.mil; Schuren, Jay C.; Turner, Todd J. [Materials and Manufacturing Directorate, Air Force Research Laboratory, Wright-Patterson AFB, Ohio 45433 (United States); Blank, Basil [PulseRay, Beaver Dams, New York 14812 (United States); Kenesei, Peter; Goetze, Kurt; Lienert, Ulrich; Almer, Jonathan [Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Suter, Robert M. [Carnegie Mellon University, Pittsburgh, Pennsylvania 15213 (United States); Bernier, Joel V.; Li, Shiu Fai [Engineering Directorate, Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Lind, Jonathan [Carnegie Mellon University, Pittsburgh, Pennsylvania 15213 (United States); Engineering Directorate, Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)

    2015-09-15

    High energy x-ray characterization methods hold great potential for gaining insight into the behavior of materials and providing comparison datasets for the validation and development of mesoscale modeling tools. A suite of techniques have been developed by the x-ray community for characterizing the 3D structure and micromechanical state of polycrystalline materials; however, combining these techniques with in situ mechanical testing under well characterized and controlled boundary conditions has been challenging due to experimental design requirements, which demand new high-precision hardware as well as access to high-energy x-ray beamlines. We describe the design and performance of a load frame insert with a rotational and axial motion system that has been developed to meet these requirements. An example dataset from a deforming titanium alloy demonstrates the new capability.

  14. Highly perfect thin films of SiC: X-ray double crystal diffractometry and X-ray double crystal topographic study

    Energy Technology Data Exchange (ETDEWEB)

    Chaudhuri, J.; Cheng, X. [Wichita State Univ., KS (United States). Dept. of Mechanical Engineering; Yuan, C. [Emcore Corp., Somerset, NJ 08873 (United States); Steckl, A.J. [Nanoelectronics Laboratory, Department of Electrical and Computer Engineering, University of Cincinnati, Cincinnati, OH 45221-0030 (United States)

    1997-01-05

    The structure, strain and defect density of SiC thin films epitaxially deposited on 6H-SiC (0001), Si(111) and Si(001) from the single-source organosilane precursor silacyclobutane (c-C{sub 3}H{sub 6}SiH{sub 2}) were determined by X-ray double crystal diffractometry and topographic methods. All the films grown on Si were found to be 3C-SiC type. The films grown on 6H-SiC (0001) at 800 to 1000 C were found to be 3C-SiC type, whereas the films grown on 6H-SiC (0001) at 1100 C were a mixture of 3C, 4H and 6H polytypes of SiC. All the films grown on Si had very high defect densities. However, the defect density was reduced by a factor of 10{sup 4} for the films of similar thickness on 6H-SiC (0001), with the film grown at 900 C being the optimum one exhibiting structural properties nearly equal to those of the substrate. (orig.) 35 refs.

  15. Frontiers in x-ray components for high-resolution spectroscopy and imaging laminar type varied-line-spacing holographic gratings for soft x-ray

    CERN Document Server

    Sano, K

    2003-01-01

    Laminar-type varied-line-spacing gratings have been widely used for soft x-ray monochromator recently because of the features of low stray lights and higher order lights. We have developed and advanced holographic recording and an ion-beam etching methods for the laminar type varied-line spacing gratings. This report describes a short review of the soft x-ray spectrometers using varied-line-spacing gratings, the fabrication process of the laminar-type holographic gratings, and the performance of the flat field spectrographs equipped with the laminar type varied-line spacing gratings comparing with the mechanically ruled replica gratings. It is concluded that, for the sake of the advanced design and fabrication processes and excellent spectroscopic performance, laminar-type holographic gratings will be widely used for soft x-ray spectrometers for various purposes in the near future. (author)

  16. Toward a practical X-ray Fourier holography at high resolution

    CERN Document Server

    Howells, M R; Marchesini, S; Miller, S; Spence, J C H; Weirstall, U

    2001-01-01

    We consider the theory and data analysis in Fourier-transform X-ray holography. We also report studies and experimental investigations of practical ways to generate a suitable holographic reference wave.

  17. Deterministic Computer-Controlled Polishing Process for High-Energy X-Ray Optics

    Science.gov (United States)

    Khan, Gufran S.; Gubarev, Mikhail; Speegle, Chet; Ramsey, Brian

    2010-01-01

    A deterministic computer-controlled polishing process for large X-ray mirror mandrels is presented. Using tool s influence function and material removal rate extracted from polishing experiments, design considerations of polishing laps and optimized operating parameters are discussed

  18. Fabrication of High Resolution Lightweight X-ray Mirrors Using Mono-crystalline Silicon Project

    Data.gov (United States)

    National Aeronautics and Space Administration — "Three factors characterize an X-ray optics fabrication technology: angular resolution, effective area per unit mass, and production cost per unit effective...

  19. High-resolution x-ray characterization of mosaic crystals for hard x-and gamma-ray astronomy

    Science.gov (United States)

    Ferrari, Claudio; Buffagni, Elisa; Marchini, Laura; Zappettini, Andrea

    2011-09-01

    We have analyzed GaAs, Cu, CdTe, and CdZnTe crystals as possible optical elements for hard x-ray lenses for x-ray astronomy. We used high resolution x-ray diffraction at 8keV in Bragg geometry and Laue transmission diffraction at synchrotron at energies up to 500 keV. A good agreement was found between the mosaicity evaluated in Bragg diffraction geometry with x-ray penetration of the order of few tens micrometers and in Laue transmission geometry at synchrotron. All the analyzed crystals showed mosaicity values in a range between a few to 150 arcseconds and suitable for the application. Nevertheless -CdTe and CdZnTe crystals exhibit non-uniformity due to the presence of low angle grain boundaries; -Cu crystals exhibit mosaicity of the order of several arcminutes; they indeed suffer by a severe cutting damage that had to be removed with a very deep etching. The FWHM was also rapidly decreasing with the x-ray energy showing that the mosaic spread is not the only origin of peak broadening; -GaAs crystals grown by Czochralski method show mosaicity up to 30 arcseconds and good diffraction efficiency up to energies of 500 keV. The use of thermal treatments as a possible method to increase the mosaic spread is also evaluated.

  20. Measurement of the Hg distribution in a high-pressure arc lamp by x-ray absorption

    Science.gov (United States)

    Curry, J. J.; Sakai, M.; Lawler, J. E.

    1998-09-01

    We have used an x-ray absorption technique to measure the distribution of Hg atoms in a pure-Hg high-pressure arc lamp. The x rays are obtained from a molybdenum-anode x-ray tube at an accelerating potential of 25.3 kV. The spectral distribution of x rays which produce the absorption signal consists mainly of the Mo Kα and Kβ fluorescence peaks at 17.5 and 19.6 keV, respectively. Plane-wave illumination of the lamp and two-dimensional detection of the transmitted x rays allow us to probe the Hg atom density in all regions of the lamp, simultaneously, with a spatial resolution of 170 μm. A complete two-dimensional map of the density is obtained by Abel inversion of the absorption data. This map extends all the way out to the arc-envelope boundary and includes the cold regions of the discharge behind the electrodes. A temperature map of the discharge is obtained by combining the density information with an optical emission measurement of the core temperature at a single axial location.

  1. Development of high spatial resolution X-ray CT system at BL47XU in SPring-8

    CERN Document Server

    Uesugi, K; Yagi, N; Tsuchiyama, A; Nakano, T

    2001-01-01

    High spatial resolution, micrometer range, X-ray CT system has been developed at SPring-8. The experiments were performed at the undulator beam line BL47XU. An 'in-vacuum type' undulator is employed as an X-ray source, and the X-rays are monochromatized with a liquid nitrogen cooled Si(1 1 1) double crystal monochromator. High precision rotation stage with air bearing was used for sample rotation. The transmitted images were obtained with a two-dimensional image detector, which consists of a single crystal phosphor screen (Lu sub 2 SiO sub 5 : Ce), an objective lens and a cooled CCD camera. In this system the smallest effective pixel size was set to 0.5 mu mx0.5 mu m. As a result of the experiments, three-dimensional images of a few micrometer-order texture has been successfully obtained with the developed CT system.

  2. High-resolution hard x-ray spectroscopy of high-temperature plasmas using an array of quantum microcalorimeters.

    Science.gov (United States)

    Thorn, Daniel B; Gu, Ming F; Brown, Greg V; Beiersdorfer, Peter; Porter, F Scott; Kilbourne, Caroline A; Kelley, Richard L

    2008-10-01

    Quantum microcalorimeters show promise in being able to fully resolve x-ray spectra from heavy highly charged ions, such as would be found in hot plasmas with temperatures in excess of 50 keV. Quantum microcalorimeter arrays are able to achieve this as they have a high-resolving power and good effective quantum efficiency for hard x-ray photons up to 60 keV. To demonstrate this, we present a measurement using an array of thin HgTe quantum microcalorimeters to measure the K-shell spectrum of hydrogenlike through carbonlike praseodymium (Z=57). With this device we are able to attain a resolving power, E/DeltaE, of 1000 at a photon energy of 37 keV.

  3. A large-volume gas cell for high-energy X-ray reflectivity investigations of interfaces under pressure.

    Science.gov (United States)

    Venturini, Federica; Schöder, Sebastian; Kuhs, Werner F; Honkimäki, Veijo; Melesi, Louis; Reichert, Harald; Schober, Helmut; Thomas, Frederic

    2011-03-01

    A cell for the investigation of interfaces under pressure is presented. Given the pressure and temperature specifications of the cell, P ≤ 100 bar and 253 K ≤ T ≤ 323 K, respectively, high-energy X-rays are required to penetrate the thick Al(2)O(3) windows. The CH(4)(gas)/H(2)O(liquid) interface has been chosen to test the performance of the new device. The measured dynamic range of the high-energy X-ray reflectivity data exceeds 10(-8), thereby demonstrating the validity of the entire experimental set-up.

  4. The super-orbital modulation of supergiant high-mass X-ray binaries

    Science.gov (United States)

    Bozzo, E.; Oskinova, L.; Lobel, A.; Hamann, W.-R.

    2017-10-01

    The long-term X-ray light curves of classical supergiant X-ray binaries and supergiant fast X-ray transients show relatively similar super-orbital modulations, which are still lacking a sound interpretation. We propose that these modulations are related to the presence of corotating interaction regions (CIRs) known to thread the winds of OB supergiants. To test this hypothesis, we couple the outcomes of three-dimensional (3D) hydrodynamic models for the formation of CIRs in stellar winds with a simplified recipe for the accretion onto a neutron star. The results show that the synthetic X-ray light curves are indeed modulated by the presence of the CIRs. The exact period and amplitude of these modulations depend on a number of parameters governing the hydrodynamic wind models and on the binary orbital configuration. To compare our model predictions with the observations, we apply the 3D wind structure previously shown to well explain the appearance of discrete absorption components in the UV time series of a prototypical B0.5I-type supergiant. Using the orbital parameters of IGRJ 16493-4348, which has the same B0.5I donor spectral type, the period and modulations in the simulated X-ray light curve are similar to the observed ones, thus providing support to our scenario. We propose that the presence of CIRs in donor star winds should be considered in future theoretical and simulation efforts of wind-fed X-ray binaries.

  5. Microstructure of calcite deformed by high-pressure torsion: An X-ray line profile study

    Science.gov (United States)

    Schuster, Roman; Schafler, Erhard; Schell, Norbert; Kunz, Martin; Abart, Rainer

    2017-11-01

    Calcite aggregates were deformed to high strain using high-pressure torsion and applying confining pressures of 1-6 GPa and temperatures between room temperature and 450 °C. The run products were characterized by X-ray diffraction, and key microstructural parameters were extracted employing X-ray line profile analysis. The dominant slip system was determined as r { 10 1 bar 4 } ⟨ 2 bar 021 ⟩ with edge dislocation character. The resulting dislocation density and the size of the coherently scattering domains (CSD) exhibit a systematic dependence on the P-T conditions of deformation. While high pressure generally impedes recovery through reducing point defect mobility, the picture is complicated by pressure-induced phase transformations in the CaCO3 system. Transition from the calcite stability field to those of the high-pressure polymorphs CaCO3-II, CaCO3-III and CaCO3-IIIb leads to a change of the microstructural evolution with deformation. At 450 °C and pressures within the calcite stability field, dislocation densities and CSD sizes saturate at shear strains exceeding 10 in agreement with earlier studies at lower pressures. In the stability field of CaCO3-II, the dislocation density exhibits a more complex behavior. Furthermore, at a given strain and strain rate, the dislocation density increases and the CSD size decreases with increasing pressure within the stability fields of either calcite or of the high-pressure polymorphs. There is, however, a jump from high dislocation densities and small CSDs in the upper pressure region of the calcite stability field to lower dislocation densities and larger CSDs in the low-pressure region of the CaCO3-II stability field. This jump is more pronounced at higher temperatures and less so at room temperature. The pressure influence on the deformation-induced evolution of dislocation densities implies that pressure variations may change the rheology of carbonate rocks. In particular, a weakening is expected to occur at

  6. High resolution tip-tilt positioning system for a next generation MLL-based x-ray microscope

    Science.gov (United States)

    Xu, Weihe; Schlossberger, Noah; Xu, Wei; Yan, Hanfei; Huang, Xiaojing; Chu, Yong S.; Nazaretski, E.

    2017-12-01

    Multilayer Laue lenses (MLLs) are x-ray focusing optics with the potential to focus hard x-rays down to a single nanometer level. In order to achieve point focus, an MLL microscope needs to have the capability to perform tip-tilt motion of MLL optics and to hold the angular position for an extended period of time. In this work, we present a 2D tip-tilt system that can achieve an angular resolution of over 100 microdegree with a working range of 4°, by utilizing a combination of laser interferometer and mini retroreflector. The linear dimensions of the developed system are about 30 mm in all directions, and the thermal dissipation of the system during operation is negligible. Compact design and high angular resolution make the developed system suitable for MLL optics alignment in the next generation of MLL-based x-ray microscopes.

  7. Investigation of high-resolution superconducting tunnel junction detectors for low-energy X-ray fluorescence analysis

    CERN Document Server

    Beckhoff, B; Ulm, G

    2003-01-01

    The energy resolution of conventional semiconductor detectors is insufficient for simultaneously separating the leading fluorescence lines of low Z and medium Z materials in the soft X-ray regime. It is therefore important to investigate alternative detection instruments offering higher energy resolution and evaluate their applicability to soft X-ray fluorescence (XRF) analysis. In this paper, various results of the characterization and evaluation of a cryogenic superconducting tunnel junction (STJ) detector, which was provided to the Physikalisch-Technische Bundesanstalt (PTB) by the Lawrence Livermore National Laboratory, are given with respect to both detector response functions and XRF. For this investigation, monochromatized undulator radiation of high spectral purity, available to the PTB X-ray radiometry laboratory at the electron storage ring BESSY II, was employed, by which it was possible to record the STJ response functions at various photon energies of interest ranging from 180 to 1600 eV. By scan...

  8. Observation of immuno-labeled cells at high resolution using soft X-ray microscope at Ritsumeikan University SR Center

    Energy Technology Data Exchange (ETDEWEB)

    Yamamoto, A [Nagahama Institute of Bio-Science and Technology, 1266, Tamura-cho, Nagahama, Shiga, 526-0829 (Japan); Takemoto, K; Kihara, H [Department of Physics, Kansai Medical University, 18-89 Uyamahigashi, Hirakata, Osaka, 573-1136 (Japan); Fukui, T; Yoshimura, Y; Namba, H [Department of Physical Science, Ritsumeikan University, 1-1-1, Noji-Higashi, Kusatsu, Shiga, 525-8577 (Japan); Okuno, K, E-mail: takemoto@makino.kmu.ac.j [SR Center, Ritsumeikan University, 1-1-1, Noji-Higashi Kusatsu, Shiga, 525-8577 (Japan)

    2009-09-01

    Mouse fibroblast cell line NIH3T3 cells were labeled with the heavy metal (silver and gold) and observed intracellular structure under an X-ray microscope. Microtubules, Golgi apparatus and early endosomes of NIH3T3 cells were stained with immuno-gold nanoparticles, and immuno-staining was intensified by silver or gold enhancement procedure. Using a transmission soft X-ray microscope beamline (BL12) at Ritsumeikan University SR center, we observed immuno-stained NIH3T3 cells with several wavelengths just below and above oxygen edge ({lambda} = 2.32 nm). Using this method, cytoskeleton (microtubules) and organelles (Golgi apparatus and early endosomes) were successfully imaged with high resolution. Thus, immuno-gold silver and gold enhancement technique is useful for specific labeling of intracellular structure under an X-ray microscope.

  9. X-Ray Visualisation Of High Speed Phenomena: Application To The Behavior Of Materials Under High Explosives Loading

    Science.gov (United States)

    Hauducoeur, A.; Fischer, D.; Guix, R.

    1983-08-01

    Flash Radiography and Cineradiography allow the visualisation of high speed phenomena and the stop motion effect with recording on film of qualitative and quantitative data on the dynamic state of the matter under very intense shock waves. In this paper, we present a set of experimental devices and results obtained with a large range of flash X-ray generators : - small generators made with Marx discharge circuits coupled to void X-ray tubes, working up to 2.5 MV, - a big flash machine, GREC (presented at this conference (ref.1))used with very absor-bing materials. The presented applications illustrate a large field of experiments in the field of shock waves, interaction of 2 shock or detonation waves, flow visualisation of detonation, Taylor instabilities/metal jetting, spalling in iron...

  10. Final Report on Developing Microstructure-Property Correlation in Reactor Materials using in situ High-Energy X-rays

    Energy Technology Data Exchange (ETDEWEB)

    Li, Meimei [Argonne National Lab. (ANL), Argonne, IL (United States); Almer, Jonathan D. [Argonne National Lab. (ANL), Argonne, IL (United States); Yang, Yong [Univ. of Florida, Gainesville, FL (United States); Tan, Lizhen [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2016-01-01

    This report provides a summary of research activities on understanding microstructure – property correlation in reactor materials using in situ high-energy X-rays. The report is a Level 2 deliverable in FY16 (M2CA-13-IL-AN_-0403-0111), under the Work Package CA-13-IL-AN_- 0403-01, “Microstructure-Property Correlation in Reactor Materials using in situ High Energy Xrays”, as part of the DOE-NE NEET Program. The objective of this project is to demonstrate the application of in situ high energy X-ray measurements of nuclear reactor materials under thermal-mechanical loading, to understand their microstructure-property relationships. The gained knowledge is expected to enable accurate predictions of mechanical performance of these materials subjected to extreme environments, and to further facilitate development of advanced reactor materials. The report provides detailed description of the in situ X-ray Radiated Materials (iRadMat) apparatus designed to interface with a servo-hydraulic load frame at beamline 1-ID at the Advanced Photon Source. This new capability allows in situ studies of radioactive specimens subject to thermal-mechanical loading using a suite of high-energy X-ray scattering and imaging techniques. We conducted several case studies using the iRadMat to obtain a better understanding of deformation and fracture mechanisms of irradiated materials. In situ X-ray measurements on neutron-irradiated pure metal and model alloy and several representative reactor materials, e.g. pure Fe, Fe-9Cr model alloy, 316 SS, HT-UPS, and duplex cast austenitic stainless steels (CASS) CF-8 were performed under tensile loading at temperatures of 20-400°C in vacuum. A combination of wide-angle X-ray scattering (WAXS), small-angle X-ray scattering (SAXS), and imaging techniques were utilized to interrogate microstructure at different length scales in real time while the specimen was subject to thermal-mechanical loading. In addition, in situ X-ray studies were

  11. Magnetization of Stellar Wind in the High-Mass X-Ray Binary OAO 1657-415

    Science.gov (United States)

    Kim, V. Yu.; Ikhsanov, N. R.

    2017-06-01

    Spin evolution of the X-ray pulsar OAO 1657-415 in a wind-fed High Mass X-ray Binary (HMXB) is discussed. We suggest that its regular spin-up behaviour superposed with the spin-up/down episodes can be explained in terms of the Magnetic Levitation Accretion scenario (MLA scenario). This implies that the neutron star captures matter from a magnetized stellar wind of its massive companion. The magnetic field of the wind at a distance of the orbital separation within this scenario can be limited within the range of 20-70 mG.

  12. High-resolution monochromator using a high-efficiency single-mode x-ray resonator at Laue incidence.

    Science.gov (United States)

    Wu, Yu-Hsin; Tsai, Yi-Wei; Liu, Wen-Chung; Chih, Yu-Chieh; Chang, Shih-Lin

    2017-07-01

    We report a high-resolution and high-efficiency monochromator with energy resolution, ΔE/E∼2.08*10-7, utilizing a hard x-ray single-mode Fabry-Perot (FP) resonator at Laue incidence at 14.4388 keV. Instead of using multiple-crystal diffraction via several asymmetric-cut crystals, a 3 meV single-peak is generated from the interference of a Si-made two-plate cavity with a thickness of 70 μm and a gap of 45 μm, where a (0-40) Laue reflection is used to excite the backreflection (12 4 0) for the enhancement of the FP efficiency. Due to the large angular acceptance of (12 4 0) and (0-40), the energy tunability can be achieved by changing the incident angle into the resonator. The application of x-ray resonators at Laue incidence as a monochromator can be further implemented to x-ray optics.

  13. High-resolution x-ray imaging using a structured scintillator

    Energy Technology Data Exchange (ETDEWEB)

    Hormozan, Yashar, E-mail: hormozan@kth.se; Sychugov, Ilya; Linnros, Jan [Materials and Nano Physics, School of Information and Communication Technology, KTH Royal Institute of Technology, Electrum 229, Kista, Stockholm SE-16440 (Sweden)

    2016-02-15

    Purpose: In this study, the authors introduce a new generation of finely structured scintillators with a very high spatial resolution (a few micrometers) compared to conventional scintillators, yet maintaining a thick absorbing layer for improved detectivity. Methods: Their concept is based on a 2D array of high aspect ratio pores which are fabricated by ICP etching, with spacings (pitches) of a few micrometers, on silicon and oxidation of the pore walls. The pores were subsequently filled by melting of powdered CsI(Tl), as the scintillating agent. In order to couple the secondary emitted photons of the back of the scintillator array to a CCD device, having a larger pixel size than the pore pitch, an open optical microscope with adjustable magnification was designed and implemented. By imaging a sharp edge, the authors were able to calculate the modulation transfer function (MTF) of this finely structured scintillator. Results: The x-ray images of individually resolved pores suggest that they have been almost uniformly filled, and the MTF measurements show the feasibility of a few microns spatial resolution imaging, as set by the scintillator pore size. Compared to existing techniques utilizing CsI needles as a structured scintillator, their results imply an almost sevenfold improvement in resolution. Finally, high resolution images, taken by their detector, are presented. Conclusions: The presented work successfully shows the functionality of their detector concept for high resolution imaging and further fabrication developments are most likely to result in higher quantum efficiencies.

  14. Breast tumor segmentation in high resolution x-ray phase contrast analyzer based computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Brun, E., E-mail: emmanuel.brun@esrf.fr [European Synchrotron Radiation Facility (ESRF), Grenoble 380000, France and Department of Physics, Ludwig-Maximilians University, Garching 85748 (Germany); Grandl, S.; Sztrókay-Gaul, A.; Gasilov, S. [Institute for Clinical Radiology, Ludwig-Maximilians-University Hospital Munich, 81377 Munich (Germany); Barbone, G. [Department of Physics, Harvard University, Cambridge, Massachusetts 02138 (United States); Mittone, A.; Coan, P. [Department of Physics, Ludwig-Maximilians University, Garching 85748, Germany and Institute for Clinical Radiology, Ludwig-Maximilians-University Hospital Munich, 81377 Munich (Germany); Bravin, A. [European Synchrotron Radiation Facility (ESRF), Grenoble 380000 (France)

    2014-11-01

    Purpose: Phase contrast computed tomography has emerged as an imaging method, which is able to outperform present day clinical mammography in breast tumor visualization while maintaining an equivalent average dose. To this day, no segmentation technique takes into account the specificity of the phase contrast signal. In this study, the authors propose a new mathematical framework for human-guided breast tumor segmentation. This method has been applied to high-resolution images of excised human organs, each of several gigabytes. Methods: The authors present a segmentation procedure based on the viscous watershed transform and demonstrate the efficacy of this method on analyzer based phase contrast images. The segmentation of tumors inside two full human breasts is then shown as an example of this procedure’s possible applications. Results: A correct and precise identification of the tumor boundaries was obtained and confirmed by manual contouring performed independently by four experienced radiologists. Conclusions: The authors demonstrate that applying the watershed viscous transform allows them to perform the segmentation of tumors in high-resolution x-ray analyzer based phase contrast breast computed tomography images. Combining the additional information provided by the segmentation procedure with the already high definition of morphological details and tissue boundaries offered by phase contrast imaging techniques, will represent a valuable multistep procedure to be used in future medical diagnostic applications.

  15. X-ray Absorption Spectroscopic Studies of High-Spin Nonheme (Alkylperoxo)iron(III) Intermediates

    Energy Technology Data Exchange (ETDEWEB)

    Shan,X.; Rohde, J.; Koehntop, K.; Zhou, Y.; Bukowski, M.; Costas, M.; Fujisawa, K.; Que, Jr., L.

    2007-01-01

    The reactions of iron(II) complexes [Fe(Tpt-Bu,i-Pr)(OH)] (1a, Tpt-Bu,i-Pr = hydrotris(3-tert-butyl-5-isopropyl-1-pyrazolyl)borate), [Fe(6-Me2BPMCN)(OTf)2] (1b, 6-Me2BPMCN = N,N'-bis((2-methylpyridin-6-yl)methyl)-N,N'-dimethyl-trans-1,2-diaminocyclohexane), and [Fe(L8Py2)(OTf)](OTf) (1c, L8Py2 = 1,5-bis(pyridin-2-ylmethyl)-1,5-diazacyclooctane) with tert-BuOOH give rise to high-spin FeIII-OOR complexes. X-ray absorption spectra (XAS) of these high-spin species show characteristic features, distinct from those of low-spin Fe-OOR complexes. These include (1) an intense 1s {yields} 3d preedge feature, with an area around 20 units, (2) an edge energy, ranging from 7122 to 7126 eV, that is affected by the coordination environment, and (3) a 1.86-1.96 Angstroms Fe-OOR bond, compared to the 1.78 Angstroms Fe-OOR bond in low-spin complexes. These unique features likely arise from a flexible first coordination sphere in those complexes. The difference in Fe-OOR bond length may rationalize differences in reactivity between low-spin and high-spin FeIII-OOR species.

  16. X-ray CT high-density artefact suppression in the presence of bones

    Energy Technology Data Exchange (ETDEWEB)

    Wei Jikun [School of Health Sciences, 550 Stadium Mall Drive, West Lafayette, IN 47907-2051 (United States); Chen Laigao [BioImaging Center of Emphasis, Pfizer Global Research and Development, 2800 Plymouth RD, Ann Arbor, MI 48105 (United States); Sandison, George A [School of Health Sciences, 550 Stadium Mall Drive, West Lafayette, IN 47907-2051 (United States); Liang Yun [Department of Radiology, Indiana University Medical School, Indianapolis, IN 46202 (United States); Xu, Lisa X [School of Mechanical Engineering, 585 Purdue Mall, West Lafayette, IN 47907-2040 (United States)

    2004-12-21

    This paper presents a novel method of reducing x-ray CT high-density artefacts generated by metal objects when abundant bone structures are present in the region of interest. This method has an advantage over previously proposed methods since it heavily suppresses the metal artefacts without introducing extra bone artefacts. The method of suppression requires that bone pixels are isolated and segmented by thresholding. Then artificial CT numbers are assigned to the bone pixels so that their projection profiles are smooth and thus can be properly simulated by a polynomial interpolation. The projection profile of the metal object is then removed to fully suppress the artefacts. The resulting processed profile is fed to a reconstruction routine and the previously preserved bone pixels added back. The new method utilizes two important features of the CT image with metal artefacts: (a) metal and bone pixels are not severely affected by the high-density artefacts and (b) the high-density artefacts can be located in specific projection channels in the profile domain, although they are spread out in the image domain. This suppression method solves the problem of CT image artefacts arising from metal objects in the body. It has the potential to greatly improve diagnostic CT imaging in the presence of these objects and treatment planning that utilizes CT for patients with metal applicators (e.g., brachytherapy for cervix cancer and prostate cryotherapy)

  17. Calibration of a High Resolution X-ray Spectrometer for High-Energy-Density Plasmas on NIF

    Science.gov (United States)

    Kraus, B.; Gao, L.; Hill, K. W.; Bitter, M.; Efthimion, P.; Schneider, M. B.; Chen, H.; Ayers, J.; Beiersdorfer, P.; Liedahl, D.; Macphee, A. G.; Thorn, D. B.; Bettencourt, R.; Kauffman, R.; Le, H.; Nelson, D.

    2017-10-01

    A high-resolution, DIM-based (Diagnostic Instrument Manipulator) x-ray crystal spectrometer has been calibrated for and deployed at the National Ignition Facility (NIF) to diagnose plasma conditions and mix in ignition capsules near stagnation times. Two conical crystals in the Hall geometry focus rays from the Kr He- α, Ly- α, and He- β complexes onto a streak camera for time-resolved spectra, in order to measure electron density and temperature by observing Stark broadening and relative intensities of dielectronic satellites. Signals from these two crystals are correlated with a third crystal that time-integrates the intervening energy range. The spectrometer has been absolutely calibrated using a microfocus x-ray source, an array of CCD and single-photon-counting detectors, and K- and L-absorption edge filters. Measurements of the integrated reflectivity, energy range, and energy resolution for each crystal will be presented. The implications of the calibration on signal levels from NIF implosions and x-ray filter choices will be discussed. This work was performed under the auspices of the U.S. DoE by Princeton Plasma Physics Laboratory under contract DE-AC02-09CH11466 and by Lawrence Livermore National Laboratory under contract DE-AC52-07NA27344.

  18. Charge Summing in Spectroscopic X-Ray Detectors With High-Z Sensors

    CERN Document Server

    Koenig, Thomas; Cecilia, Angelica; Ballabriga, Rafael; Baumbach, Tilo; Llopart, Xavier; Fiederle, Michael; Zuber, Marcus; Hamann, Elias; Fauler, Alex; Campbell, Michael

    2013-01-01

    The spectroscopic performance of photon counting detectors is limited by the effects of charge sharing between neighboring pixels and the emission of characteristic X-rays. For these reasons, an event can be either missed or counted more than once. These effects become more and more of a concern when pixel pitches are reduced, and for the technology available so far, this meant that there would always be a trade-off between a high spatial and a high spectral resolution. In this work, we present first measurements obtained with the new Medipix3RX ASIC, which features a network of charge summing circuits establishing a communication between pixels which helps to mitigate these effects. Combined with cadmium telluride sensors, we show that this new technology is successful at improving a detector's spectroscopic capabilities even at pixel pitches as small as 55 mu m. At this pitch, we measure an energy response function similar to that observed for a pixel pitch of 165 mu m in the absence of a charge summing cir...

  19. High-resolution synchrotron X-ray analysis of bioglass-enriched hydrogels.

    Science.gov (United States)

    Gorodzha, Svetlana; Douglas, Timothy E L; Samal, Sangram K; Detsch, Rainer; Cholewa-Kowalska, Katarzyna; Braeckmans, Kevin; Boccaccini, Aldo R; Skirtach, Andre G; Weinhardt, Venera; Baumbach, Tilo; Surmeneva, Maria A; Surmenev, Roman A

    2016-05-01

    Enrichment of hydrogels with inorganic particles improves their suitability for bone regeneration by enhancing their mechanical properties, mineralizability, and bioactivity as well as adhesion, proliferation, and differentiation of bone-forming cells, while maintaining injectability. Low aggregation and homogeneous distribution maximize particle surface area, promoting mineralization, cell-particle interactions, and homogenous tissue regeneration. Hence, determination of the size and distribution of particles/particle agglomerates in the hydrogel is desirable. Commonly used techniques have drawbacks. High-resolution techniques (e.g., SEM) require drying. Distribution in the dry state is not representative of the wet state. Techniques in the wet state (histology, µCT) are of lower resolution. Here, self-gelling, injectable composites of Gellan Gum (GG) hydrogel and two different types of sol-gel-derived bioactive glass (bioglass) particles were analyzed in the wet state using Synchrotron X-ray radiation, enabling high-resolution determination of particle size and spatial distribution. The lower detection limit volume was 9 × 10(-5) mm(3) . Bioglass particle suspensions were also studied using zeta potential measurements and Coulter analysis. Aggregation of bioglass particles in the GG hydrogels occurred and aggregate distribution was inhomogeneous. Bioglass promoted attachment of rat mesenchymal stem cells (rMSC) and mineralization. © 2016 Wiley Periodicals, Inc.

  20. Preparation of bent crystals as high-efficiency optical elements for hard x-ray astronomy

    Science.gov (United States)

    Buffagni, Elisa; Ferrari, Claudio; Rossi, Francesca; Marchini, Laura; Zappettini, Andrea

    2012-05-01

    Curved crystals, instead of flat mosaic crystals, can be used as optical elements of a Laue lens for hard x- and gamma-ray astronomy to increase the diffraction efficiency. We propose to achieve the bending of the crystals by a controlled surface damaging, which introduces defects in a layer of few tens nanometers in thickness undergoing a highly compressive strain. Several oriented silicon and gallium arsenide wafer crystals have been treated. The local and mean curvature radii of each sample have been determined by means of high resolution x-ray diffraction measurements in Bragg condition at low energy (8 keV). Silicon samples showed spherical curvatures, whereas GaAs-treated samples evidenced elliptical curvatures with major axes corresponding to the crystallographic directions. Curvature radii between 3 and 70 m were easily obtained in wafers of different thicknesses. The characterization of GaAs samples performed in Laue geometry at gamma-ray energy of 120 keV confirmed the increase of the diffraction efficiency in the bent crystals.

  1. The Formation of Rapidly Rotating Black Holes in High-mass X-Ray Binaries

    Science.gov (United States)

    Batta, Aldo; Ramirez-Ruiz, Enrico; Fryer, Chris

    2017-09-01

    High-mass X-ray binaries (HMXRBs), such as Cygnus X-1, host some of the most rapidly spinning black holes (BHs) known to date, reaching spin parameters a≳ 0.84. However, there are several effects that can severely limit the maximum BH spin parameter that could be obtained from direct collapse, such as tidal synchronization, magnetic core-envelope coupling, and mass loss. Here, we propose an alternative scenario where the BH is produced by a failed supernova (SN) explosion that is unable to unbind the stellar progenitor. A large amount of fallback material ensues, whose interaction with the secondary naturally increases its overall angular momentum content, and therefore the spin of the BH when accreted. Through SPH hydrodynamic simulations, we studied the unsuccessful explosion of an 8 {M}⊙ pre-SN star in a close binary with a 12 {M}⊙ companion with an orbital period of ≈1.2 days, finding that it is possible to obtain a BH with a high spin parameter a≳ 0.8 even when the expected spin parameter from direct collapse is a≲ 0.3. This scenario also naturally explains the atmospheric metal pollution observed in HMXRB stellar companions.

  2. High-pressure X-ray and Raman study of a ferrian magnesian spodumene

    Science.gov (United States)

    Gatta, G. Diego; Ballaran, Tiziana Boffa; Iezzi, Gianluca

    2005-06-01

    The high-pressure behaviour of a synthetic P21/c ferrian magnesian spodumene, M2 (Li0.85Mg0.09Fe2+ 0.06)M1(Fe3+ 0.85Mg0.15)Si2O6, has been investigated using in situ single-crystal X-ray diffraction and Raman spectroscopy. No phase transition has been observed within the pressure range investigated. The isothermal equation of state up to 7 GPa was determined. V0, KT0 and K’, simultaneously refined with a Murnaghan equation of state, are: V0= 415.66(7) Å3, KT0=83(1) GPa and K’=9.6(6). The magnitudes of the principal unit-strain coefficients were calculated and their ratios ɛ1:ɛ2:ɛ3=1.00:1.85:2.81 at P=6.83 GPa indicate a very strong anisotropy. Monitoring of the intensity of b-type reflections (h+k= 2n+1) confirms that from room conditions up to 7 GPa the primitive lattice is maintained. Raman spectra have been collected up to 7.4 GPa. No change in the number of observed vibrational modes occurs in the pressure range investigated. At high frequency, the Raman doublet relative to the Si O Si vibrations of the two distinct tetrahedral chains is a broad band at room pressure, however, the frequency difference between the two modes increases with increasing pressure.

  3. High-performance direct conversion X-ray detectors based on sintered hybrid lead triiodide perovskite wafers

    Science.gov (United States)

    Shrestha, Shreetu; Fischer, René; Matt, Gebhard J.; Feldner, Patrick; Michel, Thilo; Osvet, Andres; Levchuk, Ievgen; Merle, Benoit; Golkar, Saeedeh; Chen, Haiwei; Tedde, Sandro F.; Schmidt, Oliver; Hock, Rainer; Rührig, Manfred; Göken, Mathias; Heiss, Wolfgang; Anton, Gisela; Brabec, Christoph J.

    2017-07-01

    Lead halide perovskite semiconductors are in general known to have an inherently high X-ray absorption cross-section and a significantly higher carrier mobility than any other low-temperature solution-processed semiconductor. So far, the processing of several-hundred-micrometres-thick high-quality crystalline perovskite films over a large area has been unresolved for efficient X-ray detection. In this Article, we present a mechanical sintering process to fabricate polycrystalline methyl ammonium lead triiodide perovskite (MAPbI3) wafers with millimetre thickness and well-defined crystallinity. Benchmarking of the MAPbI3 wafers against state-of-the-art CdTe detectors reveals competitive conversion efficiencies of 2,527 µC Gyair-1 cm-2 under 70 kVp X-ray exposure. The high ambipolar mobility-lifetime product of 2 × 10-4 cm2 V-1 is suggested to be responsible for this exceptionally high sensitivity. Our findings inform a new generation of highly efficient and low-cost X-ray detectors based on perovskite wafers.

  4. 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.

  5. Non-destructive quantification of cereal roots in soil using high-resolution X-ray tomography.

    Science.gov (United States)

    Flavel, Richard J; Guppy, Christopher N; Tighe, Matthew; Watt, Michelle; McNeill, Ann; Young, Iain M

    2012-04-01

    One key constraint to further understanding plant root development is the inability to observe root growth in situ due to the opaque nature of soil. Of the present non-destructive techniques, computed tomography (CT) is best able to capture the complexities of the edaphic environment. This study compared the accuracy and impact of X-ray CT measurement of in situ root systems with standard technology (soil core washing and WinRhizo analysis) in the context of treatments that differed in the vertical placement of phosphorus fertilizers within the soil profile. Although root lengths quantified using WinRhizo were 8% higher than that observed in the same plants using CT, measurements of root length by the two methodologies were highly correlated. Comparison of scanned and unscanned plants revealed no effect of repeated scanning on plant growth and CT was not able to detect any changes in roots between phosphorus treatments that was observed using WinRhizo. Overall, the CT technique was found to be fast, safe, and able to detect roots at high spatial resolutions. The potential drawbacks of CT relate to the software to digitally segment roots from soil and air, which will improve significantly as automated segmentation algorithms are developed. The combination of very fast scans and automated segmentation will allow CT methodology to realize its potential as a high-throughput technique for the quantification of roots in soils.

  6. Stability of dislocation structures in copper towards stress relaxation investigated by high angular resolution 3D X-ray diffraction

    DEFF Research Database (Denmark)

    Jakobsen, Bo; Poulsen, Henning Friis; Lienert, Ulrich

    2009-01-01

    A 300 µm thick tensile specimen of OFHC copper is subjected to a tensile loading sequence and deformed to a maximal strain of 3.11%. Using the novel three-dimensional X-ray diffraction method High angular resolution 3DXRD', the evolution of the microstructure within a deeply embedded grain is cha...

  7. Some Aspects of Crystal Centering During X-ray High-throughput Protein Crystallography Experiment

    Science.gov (United States)

    Gaponov, Yu. A.; Matsugaki, N.; Sasajima, K.; Igarashi, N.; Wakatsuki, S.

    A set of algorithms and procedures of a crystal loop centering during X-ray high-throughput protein crystallography experiment has been designed and developed. A simple algorithm of the crystal loop detection and preliminary recognition has been designed and developed. The crystal loop detection algorithm is based on finding out the crystal loop ending point (opposite to the crystal loop pin) using image cross section (digital image column) profile analysis. The crystal loop preliminary recognition procedure is based on finding out the crystal loop sizes and position using image cross section profile analysis. The crystal loop fine recognition procedure based on Hooke-Jeeves pattern search method with an ellipse as a fitting pattern has been designed and developed. The procedure of restoring missing coordinate of the crystal loop is described. Based on developed algorithms and procedures the optimal auto-centering procedure has been designed and developed. A procedure of optimal manual crystal centering (Two Clicks Procedure) has been designed and developed. Developed procedures have been integrated into control software system PCCS installed at crystallography beamlines Photon Factory BL5A and PF-AR NW12, KEK.

  8. In-situ characterization of highly reversible phase transformation by synchrotron X-ray Laue microdiffraction

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Xian [Department of Mechanical and Aerospace Engineering, Hong Kong University of Science and Technology, Clear Water Bay (Hong Kong); Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Tamura, Nobumichi; MacDowell, Alastair [Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); James, Richard D. [Department of Aerospace Engineering and Mechanics, University of Minnesota, Minneapolis, Minnesota 55455 (United States)

    2016-05-23

    The alloy Cu{sub 25}Au{sub 30}Zn{sub 45} undergoes a huge first-order phase transformation (6% strain) and shows a high reversibility under thermal cycling and an unusual martensitc microstructure in sharp contrast to its nearby compositions. This alloy was discovered by systematically tuning the composition so that its lattice parameters satisfy the cofactor conditions (i.e., the kinematic conditions of compatibility between phases). It was conjectured that satisfaction of these conditions is responsible for the enhanced reversibility as well as the observed unusual fluid-like microstructure during transformation, but so far, there has been no direct evidence confirming that these observed microstructures are those predicted by the cofactor conditions. To verify this hypothesis, we use synchrotron X-ray Laue microdiffraction to measure the orientations and structural parameters of variants and phases near the austenite/martensite interface. The areas consisting of both austenite and multi-variants of martensite are scanned by microLaue diffraction. The cofactor conditions have been examined from the kinematic relation of lattice vectors across the interface. The continuity condition of the interface is precisely verified from the correspondent lattice vectors between two phases.

  9. Upgrades of the high resolution imaging x-ray crystal spectrometers on experimental advanced superconducting tokamaka)

    Science.gov (United States)

    Lu, B.; Wang, F.; Shi, Y.; Bitter, M.; Hill, K. W.; Lee, S. G.; Fu, J.; Li, Y.; Wan, B.

    2012-10-01

    Two imaging x-ray crystal spectrometers, the so-called "poloidal" and "tangential" spectrometers, were recently implemented on experimental advanced superconducting tokamak (EAST) to provide spatially and temporally resolved impurity ion temperature (Ti), electron temperature (Te) and rotation velocity profiles. They are derived from Doppler width of W line for Ti, the intensity ratio of Li-like satellites to W line for Te, and Doppler shift of W line for rotation. Each spectrometer originally consisted of a spherically curved crystal and a two-dimensional multi-wire proportional counter (MWPC) detector. Both spectrometers have now been upgraded. The layout of the tangential spectrometer was modified, since it had to be moved to a different port, and the spectrometer was equipped with two high count rate Pilatus detectors (Model 100 K) to overcome the count rate limitation of the MWPC and to improve its time resolution. The poloidal spectrometer was equipped with two spherically bent crystals to record the spectra of He-like and H-like argon simultaneously and side by side on the original MWPC. These upgrades are described, and new results from the latest EAST experimental campaign are presented.

  10. Upgrades of the high resolution imaging x-ray crystal spectrometers on experimental advanced superconducting tokamak.

    Science.gov (United States)

    Lu, B; Wang, F; Shi, Y; Bitter, M; Hill, K W; Lee, S G; Fu, J; Li, Y; Wan, B

    2012-10-01

    Two imaging x-ray crystal spectrometers, the so-called "poloidal" and "tangential" spectrometers, were recently implemented on experimental advanced superconducting tokamak (EAST) to provide spatially and temporally resolved impurity ion temperature (T(i)), electron temperature (T(e)) and rotation velocity profiles. They are derived from Doppler width of W line for Ti, the intensity ratio of Li-like satellites to W line for Te, and Doppler shift of W line for rotation. Each spectrometer originally consisted of a spherically curved crystal and a two-dimensional multi-wire proportional counter (MWPC) detector. Both spectrometers have now been upgraded. The layout of the tangential spectrometer was modified, since it had to be moved to a different port, and the spectrometer was equipped with two high count rate Pilatus detectors (Model 100 K) to overcome the count rate limitation of the MWPC and to improve its time resolution. The poloidal spectrometer was equipped with two spherically bent crystals to record the spectra of He-like and H-like argon simultaneously and side by side on the original MWPC. These upgrades are described, and new results from the latest EAST experimental campaign are presented.

  11. X-ray quantitative analysis on spallation response in high purity copper under sweeping detonation

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Yang, E-mail: yangyanggroup@163.com [School of Material Science and Engineering, Central South University, Changsha 410083 (China); Institute of Fluid Physics, China Academy of Engineering Physics, Mianyang 621900 (China); National Key Laboratory of Explosion Science and Technology, Beijing Institute of Technology, Beijing 100081 (China); Key Laboratory of Nonferrous Metals Material Science and Engineering of Ministry of Education, Central South University, Changsha 410083 (China); Chen, Jixiong; Peng, Zhiqiang [School of Material Science and Engineering, Central South University, Changsha 410083 (China); Guo, Zhaoliang; Tang, Tiegang; Hu, Haibo [Institute of Fluid Physics, China Academy of Engineering Physics, Mianyang 621900 (China); Hu, Yanan [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800 (China)

    2016-06-14

    The 3-D quantitative investigation of spall behavior in high purity copper plants with different heat treatment histories was characterized using X-ray computer tomography (XRCT). The effect of shock stress and grain size on the spatial distribution and morphology of incipient spall samples were discussed. The results revealed that, in samples with similar microstructure, the ranges of void distribution decrease with the increasing of shock stress. The characteristic parameters (such as mean elongation, mean flatness and mean sphericity of voids) determined using XRCT herein as a function of shock stress and grain size. The quantitative analyses of spallation datasets render functional relationships between the microscopic parameters (like volume, frequency) of spallation voids and the microstructure. The XRCT observations show that voids are prone to coalescence in thermo-mechanical treatments (TMT) sample, while the final maximum and mean volume of void were smaller than that of annealed sample. This is due to the smaller grain size of TMT sample, which means more nucleation sites of voids, this made the voids get closer and easier to coalescence, and flat voids formed ultimately.

  12. High-precision measurement of the x-ray Cu Kα spectrum

    Science.gov (United States)

    Mendenhall, Marcus H.; Henins, Albert; Hudson, Lawrence T.; Szabo, Csilla I.; Windover, Donald; Cline, James P.

    2017-06-01

    The structure of the x-ray emission lines of the Cu {{K}}{α } complex has been remeasured on a newly commissioned instrument, in a manner directly traceable to the Système Internationale definition of the meter. In this measurement, the region from 8000 to 8100 eV has been covered with a highly precise angular scale, and well-defined system efficiency, providing accurate wavelengths and relative intensities. This measurement updates the standard multi-Lorentzian-fit parameters from Härtwig, Hölzer, et al, and is in modest disagreement with their results for the wavelength of the {{K}}{α }1 line when compared via quadratic fitting of the peak top; the intensity ratio of {{K}}{α }1 to {{K}}{α }2 agrees within the combined error bounds. However, the position of the fitted top of {{K}}{α }1 is very sensitive to the fit parameters, so it is not believed to be a robust value to quote without further qualification. We also provide accurate intensity and wavelength information for the so-called {{K}}{α }{3,4} ‘satellite’ complex. Supplementary data, available online at stacks.iop.org/JPB/50/115004/mmedia, is provided which gives the entire shape of the spectrum in this region, allowing it to be used directly in cases where simplified, multi-Lorentzian fits to it are not sufficiently accurate.

  13. Correlation of Thermally Induced Pores with Microstructural Features Using High Energy X-rays

    Energy Technology Data Exchange (ETDEWEB)

    Menasche, David B.; Shade, Paul A.; Lind, Jonathan F.; Li, Shiu Fai; Kenesei, Peter; Schuren, Jay C.; Suter, Robert M.

    2016-11-01

    Combined application of a near-field High Energy Diffraction Microscopy measurement of crystal lattice orientation fields and a tomographic measurement of pore distributions in a sintered nickel-based superalloy sample allows pore locations to be correlated with microstructural features. Measurements were carried out at the Advanced Photon Source beamline 1-ID using an X-ray energy of 65 keV for each of the measurement modes. The nickel superalloy sample was prepared in such a way as to generate significant thermally induced porosity. A three-dimensionally resolved orientation map is directly overlaid with the tomographically determined pore map through a careful registration procedure. The data are shown to reliably reproduce the expected correlations between specific microstructural features (triple lines and quadruple nodes) and pore positions. With the statistics afforded by the 3D data set, we conclude that within statistical limits, pore formation does not depend on the relative orientations of the grains. The experimental procedures and analysis tools illustrated are being applied to a variety of materials problems in which local heterogeneities can affect materials properties.

  14. Ultra-high resolution water window x ray microscope optics design and analysis

    Science.gov (United States)

    Shealy, David L.; Wang, C.

    1993-01-01

    This project has been focused on the design and analysis of an ultra-high resolution water window soft-x-ray microscope. These activities have been accomplished by completing two tasks contained in the statement of work of this contract. The new results from this work confirm: (1) that in order to achieve resolutions greater than three times the wavelength of the incident radiation, it will be necessary to use spherical mirror surfaces and to use graded multilayer coatings on the secondary in order to accommodate the large variations of the angle of incidence over the secondary when operating the microscope at numerical apertures of 0.35 or greater; (2) that surface contour errors will have a significant effect on the optical performance of the microscope and must be controlled to a peak-to-valley variation of 50-100 A and a frequency of 8 periods over the surface of a mirror; and (3) that tolerance analysis of the spherical Schwarzschild microscope has been shown that the water window operations will require 2-3 times tighter tolerances to achieve a similar performance of operations with 130 A radiation. These results have been included in a manuscript included in the appendix.

  15. Momentum-resolved resonant inelastic X-ray scattering on a single crystal under high pressure.

    Science.gov (United States)

    Yoshida, Masahiro; Ishii, Kenji; Jarrige, Ignace; Watanuki, Tetsu; Kudo, Kazutaka; Koike, Yoji; Kumagai, Ken'ichi; Hiraoka, Nozomu; Ishii, Hirofumi; Tsuei, Ku-Ding; Mizuki, Jun'ichiro

    2014-01-01

    A single-crystal momentum-resolved resonant inelastic X-ray scattering (RIXS) experiment under high pressure using an originally designed diamond anvil cell (DAC) is reported. The diamond-in/diamond-out geometry was adopted with both the incident and scattered beams passing through a 1 mm-thick diamond. This enabled us to cover wide momentum space keeping the scattering angle condition near 90°. Elastic and inelastic scattering from the diamond was drastically reduced using a pinhole placed after the DAC. Measurement of the momentum-resolved RIXS spectra of Sr2.5Ca11.5Cu24O41 at the Cu K-edge was thus successful. Though the inelastic intensity becomes weaker by two orders than the ambient pressure, RIXS spectra both at the center and the edge of the Brillouin zone were obtained at 3 GPa and low-energy electronic excitations of the cuprate were found to change with pressure.

  16. Three-dimensional grain fabric measurements using high-resolution X-ray computed tomography

    Science.gov (United States)

    Ketcham, Richard A.

    2005-07-01

    High-resolution X-ray computed tomography (HRXCT) provides detailed imagery of the interiors of rocks up to hand-sample size, non-destructively and in three dimensions. New tools described here allow these data to be used for analysis of grain fabrics. Two separate sets of measurement techniques have been developed. The first concentrates on quantifying individual crystals (phenocrysts, porphyroblasts) or other discrete objects or void spaces within a sample. Quantifiable properties include location, size, shape, orientation, and contact relationships with adjacent objects. The second set of techniques performs a more general fabric analysis on any distinguishable component in a sample. A fabric tensor can be computed based on a number of metrics, including the star volume distribution (SVD), star length distribution (SLD), and mean intercept length (MIL) methods. The fabric tensors provide principal component directions and magnitudes, which in turn provide a measure of degree of anisotropy and shape indices. Because the SVD and SLD measure only the material of interest, whereas the MIL is also influenced by spatial distribution, results can be divergent for sparse phases. Also introduced is a three-dimensional rose diagram that can be viewed interactively and inspected to reveal further details about non-orthogonal directional components. These techniques are demonstrated through analysis of a garnet-kyanite schist from Mica Dam, British Columbia.

  17. High-resolution interference-monochromator for hard X-rays.

    Science.gov (United States)

    Tsai, Yi-Wei; Chang, Ying-Yi; Wu, Yu-Hsin; Lee, Kun-Yuan; Liu, Shih-Lun; Chang, Shih-Lin

    2016-12-26

    An X-ray interference-monochromator combining a Fabry-Perot resonator (FPR) and a double-crystal monochromator (DCM) is proposed and realized for obtaining single-mode X-rays with 3.45 meV energy resolution. The monochromator is based on the generation of cavity interference fringes from a FPR and single-mode selection of the transmission spectrum by a DCM of a nearly backward symmetric reflection geometry. The energy of the monochromator can be tuned within 2500 meV(= ΔE) by temperature control of the FPR and the DCM crystals in the range of ΔT = 70 K at room temperature. The diffraction geometry and small size of the optical components used make the interference-monochromator very easy to be adapted in modern synchrotron beamlines and X-ray optics applications.

  18. Small-Size High-Current Generators for X-Ray Backlighting

    Science.gov (United States)

    Chaikovsky, S. A.; Artyomov, A. P.; Zharova, N. V.; Zhigalin, A. S.; Lavrinovich, I. V.; Oreshkin, V. I.; Ratakhin, N. A.; Rousskikh, A. G.; Fedunin, A. V.; Fedushchak, V. F.; Erfort, A. A.

    2017-12-01

    The paper deals with the soft X-ray backlighting based on the X-pinch as a powerful tool for physical studies of fast processes. Proposed are the unique small-size pulsed power generators operating as a low-inductance capacitor bank. These pulse generators provide the X-pinch-based soft X-ray source (hν = 1-10 keV) of micron size at 2-3 ns pulse duration. The small size and weight of pulse generators allow them to be transported to any laboratory for conducting X-ray backlighting of test objects with micron space resolution and nanosecond exposure time. These generators also allow creating synchronized multi-frame radiographic complexes with frame delay variation in a broad range.

  19. HIGH-ENERGY X-RAY PINHOLE CAMERA FOR HIGH-RESOLUTION ELECTRON BEAM SIZE MEASUREMENTS

    Energy Technology Data Exchange (ETDEWEB)

    Yang, B.; Morgan, J.; Lee, S.H.; Shang, H.

    2017-03-25

    The Advanced Photon Source (APS) is developing a multi-bend achromat (MBA) lattice based storage ring as the next major upgrade, featuring a 20-fold reduction in emittance. Combining the reduction of beta functions, the electron beam sizes at bend magnet sources may be reduced to reach 5 – 10 µm for 10% vertical coupling. The x-ray pinhole camera currently used for beam size monitoring will not be adequate for the new task. By increasing the operating photon energy to 120 – 200 keV, the pinhole camera’s resolution is expected to reach below 4 µm. The peak height of the pinhole image will be used to monitor relative changes of the beam sizes and enable the feedback control of the emittance. We present the simulation and the design of a beam size monitor for the APS storage ring.

  20. Infrared LED Enhanced Spectroscopic CdZnTe Detector Working under High Fluxes of X-rays.

    Science.gov (United States)

    Pekárek, Jakub; Dědič, Václav; Franc, Jan; Belas, Eduard; Rejhon, Martin; Moravec, Pavel; Touš, Jan; Voltr, Josef

    2016-09-27

    This paper describes an application of infrared light-induced de-polarization applied on a polarized CdZnTe detector working under high radiation fluxes. We newly demonstrate the influence of a high flux of X-rays and simultaneous 1200-nm LED illumination on the spectroscopic properties of a CdZnTe detector. CdZnTe detectors operating under high radiation fluxes usually suffer from the polarization effect, which occurs due to a screening of the internal electric field by a positive space charge caused by photogenerated holes trapped at a deep level. Polarization results in the degradation of detector charge collection efficiency. We studied the spectroscopic behavior of CdZnTe under various X-ray fluxes ranging between 5 × 10 5 and 8 × 10 6 photons per mm 2 per second. It was observed that polarization occurs at an X-ray flux higher than 3 × 10 6 mm - 2 ·s - 1 . Using simultaneous illumination of the detector by a de-polarizing LED at 1200 nm, it was possible to recover X-ray spectra originally deformed by the polarization effect.

  1. Infrared LED Enhanced Spectroscopic CdZnTe Detector Working under High Fluxes of X-rays

    Directory of Open Access Journals (Sweden)

    Jakub Pekárek

    2016-09-01

    Full Text Available This paper describes an application of infrared light-induced de-polarization applied on a polarized CdZnTe detector working under high radiation fluxes. We newly demonstrate the influence of a high flux of X-rays and simultaneous 1200-nm LED illumination on the spectroscopic properties of a CdZnTe detector. CdZnTe detectors operating under high radiation fluxes usually suffer from the polarization effect, which occurs due to a screening of the internal electric field by a positive space charge caused by photogenerated holes trapped at a deep level. Polarization results in the degradation of detector charge collection efficiency. We studied the spectroscopic behavior of CdZnTe under various X-ray fluxes ranging between 5 × 10 5 and 8 × 10 6 photons per mm 2 per second. It was observed that polarization occurs at an X-ray flux higher than 3 × 10 6 mm − 2 ·s − 1 . Using simultaneous illumination of the detector by a de-polarizing LED at 1200 nm, it was possible to recover X-ray spectra originally deformed by the polarization effect.

  2. Joint x-ray

    Science.gov (United States)

    X-ray - joint; Arthrography; Arthrogram ... x-ray technologist will help you position the joint to be x-rayed on the table. Once in place, pictures are taken. The joint may be moved into other positions for more ...

  3. High-speed, two-dimensional synchrotron white-beam x-ray radiography of spray breakup and atomization

    Energy Technology Data Exchange (ETDEWEB)

    Halls, Benjamin R.; Radke, Christopher D.; Reuter, Benjamin J.; Kastengren, Alan L.; Gord, James R.; Meyer, Terrence R.

    2017-01-01

    High-speed, two-dimensional synchrotron x-ray radiography and phase-contrast imaging are demonstrated in propulsion sprays. Measurements are performed at the 7-BM beamline at the Advanced Photon Source user facility at Argonne National Laboratory using a recently developed broadband x-ray white beam. This novel enhancement allows for high speed, high fidelity x-ray imaging for the community at large. Quantitative path-integrated liquid distributions and spatio-temporal dynamics of the sprays were imaged with a LuAG:Ce scintillator optically coupled to a high-speed CMOS camera. Images are collected with a microscope objective at frame rates of 20 kHz and with a macro lens at 120 kHz, achieving spatial resolutions of 12 μm and 65 μm, respectively. Imaging with and without potassium iodide (KI) as a contrast-enhancing agent is compared, and the effects of broadband attenuation and spatial beam characteristics are determined through modeling and experimental calibration. In addition, phase contrast is used to differentiate liquid streams with varying concentrations of KI. The experimental approach is applied to different spray conditions, including quantitative measurements of mass distribution during primary atomization and qualitative visualization of turbulent binary fluid mixing. High-speed, two-dimensional synchrotron white-beam x-ray radiography of spray breakup and atomization. Available from: https://www.researchgate.net/publication/312567827_High-speed_two-dimensional_synchrotron_white-beam_x-ray_radiography_of_spray_breakup_and_atomization [accessed Aug 31, 2017].

  4. Low Dose X-Ray Sources and High Quantum Efficiency Sensors: The Next Challenge in Dental Digital Imaging?

    Directory of Open Access Journals (Sweden)

    Arnav R. Mistry

    2014-01-01

    Full Text Available Objective(s. The major challenge encountered to decrease the milliamperes (mA level in X-ray imaging systems is the quantum noise phenomena. This investigation evaluated dose exposure and image resolution of a low dose X-ray imaging (LDXI prototype comprising a low mA X-ray source and a novel microlens-based sensor relative to current imaging technologies. Study Design. A LDXI in static (group 1 and dynamic (group 2 modes was compared to medical fluoroscopy (group 3, digital intraoral radiography (group 4, and CBCT scan (group 5 using a dental phantom. Results. The Mann-Whitney test showed no statistical significance (α=0.01 in dose exposure between groups 1 and 3 and 1 and 4 and timing exposure (seconds between groups 1 and 5 and 2 and 3. Image resolution test showed group 1 > group 4 > group 2 > group 3 > group 5. Conclusions. The LDXI proved the concept for obtaining a high definition image resolution for static and dynamic radiography at lower or similar dose exposure and smaller pixel size, respectively, when compared to current imaging technologies. Lower mA at the X-ray source and high QE at the detector level principles with microlens could be applied to current imaging technologies to considerably reduce dose exposure without compromising image resolution in the near future.

  5. In situ electrochemical high-energy X-ray diffraction using a capillary working electrode cell geometry.

    Science.gov (United States)

    Young, Matthias J; Bedford, Nicholas M; Jiang, Naisheng; Lin, Deqing; Dai, Liming

    2017-07-01

    The ability to generate new electrochemically active materials for energy generation and storage with improved properties will likely be derived from an understanding of atomic-scale structure/function relationships during electrochemical events. Here, the design and implementation of a new capillary electrochemical cell designed specifically for in situ high-energy X-ray diffraction measurements is described. By increasing the amount of electrochemically active material in the X-ray path while implementing low-Z cell materials with anisotropic scattering profiles, an order of magnitude enhancement in diffracted X-ray signal over traditional cell geometries for multiple electrochemically active materials is demonstrated. This signal improvement is crucial for high-energy X-ray diffraction measurements and subsequent Fourier transformation into atomic pair distribution functions for atomic-scale structural analysis. As an example, clear structural changes in LiCoO2 under reductive and oxidative conditions using the capillary cell are demonstrated, which agree with prior studies. Accurate modeling of the LiCoO2 diffraction data using reverse Monte Carlo simulations further verifies accurate background subtraction and strong signal from the electrochemically active material, enabled by the capillary working electrode geometry.

  6. A hybrid concept (segmented plus monolithic fused silica shells) for a high-throughput and high-angular resolution x-ray mission (Lynx/X-Ray Surveyor like)

    Science.gov (United States)

    Basso, Stefano; Civitani, Marta; Pareschi, Giovanni; Parodi, Giancarlo

    2017-09-01

    Lynx is a large area and high angular resolution X-ray mission being studied by NASA to be presented to the next Decadal Survey for the implementation in the next decade. It aims to realize an X-ray telescope with the effective area similar to Athena (2 m2 at 1 keV) but with the same angular resolution of Chandra and a much larger Field Of View (up 20 arcmin x 20 arcmin). The science of X-ray Surveyor requires a large-throughput mirror assembly with sub-arcsec angular resolution. These future X-ray mirrors have a set of requirements which, collectively, represents very substantial advances over any currently in operation or planned for missions other than X-ray Surveyor. Of particular importance is achieving low mass per unit collecting area, while maintaining Chandra like angular resolution. Among the possible solutions under study, the direct polishing of both thin monolithic pseudo-cylindrical shells and segments made of fused silica are being considered as viable solutions for the implementation of the mirrors. Fused silica has very good thermomechanical parameters (including a very low CTE), making the material particularly well suited for for the production of the Lynx mirrors. It should be noted that the use of close shells is also very attractive, since the operations for the integration of the shells will be greatly simplified and the area lost due to the vignetting from the interfacing structures minimized even if the management of such big (diameter of 3 m) and thin shells have to be demonstrated. In this paper we will discuss a possible basic layout for a full shell mirror and a hybrid concept (segmented plus monolithic shells made of fused silica) as a second solution, for the Lynx/XRS telescope, discussing preliminary results in terms of optical and mechanical performance.

  7. Optical Demonstration of a Medical Imaging System with an EMCCD-Sensor Array for Use in a High Resolution Dynamic X-ray Imager

    OpenAIRE

    Qu, Bin; Huang, Ying; Wang, Weiyuan; Sharma, Prateek; Kuhls-Gilcrist, Andrew T.; Cartwright, Alexander N.; Titus, Albert H.; Bednarek, Daniel R.; Rudin, Stephen

    2010-01-01

    Use of an extensible array of Electron Multiplying CCDs (EMCCDs) in medical x-ray imager applications was demonstrated for the first time. The large variable electronic-gain (up to 2000) and small pixel size of EMCCDs provide effective suppression of readout noise compared to signal, as well as high resolution, enabling the development of an x-ray detector with far superior performance compared to conventional x-ray image intensifiers and flat panel detectors. We are developing arrays of EMCC...

  8. High reflectance Cr/C multilayer at 250 eV for soft X-ray polarimetry

    Energy Technology Data Exchange (ETDEWEB)

    Wen, Mingwu; Jiang, Li; Zhang, Zhong; Huang, Qiushi [MOE Key Laboratory of Advanced Micro-Structured Materials, Institute of Precision Optical Engineering (IPOE), School of Physics Science and Engineering, Tongji University, Shanghai 200092 (China); Wang, Zhanshan, E-mail: wangzs@tongji.edu.cn [MOE Key Laboratory of Advanced Micro-Structured Materials, Institute of Precision Optical Engineering (IPOE), School of Physics Science and Engineering, Tongji University, Shanghai 200092 (China); She, Rui; Feng, Hua [Department of Engineering Physics, Tsinghua University, Beijing (China); Wang, Hongchang [Diamond Light Source, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0DE (United Kingdom)

    2015-10-01

    X-ray reflection near 45° via multilayer mirrors can be used for astronomical polarization measurements. A Cr/C multilayer mirror (designed for X-ray polarimetry at 250 eV), with a period thickness of 3.86 nm and a bi-layer number of 100, was fabricated using direct current magnetron sputtering. Grazing incidence X-ray reflectometry at 8 keV and transmission electron microscopy were used to investigate the multilayer structure. Different models were introduced to fit the hard X-ray reflectivity curve, which indicates that the layer thickness of two materials slightly drifts from the bottom to the top of the stack. Both the chromium and carbon layers are amorphous with asymmetric interfaces, while the Cr-on-C interface is slightly wider. Based on the good quality of the multilayer structure, a high reflectivity of 21.8% for the s-polarized light was obtained at 250 eV at a grazing incidence angle of 40.7°. The fabricated Cr/C multilayer mirror exhibits high reflectivity and polarization levels in the energy region of 240 eV–260 eV. - Highlights: • We fabricated Cr/C multilayer with 3.8 nm d-spacing. • X-ray reflectometry was used to determine the exact structure of Cr/C multilayer. • A high reflectivity of 21.8% for the s-polarized light was obtained at 250 eV. • Both Cr and C were found to be amorphous with slightly asymmetric interfaces. • A 4-layer model was used to fit and explain the results.

  9. Superorbital Periodic Modulation in Wind-Accretion High-Mass X-Ray Binaries from Swift Burst Alert Telescope Observations

    Science.gov (United States)

    Corbet, Robin H. D.; Krimm, Hans A.

    2013-01-01

    We report the discovery using data from the Swift-Burst Alert Telescope (BAT) of superorbital modulation in the wind-accretion supergiant high-mass X-ray binaries 4U 1909+07 (= X 1908+075), IGR J16418-4532, and IGR J16479-4514. Together with already known superorbital periodicities in 2S 0114+650 and IGR J16493-4348, the systems exhibit a monotonic relationship between superorbital and orbital periods. These systems include both supergiant fast X-ray transients and classical supergiant systems, and have a range of inclination angles. This suggests an underlying physical mechanism which is connected to the orbital period. In addition to these sources with clear detections of superorbital periods, IGR J16393-4643 (= AX J16390.4-4642) is identified as a system that may have superorbital modulation due to the coincidence of low-amplitude peaks in power spectra derived from BAT, Rossi X-Ray Timing Explorer Proportional Counter Array, and International Gamma-Ray Astrophysics Laboratory light curves. 1E 1145.1-6141 may also be worthy of further attention due to the amount of low-frequency modulation of its light curve. However, we find that the presence of superorbital modulation is not a universal feature of wind-accretion supergiant X-ray binaries.

  10. NuSTAR detection of high-energy X-ray emission and rapid variability from sagittarius A* flares

    DEFF Research Database (Denmark)

    Barrière, Nicolas M.; Tomsick, John A.; Baganoff, Frederick K.

    2014-01-01

    Sagittarius A* harbors the supermassive black hole that lies at the dynamical center of our Galaxy. Sagittarius A* spends most of its time in a low luminosity emission state but flares frequently in the infrared and X-ray, increasing up to a few hundred fold in brightness for up to a few hours...... at a time. The physical processes giving rise to the X-ray flares are uncertain. Here we report the detection with the NuSTAR observatory in Summer and Fall 2012 of four low to medium amplitude X-ray flares to energies up to 79 keV. For the first time, we clearly see that the power-law spectrum...... of Sagittarius A* X-ray flares extends to high energy, with no evidence for a cutoff. Although the photon index of the absorbed power-law fits are in agreement with past observations, we find a difference between the photon index of two of the flares (significant at the 95% confidence level). The spectra...

  11. Exploring X-ray lasing in nitrogen pinch plasma at very high and fast discharge current excitation

    Science.gov (United States)

    Barnwal, S.; Nigam, S.; Aneesh, K.; Prasad, Y. B. S. R.; Sharma, M. L.; Tripathi, P. K.; Joshi, A. S.; Naik, P. A.; Vora, H. S.; Gupta, P. D.

    2017-06-01

    The possibility to demonstrate X-ray lasing in nitrogen at 13.4 nm through recombination scheme driven by capillary discharge excitation has been explored at a high discharge current of 95 kA, with 46 ns quarter period. The emission from nitrogen pinch plasma showed a fast pulse at the instant of pinch formation, overriding the long duration Bremsstrahlung emission. The spectroscopic study revealed dominant X-ray line emissions at 2.8 and 2.1 nm, apart from various X-ray line emissions at higher wavelengths. Line emission at 2.8 nm confirms the formation of NVI charge state of nitrogen. At lower pressures, faint emission of Ly-α line at 2.4 nm indicated formation of NVII ions by further heating. The favourable role of pre-pulse in the formation of higher charge states of nitrogen was also established beyond doubt. This study provides important inputs for future experiments towards demonstration of X-ray lasing at 13.4 nm.

  12. Constraints on cold dark matter theories from observations of massive x-ray-luminous clusters of galaxies at high redshift

    Science.gov (United States)

    Luppino, G. A.; Gioia, I. M.

    1995-01-01

    During the course of a gravitational lensing survey of distant, X-ray selected Einstein Observatory Extended Medium Sensitivity Survey (EMSS) clusters of galaxies, we have studied six X-ray-luminous (L(sub x) greater than 5 x 10(exp 44)(h(sub 50)(exp -2))ergs/sec) clusters at redshifts exceeding z = 0.5. All of these clusters are apparently massive. In addition to their high X-ray luminosity, two of the clusters at z approximately 0.6 exhibit gravitationally lensed arcs. Furthermore, the highest redshift cluster in our sample, MS 1054-0321 at z = 0.826, is both extremely X-ray luminous (L(sub 0.3-3.5keV)=9.3 x 10(exp 44)(h(sub 50)(exp -2))ergs/sec) and exceedingly rich with an optical richness comparable to an Abell Richness Class 4 cluster. In this Letter, we discuss the cosmological implications of the very existence of these clusters for hierarchical structure formation theories such as standard Omega = 1 CDM (cold dark matter), hybrid Omega = 1 C + HDM (hot dark matter), and flat, low-density Lambda + CDM models.

  13. Modeling Gamma-Ray Emission From the High-Mass X-Ray Binary LS 5039

    Directory of Open Access Journals (Sweden)

    Stan Owocki

    2012-03-01

    Full Text Available A few high-mass X-ray binaries–consisting of an OB star plus compact companion– have been observed by Fermi and ground-based Cerenkov telescopes like High Energy Stereoscopic System (HESS to be sources of very high energy (VHE; up to 30 TeV γ-rays. This paper focuses on the prominent γ-ray source, LS 5039, which consists of a massive O6.5V star in a 3.9-day-period, mildly elliptical (e ≈ 0.24 orbit with its companion, assumed here to be an unmagnetized compact object (e.g., black hole. Using three dimensional smoothed particle hydrodynamics simulations of the Bondi-Hoyle accretion of the O-star wind onto the companion, we find that the orbital phase variation of the accretion follows very closely the simple Bondi-Hoyle-Lyttleton (BHL rate for the local radius and wind speed. Moreover, a simple model, wherein intrinsic emission of γ-rays is assumed to track this accretion rate, reproduces quite well Fermi observations of the phase variation of γ-rays in the energy range 0.1-10 GeV. However for the VHE (0.1-30 TeV radiation observed by the HESS Cerenkov telescope, it is important to account also for photon-photon interactions between the γ-rays and the stellar optical/UV radiation, which effectively attenuates much of the strong emission near periastron. When this is included, we find that this simple BHL accretion model also quite naturally fits the HESS light curve, thus making it a strong alternative to the pulsar-wind-shock models commonly invoked to explain such VHE γ-ray emission in massive-star binaries.

  14. X-Ray Absorption Spectroscopic Studies of High-Spin Nonheme (Alkylperoxo)Iron(III) Intermediates

    Energy Technology Data Exchange (ETDEWEB)

    Shan, X.; Rohde, J.-U.; Koehntop, K.D.; Zhou, Y.; Bukowski, M.R.; Costas, M.; Fujisawa, K.; Que, L.; Jr.

    2009-06-04

    The reactions of iron(II) complexes [Fe(Tp{sup t-Bu,i-Pr})(OH)] (1a, Tp{sup t-Bu,i-Pr} = hydrotris(3-tert-butyl-5-isopropyl-1-pyrazolyl)borate), [Fe(6-Me{sub 2}BPMCN)(OTf){sub 2}] (1b, 6-Me{sub 2}BPMCN = N,N'-bis((2-methylpyridin-6-yl)methyl)-N,N'-dimethyl-trans-1,2-diaminocyclohexane), and [Fe(L{sup 8}Py{sub 2})(OTf)](OTf) (1c, L{sup 8}Py{sub 2} = 1,5-bis(pyridin-2-ylmethyl)-1,5-diazacyclooctane) with tert-BuOOH give rise to high-spin Fe{sup III}-OOR complexes. X-ray absorption spectra (XAS) of these high-spin species show characteristic features, distinct from those of low-spin Fe-OOR complexes (Rohde, J.-U.; et al. J. Am. Chem. Soc. 2004, 126, 16750--16761). These include (1) an intense 1s {yields} 3d preedge feature, with an area around 20 units, (2) an edge energy, ranging from 7122 to 7126 eV, that is affected by the coordination environment, and (3) a 1.86--1.96 {angstrom} Fe-OOR bond, compared to the 1.78 {angstrom} Fe-OOR bond in low-spin complexes. These unique features likely arise from a flexible first coordination sphere in those complexes. The difference in Fe-OOR bond length may rationalize differences in reactivity between low-spin and high-spin Fe{sup III}-OOR species.

  15. Short period, high field cryogenic undulator for extreme performance x-ray free electron lasers

    Directory of Open Access Journals (Sweden)

    F. H. O’Shea

    2010-07-01

    Full Text Available Short period, high field undulators can enable short wavelength free electron lasers (FELs at low beam energy, with decreased gain length, thus allowing much more compact and less costly FEL systems. We describe an ongoing initiative to develop such an undulator based on an approach that utilizes novel cryogenic materials. While this effort was begun in the context of extending the photon energy regime of a laser-plasma accelerator based electron source, we consider here implications of its application to sub-fs scenarios in which more conventional injectors are employed. The use of such low-charge, ultrashort beams, which has recently been proposed as a method of obtaining single-spike performance in x-ray FELs, is seen in simulation to give unprecedented beam brightness. This brightness, when considered in tandem with short wavelength, high field undulators, enables extremely high performance FELs. Two examples discussed in this paper illustrate this point well. The first is the use of the SPARX injector at 2.1 GeV with 1 pC of charge to give 8 GW peak power in a single spike at 6.5 Å with a photon beam peak brightness greater than 10^{35}  photons/(s mm^{2} mrad^{2}  0.1%  BW, which will also reach LCLS wavelengths on the 5th harmonic. The second is the exploitation of the LCLS injector with 0.25 pC, 150 as pulses to lase at 1.5 Å using only 4.5 GeV energy; beyond this possibility, we present start-to-end simulations of lasing at unprecedented short wavelength, 0.15 Å, using 13.65 GeV LCLS design energy.

  16. Determination of low levels of retained austenite in low-carbon high-manganese steel using X-ray diffraction

    Energy Technology Data Exchange (ETDEWEB)

    Carvalho Ferreira, Helder, E-mail: helder.ferreira@arcelormittal.com.br [ArcelorMittal Monlevade, Av. Getúlio Vargas, 100, 35930-000 João Monlevade, MG (Brazil); Jose Martins Boratto, Francisco, E-mail: francisco_boratto@yahoo.com.br [Independent Consultant, Av. Aeroporto, 9, 35930-438 João Monlevade, MG (Brazil); Tadeu Lopes Buono, Vicente, E-mail: vbuono@demet.ufmg.br [Universidade Federal de Minas Gerais, Av. Antonio Carlos, 6627, 31270-901 Belo Horizonte, MG (Brazil)

    2015-03-25

    A method involving the decomposition of the X-ray diffraction (XRD) peaks for the single wavelengths Kα{sub 1} and Kα{sub 2} was used to quantify the amount of retained austenite at levels lower than 5% in low-carbon high-manganese steels. By applying this method, it was possible to use the two main peaks of austenite (γ) and the two main peaks of ferrite (α) in the calculations, despite the partial overlapping of the (111)γ and (110)α peaks. The diffraction peaks were modeled with the Pearson VII equation using a nonlinear least-squares optimization technique. This allowed the integrated intensities of the XRD peaks to be calculated using only the Kα{sub 1} side. The method was used to measure the levels of retained austenite in samples of a metal-inert gas steel welding rod cooled at the rates of 10 °C/s and 1.6 °C/s. The accuracy of the method was determined by performing six measurements in different directions in both the longitudinal and the transverse section of the 1.6 °C/s sample.

  17. In situ MEMS testing: correlation of high-resolution X-ray diffraction with mechanical experiments and finite element analysis.

    Science.gov (United States)

    Schifferle, Andreas; Dommann, Alex; Neels, Antonia

    2017-01-01

    New methods are needed in microsystems technology for evaluating microelectromechanical systems (MEMS) because of their reduced size. The assessment and characterization of mechanical and structural relations of MEMS are essential to assure the long-term functioning of devices, and have a significant impact on design and fabrication. Within this study a concept for the investigation of mechanically loaded MEMS materials on an atomic level is introduced, combining high-resolution X-ray diffraction (HRXRD) measurements with finite element analysis (FEA) and mechanical testing. In situ HRXRD measurements were performed on tensile loaded single crystal silicon (SCSi) specimens by means of profile scans and reciprocal space mapping (RSM) on symmetrical (004) and (440) reflections. A comprehensive evaluation of the rather complex XRD patterns and features was enabled by the correlation of measured with simulated, 'theoretical' patterns. Latter were calculated by a specifically developed, simple and fast approach on the basis of continuum mechanical relations. Qualitative and quantitative analysis confirmed the admissibility and accuracy of the presented method. In this context [001] Poisson's ratio was determined providing an error of less than 1.5% with respect to analytical prediction. Consequently, the introduced procedure contributes to further going investigations of weak scattering being related to strain and defects in crystalline structures and therefore supports investigations on materials and devices failure mechanisms.

  18. The X-Ray Optics for the High Angular Resolution Imager (HARI)

    Science.gov (United States)

    Weisskopf, M. C.

    2010-01-01

    This slide presentation shows the basic parameters of the x-ray optics, the housing,a graph of the effective area vs energy, another graph showing the angular off-set vs HEW, and a series of graphs showing the detector offsets and tilts,

  19. High performance X-ray and neutron microfocusing optics. Phase II final report.

    Energy Technology Data Exchange (ETDEWEB)

    Gregory Hirsch

    2000-01-14

    The use of extremely small diameter x-ray beams at synchrotron radiation facilities has become an important experimental technique for investigators in many other scientific disciplines. While there have been several different optical elements developed for producing such microbeams, this SBIR project was concerned with one particular device: the tapered-monocapillary optic.

  20. From lows to highs: using low-resolution models to phase X-ray data

    Energy Technology Data Exchange (ETDEWEB)

    Stuart, David I. [University of Oxford, Roosevelt Drive, Headington, Oxford OX3 7BN (United Kingdom); Diamond Light Source Ltd, Diamond House, Harwell Science and Innovation Campus, Didcot (United Kingdom); Abrescia, Nicola G. A., E-mail: nabrescia@cicbiogune.es [CIC bioGUNE, CIBERehd, Bizkaia Technology Park, Bld 800, 48160 Derio (Spain); IKERBASQUE, Basque Foundation for Science, 48011 Bilbao (Spain); University of Oxford, Roosevelt Drive, Headington, Oxford OX3 7BN (United Kingdom)

    2013-11-01

    An unusual example of how virus structure determination pushes the limits of the molecular replacement method is presented. The study of virus structures has contributed to methodological advances in structural biology that are generally applicable (molecular replacement and noncrystallographic symmetry are just two of the best known examples). Moreover, structural virology has been instrumental in forging the more general concept of exploiting phase information derived from multiple structural techniques. This hybridization of structural methods, primarily electron microscopy (EM) and X-ray crystallography, but also small-angle X-ray scattering (SAXS) and nuclear magnetic resonance (NMR) spectroscopy, is central to integrative structural biology. Here, the interplay of X-ray crystallography and EM is illustrated through the example of the structural determination of the marine lipid-containing bacteriophage PM2. Molecular replacement starting from an ∼13 Å cryo-EM reconstruction, followed by cycling density averaging, phase extension and solvent flattening, gave the X-ray structure of the intact virus at 7 Å resolution This in turn served as a bridge to phase, to 2.5 Å resolution, data from twinned crystals of the major coat protein (P2), ultimately yielding a quasi-atomic model of the particle, which provided significant insights into virus evolution and viral membrane biogenesis.

  1. High-pressure X-ray diffraction of L-ALANINE crystal

    DEFF Research Database (Denmark)

    Olsen, J.S.; Gerward, Leif; Souza, A.G.

    2006-01-01

    L-ALANINE has been studied by X-ray diffraction at ambient temperature and pressure up to 10.3 GPa. The material is found to transform to a tetragonal structure between 2 and 3 GPa. and to a monoclinic structure between 8 and 10 GPa. The experimental bulk modulus is 25(5) GPa for the orthorhombic...

  2. Calibration of the Nustar High-Energy Focusing X-Ray Telescope

    DEFF Research Database (Denmark)

    Madsen, Kristin K.; Harrison, Fiona A.; Markwardt, Craig B.

    2015-01-01

    We present the calibration of the Nuclear Spectroscopic Telescope Array (NuSTAR) X-ray satellite. We used the Crab as the primary effective area calibrator and constructed a piece-wise linear spline function to modify the vignetting response. The achieved residuals for all off-axis angles...

  3. High-pressure behaviour of an X-ray preionized discharge pumped XeCl laser

    NARCIS (Netherlands)

    Gerritsen, J.W.; Ernst, G.J.

    1988-01-01

    The output characteristics are described of an X-ray preionized discharge pumped XeCl laser, fed by a low-impedance pulse forming line (PFL), at pressures up to 12 bar. The influence of a multichannel rail gap placed between the PFL and the laser head on the output energy was studied. We found an

  4. Atomic physics with hard X-rays from high brilliance synchrotron light sources

    Energy Technology Data Exchange (ETDEWEB)

    Southworth, S.; Gemmell, D.

    1996-08-01

    A century after the discovery of x rays, the experimental capability for studying atomic structure and dynamics with hard, bright synchrotron radiation is increasing remarkably. Tempting opportunities arise for experiments on many-body effects, aspects of fundamental photon-atom interaction processes, and relativistic and quantum-electrodynamic phenomena. Some of these possibilities are surveyed in general terms.

  5. Toward an organ based dose prescription method for the improved accuracy of murine dose in orthovoltage x-ray irradiators

    Energy Technology Data Exchange (ETDEWEB)

    Belley, Matthew D.; Wang, Chu [Medical Physics Graduate Program, Duke University Medical Center, Durham, North Carolina 27705 (United States); Nguyen, Giao; Gunasingha, Rathnayaka [Duke Radiation Dosimetry Laboratory, Duke University Medical Center, Durham, North Carolina 27710 (United States); Chao, Nelson J. [Department of Medicine, Duke University Medical Center, Durham, North Carolina 27710 and Department of Immunology, Duke University Medical Center, Durham, North Carolina 27710 (United States); Chen, Benny J. [Department of Medicine, Duke University Medical Center, Durham, North Carolina 27710 (United States); Dewhirst, Mark W. [Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina 27710 (United States); Yoshizumi, Terry T., E-mail: terry.yoshizumi@duke.edu [Duke Radiation Dosimetry Laboratory, Duke University Medical Center, Durham, North Carolina 27710 (United States); Department of Radiology, Duke University Medical Center, Durham, North Carolina 27710 (United States); Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina 27710 (United States)

    2014-03-15

    Purpose: Accurate dosimetry is essential when irradiating mice to ensure that functional and molecular endpoints are well understood for the radiation dose delivered. Conventional methods of prescribing dose in mice involve the use of a single dose rate measurement and assume a uniform average dose throughout all organs of the entire mouse. Here, the authors report the individual average organ dose values for the irradiation of a 12, 23, and 33 g mouse on a 320 kVp x-ray irradiator and calculate the resulting error from using conventional dose prescription methods. Methods: Organ doses were simulated in the Geant4 application for tomographic emission toolkit using the MOBY mouse whole-body phantom. Dosimetry was performed for three beams utilizing filters A (1.65 mm Al), B (2.0 mm Al), and C (0.1 mm Cu + 2.5 mm Al), respectively. In addition, simulated x-ray spectra were validated with physical half-value layer measurements. Results: Average doses in soft-tissue organs were found to vary by as much as 23%–32% depending on the filter. Compared to filters A and B, filter C provided the hardest beam and had the lowest variation in soft-tissue average organ doses across all mouse sizes, with a difference of 23% for the median mouse size of 23 g. Conclusions: This work suggests a new dose prescription method in small animal dosimetry: it presents a departure from the conventional approach of assigninga single dose value for irradiation of mice to a more comprehensive approach of characterizing individual organ doses to minimize the error and uncertainty. In human radiation therapy, clinical treatment planning establishes the target dose as well as the dose distribution, however, this has generally not been done in small animal research. These results suggest that organ dose errors will be minimized by calibrating the dose rates for all filters, and using different dose rates for different organs.

  6. Development of a new micro-furnace for "in situ" high-temperature single crystal X-ray diffraction measurements

    Science.gov (United States)

    Alvaro, Matteo; Angel, Ross J.; Marciano, Claudio; Zaffiro, Gabriele; Scandolo, Lorenzo; Mazzucchelli, Mattia L.; Milani, Sula; Rustioni, Greta; Domeneghetti, Chiara M.; Nestola, Fabrizio

    2015-04-01

    Several experimental methods to reliably determine elastic properties of minerals at non-ambient conditions have been developed. In particular, different techniques for generating high-pressure and high-temperature have been successfully adopted for single-crystal and powder X-ray diffraction measurements. High temperature devices for "in-situ" measurements should provide the most controlled isothermal environment as possible across the entire sample. It is intuitive that in general, thermal gradients across the sample increase as the temperature increases. Even if the small isothermal volume required for single-crystal X-ray diffraction experiments makes such phenomena almost negligible, the design of a furnace should also aim to reduce thermal gradients by including a large thermal mass that encloses the sample. However this solution often leads to complex design that results in a restricted access to reciprocal space or attenuation of the incident or diffracted intensity (with consequent reduction of the accuracy and/or precision in lattice parameter determination). Here we present a newly-developed H-shaped Pt-Pt/Rh resistance microfurnace for in-situ high-temperature single-crystal X-ray diffraction measurements. The compact design of the furnace together with the long collimator-sample-detector distance allows us to perform measurements up to 2θ = 70° with no further restrictions on any other angular movement. The microfurnace is equipped with a water cooling system that allows a constant thermal gradient to be maintained that in turn guarantees thermal stability with oscillations smaller than 5°C in the whole range of operating T of room-T to 1200°C. The furnace has been built for use with a conventional 4-circle Eulerian geometry equipped with point detector and automated with the SINGLE software (Angel and Finger 2011) that allows the effects of crystal offsets and diffractometer aberrations to be eliminated from the refined peak positions by the 8

  7. High-throughput measurement of rice tillers using a conveyor equipped with x-ray computed tomography.

    Science.gov (United States)

    Yang, Wanneng; Xu, Xiaochun; Duan, Lingfeng; Luo, Qingming; Chen, Shangbin; Zeng, Shaoqun; Liu, Qian

    2011-02-01

    Tillering is one of the most important agronomic traits because the number of shoots per plant determines panicle number, a key component of grain yield. The conventional method of counting tillers is still manual. Under the condition of mass measurement, the accuracy and efficiency could be gradually degraded along with fatigue of experienced staff. Thus, manual measurement, including counting and recording, is not only time consuming but also lack objectivity. To automate this process, we developed a high-throughput facility, dubbed high-throughput system for measuring automatically rice tillers (H-SMART), for measuring rice tillers based on a conventional x-ray computed tomography (CT) system and industrial conveyor. Each pot-grown rice plant was delivered into the CT system for scanning via the conveyor equipment. A filtered back-projection algorithm was used to reconstruct the transverse section image of the rice culms. The number of tillers was then automatically extracted by image segmentation. To evaluate the accuracy of this system, three batches of rice at different growth stages (tillering, heading, or filling) were tested, yielding absolute mean absolute errors of 0.22, 0.36, and 0.36, respectively. Subsequently, the complete machine was used under industry conditions to estimate its efficiency, which was 4320 pots per continuous 24 h workday. Thus, the H-SMART could determine the number of tillers of pot-grown rice plants, providing three advantages over the manual tillering method: absence of human disturbance, automation, and high throughput. This facility expands the application of agricultural photonics in plant phenomics.

  8. Feasibility of using intermediate x-ray energies for highly conformal extracranial radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Dong, Peng; Yu, Victoria; Nguyen, Dan; Demarco, John; Low, Daniel A.; Sheng, Ke, E-mail: ksheng@mednet.ucla.edy [Department of Radiation Oncology, University of California Los Angeles, California 90095 (United States); Woods, Kaley; Boucher, Salime [RadiaBeam Technologies, Santa Monica, California 90404 (United States)

    2014-04-15

    Purpose: To investigate the feasibility of using intermediate energy 2 MV x-rays for extracranial robotic intensity modulated radiation therapy. Methods: Two megavolts flattening filter free x-rays were simulated using the Monte Carlo code MCNP (v4c). A convolution/superposition dose calculation program was tuned to match the Monte Carlo calculation. The modeled 2 MV x-rays and actual 6 MV flattened x-rays from existing Varian Linacs were used in integrated beam orientation and fluence optimization for a head and neck, a liver, a lung, and a partial breast treatment. A column generation algorithm was used for the intensity modulation and beam orientation optimization. Identical optimization parameters were applied in three different planning modes for each site: 2, 6 MV, and dual energy 2/6 MV. Results: Excellent agreement was observed between the convolution/superposition and the Monte Carlo calculated percent depth dose profiles. For the patient plans, overall, the 2/6 MV x-ray plans had the best dosimetry followed by 2 MV only and 6 MV only plans. Between the two single energy plans, the PTV coverage was equivalent but 2 MV x-rays improved organs-at-risk sparing. For the head and neck case, the 2MV plan reduced lips, mandible, tongue, oral cavity, brain, larynx, left and right parotid gland mean doses by 14%, 8%, 4%, 14%, 24%, 6%, 30% and 16%, respectively. For the liver case, the 2 MV plan reduced the liver and body mean doses by 17% and 18%, respectively. For the lung case, lung V20, V10, and V5 were reduced by 13%, 25%, and 30%, respectively. V10 of heart with 2 MV plan was reduced by 59%. For the partial breast treatment, the 2 MV plan reduced the mean dose to the ipsilateral and contralateral lungs by 27% and 47%, respectively. The mean body dose was reduced by 16%. Conclusions: The authors showed the feasibility of using flattening filter free 2 MV x-rays for extracranial treatments as evidenced by equivalent or superior dosimetry compared to 6 MV plans

  9. X-ray emission from a high-atomic-number z-pinch plasma created from compact wire arrays

    Energy Technology Data Exchange (ETDEWEB)

    Sanford, T.W.L.; Nash, T.J.; Marder, B.M. [and others

    1996-03-01

    Thermal and nonthermal x-ray emission from the implosion of compact tungsten wire arrays, driven by 5 MA from the Saturn accelerator, are measured and compared with LLNL Radiation-Hydro-Code (RHC) and SNL Hydro-Code (HC) numerical models. Multiple implosions, due to sequential compressions and expansions of the plasma, are inferred from the measured multiple x-radiation bursts. Timing of the multiple implosions and the thermal x-ray spectra measured between 1 and 10 keV are consistent with the RHC simulations. The magnitude of the nonthermal x-ray emission measured from 10 to 100 keV ranges from 0.02 to 0.08% of the total energy radiated and is correlated with bright-spot emission along the z-axis, as observed in earlier Gamble-11 single exploding-wire experiments. The similarities of the measured nonthermal spectrum and bright-spot emission with those measured at 0.8 MA on Gamble-II suggest a common production mechanism for this process. A model of electron acceleration across magnetic fields in highly-collisional, high-atomic-number plasmas is developed, which shows the existence of a critical electric field, E{sub c}, below which strong nonthermal electron creation (and the associated nonthermal x rays) do not occur. HC simulations show that significant nonthermal electrons are not expected in this experiment (as observed) because the calculated electric fields are at least one to two orders-of-magnitude below E{sub c}. These negative nonthermal results are confirmed by RHC simulations using a nonthermal model based on a Fokker-Plank analysis. Lastly, the lower production efficiency and the larger, more irregular pinch spots formed in this experiment relative to those measured on Gamble II suggest that implosion geometries are not as efficient as single exploding-wire geometries for warm x-ray production.

  10. Developing a CCD camera with high spatial resolution for RIXS in the soft X-ray range

    Energy Technology Data Exchange (ETDEWEB)

    Soman, M.R., E-mail: m.r.soman@open.ac.uk [e2v centre for electronic imaging, The Open University, Walton Hall, Milton Keynes MK7 6AA (United Kingdom); Hall, D.J.; Tutt, J.H.; Murray, N.J.; Holland, A.D. [e2v centre for electronic imaging, The Open University, Walton Hall, Milton Keynes MK7 6AA (United Kingdom); Schmitt, T.; Raabe, J.; Schmitt, B. [Paul Scherrer Institut, CH-5232 Villigen PSI (Switzerland)

    2013-12-11

    The Super Advanced X-ray Emission Spectrometer (SAXES) at the Swiss Light Source contains a high resolution Charge-Coupled Device (CCD) camera used for Resonant Inelastic X-ray Scattering (RIXS). Using the current CCD-based camera system, the energy-dispersive spectrometer has an energy resolution (E/ΔE) of approximately 12,000 at 930 eV. A recent study predicted that through an upgrade to the grating and camera system, the energy resolution could be improved by a factor of 2. In order to achieve this goal in the spectral domain, the spatial resolution of the CCD must be improved to better than 5 µm from the current 24 µm spatial resolution (FWHM). The 400 eV–1600 eV energy X-rays detected by this spectrometer primarily interact within the field free region of the CCD, producing electron clouds which will diffuse isotropically until they reach the depleted region and buried channel. This diffusion of the charge leads to events which are split across several pixels. Through the analysis of the charge distribution across the pixels, various centroiding techniques can be used to pinpoint the spatial location of the X-ray interaction to the sub-pixel level, greatly improving the spatial resolution achieved. Using the PolLux soft X-ray microspectroscopy endstation at the Swiss Light Source, a beam of X-rays of energies from 200 eV to 1400 eV can be focused down to a spot size of approximately 20 nm. Scanning this spot across the 16 µm square pixels allows the sub-pixel response to be investigated. Previous work has demonstrated the potential improvement in spatial resolution achievable by centroiding events in a standard CCD. An Electron-Multiplying CCD (EM-CCD) has been used to improve the signal to effective readout noise ratio achieved resulting in a worst-case spatial resolution measurement of 4.5±0.2 μm and 3.9±0.1 μm at 530 eV and 680 eV respectively. A method is described that allows the contribution of the X-ray spot size to be deconvolved from these

  11. Developing a CCD camera with high spatial resolution for RIXS in the soft X-ray range

    Science.gov (United States)

    Soman, M. R.; Hall, D. J.; Tutt, J. H.; Murray, N. J.; Holland, A. D.; Schmitt, T.; Raabe, J.; Schmitt, B.

    2013-12-01

    The Super Advanced X-ray Emission Spectrometer (SAXES) at the Swiss Light Source contains a high resolution Charge-Coupled Device (CCD) camera used for Resonant Inelastic X-ray Scattering (RIXS). Using the current CCD-based camera system, the energy-dispersive spectrometer has an energy resolution (E/ΔE) of approximately 12,000 at 930 eV. A recent study predicted that through an upgrade to the grating and camera system, the energy resolution could be improved by a factor of 2. In order to achieve this goal in the spectral domain, the spatial resolution of the CCD must be improved to better than 5 μm from the current 24 μm spatial resolution (FWHM). The 400 eV-1600 eV energy X-rays detected by this spectrometer primarily interact within the field free region of the CCD, producing electron clouds which will diffuse isotropically until they reach the depleted region and buried channel. This diffusion of the charge leads to events which are split across several pixels. Through the analysis of the charge distribution across the pixels, various centroiding techniques can be used to pinpoint the spatial location of the X-ray interaction to the sub-pixel level, greatly improving the spatial resolution achieved. Using the PolLux soft X-ray microspectroscopy endstation at the Swiss Light Source, a beam of X-rays of energies from 200 eV to 1400 eV can be focused down to a spot size of approximately 20 nm. Scanning this spot across the 16 μm square pixels allows the sub-pixel response to be investigated. Previous work has demonstrated the potential improvement in spatial resolution achievable by centroiding events in a standard CCD. An Electron-Multiplying CCD (EM-CCD) has been used to improve the signal to effective readout noise ratio achieved resulting in a worst-case spatial resolution measurement of 4.5±0.2 μm and 3.9±0.1 μm at 530 eV and 680 eV respectively. A method is described that allows the contribution of the X-ray spot size to be deconvolved from these

  12. Synchrotron X-ray diffraction studies of phase transitions and mechanical properties of nanocrystalline materials at high pressure

    Energy Technology Data Exchange (ETDEWEB)

    Prilliman, Stephen Gerald [Univ. of California, Berkeley, CA (United States)

    2003-01-01

    The behavior of nanocrystals under extreme pressure was investigated using synchrotron x-ray diffraction. A major part of this investigation was the testing of a prototype synchrotron endstation on a bend magnet beamline at the Advanced Light Source for high pressure work using a diamond anvil cell. The experiments conducted and documented here helped to determine issues of efficiency and accuracy that had to be resolved before the construction of a dedicated ''super-bend'' beamline and endstation. The major conclusions were the need for a cryo-cooled monochromator and a fully remote-controllable pressurization system which would decrease the time to change pressure and greatly reduce the error created by the re-placement of the diamond anvil cell after each pressure change. Two very different types of nanocrystal systems were studied, colloidal iron oxide (Fe2O3) and thin film TiN/BN. Iron oxide nanocrystals were found to have a transition from the γ to the α structure at a pressure strongly dependent on the size of the nanocrystals, ranging from 26 GPa for 7.2 nm nanocrystals to 37 GPa for 3.6 nm nanocrystals. All nanocrystals were found to remain in the α structure even after release of pressure. The transition pressure was also found, for a constant size (5.7 nm) to be strongly dependent on the degree of aggregation of the nanocrystals, increasing from 30 GPa for completely dissolved nanocrystals to 45 GPa for strongly aggregated nanocrystals. Furthermore, the x-ray diffraction pattern of the pressure induced α phase demonstrated a decrease in intensity for certain select peaks. Together, these observations were used to make a complete picture of the phase transition in nanocrystalline systems. The size dependence of the transition was interpreted as resulting from the extremely high surface energy of the α phase which would increase the thermodynamic offset and thereby increase the kinetic barrier to transition

  13. Hard X-Ray Flare Source Sizes Measured with the Ramaty High Energy Solar Spectroscopic Imager

    Science.gov (United States)

    Dennis, Brian R.; Pernak, Rick L.

    2009-01-01

    Ramaty High Energy Solar Spectroscopic Imager (RHESSI) observations of 18 double hard X-ray sources seen at energies above 25 keV are analyzed to determine the spatial extent of the most compact structures evident in each case. The following four image reconstruction algorithms were used: Clean, Pixon, and two routines using visibilities maximum entropy and forward fit (VFF). All have been adapted for this study to optimize their ability to provide reliable estimates of the sizes of the more compact sources. The source fluxes, sizes, and morphologies obtained with each method are cross-correlated and the similarities and disagreements are discussed. The full width at half-maximum (FWHM) of the major axes of the sources with assumed elliptical Gaussian shapes are generally well correlated between the four image reconstruction routines and vary between the RHESSI resolution limit of approximately 2" up to approximately 20" with most below 10". The FWHM of the minor axes are generally at or just above the RHESSI limit and hence should be considered as unresolved in most cases. The orientation angles of the elliptical sources are also well correlated. These results suggest that the elongated sources are generally aligned along a flare ribbon with the minor axis perpendicular to the ribbon. This is verified for the one flare in our list with coincident Transition Region and Coronal Explorer (TRACE) images. There is evidence for significant extra flux in many of the flares in addition to the two identified compact sources, thus rendering the VFF assumption of just two Gaussians inadequate. A more realistic approximation in many cases would be of two line sources with unresolved widths. Recommendations are given for optimizing the RHESSI imaging reconstruction process to ensure that the finest possible details of the source morphology become evident and that reliable estimates can be made of the source dimensions.

  14. High-resolution resonant inelastic X-ray scattering with soft X-rays at the ADRESS beamline of the Swiss light source: Instrumental developments and scientific highlights

    Energy Technology Data Exchange (ETDEWEB)

    Schmitt, Thorsten, E-mail: thorsten.schmitt@psi.ch [Paul Scherrer Institut, CH-5232 Villigen PSI (Switzerland); Strocov, Vladimir N.; Zhou, Ke-Jin; Schlappa, Justine; Monney, Claude; Flechsig, Uwe; Patthey, Luc [Paul Scherrer Institut, CH-5232 Villigen PSI (Switzerland)

    2013-06-15

    Highlights: ► We have optimized the grating optics for VLS type RIXS spectrometers. ► Cu L{sub 3} RIXS can efficiently probe magnetic fluctuations in quasi-one dimensional cuprates. ► RIXS is sensitive to spin–orbital separation in one-dimensional cuprates. ► RIXS is capable to give information on interface states in oxide heterostructures. ► Mapping of electron–hole pair excitations with RIXS probes the unoccupied band structure. -- Abstract: The experimental development of the resonant inelastic X-ray scattering (RIXS) technique in the soft X-ray energy range has been tremendous during the last years. The ADRESS beamline at the Paul Scherrer Institut in Switzerland and its RIXS spectrometer SAXES has boosted the scientific capabilities with soft X-ray RIXS. Increased resolving power above 10,000 and the possibility to rotate the spectrometer to different scattering geometries allows analyzing the collective behavior of charge, orbital and spin excitations by assessing their momentum dependence. Focus of most projects at this facility lies in the investigation of low- and medium-energy excitations in correlated electron materials. In addition ADRESS has also been used for RIXS investigations on molecules in the liquid and gaseous phase. This review reports on the recent extension of the optics of the SAXES RIXS spectrometer with an additional grating optimized for the spectral range from ca. 400 to 700 eV. Furthermore, the scientific opportunities emerging from ADRESS are highlighted in RIXS studies on quasi one-dimensional cuprates, oxide heterostructures and a weakly correlated broad band material.

  15. A high-pressure vessel for X-ray diffraction experiments for liquids in a wide temperature range

    CERN Document Server

    Hosokawa, S

    2001-01-01

    An internally heated high-pressure vessel was developed for angle-dispersive X-ray scattering experiments on liquids at high-temperatures and high-pressures. It consists of a closed-end Al cylinder and a steel flange. Continuous windows made of Be cover a scattering angle range up to 55 deg. In combination with a single-crystal sapphire cell and a small heating system inside the vessel, we were able to carry out diffraction measurements for liquids in a wide temperature range up to 2000 K at high pressures up to 150 bars. Some of our recent X-ray scattering experiments using synchrotron radiation, such as inelastic scattering, high-energy elastic scattering, and anomalous scattering, are also reported.

  16. Bright Linearly and Circularly Polarized Extreme Ultraviolet and Soft X-ray High Harmonics for Absorption Spectroscopy

    Science.gov (United States)

    Fan, Tingting

    High harmonic generation (HHG) is an extreme nonlinear optical process. When implemented in a phase-matched geometry, HHG coherent upconverts femtosecond laser light into coherent "X-ray laser" beams, while retaining excellent spatial and temporal coherence, as well as the polarization state of the driving laser. HHG has a tabletop footprint, with femtosecond to attosecond time resolution, combined with nanometer spatial resolution. As a consequence of these unique capabilities, HHG is now being widely adopted for use in molecular spectroscopy and imaging, materials science, as well as nanoimaging in general. In the first half of this thesis, I demonstrate high flux linearly polarized soft X-ray HHG, driven by a single-stage 10-mJ Ti:sapphire regenerative amplifier at a repetition rate of 1 kHz. I first down-converted the laser to 1.3 mum using an optical parametric amplifier, before up-converting it into the soft X-ray region using HHG in a high-pressure, phase-matched, hollow waveguide geometry. The resulting optimally phase-matched broadband spectrum extends to 200 eV, with a soft X-ray photon flux of > 106 photons/pulse/1% bandwidth at 1 kHz, corresponding to > 109 photons/s/1% bandwidth, or approximately a three orders-of-magnitude increase compared with past work. Using this broad bandwidth X-ray source, I demonstrated X-ray absorption spectroscopy of multiple elements and transitions in molecules in a single spectrum, with a spectral resolution of 0.25 eV, and with the ability to resolve the near edge fine structure. In the second half of this thesis, I discuss how to generate the first bright circularly polarized (CP) soft X-ray HHG and also use them to implement the first tabletop X-ray magnetic circular dichroism (XMCD) measurements. Using counter-rotating CP lasers at 1.3 mum and 0.79 mum, I generated CPHHG with photon energies exceeding 160 eV. The harmonic spectra emerge as a sequence of closely spaced pairs of left and right CP peaks, with energies

  17. [Clinical applications of synchrotron radiation X-ray].

    Science.gov (United States)

    Uyama, C

    1994-09-01

    Synchrotron Radiation X-ray (SR X-ray) is an extremely strong X-ray source with a photon number more than 10(4) compared with that of the current X-ray tube. X-rays obtained by monochromatizing SR X-ray have been applied to new techniques for medical diagnosis. Several studies are now being conducted at the beam site for medical use at the Accumulation Ring of the High Energy Physics Research Institute, Tsukuba. Applications being studied include (1) energy subtraction coronary angiography. (2) microdetection of metas in samples excised from subjects. (3) monochromatic X-ray computed tomography and so on. Energy subtraction coronary angiography might have a safety advantage over the current selective coronary angiography. Microdetection of mandatory metals and poisonous heavy metals in in vivo samples contributes to the development of pathologic knowledge and clinical treatment of cancer and heavy metal toxications. Monochromatic X-ray CT is expected to detect diseases in the early stage due to increased accuracy in CT values.

  18. HIGH-PERFORMANCE COMPUTING FOR THE STUDY OF EARTH AND ENVIRONMENTAL SCIENCE MATERIALS USING SYNCHROTRON X-RAY COMPUTED MICROTOMOGRAPHY.

    Energy Technology Data Exchange (ETDEWEB)

    FENG,H.; JONES,K.W.; MCGUIGAN,M.; SMITH,G.J.; SPILETIC,J.

    2001-10-12

    Synchrotron x-ray computed microtomography (CMT) is a non-destructive method for examination of rock, soil, and other types of samples studied in the earth and environmental sciences. The high x-ray intensities of the synchrotron source make possible the acquisition of tomographic volumes at a high rate that requires the application of high-performance computing techniques for data reconstruction to produce the three-dimensional volumes, for their visualization, and for data analysis. These problems are exacerbated by the need to share information between collaborators at widely separated locations over both local and tide-area networks. A summary of the CMT technique and examples of applications are given here together with a discussion of the applications of high-performance computing methods to improve the experimental techniques and analysis of the data.

  19. In situ flow cell for combined X-ray absorption spectroscopy, X-ray diffraction, and mass spectrometry at high photon energies under solar thermochemical looping conditions

    Science.gov (United States)

    Rothensteiner, Matthäus; Jenni, Joel; Emerich, Hermann; Bonk, Alexander; Vogt, Ulrich F.; van Bokhoven, Jeroen A.

    2017-08-01

    An in situ/operando flow cell for transmission mode X-ray absorption spectroscopy (XAS), X-ray diffraction (XRD), and combined XAS/XRD measurements in a single experiment under the extreme conditions of two-step solar thermochemical looping for the dissociation of water and/or carbon dioxide was developed. The apparatus exposes materials to relevant conditions of both the auto-reduction and the oxidation sub-steps of the thermochemical cycle at ambient temperature up to 1773 K and enables determination of the composition of the effluent gases by online quadrupole mass spectrometry. The cell is based on a tube-in-tube design and is heated by means of a focusing infrared furnace. It was tested successfully for carbon dioxide splitting. In combined XAS/XRD experiments with an unfocused beam, XAS measurements were performed at the Ce K edge (40.4 keV) and XRD measurements at 64.8 keV and 55.9 keV. Furthermore, XRD measurements with a focused beam at 41.5 keV were carried out. Equimolar ceria-hafnia was auto-reduced in a flow of argon and chemically reduced in a flow of hydrogen/helium. Under reducing conditions, all cerium(iv) was converted to cerium(iii) and a cation-ordered pyrochlore-type structure was formed, which was not stable upon oxidation in a flow of carbon dioxide.

  20. A simple X-ray emitter.

    Science.gov (United States)

    Murakami, Hiroaki; Ono, Ryoichi; Hirai, Atsuhiko; Hosokawa, Yoshinori; Kawai, Jun

    2005-07-01

    A compact X-ray emission instrument is made, and the X-ray spectra are measured by changing the applied electric potential. Strong soft X-rays are observed when evacuating roughly and applying a high voltage to an insulator settled in this device. The X-ray intensity is higher as the applied voltage is increased. A light-emitting phenomenon is observed when this device emits X-rays. The present X-ray emitter is made of a small cylinder with a radius of 20 mm and a height of 50 mm. This X-ray generator has a potential to be used as an X-ray source in an X-ray fluorescence spectrometer.

  1. Development of an accelerator for X-ray inspection apparatus with high clairvoyance

    CERN Document Server

    Onishi, T

    2002-01-01

    At present, there is no portable X-ray generator usable for non-destructive inspection of thick concretes used for bridges, and so on. To enable on non-destructive inspection of such thick concrete materials with more than 300 mm in thickness, authors developed a new small size accelerator with same acceleration principle as that of betatron. And, the authors also developed two types of new induction accelerators such as 'spiral orbit type' and 'cylindrical type'. Furthermore, development of a detector with excellent sensitivity to X-ray with wavelength suitable for inspection and software for image processing are planned. Here was described acceleration principles of new accelerators, test results on prototypes of the accelerators, and development states on field emission array considering new electron gun alternating thermal one and cold cathode type electron gun using carbon nano-tubes. (G.K.)

  2. Development of an accelerator for X-ray inspection apparatus with high clairvoyance

    Energy Technology Data Exchange (ETDEWEB)

    Onishi, Takehiro [Hiroshima Univ. (Japan)

    2002-09-01

    At present, there is no portable X-ray generator usable for non-destructive inspection of thick concretes used for bridges, and so on. To enable on non-destructive inspection of such thick concrete materials with more than 300 mm in thickness, authors developed a new small size accelerator with same acceleration principle as that of betatron. And, the authors also developed two types of new induction accelerators such as 'spiral orbit type' and 'cylindrical type'. Furthermore, development of a detector with excellent sensitivity to X-ray with wavelength suitable for inspection and software for image processing are planned. Here was described acceleration principles of new accelerators, test results on prototypes of the accelerators, and development states on field emission array considering new electron gun alternating thermal one and cold cathode type electron gun using carbon nano-tubes. (G.K.)

  3. Hot-Electron Tunneling sensors for high-resolution x-ray and gamma-ray spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Mears, C.A.; Labov, S.E.; Frank, M.; Netel, H.

    1997-02-07

    Over the past 2 years, we have been studying the use of Hot Electron Tunneling sensors for use in high-energy-resolution x-ray and gamma-ray spectrometers. These sensors promise several advantages over existing cryogenic sensors, including simultaneous high count rate and high resolution capability, and relative ease of use. Using simple shadow mask lithography, we verified the basic principles of operation of these devices and discovered new physics in their thermal behavior as a function applied voltage bias. We also began to develop ways to use this new sensor in practical x-ray and gamma-ray detectors based on superconducting absorbers. This requires the use of quasiparticle trapping to concentrate the signal in the sensing elements.

  4. Method for spatially modulating 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

    2015-03-10

    A method and apparatus are provided for spatially modulating X-rays or X-ray pulses using microelectromechanical systems (MEMS) based X-ray optics. A torsionally-oscillating MEMS micromirror and a method of leveraging the grazing-angle reflection property are provided to modulate X-ray pulses with a high-degree of controllability.

  5. Electron acceleration and generation of high-brilliance x-ray radiation in kilojoule, subpicosecond laser-plasma interactions

    Directory of Open Access Journals (Sweden)

    J. Ferri

    2016-10-01

    Full Text Available Petawatt, picosecond laser pulses offer rich opportunities in generating synchrotron x-rays. This paper concentrates on the regimes accessible with the PETAL laser, which is a part of the Laser Megajoule (LMJ facility. We explore two physically distinct scenarios through Particle-in-Cell simulations. The first one realizes in a dense plasma, such that the period of electron Langmuir oscillations is much shorter than the pulse duration. Hallmarks of this regime are longitudinal breakup (“self-modulation” of the picosecond-scale laser pulse and excitation of a rapidly evolving broken plasma wake. It is found that electron beams with a charge of several tens of nC can be obtained, with a quasi-Maxwellian energy distribution extending to a few-GeV level. In the second scenario, at lower plasma densities, the pulse is shorter than the electron plasma period. The pulse blows out plasma electrons, creating a single accelerating cavity, while injection on the density downramp creates a nC quasi-monoenergetic electron bunch within the cavity. This bunch accelerates without degradation beyond 1 GeV. The x-ray sources in the self-modulated regime offer a high number of photons (∼10^{12} with the slowly decaying energy spectra extending beyond 60 keV. In turn, quasimonoenergetic character of the electron beam in the blowout regime results in the synchrotron-like spectra with the critical energy around 10 MeV and a number of photons >10^{9}. Yet, much smaller source duration and transverse size increase the x-ray brilliance by more than an order of magnitude against the self-modulated case, also favoring high spatial and temporal resolution in x-ray imaging. In all explored cases, accelerated electrons emit synchrotron x-rays of high brilliance, B>10^{20}  photons/s/mm^{2}/mrad^{2}/0.1%BW. Synchrotron sources driven by picosecond kilojoule lasers may thus find an application in x-ray diagnostics on such facilities such as the LMJ or National

  6. High numerical aperture tabletop soft x-ray diffraction microscopy with 70-nm resolution

    OpenAIRE

    Sandberg, Richard L.; Song, Changyong; Wachulak, Przemyslaw W.; Raymondson, Daisy A.; Paul, Ariel; Amirbekian, Bagrat; Lee, Edwin; Sakdinawat, Anne E.; La-O-Vorakiat, Chan; Marconi, Mario C.; Menoni, Carmen S.; Murnane, Margaret M.; Rocca, Jorge J.; Kapteyn, Henry C.; Miao, Jianwei

    2007-01-01

    Light microscopy has greatly advanced our understanding of nature. The achievable resolution, however, is limited by optical wavelengths to ≈200 nm. By using imaging and labeling technologies, resolutions beyond the diffraction limit can be achieved for specialized specimens with techniques such as near-field scanning optical microscopy, stimulated emission depletion microscopy, and photoactivated localization microscopy. Here, we report a versatile soft x-ray diffraction microscope with 70- ...

  7. High-resolution x-ray CT screening of mutant mouse models

    Science.gov (United States)

    Paulus, Michael J.; Gleason, Shaun S.; Sari-Sarraf, Hamed; Johnson, Dabney K.; Foltz, Charmaine J.; Austin, Derek W.; Easterly, M. E.; Michaud, Edward J.; Dhar, Madhu S.; Hunsicker, Patricia R.; Wall, J. W.; Schell, M.

    2000-04-01

    A dedicated small animal x-ray computed tomography system has been developed to screen mutagenized mice for anatomical phenotypes. The key components of the data acquisition instrumentation are described along with the system performance parameters. Image reconstruction, visualization and segmentation software algorithms are described. Two contrast media regimens are described and representative studies of mice with adipose, soft and skeletal tissue abnormalities are presented.

  8. Low-cost and high-resolution x-ray lithography utilizing a lift-off sputtered lead film mask on a Mylar substrate

    Science.gov (United States)

    Wisitsoraat, A.; Mongpraneet, S.; Phatthanakun, R.; Chomnawang, N.; Phokharatkul, D.; Patthanasettakul, V.; Tuantranont, A.

    2010-07-01

    In this work, a low-cost and high-resolution x-ray micromask is developed by sputtered lead film on a Mylar sheet substrate with the lift-off process and the x-ray mask is experimented for patterning SU-8 negative photoresist on a glass substrate. Sputtering is selected for Pb thick film deposition due to its high sputtering yield. The Pb mask is used for x-ray lithography of SU-8 photoresist with 5 µm closely spaced square array patterns, designed for electrowetting electrodes on a microfluidic chip. For 140 µm thick SU-8 photoresist, a Pb film thickness of around 10 µm was used to block x-rays with 95% x-ray image contrast at a critical dose of 4200 mJ cm-3. A high aspect ratio of 26.5 of SU8 microstructure with 5 µm lateral resolution has been demonstrated by the developed low-cost Pb-based x-ray mask. In addition, a steep sidewall angle of nearly 90° for SU-8 structure is confirmed. The results demonstrate that the Pb-based x-ray mask offers high-resolution x-ray lithography at a very low cost. Therefore, it is highly promising for commercial applications.

  9. X-ray diffraction and electroresistance measurements under high pressure and temperature using a large-volume cell

    Energy Technology Data Exchange (ETDEWEB)

    Principi, E; Minicucci, M [CNISM, CNR-INFM SOFT and Dipartimento di Fisica Universita degli Studi di Camerino via Madonna delle Carceri 62032, Camerino (Italy); Di Cicco, A

    2008-07-15

    In this communication we report about original experimental techniques for in-house x-ray diffraction and electrical resistance measurements under high-temperature and high pressure conditions, using large volume cells in the opposite anvil recessed geometry. The high-pressure devices we are currently using are a compact Paris-Edinburgh (PE) V5 150 Tons press and a 50 Tons standard hydraulic press, coupled usually with WC anvils and 10 mm or 7 mm boron-epoxy or pyrophyllite biconical gaskets for x-ray diffraction and resistance measurements respectively. Limiting pressures, using such a non-toroidal sample assembly and WC anvils, are about 10 GPa on samples of large sizes (10-20 mm{sup 3}). Samples can be heated using an hollow graphite cylinder as a crucible reaching temperatures as high as 2300 K, while the temperature can be measured up to 1300 K by using a K-type thermocouple. The highly automated setup developed for resistance measurements is described in details. In particular, we present electroresistance measurements of Bi melting under pressure and measurements of the Ge and LiF EOS (equation of state) at high temperature and pressure obtained using x-ray diffraction showing the sensitivity of the techniques. The relevance of these experiments to the exploitation of the potential of equipments available at synchrotron radiation facilities is emphasized.

  10. Radiological safety of food irradiation with high energy X-rays: theoretical expectations and experimental evidence

    Energy Technology Data Exchange (ETDEWEB)

    Gregoire, O. E-mail: olivier.gregoire@iba.be; Cleland, M.R.; Mittendorfer, J.; Dababneh, S.; Ehlermann, D.A.E.; Fan, X.; Kaeppeler, F.; Logar, J.; Meissner, J.; Mullier, B.; Stichelbaut, F.; Thayer, D.W

    2003-06-01

    The radiological safety of red meat irradiated with 7.5 MeV X-rays (bremsstrahlung) has been investigated theoretically and verified by dedicated experiments. Samples of meat and meat ash were located in a large volume of fresh meat at the position of the highest photoneutron fluence and irradiated to an X-ray dose of 15 kGy, twice the maximum dose allowed by the US FDA for meat irradiation. In order to evaluate the safety of treatment with any kind of electron accelerators, two experiments have been performed with different accelerators delivering electrons with a narrow and a broad energy spread. The measured activities and theoretical estimates are of the same order of magnitude. An evaluation of the corresponding radiation exposure from ingestion of the irradiated product has been compared to natural background radiation. The paper concludes that the risk to individuals from intake of food irradiated with X-rays from 7.5 MeV electrons, even with a broad energy spectrum, would be trivial.

  11. Hard X-ray bremsstrahlung production in solar flares by high-energy proton beams

    Science.gov (United States)

    Emslie, A. G.; Brown, J. C.

    1985-01-01

    The possibility that solar hard X-ray bremsstrahlung is produced by acceleration of stationary electrons by fast-moving protons, rather than vice versa, as commonly assumed, was investigated. It was found that a beam of protons which involves 1836 times fewer particles, each having an energy 1836 times greater than that of the electrons in the equivalent electron beam model, has exactly the same bremsstrahlung yield for a given target, i.e., the mechanism has an energetic efficiency equal to that of conventional bremsstrahlung models. Allowance for the different degrees of target ionization appropriate to the two models (for conventional flare geometries) makes the proton beam model more efficient than the electron beam model, by a factor of order three. The model places less stringent constraints than a conventional electron beam model on the flare energy release mechanism. It is also consistent with observed X-ray burst spectra, intensities, and directivities. The altitude distribution of hard X-rays predicted by the model agrees with observations only if nonvertical injection of the protons is assumed. The model is inconsistent with gamma-ray data in terms of conventional modeling.

  12. STRAP IV - High accuracy, low drift attitude control system.

    Science.gov (United States)

    Shrewsberry, D. J.; Budney, T. J.; Riley, D. C.; Schuler, B. C.

    1973-01-01

    The STRAP IV attitude control system was designed, tested, and successfully launched to provide stable high accuracy pointing at nontrackable X-ray sources. On its initial flight (May 19, 1972), the STRAP IV control system updated its high accuracy, rate integrating gyros on two successive stellar targets and then maneuvered the rocket body to point the experimental payload at two separate X-ray sources and an X-ray-free background location. The third axis, which remained under the control of a coarse free gyro, was updated by a technique of successive star-target coordinate transformation to ensure the correct fine-axis azimuth alignment for the high accuracy inertial maneuvers. Pointing accuracies of 4 arc min with limit cycle stability of less than 20 arc sec peak to peak were obtained on all targets.

  13. White-Beam X-ray Diffraction and Radiography Studies on High-Boron Containing Borosilicate Glass at High Pressures

    Science.gov (United States)

    Ham, Kathryn; Vohra, Yogesh; Kono, Yoshio; Wereszczak, Andrew; Patel, Parimal

    Multi-angle energy-dispersive x-ray diffraction studies and white-beam x-ray radiography were conducted with a cylindrically shaped (1 mm diameter and 0.7 mm high) high-boron content borosilicate glass sample (17.6% B2O3) to a pressure of 13.7 GPa using a Paris-Edinburgh (PE) press at Beamline 16-BM-B, HPCAT of the Advanced Photon Source. The measured structure factor S(q) to large q = 19 Å-1, is used to determine information about the internuclear bond distances between various species of atoms within the glass sample. Sample pressure was determined with gold as a pressure standard. The sample height as measured by radiography showed an overall uniaxial compression of 22.5 % at 13.7 GPa with 10.6% permanent compaction after decompression to ambient conditions. The reduced pair distribution function G(r) was extracted and Si-O, O-O, and Si-Si bond distances were measured as a function of pressure. Raman spectroscopy of pressure recovered sample as compared to starting material showed blue-shift and changes in intensity and widths of Raman bands associated with silicate and B3O6 boroxol rings. US Army Research Office under Grant No. W911NF-15-1-0614.

  14. High-intensity x-ray holography: an approach to high-resolution snapshot imaging of biological specimens

    Energy Technology Data Exchange (ETDEWEB)

    Solem, J.C.

    1982-08-01

    The crucial physical and technological issues pertaining to the holographic imaging of biological structures with a short-pulse, high-intensity, high-quantum-energy laser were examined. The limitations of x-ray optics are discussed. Alternative holographic techniques were considered, and it was concluded that far-field Fresnel transform holography (Fraunhofer holography) using a photoresist recording surface is most tractable with near term technology. The hydrodynamic expansion of inhomogeneities within the specimen is discussed. It is shown that expansion is the major source of image blurring. Analytic expressions were derived for the explosion of protein concentrations in an x-ray transparent cytoplasm, compared with numerical calculations, and corrections derived to account for the competitive transport processes by which these inhomogeneities lose energy. It is concluded that for the near term Fresnel transform holography, particularly, far-field or Fraunhofer holography, is more practical than Fourier transform holography. Of the alternative fine grain recording media for use with Fresnel transform holography, a photo-resist is most attractive. For best resolution, exposure times must be limited to a few picoseconds, and this calls for investigation of mechanisms to shutter the laser or gate the recording surface. The best contrast ratio between the nitrogen-bearing polymers (protein and the nucleic acids) and water is between the K-edges of oxygen and nitrogen.

  15. Critical-angle transmission grating technology development for high resolving power soft x-ray spectrometers on Arcus and Lynx

    Science.gov (United States)

    Heilmann, Ralf K.; Bruccoleri, Alexander R.; Song, Jungki; Kolodziejczak, Jeffery; Gaskin, Jessica A.; O'Dell, Stephen L.; Cheimetz, Peter; Hertz, Edward; Smith, Randall K.; Burwitz, Vadim; Hartner, Gisela; La Caria, Marlis-Madeleine; Schattenburg, Mark L.

    2017-08-01

    Soft x-ray spectroscopy with high resolving power (R = λ/Δλ) and large effective area (A) addresses numerous unanswered science questions about the physical laws that lead to the structure of our universe. In the soft x-ray band R > 1000 can currently only be achieved with diffraction grating-based spectroscopy. Criticalangle transmission (CAT) gratings combine the advantages of blazed reflection gratings (high efficiency, use of higher diffraction orders) with those of conventional transmission gratings (relaxed alignment tolerances and temperature requirements, transparent at higher energies, low mass), resulting in minimal mission resource requirements, while greatly improving figures of merit. Diffraction efficiency > 33% and R > 10, 000 have been demonstrated for CAT gratings. Last year the technology has been certified at Technology Readiness Level 4 based on a probe class mission concept. The Explorer-scale (A > 450 cm2 , R > 2500) grating spectroscopy Arcus mission can be built with today's CAT grating technology and has been selected in the current Explorer round for a Phase A concept study. Its figure of merit for the detection of weak absorption lines will be an order of magnitude larger than current instruments on Chandra and XMM-Newton. Further CAT grating technology development and improvements in the angular resolution of x-ray optics can provide another order of magnitude improvement in performance, as is envisioned for the X-ray Surveyor/Lynx mission concept currently under development for input into the 2020 Decadal Survey. For Arcus we have tested CAT gratings in a spectrometer setup in combination with silicon pore optics (SPO) and obtained resolving power results that exceed Arcus requirements before and after environmental testing of the gratings. We have recently fabricated the largest (32 mm x 32 mm) CAT gratings to date, and plan to increase grating size further. We mounted two of these large gratings to frames and aligned them in the

  16. X-ray optics developments at the APS for the third generation of high-energy synchrotron radiation sources.

    Science.gov (United States)

    Mills, D M

    1997-05-01

    Third-generation hard-X-ray synchrotron radiation sources simultaneously provide both a need and an opportunity for the development of new short-wavelength optical components. The high power and power densities of the insertion-device-produced X-ray beams have forced researchers to consider what may seem like exotic approaches, such as cryogenically cooled silicon and highly perfect diamond crystals, to mitigate thermal distortions in the first optical components. Once the power has been successfully filtered while maintaining the high beam brilliance, additional specialized optical components can be inserted into the monochromatic beam that take advantage of that brilliance. This paper reviews the performance of such optical components that have been designed, fabricated and tested at the Advanced Photon Source, starting with high-heat-load components and followed by examples of several specialized devices, such as an meV resolution (in-line) monochromator, a high-energy X-ray phase retarder and a phase-zone plate with submicrometer focusing capability.

  17. Resonant x-ray emission spectroscopy of liquid water: novel instrumentation, high resolution, and the"map" approach

    Energy Technology Data Exchange (ETDEWEB)

    Weinhardt, L.; Fuchs, O.; Blum, M.; B& #228; r, M.; Weigand, M.; Denlinger, J.D.; Zubavichus, Y.; Zharnikov, M.; Grunze, M.; Heske, C.; Umbach, E.

    2008-06-17

    Techniques to study the electronic structure of liquids are rare. Most recently, resonant x-ray emission spectroscopy (XES) has been shown to be an extremely versatile spectroscopy to study both occupied and unoccupied electronic states for liquids in thermodynamic equilibrium. However, XES requires high-brilliance soft x-ray synchrotron radiation and poses significant technical challenges to maintain a liquid sample in an ultra-high vacuum environment. Our group has therefore developed and constructed a novel experimental setup for the study of liquids, with the long-term goal of investigating the electronic structure of biological systems in aqueous environments. We have developed a flow-through liquid cell in which the liquid is separated from vacuum by a thin Si3N4 or SiC window and which allows a precise control of temperature. This approach has significant advantages compared to static liquids cells used in the past. Furthermore, we have designed a dedicated high-transmission, high-resolution soft x-ray spectrometer. The high transmission makes it possible to measure complete resonant XES"maps" in less than an hour, giving unprecedented detailed insight into the electronic structure of the investigated sample. Using this new equipment we have investigated the electronic structure of liquid water. Furthermore, our XES spectra and maps give information about ultra-fast dissociation on the timescale of the O 1s core hole lifetime, which is strongly affected by the initial state hydrogen bonding configuration.

  18. High-sensitivity, portable, tunable imaging X-ray spectrometer based on a spherical crystal and MCP

    CERN Document Server

    Monot, P; Dobosz, S; D'Oliveira, P; Hulin, S; Bougeard, M; Faenov, A Y; Pikuz, T A; Skobelev, I Y

    2002-01-01

    A portable (200x100x100 mm sup 3), high-luminosity, spherically bent crystal spectrometer was designed to measure very low emissivity X-ray spectra of different elements with spatial resolution in a wide spectral range (1.2-19.6 A). A large (50x15 mm sup 2) open aperture mica spherically bent crystal with R=150 mm was used as dispersive and focusing element. This spectrometer was associated with a large sensitive area (phi=40 mm) micro-channel plates assembly. This apparatus provides simultaneously high spectral (lambda/delta lambda approx 1800) and spatial (100-200 mu m) resolutions. Its large tunability allowed, without any adjustment of the spectrometer set-up, to record spectra in the 1.38-17.5 A wavelength range. We used the X-ray emission of femtosecond laser-produced plasmas from different materials ((CF sub 2) sub n , CaF sub 2 , Cu, Al) to test the spectrometer. Thanks to the high sensitivity (high collection efficiency) of the system, high quality space-resolved X-ray spectra of Fluorine and Aluminu...

  19. X-ray imaging of subsurface dynamics in high-Z materials at the Diamond Light Source.

    Science.gov (United States)

    Eakins, D E; Chapman, D J

    2014-12-01

    In this paper, we describe a new approach enabling study of subsurface dynamics in high-Z materials using the unique combination of high-energy synchrotron X-rays, a hybrid bunch structure, and a new dynamic loading platform. We detail the design and operation of the purpose-built, portable small bore gas-gun, which was installed on the I12 high-energy beamline at the Diamond Light Source and used to drive compression waves into solid and porous metal targets. Using a hybrid bunch structure and broadband X-ray pulses of up to 300 keV, radiographic snapshots were captured during various dynamic deformation processes in cm-scale specimens, thereby contributing to a more complete understanding of the evolution of mesoscale damage. Importantly, we highlight strategies for overcoming the challenges associated with using high-energy X-rays, and suggest areas for improvement needed to advance dynamic imaging through large-scale samples of relevance to engineering scenarios. These preliminary measurements demonstrate the feasibility of probing highly transient phenomena using the presented methodology.

  20. X-ray imaging of subsurface dynamics in high-Z materials at the Diamond Light Source

    Science.gov (United States)

    Eakins, D. E.; Chapman, D. J.

    2014-12-01

    In this paper, we describe a new approach enabling study of subsurface dynamics in high-Z materials using the unique combination of high-energy synchrotron X-rays, a hybrid bunch structure, and a new dynamic loading platform. We detail the design and operation of the purpose-built, portable small bore gas-gun, which was installed on the I12 high-energy beamline at the Diamond Light Source and used to drive compression waves into solid and porous metal targets. Using a hybrid bunch structure and broadband X-ray pulses of up to 300 keV, radiographic snapshots were captured during various dynamic deformation processes in cm-scale specimens, thereby contributing to a more complete understanding of the evolution of mesoscale damage. Importantly, we highlight strategies for overcoming the challenges associated with using high-energy X-rays, and suggest areas for improvement needed to advance dynamic imaging through large-scale samples of relevance to engineering scenarios. These preliminary measurements demonstrate the feasibility of probing highly transient phenomena using the presented methodology.

  1. Developing a bright 17 keV x-ray source for probing high-energy-density states of matter at high spatial resolution

    Energy Technology Data Exchange (ETDEWEB)

    Huntington, C. M.; Park, H.-S.; Maddox, B. R.; Barrios, M. A.; Benedetti, R.; Braun, D. G.; Landen, O. L.; Wehrenberg, C. E.; Remington, B. A. [Lawrence Livermore National Laboratory, Livermore, California, 94551 (United States); Hohenberger, M.; Regan, S. P. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623 (United States)

    2015-04-15

    A set of experiments were performed on the National Ignition Facility (NIF) to develop and optimize a bright, 17 keV x-ray backlighter probe using laser-irradiated Nb foils. High-resolution one-dimensional imaging was achieved using a 15 μm wide slit in a Ta substrate to aperture the Nb He{sub α} x-rays onto an open-aperture, time integrated camera. To optimize the x-ray source for imaging applications, the effect of laser pulse shape and spatial profile on the target was investigated. Two laser pulse shapes were used—a “prepulse” shape that included a 3 ns, low-intensity laser foot preceding the high-energy 2 ns square main laser drive, and a pulse without the laser foot. The laser spatial profile was varied by the use of continuous phase plates (CPPs) on a pair of shots compared to beams at best focus, without CPPs. A comprehensive set of common diagnostics allowed for a direct comparison of imaging resolution, total x-ray conversion efficiency, and x-ray spectrum between shots. The use of CPPs was seen to reduce the high-energy tail of the x-ray spectrum, whereas the laser pulse shape had little effect on the high-energy tail. The measured imaging resolution was comparably high for all combinations of laser parameters, but a higher x-ray flux was achieved without phase plates. This increased flux was the result of smaller laser spot sizes, which allowed us to arrange the laser focal spots from multiple beams and produce an x-ray source which was more localized behind the slit aperture. Our experiments are a first demonstration of point-projection geometry imaging at NIF at the energies (>10 keV) necessary for imaging denser, higher-Z targets than have previously been investigated.

  2. The dynamic response of high pressure phase of Si using phase contrast imaging and X-ray diffraction

    Science.gov (United States)

    Lee, H. J.; Galtier, E.; Xing, Z.; Gleason, A.; Granados, E.; Tavella, F.; Schropp, A.; Seiboth, F.; Schroer, C.; Higginbotham, A.; Brown, S.; Arnold, B.; Curiel, R.; Peterswright, D.; Fry, A.; Nagler, B.

    2015-11-01

    Static compression studies have revealed that crystalline silicon undergoes phase transitions from a cubic diamond structure to a variety of phases including body-centered tetragonal phase, an orthorhombic phase, and a hexagonal primitive phase. However, the dynamic response of silicon at high pressure is not well understood. Phase contrast imaging has proven to be a powerful tool for probing density changes caused by the shock propagation into a material. With respect to the elastic and plastic compression, we image shock waves in Si with high spatial resolution using the LCLS X-ray free electron laser and Matter in Extreme Conditions instrument. In this study, the long pulse optical laser with pseudoflat top shape creates high pressures up to 60 GPa. We also measure the crystal structure by observing the X-ray diffraction orthogonal to the shock propagation direction over a range of pressure. In this talk, we will present the capability of simultaneously performing phase contrast imaging and in situ X-ray diffraction during shock loading and will discuss the dynamic response of Si in high pressure phases

  3. Measurements of internal stresses in bond coating using high energy x-rays from synchrotron radiation source

    CERN Document Server

    Suzuki, K; Akiniwa, Y; Nishio, K; Kawamura, M; Okado, H

    2002-01-01

    Thermal barrier coating (TBC) techniques enable high temperature combustion of turbines made of Ni-base alloy. TBC is made of zirconia top coating on NiCoCrAlY bond coating. The internal stresses in the bond coating play essential role in the delamination or fracture of TBC in service. With the X-rays from laboratory equipments, it is impossible to measure nondestructively the internal stress in the bond coating under the top coating. synchrotron radiations with a high energy and high brightness have a large penetration depth as compared with laboratory X-rays. Using the high energy X-rays from the synchrotron radiation, it is possible to measure the internal stress in the bond coating through the top coating. In this study, the furnace, which can heat a specimen to 1473 K, was developed for the stress measurement of the thermal barrier coatings. The internal stresses in the bond coating were measured at the room temperature, 773 K, 1073 K and 1373 K by using the 311 diffraction from Ni sub 3 Al with about 73...

  4. Plant Tissues in 3D via X-Ray Tomography: Simple Contrasting Methods Allow High Resolution Imaging

    OpenAIRE

    Yannick M Staedler; David Masson; Jürg Schönenberger

    2013-01-01

    Computed tomography remains strongly underused in plant sciences despite its high potential in delivering detailed 3D phenotypical information because of the low X-ray absorption of most plant tissues. Existing protocols to study soft tissues display poor performance, especially when compared to those used on animals. More efficient protocols to study plant material are therefore needed. Flowers of Arabidopsis thaliana and Marcgravia caudata were immersed in a selection of contrasting agents ...

  5. Model for electron emission of high-Z radio-sensitizing nanoparticle irradiated by X-rays

    OpenAIRE

    Casta, R.; Champeaux, J. -P.; Sence, M.; Moretto-Capelle, P.; Cafarelli, P.

    2014-01-01

    In this paper we develop a new model for the electron emission of high-Z nanoparticle irradiated by X-rays. This study is motivated by the recent advances about the nanoparticle enhancement of cancer treatment by radiotherapy. Our original approach combines a pure probabilistic analytical model for the photon trajectories inside the nanoparticle and subsequent electron cascade trajectories based here on a Monte-Carlo simulation provided by the Livermore model implemented in Geant4. To compare...

  6. Ultra high-speed x-ray imaging of laser-driven shock compression using synchrotron light

    Science.gov (United States)

    Olbinado, Margie P.; Cantelli, Valentina; Mathon, Olivier; Pascarelli, Sakura; Grenzer, Joerg; Pelka, Alexander; Roedel, Melanie; Prencipe, Irene; Laso Garcia, Alejandro; Helbig, Uwe; Kraus, Dominik; Schramm, Ulrich; Cowan, Tom; Scheel, Mario; Pradel, Pierre; De Resseguier, Thibaut; Rack, Alexander

    2018-02-01

    A high-power, nanosecond pulsed laser impacting the surface of a material can generate an ablation plasma that drives a shock wave into it; while in situ x-ray imaging can provide a time-resolved probe of the shock-induced material behaviour on macroscopic length scales. Here, we report on an investigation into laser-driven shock compression of a polyurethane foam and a graphite rod by means of single-pulse synchrotron x-ray phase-contrast imaging with MHz frame rate. A 6 J, 10 ns pulsed laser was used to generate shock compression. Physical processes governing the laser-induced dynamic response such as elastic compression, compaction, pore collapse, fracture, and fragmentation have been imaged; and the advantage of exploiting the partial spatial coherence of a synchrotron source for studying low-density, carbon-based materials is emphasized. The successful combination of a high-energy laser and ultra high-speed x-ray imaging using synchrotron light demonstrates the potentiality of accessing complementary information from scientific studies of laser-driven shock compression.

  7. Suppression of high-density artefacts in x-ray CT images using temporal digital subtraction with application to cryotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Baissalov, R.; Sandison, G.A.; Rewcastle, J.C. [Department of Medical Physics, Tom Baker Cancer Center, Calgary, Canada, T2N 4N2 2 Department of Physics and Astronomy, University of Calgary, Calgary T2N 2N4 (Canada); Donnelly, B.J. [Department of Surgery, Tom Baker Cancer Center, Calgary, Canada, T2N 4N2 4 Department of Surgery, Foothills Hospital, Calgary T2N 2T7 (Canada); Saliken, J.C. [Department of Surgery, Tom Baker Cancer Center, Calgary T2N 4N2 (Canada); Department of Diagnostic Imaging, Foothills Hospital, Calgary T2N 2T7 (Canada); McKinnon, J.G. [Department of Surgery, Foothills Hospital, Calgary T2N 2T7 (Canada); Muldrew, K. [Department of Surgery, Faculty of Medicine, University of Calgary, Calgary T2N 2T7 (Canada)

    2000-05-01

    Image guidance in cryotherapy is usually performed using ultrasound. Although not currently in routine clinical use, x-ray CT imaging is an alternative means of guidance that can display the full 3D structure of the iceball, including frozen and unfrozen regions. However, the quality of x-ray CT images is compromised by the presence of high-density streak artefacts. To suppress these artefacts we applied temporal digital subtraction (TDS). This TDS method has the added advantage of improving the grey-scale contrast between frozen and unfrozen tissue in the CT images. Two sets of CT images were taken of a phantom material, cryoprobes and a urethral warmer (UW) before and during the cryoprobe freeze cycle. The high-density artefacts persisted in both image sets. TDS was performed on these two image sets using the corresponding mask image of unfrozen material and the same geometrical configuration of the cryoprobes and the UW. The resultant difference image had a significantly reduced artefact content. Thus TDS can be used to significantly suppress or eliminate high-density CT streak artefacts without reducing the metallic content of the cryoprobes. In vivo study needs to be conducted to establish the utility of this TDS procedure for CT assisted prostate or liver cryotherapy. Applying TDS in x-ray CT guided cryotherapy will facilitate estimation of the number and location of all frozen and unfrozen regions, potentially making cryotherapy safer and less operator dependent. (author)

  8. Charge Dynamics in Low Dimensional Prototype Correlated Systems: A View with High-Energy X-rays

    Energy Technology Data Exchange (ETDEWEB)

    Hasan, Md-Zahid

    2002-03-20

    The electronic structure of Mott systems continues to be an unsolved problem in physics despite more than half-century of intense research efforts. Well-developed momentum-resolved spectroscopies such as photoemission and neutron scattering cannot directly address problems associated with the full Mott gap as angle-resolved photoemission probes the occupied states and neutrons do not couple to the electron's charge directly. Our observation of dispersive particle- hole pair excitations across the charge gap (effective Mott gap) in several low dimensional prototype Mott insulators using high resolution resonant inelastic x-ray scattering suggests that the excitations across the gap are highly anisotropic and momentum dependent. The results indirectly provide some information about the momentum dependence of unoccupied states in these correlated systems. The x-ray scattering results are complementary to the electron scattering results by the possibility of studying the excitations in the high momentum transfer regimes (near the zone boundaries and comers). This is also demonstrated in case of studying plasmons near the wave vector regime where Landau damping starts to dominate. X-ray scattering also allows one to probe the symmetry characters of localized electrons and the excitations through the strong polarization dependence of scattering near a core resonance. The study of charge-orbital localization is demonstrated in case of manganese oxides. Given its deeply bulk-sensitive and weak-coupling nature and the ability to probe dispersive behavior of charge fluctuations over several Brillouin zones, inelastic x-ray scattering shows the promise to become an important experimental tool to study the electronic structure of complex quantum systems.

  9. 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.

  10. Using X-ray Thomson Scattering to Characterize Highly Compressed, Near-Degenerate Plasmas at the NIF

    Science.gov (United States)

    Doeppner, Tilo; Kraus, D.; Neumayer, P.; Bachmann, B.; Divol, L.; Kritcher, A. L.; Landen, O. L.; Fletcher, L.; Glenzer, S. H.; Falcone, R. W.; MacDonald, M. J.; Saunders, A.; Witte, B.; Redmer, R.; Chapman, D.; Baggott, R.; Gericke, D. O.; Yi, S. A.

    2017-10-01

    We are developing x-ray Thomson scattering for implosion experiments at the National Ignition Facility to characterize plasma conditions in plastic and beryllium capsules near stagnation, reaching more than 20x compression and electron densities of 1025 cm-3, corresponding to a Fermi energy of 170 eV. Using a zinc He- α x-ray source at 9 keV, experiments at a large scattering angle of 120° measure non-collective scattering spectra with high sensitivity to K-shell ionization, and find higher charge states than predicted by widely used ionization models. Reducing the scattering angle to 30° probes the collective scattering regime with sensitivity to collisions and conductivity. We will discuss recent results and future plans. This work was performed under the auspices of the US Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

  11. High stability X-ray spectroscopy system with on-chip front-end in charge amplifier configuration

    Energy Technology Data Exchange (ETDEWEB)

    Guazzoni, Chiara; Chiesa, Marco; Sampietro, Marco E-mail: marco.sampietro@polimi.it; Lechner, Peter

    2003-10-11

    This paper presents the performance of a two-chip detector system based on a silicon drift detector and on a charge amplifier, part of the latter being integrated in the detector chip. The two-chip system is intended for high-resolution X-ray spectroscopy experiments in which stability of operation is mandatory to avoid on-line calibration procedures. Experimental measurements have been carried out to test the stability of the whole system with a quantitative analysis of the gain stability obtained by comparing X-ray spectra taken at different operating conditions, varying the temperature and/or the detector bias. A gain variation of less than 0.4% has been obtained at extreme operating conditions. The problems and critical aspects of the two-chip charge amplifier solution are discussed.

  12. Quantifying the Nucleation and Growth Kinetics of Microwave Nanochemistry Enabled by in Situ High-Energy X-ray Scattering.

    Science.gov (United States)

    Liu, Qi; Gao, Min-Rui; Liu, Yuzi; Okasinski, John S; Ren, Yang; Sun, Yugang

    2016-01-13

    The fast reaction kinetics presented in the microwave synthesis of colloidal silver nanoparticles was quantitatively studied, for the first time, by integrating a microwave reactor with in situ X-ray diffraction at a high-energy synchrotron beamline. Comprehensive data analysis reveals two different types of reaction kinetics corresponding to the nucleation and growth of the Ag nanoparticles. The formation of seeds (nucleation) follows typical first-order reaction kinetics with activation energy of 20.34 kJ/mol, while the growth of seeds (growth) follows typical self-catalytic reaction kinetics. Varying the synthesis conditions indicates that the microwave colloidal chemistry is independent of concentration of surfactant. These discoveries reveal that the microwave synthesis of Ag nanoparticles proceeds with reaction kinetics significantly different from the synthesis present in conventional oil bath heating. The in situ X-ray diffraction technique reported in this work is promising to enable further understanding of crystalline nanomaterials formed through microwave synthesis.

  13. High-Resolution X-Ray Spectroscopy of the Galactic Supernova Remnant Puppis A with the XMM-Newton RGS

    Science.gov (United States)

    Katsuda, Satoru; Tsunemi, Hiroshi; Mori, Koji; Uchida, Hiroyuki; Petre, Robert; Yamada, Shinya; Akamatsu, Hiroki; Konami, Saori; Tamagawa, Toru

    2012-01-01

    We present high-resolution X-ray spectra of cloud-shock interaction regions in the eastern and northern rims of the Galactic supernova remnant Puppis A, using the Reflection Grating Spectrometer onboard the XMM-Newton satellite. A number of emission lines including K(alpha) triplets of He-like N, O , and Ne are clearly resolved for the first time. Intensity ratios of forbidden to resonance lines in the triplets are found to be higher than predictions by thermal emission models having plausible plasma parameters. The anomalous line ratios cannot be reproduced by effects of resonance scattering, recombination, or inner-shell ionization processes, but could be explained by charge-exchange emission that should arise at interfaces between the cold/warm clouds and the hot plasma. Our observations thus provide observational support for charge-exchange X-ray emission in supernova remnants.

  14. High spatial resolution grain orientation and strain mapping in thin films using polychromatic submicron X-ray diffraction

    Energy Technology Data Exchange (ETDEWEB)

    Tamura, N.; MacDowell, A.A.; Celestre, R.S.; Padmore, H.A.; Valek, B.C.; Bravman, J.C.; Spolenak, R.; Brown, W.L.; Marieb, T.; Fujimoto, H.; Batterman, B.W.; Patel, J.R.

    2002-03-26

    The availability of high brilliance synchrotron sources, coupled with recent progress in achromatic focusing optics and large area 2D detector technology, have allowed us to develop an X-ray synchrotron technique capable of mapping orientation and strain/stress in polycrystalline thin films with submicron spatial resolution. To demonstrate the capabilities of this instrument, we have employed it to study the microstructure of aluminum thin film structures at the granular and subgranular level. Owing to the relatively low absorption of X-rays in materials, this technique can be used to study passivated samples, an important advantage over most electron probes given the very different mechanical behavior of buried and unpassivated materials.

  15. High Spatial Resolution Grain Orientation and Strain Mapping in Thin Films using Polychromatic Submicron X-ray Diffraction

    Energy Technology Data Exchange (ETDEWEB)

    Patel, Jamshed R.

    2002-06-14

    The availability of high brilliance synchrotron sources, coupled with recent progress in achromatic focusing optics and large area 2D detector technology, have allowed us to develop a X-ray synchrotron technique capable of mapping orientation and strain/stress in polycrystalline thin films with submicron spatial resolution. To demonstrate the capabilities of this instrument, we have employed it to study the microstructure of aluminum thin film structures at the granular and subgranular level. Owing to the relatively low absorption of X-rays in materials, this technique can be used to study passivated samples, an important advantage over most electron probes given the very different mechanical behavior of buried and unpassivated materials.

  16. Dynamic Characterizations of an 8-frame Half-Strip High-speed X-ray Microchannel Plate Imager

    Energy Technology Data Exchange (ETDEWEB)

    Ken Moy, Ming Wu, Craig Kruschwitz, Aric Tibbits, Matt Griffin, Greg Rochau

    2008-09-05

    High-speed microchannel plate (MCP)–based imagers are critical detectors for x-ray diagnostics employed on Z-experiments at Sandia National Laboratories (SNL) to measure time-resolved x-ray spectra and to image dynamic hohlraums. A multiframe design using eight half strips in one imager permits recordings of radiation events in discrete temporal snapshots to yield a time-evolved movie. We present data using various facilities to characterize the performance of this design. These characterization studies include DC and pulsed-voltage biased measurements in both saturated and linear operational regimes using an intense, short-pulsed UV laser. Electrical probe measurements taken to characterize the shape of the HV pulse propagating across the strips help to corroborate the spatial gain dependence.

  17. A novel technique combining high-resolution synchrotron x-ray microtomography and x-ray diffraction for characterization of micro particulates

    Science.gov (United States)

    Merrifield, David R.; Ramachandran, Vasuki; Roberts, Kevin J.; Armour, Wesley; Axford, Danny; Basham, Mark; Connolley, Thomas; Evans, Gwyndaf; McAuley, Katherine E.; Owen, Robin L.; Sandy, James

    2011-11-01

    The processing of solids, such as crystals, is strongly influenced by the surface properties of the material. In recent years the pharmaceutical industry has shown great interest in identifying, or chemically speciating, the molecular components of crystal faces. Formerly, characterization of the molecular identity of crystal faces was restricted to the study of large single crystals. This would have been primarily for structure determination as part of the drug registration process. Diamond Light Source in Oxfordshire is a new synchrotron facility in the UK, having 18 operational beamlines with 4 more in the construction phase. Beamlines at this medium energy light source enable the study of micron-sized objects in great detail. It is well known that x-ray microtomography (XMT) can be used to investigate the external morphology of a crystal whereas x-ray diffraction (XRD) is used to study the molecular orientation, structure and packing within the crystal. The objective of this research is to assess the feasibility of, and thereby develop a new methodology for, characterizing the molecular identity of a particular face of a crystalline particle at a scale of scrutiny of 20-50 µm by combining these two powerful techniques. This work demonstrates the application of XMT and XRD to investigate respectively the shape and crystalline phase/orientation of relevant test crystals. This research has applications in the pharmaceutical industry in that when the exact molecular nature of a particular face is known, the important physico-pharmaceutical properties stemming from that can be better understood. Some initial data are presented and discussed.

  18. X-Raying the Beating Heart of a Newborn Star: Rotational Modulation of High-Energy Radiation from V1647 Ori

    Science.gov (United States)

    Hamaguchi, Kenji; Grosso, Nicolas; Kastner, Joel H.; Weintraub, David A.; Richmond, Michael; Petre, Robert; Teets, William K.; Principe, David

    2012-01-01

    We report a periodicity of approx.1 day in the highly elevated X-ray emission from the protostar V1647 Ori during its two recent multiple-year outbursts of mass accretion. This periodicity is indicative of protostellar rotation at near-breakup speed. Modeling of the phased X-ray light curve indicates the high-temperature ( 50 MK), X-ray-emitting plasma, which is most likely heated by accretion-induced magnetic reconnection, resides in dense ( 5 1010 cm.3), pancake-shaped magnetic footprints where the accretion stream feeds the newborn star. The sustained X-ray periodicity of V1647 Ori demonstrates that such protostellar magnetospheric accretion configurations can be stable over timescales of years. Subject headings: stars: formation stars: individual (V1647 Ori) stars: pre-main sequence X-rays: stars

  19. Single-shot structural analysis by high-energy X-ray diffraction using an ultrashort all-optical source.

    Science.gov (United States)

    Rakowski, R; Golovin, G; O'Neal, J; Zhang, J; Zhang, P; Zhao, B; Wilson, M D; Veale, M C; Seller, P; Chen, S; Banerjee, S; Umstadter, D; Fuchs, M

    2017-11-30

    High-energy X-rays (HEX-rays) with photon energies on order of 100 keV have attractive characteristics, such as comparably low absorption, high spatial resolution and the ability to access inner-shell states of heavy atoms. These properties are advantageous for many applications ranging from studies of bulk materials to the investigation of materials in extreme conditions. Ultrafast X-ray diffraction allows the direct imaging of atomic dynamics simultaneously on its natural time and length scale. However, using HEX-rays for ultrafast studies has been limited due to the lack of sources that can generate pulses of sufficiently short (femtosecond) duration in this wavelength range. Here we show single-crystal diffraction using ultrashort ~90 keV HEX-ray pulses generated by an all-optical source based on inverse Compton scattering. We also demonstrate a method for measuring the crystal lattice spacing in a single shot that contains only ~105 photons in a spectral bandwidth of ~50% full width at half maximum (FWHM). Our approach allows us to obtain structural information from the full X-ray spectrum. As target we use a cylindrically bent Ge crystal in Laue transmission geometry. This experiment constitutes a first step towards measurements of ultrafast atomic dynamics using femtosecond HEX-ray pulses.

  20. Measuring device for synchrotron X-ray imaging and first results of high temperature polymer electrolyte membrane fuel cells

    Science.gov (United States)

    Kuhn, R.; Scholta, J.; Krüger, Ph.; Hartnig, Ch.; Lehnert, W.; Arlt, T.; Manke, I.

    In this paper, a measurement cell for recording synchrotron X-ray images of low and high temperature PEM fuel cells is described. The experimental setup allows for recording of cross-sectional images, as well as for radiograms in through-plane direction, with limited signal degradation. First results on H 3PO 4 concentration and distribution as a function of the operating conditions are presented. This basic cell design is optimized for liquid water detection. To visualize water in an operating cell the energy of the synchrotron X-ray beam has been chosen in a range between 7 and 30 keV where high resolution images can be obtained. The cell design is described in detail, and references to results obtained with LT-PEMFC applications focusing on liquid water evolution are given. For HT-PEMFC applications, the method of synchrotron X-ray imaging can provide an insight on electrolyte concentration and distribution. These investigations show that significant information can be collected on electrolyte distribution and concentration as a function of operating parameters such as temperature, media utilization and humidification degree. First results for the dependence of electrolyte distribution on operating conditions are presented.

  1. Synergistic assembly of heavy metal clusters and luminescent organic bridging ligands in metal-organic frameworks for highly efficient X-ray scintillation.

    Science.gov (United States)

    Wang, Cheng; Volotskova, Olga; Lu, Kuangda; Ahmad, Moiz; Sun, Conroy; Xing, Lei; Lin, Wenbin

    2014-04-30

    We have designed two metal-organic frameworks (MOFs) to efficiently convert X-ray to visible-light luminescence. The MOFs are constructed from M6(μ3-O)4(μ3-OH)4(carboxylate)12 (M = Hf or Zr) secondary building units (SBUs) and anthracene-based dicarboxylate bridging ligands. The high atomic number of Zr and Hf in the SBUs serves as effective X-ray antenna by absorbing X-ray photons and converting them to fast electrons through the photoelectric effect. The generated electrons then excite multiple anthracene-based emitters in the MOF through inelastic scattering, leading to efficient generation of detectable photons in the visible spectrum. The MOF materials thus serve as efficient X-ray scintillators via synergistic X-ray absorption by the metal-cluster SBUs and optical emission by the bridging ligands.

  2. Synergistic Assembly of Heavy Metal Clusters and Luminescent Organic Bridging Ligands in Metal–Organic Frameworks for Highly Efficient X-ray Scintillation

    Science.gov (United States)

    2015-01-01

    We have designed two metal–organic frameworks (MOFs) to efficiently convert X-ray to visible-light luminescence. The MOFs are constructed from M6(μ3-O)4(μ3-OH)4(carboxylate)12 (M = Hf or Zr) secondary building units (SBUs) and anthracene-based dicarboxylate bridging ligands. The high atomic number of Zr and Hf in the SBUs serves as effective X-ray antenna by absorbing X-ray photons and converting them to fast electrons through the photoelectric effect. The generated electrons then excite multiple anthracene-based emitters in the MOF through inelastic scattering, leading to efficient generation of detectable photons in the visible spectrum. The MOF materials thus serve as efficient X-ray scintillators via synergistic X-ray absorption by the metal-cluster SBUs and optical emission by the bridging ligands. PMID:24730683

  3. High Resolution X-ray Characterization Of Mosaic Crystals For Hard X- And Gamma-ray Astronomy

    Science.gov (United States)

    Marchini, L.; Ferrari, C.; Buffagni, E.; Zappettini, A.

    2011-09-01

    For hard X-ray astronomy in the 70-1000 keV energy range Laue lenses have been proposed where the focusing elements are made of single mosaic crystals, in order to increase the diffraction efficiency with respect to perfect crystals. Suitable crystals to be used for such application should have a sufficient density to increase the diffraction efficiency and a mosaicity ranging between 30 arcsec and 1-2 arcmin, depending on the lens focusing distance and resolution. In the past germanium and copper crystals, often employed as monochromators for neutrons, have been considered. In this work we propose several crystalline materials of different degree of crystal perfection such as GaAs, Cu, CdTe, and CdZnTe as possible mosaic crystals for hard X-ray astronomy. They were analyzed by high resolution X-ray diffraction at 8 keV and by diffraction at energies up to 700 keV at synchrotron. It was found that: CdTe and CdZnTe crystals exhibit low angle grain boundaries preventing the formation of a single diffracted X-ray beam; Cu crystals exhibit mosaicity of the order of several arcmin, however a deep etching is needed to remove the cutting damage; GaAs crystals grown by LEC method show mosaicity between 15 and 30 arcsec and good diffraction efficiency up to energies of 700 keV. Annealing and surface damage were considered as possible methods to increase the GaAs crystal mosaicity.

  4. Zernike phase contrast in high-energy x-ray transmission microscopy based on refractive optics.

    Science.gov (United States)

    Falch, Ken Vidar; Lyubomirsky, Mikhail; Casari, Daniele; Snigirev, Anatoly; Snigireva, Irina; Detlefs, Carsten; Michiel, Marco Di; Lyatun, Ivan; Mathiesen, Ragnvald H

    2018-01-01

    The current work represents the first implementation of Zernike phase contrast for compound refractive lens based x-ray microscopy, and also the first successful Zernike phase contrast experiment at photon energies above 12 keV. Phase contrast was achieved by fitting a compound refractive lens with a circular phase plate. The resolution is demonstrated to be sub-micron, and can be improved using already existing technology. The possibility of combining the technique with polychromatic radiation is considered, and a preliminary test experiment was performed with positive results. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Direct Polishing of Full-Shell, High-Resolution X-Ray Optics

    Science.gov (United States)

    Roche, Jacqueline M.; Gubarev, Mikhail V.; Smith, W. Scott; O'Dell, Stephen L.; Kolodziejczak, Jeffrey J.; Weisskopf, Martin C.; Ramsey, Brian D.; Elsner, Ronald F.

    2014-01-01

    Future x-ray telescopes will likely require lightweight mirrors to attain the large collecting areas needed to accomplish the science objectives. Understanding and demonstrating processes now is critical to achieving sub-arcsecond performance in the future. Consequently, designs not only of the mirrors but of fixtures for supporting them during fabrication, metrology, handling, assembly, and testing must be adequately modeled and verified. To this end, MSFC is using finite-element modeling to study the effects of mounting on thin, full-shell grazing-incidence mirrors, during all processes leading to a flight.

  6. High aspect ratio metal microcasting by hot embossing for X-ray optics fabrication

    OpenAIRE

    Romano, Lucia; Vila-Comamala, Joan; Kagias, Matias; Vogelsang, Konrad; Schift, Helmut; Stampanoni, Marco; Jefimovs, Konstantins

    2017-01-01

    Metal microstructured optical elements for grating-based X-ray phase-contrast interferometry were fabricated by using an innovative approach of microcasting: hot embossing technology with low melting temperature (280{\\deg}C) metal alloy foils and silicon etched templates. A gold-tin alloy (80w%Au / 20w%Sn) was used to cast micro-gratings with pitch sizes in the range of 2 to 20 micrometers and depth of the structures up to 80 micrometers. The metal filling of the silicon template strongly dep...

  7. In situ X-ray diffraction environments for high-pressure reactions

    DEFF Research Database (Denmark)

    R. S. Hansen, Bjarne; Møller, Kasper Trans; Paskevicius, Mark

    2015-01-01

    New sample environments and techniques specifically designed for in situ powder X-ray diffraction studies up to 1000 bar (1 bar = 105 Pa) gas pressure are reported and discussed. The cells can be utilized for multiple purposes in a range of research fields. Specifically, investigations of gas......–solid reactions and sample handling under inert conditions are undertaken here. Sample containers allowing the introduction of gas from one or both ends are considered, enabling the possibility of flow-through studies. Various containment materials are evaluated, e.g. capillaries of single-crystal sapphire (Al2O3...

  8. Characterization and modeling of transition edge sensors for high resolution X-ray calorimeter arrays

    Energy Technology Data Exchange (ETDEWEB)

    Saab, T. E-mail: tsaab@milkyway.gsfc.nasa.gov; Apodacas, E.; Bandler, S.R.; Boyce, K.; Chervenak, J.; Figueroa-Feliciano, E.; Finkbeiner, F.; Hammock, C.; Kelley, R.; Lindeman, M.; Porter, F.S.; Stahle, C.K

    2004-03-11

    Characterizing and understanding, in detail, the behavior of a Transition Edge Sensor (TES) is required for achieving an energy resolution of 2 eV at 6 keV desired for future X-ray observatory missions. This paper will report on a suite of measurements (e.g. impedance and I-V among others) and simulations that were developed to extract a comprehensive set of TES parameters such as heat capacity, thermal conductivity, and R(T,I), {alpha}(T,I), and {beta}{sub i}(T,I) surfaces. These parameters allow for the study of the TES calorimeter behavior at and beyond the small signal regime.

  9. A High Position Resolution X-ray Detector: an Edge on Illuminated Capillary Plate Combined with a Gas Amplification Structure

    CERN Document Server

    Iacobaeus, C.; Lund-Jensen, B.; Ostling, J.; Pavlopoulos, P.; Peskov, V.; Tokanai, F.

    2006-01-01

    We have developed and successfully tested a prototype of a new type of high position resolution hybrid X-ray detector. It contains a thin wall lead glass capillary plate converter of X-rays combined with a microgap parallel-plate avalanche chamber filled with gas at 1 atm. The operation of these converters was studied in a wide range of X-ray energies (from 6 to 60 keV) at incident angles varying from 0-90 degree. The detection efficiency, depending on the geometry, photon energy, incident angle and the mode of operation, was between 5-30 percent in a single step mode and up to 50 percent in a multi-layered combination. Depending on the capillary geometry, the position resolution achieved was between 0.050-0.250 mm in digital form and was practically independent of the photon energy or gas mixture. The usual lead glass capillary plates operated without noticeable charging up effects at counting rates of 50 Hz/mm2, and hydrogen treated capillaries up to 10E5 Hz/mm2. The developed detector may open new possibil...

  10. High-resolution soft X-ray spectroscopy of 2.3 keV/u N sup 7 sup + ions through a microcapillary target

    CERN Document Server

    Iwai, Y; Kanai, Y; Oyama, H; Ando, K; Masuda, H; Nishio, K; Nakao, M; Tamamura, T; Komaki, K; Yamazaki, Y

    2002-01-01

    X-rays emitted from 2.3 keV/u sup 1 sup 5 N sup 7 sup + ions transmitted through a highly ordered Ni microcapillary were measured with a high-resolution soft X-ray spectrometer. The highly ordered microcapillary has recently become available employing a nano-lithographic technique. A transmission ratio and charge state distribution of ions through the microcapillary target were found to be consistent with theoretical predictions. A preliminary analysis showed that a series of X-rays from np-1s transitions with n as high as 8 were identified, which is consistent with the classical over barrier model.

  11. CALIBRATION OF THE NuSTAR HIGH-ENERGY FOCUSING X-RAY TELESCOPE

    Energy Technology Data Exchange (ETDEWEB)

    Madsen, Kristin K.; Harrison, Fiona A.; Grefenstette, Brian W.; Miyasaka, Hiromasa; Forster, Karl; Fuerst, Felix; Rana, Vikram; Walton, Dominic J. [Cahill Center for Astronomy and Astrophysics, California Institute of Technology, Pasadena, CA 91125 (United States); Markwardt, Craig B. [Goddard Space Flight Center, Greenbelt, MD 20771 (United States); An, Hongjun [Department of Physics, McGill University, Montreal, Quebec, H3A 2T8 (Canada); Bachetti, Matteo [Université de Toulouse, UPS-OMP, IRAP, Toulouse (France); Kitaguchi, Takao [RIKEN, 2-1 Hirosawa, Wako, Saitama, 351-0198 (Japan); Bhalerao, Varun [Inter-University Center for Astronomy and Astrophysics, Post Bag 4, Ganeshkhind, Pune 411007 (India); Boggs, Steve; Craig, William W. [Space Sciences Laboratory, University of California, Berkeley, CA 94720 (United States); Christensen, Finn E. [DTU Space, National Space Institute, Technical University of Denmark, Elektronvej 327, DK-2800 Lyngby (Denmark); Hailey, Charles J. [Columbia Astrophysics Laboratory, Columbia University, NY 10027 (United States); Perri, Matteo; Puccetti, Simonetta [ASI Science Data Center, via Galileo Galilei, I-00044, Frascati (Italy); Stern, Daniel [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States); and others

    2015-09-15

    We present the calibration of the Nuclear Spectroscopic Telescope Array (NuSTAR) X-ray satellite. We used the Crab as the primary effective area calibrator and constructed a piece-wise linear spline function to modify the vignetting response. The achieved residuals for all off-axis angles and energies, compared to the assumed spectrum, are typically better than ±2% up to 40 keV and 5%–10% above due to limited counting statistics. An empirical adjustment to the theoretical two-dimensional point-spread function (PSF) was found using several strong point sources, and no increase of the PSF half-power diameter has been observed since the beginning of the mission. We report on the detector gain calibration, good to 60 eV for all grades, and discuss the timing capabilities of the observatory, which has an absolute timing of ±3 ms. Finally, we present cross-calibration results from two campaigns between all the major concurrent X-ray observatories (Chandra, Swift, Suzaku, and XMM-Newton), conducted in 2012 and 2013 on the sources 3C 273 and PKS 2155-304, and show that the differences in measured flux is within ∼10% for all instruments with respect to NuSTAR.

  12. The nuclear spectroscopic telescope array (NuSTAR) high-energy X-ray mission

    DEFF Research Database (Denmark)

    Harrison, Fiona A.; Craig, William W.; Christensen, Finn Erland

    2013-01-01

    of sensitivity and spatial and spectral resolution, NuSTAR will pursue five primary scientific objectives: (1) probe obscured active galactic nucleus (AGN) activity out to the peak epoch of galaxy assembly in the universe (at z ≲ 2) by surveying selected regions of the sky; (2) study the population of hard X......-ray-emitting compact objects in the Galaxy by mapping the central regions of the Milky Way; (3) study the non-thermal radiation in young supernova remnants, both the hard X-ray continuum and the emission from the radioactive element 44Ti; (4) observe blazars contemporaneously with ground-based radio, optical, and Te......V telescopes, as well as with Fermi and Swift , to constrain the structure of AGN jets; and (5) observe line and continuum emission from core-collapse supernovae in the Local Group, and from nearby Type Ia events, to constrain explosion models. During its baseline two-year mission, NuSTAR will also undertake...

  13. From EXOSAT to the High Energy Astrophysics Science Archive (HEASARC): X-ray Astronomy Comes of Age

    Science.gov (United States)

    White, Nicholas E.

    2012-01-01

    In May 1983 the European Space Agency launched EXOSAT, its first X-ray astronomy observatory. Even though it lasted only 3 short years, this mission brought not only new capabilities that resulted in unexpected discoveries, but also a pioneering approach to operations and archiving that changed X-ray astronomy from observations led by small instrument teams, to an observatory approach open to the entire community through a guest observer program. The community use of the observatory was supported by a small dedicated team of scientists, the precursor to the data center activities created to support e.g. Chandra and XMM-Newton. The new science capabilities of EX OS AT included a 90 hr highly eccentric high earth orbit that allow unprecedented continuous coverage of sources as well as direct communication with the satellite that allowed real time decisions to respond to unexpected events through targets of opportunity. The advantages of this orbit demonstrated by EXOSAT resulted in Chandra and XMM-Newton selecting similar orbits. The three instruments on board the EXOSAT observatory were complementary, designed to give complete coverage over a wide energy band pass of 0.05-50 keY. An onboard processor could be programmed to give multiple data modes that could be optimized in response to science discoveries: These new capabilities resulted in many new discoveries including the first comprehensive study of AGN variability, new orbital periods in X-ray binaries and cataclysmic variables, new black holes, quasi-periodic oscillations from neutron stars and black holes and broad band X-ray spectroscopy. The EXOSAT team generated a well-organized database accessible worldwide over the nascent internet, allowing remote selection of data products, making samples and undertaking surveys from the data. The HEASARC was established by NASA at Goddard Space Flight Center in 1990 as the repository of NASA X-ray and Gamma-ray data. The proven EXOSAT database system became the core

  14. From EXOSAT to the High Energy Astrophysics Science Archive (HEASARC): X-ray Astronomy Comes of Age

    Science.gov (United States)

    White, Nicholas E.

    2013-01-01

    In May 1983 the European Space Agency launched EXOSAT, its first X-ray astronomy observatory. Even though it lasted only 3 short years, this mission brought not only new capabilities that resulted in unexpected discoveries, but also a pioneering approach to operations and archiving that changed X-ray astronomy from observations led by small instrument teams, to an observatory approach open to the entire community through a guest observer program. The community use of the observatory was supported by a small dedicated team of scientists, the precursor to the data center activities created to support e.g. Chandra and XMM-Newton. The new science capabilities of EXOSAT included a 90 hr highly eccentric high earth orbit that allow unprecedented continuous coverage of sources as well as direct communication with the satellite that allowed real time decisions to respond to unexpected events through targets of opportunity. The advantages of this orbit demonstrated by EXOSAT resulted in Chandra and XMM-Newton selecting similar orbits. The three instruments on board the EXOSAT observatory were complementary, designed to give complete coverage over a wide energy band pass of 0.05-50 keV. An onboard processor could be programed to give multiple data modes that could be optimized in response to science discoveries. These new capabilities resulted in many new discoveries including the first comprehensive study of AGN variability, new orbital periods in X-ray binaries and cataclysmic variables, new black holes, quasi-periodic oscillations from neutron stars and black holes and broad band X-ray spectroscopy. The EXOSAT team generated a well-organized database accessible worldwide over the nascent internet, allowing remote selection of data products, making samples and undertaking surveys from the data. The HEASARC was established by NASA at Goddard Space Flight Center in 1990 as the repository of NASA X-ray and Gamma-ray data. The proven EXOSAT database system became the core of

  15. Characterizing high energy spectra of NIF ignition Hohlraums using a differentially filtered high energy multipinhole x-ray imager.

    Science.gov (United States)

    Park, Hye-Sook; Dewald, E D; Glenzer, S; Kalantar, D H; Kilkenny, J D; MacGowan, B J; Maddox, B R; Milovich, J L; Prasad, R R; Remington, B A; Robey, H F; Thomas, C A

    2010-10-01

    Understanding hot electron distributions generated inside Hohlraums is important to the national ignition campaign for controlling implosion symmetry and sources of preheat. While direct imaging of hot electrons is difficult, their spatial distribution and spectrum can be deduced by detecting high energy x-rays generated as they interact with target materials. We used an array of 18 pinholes with four independent filter combinations to image entire Hohlraums with a magnification of 0.87× during the Hohlraum energetics campaign on NIF. Comparing our results with Hohlraum simulations indicates that the characteristic 10-40 keV hot electrons are mainly generated from backscattered laser-plasma interactions rather than from Hohlraum hydrodynamics.

  16. Chest X-Ray

    Medline Plus

    Full Text Available ... the most commonly performed x-ray exams and use a very small dose of ionizing radiation to ... to your health. While a chest x-ray use a tiny dose of ionizing radiation, the benefit ...

  17. 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.

  18. Antibodies under pressure: A Small-Angle X-ray Scattering study of Immunoglobulin G under high hydrostatic pressure.

    Science.gov (United States)

    König, Nico; Paulus, Michael; Julius, Karin; Schulze, Julian; Voetz, Matthias; Tolan, Metin

    2017-05-26

    In the present work two subclasses of the human antibody Immunoglobulin G (IgG) have been investigated by Small-Angle X-ray Scattering under high hydrostatic pressures up to 5kbar. It is shown that IgG adopts a symmetric T-shape in solution which differs significantly from available crystal structures. Moreover, high-pressure experiments verify the high stability of the IgG molecule. It is not unfolded by hydrostatic pressures of up to 5kbar but a slight increase of the radius of gyration was observed at elevated pressures. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Monochromatic Mammographic Imaging Using X-ray Polycapillary Optics

    National Research Council Canada - National Science Library

    Sugiro, Francisca

    2000-01-01

    .... Monochromatic x rays can be used to produce higher contrast images. Polycapillary x-ray optics technology can produce a highly parallel, monochromatic, x-ray beam from a conventional radiographic source...

  20. Hand x-ray

    Science.gov (United States)

    X-ray - hand ... A hand x-ray is taken in a hospital radiology department or your health care provider's office by an ... technician. You will be asked to place your hand on the x-ray table, and keep it ...