WorldWideScience

Sample records for high-resolution x-ray spectra

  1. 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...... successfully in terms of the many-body theory of Mahan, Nozières, and De Dominicis. The 4d spectrum agrees well with predictions based on a relativistic-augmented-plane-wave band-structure calculation....

  2. 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)

  3. High resolution krypton M/sub 4,5/ x-ray emission spectra

    International Nuclear Information System (INIS)

    Perera, R.C.C.; Hettrick, M.C.; Lindle, D.W.

    1987-10-01

    High resolution M/sub 4,5/ (3d → 4p) x-ray emission spectra from a krypton plasma were measured using a recently developed grazing-incidence reflection-grating monochromator/spectrometer with very high flux rates at extreme ultraviolet and soft x-ray wave lengths. The nominal resolving power of the instrument, E/ΔE, is about 300 in this energy range (∼80 eV). Three dipole-allowed 3d → 4p emission lines were observed at 80.98 eV, 80.35 eV and 79.73 eV. A broad peak at about 82.3 eV is tentatively assigned to transitions resulting from Kr 2+ , and effects of excitation energy on M/sub 4,5/ x-ray emission were observed. 9 refs., 3 figs., 1 tab

  4. High-resolution measurements of x rays from ion-atom collisions

    International Nuclear Information System (INIS)

    Knudson, A.R.

    1974-01-01

    High resolution measurements of K x-ray spectra produced by ion-atom collisions at MeV energies are presented. These measurements indicate that a distribution of L-shell vacancies accompanies K-shell excitation. The variation of these spectra as a function of incident ion energy and atomic number is discussed. Difficulties in the analysis of these spectra due to rearrangement of vacancies between the time of the collision and the time of x-ray emission are considered. The use of high resolution x-ray measurements to obtain information on projectile ion vacancy configurations is demonstrated by data for Ar ions in KCl. X-ray spectra from Al projectiles in a variety of targets were measured and the effect of target composition on these spectra is discussed

  5. Analysis of X-ray Spectra of High-Z Elements obtained on Nike with high spectral and spatial resolution

    Science.gov (United States)

    Aglitskiy, Yefim; Weaver, J. L.; Karasik, M.; Serlin, V.; Obenschain, S. P.; Ralchenko, Yu.

    2014-10-01

    The spectra of multi-charged ions of Hf, Ta, W, Pt, Au and Bi have been studied on Nike krypton-fluoride laser facility with the help of two kinds of X-ray spectrometers. First, survey instrument covering a spectral range from 0.5 to 19.5 angstroms which allows simultaneous observation of both M- and N- spectra of above mentioned elements with high spectral resolution. Second, an imaging spectrometer with interchangeable spherically bent Quartz crystals that added higher efficiency, higher spectral resolution and high spatial resolution to the qualities of the former one. Multiple spectral lines with X-ray energies as high as 4 keV that belong to the isoelectronic sequences of Fe, Co, Ni, Cu and Zn were identified with the help of NOMAD package developed by Dr. Yu. Ralchenko and colleagues. In our continuous effort to support DOE-NNSA's inertial fusion program, this campaign covered a wide range of plasma conditions that result in production of relatively energetic X-rays. Work supported by the US DOE/NNSA.

  6. 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.

  7. HIGH-RESOLUTION X-RAY SPECTRA OF THE SYMBIOTIC STAR SS73 17

    International Nuclear Information System (INIS)

    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 Kα 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.

  8. 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

  9. 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

  10. 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

  11. X-ray fluorescence in Member States (Italy): Full field X-ray fluorescence imaging with high-energy and high-spatial resolution

    Energy Technology Data Exchange (ETDEWEB)

    Romano, F. P.; Masini, N.; Pappalardo, L., E-mail: romanop@lns.infn.it [IBAM, CNR, Via Biblioteca 4, 95124 Catania (Italy); Cosentino, L.; Gammino, S.; Mascali, D.; Rizzo, F. [INFN-LNS, Via S. Sofia 62, 95123 Catania (Italy)

    2014-02-15

    A full field X-ray camera for the X-Ray Fluorescence imaging of materials with high-energy and high-spatial resolution was designed and developed. The system was realized by coupling a pinhole collimator with a positionsensitive CCD detector. X-Ray fluorescence is induced on the samples by irradiation with an external X-ray tube. The characteristic X-ray spectra of the investigated materials are obtained by using a multi-frames acquisition in single-photon counting. The energy resolution measured at the Fe-Kα line was 157 eV. The spatial resolution of the system was determined by the analysis of a sharp-edge at different magnification values; it was estimated to be 90 μm at a magnification value of 3.2x and 190 μm at 0.8x. The present set-up of the system is suited to analyze samples with dimensions up to 5x4 cm{sup 2}. Typical measurement time is in the range between 1h to 4 h. (author)

  12. High-resolution X-ray television and high-resolution video recorders

    International Nuclear Information System (INIS)

    Haendle, J.; Horbaschek, H.; Alexandrescu, M.

    1977-01-01

    The improved transmission properties of the high-resolution X-ray television chain described here make it possible to transmit more information per television image. The resolution in the fluoroscopic image, which is visually determined, depends on the dose rate and the inertia of the television pick-up tube. This connection is discussed. In the last few years, video recorders have been increasingly used in X-ray diagnostics. The video recorder is a further quality-limiting element in X-ray television. The development of function patterns of high-resolution magnetic video recorders shows that this quality drop may be largely overcome. The influence of electrical band width and number of lines on the resolution in the X-ray television image stored is explained in more detail. (orig.) [de

  13. The high energy X-ray spectra of supernova remnants

    Science.gov (United States)

    Pravdo, S. H.; Nugent, J. J.

    The results of fitting an ionization-nonequilibrium (INE) model to the high-energy (above 5-keV) X-ray spectra of the young supernova remnants Cas A and Tycho are presented. As an additional constraint, the models must simultaneously fit lower-energy, higher-resolution data. For Cas A, a single INE component cannot adequately reproduce the features for the entire X-ray spectrum because the ionization structure of iron ions responsible for the K emission is inconsistent with that of the ions responsible for the lower-energy lines, and the flux of the highest-energy X-rays is underestimated. The iron K line and the high-energy continuum could arise from the same INE component, but the identification of this component with either the blast wave or the ejecta in the standard model is difficult. In Tycho, the high-energy data rule out a class of models for the lower-energy data which have too large a continuum contribution.

  14. High resolution X-ray spectroscopy of laser generated plasmas

    International Nuclear Information System (INIS)

    Faenov, A.Ya.; Skobelev, I.Yu.; Rosmej, F.B.

    1999-01-01

    The application of recently developed spectroscopic instruments in laser produced plasmas with simultaneous high spectral and spatial resolution combined with high luminosity discovered new types of X-ray spectra. These new types are characterised by the disappearance of the resonance lines and the strong emission of dielectronic satellite spectra. Several types of transitions of highly charged ions are discovered which are unknown from usual sources employed in atomic physics. New theoretical models are developed and successfully applied for the interpretation and for plasma diagnostics. (orig.)

  15. High resolution X-ray spectroscopy of laser generated plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Faenov, A.Ya.; Skobelev, I.Yu. [Multicharged Ions Spectra Data Center of VNIIFTRI, Mendeleevo (Russian Federation); Rosmej, F.B. [Technische Hochschule Darmstadt (Germany). Inst. fuer Kernphysik

    1999-11-01

    The application of recently developed spectroscopic instruments in laser produced plasmas with simultaneous high spectral and spatial resolution combined with high luminosity discovered new types of X-ray spectra. These new types are characterised by the disappearance of the resonance lines and the strong emission of dielectronic satellite spectra. Several types of transitions of highly charged ions are discovered which are unknown from usual sources employed in atomic physics. New theoretical models are developed and successfully applied for the interpretation and for plasma diagnostics. (orig.) 28 refs.

  16. Extracting chemical information from high-resolutionX-ray emission spectroscopy

    Science.gov (United States)

    Limandri, S.; Robledo, J.; Tirao, G.

    2018-06-01

    High-resolution X-ray emission spectroscopy allows studying the chemical environment of a wide variety of materials. Chemical information can be obtained by fitting the X-ray spectra and observing the behavior of some spectral features. Spectral changes can also be quantified by means of statistical parameters calculated by considering the spectrum as a probability distribution. Another possibility is to perform statistical multivariate analysis, such as principal component analysis. In this work the performance of these procedures for extracting chemical information in X-ray emission spectroscopy spectra for mixtures of Mn2+ and Mn4+ oxides are studied. A detail analysis of the parameters obtained, as well as the associated uncertainties is shown. The methodologies are also applied for Mn oxidation state characterization of double perovskite oxides Ba1+xLa1-xMnSbO6 (with 0 ≤ x ≤ 0.7). The results show that statistical parameters and multivariate analysis are the most suitable for the analysis of this kind of spectra.

  17. Coronal temperature diagnostics from high-resolution soft X-ray spectra

    Science.gov (United States)

    Strong, K. T.; Claflin, E. S.; Lemen, J. R.; Linford, G. A.

    1988-01-01

    The problem of deriving the temperature of the coronal plasma from soft X-ray spectra is discussed. Spectral atlas scans of the soft X-ray spectrum from the Flat Crystal Spectrometer on the Solar Maximum Mission are compared with theoretical predictions of the relative intensities of some of the brighter lines to determine which line intensity ratios give the most reliable temperature diagnostics. The techniques considered include line widths, He-like G ratios, intensity ratios, and ratios of lines formed by different elements. It is found that the best temperature diagnostics come from the ratios of lines formed by successive ionization stages of the same element.

  18. 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.

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

    International Nuclear Information System (INIS)

    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

  20. 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.

  1. A high resolution x-ray fluorescence spectrometer for near edge absorption studies

    International Nuclear Information System (INIS)

    Stojanoff, V.; Hamalainen, K.; Siddons, D.P.; Hastings, J.B.; Berman, L.E.; Cramer, S.; Smith, G.

    1991-01-01

    A high resolution fluorescence spectrometer using a Johann geometry in a back scattering arrangement was developed. The spectrometer, with a resolution of 0.3 eV at 6.5 keV, combined with an incident beam, with a resolution of 0.7 eV, form the basis of a high resolution instrument for measuring x-ray absorption spectra. The advantages of the instrument are illustrated with the near edge absorption spectrum of dysprosium nitrate. 10 refs., 4 figs

  2. Modeling X-ray Spectra of Astrophysical Plasmas: Current Status and Future Needs

    Science.gov (United States)

    Smith, Randall

    Existing high-resolution astrophysical X-ray spectra has exposed the need for high-quality atomic data of all stripes: wavelengths, collisional and absorption cross sections, and radiative rates. The Astro-H soft X-ray spectrometer (2015 launch) will vastly increase the number and type of high-resolution X-ray spectra available and likely expose a number of shortcomings in our models. I will describe recent advances in theoretical calculations and laboratory measurements, as well as a number of existing needs in the field. These include accurate soft X-ray wavelengths for L-shell ions, diagnostic emission line ratios with estimated error bars, and high-resolution absorption cross sections for abundant ions and molecules. Finally, new models of emission from non-equilibrium ionization plasmas and astrophysical charge exchange will be discussed. This latter emission arises due to the interaction of highly charged ions with neutral atoms, forming a diffuse background in the case of solar wind ions and possibly also arising in more distant environments.

  3. 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...

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

    International Nuclear Information System (INIS)

    Wang, Xin

    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 Kα and Kβ 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

  5. Development of Compton X-ray spectrometer for high energy resolution single-shot high-flux hard X-ray spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Kojima, Sadaoki, E-mail: kojima-s@ile.osaka-u.ac.jp, E-mail: sfujioka@ile.osaka-u.ac.jp; Ikenouchi, Takahito; Arikawa, Yasunobu; Sakata, Shohei; Zhang, Zhe; Abe, Yuki; Nakai, Mitsuo; Nishimura, Hiroaki; Shiraga, Hiroyuki; Fujioka, Shinsuke, E-mail: kojima-s@ile.osaka-u.ac.jp, E-mail: sfujioka@ile.osaka-u.ac.jp; Azechi, Hiroshi [Institute of Laser Engineering, Osaka University, 2-6 Yamada-oka, Suita, Osaka 565-0871 (Japan); Ozaki, Tetsuo [National Institute for Fusion Science, 322-6 Oroshi, Toki, Gifu 509-5292 (Japan); Miyamoto, Shuji; Yamaguchi, Masashi; Takemoto, Akinori [Laboratory of Advanced Science and Technology for Industry, University of Hyogo, 3-1-2 Kouto, Kamigori-cho, Ako-gun, Hyogo 678-1205 (Japan)

    2016-04-15

    Hard X-ray spectroscopy is an essential diagnostics used to understand physical processes that take place in high energy density plasmas produced by intense laser-plasma interactions. A bundle of hard X-ray detectors, of which the responses have different energy thresholds, is used as a conventional single-shot spectrometer for high-flux (>10{sup 13} photons/shot) hard X-rays. However, high energy resolution (Δhv/hv < 0.1) is not achievable with a differential energy threshold (DET) X-ray spectrometer because its energy resolution is limited by energy differences between the response thresholds. Experimental demonstration of a Compton X-ray spectrometer has already been performed for obtaining higher energy resolution than that of DET spectrometers. In this paper, we describe design details of the Compton X-ray spectrometer, especially dependence of energy resolution and absolute response on photon-electron converter design and its background reduction scheme, and also its application to the laser-plasma interaction experiment. The developed spectrometer was used for spectroscopy of bremsstrahlung X-rays generated by intense laser-plasma interactions using a 200 μm thickness SiO{sub 2} converter. The X-ray spectrum obtained with the Compton X-ray spectrometer is consistent with that obtained with a DET X-ray spectrometer, furthermore higher certainly of a spectral intensity is obtained with the Compton X-ray spectrometer than that with the DET X-ray spectrometer in the photon energy range above 5 MeV.

  6. Soft x-ray absorption spectra of ilmenite family.

    Science.gov (United States)

    Agui, A; Mizumaki, M; Saitoh, Y; Matsushita, T; Nakatani, T; Fukaya, A; Torikai, E

    2001-03-01

    We have carried out soft x-ray absorption spectroscopy to study the electronic structure of ilmenite family, such as MnTiO3, FeTiO3, and CoTiO3 at the soft x-ray beamline, BL23SU, at the SPring-8. The Ti and M L2,3 absorption spectra of MTiO3 (M=Mn, Fe, and Co) show spectra of Ti4+ and M2+ electron configurations, respectively. Except the Fe L2,3 spectrum, those spectra were understood within the O(h) symmetry around the transition metal ions. The Fe L3-edge spectrum clearly shows a doublet peak at the L3 edge, which is attributed to Fe2+ state, moreover the very high-resolution the L-edge spectra of transition metals show fine structures. The spectra of those ilmenites are compared.

  7. High resolution X-ray spectromicroscopy of laser produced plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Faenov, A.Ya. [Multi-charged Ions Spectra Data Center of VNIIFTRI (MISDC), Mendeleevo, Moscow region, (Russian Federation)

    2000-01-01

    In recent years new classes of X-ray spectroscopic instruments possessing both dispersive and focusing properties have been manufactured. Their principal advantage over more traditional instruments is that they combine very high luminosity with high spatial resolution, while preserving the highest possible spectral resolution of their dispersive elements. These instruments opened up the registration of plasmas in new regimes and surroundings. The measurements delivered new information about the properties of even previously studied traditional plasma objects (e.g. ns-laser produced plasmas). Also the detailed investigation of relatively new plasma laboratory sources with very small dimensions and low energy content (e.g. mJ fs-laser pulses) became possible. The purpose of this report is to give a short review of the experimental and theoretical results obtained in the past few years by MISDC (Multi-charged Ions Spectra Data Center) research team in the field of X-ray spectroscopy of a laser-produced plasma. Experimental spectra have been obtained at various laser installations with nanosecond, sub-nanosecond, picosecond and sub-picosecond pulses interacting with solid, gaseous or cluster targets in collaborations with research teams from Russia, USA, Germany, France, Poland, Belgium, Italy, China and Israel. Practically all results have been obtained with the help of spectrographs with spherically bent mica crystals operating in FSSR-1D, 2D schemes. (author)

  8. High Resolution Energetic X-ray Imager (HREXI)

    Science.gov (United States)

    Grindlay, Jonathan

    We propose to design and build the first imaging hard X-ray detector system that incorporates 3D stacking of closely packed detector readouts in finely-spaced imaging arrays with their required data processing and control electronics. In virtually all imaging astronomical detectors, detector readout is done with flex connectors or connections that are not vertical but rather horizontal , requiring loss of focal plane area. For high resolution pixel detectors needed for high speed event-based X-ray imaging, from low energy applications (CMOS) with focusing X-ray telescopes, to hard X-ray applications with pixelated CZT for large area coded aperture telescopes, this new detector development offers great promise. We propose to extend our previous and current APRA supported ProtoEXIST program that has developed the first large area imaging CZT detectors and demonstrated their astrophysical capabilities on two successful balloon flight to a next generation High Resolution Energetic X-ray Imager (HREXI), which would incorporate microvia technology for the first time to connect the readout ASIC on each CZT crystal directly to its control and data processing system. This 3-dimensional stacking of detector and readout/control system means that large area (>2m2) imaging detector planes for a High Resolution Wide-field hard X-ray telescope can be built with initially greatly reduced detector gaps and ultimately with no gaps. This increases detector area, efficiency, and simplicity of detector integration. Thus higher sensitivity wide-field imagers will be possible at lower cost. HREXI will enable a post-Swift NASA mission such as the EREXS concept proposed to PCOS to be conducted as a future MIDEX mission. This mission would conduct a high resolution (<2 arcmin) , broad band (5 200 keV) hard X-ray survey of black holes on all scales with ~10X higher sensitivity than Swift. In the current era of Time Domain Astrophysics, such a survey capability, in conjunction with a n

  9. Tetrahedral hydrocarbon nanoparticles in space: X-ray spectra

    Science.gov (United States)

    Bilalbegović, G.; Maksimović, A.; Valencic, L. A.

    2018-06-01

    It has been proposed, or confirmed, that diamond nanoparticles exist in various environments in space: close to active galactic nuclei, in the vicinity of supernovae and pulsars, in the interior of several planets in the Solar system, in carbon planets, and other exoplanets, carbon-rich stars, meteorites, in X-ray active Herbig Ae/Be stars, and in the interstellar medium. Using density functional theory methods, we calculate the carbon K-edge X-ray absorption spectrum of two large tetrahedral nanodiamonds: C26H32 and C51H52. We also study and test our methods on the astrophysical molecule CH4, the smallest C-H tetrahedral structure. A possible detection of nanodiamonds from X-ray spectra by future telescopes, such as the project Arcus, is proposed. Simulated spectra of the diffuse interstellar medium using Cyg X-2 as a source show that nanodiamonds studied in this work can be detected by Arcus, a high-resolution X-ray spectrometer mission selected by NASA for a Phase A concept study.

  10. Active x-ray optics for high resolution space telescopes

    Science.gov (United States)

    Doel, Peter; Atkins, Carolyn; Brooks, D.; Feldman, Charlotte; Willingale, Richard; Button, Tim; Rodriguez Sanmartin, Daniel; Meggs, Carl; James, Ady; Willis, Graham; Smith, Andy

    2017-11-01

    The Smart X-ray Optics (SXO) Basic Technology project started in April 2006 and will end in October 2010. The aim is to develop new technologies in the field of X-ray focusing, in particular the application of active and adaptive optics. While very major advances have been made in active/adaptive astronomical optics for visible light, little was previously achieved for X-ray optics where the technological challenges differ because of the much shorter wavelengths involved. The field of X-ray astronomy has been characterized by the development and launch of ever larger observatories with the culmination in the European Space Agency's XMM-Newton and NASA's Chandra missions which are currently operational. XMM-Newton uses a multi-nested structure to provide modest angular resolution ( 10 arcsec) but large effective area, while Chandra sacrifices effective area to achieve the optical stability necessary to provide sub-arc second resolution. Currently the European Space Agency (ESA) is engaged in studies of the next generation of X-ray space observatories, with the aim of producing telescopes with increased sensitivity and resolution. To achieve these aims several telescopes have been proposed, for example ESA and NASA's combined International X-ray Observatory (IXO), aimed at spectroscopy, and NASA's Generation-X. In the field of X-ray astronomy sub 0.2 arcsecond resolution with high efficiency would be very exciting. Such resolution is unlikely to be achieved by anything other than an active system. The benefits of a such a high resolution would be important for a range of astrophysics subjects, for example the potential angular resolution offered by active X-ray optics could provide unprecedented structural imaging detail of the Solar Wind bowshock interaction of comets, planets and similar objects and auroral phenomena throughout the Solar system using an observing platform in low Earth orbit. A major aim of the SXO project was to investigate the production of thin

  11. Ultraprecision motion control technique for high-resolution x-ray instrumentation

    Energy Technology Data Exchange (ETDEWEB)

    Shu, D.; Toellner, T. S.; Alp, E. E.

    2000-07-17

    With the availability of third-generation hard x-ray synchrotron radiation sources, such as the Advanced Photon Source (APS) at Argonne National Laboratory, x-ray inelastic scattering and x-ray nuclear resonant scattering provide powerful means for investigating the vibrational dynamics of a variety of materials and condensed matter systems. Novel high-resolution hard x-ray optics with meV energy resolution requires a compact positioning mechanism with 20--50-nrad angular resolution and stability. In this paper, the authors technical approach to this design challenge is presented. Sensitivity and stability test results are also discussed.

  12. High-resolution nonresonant x-ray Raman scattering study on rare earth phosphate nanoparticles

    NARCIS (Netherlands)

    Huotari, Simo; Suljoti, Edlira; Sahle, Christoph J.; Raedel, Stephanie; Monaco, Giulio; de Groot, Frank M. F.

    2015-01-01

    We report high-resolution x-ray Raman scattering studies of high-order multipole spectra of rare earth 4d -> 4f excitations (the N-4,N-5 absorption edge) in nanoparticles of the phosphates LaPO4, CePO4, PrPO4, and NdPO4. We also present corresponding data for La 5p -> 5d excitations (the O-2,O-3

  13. 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.

  14. 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.

  15. 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.

  16. Time-resolved x-ray spectra of laser irradiated high-Z targets

    International Nuclear Information System (INIS)

    Lee, P.H.Y.; Attwood, D.T.; Boyle, M.J.; Campbell, E.M.; Coleman, L.C.; Kornblum, H.N.

    1977-01-01

    Recent results obtained by using the Livermore 15 psec x-ray streak camera to record x-ray emission from laser-irradiated high-z targets in the 1-20 keV range are reported. Nine to eleven K-edge filter channels were used for the measurements. In the lower energy channels, a dynamic range of x-ray emission intensity of better than three orders of magnitude have been recorded. Data will be presented which describe temporally and spectrally resolved x-ray spectra of gold disk targets irradiated by laser pulses from the Argus facility, including the temporal evolution of the superthermal x-ray tail

  17. A high resolution position sensitive X-ray MWPC for small angle X-ray diffraction

    International Nuclear Information System (INIS)

    Bateman, J.E.; Connolly, J.F.; Stephenson, R.; Tappern, G.J.

    1981-02-01

    A small sealed-off delay line readout MWPC X-ray detector has been designed and built for small angle X-ray diffraction applications. Featuring a sensitive area of 100 mm x 25 mm it yields a spatial resolution of 0.13 mm (standard deviation) with a high rate capability and good quantum efficiency for copper K radiation. (author)

  18. Development of high resolution x-ray CT technique for irradiated fuel assembly

    Energy Technology Data Exchange (ETDEWEB)

    Ishimi, Akihiro; Katsuyama, Kozo; Maeda, Koji; Asaga, Takeo [Japan Atomic Energy Agency, Oarai Research and Development Center, Oarai, Ibaraki (Japan)

    2012-03-15

    High X-ray CT technique was developed to observe the irradiation performance of FBR fuel assembly and MOX fuel. In this technique, the high energy X-ray pulse (12MeV) was used synchronizing detection system with the X-ray pulse to reduce the effect of the gamma ray emissions from the irradiated fuel assembly. In this study, this technique was upgraded to obtain high resolution X-ray CT image. In this upgrading, the collimator which had slit width of 0.1 mm and X-ray detector of a highly sensitive silicon semiconductor detector (100 channels) was introduced in the X-ray CT system. As a result of these developments, high resolution X-ray CT images could be obtained on the transverse cross section of irradiated fuel assembly. (author)

  19. High-resolution X-ray spectra from low-temperature, highly charged ions

    International Nuclear Information System (INIS)

    Beiersdorfer, P.

    1996-09-01

    The electron beam ion traps (EBIT) at Livermore were designed for studying the x-ray emission of highly charged ions produced and excited by a monoenergetic electron beam. The precision with which the x-ray emission can be analyzed has recently been increased markedly when it became possible to decouple the temperature of the ions from the energy of the electron beam by several orders of magnitude. By adjusting the trap parameters, ion temperatures as low as 15.8±4.4 eV for Ti 20+ and 59.4±9.9 eV for Cs 45+ were achieved. These temperatures were more than two orders of magnitude lower than the energy of the multi-keV electron beam used for the production and excitation of the ions. A discussion of the techniques used to produce and study low-temperature highly charged ions is presented in this progress report. The low ion temperatures enabled measurements heretofore impossible. As an example, a direct observation of the natural line width of fast electric dipole allowed x-ray transitions is described. From the observed natural line width and b making use of the time-energy relations of the uncertainty principle we were able to determine a radiative transition rate of 1.65 fs for the 2p-3d resonance transition in neonlike Cs 45+ . A brief discussion of other high-precision measurements enabled by our new technique is also given

  20. 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.

  1. High-spatial resolution and high-spectral resolution detector for use in the measurement of solar flare hard x rays

    International Nuclear Information System (INIS)

    Desai, U.D.; Orwig, L.E.

    1988-01-01

    In the areas of high spatial resolution, the evaluation of a hard X-ray detector with 65 micron spatial resolution for operation in the energy range from 30 to 400 keV is proposed. The basic detector is a thick large-area scintillator faceplate, composed of a matrix of high-density scintillating glass fibers, attached to a proximity type image intensifier tube with a resistive-anode digital readout system. Such a detector, combined with a coded-aperture mask, would be ideal for use as a modest-sized hard X-ray imaging instrument up to X-ray energies as high as several hundred keV. As an integral part of this study it was also proposed that several techniques be critically evaluated for X-ray image coding which could be used with this detector. In the area of high spectral resolution, it is proposed to evaluate two different types of detectors for use as X-ray spectrometers for solar flares: planar silicon detectors and high-purity germanium detectors (HPGe). Instruments utilizing these high-spatial-resolution detectors for hard X-ray imaging measurements from 30 to 400 keV and high-spectral-resolution detectors for measurements over a similar energy range would be ideally suited for making crucial solar flare observations during the upcoming maximum in the solar cycle

  2. Stress Free Multilayer Coating for High Resolution X-ray Mirrors

    Data.gov (United States)

    National Aeronautics and Space Administration — Most of X-ray optics research and development in the US is to build a high resolution, large collecting area and light-weight optic, namely an soft X-ray mirror for...

  3. Ultra high resolution soft x-ray tomography

    International Nuclear Information System (INIS)

    Haddad, W.S.; Trebes, J.E.; Goodman, D.M.

    1995-01-01

    Ultra high resolution three dimensional images of a microscopic test object were made with soft x-rays using a scanning transmission x-ray microscope. The test object consisted of two different patterns of gold bars on silicon nitride windows that were separated by ∼5μm. A series of nine 2-D images of the object were recorded at angles between -50 to +55 degrees with respect to the beam axis. The projections were then combined tomographically to form a 3-D image by means of an algebraic reconstruction technique (ART) algorithm. A transverse resolution of ∼1000 Angstrom was observed. Artifacts in the reconstruction limited the overall depth resolution to ∼6000 Angstrom, however some features were clearly reconstructed with a depth resolution of ∼1000 Angstrom. A specially modified ART algorithm and a constrained conjugate gradient (CCG) code were also developed as improvements over the standard ART algorithm. Both of these methods made significant improvements in the overall depth resolution bringing it down to ∼1200 Angstrom overall. Preliminary projection data sets were also recorded with both dry and re-hydrated human sperm cells over a similar angular range

  4. Ultra high resolution soft x-ray tomography

    International Nuclear Information System (INIS)

    Haddad, W.S.; Trebes, J.E.; Goodman, D.M.; Lee, H.R.; McNulty, I.; Zalensky, A.O.

    1995-01-01

    Ultra high resolution three dimensional images of a microscopic test object were made with soft x-rays using a scanning transmission x-ray microscope. The test object consisted of two different patterns of gold bars on silicon nitride windows that were separated by ∼5 microm. A series of nine 2-D images of the object were recorded at angles between -50 to +55 degrees with respect to the beam axis. The projections were then combined tomographically to form a 3-D image by means of an algebraic reconstruction technique (ART) algorithm. A transverse resolution of ∼ 1,000 angstrom was observed. Artifacts in the reconstruction limited the overall depth resolution to ∼ 6,000 angstrom, however some features were clearly reconstructed with a depth resolution of ∼ 1,000 angstrom. A specially modified ART algorithm and a constrained conjugate gradient (CCG) code were also developed as improvements over the standard ART algorithm. Both of these methods made significant improvements in the overall depth resolution, bringing it down to ∼ 1,200 angstrom overall. Preliminary projection data sets were also recorded with both dry and re-hydrated human sperm cells over a similar angular range

  5. 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.

  6. High-resolution K-shell spectra from laser excited molybdenum plasmas

    Directory of Open Access Journals (Sweden)

    Szabo C.I.

    2013-11-01

    Full Text Available X-ray spectra from Molybdenum plasmas were recorded by a Cauchois-type cylindrically bent Transmission Crystal Spectrometer (TCS. The absolutely calibrated spectrometer provides an unprecedented resolution of inner shell transitions (K x-ray radiation. This tool allows us to resolve individual lines from different charge states existing inside the laser-produced plasma. The inner shell transitions from highly charged Molybdenum shown in this report have never been resolved before in such detail in a laser-produced plasma.

  7. High-Quality Medium-Resolution Gamma-Ray Spectra from Certified Reference Uranium and Plutonium Materials

    International Nuclear Information System (INIS)

    Zsigrai, J.; Muehleisen, A.; ); Weber, A.-L.; Funk, P.; Berlizov, A.; Mintcheva, J.

    2015-01-01

    The Institute of Transuranium Elements (ITU) has made an effort to record a collection of medium resolution gamma-ray spectra from well-characterized U and Pu certified reference materials CRM-171 (also known as SRM-969), CBNM-271, and Harwell PIDIE standards. The goal of this exercise was twofold: (i) to complement the international database of reference gamma-ray spectra with high-quality data for medium resolution spectrometers, and (ii) to feed Phase I of the U/Pu isotopic inter-comparison exercise that is being jointly organized by the ESARDA NDA Working Group and IAEA. Phase II of the exercise will be fed by similar spectra recorded by Institute for Radiological Protection and Nuclear Safety (IRSN). These activities are supported through a joint Member State Support Programmes (MSSP) task and aimed at delivering reliable methodologies for the determination of U/Pu isotopic composition using medium resolution gamma-spectrometers. The latter have obvious benefits for in-field applications, amongst which are better usability, portability and maintainability. As the spectra will be made available online for software developers and end users, ultimately this will also contribute to sustainability as well as the improved and validated performance of existing U/Pu isotopic codes. The spectra were recorded using the IAEA's standard Lanthanum Bromide (LaBr3(Ce)) (2.0'' x 0.5'') and Cadmium Zink Telluride (CdZnTe) (500 mm''3) detectors and acquisition electronics. Aiming to acquire the highest quality reference data, the spectra were measured for long acquisition times, ensuring very good counting statistics across potentially useful spectral intervals — up to 1 MeV for the CdZnTe and up to 2.6 MeV for the LaBr3(Ce) detectors. Great attention was also paid to ensure that the measurement geometry was stable and reproducible, and the spectra had minimum influence from background radiation and pile-up effects. The paper will briefly

  8. High spectral resolution X-ray observations of AGN

    NARCIS (Netherlands)

    Kaastra, J.S.

    2008-01-01

    brief overview of some highlights of high spectral resolution X-ray observations of AGN is given, mainly obtained with the RGS of XMM-Newton. Future prospects for such observations with XMM-Newton are given.

  9. A high-resolution multiwire area detector for X-ray scattering

    Energy Technology Data Exchange (ETDEWEB)

    Faruqi, A R; Andrews, H [Medical Research Council, Cambridge (UK). Lab. of Molecular Biology

    1989-11-10

    A high-resolution multiwire area detector has been developed for recording X-ray scattering from biological specimens. The detector is 100x100 mm{sup 2} and, under the present operating conditions, has a spatial resolution of about 250 {mu}m in both directions. The detector is set up on a double-mirror focusing camera on a rotating anode X-ray generator and has been used in a number of small-angle experiments, two of which are described in this paper. (orig.).

  10. High-Resolution Detector For X-Ray Diffraction

    Science.gov (United States)

    Carter, Daniel C.; Withrow, William K.; Pusey, Marc L.; Yost, Vaughn H.

    1988-01-01

    Proposed x-ray-sensitive imaging detector offers superior spatial resolution, counting-rate capacity, and dynamic range. Instrument based on laser-stimulated luminescence and reusable x-ray-sensitive film. Detector scans x-ray film line by line. Extracts latent image in film and simultaneously erases film for reuse. Used primarily for protein crystallography. Principle adapted to imaging detectors for electron microscopy and fluorescence spectroscopy and general use in astronomy, engineering, and medicine.

  11. Digital signal processors for cryogenic high-resolution x-ray detector readout

    International Nuclear Information System (INIS)

    Friedrich, Stephan; Drury, Owen B.; Bechstein, Sylke; Hennig, Wolfgang; Momayezi, Michael

    2003-01-01

    We are developing fast digital signal processors (DSPs) to read out superconducting high-resolution X-ray detectors with on-line pulse processing. For superconducting tunnel junction (STJ) detector read-out, the DSPs offer online filtering, rise time discrimination and pile-up rejection. Compared to analog pulse processing, DSP readout somewhat degrades the detector resolution, but improves the spectral purity of the detector response. We discuss DSP performance with our 9-channel STJ array for synchrotron-based high-resolution X-ray spectroscopy. (author)

  12. 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 ...

  13. A Chandra High-Resolution X-ray Image of Centaurus A.

    Science.gov (United States)

    Kraft; Forman; Jones; Kenter; Murray; Aldcroft; Elvis; Evans; Fabbiano; Isobe; Jerius; Karovska; Kim; Prestwich; Primini; Schwartz; Schreier; Vikhlinin

    2000-03-01

    We present first results from a Chandra X-Ray Observatory observation of the radio galaxy Centaurus A with the High-Resolution Camera. All previously reported major sources of X-ray emission including the bright nucleus, the jet, individual point sources, and diffuse emission are resolved or detected. The spatial resolution of this observation is better than 1&arcsec; in the center of the field of view and allows us to resolve X-ray features of this galaxy not previously seen. In particular, we resolve individual knots of emission in the inner jet and diffuse emission between the knots. All of the knots are diffuse at the 1&arcsec; level, and several exhibit complex spatial structure. We find the nucleus to be extended by a few tenths of an arcsecond. Our image also suggests the presence of an X-ray counterjet. Weak X-ray emission from the southwest radio lobe is also seen, and we detect 63 pointlike galactic sources (probably X-ray binaries and supernova remnants) above a luminosity limit of approximately 1.7x1037 ergs s-1.

  14. High-resolution X-ray crystal structure of bovine H-protein using the high-pressure cryocooling method

    International Nuclear Information System (INIS)

    Higashiura, Akifumi; Ohta, Kazunori; Masaki, Mika; Sato, Masaru; Inaka, Koji; Tanaka, Hiroaki; Nakagawa, Atsushi

    2013-01-01

    Using the high-pressure cryocooling method, the high-resolution X-ray crystal structure of bovine H-protein was determined at 0.86 Å resolution. This is the first ultra-high-resolution structure obtained from a high-pressure cryocooled crystal. Recently, many technical improvements in macromolecular X-ray crystallography have increased the number of structures deposited in the Protein Data Bank and improved the resolution limit of protein structures. Almost all high-resolution structures have been determined using a synchrotron radiation source in conjunction with cryocooling techniques, which are required in order to minimize radiation damage. However, optimization of cryoprotectant conditions is a time-consuming and difficult step. To overcome this problem, the high-pressure cryocooling method was developed (Kim et al., 2005 ▶) and successfully applied to many protein-structure analyses. In this report, using the high-pressure cryocooling method, the X-ray crystal structure of bovine H-protein was determined at 0.86 Å resolution. Structural comparisons between high- and ambient-pressure cryocooled crystals at ultra-high resolution illustrate the versatility of this technique. This is the first ultra-high-resolution X-ray structure obtained using the high-pressure cryocooling method

  15. A laboratory-based hard x-ray monochromator for high-resolution x-ray emission spectroscopy and x-ray absorption near edge structure measurements

    Energy Technology Data Exchange (ETDEWEB)

    Seidler, G. T., E-mail: seidler@uw.edu; Mortensen, D. R.; Remesnik, A. J.; Pacold, J. I.; Ball, N. A.; Barry, N.; Styczinski, M.; Hoidn, O. R. [Physics Department, University of Washington, Seattle, Washington 98195-1560 (United States)

    2014-11-15

    We report the development of a laboratory-based Rowland-circle monochromator that incorporates a low power x-ray (bremsstrahlung) tube source, a spherically bent crystal analyzer, and an energy-resolving solid-state detector. This relatively inexpensive, introductory level instrument achieves 1-eV energy resolution for photon energies of ∼5 keV to ∼10 keV while also demonstrating a net efficiency previously seen only in laboratory monochromators having much coarser energy resolution. Despite the use of only a compact, air-cooled 10 W x-ray tube, we find count rates for nonresonant x-ray emission spectroscopy comparable to those achieved at monochromatized spectroscopy beamlines at synchrotron light sources. For x-ray absorption near edge structure, the monochromatized flux is small (due to the use of a low-powered x-ray generator) but still useful for routine transmission-mode studies of concentrated samples. These results indicate that upgrading to a standard commercial high-power line-focused x-ray tube or rotating anode x-ray generator would result in monochromatized fluxes of order 10{sup 6}–10{sup 7} photons/s with no loss in energy resolution. This work establishes core technical capabilities for a rejuvenation of laboratory-based hard x-ray spectroscopies that could have special relevance for contemporary research on catalytic or electrical energy storage systems using transition-metal, lanthanide, or noble-metal active species.

  16. 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.

  17. Diamond x-ray optics: Transparent, resilient, high-resolution, and wavefront preserving

    International Nuclear Information System (INIS)

    Shvyd’ko, Yuri; Blank, Vladimir; Terentyev, Sergey

    2017-01-01

    Diamond features a unique combination of outstanding physical properties perfect for numerous x-ray optics applications, where traditional materials such as silicon fail to perform. In the last two decades, impressive progress has been achieved in synthesizing diamond with high crystalline perfection, in manufacturing efficient, resilient, high-resolution, wavefront-preserving diamond optical components, and in implementing them in cutting-edge x-ray instruments. Diamond optics are essential for tailoring x-rays to the most challenging needs of x-ray research. Furthermore, they are becoming vital for the generation of fully coherent hard x-rays by seeded x-ray free-electron lasers. In this article, we review progress in manufacturing flawless diamond crystal components and their applications in diverse x-ray optical devices, such as x-ray monochromators, beam splitters, high-reflectance backscattering mirrors, lenses, phase plates, diffraction gratings, bent-crystal spectrographs, and windows.

  18. 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.

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

    NARCIS (Netherlands)

    de Groot, F.M.F.

    2016-01-01

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

  20. High-resolution inelastic X-ray scattering to study the high-frequency atomic dynamics of disordered systems

    International Nuclear Information System (INIS)

    Monaco, G.

    2008-01-01

    The use of momentum-resolved inelastic X-ray scattering with meV energy resolution to study the high-frequency atomic dynamics in disordered systems is here reviewed. The typical realization of this experiment is described together with some common models used to interpret the measured spectra and to extract parameters of interest for the investigation of disordered systems. With the help of some selected examples, the present status of the field is discussed. Particular attention is given to those results which are still open for discussion or controversial, and which will require further development of the technique to be fully solved. Such an instrumental development seems nowadays possible at the light of recently proposed schemes for advanced inelastic X-ray scattering spectrometers. (author)

  1. 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).

  2. X ray spectra of X Per. [oso-8 observations

    Science.gov (United States)

    Becker, R. H.; Boldt, E. A.; Holt, S. S.; Pravdo, S. H.; Robinson-Saba, J.; Serlemitsos, P. J.; Swank, J. H.

    1978-01-01

    The cosmic X-ray spectroscopy experiment on OSO-8 observed X Per for twenty days during two observations in Feb. 1976 and Feb. 1977. The spectrum of X Per varies in phase with its 13.9 min period, hardening significantly at X-ray minimum. Unlike other X-ray binary pulsar spectra, X Per's spectra do not exhibit iron line emission or strong absorption features. The data show no evidence for a 22 hour periodicity in the X-ray intensity of X Per. These results indicate that the X-ray emission from X Per may be originating from a neutron star in a low density region far from the optically identified Be star.

  3. 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.

  4. High resolution X-ray emission spectroscopy: An advanced tool for actinide research

    Science.gov (United States)

    Vitova, T.; Brendebach, B.; Dardenne, K.; Denecke, M. A.; Lebid, A.; Löble, M.; Rothe, J.; Batuk, O. N.; Hormes, J.; Liu, D.; Breher, F.; Geckeis, H.

    2010-03-01

    High resolution X-ray emission spectroscopy (HRXES) is becoming increasingly important for our understanding of electronic and coordination structures. The combination of such information with development of quantum theoretical tools will advance our capability for predicting reactivity and physical behavior especially of 5f elements. HRXES can be used to remove lifetime broadening by registering the partial fluorescence yield emitted by the sample (i.e., recording a windowed signal from the energy dispersed fluorescence emission while varying incident photon energy), thereby yielding highly resolved X-ray absorption fine structure (XAFS) spectra. Such spectra often display resonant features not observed in conventional XAFS. The spectrometer set-up can also be used for a wide range of other experiments, for example, resonant inelastic X-ray scattering (RIXS), where bulk electron configuration information in solids, liquids and gases is obtained. Valence-selective XAFS studies, where the local structure of a selected element's valence state present in a mixture of valence states can be obtained, as well as site-selective XAFS studies, where the coordination structure of a metal bound to selected elements can be differentiated from that of all the other ligating atoms. A HRXES spectrometer has been constructed and is presently being commissioned for use at the INE-Beamline for actinide research at the synchrotron source ANKA at FZK. We present the spectrometer's compact, modular design, optimized for attaining a wide range of energies, and first test measurement results. Examples from HRXES studies of lanthanides, actinides counter parts, are also shown.

  5. The development of high resolution silicon x-ray microcalorimeters

    Science.gov (United States)

    Porter, F. S.; Kelley, R. L.; Kilbourne, C. A.

    2005-12-01

    Recently we have produced x-ray microcalorimeters with resolving powers approaching 2000 at 5.9 keV using a spare XRS microcalorimeter array. We attached 400 um square, 8 um thick HgTe absorbers using a variety of attachment methods to an XRS array and ran the detector array at temperatures between 40 and 60 mK. The best results were for absorbers attached using the standard XRS absorber-pixel thermal isolation scheme utilizing SU8 polymer tubes. In this scenario we achieved a resolution of 3.2 eV FWHM at 5.9 keV. Substituting a silicon spacer for the SU8 tubes also yielded sub-4eV results. In contrast, absorbers attached directly to the thermistor produced significant position dependence and thus degraded resolution. Finally, we tested standard 640um-square XRS detectors at reduced bias power at 50mK and achieved a resolution of 3.7eV, a 50% improvement over the XRS flight instrument. Implanted silicon microcalorimeters are a mature flight-qualified technology that still has a substantial phase space for future development. We will discuss these new high resolution results, the various absorber attachment schemes, planned future improvements, and, finally, their relevance to future high resolution x-ray spectrometers including Constellation-X.

  6. Theoretically predicted soft x-ray emission and absorption spectra of graphitic-structured BC2N

    Science.gov (United States)

    Muramatsu, Yasuji

    Theoretical B K, C K and N K x-ray emission/absorption spectra of three possible graphitic-structured BC2N clusters are predicted based on the B2p-, C2p-, and N2p- density-of-states (DOS) calculated by discrete variational (DV)-X[alpha] molecular orbital calculations. Several prominent differences in DOS spectral features among BC2Ns, h-BN, and graphite are confirmed from comparison of calculated B2p-, C2p-, and N2p-DOS spectra. These variations in the spectra allow BC2N structures to be positively identified by high-resolution x-ray emission/absorption spectroscopy in the B K, C K, and N K regions.

  7. High resolution measurements of Cyg X-1 from rockets

    International Nuclear Information System (INIS)

    Rothschild, R.E.; Boldt, E.A.; Holt, S.S.; Serlemitsos, P.J.

    1976-01-01

    Cyg X-1 was observed on two occasions (Oct. 4, 1973 and Oct. 3, 1974) by the Goddard x-ray rocket payload. This payload consisted of two gas proportional counters (xenon--methane with 710 cm 2 and argon--methane with 610 cm 2 ) using the same 128 channel pulse height analyzer and having 320 μs temporal resolution on the 1973 flight and 160 μs resolution on the 1974 flight. During both flights bursts of 1 ms duration were observed with very high statistical certainty. To date all 13 of these bursts have been analyzed for spectral and temporal character, and the results of this analysis are presented. The spectra of overall x-ray emission from both flights are also presented. In a source known for its variability it is remarkable that the spectra taken one year apart are virtually identical

  8. SMART-X: Square Meter, Arcsecond Resolution Telescope for X-rays

    Science.gov (United States)

    Vikhlinin, Alexey; SMART-X Collaboration

    2013-04-01

    SMART-X is a concept for a next-generation X-ray observatory with large-area, 0.5" angular resolution grazing incidence adjustable X-ray mirrors, high-throughput critical angle transmission gratings, and X-ray microcalorimeter and CMOS-based imager in the focal plane. High angular resolution is enabled by new technology based on controlling the shape of mirror segments using thin film piezo actuators deposited on the back surface. Science applications include observations of growth of supermassive black holes since redshifts of ~10, ultra-deep surveys over 10's of square degrees, galaxy assembly at z=2-3, as well as new opportunities in the high-resolution X-ray spectroscopy and time domains. We also review the progress in technology development, tests, and mission design over the past year.

  9. High resolution projection X-ray microscope equipped with fluorescent X-ray analyzer and its applications

    International Nuclear Information System (INIS)

    Minami, K; Saito, Y; Kai, H; Shirota, K; Yada, K

    2009-01-01

    We have newly developed an open type fine-focus X-ray tube 'TX-510' to realize a spatial resolution of 50nm and to radiate low energy characteristic X-rays for giving high absorption contrast to images of microscopic organisms. The 'TX-510' employs a ZrO/W(100) Schottky emitter and an 'In-Lens Field Emission Gun'. The key points of the improvements are (1) reduced spherical aberration coefficient of magnetic objective lens, (2) easy and accurate focusing, (3) newly designed astigmatism compensator, (4) segmented thin film target for interchanging the target materials by electron beam shift and (5) fluorescent X-ray analysis system.

  10. Understanding reconstructed Dante spectra using high resolution spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    May, M. J., E-mail: may13@llnl.gov; Widmann, K.; Kemp, G. E.; Thorn, D.; Colvin, J. D.; Schneider, M. B.; Moore, A.; Blue, B. E. [L-170 Lawrence Livermore National Laboratory, 7000 East Ave., Livermore, California 94551 (United States); Weaver, J. [Naval Research Laboratory, 4555 Overlook Ave. SW, Washington, DC 20375 (United States)

    2016-11-15

    The Dante is an 18 channel filtered diode array used at the National Ignition Facility (NIF) to measure the spectrally and temporally resolved radiation flux between 50 eV and 20 keV from various targets. The absolute flux is determined from the radiometric calibration of the x-ray diodes, filters, and mirrors and a reconstruction algorithm applied to the recorded voltages from each channel. The reconstructed spectra are very low resolution with features consistent with the instrument response and are not necessarily consistent with the spectral emission features from the plasma. Errors may exist between the reconstructed spectra and the actual emission features due to assumptions in the algorithm. Recently, a high resolution convex crystal spectrometer, VIRGIL, has been installed at NIF with the same line of sight as the Dante. Spectra from L-shell Ag and Xe have been recorded by both VIRGIL and Dante. Comparisons of these two spectroscopic measurements yield insights into the accuracy of the Dante reconstructions.

  11. TH-AB-209-07: High Resolution X-Ray-Induced Acoustic Computed Tomography

    Energy Technology Data Exchange (ETDEWEB)

    Xiang, L; Tang, S [University of Oklahoma, Norman, OK (United States); Ahmad, M [Stanford University, Palo Alto, CA (United States); Xing, L [Stanford University School of Medicine, Stanford, CA (United States)

    2016-06-15

    Purpose: X-ray radiographic absorption imaging is an invaluable tool in medical diagnostics, biology and materials science. However, the use of conventional CT is limited by two factors: the detection sensitivity to weak absorption material and the radiation dose from CT scanning. The purpose of this study is to explore X-ray induced acoustic computed tomography (XACT), a new imaging modality, which combines X-ray absorption contrast and high ultrasonic resolution to address these challenges. Methods: First, theoretical models was built to analyze the XACT sensitivity to X-ray absorption and calculate the minimal radiation dose in XACT imaging. Then, an XACT system comprised of an ultrashort X-ray pulse, a low noise ultrasound detector and a signal acquisition system was built to evaluate the X-ray induced acoustic signal generation. A piece of chicken bone and a phantom with two golden fiducial markers were exposed to 270 kVp X-ray source with 60 ns exposure time, and the X-ray induced acoustic signal was received by a 2.25MHz ultrasound transducer in 200 positions. XACT images were reconstructed by a filtered back-projection algorithm. Results: The theoretical analysis shows that X-ray induced acoustic signals have 100% relative sensitivity to X-ray absorption, but not to X-ray scattering. Applying this innovative technology to breast imaging, we can reduce radiation dose by a factor of 50 compared with newly FDA approved breast CT. The reconstructed images of chicken bone and golden fiducial marker phantom reveal that the spatial resolution of the built XACT system is 350µm. Conclusion: In XACT, the imaging sensitivity to X-ray absorption is improved and the imaging dose is dramatically reduced by using ultrashort pulsed X-ray. Taking advantage of the high ultrasonic resolution, we can also perform 3D imaging with a single X-ray pulse. This new modality has the potential to revolutionize x-ray imaging applications in medicine and biology.

  12. Krypton K-shell X-ray spectra recorded by the HENEX spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Seely, J.F. [Naval Research Laboratory, Space Science Division, Washington DC 20375 (United States)]. E-mail: john.seely@nrl.navy.mil; Back, C.A. [Lawrence Livermore National Laboratory, Livermore CA 94550 (United States); Constantin, C. [Lawrence Livermore National Laboratory, Livermore CA 94550 (United States); Lee, R.W. [Lawrence Livermore National Laboratory, Livermore CA 94550 (United States); Chung, H.-K. [Lawrence Livermore National Laboratory, Livermore CA 94550 (United States); Hudson, L.T. [National Institute of Standards and Technology, Gaithersburg MD 20899 (United States); Szabo, C.I. [National Institute of Standards and Technology, Gaithersburg MD 20899 (United States); Henins, A. [National Institute of Standards and Technology, Gaithersburg MD 20899 (United States); Holland, G.E. [SFA Inc., 9315 Largo Drive West Suite 200, Largo MD 20774 (United States); Atkin, R. [Tiger Innovations, L.L.C., 3610 Vacation Lane, Arlington VA 22207 (United States); Marlin, L. [Naval Research Laboratory, Space Science Division, Washington DC 20375 (United States)

    2006-05-15

    High-resolution X-ray spectra were recorded by the High-Energy Electronic X-ray (HENEX) spectrometer from a variety of targets irradiated by the Omega laser at the Laboratory for Laser Energetics. The HENEX spectrometer utilizes four reflection crystals covering the 1-20keV energy range and one quartz(10-11) transmission crystal (Laue geometry) covering the 11-40keV range. The time-integrated spectral images were recorded on five CMOS X-ray detectors. In the spectra recorded from krypton-filled gasbag and hohlraum targets, the helium-like K-shell transitions n=1-2, 1-3, and 1-4 appeared in the 13-17keV energy range. A number of additional spectral features were observed at energies lower than the helium-like n=1-3 and n=1-4 transitions. Based on computational simulations of the spectra using the FLYCHK/FLYSPEC codes, which included opacity effects, these additional features are identified to be inner-shell transitions from the Li-like through N-like krypton charge states. The comparisons of the calculated and observed spectra indicate that these transitions are characteristic of the plasma conditions immediately after the laser pulse when the krypton density is 2x10{sup 18}cm{sup -3} and the electron temperature is in the range 2.8-3.2keV. These spectral features represent a new diagnostic for the charge state distribution, the density and electron temperature, and the plasma opacity. Laboratory experiments indicate that it is feasible to record K-shell spectra from gold and higher Z targets in the >60keV energy range using a Ge(220) transmission crystal.

  13. High-resolution bent-crystal spectrometer for the ultra-soft x-ray region

    International Nuclear Information System (INIS)

    Beiersdorfer, P.; von Goeler, S.; Bitter, M.; Hill, K.W.; Hulse, R.A.; Walling, R.S.

    1988-10-01

    A multichannel vacuum Brag-crystal spectrometer has been developed for high-resolution measurements of the line emission from tokamak plasmas in the wavelength region between 4 and 25 /angstrom/. The spectrometer employs a bent crystal in Johann geometry and a microchannel-plate intensified photodiode array. The instrument is capable of measuring high-resolution spectra (λ/Δλ ∼ 3000) with fast time resolution (4 msec per spectrum) and good spatial resolution (3 cm). The spectral bandwidth is Δλ/λ 0 = 8/angstrom/. A simple tilt mechanism allows access to different wavelength intervals. In order to illustrate the utility of the new spectrometer, time- and space-resolved measurements of the n = 3 to n = 2 spectrum of selenium from the Princeton Large Torus tokamak plasmas are presented. The data are used to determine the plasma transport parameters and to infer the radial distribution of fluorinelike, neonlike, and sodiumlike ions of selenium in the plasma. The new ultra-soft x-ray spectrometer has thus enabled us to demonstrate the utility of high-resolution L-shell spectroscopy of neonlike ions as a fusion diagnostic. 43 refs., 23 figs

  14. 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.

  15. 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.

  16. Fine-pitch glass GEM for high-resolution X-ray imaging

    International Nuclear Information System (INIS)

    Fujiwara, T.; Toyokawa, H.; Mitsuya, Y.

    2016-01-01

    We have developed a fine-pitch glass gas electron multiplier (G-GEM) for high-resolution X-ray imaging. The fine-pitch G-GEM is made of a 400 μm thick photo-etchable glass substrate with 150 μm pitch holes. It is fabricated using the same wet etching technique as that for the standard G-GEM. In this work, we present the experimental results obtained with a single fine-pitch G-GEM with a 50 × 50 mm 2 effective area. We recorded an energy resolution of 16.2% and gas gain up to 5,500 when the detector was irradiated with 5.9 keV X-rays. We present a 50 × 50 mm 2 X-ray radiograph image acquired with a scintillation gas and optical readout system.

  17. Unattented mode monitoring of high resolution gamma-ray spectra

    International Nuclear Information System (INIS)

    Smith, B.G.R.; Van Dyck, P.; Debraix, P.

    1991-01-01

    An Isotope Monitoring System (IMS) for unattended spectrum acquisition is described. This consists of a simple low cost flexible software package running on a Compaq 80386 and controlling up to 4 Canberra Packard System 100 multi-channel analyzer (MCA) cards. The IMS permits the independent configuration of each of the 4 MCA cards for different monitoring cycles and for different spectrum acquisition cycles each being based upon different trigger criteria. In this way IMS is able to automatically identify events, time tag them, and acquire and store valid spectra corresponding to those event. An additional feature of IMS permits to run a Multigroup Analysis (MGA) software package for the determination of plutonium isotopic compositions in batch mode. One particular application is discussed which consists of 4 high resolution gamma-ray detector systems connected together to the IMS for unattended spectrum acquisition. The off-line batch mode analysis of the spectra using MGA is also discussed

  18. Modern Progress and Modern Problems in High Resolution X-ray Absorption from the Cold Interstellar Medium

    Science.gov (United States)

    Corrales, Lia; Li, Haochuan; Heinz, Sebastian

    2018-01-01

    With accurate cross-sections and higher signal-to-noise, X-ray spectroscopy can directly measure Milky Way gas and dust-phase metal abundances with few underlying assumptions. The X-ray energy band is sensitive to absorption by all abundant interstellar metals — carbon, oxygen, neon, silicon, magnesium, and iron — whether they are in gas or dust form. High resolution X-ray spectra from Galactic X-ray point sources can be used to directly measure metal abundances from all phases of the interstellar medium (ISM) along singular sight lines. We show our progress for measuring the depth of photoelectric absorption edges from neutral ISM metals, using all the observations of bright Galactic X-ray binaries available in the Chandra HETG archive. The cross-sections we use take into account both the absorption and scattering effects by interstellar dust grains on the iron and silicate spectral features. However, there are many open problems for reconciling X-ray absorption spectroscopy with ISM observations in other wavelengths. We will review the state of the field, lab measurements needed, and ways in which the next generation of X-ray telescopes will contribute.

  19. High-resolution Al L2,3-edge x-ray absorption near edge structure spectra of Al-containing crystals and glasses: coordination number and bonding information from edge components

    International Nuclear Information System (INIS)

    Weigel, C; Calas, G; Cormier, L; Galoisy, L; Henderson, G S

    2008-01-01

    High-resolution Al L 2,3 -edge x-ray absorption near edge structure (XANES) spectra have been measured in selected materials containing aluminium in 4-, 5- and 6-coordination. A shift of 1.5 eV is observed between the onset of [4] Al and [6] Al L 2,3 -edge XANES, in agreement with the magnitude of the shift observed at the Al K-edge. The differences in the position and shape of low-energy components of Al L 2,3 -edge XANES spectra provide a unique fingerprint of the geometry of the Al site and of the nature of Al-O chemical bond. The high resolution allows the calculation of electronic parameters such as the spin-orbit coupling and exchange energy using intermediate coupling theory. The electron-hole exchange energy decreases in tetrahedral as compared to octahedral symmetry, in relation with the increased screening of the core hole in the former. Al L 2,3 -edge XANES spectra confirm a major structural difference between glassy and crystalline NaAlSi 2 O 6 , with Al in 4- and 6-coordination, respectively, Al coordination remaining unchanged in NaAl 1-x Fe x Si 2 O 6 glasses, as Fe is substituted for Al

  20. Computerized tomography using high resolution X-ray imaging system with a microfocus source

    International Nuclear Information System (INIS)

    Zaprazny, Z.; Korytar, D.; Konopka, P.; Ac, V.; Bielecki, J.

    2011-01-01

    In recent years there is an effort to image an internal structure of an object by using not only conventional 2D X-ray radiography but also using high resolution 3D tomography which is based on reconstruction of multiple 2D projections at various angular positions of the object. We have previously reported [1] the development and basic parameters of a high resolution x-ray imaging system with a microfocus source. We report the recent progress using this high resolution X-ray laboratory system in this work. These first findings show that our system is particularly suitable for light weight and nonmetallic objects such as biological objects, plastics, wood, paper, etc. where phase contrast helps to increase the visibility of the finest structures of the object. Phase-contrast X-ray Computerized Tomography is of our special interest because it is an emerging imaging technique that can be implemented at third generation synchrotron radiation sources and also in laboratory conditions using a microfocus X-ray tube or beam conditioning optics. (authors)

  1. High-resolution X-ray crystal structure of bovine H-protein using the high-pressure cryocooling method.

    Science.gov (United States)

    Higashiura, Akifumi; Ohta, Kazunori; Masaki, Mika; Sato, Masaru; Inaka, Koji; Tanaka, Hiroaki; Nakagawa, Atsushi

    2013-11-01

    Recently, many technical improvements in macromolecular X-ray crystallography have increased the number of structures deposited in the Protein Data Bank and improved the resolution limit of protein structures. Almost all high-resolution structures have been determined using a synchrotron radiation source in conjunction with cryocooling techniques, which are required in order to minimize radiation damage. However, optimization of cryoprotectant conditions is a time-consuming and difficult step. To overcome this problem, the high-pressure cryocooling method was developed (Kim et al., 2005) and successfully applied to many protein-structure analyses. In this report, using the high-pressure cryocooling method, the X-ray crystal structure of bovine H-protein was determined at 0.86 Å resolution. Structural comparisons between high- and ambient-pressure cryocooled crystals at ultra-high resolution illustrate the versatility of this technique. This is the first ultra-high-resolution X-ray structure obtained using the high-pressure cryocooling method.

  2. THE XMM-NEWTON X-RAY SPECTRA OF THE MOST X-RAY LUMINOUS RADIO-QUIET ROSAT BRIGHT SURVEY-QSOs: A REFERENCE SAMPLE FOR THE INTERPRETATION OF HIGH-REDSHIFT QSO SPECTRA

    International Nuclear Information System (INIS)

    Krumpe, M.; Markowitz, A.; Lamer, G.; Corral, A.

    2010-01-01

    We present the broadband X-ray properties of four of the most X-ray luminous (L X ≥ 10 45 erg s -1 in the 0.5-2 keV band) radio-quiet QSOs found in the ROSAT Bright Survey. This uniform sample class, which explores the extreme end of the QSO luminosity function, exhibits surprisingly homogenous X-ray spectral properties: a soft excess with an extremely smooth shape containing no obvious discrete features, a hard power law above 2 keV, and a weak narrow/barely resolved Fe Kα fluorescence line for the three high signal-to-noise ratio (S/N) spectra. The soft excess can be well fitted with only a soft power law. No signatures of warm or cold intrinsic absorbers are found. The Fe Kα centroids and the line widths indicate emission from neutral Fe (E = 6.4 keV) originating from cold material from distances of only a few light days or further out. The well-constrained equivalent widths (EW) of the neutral Fe lines are higher than expected from the X-ray Baldwin effect which has been only poorly constrained at very high luminosities. Taking into account our individual EW measurements, we show that the X-ray Baldwin effect flattens above L X ∼ 10 44 erg s -1 (2-10 keV band) where an almost constant (EW) of ∼100 eV is found. We confirm the assumption of having very similar X-ray active galactic nucleus properties when interpreting stacked X-ray spectra. Our stacked spectrum serves as a superb reference for the interpretation of low S/N spectra of radio-quiet QSOs with similar luminosities at higher redshifts routinely detected by XMM-Newton and Chandra surveys.

  3. Application of high resolution x-ray spectrometry preceded by neutron activation for elemental analysis of soil samples

    International Nuclear Information System (INIS)

    Hernandez Rivero, A.; Capote Rodriguez, G.; Herrera Peraza, E.

    1996-01-01

    Utilization of High Resolution X-Ray Spectrometry preceded by activation of the samples by irradiation with neutron fluxes (NAA R X) is a relatively modern trend in application of nuclear techniques. This method may complement advantageously the usual Neutron Activation Analysis by means of Gamma Spectrometry (NAA-G) In this work results obtained by the application of NAA-RX for non-destructive analysis of Cuban soil samples are discussed. The samples were irradiated with reactor neutron fluxes and the induced characteristic X-rays were measured by using Si(li)-detector. Concentrations of Fe, Zn and Eu as determined by NAA-RX are compared with both NAA-G and XRF data. For the elaboration of X-ray and Gamma Spectra the computer programs AXIL and ACTAN were used respectively

  4. A hard x-ray spectrometer for high angular resolution observations of cosmic sources

    International Nuclear Information System (INIS)

    Hailey, C.J.; Ziock, K.P.; Harrison, F.; Kahn, S.M.; Liedahl, D.; Lubin, P.M.; Seiffert, M.

    1988-01-01

    LAXRIS (large area x-ray imaging spectrometer) is an experimental, balloon-borne, hard x-ray telescope that consists of a coaligned array of x-ray imaging spectrometer modules capable of obtaining high angular resolution (1--3 arcminutes) with moderate energy resolution in the 20- to 300-keV region. Each spectrometer module consists of a CsI(Na) crystal coupled to a position-sensitive phototube with a crossed-wire, resistive readout. Imaging is provided by a coded aperture mask with a 4-m focal length. The high angular resolution is coupled with rather large area (/approximately/800 cm 2 ) to provide good sensitivity. Results are presented on performance and overall design. Sensitivity estimates are derived from a Monte-Carlo code developed to model the LAXRIS response to background encountered at balloon altitudes. We discuss a variety of observations made feasible by high angular resolution. For instance, spatially resolving the nonthermal x-ray emission from clusters of galaxies is suggested as an ideal program for LAXRIS. 15 refs., 5 figs

  5. High resolution solar soft X-ray spectrometer

    International Nuclear Information System (INIS)

    Zhang Fei; Wang Huanyu; Peng Wenxi; Liang Xiaohua; Zhang Chunlei; Cao Xuelei; Jiang Weichun; Zhang Jiayu; Cui Xingzhu

    2012-01-01

    A high resolution solar soft X-ray spectrometer (SOX) payload onboard a satellite is developed. A silicon drift detector (SDD) is adopted as the detector of the SOX spectrometer. The spectrometer consists of the detectors and their readout electronics, a data acquisition unit and a payload data handling unit. A ground test system is also developed to test SOX. The test results show that the design goals of the spectrometer system have been achieved. (authors)

  6. High resolution X-ray diffraction studies on unirradiated

    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 ...

  7. High-resolution 3D imaging of polymerized photonic crystals by lab-based x-ray nanotomography with 50-nm resolution

    Science.gov (United States)

    Yin, Leilei; Chen, Ying-Chieh; Gelb, Jeff; Stevenson, Darren M.; Braun, Paul A.

    2010-09-01

    High resolution x-ray computed tomography is a powerful non-destructive 3-D imaging method. It can offer superior resolution on objects that are opaque or low contrast for optical microscopy. Synchrotron based x-ray computed tomography systems have been available for scientific research, but remain difficult to access for broader users. This work introduces a lab-based high-resolution x-ray nanotomography system with 50nm resolution in absorption and Zernike phase contrast modes. Using this system, we have demonstrated high quality 3-D images of polymerized photonic crystals which have been analyzed for band gap structures. The isotropic volumetric data shows excellent consistency with other characterization results.

  8. Very high resolution UV and X-ray spectroscopy and imagery of solar active regions

    Science.gov (United States)

    Bruner, M.; Brown, W. A.; Haisch, B. M.

    1987-01-01

    A scientific investigation of the physics of the solar atmosphere, which uses the techniques of high resolution soft X-ray spectroscopy and high resolution UV imagery, is described. The experiments were conducted during a series of three sounding rocket flights. All three flights yielded excellent images in the UV range, showing unprecedented spatial resolution. The second flight recorded the X-ray spectrum of a solar flare, and the third that of an active region. A normal incidence multi-layer mirror was used during the third flight to make the first astronomical X-ray observations using this new technique.

  9. Diagnostic Spectrometers for High Energy Density X-Ray Sources

    International Nuclear Information System (INIS)

    Hudson, L. T.; Henins, A.; Seely, J. F.; Holland, G. E.

    2007-01-01

    -dispersive techniques. These efforts inform the optimization of diagnostic designs that will permit acquisition of high-resolution, hard x-ray spectra in the HED environment

  10. High resolution X-ray spectra of solar flares. V. interpretation of inner-shell transitions in Fe XX-Fe XXIII

    International Nuclear Information System (INIS)

    Doschek, G.A.; Feldman, U.; Cowan, R.D.

    1981-01-01

    We discuss high-resolution solar flare iron line spectra recorded between 1.82 and 1.97 A by a spectrometer flown by the Naval Research Laboratory on an Air Force spacecraft launched on 1979 February 24. The emission line spectrum is due to inner-shell transitions in the ions Fe XX-Fe XXV. Using theoretical spectra and calculations of line intensities obtained by methods discussed by Merts, Cowan, and Magee, we derive electron temperatures as a function for time of two large class X flares. These temperatures are deduced from intensities of lines of Fe XXIII, Fe XXII, and Fe XXIV. Previous measurements by us have involved only lines of Fe XXIV and Fe XXV. We discuss the determination of the differential emission measure between about 12 x 10 6 K and 20 x 10 6 K using these temperatures. The possibility of determining electron densities in flare and tokamak plasmas using the inner-shell spectra of Fe XXI and Fe XX is discussed. We also discuss recent theoretical work by Mewe and Schrijver based on atomic data of Grineva, Safronova, and Urnov

  11. High-resolution x-ray spectroscopy of coherent bremsstrahlung fine structure

    International Nuclear Information System (INIS)

    Lund, M.W.

    1989-01-01

    The aim of this research was to provide experimental evidence for fine structure due to umklapp by distinct reciprocal lattice vectors in coherent bremsstrahlung spectra. The spontaneous emission of photons by relativistic electrons transversing thin crystals is made possible by recoil of the crystal, which absorbs momentum in multiples of ℎG where G is a reciprocal lattice vector. Previous work in the MeV-GeV beam energy range used detectors whose energy resolution was greater than 10%. By fitting a Johann wavelength dispersive spectrometer to a transmission electron microscope the author obtained coherent bremsstrahlung spectra of very high quality with energy resolution of 1%. Important to this result were also the fine angular collimation, small energy width of the electron beam in the microscope, and the accurate control of crystal orientation possible in a modern goniometer stage. The theory of the design of bent crystal x-ray spectrometers is extended to include effects of defocus and aberrations. The theory for diffraction from a stationary three dimensional grating due to a dipole radiator moving at relativistic speeds is derived as well as several other broadening mechanisms stemming from experimental variables. This dissertation provides the first experimental observations and corresponding theoretical background for the fine structure of coherent bremsstrahlung due to umklapp by different G-vectors in the same reciprocal lattice plane

  12. Application of high resolution x-ray spectrometry preceded by neutron activation for elemental analysis of soil samples

    International Nuclear Information System (INIS)

    Hernandez Rivero, A.; Capote Rodriguez, G.; Padilla Alvarez, R.; Herrera Peraza, E.

    1997-01-01

    Utilization of High Resolution X-Ray Spectrometry preceded by activation of the samples by irradiation with neutron fluxes (NAA-RX) is a relatively modern trend in application of nuclear techniques. This method may complement advantageously the usual Neutron Activation Analysis by means of Gamma Spectrometry (NAA-G). In this work results obtained by the application of NAA-RX for non-destructive analysis of Cuban soil samples are discussed. The samples were irradiated with reactor neutron fluxes and the induced characteristic X-rays were measured by using Si(Li)-detector. Concentrations of Fe, Zn and Eu as determined by NAA-RX are compared with both NAA-G and XRF data. For the elaboration of X-Ray and Gamma Spectra the computer programs AXIL and ACTAN were used respectively. (author) [es

  13. On the limitations and optimisation of high-resolution 3D medical X-ray imaging systems

    International Nuclear Information System (INIS)

    Zhou Shuang; Brahme, Anders

    2011-01-01

    Based on a quantitative analysis of both attenuation and refractive properties of X-ray propagation in human body tissues and the introduction of a mathematical model for image quality analysis, some limitations and optimisation of high-resolution three-dimensional (3D) medical X-ray imaging techniques are studied. A comparison is made of conventional attenuation-based X-ray imaging methods with the phase-contrast X-ray imaging modalities that have been developed recently. The results indicate that it is theoretically possible through optimal design of the X-ray imaging system to achieve high spatial resolution (<100 μm) in 3D medical X-ray imaging of the human body at a clinically acceptable dose level (<10 mGy) by introducing a phase-contrast X-ray imaging technique.

  14. X-ray High-resolution Spectroscopy for Laser-produced Plasma

    Science.gov (United States)

    Barbato, F.; Scarpellini, D.; Malizia, A.; Gaudio, P.; Richetta, M.; Antonelli, L.

    The study of the emission spectrum gives information about the material generating the spectrum itself and the condition in which this is generated. The wavelength spectra lines are linked to the specific element and plasma conditions (electron temperature, density), while their shape is influenced by several physical effects like Stark and Doppler ones. In this work we study the X-ray emission spectra of a copper laser-produced plasma by using a spherical bent crystal spectrometer to measure the electron temperature. The facility used is the laser TVLPS, at the Tor Vergata University in Rome. It consists of a Nd:Glass source (in first harmonic - 1064 nm) whose pulse parameters are: 8 J in energy, time duration of 15 ns and a focal spot diameter of 200 μm. The adopted spectrometer is based on a spherical bent crystal of muscovite. The device combines the focusing property of a spherical mirror with the Bragg's law. This allows to obtain a great power resolution but a limited range of analysis. In our case the resolution is on average 80 eV. As it is well-known, the position of the detector on the Rowland's circle is linked to the specific spectral range which has been studied. To select the area to be investigated, we acquired spectra by means of a flat spectrometer. The selected area is centered on 8.88 Å. To calibrate the spectrum we wrote a ray-tracing MATLAB code, which calculates the detector alignment parameters and calibration curve. We used the method of line ratio to measure the electron temperature. This is possible because we assumed the plasma to be in LTE condition. The temperature value was obtained comparing the experimental one, given by the line ratio, with the theoretical one, preceded by FLYCHK simulations.

  15. High spectral resolution measurements of a solar flare hard X-ray burst

    International Nuclear Information System (INIS)

    Lin, R.P.; Schwartz, R.A.; NASA, Goddard Space Flight Center, Greenbelt, MD)

    1987-01-01

    Observations are reported of an intense solar flare hard X-ray burst on June 27, 1980, made with a balloon-borne array of liquid nitrogen-cooled Ge detector which provided unprecedented spectral resolution (no more than 1 keV FWHM). The hard X-ray spectra throughout the impulsive phase burst fitted well to a double power-law form, and emission from an isothermal 0.1-1 billion K plasma can be specifically excluded. The temporal variations of the spectrum indicate that the hard X-ray burst is made up of two superposed components: individual spikes lasting about 3-15 sec, which have a hard spectrum and a break energy of 30-65 keV; and a slowly varying component characterized by a soft spectrum with a constant low-energy slope and a break energy which increases from 25 kev to at least 100 keV through the event. The double power-law shape indicates that DC electric field acceleration, similar to that occurring in the earth's auroral zone, may be the source of the energetic electrons which produce the hard X-ray emission. 39 references

  16. Development of the super high angular resolution principle for X-ray imaging

    International Nuclear Information System (INIS)

    Zhang Chen; Zhang Shuangnan

    2011-01-01

    Development of the Super High Angular Resolution Principle (SHARP) for coded-mask X-ray imaging is presented. We prove that SHARP can be considered as a generalized coded mask imaging method with a coding pattern comprised of diffraction-interference fringes in the mask pattern. The angular resolution of SHARP can be improved by detecting the fringes more precisely than the mask's element size, i.e. by using a detector with a pixel size smaller than the mask's element size. The proposed mission SHARP-X for solar X-ray observations is also briefly discussed. (research papers)

  17. Diversity of soft X-ray spectra in quasars

    International Nuclear Information System (INIS)

    Elvis, M.; Wilkes, B.J.; Tananbaum, H.

    1985-01-01

    Soft X-ray spectra for three quasars obtained with the Einstein Imaging Proportional Counter covering the 0.1-4.0 keV band are reported. Power-law fits to these spectra have best-fit energy indices of 1.2 +0.6 or -0.2, for the quasar NAB 0205 + 024, 0.6 +0.3 or -0.2 for the quasar B2 1028 + 313, and 2.2 + or -0.4 for the quasar PG 1211 + 143. None of the quasars shows any evidence for a column density of cold matter in excess of the galactic values. The derived spectra demonstrate that there is no single universal power law slope for quasar X-ray spectra. The implications of these results for the X-ray background, X-ray continuum emission mechanisms, and the production of the optical/UV emission lines are briefly discussed. 46 references

  18. Experimental demonstration of high resolution three-dimensional x-ray holography

    International Nuclear Information System (INIS)

    McNulty, I.; Trebes, J.E.; Brase, J.M.; Yorkey, T.J.; Levesque, R.; Szoke, H.; Anderson, E.H.; Jacobsen, C.

    1992-01-01

    Tomographic x-ray holography may make possible the imaging of biological objects at high resolution in three dimensions. We performed a demonstration experiment with soft x-rays to explore the feasibility of this technique. Coherent 3.2-nm undulator radiation was used to record Fourier transform holograms of a microfabricated test object from various illumination angles. The holograms were numerically reconstructed according to the principles of diffraction tomography, yielding images of the object that are well resolved in three dimensions

  19. Monte Carlo simulation of x-ray spectra in mammography

    Energy Technology Data Exchange (ETDEWEB)

    Ng, K.P. [Department of Optometry and Radiography, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong (China). E-mail: benngkp at netvigator.com; Kwok, C.S.; Ng, K.P.; Tang, F.H. [Department of Optometry and Radiography, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong (China)

    2000-05-01

    A model for generating x-ray spectra in mammography is presented. This model used the ITS version 3 Monte Carlo code for simulating the radiation transport. Various target/filter combinations such as tungsten/aluminium, molybdenum/molybdenum, molybdenum/rhodium and rhodium/rhodium were used in the simulation. Both bremsstrahlung and characteristic x-ray production were included in the model. The simulated x-ray emission spectra were compared with two sets of spectra, those of Boone et al (1997 Med. Phys. 24 1863-74) and IPEM report 78. The {chi}{sup 2} test was used for the overall goodness of fit of the spectral data. There is good agreement between the simulated x-ray spectra and the comparison spectra as the test yielded a probability value of nearly 1. When the transmitted x-ray spectra for specific target/filter combinations were generated and compared with a measured molybdenum/rhodium spectrum and spectra generated in IPEM report 78, close agreement is also observed. This was demonstrated by the probability value for the {chi}{sup 2} test being almost 1 for all the cases. However, minor differences between the simulated spectra and the 'standard' ones are observed. (author)

  20. Monte Carlo simulation of x-ray spectra in mammography

    International Nuclear Information System (INIS)

    Ng, K.P.

    2000-01-01

    A model for generating x-ray spectra in mammography is presented. This model used the ITS version 3 Monte Carlo code for simulating the radiation transport. Various target/filter combinations such as tungsten/aluminium, molybdenum/molybdenum, molybdenum/rhodium and rhodium/rhodium were used in the simulation. Both bremsstrahlung and characteristic x-ray production were included in the model. The simulated x-ray emission spectra were compared with two sets of spectra, those of Boone et al (1997 Med. Phys. 24 1863-74) and IPEM report 78. The χ 2 test was used for the overall goodness of fit of the spectral data. There is good agreement between the simulated x-ray spectra and the comparison spectra as the test yielded a probability value of nearly 1. When the transmitted x-ray spectra for specific target/filter combinations were generated and compared with a measured molybdenum/rhodium spectrum and spectra generated in IPEM report 78, close agreement is also observed. This was demonstrated by the probability value for the χ 2 test being almost 1 for all the cases. However, minor differences between the simulated spectra and the 'standard' ones are observed. (author)

  1. Ultra high resolution X-ray detectors

    International Nuclear Information System (INIS)

    Hess, U.; Buehler, M.; Hentig, R. von; Hertrich, T.; Phelan, K.; Wernicke, D.; Hoehne, J.

    2001-01-01

    CSP Cryogenic Spectrometers GmbH is developing cryogenic energy dispersive X-ray spectrometers based on superconducting detector technology. Superconducting sensors exhibit at least a 10-fold improvement in energy resolution due to their low energy gap compared to conventional Si(Li) or Ge detectors. These capabilities are extremely valuable for the analysis of light elements and in general for the analysis of the low energy range of the X-ray spectrum. The spectrometer is based on a mechanical cooler needing no liquid coolants and an adiabatic demagnetization refrigerator (ADR) stage which supplies the operating temperature of below 100 mK for the superconducting sensor. Applications include surface analysis in semiconductor industry as well material analysis for material composition e.g. in ceramics or automobile industry

  2. Indirect measure of X-rays spectra using TLDs

    International Nuclear Information System (INIS)

    Bonzi, E. V.; Mainardi, R. T.

    2011-10-01

    A methodology of indirect measure of X-rays spectra, emitted by conventional tubes, was developed recently and its feasibility verified in the first place by Monte Carlo simulations. For that case is intended to measure, by means of plastic scintillators, attenuation curves of dispersed beams previously. In this work were carried out measurements of attenuation curves with thermoluminescent dosimeters (TLD) to verify the kindness of the indirect measure method. The attenuation curve was also measured using an ionization chamber brand Capintec (model 192) with the purpose of making a comparison. The results of the attenuation curve measured with both dosimeters present a good resolution inside the statistical fluctuations and the spectral reconstruction using diverse parametric functions is carried out in a quick and simple way with excellent resolutions in the functional form. For this reconstruction method are of fundamental importance the following properties of the used dosimeter: in the first place the repetition of the measures, property that could check; in second place the precision of the measured data and lastly the dosimeter response, this is, the increase of the thermoluminescent signal before an increase of the photons flow of X-rays. This parameter is the gradient of the curve thermoluminescent signal versus the dose imparted to the dosimeter. The measures were realized with a generator of X-rays brand Kevex provided of a conventional tube with tungsten anti cathode that polarizes with high tension to a maximum value of 50 kV and current of 0.5 ma. (Author)

  3. Laboratory Studies of X-ray Spectra Formed by Charge Exchange

    Science.gov (United States)

    Beiersdorfer, Peter; Ali, R.; Brown, G. V.; Koutroumpa, D.; Kelley, R. L.; Kilbourne, C.; Leutenegger, M. A.; Porter, F.

    2013-04-01

    Charge exchange between ions and neutral atoms or molecules has been accepted at an important soft producing process in our solar system. By extension, charge exchange may contribute to the X-ray emission of circumstellar material. It may also produce X-ray emission at the boundaries of supernova ejecta and star burst galaxies, or whenever hot plasma collides with neutral matter. X-ray spectra of K-shell and L-shell ions formed by charge exchange have now been studied in a variety of laboratory settings. These experiments have shown several characteristic features of line formation by charge exchange when compared to the X-ray emission produced by electron-impact excitation, e.g., enhancement emission of forbidden lines and of lines from levels with high principal quantum number. They have also shown a dependence on the interaction gas and on the energy of the ion-neutral collision. Moreover, the transfer of multiple electrons is typically preferred, provided the donor molecules or atoms have multiple valence-shell electrons. The laboratory measurements are in qualitative agreement with theory. However, the details of the observed X-ray spectra, especially those recorded with high spectral resolution, can differ substantially from predictions, especially for spectra produced at collision velocities equal to or lower than those found in thermal plasmas or produced with neutral gases other than atomic hydrogen. Puzzling discrepancies can be noted, such as enhanced emission from an upper level with the 'wrong' principal quantum number. Even more puzzling is a recent experiment in which two, co-mixed bare ion species of similar atomic number produce very different Lyman series emission upon charge exchange with a given neutral gas, defying both theoretical predictions and empirical scaling. Laboratory measurements have also shown that some of the characteristic features of charge exchange can be reproduced by radiative electron capture, i.e., by capture of a continuum

  4. X-ray scattering in X-ray fluorescence spectra with X-ray tube excitation - Modelling, experiment, and Monte-Carlo simulation

    International Nuclear Information System (INIS)

    Hodoroaba, V.-D.; Radtke, M.; Vincze, L.; Rackwitz, V.; Reuter, D.

    2010-01-01

    X-ray scattering may contribute significantly to the spectral background of X-ray fluorescence (XRF) spectra. Based on metrological measurements carried out with a scanning electron microscope (SEM) having attached a well characterised X-ray source (polychromatic X-ray tube) and a calibrated energy dispersive X-ray spectrometer (EDS) the accuracy of a physical model for X-ray scattering is systematically evaluated for representative samples. The knowledge of the X-ray spectrometer efficiency, but also of the spectrometer response functions makes it possible to define a physical spectral background of XRF spectra. Background subtraction relying on purely mathematical procedures is state-of-the-art. The results produced by the analytical model are at least as reliable as those obtained by Monte-Carlo simulations, even without considering the very challenging contribution of multiple scattering. Special attention has been paid to Compton broadening. Relevant applications of the implementation of the analytical model presented in this paper are the prediction of the limits of detection for particular cases or the determination of the transmission of X-ray polycapillary lenses.

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

    International Nuclear Information System (INIS)

    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

  6. High Resolution Higher Energy X-ray Microscope for Mesoscopic Materials

    International Nuclear Information System (INIS)

    Snigireva, I; Snigirev, A

    2013-01-01

    We developed a novel X-ray microscopy technique to study mesoscopically structured materials, employing compound refractive lenses. The easily seen advantage of lens-based methodology is the possibility to retrieve high resolution diffraction pattern and real-space images in the same experimental setup. Methodologically the proposed approach is similar to the studies of crystals by high resolution transmission electron microscopy. The proposed microscope was applied for studying of mesoscopic materials such as natural and synthetic opals, inverted photonic crystals

  7. A sounding rocket payload for X-ray astronomy employing high-resolution microcalorimeters

    International Nuclear Information System (INIS)

    McCammon, D.; Almy, R.; Deiker, S.; Morgenthaler, J.; Kelley, R.L.; Marshall, F.J.; Moseley, S.H.; Stahle, C.K.; Szymkowiak, A.E.

    1996-01-01

    We have completed a sounding rocket payload that will use a 36 element array of microcalorimeters to obtain a high-resolution spectrum of the diffuse X-ray background between 0.1 and 1 keV. This experiment uses only mechanical collimation of the incoming X-rays, but the cryostat and detector assembly have been designed to be placed at the focus of a conical foil imaging mirror which will be employed on subsequent flights to do spatially resolved spectroscopy of supernova remnants and other extended objects. The detector system is a monolithic array of silicon calorimeters with ion-implanted thermometers and HgTe X-ray absorbers. The 1 mm 2 pixels achieve a resolution of about 8 eV FWHM operating at 60 mK. (orig.)

  8. High-resolution soft x-ray photoionization studies of selected molecules

    International Nuclear Information System (INIS)

    Hudson, E.A.

    1993-08-01

    Near-edge soft x-ray photoionization spectra were measured for CO, SF 6 , H 2 S, and D 2 S in the gas phase, using the Free University of Berlin plane-grating SX-700-II monochromator at the synchrotron radiation source BESSY. Photoionization spectra of carbon monoxide were measured near the carbon and oxygen K edges. Vibrational spacings and bond lengths are derived for several resonances. Results are consistent with equivalent-core model and indicate the different influences of the carbon and oxygen Is core holes. Corresponding spectra of H 2 CO and D 2 CO were also measured. Assignment of complex vibrational structure in valence-shell and Rydberg resonances is facilitated by comparison of spectra for the two isotopic species. Geometric and vibrational parameters are derived for several carbon 1s core-excited states. Isotopic shifts are observed in the energies and linewidths of some core-excited states. Sulfur hexafluoride photoionization spectra, measured near the sulfur L 2,3 edges, show several series of weak, narrow Rydberg resonances. High resolution and good counting statistics allow a complete assignment of these states. Lineshapes of the broad inner-well resonances are analyzed to establish the magnitudes of vibrational and lifetime broadening in these states. Spectra of the H 2 S and D 2 S molecules were also measured near the sulfur L 2,3 edges. Besides lower-energy transitions to inner-well states, a complex manifold of overlapping Rydberg resonances is observed. The rich fine structure of these states arises mainly from removal of orbital degeneracies in molecular field. Additional structure due to vibrational excitations in the final state is identified by comparison of the spectra for the two isotopic species

  9. Structure of Se-rich As-Se glasses by high-resolution x-ray photoelectron spectroscopy

    International Nuclear Information System (INIS)

    Golovchak, R.; Kovalskiy, A.; Miller, A. C.; Jain, H.; Shpotyuk, O.

    2007-01-01

    To establish the validity of various proposed structural models, we have investigated the structure of the binary As x Se 100-x chalcogenide glass family (x≤40) by high-resolution x-ray photoelectron spectroscopy. From the composition dependence of the valence band, the contributions to the density of states from the 4p lone pair electrons of Se and the 4p bonding states and 4s electrons of Se and As are identified in the top part of the band. The analysis of Se 3d and As 3d core-level spectra supports the so-called chain crossing model for the atomic structure of Se-rich As x Se 100-x bulk glasses. The results also indicate small deviations (∼3-8%) from this model, especially for glass compositions with short Se chains (25 40 Se 60 and of Se-Se-Se fragments in a glass with composition x=30 is established

  10. High resolution hard x-ray microscope on a second generation synchrotron source

    International Nuclear Information System (INIS)

    Tian Yangchao; Li Wenjie; Chen Jie; Liu Longhua; Liu Gang; Tian Jinping; Xiong Ying; Tkachuk, Andrei; Gelb, Jeff; Hsu, George; Yun Wenbing

    2008-01-01

    A full-field, transmission x-ray microscope (TXM) operating in the energy range of 7-11 keV has been installed at the U7A beamline at the National Synchrotron Radiation Laboratory, a second generation synchrotron source operating at 0.8 GeV. Although the photon flux at sample position in the operating energy range is significantly low due to its relatively large emittance, the TXM can get high quality x-ray images with a spatial resolution down to 50 nm with acceptable exposure time. This TXM operates in either absorption or Zernike phase contrast mode with similar resolution. This TXM is a powerful analytical tool for a wide range of scientific areas, especially studies on nanoscale phenomena and structural imaging in biology, materials science, and environmental science. We present here the property of the x-ray source, beamline design, and the operation and key optical components of the x-ray TXM. Plans to improve the throughput of the TXM will be discussed.

  11. NiO as a test case for high resolution resonant inelastic soft x-ray scattering

    International Nuclear Information System (INIS)

    Ghiringhelli, G; Matsubara, M; Dallera, C; Fracassi, F; Gusmeroli, R; Piazzalunga, A; Tagliaferri, A; Brookes, N B; Kotani, A; Braicovich, L

    2005-01-01

    Resonant inelastic x-ray scattering (RIXS) at the L 2,3 edges of 3d transition metal compounds has recently become a high resolution spectroscopic technique thanks to improvements in the instrumentation. We have chosen the prototypical case of NiO to explore the various levels of interpretation applicable to L 3 RIXS spectra of strongly correlated electron systems. Starting from a set of experimental data measured across the Ni L 3 absorption edge with 550 meV combined energy resolution, we analyse the rich spectral structure within an atomic framework. The spectra can be separated into dd and charge transfer excitation regions. The dd excitations can be interpreted and well reproduced within a crystal field model. The charge transfer excitations are analysed through the comparison with calculations made in the Anderson impurity model. A series of parameters belonging to the proposed models (crystal field strength, charge transfer energy, hybridization integrals) can thus be extracted in a very direct and unambiguous way

  12. High-resolution X-ray imaging - a powerful nondestructive technique for applications in semiconductor industry

    International Nuclear Information System (INIS)

    Zschech, Ehrenfried; Yun, Wenbing; Schneider, Gerd

    2008-01-01

    The availability of high-brilliance X-ray sources, high-precision X-ray focusing optics and very efficient CCD area detectors has contributed essentially to the development of transmission X-ray microscopy (TXM) and X-ray computed tomography (XCT) with sub-50 nm resolution. Particularly, the fabrication of high aspect ratio Fresnel zone plates with zone widths approaching 15 nm has contributed to the enormous improvement in spatial resolution during the previous years. Currently, Fresnel zone plates give the ability to reach spatial resolutions of 15 to 20 nm in the soft and of about 30 to 50 nm in the hard X-ray energy range. X-ray microscopes with rotating anode X-ray sources that can be installed in an analytical lab next to a semiconductor fab have been developed recently. These unique TXM/XCT systems provide an important new capability of nondestructive 3D imaging of internal circuit structures without destructive sample preparation such as cross sectioning. These lab systems can be used for failure localization in micro- and nanoelectronic structures and devices, e.g., to visualize voids and residuals in on-chip metal interconnects without physical modification of the chip. Synchrotron radiation experiments have been used to study new processes and materials that have to be introduced into the semiconductor industry. The potential of TXM using synchrotron radiation in the soft X-ray energy range is shown for the nondestructive in situ imaging of void evolution in embedded on-chip copper interconnect structures during electromigration and for the imaging of different types of insulating thin films between the on-chip interconnects (spectromicroscopy). (orig.)

  13. On the Weak-Wind Problem in Massive Stars: X-Ray Spectra Reveal a Massive Hot Wind in mu Columbae

    Science.gov (United States)

    Huenemoerder, David P.; Oskinova, Lidia M.; Ignace, Richard; Waldron, Wayne L.; Todt, Helge; Hamaguchi, Kenji; Kitamoto, Shunji

    2012-01-01

    Mu Columbae is a prototypical weak-wind O star for which we have obtained a high-resolution X-ray spectrum with the Chandra LETG/ACIS instrument and a low-resolution spectrum with Suzaku. This allows us, for the first time, to investigate the role of X-rays on the wind structure in a bona fide weak-wind system and to determine whether there actually is a massive hot wind. The X-ray emission measure indicates that the outflow is an order of magnitude greater than that derived from UV lines and is commensurate with the nominal wind-luminosity relationship for O stars. Therefore, the "weak-wind problem"--identified from cool wind UV/optical spectra--is largely resolved by accounting for the hot wind seen in X-rays. From X-ray line profiles, Doppler shifts, and relative strengths, we find that this weak-wind star is typical of other late O dwarfs. The X-ray spectra do not suggest a magnetically confined plasma-the spectrum is soft and lines are broadened; Suzaku spectra confirm the lack of emission above 2 keV. Nor do the relative line shifts and widths suggest any wind decoupling by ions. The He-like triplets indicate that the bulk of the X-ray emission is formed rather close to the star, within five stellar radii. Our results challenge the idea that some OB stars are "weak-wind" stars that deviate from the standard wind-luminosity relationship. The wind is not weak, but it is hot and its bulk is only detectable in X-rays.

  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. High-energy X-ray spectra of Cygnus XR-1 observed from OSO 8

    Science.gov (United States)

    Dolan, J. F.; Crannell, C. J.; Dennis, B. R.; Frost, K. J.; Orwig, L. E.

    1979-01-01

    X-ray spectra of Cygnus XR-1 were measured with the scintillation spectrometer aboard the OSO 8 satellite during a period of one-and-one-half to three weeks in each of the years from 1975 to 1977. Typical spectra of the source between 15 and 250 keV are presented and the spectra are found to be well represented by a single power-law expression whose photon number spectral index is different for the two intensity states that were considered. The observed pivoting effect is consistent with two-temperature accretion disk models of the X-ray emitting region.

  16. Steep Hard-X-ray Spectra Indicate Extremely High Accretion Rates in Weak Emission-Line Quasars

    Science.gov (United States)

    Marlar, Andrea; Shemmer, Ohad; Anderson, Scott F.; Brandt, W. Niel; Diamond-Stanic, Aleksandar M.; Fan, Xiaohui; Luo, Bin; Plotkin, Richard; Richards, Gordon T.; Schneider, Donald P.; Wu, Jianfeng

    2018-06-01

    We present XMM-Newton imaging spectroscopy of ten weak emission-line quasars (WLQs) at 0.928 ≤ z ≤ 3.767, six of which are radio quiet and four which are radio intermediate. The new X-ray data enabled us to measure the hard-X-ray power-law photon index (Γ) in each source with relatively high accuracy. These measurements allowed us to confirm previous reports that WLQs have steeper X-ray spectra, therefore indicating higher accretion rates with respect to "typical" quasars. A comparison between the Γ values of our radio-quiet WLQs and those of a carefully-selected, uniform sample of 84 quasars shows that the first are significantly higher, at the ≥ 3σ level. Collectively, the four radio-intermediate WLQs have lower Γ values with respect to the six radio-quiet WLQs, as may be expected if the spectra of the first group are contaminated by X-ray emission from a jet. These results suggest that, in the absence of significant jet emission along our line of sight, WLQs constitute the extreme high end of the accretion rate distribution in quasars. We detect soft excess emission in our lowest-redshift radio-quiet WLQ, in agreement with previous findings suggesting that the prominence of this feature is associated with a high accretion rate. We have not detected signatures of Compton reflection, Fe Kα lines, or strong variability between two X-ray epochs in any of our WLQs.

  17. X-ray spectra of clusters of galaxies

    Science.gov (United States)

    Sarazin, Craig L.

    1990-01-01

    X-ray line observations of clusters of galaxies have shown that the X-ray emission in clusters is mainly thermal emission from hot diffuse gas, and that much of this gas has come out of stars, probably having been ejected from galaxies in the cluster. Future high resolution observations should allow us to determine the physical state of the gas. X-ray line measurements and abundance determinations can lead to strong constraints on the origin of the intracluster gas, and on the chemical evolution and history of galaxies. Some of the stronger resonant X-ray lines may be observable as absorption lines against a background quasar. Such X-ray absorption line measurement can be used to directly derive distances to clusters, using a technique similar to (and possibly complementary to) that the well-known method using the Zel'dovich-Syunyaev effect.

  18. Chemical effects in x-ray emission spectra

    International Nuclear Information System (INIS)

    Fernandes, N.G.

    1982-01-01

    The chemical bond influence in X-ray emission spectra of hafnium, iodine, iron, sulphur, aluminium and magnesium is detected. The position of one X-ray emission line is determined by three methods: parabolic profile; Gaussian distribution and extra-heavy maximum. (author)

  19. Microbeam high-resolution diffraction and x-ray standing wave methods applied to semiconductor structures

    International Nuclear Information System (INIS)

    Kazimirov, A; Bilderback, D H; Huang, R; Sirenko, A; Ougazzaden, A

    2004-01-01

    A new approach to conditioning x-ray microbeams for high angular resolution x-ray diffraction and scattering techniques is introduced. We combined focusing optics (one-bounce imaging capillary) and post-focusing collimating optics (miniature Si(004) channel-cut crystal) to generate an x-ray microbeam with a size of 10 μm and ultimate angular resolution of 14 μrad. The microbeam was used to analyse the strain in sub-micron thick InGaAsP epitaxial layers grown on an InP(100) substrate by the selective area growth technique in narrow openings between the oxide stripes. For the structures for which the diffraction peaks from the substrate and the film overlap, the x-ray standing wave technique was applied for precise measurements of the strain with a Δd/d resolution of better than 10 -4 . (rapid communication)

  20. Diagnostic x-ray spectra measurements using a silicon surface barrier detector

    International Nuclear Information System (INIS)

    Pani, R.; Laitano, R.F.

    1987-01-01

    A silicon surface barrier detector having a low efficiency for x-ray is used to analyse diagnostic x-ray spectra. This characteristic is advantageous in overcoming experimental problems caused by high fluence rates typical of diagnostic x-ray beams. The pulse height distribution obtained with silicon surface barrier detectors is very different from the true photon spectra because of the presence of escaped Compton photons and the fact that detection efficiency falls abruptly when photon energy increases. A detailed analysis of the spurious effects involved in detection is made by a Monte Carlo method. A stripping procedure is described for implementation on a personal computer. The validity of this method is tested by comparison with experimental results obtained with a Ge detector. The spectra obtained with the Si detector are in fairly good agreement with the analogous spectra measured with a Ge detector. The advantages of using Si as opposed to Ge detectors in x-ray spectrometry are: its simplicity of use, its greater economy for use in routine diagnostic x-ray spectroscopy and the possibility that the stripping procedure can be implemented on a personal computer. (author)

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

    International Nuclear Information System (INIS)

    Song Xiangxia; Zhang Xiaobo; Liu Gang; Cheng Xianchao; Li Wenjie; Guan Yong; Liu Ying; Xiong Ying; Tian Yangchao

    2011-01-01

    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.

  2. High-resolution X-ray spectroscopy of hollow atoms created in plasma heated by subpicosecond laser radiation

    International Nuclear Information System (INIS)

    Faenov, A.Ya.; Magunov, A.I.; Pikuz, T.A.

    1997-01-01

    The investigations of ultrashort (0.4-0.6 ps) laser pulse radiation interaction with solid targets have been carried out. The Trident subpicosecond laser system was used for plasma creation. The X-ray plasma emission was investigated with the help of high-resolution spectrographs with spherically bent mica crystals. It is shown that when high contrast ultrashort laser pulses were used for plasma heating its emission spectra could not be explained in terms of commonly used theoretical models, and transitions in so called hollow atoms must be taken into account for adequate description of plasma radiation

  3. 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...

  4. Spectral and imaging characterization of tabletop X-ray lasers

    Energy Technology Data Exchange (ETDEWEB)

    Dunn, J.; Osterheld, A.L.; Moon, S.J.; Fournier, K.B.; Nilsen, J. [Lawrence Livermore National Lab., CA (United States); Faenov, A.Ya.; Pikuz, T.A.; Skobelev, I.Yu.; Magunov, A.I. [Lawrence Livermore National Lab., CA (United States); MISDC of VNIIFTRI, Mendeleevo (Russian Federation); Shlyaptsev, V.N. [Lawrence Livermore National Lab., CA (United States); California Univ., Davis, CA (United States). DAS

    2001-07-01

    We have performed L-shell spectroscopy and one-dimensional (1-D) imaging of a line focus plasma from a laser-heated Fe polished slab using the tabletop COMET laser system at the Lawrence Livermore National Laboratory. These plasmas are used to generate a Ne-like Fe transient gain X-ray laser that is recorded simultaneously. A spherically-curved crystal spectrometer gives high resolution X-ray spectra of the n=3-2 and n=4-2 resonance lines with 1-D spatial resolution along the line focus. Spectra are presented for different laser pulse conditions. In addition, a variety of X-ray imaging techniques are described. We discuss imaging results from a double-slit X-ray camera with a spherically-curved crystal spectrometer. We show a high resolution Fe K-{alpha} spectrum from the X-ray laser target that indicates the presence of hot electrons in the X-ray laser plasma. (orig.)

  5. Very high resolution UV and x-ray spectroscopy and imagery of solar active regions. Final report

    International Nuclear Information System (INIS)

    Bruner, M.; Brown, W.A.; Haisch, B.M.

    1987-01-01

    A scientific investigation of the physics of the solar atmosphere, which uses the techniques of high resolution soft x-ray spectroscopy and high resolution UV imagery, is described. The experiments were conducted during a series of three sounding rocket flights. All three flights yielded excellent images in the UV range, showing unprecedented spatial resolution. The second flight recorded the x-ray spectrum of a solar flare, and the third that of an active region. A normal incidence multi-layer mirror was used during the third flight to make the first astronomical x-ray observations using this new technique

  6. 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.

  7. Development of a high resolution cylindrical crystal spectrometer for line shape and spectral diagnostics of x-rays emitted from - hot - plasmas. Final report, June 1, 1976-December 31, 1983

    International Nuclear Information System (INIS)

    Kaellne, E.G.

    1984-01-01

    The development, installation and evaluation of a high resolution X-ray spectroscopic diagnostics are reported. The approach has been to optimize spectrometer throughput to enable single shot plasma diagnostics with good time resolution and to ensure sufficient energy resolution to allow line profile analysis. These goals have been achieved using a new X-ray geometry combined with a new position sensitive X-ray detector. These diagnostics have been used at Alcator C to detect X-ray emission of highly ionized impurity elements as well as argon seed elements specially introduced into the plasma for this diagnostic. Temporally resolved ion temperature profiles have been obtained from the recorded X-ray spectra simultaneously with other plasma parameters such as electron temperature, ionization temperature and ionization stage distribution. Radial profiles have also been measured. The developed X-ray diagnostics thus serve as a major multiparameter probe of the central core of the plasma with complementary informtion on radial profiles

  8. New Observations of Soft X-ray (0.5-5 keV) Solar Spectra

    Science.gov (United States)

    Caspi, A.; Woods, T. N.; Mason, J. P.; Jones, A. R.; Warren, H. P.

    2013-12-01

    The solar corona is the brightest source of X-rays in the solar system, and the X-ray emission is highly variable on many time scales. However, the actual solar soft X-ray (SXR) (0.5-5 keV) spectrum is not well known, particularly during solar quiet periods, as, with few exceptions, this energy range has not been systematically studied in many years. Previous observations include high-resolution but very narrow-band spectra from crystal spectrometers (e.g., Yohkoh/BCS), or integrated broadband irradiances from photometers (e.g., GOES/XRS, TIMED/XPS, etc.) that lack detailed spectral information. In recent years, broadband measurements with moderate energy resolution (~0.5-0.7 keV FWHM) were made by SphinX on CORONAS-Photon and SAX on MESSENGER, although they did not extend to energies below ~1 keV. We present observations of solar SXR emission obtained using new instrumentation flown on recent SDO/EVE calibration rocket underflights. The photon-counting spectrometer, a commercial Amptek X123 with a silicon drift detector and an 8 μm Be window, measures the solar disk-integrated SXR emission from ~0.5 to >10 keV with ~0.15 keV FWHM resolution and 1 s cadence. A novel imager, a pinhole X-ray camera using a cooled frame-transfer CCD (15 μm pixel pitch), Ti/Al/C filter, and 5000 line/mm Au transmission grating, images the full Sun in multiple spectral orders from ~0.1 to ~5 nm with ~10 arcsec/pixel and ~0.01 nm/pixel spatial and spectral detector scales, respectively, and 10 s cadence. These instruments are prototypes for future CubeSat missions currently being developed. We present new results of solar observations on 04 October 2013 (NASA sounding rocket 36.290). We compare with previous results from 23 June 2012 (NASA sounding rocket 36.286), during which solar activity was low and no signal was observed above ~4 keV. We compare our spectral and imaging measurements with spectra and broadband irradiances from other instruments, including SDO/EVE, GOES/XRS, TIMED

  9. Broadband X-ray spectra of the ultraluminous x-ray source Holmberg IX X-1 observed with NuSTAR, XMM-Newton, and Suzaku

    DEFF Research Database (Denmark)

    Walton, D. J.; Harrison, F. A.; Grefenstette, B. W.

    2014-01-01

    We present results from the coordinated broadband X-ray observations of the extreme ultraluminous X-ray source Holmberg IX X-1 performed by NuSTAR, XMM-Newton, and Suzaku in late 2012. These observations provide the first high-quality spectra of Holmberg IX X-1 above 10 keV to date, extending the...

  10. HIGH-RESOLUTION X-RAY SPECTROSCOPY REVEALS THE SPECIAL NATURE OF WOLF-RAYET STAR WINDS

    Energy Technology Data Exchange (ETDEWEB)

    Oskinova, L. M.; Hamann, W.-R. [Institute for Physics and Astronomy, University Potsdam, 14476 Potsdam (Germany); Gayley, K. G. [Department of Physics and Astronomy, University of Iowa, Iowa City, IA 52245 (United States); Huenemoerder, D. P. [Massachusetts Institute of Technology, Kavli Institute for Astrophysics and Space Research, 70 Vassar St., Cambridge, MA 02139 (United States); Ignace, R. [Department of Physics and Astronomy, East Tennessee State University, Johnson City, TN 37663 (United States); Pollock, A. M. T., E-mail: lida@astro.physik.uni-potsdam.de [European Space Agency XMM-Newton Science Operations Centre, European Space Astronomy Centre, Apartado 78, Villanueva de la Canada, 28691 Madrid (Spain)

    2012-03-10

    We present the first high-resolution X-ray spectrum of a putatively single Wolf-Rayet (WR) star. 400 ks observations of WR 6 by the XMM-Newton telescope resulted in a superb quality high-resolution X-ray spectrum. Spectral analysis reveals that the X-rays originate far out in the stellar wind, more than 30 stellar radii from the photosphere, and thus outside the wind acceleration zone where the line-driving instability (LDI) could create shocks. The X-ray emitting plasma reaches temperatures up to 50 MK and is embedded within the unshocked, 'cool' stellar wind as revealed by characteristic spectral signatures. We detect a fluorescent Fe line at Almost-Equal-To 6.4 keV. The presence of fluorescence is consistent with a two-component medium, where the cool wind is permeated with the hot X-ray emitting plasma. The wind must have a very porous structure to allow the observed amount of X-rays to escape. We find that neither the LDI nor any alternative binary scenario can explain the data. We suggest a scenario where X-rays are produced when the fast wind rams into slow 'sticky clumps' that resist acceleration. Our new data show that the X-rays in single WR star are generated by some special mechanism different from the one operating in the O-star winds.

  11. Indirect measurements of X-ray spectra

    International Nuclear Information System (INIS)

    Mainardi, R.T.

    2006-01-01

    To the effects of measuring the spectral distribution of the radiation emitted by the x-ray tubes and electron accelerators, numerous procedures that are grouped in two big categories exist at the present time: direct and indirect methods. The first ones use high resolution detectors that should be positioned, together with the appropriate collimator, in the direction of the x ray beam. The user should be an expert in the use and correction of the obtained data by the different effects that affect the detector operation such as efficiency and resolution in terms of the energy of the detected radiation. The indirect procedures, although its are more simple to use, its also require a considerable space along the beam to position the ionization chamber and the necessary absorbents to construct by this way the denominated attenuation curve. We will analyze the operation principle of the indirect methods and a new proposal in which such important novelties are introduced as the beam dispersion to avoid to measure along the main beam and that of determination of the attenuation curve in simultaneous form. By this way, with a single shot of the tube, the attenuation curve is measured, being necessary at most a shot of additional calibration to know the relative response of the detectors used in the experimental array. The physical processes involved in the obtaining of an attenuation curve are very well well-known and this it finishes it can be theoretically calculated if the analytic form of the spectrum is supposed well-known. Finally, we will see a spectra reconstruction example with the Kramers parametric form and comparisons with numeric simulations carried out with broadly validated programs as well as the possibility of the use of solid state dosemeters in the obtention of the attenuation curve. (Author)

  12. X-ray microscopy with high resolution zone plates -- Recent developments

    International Nuclear Information System (INIS)

    Schneider, G.; Wilhein, T.; Niemann, B.; Guttmann, P.

    1995-01-01

    In order to expand the applications of X-ray microscopy, developments in the fields of zone plate technology, specimen preparation and imaging techniques have been made. A new cross-linked polymer chain electron beam resist allows to record zone plate pattern down to 19 nm outermost zone width. High resolution zone plates in germanium with outermost zone widths down to 19 nm have been developed. In addition, phase zone plates in nickel down to 30 nm zone width have been made by electroplating. In order to enhance the image contrast for weak absorbing objects, the phase contrast method for X-ray microscopy was developed and implemented on the Goettingen X-ray microscope at BESSY. The effects of X-ray absorption on the structure of biological specimen limits the maximum applicable radiation dose and therefore the achievable signal to noise ratio for an artifact-free X-ray image. To improve the stability especially of biological specimen, a cryogenic object chamber has been developed and tested. It turns out that at the operating temperature T ≤ 130 K unfixed biological specimen can be exposed to a radiation dose of 10 9 --10 10 Gy without any observable structural changes. A multiple-angle viewing stage allows to take stereoscopic images with the X-ray microscope, giving a 3D-impression of the object

  13. Measurement of spectra for intra-oral X-ray beams using biological materials as attenuator

    International Nuclear Information System (INIS)

    Zenóbio, Madelon A.F.; Nogueira-Tavares, Maria S.; Zenóbio, Elton G.; Squair, Peterson Lima; Santos, Marcus A.P.; Silva, Teógenes A. da

    2011-01-01

    In diagnostic radiology, the radiation interaction probability in matter is a strong function of the X-ray energy. The knowledge of the X-ray energy spectral distribution allows optimizing the radiographic imaging system in order to obtain high quality images with as low as reasonably achievable patient doses. In this study, transmitted X-ray spectra through dentin and enamel that are existing materials in intra-oral radiology were experimentally determined in an X-ray equipment with 40–70 kV variable range. Dentin and enamel samples with 0.4–3.8 and 0.6–2.6 mm thick were used as attenuators. X-ray transmitted spectra were measured with XR-100T model CdTe detector and half-value layers (HVL) were determined. Characteristics of both dentin and enamel transmitted spectra showed that they have differences in the penetration power in matter and in the spectrum distribution. The results will be useful for phantom developments based on dentin and enamel for image quality control in dental radiology. - Highlights: ► The X-ray energy spectral distribution, optimize the radiographic imaging system. Transmitted X-ray spectra through dentin and enamel were experimentally determined. X-ray transmitted spectra were measured (XR-100T model CdTe detector). The transmitted spectra showed differences in the penetration power and spectrum distribution. Dentin and enamel transmitted spectra will be useful for phantom developments.

  14. Energy resolution in X-ray detecting micro-strip gas counters

    CERN Document Server

    Bateman, J E; Derbyshire, G E; Duxbury, D M; Mir, J A; Spill, E J; Stephenson, R

    2002-01-01

    Systematic measurements of the energy resolution available from a Micro-Strip Gas Counter (MSGC) are presented. The effect of factors such as bias potential, gas filling and strip geometry on the energy resolution are examined in detail and related to a simple model. The geometry of the MSGC is adapted to permit 'wall-less' detection of X-rays and this results in useful improvements in the pulse height spectra.

  15. The superconducting high-resolution soft X-ray spectrometer at the advanced biological and environmental X-ray facility

    Energy Technology Data Exchange (ETDEWEB)

    Friedrich, S. [Advanced Detector Group, Lawrence Livermore National Laboratory, 7000 East Avenue, L-188, Livermore, CA 94550 (United States); Advanced Biological and Environmental X-ray Facility, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, MS 6-2100, Berkeley, CA 94720 (United States)], E-mail: Friedrich1@llnl.gov; Drury, O.B. [Advanced Detector Group, Lawrence Livermore National Laboratory, 7000 East Avenue, L-188, Livermore, CA 94550 (United States); Advanced Biological and Environmental X-ray Facility, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, MS 6-2100, Berkeley, CA 94720 (United States); Biophysics Group, University of California, 1 Shields Avenue, EU-III, Davis, CA 95616 (United States); George, S.J. [Advanced Biological and Environmental X-ray Facility, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, MS 6-2100, Berkeley, CA 94720 (United States); Cramer, S.P. [Advanced Biological and Environmental X-ray Facility, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, MS 6-2100, Berkeley, CA 94720 (United States); Biophysics Group, University of California, 1 Shields Avenue, EU-III, Davis, CA 95616 (United States)

    2007-11-11

    We have built a 36-pixel superconducting tunnel junction X-ray spectrometer for chemical analysis of dilute samples in the soft X-ray band. It offers an energy resolution of {approx}10-20 eV FWHM below 1 keV, a solid angle coverage of {approx}10{sup -3}, and can be operated at total rates of up to {approx}10{sup 6} counts/s. Here, we describe the spectrometer performance in speciation measurements by fluorescence-detected X-ray absorption spectroscopy at the Advanced Biological and Environmental X-ray facility at the ALS synchrotron.

  16. A Soft X-ray Spectrometer using a Highly Dispersive Multilayer Grating

    International Nuclear Information System (INIS)

    Warwick, Tony; Padmore, Howard; Voronov, Dmitriy; Yashchuk, Valeriy

    2010-01-01

    There is a need for higher resolution spectrometers as a tool for inelastic x-ray scattering. Currently, resolving power around R = 10,000 is advertised. Measured RIXS spectra are often limited by this instrumental resolution and higher resolution spectrometers using conventional gratings would be prohibitively large. We are engaged in a development program to build blazed multilayer grating structures for diffracting soft x-rays in high order. This leads to spectrometers with dispersion much higher than is possible using metal coated-gratings. The higher dispersion then provides higher resolution and the multilayer gratings are capable of operating away from grazing incidence as required. A spectrometer design is presented with a total length 3.8 m and capable of 10 5 resolving power.

  17. A Soft X-ray Spectrometer using a Highly Dispersive Multilayer Grating

    International Nuclear Information System (INIS)

    Warwick, Tony; Padmore, Howard; Voronov, Dmitriy; Yashchuk, Valeriy

    2010-01-01

    There is a need for higher resolution spectrometers as a tool for inelastic x-ray scattering. Currently, resolving power around R = 10,000 is advertised. Measured RIXS spectra are often limited by this instrumental resolution and higher resolution spectrometers using conventional gratings would be prohibitively large. We are engaged in a development program to build blazed multilayer grating structures for diffracting soft x-rays in high order. This leads to spectrometers with dispersion much higher than is possible using metal coated-gratings. The higher dispersion then provides higher resolution and the multilayer gratings are capable of operating away from grazing incidence as required. A spectrometer design is presented with a total length 3.8m and capable of 10 5 resolving power.

  18. Dynamical and Radiative Properties of X-Ray Pulsar Accretion Columns: Phase-averaged Spectra

    Energy Technology Data Exchange (ETDEWEB)

    West, Brent F. [Department of Electrical and Computer Engineering, United States Naval Academy, Annapolis, MD (United States); Wolfram, Kenneth D. [Naval Research Laboratory (retired), Washington, DC (United States); Becker, Peter A., E-mail: bwest@usna.edu, E-mail: kswolfram@gmail.com, E-mail: pbecker@gmu.edu [Department of Physics and Astronomy, George Mason University, Fairfax, VA (United States)

    2017-02-01

    The availability of the unprecedented spectral resolution provided by modern X-ray observatories is opening up new areas for study involving the coupled formation of the continuum emission and the cyclotron absorption features in accretion-powered X-ray pulsar spectra. Previous research focusing on the dynamics and the associated formation of the observed spectra has largely been confined to the single-fluid model, in which the super-Eddington luminosity inside the column decelerates the flow to rest at the stellar surface, while the dynamical effect of gas pressure is ignored. In a companion paper, we have presented a detailed analysis of the hydrodynamic and thermodynamic structure of the accretion column obtained using a new self-consistent model that includes the effects of both gas and radiation pressures. In this paper, we explore the formation of the associated X-ray spectra using a rigorous photon transport equation that is consistent with the hydrodynamic and thermodynamic structure of the column. We use the new model to obtain phase-averaged spectra and partially occulted spectra for Her X-1, Cen X-3, and LMC X-4. We also use the new model to constrain the emission geometry, and compare the resulting parameters with those obtained using previously published models. Our model sheds new light on the structure of the column, the relationship between the ionized gas and the photons, the competition between diffusive and advective transport, and the magnitude of the energy-averaged cyclotron scattering cross-section.

  19. Mechanical design of a high-resolution x-ray powder diffractometer at the Advanced Photon Source.

    Energy Technology Data Exchange (ETDEWEB)

    Shu, D.; Lee, P.; Preissner, C.; Ramanathan, M.; Beno, M.; VonDreele, R.; Ranay, R.; Ribaud, L.; Kurtz, C.; Jiao, X.; Kline, D.; Jemian, P.; Toby, B.

    2007-01-01

    A novel high-resolution x-ray powder diffractometer has been designed and commissioned at the bending magnet beamline 11-BM at the Advanced Photon Source (APS), Argonne National Laboratory (ANL). This state-of-the-art instrument is designed to meet challenging mechanical and optical specifications for producing high-quality powder diffraction data with high throughput. The 2600 mm (H) X 2100 mm (L) X 1700 mm (W) diffractometer consists of five subassemblies: a customized two-circle goniometer with a 3-D adjustable supporting base; a twelve-channel high-resolution crystal analyzer system with an array of precision x-ray slits; a manipulator system for a twelve scintillator x-ray detectors; a 4-D sample manipulator with cryo-cooling capability; and a robot-based sample exchange automation system. The mechanical design of the diffractometer as well as the test results of its positioning performance are presented in this paper.

  20. Mechanical design of a high-resolution x-ray powder diffractometer at the Advanced Photon Source

    International Nuclear Information System (INIS)

    Shu, D.; Lee, P.; Preissner, C.; Ramanathan, M.; Beno, M.; VonDreele, R.; Ranay, R.; Ribaud, L.; Kurtz, C.; Jiao, X.; Kline, D.; Jemian, P.; Toby, B.

    2007-01-01

    A novel high-resolution x-ray powder diffractometer has been designed and commissioned at the bending magnet beamline 11-BM at the Advanced Photon Source (APS), Argonne National Laboratory (ANL). This state-of-the-art instrument is designed to meet challenging mechanical and optical specifications for producing high-quality powder diffraction data with high throughput. The 2600 mm (H) X 2100 mm (L) X 1700 mm (W) diffractometer consists of five subassemblies: a customized two-circle goniometer with a 3-D adjustable supporting base; a twelve-channel high-resolution crystal analyzer system with an array of precision x-ray slits; a manipulator system for a twelve scintillator x-ray detectors; a 4-D sample manipulator with cryo-cooling capability; and a robot-based sample exchange automation system. The mechanical design of the diffractometer as well as the test results of its positioning performance are presented in this paper.

  1. High-resolution 3D X-ray imaging of intracranial nitinol stents

    International Nuclear Information System (INIS)

    Snoeren, Rudolph M.; With, Peter H.N. de; Soederman, Michael; Kroon, Johannes N.; Roijers, Ruben B.; Babic, Drazenko

    2012-01-01

    To assess an optimized 3D imaging protocol for intracranial nitinol stents in 3D C-arm flat detector imaging. For this purpose, an image quality simulation and an in vitro study was carried out. Nitinol stents of various brands were placed inside an anthropomorphic head phantom, using iodine contrast. Experiments with objects were preceded by image quality and dose simulations. We varied X-ray imaging parameters in a commercially interventional X-ray system to set 3D image quality in the contrast-noise-sharpness space. Beam quality was varied to evaluate contrast of the stents while keeping absorbed dose below recommended values. Two detector formats were used, paired with an appropriate pixel size and X-ray focus size. Zoomed reconstructions were carried out and snapshot images acquired. High contrast spatial resolution was assessed with a CT phantom. We found an optimal protocol for imaging intracranial nitinol stents. Contrast resolution was optimized for nickel-titanium-containing stents. A high spatial resolution larger than 2.1 lp/mm allows struts to be visualized. We obtained images of stents of various brands and a representative set of images is shown. Independent of the make, struts can be imaged with virtually continuous strokes. Measured absorbed doses are shown to be lower than 50 mGy Computed Tomography Dose Index (CTDI). By balancing the modulation transfer of the imaging components and tuning the high-contrast imaging capabilities, we have shown that thin nitinol stent wires can be reconstructed with high contrast-to-noise ratio and good detail, while keeping radiation doses within recommended values. Experimental results compare well with imaging simulations. (orig.)

  2. Hard x-ray monochromator with milli-electron volt bandwidth for high-resolution diffraction studies of diamond crystals

    Energy Technology Data Exchange (ETDEWEB)

    Stoupin, Stanislav; Shvyd' ko, Yuri; Shu Deming; Khachatryan, Ruben; Xiao, Xianghui; DeCarlo, Francesco; Goetze, Kurt; Roberts, Timothy; Roehrig, Christian; Deriy, Alexey [Advanced Photon Source, Argonne National Laboratory, Illinois 60439 (United States)

    2012-02-15

    We report on design and performance of a high-resolution x-ray monochromator with a spectral bandwidth of {Delta}E{sub X}{approx_equal} 1.5 meV, which operates at x-ray energies in the vicinity of the backscattering (Bragg) energy E{sub H} = 13.903 keV of the (008) reflection in diamond. The monochromator is utilized for high-energy-resolution diffraction characterization of diamond crystals as elements of advanced x-ray crystal optics for synchrotrons and x-ray free-electron lasers. The monochromator and the related controls are made portable such that they can be installed and operated at any appropriate synchrotron beamline equipped with a pre-monochromator.

  3. High-speed X-ray topography

    International Nuclear Information System (INIS)

    Eckers, W.; Oppolzer, H.

    1977-01-01

    The investigation of lattice defects in semiconductor crystals by conventional X-ray diffraction topography is very time-consuming. Exposure times can be reduced by using high-intensity X-rays and X-ray image intensifiers. The described system comprises a high-power rotating-anode X-ray tube, a remote-controlled X-ray topography camera, and a television system operating with an X-ray sensing VIDICON. System performance is demonstrated with reference to exploratory examples. The exposure time for photographic plates is reduced to 1/20 and for the X-ray TV system (resolution of the order of 30 μm) to 1/100 relative to that required when using a conventional topography system. (orig.) [de

  4. High-resolution dichroic imaging of magnetic flux distributions in superconductors with scanning x-ray microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Ruoss, Stephen; Stahl, Claudia; Weigand, Markus; Schuetz, Gisela [Max-Planck-Institut fuer Intelligente Systeme, Stuttgart (Germany); Albrecht, Joachim [Research Institute for Innovative Surfaces, FINO, Aalen University (Germany)

    2015-07-01

    The penetration of magnetic flux into the high-temperature superconductor YBCO has been observed using a new high-resolution technique based on X-ray magnetic circular dichroism (XMCD). Superconductors coated with thin soft magnetic layers of CoFeB are observed in a scanning x-ray microscope providing cooling of the sample down to 83 K under the influence of external magnetic fields. Resulting electrical currents create an inhomogeneous magnetic field distribution above the superconductor which leads to a local reorientation of the ferromagnetic layer. X-ray absorption measurements with circular polarized radiation allows the analysis of the magnetic flux distribution in the superconductor via the ferromagnetic layer. In this work we present first images taken at 83K with high spatial resolution in the nanoscale.

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

    International Nuclear Information System (INIS)

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

    2007-01-01

    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 525x525 standard three transistor CMOS active pixel sensor array with more than 75% fill factor and 25x25 μm 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 μm, 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 ∼0.44 μC/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 to structured CsI:Tl can

  6. X-ray Spectroscopy of High-Z Elements on Nike

    Science.gov (United States)

    Aglitskiy, Y.; Weaver, J. L.; Karasik, M.; Serlin, V.; Obenschain, S. P.; Ralchenko, Yu.

    2013-10-01

    Survey X-ray spectrometer covering a spectral range from 0.5 to 19.5 angstroms has been added to the spectroscopic suite of Nike diagnostics. That allows simultaneous observation of both M- and N- spectra of W, Ta and Au with high spectral resolution. Low energy test shots confirmed strong presence of 3-4 transitions of Ni-like W, Ta and Au with X-ray energies as high as 3.5 keV when above mentioned elements were used as the targets. In our continuous effort to support DOE-NNSA's inertial fusion program, the future campaign will cover a wide range of plasma conditions that result in relatively energetic X-ray production. Eventually, absolutely calibrated spectrometers of similar geometry will be fielded at NIF in cooperation with NIF diagnostic group. Work supported by US DOE, Defense Programs.

  7. Changes of soft X-ray emission spectra of oxygen and copper in high Tc superconductors

    International Nuclear Information System (INIS)

    Fukushima, Sei; Gohshi, Yohichi; Kohiki, Shigemi; Saitoh, Naoki

    1989-01-01

    X-ray induced soft X-ray emission spectroscopy is one of the bulk analysis methods used to characterize high-Tc superconductor. In this report, some observations on the changes in O Kα and Cu L spectra of thin layer LnBa 2 Cu 3 O 7-δ (Ln=Er,Gd) samples are presented. From the measurement of O Kα, no discernible difference was found between those of Gd compounds which were composed single phase or not. It may be said that the electronic structure of p state localized on the O is not sensitive to the change of Tc or zero-resistance temperature. From the measurement of Cu L spectra, it was found that Cu Lα of only Gd containing compounds has a low energy shoulder

  8. A high rate, low noise, x-ray silicon strip detector system

    International Nuclear Information System (INIS)

    Ludewigt, B.; Jaklevic, J.; Kipnis, I.; Rossington, C.; Spieler, H.

    1993-11-01

    An x-ray detector system, based on a silicon strip detector wire-bonded to a low noise charge-senstive amplifier integrated circuit, has been developed for synchrotron radiation experiments which require very high count rates and good energy resolution. Noise measurements and x-ray spectra were taken using a 6 mm long, 55 μm pitch strip detector in conjunction with a prototype 16-channel charge-sensitive preamplifier, both fabricated using standard 1.2 μm CMOS technology. The detector system currently achieves an energy resolution of 350 eV FWHM at 5.9 key, 2 μs peaking time, when cooled to -5 degree C

  9. Optimization and energy spectra of x-ray to be used for imaging

    International Nuclear Information System (INIS)

    Nakamori, Nobuyuki; Kanamori, Hitoshi

    1979-01-01

    The relations of the spectra of X-ray used for diagnosis to the absorbed dose of patients and X-ray information are now being investigated by a number of investigators. Here the problems and the trends of the investigations at present are described. Advent of semiconductor detectors has improved the accuracy of measuring X-ray spectra very rapidly. However, since the semiconductor detectors themselves utilize X-ray photon absorption, calibration curves must be prepared for obtaining the true X-ray spectra. Though there are methods of theoretically determining X-ray spectra, no definite theoretical formula is found. Thus, the derivation of an empirical equation based on measured data would be the most fundamental problem. Interactions in an object and the change of X-ray spectra are described on the case of monochromatic and continuous X-ray irradiation. As mentioned above, beam hardening occurs when X-ray enters a matter deep, because the interactions between X-ray and the matter depend upon the photon energy. There are a few methods for correcting the variation of CT (computed tomography) number due to beam hardening. However, prior to this, there are two methods of representing continuous X-ray with single energy, and the unification of the methods or a new way of defining X-ray quality is needed. It has been and is always desirable that monochromatic X-ray source becomes to be useable, and various methods are proposed. (Wakatsuki, Y.)

  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.

    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.

  11. Wavelength dispersive X-ray absorption fine structure imaging by parametric X-ray radiation

    International Nuclear Information System (INIS)

    Inagaki, Manabu; Sakai, Takeshi; Sato, Isamu; Hayakawa, Yasushi; Nogami, Kyoko; Tanaka, Toshinari; Hayakawa, Ken; Nakao, Keisuke

    2008-01-01

    The parametric X-ray radiation (PXR) generator system at Laboratory for Electron Beam Research and Application (LEBRA) in Nihon University is a monochromatic and coherent X-ray source with horizontal wavelength dispersion. The energy definition of the X-rays, which depends on the horizontal size of the incident electron beam on the generator target crystal, has been investigated experimentally by measuring the X-ray absorption near edge structure (XANES) spectra on Cu and CuO associated with conventional X-ray absorption imaging technique. The result demonstrated the controllability of the spectrum resolution of XANES by adjusting of the horizontal electron beam size on the target crystal. The XANES spectra were obtained with energy resolution of several eV at the narrowest case, which is in qualitative agreement with the energy definition of the PXR X-rays evaluated from geometrical consideration. The result also suggested that the wavelength dispersive X-ray absorption fine structure measurement associated with imaging technique is one of the promising applications of PXR. (author)

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

    International Nuclear Information System (INIS)

    Machado, Alessandra C.; Freitas, Renato; Calza, Cristiane F.; Lopes, Ricardo T.; Lima, Inaya; Carvalho, Daniele D.; Gaspar, Maria D.

    2013-01-01

    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)

  13. 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)

  14. The First Non-Dispersive High-Resolution Spectroscopy of an X-ray-bright Galaxy Cluster

    Science.gov (United States)

    Yamaguchi, Hiroya; Hitomi Collaboration

    2018-06-01

    The Hitomi X-ray Observatory was equipped with the Soft X-ray Spectrometer (SXS), an X-ray microcalorimeter that achieved an energy resolution of 5 eV (@0.5-10 keV) for extended objects. This offered an unprecedented benchmark of atomic modeling and database for hot collisional plasmas, revealing both successes and challenges in the current atomic codes that are widely used by the X-ray astronomy community. I will review the Hitomi observations of the brightest part of the Perseus Cluster, whose X-ray spectrum is dominated by thermal emission from the intra-cluster medium (ICM). The SXS successfully measured the turbulent velocities and metal abundances of the ICM, which radically altered our understanding of the dynamics and chemical enrichment in this object. At the same time, the high-resolution X-ray data led to significant improvement in the atomic models, such as AtomDB and SPEX -- I will briefly overview how this improvement was made. Nevertheless, there are still significant discrepancies among the public atomic models, causing systematic uncertainties in measurements of the temperature, abundance, and degree of the resonance scattering. Requirements for future improvements will be summarized in this context.

  15. Theory of X-ray absorption and emission spectra

    International Nuclear Information System (INIS)

    Mukoyama, Takeshi

    2004-01-01

    Theoretical studies on X-ray absorption and emission spectroscopy are discussed. Simple expressions for X-ray emission rate and X-ray absorption cross section are presented in the dipole approximation. Various atomic models to obtain realistic wave functions and theoretical calculations for X-ray absorption cross sections and X-ray emission rates are described. In the case of molecules and solids, molecular orbital methods for electronic structures and molecular wave functions are discussed. The emphasis is on the procedures to obtain the excited-state and continuum wave functions for molecules and to calculate the multi-center dipole matrix elements. The examples of the calculated X-ray absorption and emission spectra are shown and compared with the experimental results

  16. JEM-X: The X-ray monitor aboard INTEGRAL

    DEFF Research Database (Denmark)

    Lund, Niels; Budtz-Jørgensen, Carl; Westergaard, Niels Jørgen Stenfeldt

    2003-01-01

    The JEM-X monitor provides X-ray spectra and imaging with arcminute angular resolution in the 3 to 35 keV band. The good angular resolution and the low energy response of JEM-X plays an important role in the identification of gamma ray sources and in the analysis and scientific interpretation...

  17. LINE FORMATION IN SPECTRA OF X-RAY NOVAE

    OpenAIRE

    Suleimanov, V. F.; Shimansky, V. V.

    2017-01-01

    Results of X-ray Novae (XN) optical spectra computation are presented. The continuum and Balmer line are calculated. The model of XN as a self-irradiated accretion disk is used. Local (for given radius) disk atmospheres as model stellar atmospheres, heated due to external X-ray radiation are treated. Changes of spectra shape and equivalent widths of the Balmer lines depending from the luminosity and some others accretion disk parameters are investigated. The comparison of GRO JO422+32 observe...

  18. High resolution x-ray stereomicroscopy: True three-dimensional imaging of biological samples

    International Nuclear Information System (INIS)

    Loo, B.W.Jr.; Williams, S.; Meizel, S.; Rothman, S.S.; Univ. of California, Berkeley/San Francisco, CA; Univ. of California, San Francisco, CA

    1993-01-01

    X-ray microscopy has the potential to become a powerful tool for the study of biological samples, allowing the imaging of intact cells and subcellular organelles in an aqueous environment at resolutions previously achievable only by electron microscopy. The ability to examine a relatively thick sample raises the issue of superposition of objects from multiple planes within the sample, making difficult the interpretation of conventional, orthogonally projected images. This paper describes early attempts at developing three-dimensional methods for x-ray microimaging: the first to use x-ray optics, and to the authors' knowledge, the first demonstrating sub-visible resolutions and natural contrast. These studies were performed using the scanning transmission x-ray microscope (STXM) at the National Synchrotron Light Source, Brookhaven National Laboratory

  19. Calorimetric low - temperature detectors for high resolution X-ray spectroscopy on stored highly stripped heavy ions

    International Nuclear Information System (INIS)

    Bleile, A.; Egelhof, P.; Kraft, S.; Meier, H.J.; Shrivastava, A.; Weber, M.; McCammon, D.; Stahle, C.K.

    2001-09-01

    The accurate determination of the Lamb shift in heavy hydrogen-like ions provides a sensitive test of quantum electrodynamics in very strong Coulomb fields, not accessible otherwise. For the investigation of the Lyman-α transitions in 208 Pb 81+ or 238 U 91+ with sufficient accuracy, a high resolution calorimetric detector for hard X-rays (E ≤ 100 keV) is presently being developed. The detector modules consist of arrays of silicon thermistors and of X-ray absorbers made of high-Z material to optimize the absorption efficiency. The detectors are housed in a specially designed 3 He/ 4 He dilution refrigerator with a side arm which fits to the internal target geometry of the storage ring ESR at GSI Darmstadt. The detector performance presently achieved is already close to fulfill the demands of the Lamb shift experiment. For a prototype detector pixel with a 0.2 mm 2 x 47 μm Pb absorber an energy resolution of ΔE FWHM = 65 eV is obtained for 60 keV X-rays. (orig.)

  20. Innovative diffraction gratings for high-resolution resonant inelastic soft x-ray scattering spectroscopy

    International Nuclear Information System (INIS)

    Voronov, D.L.; Warwick, T.; Gullikson, E. M.; Salmassi, F.; Padmore, H. A.

    2016-01-01

    High-resolution Resonant Inelastic X-ray Scattering (RIXS) requires diffraction gratings with very exacting characteristics. The gratings should provide both very high dispersion and high efficiency which are conflicting requirements and extremely challenging to satisfy in the soft x-ray region for a traditional grazing incidence geometry. To achieve high dispersion one should increase the groove density of a grating; this however results in a diffraction angle beyond the critical angle range and results in drastic efficiency loss. The problem can be solved by use of multilayer coated blazed gratings (MBG). In this work we have investigated the diffraction characteristics of MBGs via numerical simulations and have developed a procedure for optimization of grating design for a multiplexed high resolution imaging spectrometer for RIXS spectroscopy to be built in sector 6 at the Advanced Light Source (ALS). We found that highest diffraction efficiency can be achieved for gratings optimized for 4"t"h or 5"t"h order operation. Fabrication of such gratings is an extremely challenging technological problem. We present a first experimental prototype of these gratings and report its performance. High order and high line density gratings have the potential to be a revolutionary new optical element that should have great impact in the area of soft x-ray RIXS.

  1. Trial fabrication of a secondary x-ray spectrometer with high energy resolution for use in x-ray resonant inelastic scattering experiments

    International Nuclear Information System (INIS)

    Iwazumi, Toshiaki

    2004-01-01

    An instrument was fabricated for use of x-ray resonant inelastic scattering with high-energy resolution in expectation of finding new physical phenomena in strongly correlated electron systems. In the scattering x-ray spectrometer, an asymmetric Johanson crystal spectrometer, which was deployed in an asymmetric Rowland configuration, was designed, fabricated and assessed. The performance expected theoretically for the Johanson spectrometer was recognized from experiments by use of synchrotron radiation. (Y. Kazumata)

  2. High energy resolution inelastic x-ray scattering at the SRI-CAT

    International Nuclear Information System (INIS)

    Macrander, A.T.

    1996-08-01

    This report is a combination of vugraphs and two papers. The vugraphs give information on the beamline at the APS for IXS and the science addressable by IXS. They also cover the 10 milli-eV resolution spectrometer and the 200 milli-eV resolution spectrometer. The first paper covers the performance of the focusing Ge(444) backscattering analyzers for the inelastic x-ray scattering. The second paper discusses inelastic x-ray scattering from TiC and Ti single crystals

  3. X-ray spectroscopy for high energy-density X pinch density and temperature measurements (invited)

    International Nuclear Information System (INIS)

    Pikuz, S.A.; Shelkovenko, T.A.; Chandler, K.M.; Mitchell, M.D.; Hammer, D.A.; Skobelev, I.Y.; Shlyaptseva, A.S.; Hansen, S.B.

    2004-01-01

    X pinch plasmas produced from fine metal wires can reach near solid densities and temperatures of 1 keV or even more. Plasma conditions change on time scales as short as 5-10 ps as determined using an x-ray streak camera viewing a focusing crystal spectrograph or directly viewing the plasma through multiple filters on a single test. As a result, it is possible to determine plasma conditions from spectra with ∼10 ps time resolution. Experiments and theory are now coming together to give a consistent picture of the dynamics and kinetics of these high energy density plasmas with very high temporal and spatial precision. A set of diagnostic techniques used in experiments for spectrally, temporally, and spatially resolved measurements of X pinch plasmas is described. Results of plasma parameter determination from these measurements are presented. X ray backlighting of one x-pinch by another with ∼30 ps x-ray pulses enables the dynamics and kinetics to be correlated in time

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

    Energy Technology Data Exchange (ETDEWEB)

    Phelan, Kevin, E-mail: kevin.phelan@oeaw.ac.at [Stefan Meyer Institute for Subatomic Physics of The Austrian Academy of Sciences, Boltzmanngasse 3, 1090 Vienna (Austria); Suzuki, Ken; Zmeskal, Johann [Stefan Meyer Institute for Subatomic Physics of The Austrian Academy of Sciences, Boltzmanngasse 3, 1090 Vienna (Austria); Tortorella, Daniele [Payr Engineering GmbH, Wiederschwing 25, A-9564 Patergassen (Austria); Bühler, Matthias; Hertrich, Theo [Low Temperature Solutions UG, Bahnhofstraße 21, D-85737 Ismaning (Germany)

    2017-02-11

    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.

  5. High-resolution X-ray emission spectroscopy with transition-edge sensors: present performance and future potential

    Energy Technology Data Exchange (ETDEWEB)

    Uhlig, J.; Doriese, W. B.; Fowler, J. W.; Swetz, D. S.; Jaye, C.; Fischer, D. A.; Reintsema, C. D.; Bennett, D. A.; Vale, L. R.; Mandal, U.; O' Neil, G. C.; Miaja-Avila, L.; Joe, Y. I.; El Nahhas, A.; Fullagar, W.; Parnefjord Gustafsson, F.; Sundström, V.; Kurunthu, D.; Hilton, G. C.; Schmidt, D. R.; Ullom, J. N.

    2015-04-21

    X-ray emission spectroscopy (XES) is a powerful element-selective tool to analyze the oxidation states of atoms in complex compounds, determine their electronic configuration, and identify unknown compounds in challenging environments. Until now the low efficiency of wavelength-dispersive X-ray spectrometer technology has limited the use of XES, especially in combination with weaker laboratory X-ray sources. More efficient energy-dispersive detectors have either insufficient energy resolution because of the statistical limits described by Fano or too low counting rates to be of practical use. This paper updates an approach to high-resolution X-ray emission spectroscopy that uses a microcalorimeter detector array of superconducting transition-edge sensors (TESs). TES arrays are discussed and compared with conventional methods, and shown under which circumstances they are superior. It is also shown that a TES array can be integrated into a table-top time-resolved X-ray source and a soft X-ray synchrotron beamline to perform emission spectroscopy with good chemical sensitivity over a very wide range of energies.

  6. 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.

  7. X-ray diffractometry with spatial resolution

    International Nuclear Information System (INIS)

    Zeiner, K.

    1981-04-01

    X-ray diffractometry is one of the extensively used methods for investigation of the crystalline structure of materials. Line shape and position of a diffracted line are influenced by grain size, deformation and stress. Spatial resolution of one of these specimen characteristics is usually achieved by point-focused X-ray beams and subsequently analyzing different specimen positions. This work uses the method of image reconstruction from projections for the generation of distribution maps. Additional experimental requirements when using a conventional X-ray goniometer are a specimen scanning unit and a computer. The scanning unit repeatedly performs a number of translation steps followed by a rotation step in a fixed X-ray tube/detector (position sensitive detector) arrangement. At each specimen position a diffraction line is recorded using a line-shaped X-ray beam. This network of diffraction lines (showing line resolution) is mathematically converted to a distribution map of diffraction lines and going thus a point resolution. Specimen areas of up to several cm 2 may be analyzed with a linear resolution of 0.1 to 1 mm. Image reconstruction from projections must be modified for generation of ''function-maps''. This theory is discussed and demonstrated by computer simulations. Diffraction line analysis is done for specimen deformation using a deconvolution procedure. The theoretical considerations are experimentally verified. (author)

  8. High-Resolution and Lightweight X-ray Optics for the X-Ray Surveyor

    Science.gov (United States)

    Zhang, William

    Envisioned in "Enduring Quest, Daring Visions" and under study by NASA as a potential major mission for the 2020s, the X-ray Surveyor mission will likely impose three requirements on its optics: (1) high angular resolution: 0.5 PSF, (2) large effective area: e10,000 cm2 or more, and (3) affordable production cost: $500M. We propose a technology that can meet these requirements by 2020. It will help the X-ray Surveyor secure the endorsement of the coming decadal survey and enable its implementation following WFIRST. The technology comprises four elements: (1) fabrication of lightweight single crystal silicon mirrors, (2) coating these mirrors with iridium to maximize effective area without figure degradation, (3) alignment and bonding of these mirrors to form meta-shells that will be integrated to make a mirror assembly, and (4) systems engineering to ensure that the mirror assembly meet all science performance and spaceflight environmental requirements. This approach grows out of our existing approach based on glass slumping. Using glass slumping technology, we have been able to routinely build and test mirror modules of 10half-power diameter (HPD). While comparable in HPD to XMM-Newtons electroformed nickel mirrors, these mirror modules are 10 times lighter. Likewise, while comparable in weight to Suzakus epoxy-replicated aluminum foil mirrors, these modules have 10 times better HPD. These modules represent the current state of the art of lightweight X-ray optics. Although both successful and mature, the glass slumping technology has reached its limit and cannot achieve sub-arc second HPD. Therefore, we are pursuing the new approach based on polishing single crystal silicon. The new approach will enable the building and testing of mirror modules, called meta-shells, capable of 3HPD by 2018 and 1HPD by 2020, and has the potential to reach diffraction limits ( 0.1) in the 2020s.

  9. X-ray spectra of PG quasars. I. The continuum from X-rays to infrared

    International Nuclear Information System (INIS)

    Elvis, M.; Green, R.F.; Bechtold, J.; Schmidt, M.; Neugebauer, G.; Kitt Peak National Observatory, Tucson, AZ; Steward Observatory, Tucson, AZ; Palomar Observatory, Pasadena, CA)

    1986-01-01

    Einstein IPC X-ray spectra for a sample of eight optically selected quasars from the Palomar Bright Quasar survey are presented. The quasars have a mean power law energy slope which in five individual cases is inconsistent with the value found in hard X-ray selection criterion rather than luminosity, redshift, or U-B color. New IUE and optical continuum spectra and infrared photometry are presented for these quasars. The data are combined into log vf(v) and log v distributions which support the decomposition of the overall quasar spectrum into a power law plus a superposed optical-UV big bump which may be due to an accretion disk. At least six of the quasars have vf(v)s which are roughly constant between their infrared and X-ray power laws, suggesting a strong link between the two regions. 104 references

  10. 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.

  11. 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.

  12. Automated generation and ensemble-learned matching of X-ray absorption spectra

    Science.gov (United States)

    Zheng, Chen; Mathew, Kiran; Chen, Chi; Chen, Yiming; Tang, Hanmei; Dozier, Alan; Kas, Joshua J.; Vila, Fernando D.; Rehr, John J.; Piper, Louis F. J.; Persson, Kristin A.; Ong, Shyue Ping

    2018-03-01

    X-ray absorption spectroscopy (XAS) is a widely used materials characterization technique to determine oxidation states, coordination environment, and other local atomic structure information. Analysis of XAS relies on comparison of measured spectra to reliable reference spectra. However, existing databases of XAS spectra are highly limited both in terms of the number of reference spectra available as well as the breadth of chemistry coverage. In this work, we report the development of XASdb, a large database of computed reference XAS, and an Ensemble-Learned Spectra IdEntification (ELSIE) algorithm for the matching of spectra. XASdb currently hosts more than 800,000 K-edge X-ray absorption near-edge spectra (XANES) for over 40,000 materials from the open-science Materials Project database. We discuss a high-throughput automation framework for FEFF calculations, built on robust, rigorously benchmarked parameters. FEFF is a computer program uses a real-space Green's function approach to calculate X-ray absorption spectra. We will demonstrate that the ELSIE algorithm, which combines 33 weak "learners" comprising a set of preprocessing steps and a similarity metric, can achieve up to 84.2% accuracy in identifying the correct oxidation state and coordination environment of a test set of 19 K-edge XANES spectra encompassing a diverse range of chemistries and crystal structures. The XASdb with the ELSIE algorithm has been integrated into a web application in the Materials Project, providing an important new public resource for the analysis of XAS to all materials researchers. Finally, the ELSIE algorithm itself has been made available as part of veidt, an open source machine-learning library for materials science.

  13. INTEGRAL hard X-ray spectra of the cosmic X-ray background and Galactic ridge emission

    Science.gov (United States)

    Türler, M.; Chernyakova, M.; Courvoisier, T. J.-L.; Lubiński, P.; Neronov, A.; Produit, N.; Walter, R.

    2010-03-01

    Aims: We derive the spectra of the cosmic X-ray background (CXB) and of the Galactic ridge X-ray emission (GRXE) in the ~20-200 keV range from the data of the IBIS instrument aboard the INTEGRAL satellite obtained during the four dedicated Earth-occultation observations in early 2006. Methods: We analyze the modulation of the IBIS/ISGRI detector counts induced by the passage of the Earth through the field of view of the instrument. Unlike previous studies, we do not fix the spectral shape of the various contributions, but model instead their spatial distribution and derive for each of them the expected modulation of the detector counts. The spectra of the diffuse emission components are obtained by fitting the normalizations of the model lightcurves to the observed modulation in different energy bins. Because of degeneracy, we guide the fits with a realistic choice of the input parameters and a constraint for spectral smoothness. Results: The obtained CXB spectrum is consistent with the historic HEAO-1 results and falls slightly below the spectrum derived with Swift/BAT. A 10% higher normalization of the CXB cannot be completely excluded, but it would imply an unrealistically high albedo of the Earth. The derived spectrum of the GRXE confirms the presence of a minimum around 80 keV with improved statistics and yields an estimate of ~0.6 M⊙ for the average mass of white dwarfs in the Galaxy. The analysis also provides updated normalizations for the spectra of the Earth's albedo and the cosmic-ray induced atmospheric emission. Conclusions: This study demonstrates the potential of INTEGRAL Earth-occultation observations to derive the hard X-ray spectra of three fundamental components: the CXB, the GRXE and the Earth emission. Further observations would be extremely valuable to confirm our results with improved statistics.

  14. Development and features of an X-ray detector with high spatial resolution

    International Nuclear Information System (INIS)

    Hartmann, H.

    1979-09-01

    A laboratory model of an X-ray detector with high spatial resolution was developed and constructed. It has no spectral resolution, but a local resolution of 20 μm which is about ten times as high as that of position-sensitive proportional counters and satisfies the requirements of the very best Wolter telescopes with regard to spatial resolution. The detector will be used for laboratory tests of the 80 cm Wolter telescope which is being developed for Spacelab flights. The theory of the wire grid detector and the physics of the photoelectric effect has been developed, and model calculations and numerical calculations have been carried out. (orig./WB) [de

  15. A high resolution, high counting rate bidimensional, MWPC imaging detector for small angle X-ray diffraction studies

    International Nuclear Information System (INIS)

    Bateman, J.E.; Connolly, J.F.; Sawyer, E.C.; Stephenson, R.

    1981-07-01

    The performance is reported of a 200 mm x 200 mm X-ray imaging MWPC aimed at applications in small angle X-ray diffraction and scattering. With quantum energies of approximately 8 keV high spatial resolution (+- 0.5 mm x +- 0.14 mm) with a capability for data taking at >approximately 350 kHz is reported. The detection efficiency is approximately 75% and the detector operates as a sealed unit with a long lifetime. (author)

  16. High-resolution x-ray computed tomography to understand ruminant phylogeny

    Science.gov (United States)

    Costeur, Loic; Schulz, Georg; Müller, Bert

    2014-09-01

    High-resolution X-ray computed tomography has become a vital technique to study fossils down to the true micrometer level. Paleontological research requires the non-destructive analysis of internal structures of fossil specimens. We show how X-ray computed tomography enables us to visualize the inner ear of extinct and extant ruminants without skull destruction. The inner ear, a sensory organ for hearing and balance has a rather complex three-dimensional morphology and thus provides relevant phylogenetical information what has been to date essentially shown in primates. We made visible the inner ears of a set of living and fossil ruminants using the phoenix x-ray nanotom®m (GE Sensing and Inspection Technologies GmbH). Because of the high absorbing objects a tungsten target was used and the experiments were performed with maximum accelerating voltage of 180 kV and a beam current of 30 μA. Possible stem ruminants of the living families are known in the fossil record but extreme morphological convergences in external structures such as teeth is a strong limitation to our understanding of the evolutionary history of this economically important group of animals. We thus investigate the inner ear to assess its phylogenetical potential for ruminants and our first results show strong family-level morphological differences.

  17. On the origin of X-ray spectra in luminous blazars

    International Nuclear Information System (INIS)

    Sikora, Marek; Janiak, Mateusz; Moderski, Rafał; Nalewajko, Krzysztof; Madejski, Greg M.

    2013-01-01

    Gamma-ray luminosities of some quasar-associated blazars imply jet powers reaching values comparable to the accretion power even if assuming very strong Doppler boosting and very high efficiency of gamma-ray production. With much lower radiative efficiencies of protons than of electrons, and the recent reports of very strong coupling of electrons with shock-heated protons indicated by particle-in-cell simulations, the leptonic models seem to be strongly favored over the hadronic ones. However, the electron-proton coupling combined with the external-radiation-Compton (ERC) models of gamma-ray production in leptonic models predict extremely hard X-ray spectra, with energy indices α x ∼ 0. This is inconsistent with the observed 2-10 keV slopes of blazars, which cluster around α x ∼ 0.6. This problem can be resolved by assuming that electrons can be efficiently cooled down radiatively to non-relativistic energies, or that blazar spectra are entirely dominated by the synchrotron self-Compton (SSC) component up to at least 10 keV. Here, we show that the required cooling can be sufficiently efficient only at distances r < 0.03 pc. SSC spectra, on the other hand, can be produced roughly co-spatially with the observed synchrotron and ERC components, which are most likely located roughly at a parsec scale. We show that the dominant SSC component can also be produced much further than the dominant synchrotron and ERC components, at distances of ≳ 10 pc. Hence, depending on the spatial distribution of the energy dissipation along the jet, one may expect to see γ-ray/optical events with either correlated or uncorrelated X-rays. In all cases the number of e + e – pairs per proton is predicted to be very low. The direct verification of the proposed SSC scenario, and particularly the question of the co-spatiality of the SSC component with other spectral components, requires sensitive observations in the hard X-ray band. This is now possible with the deployment of the Nu

  18. 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.

  19. Radiation detectors of PIN type for X-rays

    International Nuclear Information System (INIS)

    Ramirez-Jimenez, F.J.

    2003-01-01

    In this laboratory session, tree experiments are proposed: the measurement of X-ray energy spectra from radioactive sources with a high resolution cooled Si-Li detector, with a room temperature PIN diode and the measurement of the response of a PIN diode to the intensity of X-rays of radio-diagnostic units. The spectra obtained with the Si-Li detector help to understand the energy distribution of X-rays and are used as a reference to compare the results obtained with the PIN diode. Measurements in medical X-ray machines are proposed. Low cost, simple electronic instruments and systems are used as tools to make measurements in X-ray units used in radio-diagnostic

  20. 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.

  1. 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.

  2. 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.

  3. Structure of high-resolution NMR spectra

    CERN Document Server

    Corio, PL

    2012-01-01

    Structure of High-Resolution NMR Spectra provides the principles, theories, and mathematical and physical concepts of high-resolution nuclear magnetic resonance spectra.The book presents the elementary theory of magnetic resonance; the quantum mechanical theory of angular momentum; the general theory of steady state spectra; and multiple quantum transitions, double resonance and spin echo experiments.Physicists, chemists, and researchers will find the book a valuable reference text.

  4. 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

  5. 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.

  6. Many-body effects on the x-ray spectra of metals

    International Nuclear Information System (INIS)

    Satpathy, S.S.

    1982-01-01

    The effects of band structure, of a solid surface, of temperature, and of disorder on the many-electron x-ray spectra of metals are evaluated in a change-of-mean-field approximation using a one-dimensional nearest-neighbor tight-binding model of a metal. The x-ray spectral shapes are determined by both the band structure and the final-state interactions. The effect of the band being non-free-electron-like is not felt at the x-ray threshold, but away from it such effects are noticeable. When the core hole is created at the surface, the spectra at the edge exhibit a Nozieres-de Dominicis-type singularity with the appropriate surface phase-shifts. At energies away from the edge, the one-particle effects are prominent with the x-ray emission and absorption spectra closely reflecting the local one-electron density of states. The recoil spectrum of a Fermi sea at a non-zero temperature has less asymmetry than the zero-temperature case. It was found that at ordinary temperatures the reduction of the asymmetry due to the thermal distribution of one-electron states is not very significant. Finally, using a one-dimensional Anderson model, the effect of lattice disorder on the x-ray absorption spectra is studied for the first time. There are two effects: (1) the strong infrared divergence peak is gradually quenched as disorder is increased, and (2) the threshold is broadened because the threshold energies for absorption at different sites in the crystal depend on the varying local lattice environment. It is proposed that the x-ray spectra may be useful as a tool for studying the degree of electron localization in disordered many-electron systems

  7. 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.

  8. High Resolution, Non-Dispersive X-Ray Calorimeter Spectrometers on EBITs and Orbiting Observatories

    Science.gov (United States)

    Porter, Frederick S.

    2010-01-01

    X-ray spectroscopy is the primary tool for performing atomic physics with Electron beam ion trap (EBITs). X-ray instruments have generally fallen into two general categories, 1) dispersive instruments with very high spectral resolving powers but limited spectral range, limited count rates, and require an entrance slit, generally, for EBITs, defined by the electron beam itself, and 2) non-dispersive solid-state detectors with much lower spectral resolving powers but that have a broad dynamic range, high count rate ability and do not require a slit. Both of these approaches have compromises that limit the type and efficiency of measurements that can be performed. In 1984 NASA initiated a program to produce a non-dispersive instrument with high spectral resolving power for x-ray astrophysics based on the cryogenic x-ray calorimeter. This program produced the XRS non-dispersive spectrometers on the Astro-E, Astro-E2 (Suzaku) orbiting observatories, the SXS instrument on the Astro-H observatory, and the planned XMS instrument on the International X-ray Observatory. Complimenting these spaceflight programs, a permanent high-resolution x-ray calorimeter spectrometer, the XRS/EBIT, was installed on the LLNL EBIT in 2000. This unique instrument was upgraded to a spectral resolving power of 1000 at 6 keV in 2003 and replaced by a nearly autonomous production-class spectrometer, the EBIT Calorimeter Spectrometer (ECS), in 2007. The ECS spectrometer has a simultaneous bandpass from 0.07 to over 100 keV with a spectral resolving power of 1300 at 6 keV with unit quantum efficiency, and 1900 at 60 keV with a quantum efficiency of 30%. X-ray calorimeters are event based, single photon spectrometers with event time tagging to better than 10 us. We are currently developing a follow-on instrument based on a newer generation of x-ray calorimeters with a spectral resolving power of 3000 at 6 keV, and improved timing and measurement cadence. The unique capabilities of the x-ray

  9. Efficient high-resolution X-ray emission spectrometry using synchrotron radiation

    International Nuclear Information System (INIS)

    Unterumsberger, Rainer

    2015-01-01

    5.10 15 atoms/cm 2 , respectively). With the spectrometer extended by the refocusing, XES at different titanium oxides could be performed. Using the high-resolution XES, the chemical species of the different titanium oxides could be identified. In addition to the chemical speciation, it is now possible to do Resonance Inelastic X-Ray Scattering (RIXS). With this method, information about the occupied and unoccupied electronic states of the valence electrons can be revealed. For a quantitative analysis of the titanium L-fluorescence lines, the WDS had to be calibrated. For this purpose, the response behavior of the spectrometer was experimental determined using direct undulator radiation. By means of a model function for the response behavior, the response functions could be modeled and parameterized for the whole covered energy range. The response functions lead to a reliable deconvolution of the emission spectra and thereby allow an accurate determination of the fluorescence intensities. In this work, the relative uncertainties of the intensities are estimated with about 15 %. The transition probabilities of the titanium L3-fluorescence lines were determined as a function of the chemical state. For metallic titanium, the transition probability of the titanium Ll-fluorescence line amounts to 0.59(6) and decreases with increasing oxidation state of the titanium. For titanium dioxide, the transition probability of the titanium Ll-fluorescence line only amounts to 0.46(7).

  10. Unambiguous determination of H-atom positions: comparing results from neutron and high-resolution X-ray crystallography.

    Science.gov (United States)

    Gardberg, Anna S; Del Castillo, Alexis Rae; Weiss, Kevin L; Meilleur, Flora; Blakeley, Matthew P; Myles, Dean A A

    2010-05-01

    The locations of H atoms in biological structures can be difficult to determine using X-ray diffraction methods. Neutron diffraction offers a relatively greater scattering magnitude from H and D atoms. Here, 1.65 A resolution neutron diffraction studies of fully perdeuterated and selectively CH(3)-protonated perdeuterated crystals of Pyrococcus furiosus rubredoxin (D-rubredoxin and HD-rubredoxin, respectively) at room temperature (RT) are described, as well as 1.1 A resolution X-ray diffraction studies of the same protein at both RT and 100 K. The two techniques are quantitatively compared in terms of their power to directly provide atomic positions for D atoms and analyze the role played by atomic thermal motion by computing the sigma level at the D-atom coordinate in simulated-annealing composite D-OMIT maps. It is shown that 1.65 A resolution RT neutron data for perdeuterated rubredoxin are approximately 8 times more likely overall to provide high-confidence positions for D atoms than 1.1 A resolution X-ray data at 100 K or RT. At or above the 1.0sigma level, the joint X-ray/neutron (XN) structures define 342/378 (90%) and 291/365 (80%) of the D-atom positions for D-rubredoxin and HD-rubredoxin, respectively. The X-ray-only 1.1 A resolution 100 K structures determine only 19/388 (5%) and 8/388 (2%) of the D-atom positions above the 1.0sigma level for D-rubredoxin and HD-rubredoxin, respectively. Furthermore, the improved model obtained from joint XN refinement yielded improved electron-density maps, permitting the location of more D atoms than electron-density maps from models refined against X-ray data only.

  11. Electron-electron correlation, resonant photoemission and X-ray emission spectra

    International Nuclear Information System (INIS)

    Parlebas, J.C.; Kotani, Akio; Tanaka, Satoshi.

    1991-01-01

    In this short review paper we essentially focus on the high energy spectroscopies which involve second order quantum processes, i.e., resonance photoemission, Auger and X-ray emission spectroscopies, denoted respectively by RXPS, AES and XES. First, we summarize the main 3p-RXPS and AES results obtained in Cu and Ni metals; especially we recall that the satellite near the 3p-threshold in the spectra, which arises from a d-hole pair bound state, needs a careful treatment of the electron-electron correlation. Then we analyze the RXPS spectra in a few Ce compounds (CeO 2 , Ce 2 O 3 and CeF 3 ) involving 3d or 4d core levels and we interpret the spectra consistently with the other spectroscopies, such as core XPS and XAS which are first order quantum processes. Finally within the same one-impurity model and basically with the same sets of parameters, we review a theory for the Ce 5p→3d XES, as well as for the corresponding RXES, where (1) the incident X-ray is tuned to resonate with the 3d→4f transition and (2) the X-ray emission due to the 5p→3d transition is actually observed. The paper ends with a general discussion. (author) 77 refs

  12. Analysis of X-Ray (L) spectra of heavy elements

    International Nuclear Information System (INIS)

    Souza Coelho, L.F. de.

    1976-08-01

    The general problem of obtaining and analysing spectra is presented, with emphasis in the comparison of methods for the analysis of gamma rays and X rays. The method proposed to obtain a standard and later the intensities of lines of an X-ray (L) spectrum is discussed. The good eesults obtained by the program RAIOXL, when simulated spectra are used, and by the program RAIXL1, when doublets are decomposed, are shown. In annex A, the listings of the programs used are presented, and in annex B a review is made of the analytical formulae used for adjustment of the pulses. (I.C.R.) [pt

  13. Design and image-quality performance of high resolution CMOS-based X-ray imaging detectors for digital mammography

    Science.gov (United States)

    Cha, B. K.; Kim, J. Y.; Kim, Y. J.; Yun, S.; Cho, G.; Kim, H. K.; Seo, C.-W.; Jeon, S.; Huh, Y.

    2012-04-01

    In digital X-ray imaging systems, X-ray imaging detectors based on scintillating screens with electronic devices such as charge-coupled devices (CCDs), thin-film transistors (TFT), complementary metal oxide semiconductor (CMOS) flat panel imagers have been introduced for general radiography, dental, mammography and non-destructive testing (NDT) applications. Recently, a large-area CMOS active-pixel sensor (APS) in combination with scintillation films has been widely used in a variety of digital X-ray imaging applications. We employed a scintillator-based CMOS APS image sensor for high-resolution mammography. In this work, both powder-type Gd2O2S:Tb and a columnar structured CsI:Tl scintillation screens with various thicknesses were fabricated and used as materials to convert X-ray into visible light. These scintillating screens were directly coupled to a CMOS flat panel imager with a 25 × 50 mm2 active area and a 48 μm pixel pitch for high spatial resolution acquisition. We used a W/Al mammographic X-ray source with a 30 kVp energy condition. The imaging characterization of the X-ray detector was measured and analyzed in terms of linearity in incident X-ray dose, modulation transfer function (MTF), noise-power spectrum (NPS) and detective quantum efficiency (DQE).

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

    International Nuclear Information System (INIS)

    Jakubek, Jan; Granja, Carlos; Dammer, Jiri; Hanus, Robert; Holy, Tomas; Pospisil, Stanislav; Tykva, Richard; Uher, Josef; Vykydal, Zdenek

    2007-01-01

    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

  15. High resolution hard X-ray photoemission using synchrotron radiation as an essential tool for characterization of thin solid films

    International Nuclear Information System (INIS)

    Kim, J.J.; Ikenaga, E.; Kobata, M.; Takeuchi, A.; Awaji, M.; Makino, H.; Chen, P.P.; Yamamoto, A.; Matsuoka, T.; Miwa, D.; Nishino, Y.; Yamamoto, T.; Yao, T.; Kobayashi, K.

    2006-01-01

    Recently, we have shown that hard X-ray photoemission spectroscopy using undulator X-rays at SPring-8 is quite feasible with both high resolution and high throughput. Here we report an application of hard X-ray photoemission spectroscopy to the characterization of electronic and chemical states of thin solid films, for which conventional PES is not applicable. As a typical example, we focus on the problem of the scatter in the reported band-gap values for InN. We show that oxygen incorporation into the InN film strongly modifies the valence and plays a crucial role in the band gap problem. The present results demonstrate the powerful applicability of high resolution photoemission spectroscopy with hard X-rays from a synchrotron source

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

    International Nuclear Information System (INIS)

    Ghazi, M.E.

    2002-01-01

    Many important properties of transition metal oxides such as, copper oxide high-temperature superconductivity and colossal magnetoresistance (CMR) in manganites are due to strong electron-electron interactions, and hence these systems are called highly correlated systems. These materials are characterised by the coexistence of different kinds of order, including charge, orbital, and magnetic moment. This thesis contains high-resolution X-ray scattering studies of charge ordering in such systems namely the high-T C copper oxides isostructural system, La 2-x Sr x NiO 4 with various Sr concentrations (x = 0.33 - 0.2), and the CMR manganite system, Nd 1/2 Sr 1/2 MnO 3 . It also includes a review of charge ordering in a large variety of transition metal oxides, such as ferrates, vanadates, cobaltates, nickelates, manganites, and cuprates systems, which have been reported to date in the scientific literature. Using high-resolution synchrotron X-ray scattering, it has been demonstrated that the charge stripes exist in a series of single crystals of La 2-x Sr x NiO 4 with Sr concentrations (x = 0.33 - 0.2) at low temperatures. Satellite reflections due to the charge ordering were found with the wavevector (2ε, 0, 1) below the charge ordering transition temperature, T CO , where 2ε is the amount of separation from the corresponding Bragg peak. The charge stripes are shown to be 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

  17. Development of Small-Pixel CZT Detectors for Future High-Resolution Hard X-ray Missions

    Science.gov (United States)

    Beilicke, Matthias

    Owing to recent breakthroughs in grazing incidence mirror technology, next-generation hard X-ray telescopes will achieve angular resolutions of between 5 and 10 arc seconds - about an order of magnitude better than that of the NuSTAR hard X-ray telescope. As a consequence, the next generation of hard X-ray telescopes will require pixelated hard X- ray detectors with pixels on a grid with a lattice constant of between 120 and 240 um. Additional detector requirements include a low energy threshold of less than 5 keV and an energy resolution of less than 1 keV. The science drivers for a high angular-resolution hard X-ray mission include studies and measurements of black hole spins, the cosmic evolution of super-massive black holes, AGN feedback, and the behavior of matter at very high densities. We propose a R&D research program to develop, optimize and study the performance of 100-200 um pixel pitch CdTe and Cadmium Zinc Telluride (CZT) detectors of 1-2 mm thickness. Our program aims at a comparison of the performance achieved with CdTe and CZT detectors, and the optimization of the pixel, steering grid, and guard ring anode patterns. Although these studies will use existing ASICs (Application Specific Integrated Circuits), our program also includes modest funds for the development of an ultra-low noise ASIC with a 2-D grid of readout pads that can be directly bonded to the 100-200 um pixel pitch CdTe and CZT detectors. The team includes the Washington University group (Prof. M. Beilicke and Co-I Prof. H.S.W. Krawczynski et al.), and co-investigator G. De Geronimo at Brookhaven National Laboratory (BNL). The Washington University group has a 10 year track record of innovative CZT detector R&D sponsored by the NASA Astronomy and Physics Research and Analysis (APRA) program. The accomplishments to date include the development of CZT detectors with pixel pitches between 350 um and 2.5 mm for the ProtoExist, EXIST, and X-Calibur hard X-ray missions with some of the best

  18. X-ray spectroscopic study of high-temperature plasmas by curved crystal spectrometer

    International Nuclear Information System (INIS)

    Morita, Shigeru.

    1983-07-01

    Extensive studies have been carried out on the structure of X-ray spectra from the highly stripped ions of first transition elements and their behavior in high temperature plasma, using a high resolution crystal spectrometer. Calculation was made on the design and the use of a curved crystal spectrometer for plasma diagnostics. A Johann type crystal spectrometer for measuring X-ray lines was constructed on the basis of the calculation. The characteristics of curved crystals of LiF, Ge and quartz used for the measurement of Kα lines from first transition elements were investigated. Vacuum sparks have been formed for producing high temperature plasma which emits X-ray lines from highly stripped ions. Two different structures of vacuum spark plasma were shown, that is, thermalized point plasma and extended plasma associated with non-thermal electrons. The X-ray lines from the extended plasma, those associated with the K shell from the point plasma and the Kα lines of Ti through Zn from the point plasma have been observed. (Kako, I.)

  19. High resolution x-ray microscope

    OpenAIRE

    Gary, C. K.; Park, H.; Lombardo, L. W.; Piestrup, M. A.; Cremer, J. T.; Pantell, R. H.; Dudchik, Y. I.

    2007-01-01

    The authors present x-ray images of grid meshes and biological material obtained using a microspot x-ray tube with a multilayer optic and a 92-element parabolic compound refractive lens CRL made of a plastic containing only hydrogen and carbon. Images obtained using this apparatus are compared with those using an area source with a spherical lens and a spherical lens with multilayer condenser. The authors found the best image quality using the multilayer condenser with a parabolic lens, com...

  20. Energy resolution and throughput of a new real time digital pulse processing system for x-ray and gamma ray semiconductor detectors

    International Nuclear Information System (INIS)

    Abbene, L; Gerardi, G; Raso, G; Brai, M; Principato, F; Basile, S

    2013-01-01

    New generation spectroscopy systems have advanced towards digital pulse processing (DPP) approaches. DPP systems, based on direct digitizing and processing of detector signals, have recently been favoured over analog pulse processing electronics, ensuring higher flexibility, stability, lower dead time, higher throughput and better spectroscopic performance. In this work, we present the performance of a new real time DPP system for X-ray and gamma ray semiconductor detectors. The system is based on a commercial digitizer equipped with a custom DPP firmware, developed by our group, for on-line pulse shape and height analysis. X-ray and gamma ray spectra measurements with cadmium telluride (CdTe) and germanium (Ge) detectors, coupled to resistive-feedback preamplifiers, highlight the excellent performance of the system both at low and high rate environments (up to 800 kcps). A comparison with a conventional analog electronics showed the better high-rate capabilities of the digital approach, in terms of energy resolution and throughput. These results make the proposed DPP system a very attractive tool for both laboratory research and for the development of advanced detection systems for high-rate-resolution spectroscopic imaging, recently proposed in diagnostic medicine, industrial imaging and security screening

  1. 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.)

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

    International Nuclear Information System (INIS)

    Rettenbacher, Thomas; Ennemoser, Sybille; Weirich, Harald; Ulmer, Hanno; Hartig, Frank; Klotz, Werner; Herold, Manfred

    2008-01-01

    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.)

  3. A mirror for lab-based quasi-monochromatic parallel x-rays.

    Science.gov (United States)

    Nguyen, Thanhhai; Lu, Xun; Lee, Chang Jun; Jung, Jin-Ho; Jin, Gye-Hwan; Kim, Sung Youb; Jeon, Insu

    2014-09-01

    A multilayered parabolic mirror with six W/Al bilayers was designed and fabricated to generate monochromatic parallel x-rays using a lab-based x-ray source. Using this mirror, curved bright bands were obtained in x-ray images as reflected x-rays. The parallelism of the reflected x-rays was investigated using the shape of the bands. The intensity and monochromatic characteristics of the reflected x-rays were evaluated through measurements of the x-ray spectra in the band. High intensity, nearly monochromatic, and parallel x-rays, which can be used for high resolution x-ray microscopes and local radiation therapy systems, were obtained.

  4. 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.

  5. Finite temperature effects on the X-ray absorption spectra of energy related materials

    Science.gov (United States)

    Pascal, Tod; Prendergast, David

    2014-03-01

    We elucidate the role of room-temperature-induced instantaneous structural distortions in the Li K-edge X-ray absorption spectra (XAS) of crystalline LiF, Li2SO4, Li2O, Li3N and Li2CO3 using high resolution X-ray Raman spectroscopy (XRS) measurements and first-principles density functional theory calculations within the eXcited electron and Core Hole (XCH) approach. Based on thermodynamic sampling via ab-initio molecular dynamics (MD) simulations, we find calculated XAS in much better agreement with experiment than those computed using the rigid crystal structure alone. We show that local instantaneous distortion of the atomic lattice perturbs the symmetry of the Li 1 s core-excited-state electronic structure, broadening spectral line-shapes and, in some cases, producing additional spectral features. This work was conducted within the Batteries for Advanced Transportation Technologies (BATT) Program, supported by the U.S. Department of Energy Vehicle Technologies Program under Contract No. DE-AC02-05CH11231.

  6. Envelope method for background elimination from X-ray fluorescence spectra

    International Nuclear Information System (INIS)

    Monakhov, V.V.; Naumenko, P.A.; Chashinskaya, O.A.

    2006-01-01

    The influence of the background noise caused by Bremsstrahlung on the accuracy of the envelope method at x-ray fluorescence spectra processing is studied. This is carried out by the example of model spectra at different forms of Bremsstrahlung noise as well as at the presence of background noise in spectra. The interpolation by parabolic splines is used for the estimation of the error of the envelope method for the elimination of continuos background noise. It is found out that the error of the proposed method constitutes decimal parts of percent. It is shown that the envelope method is the effective technique for the elimination of the continuous Bremsstrahlung from x-ray fluorescence spectra of the first order [ru

  7. The Soft X-ray Spectrophotometer SphinX for the CORONAS-Photon Mission

    Science.gov (United States)

    Sylwester, Janusz; Kowalinski, Miroslaw; Szymon, Gburek; Bakala, Jaroslaw; Kuzin, Sergey; Kotov, Yury; Farnik, Frantisek; Reale, Fabio

    The purpose, construction details and calibration results of the new design, Polish-led solar X-ray spectrophotometer SphinX will be presented. The instrument constitutes a part of the Russian TESIS X-ray and EUV complex aboard the forthcoming CORONAS-Photon solar mission to be launched later in 2008. SphinX uses Si-PIN detectors for high time resolution (down to 0.01 s) measurements of solar spectra in the energy range between 0.5 keV and 15 keV. The spectral resolution allows separating 256 individual energy channels in this range with particular groups of lines clearly distinguishable. Unprecedented accuracy of the instrument calibration at the XACT (Palermo) and BESSY (Berlin) synchrotron will allow for establishing the solar soft X-ray photometric reference system. The cross-comparison between SphinX and the other instruments presently in orbit like XRT on Hinode, RHESSI and GOES X-ray monitor, will allow for a precise determination of the coronal emission measure and temperature during both very low and very high activity periods. Examples of the detectors' ground calibration results as well as the calculated synthetic spectra will be presented. The operation of the instrument while in orbit will be discussed allowing for suggestions from other groups to be still included in mission planning.

  8. Upgrades of imaging x-ray crystal spectrometers for high-resolution and high-temperature plasma diagnostics on EAST

    Energy Technology Data Exchange (ETDEWEB)

    Lyu, B., E-mail: blu@ipp.ac.cn; Wang, F. D.; Fu, J.; Li, Y. Y. [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, Anhui 230031 (China); Pan, X. Y.; Chen, J.; Wan, B. N. [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, Anhui 230031 (China); School of Nuclear Science and Technology, University of Science and Technology of China, Hefei, Anhui 230026 (China); Bitter, M.; Hill, K. W.; Delgado-Aparicio, L. F.; Pablant, N. [Princeton Plasma Physics Laboratory, P.O. Box 451, Princeton, New Jersey 08543-0451 (United States); Lee, S. G. [National Fusion Research Institute, 52 Eoeun-Dong, Yusung-Gu, Daejeon 305-333 (Korea, Republic of); Shi, Y. J. [School of Nuclear Science and Technology, University of Science and Technology of China, Hefei, Anhui 230026 (China); WCI for Fusion Theory, National Fusion Research Institute, 52 Eoeun-Dong, Yusung-Gu, Daejeon 305-333 (Korea, Republic of); Ye, M. Y. [School of Nuclear Science and Technology, University of Science and Technology of China, Hefei, Anhui 230026 (China)

    2014-11-15

    Upgrade of the imaging X-ray crystal spectrometers continues in order to fulfill the high-performance diagnostics requirements on EAST. For the tangential spectrometer, a new large pixelated two-dimensional detector was deployed on tokamaks for time-resolved X-ray imaging. This vacuum-compatible detector has an area of 83.8 × 325.3 mm{sup 2}, a framing rate over 150 Hz, and water-cooling capability for long-pulse discharges. To effectively extend the temperature limit, a double-crystal assembly was designed to replace the previous single crystals for He-like argon line measurement. The tangential spectrometer employed two crystal slices attached to a common substrate and part of He- and H-like Ar spectra could be recorded on the same detector when crystals were chosen to have similar Bragg angles. This setup cannot only extend the measurable Te up to 10 keV in the core region, but also extend the spatial coverage since He-like argon ions will be present in the outer plasma region. Similarly, crystal slices for He-like iron and argon spectra were adopted on the poloidal spectrometer. Wavelength calibration for absolute rotation velocity measurement will be studied using cadmium characteristic L-shell X-ray lines excited by plasma radiation. A Cd foil is placed before the crystal and can be inserted and retracted for in situ wavelength calibration. The Geant4 code was used to estimate X-ray fluorescence yield and optimize the thickness of the foil.

  9. High-resolution multi-MeV x-ray radiography using relativistic laser-solid interaction

    International Nuclear Information System (INIS)

    Courtois, C.; Compant La Fontaine, A.; Barbotin, M.; Bazzoli, S.; Brebion, D.; Bourgade, J. L.; Gazave, J.; Lagrange, J. M.; Landoas, O.; Le Dain, L.; Lefebvre, E.; Pichoff, N.; Edwards, R.; Aedy, C.; Biddle, L.; Drew, D.; Gardner, M.; Ramsay, M.; Simons, A.; Sircombe, N.

    2011-01-01

    When high intensity (≥10 19 W cm -2 ) laser light interacts with matter, multi-MeV electrons are produced. These electrons can be utilized to generate a MeV bremsstrahlung x-ray emission spectrum as they propagate into a high-Z solid target positioned behind the interaction area. The short duration ( 2 ) object is then performed with few hundred microns spatial resolution.

  10. FRONT-END ASIC FOR HIGH RESOLUTION X-RAY SPECTROMETERS

    International Nuclear Information System (INIS)

    DE GERONIMO, G.; CHEN, W.; FRIED, J.; LI, Z.; PINELLI, D.A.; REHAK, P.; VERNON, E.; GASKIN, J.A.; RAMSEY, B.D.; ANELLI, G.

    2007-01-01

    We present an application specific integrated circuit (ASIC) for high-resolution x-ray spectrometers. The ASIC is designed to read out signals from a pixelated silicon drift detector (SDD). Each hexagonal pixel has an area of 15 mmz and an anode capacitance of less than 100 fF. There is no integrated Field Effect transistor (FET) in the pixel, rather, the readout is done by wirebonding the anodes to the inputs of the ASIC. The ASIC provides 14 channels of low-noise charge amplification, high-order shaping with baseline stabilization, and peak detection with analog memory. The readout is sparse and based on low voltage differential signaling. An interposer provides all the interconnections required to bias and operate the system. The channel dissipates 1.6 mW. The complete 14-pixel unit covers an area of 210 mm 2 , dissipates 12 mW cm -2 , and can be tiled to cover an arbitrarily large detection area. We measured a preliminary resolution of 172 eV at -35 C on the 6 keV peak of a 55 Fe source

  11. 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.

  12. Pollen structure visualization using high-resolution laboratory-based hard X-ray tomography.

    Science.gov (United States)

    Li, Qiong; Gluch, Jürgen; Krüger, Peter; Gall, Martin; Neinhuis, Christoph; Zschech, Ehrenfried

    2016-10-14

    A laboratory-based X-ray microscope is used to investigate the 3D structure of unstained whole pollen grains. For the first time, high-resolution laboratory-based hard X-ray microscopy is applied to study pollen grains. Based on the efficient acquisition of statistically relevant information-rich images using Zernike phase contrast, both surface- and internal structures of pine pollen - including exine, intine and cellular structures - are clearly visualized. The specific volumes of these structures are calculated from the tomographic data. The systematic three-dimensional study of pollen grains provides morphological and structural information about taxonomic characters that are essential in palynology. Such studies have a direct impact on disciplines such as forestry, agriculture, horticulture, plant breeding and biodiversity. Copyright © 2016 Elsevier Inc. All rights reserved.

  13. Measurement of high-energy (10–60 keV) x-ray spectral line widths with eV accuracy

    Energy Technology Data Exchange (ETDEWEB)

    Seely, J. F., E-mail: seelyjf@gmail.com; Feldman, U. [Artep Inc., 2922 Excelsior Springs Court, Ellicott City, Maryland 21042 (United States); Glover, J. L.; Hudson, L. T.; Ralchenko, Y.; Henins, Albert [National Institute of Standards and Technology, Gaithersburg, Maryland 20899 (United States); Pereira, N. [Ecopulse Inc., P. O. Box 528, Springfield, Virginia 22152 (United States); Di Stefano, C. A.; Kuranz, C. C.; Drake, R. P. [University of Michigan, Ann Arbor, Michigan 48109 (United States); Chen, Hui; Williams, G. J.; Park, J. [Lawrence Livermore National Laboratory, Livermore, California 94551 (United States)

    2014-11-15

    A high resolution crystal spectrometer utilizing a crystal in transmission geometry has been developed and experimentally optimized to measure the widths of emission lines in the 10–60 keV energy range with eV accuracy. The spectrometer achieves high spectral resolution by utilizing crystal planes with small lattice spacings (down to 2d = 0.099 nm), a large crystal bending radius and Rowland circle diameter (965 mm), and an image plate detector with high spatial resolution (60 μm in the case of the Fuji TR image plate). High resolution W L-shell and K-shell laboratory test spectra in the 10–60 keV range and Ho K-shell spectra near 47 keV recorded at the LLNL Titan laser facility are presented. The Ho K-shell spectra are the highest resolution hard x-ray spectra recorded from a solid target irradiated by a high-intensity laser.

  14. Large microcalorimeter arrays for high-resolution X- and gamma-rayspectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Hoover, A.S., E-mail: ahoover@lanl.gov [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Hoteling, N.; Rabin, M.W. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Ullom, J.N.; Bennett, D.A. [National Institute of Standards and Technology, Boulder, CO 80305 (United States); Karpius, P.J.; Vo, D.T. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Doriese, W.B.; Hilton, G.C.; Horansky, R.D.; Irwin, K.D.; Kotsubo, V. [National Institute of Standards and Technology, Boulder, CO 80305 (United States); Lee, D.W. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Vale, L.R. [National Institute of Standards and Technology, Boulder, CO 80305 (United States)

    2011-10-01

    Microcalorimeter detectors provide unprecedented energy resolution for the measurement of X-rays and soft gamma-rays. Energy resolution in the 100 keV region can be up to an order of magnitude better than planar high-purity germanium (HPGe) detectors. The technology is well-suited to analysis of materials with complex spectra presenting closely spaced photopeaks. One application area is the measurement and assay of nuclear materials for safeguards and fuel cycle applications. In this paper, we discuss the operation and performance of a 256-pixel array, and present results of a head-to-head comparison of isotopic determination measurements with high-purity germanium using a plutonium standard. We show that the uncertainty of a single measurement is smaller for the microcalorimeter data compared to the HPGe data when photopeak areas are equal. We identify several key areas where analysis codes can be optimized that will likely lead to improvement in the microcalorimeter performance.

  15. Sensitivity Analysis of X-ray Spectra from Scanning Electron Microscopes

    Energy Technology Data Exchange (ETDEWEB)

    Miller, Thomas Martin [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Patton, Bruce W. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Weber, Charles F. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Bekar, Kursat B. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2014-10-01

    The primary goal of this project is to evaluate x-ray spectra generated within a scanning electron microscope (SEM) to determine elemental composition of small samples. This will be accomplished by performing Monte Carlo simulations of the electron and photon interactions in the sample and in the x-ray detector. The elemental inventories will be determined by an inverse process that progressively reduces the difference between the measured and simulated x-ray spectra by iteratively adjusting composition and geometric variables in the computational model. The intended benefit of this work will be to develop a method to perform quantitative analysis on substandard samples (heterogeneous phases, rough surfaces, small sizes, etc.) without involving standard elemental samples or empirical matrix corrections (i.e., true standardless quantitative analysis).

  16. Soft X ray spectrometry at high count rates

    International Nuclear Information System (INIS)

    Blanc, P.; Brouquet, P.; Uhre, N.

    1978-06-01

    Two modifications of the classical method of X-ray spectrometry by a semi-conductor diode permit a count rate of 10 5 c/s with an energy resolution of 350 eV. With a specially constructed pulse height analyzer, this detector can measure four spectra of 5 ms each, in the range of 1-30 keV, during a plasma shot

  17. Novel Hybrid CMOS X-ray Detector Developments for Future Large Area and High Resolution X-ray Astronomy Missions

    Science.gov (United States)

    Falcone, Abe

    In the coming years, X-ray astronomy will require new soft X-ray detectors that can be read very quickly with low noise and can achieve small pixel sizes over a moderately large focal plane area. These requirements will be present for a variety of X-ray missions that will attempt to address science that was highly ranked by the 2010 Decadal Survey, including missions with science that overlaps with that of IXO and Athena, as well as other missions addressing science topics beyond those of IXO and Athena. An X-ray Surveyor mission was recently chosen by NASA for study by a Science & Technology Definition Team (STDT) so it can be considered as an option for an upcom-ing flagship mission. A mission such as this was endorsed by the NASA long term planning document entitled "Enduring Quests, Daring Visions," and a detailed description of one possible reali-zation of such a mission has been referred to as SMART-X, which was described in a recent NASA RFI response. This provides an example of a future mission concept with these requirements since it has high X-ray throughput and excellent spatial resolution. We propose to continue to modify current active pixel sensor designs, in particular the hybrid CMOS detectors that we have been working with for several years, and implement new in-pixel technologies that will allow us to achieve these ambitious and realistic requirements on a timeline that will make them available to upcoming X-ray missions. This proposal is a continuation of our program that has been work-ing on these developments for the past several years. The first 3 years of the program led to the development of a new circuit design for each pixel, which has now been shown to be suitable for a larger detector array. The proposed activity for the next four years will be to incorporate this pixel design into a new design of a full detector array (2k×2k pixels with digital output) and to fabricate this full-sized device so it can be thoroughly tested and

  18. Quantum chemistry interpretation of x-ray spectra

    International Nuclear Information System (INIS)

    Bocharov, D.; Kuzmin, A.

    2005-01-01

    Full text: In this study, we present the results of ab initio computer simulations on X-ray absorption spectra of some perovskite-type tungsten oxides. For our calculations, we combine a periodic bulk model with Hartree-Fock method including a posteriori electron correlation corrections, as implemented in CRYSTAL98 computer code [1]. First, we describe the results of calculations performed on some bulk properties of the tungsten oxides (lattice constant and bulk modulus), in order to achieve the necessary level of agreement with available experimental and theoretical data. Our calculations on the densities of oneelectron energy states (DOS) for models of tungsten oxides are verified by experimental X-ray absorption spectra, which allow us to make correct qualitative interpretation of the latter. The main difficulties appearing during our first principles simulations will be discussed. [1] V.R. Saunders, R. Dovesi, C. Roetti, M. Causi, N.M. Harrison, R. Orlando, and C.M. Zicovich-Wilson, CRYSTAL-98 User Manual, University of Turin, 1999

  19. Polarized high-brilliance and high-resolution soft x-ray source at ELETTRA: The performance of beamline BACH

    International Nuclear Information System (INIS)

    Zangrando, M.; Zacchigna, M.; Finazzi, M.; Cocco, D.; Rochow, R.; Parmigiani, F.

    2004-01-01

    BACH, a soft x-ray beamline for polarization-dependent experiments at the Italian synchrotron radiation facility ELETTRA, was recently completed and characterized. Its performance, in terms of energy resolution, flux and polarization, is presented. Based on two APPLE II undulators, BACH covers the energy range between 35 and 1600 eV with the control of the light polarization. The monochromator is equipped with four gratings and allows one to work either in a high resolution or in a high flux mode. After the monochromator, the beamline is split into two branches with different refocusing properties. One is optimized to exploit the performance of the soft x-ray spectrometer (ComIXS) available at the beamline. Resolving powers between 12000 at 90 eV photon energy and 6600 near 867 eV were achieved using the high-resolution gratings and the smallest available slit width (10 μm). For the high-brilliance grating, which works between 290 and 1600 eV, resolving powers between 7000 at 400 eV and 2200 at 867 eV were obtained. The flux in the experimental chamber, measured with the high-resolution gratings for linearly polarized light at the best achievable resolution, ranges between 4x10 11 photons/s at 125 eV and 2x10 10 photons/s between 900 and 1250 eV. In circularly polarized mode the flux is two times larger for energies up to 380 eV. A gain of nearly one order of magnitude is obtained for the high-brilliance grating, in accordance with theoretical predictions. Flux beyond 1.3x10 11 photons/s was measured up to 1300 eV, and thus over nearly the complete energy range covered by this high-brilliance grating, with a maximum of 1.6x10 11 photons/s between 800 and 1100 eV. First results from polarization measurements confirm a polarization above 99.7% for both linearly and circularly polarized modes at low energies. Circular dichroism experiments indicate a circular polarization beyond 90% at the Fe L 2 /L 3 edge near 720 eV

  20. Determination of semi-reducing layer and applied stress through spectra emitted by an X-ray tube

    International Nuclear Information System (INIS)

    Santos, Josilene C.; Gonzalez, Alejandro H.L.; Terini, Ricardo A.; Costa, Paulo R.

    2016-01-01

    This work describes a method for assessment of half value layer (HVL) and peak tube voltage (kVp) by means of experimental x-ray spectra measured using a CdTe detector. The work also evaluated spectrometry parameters such as dead time and count rate, and x-ray tube characteristics that can affect the assessment of these quantities. Two sets of x-ray spectra were measured: A) using Cu filters with different thicknesses and fixed tube current, and B) keeping a fixed Cu filtration and different tube current and, so, ranging the count rates. The spectrometer was energy calibrated using standard radioactive sources. kVp value was estimated by means of experimental measured x-ray spectra, using linear regression in order to search the end point of each spectrum. HVL was estimated after the correction of the measured spectra, using an analytical method implemented using Matlab® software. For comparison, HVL was also determined using a 30 cm"3 ion chamber and high purity Al filters. (author)

  1. 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.

  2. High-resolution short-exposure small-animal laboratory x-ray phase-contrast tomography

    Science.gov (United States)

    Larsson, Daniel H.; Vågberg, William; Yaroshenko, Andre; Yildirim, Ali Önder; Hertz, Hans M.

    2016-12-01

    X-ray computed tomography of small animals and their organs is an essential tool in basic and preclinical biomedical research. In both phase-contrast and absorption tomography high spatial resolution and short exposure times are of key importance. However, the observable spatial resolutions and achievable exposure times are presently limited by system parameters rather than more fundamental constraints like, e.g., dose. Here we demonstrate laboratory tomography with few-ten μm spatial resolution and few-minute exposure time at an acceptable dose for small-animal imaging, both with absorption contrast and phase contrast. The method relies on a magnifying imaging scheme in combination with a high-power small-spot liquid-metal-jet electron-impact source. The tomographic imaging is demonstrated on intact mouse, phantoms and excised lungs, both healthy and with pulmonary emphysema.

  3. Streaked, x-ray-transmission-grating spectrometer

    International Nuclear Information System (INIS)

    Ceglio, N.M.; Roth, M.; Hawryluk, A.M.

    1981-08-01

    A free standing x-ray transmission grating has been coupled with a soft x-ray streak camera to produce a time resolved x-ray spectrometer. The instrument has a temporal resolution of approx. 20 psec, is capable of covering a broad spectral range, 2 to 120 A, has high sensitivity, and is simple to use requiring no complex alignment procedure. In recent laser fusion experiments the spectrometer successfully recorded time resolved spectra over the range 10 to 120 A with a spectral resolving power, lambda/Δlambda of 4 to 50, limited primarily by source size and collimation effects

  4. Spatial power-spectra from Yohkoh soft X-ray images

    Science.gov (United States)

    Martens, Petrus C. H.; Gomez, Daniel O.

    1992-01-01

    We analyze three sequences of images from active regions, and a full disk image obtained by Yohkoh's Soft X-ray Telescope. Two sequences are from a region at center disk observed through different filters, and one sequence is from the limb. After Fourier-transforming the X-ray intensity of the images we find nearly isotropic power-spectra with an azimuthally integrated slope of -2.1 for the center disk, and -2.8 for the limb images. The full-disk picture yields a spectrum of -2.4. These results are different from the active region spectra obtained with the Normal Incidence X-ray Telescope which have a slope of the order of -3.0, and we ascribe this to the difference in temperature response between the instruments. However, both the SXT and NIXT results are consistent with coronal heating as the end result of a downward quasistatic cascade (in lengthscales) of free magnetic energy in the corona, driven by footpoint motions in the photosphere.

  5. Quasar energy distributions. I. Soft X-ray spectra of quasars

    International Nuclear Information System (INIS)

    Wilkes, B.J.; Elvis, M.

    1987-01-01

    As the initial stage of a study of quasar energy distributions (QEDs), Einstein IPC spectra of 24 quasars are presented. These are combined with previously reported IPC spectra to form a sample of 33 quasars with well-determined soft X-ray slopes. A correlation analysis shows that radio loudness, rather than redshift or luminosity, is fundamentally related to the X-ray slope. This correlation is not followed by higher energy spectra of active galaxies. Two components are required to explain both sets of results. The best-fit column densities are systematically smaller than the Galactic values. The same effect is not present in a sample of BL Lac objects, implying that the effect is intrinsic to the quasars and is caused by a low-energy turnup in the quasar spectra. 74 references

  6. Extending the methodology of X-ray crystallography to allow X-ray microscopy without X-ray optics

    International Nuclear Information System (INIS)

    Miao Jianwei; Kirz, Janos; Sayre, David; Charalambous, Pambos

    2000-01-01

    We demonstrate that the soft X-ray diffraction pattern from a micron-size noncrystalline specimen can be recorded and inverted to form a high-resolution image. The phase problem is overcome by oversampling the diffraction pattern. The image is obtained using an iterative algorithm. The technique provides a method for X-ray microscopy requiring no high-resolution X-ray optical elements or detectors. In the present work, a resolution of approximately 60 nm was obtained, but we believe that considerably higher resolution can be achieved

  7. Indirect measure of X-rays spectra using TLDs; Medicion indirecta de espectros de rayos X utilizando TLDs

    Energy Technology Data Exchange (ETDEWEB)

    Bonzi, E. V.; Mainardi, R. T. [Universidad Nacional de Cordoba, Facultad de Matematica, Astronomia y Fisica, Av. Haya de la Torre y Av. Medina Allende s/n, Ciudad Universitaria, X5016LEA Cordoba (Argentina)

    2011-10-15

    A methodology of indirect measure of X-rays spectra, emitted by conventional tubes, was developed recently and its feasibility verified in the first place by Monte Carlo simulations. For that case is intended to measure, by means of plastic scintillators, attenuation curves of dispersed beams previously. In this work were carried out measurements of attenuation curves with thermoluminescent dosimeters (TLD) to verify the kindness of the indirect measure method. The attenuation curve was also measured using an ionization chamber brand Capintec (model 192) with the purpose of making a comparison. The results of the attenuation curve measured with both dosimeters present a good resolution inside the statistical fluctuations and the spectral reconstruction using diverse parametric functions is carried out in a quick and simple way with excellent resolutions in the functional form. For this reconstruction method are of fundamental importance the following properties of the used dosimeter: in the first place the repetition of the measures, property that could check; in second place the precision of the measured data and lastly the dosimeter response, this is, the increase of the thermoluminescent signal before an increase of the photons flow of X-rays. This parameter is the gradient of the curve thermoluminescent signal versus the dose imparted to the dosimeter. The measures were realized with a generator of X-rays brand Kevex provided of a conventional tube with tungsten anti cathode that polarizes with high tension to a maximum value of 50 kV and current of 0.5 ma. (Author)

  8. Optimizing Transition Edge Sensors for High-Resolution X-ray Spectroscopy

    International Nuclear Information System (INIS)

    Saab, Tarek; Bandler, Simon R.; Boyce, Kevin; Chervenak, James A.; Figueroa-Feliciano, Enectali; Iyomoto, Naoko; Kelley, Richard L.; Kilbourne, Caroline A.; Porter, Frederick S.; Sadleir, John E.

    2006-01-01

    Transition Edge Sensors (TES) have found applications as astronomical detectors ranging from the microwave to the gamma ray energy bands. Each energy band, however, imposes a different set of requirements on the TES such as energy and timing resolution, focal plane coverage, and the mechanisms by which the signal is coupled to the detector. This paper focuses on the development of TESs optimized for the 0.1-10 keV energy range at the NASA Goddard Space Flight Center. Such detectors are suitable candidates for some of the upcoming X-ray observatories such as NeXT and Constellation-X. Ongoing efforts at producing, characterizing, and modeling such devices, as well as the latest results, are discussed

  9. The XM-1 high resolution x-ray microscope at the ALS

    International Nuclear Information System (INIS)

    Meyer-Ilse, W.; Johnson, L.E.; Bates, W.; Lucero, A.; Anderson, E.H.; Denbeaux, G.

    2000-01-01

    The XM-1 x-ray microscope was built to obtain a high throughput of high-resolution transmission images with a wide variety of thick (< 10 micron) samples. Modeled after a 'conventional' full-field microscope, the XM-1 makes use of zone plates (ZP) for the condenser and objective elements. We present an overview of the recent activities at XM-1. Over the past year many enhancements have taken place such as the use of more efficient zone plates and the development of a cryogenic sample stage. Moreover, we have been developing the spectromicroscopy capabilities of the microscope to distinguish different element and chemical states within a sample while obtaining high spatial resolution images. We report on these and other advances. Additionally, the microscope has been actively used in many fields including biology, environmental and material science. Some of these recent achievements will be highlighted as well

  10. High-intensity, subkilovolt x-ray calibration facility

    International Nuclear Information System (INIS)

    Kuckuck, R.W.; Gaines, J.L.; Ernst, R.D.

    1976-01-01

    A high-intensity subkilovolt x-ray calibration source utilizing proton-induced inner-shell atomic fluorescence of low-Z elements is described. The high photon yields and low bremsstrahlung background associated with this phenomenon are ideally suited to provide intense, nearly monoenergetic x-ray beams. The proton accelerator is a 3 mA, 300 kV Cockroft-Walton using a conventional rf hydrogen ion source. Seven remotely-selectable targets capable of heat dissipation of 5 kW/cm 2 are used to provide characteristic x-rays with energies between 100 and 1000 eV. Source strengths are of the order of 10 13 to 10 14 photons/sec. Methods of reducing spectral contamination due to hydrocarbon build-up on the target are discussed. Typical x-ray spectra (Cu-L, C-K and B-K) are shown

  11. 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.

  12. Resonant X-ray Raman scattering for Al, Si and their oxides

    International Nuclear Information System (INIS)

    Szlachetko, J.; Berset, M.; Dousse, J.-Cl.; Fennane, K.; Szlachetko, M.; Barrett, R.; Hoszowska, J.; Kubala-Kukus, A.; Pajek, M.

    2005-01-01

    High-resolution measurements of the resonant X-ray Raman scattering (RRS) of Al and Si and their oxides were performed at the European Synchrotron Radiation Facility (ESRF) in Grenoble, France, using a von Hamos Bragg-type curved crystal spectrometer. To probe the influence of chemical effects on the RRS X-ray spectra, Al 2 O 3 and SiO 2 samples were also investigated. The X-ray RRS spectra were measured at different photon beam energies tuned below the K-absorption edge. The measured spectra are compared to results of RRS calculations based on the second-order perturbation theory within the Kramers-Heisenberg approach

  13. Theoretical modeling of Comptonized X-ray spectra of super-Eddington accretion flow: Origin of hard excess in ultraluminous X-ray sources

    Science.gov (United States)

    Kitaki, Takaaki; Mineshige, Shin; Ohsuga, Ken; Kawashima, Tomohisa

    2017-12-01

    X-ray continuum spectra of super-Eddington accretion flow are studied by means of Monte Carlo radiative transfer simulations based on the radiation hydrodynamic simulation data, in which both thermal- and bulk-Compton scatterings are taken into account. We compare the calculated spectra of accretion flow around black holes with masses of MBH = 10, 102, 103, and 104 M⊙ for a fixed mass injection rate (from the computational boundary at 103 rs) of 103 LEdd/c2 (with rs, LEdd, and c being the Schwarzschild radius, the Eddington luminosity, and the speed of light, respectively). The soft X-ray spectra exhibit mass dependence in accordance with the standard-disk relation; the maximum surface temperature is scaled as T ∝ M_{ BH}^{ -1/4}. The spectra in the hard X-ray band, by contrast with soft X-ray, look to be quite similar among different models, if we normalize the radiation luminosity by MBH. This reflects that the hard component is created by thermal- and bulk-Compton scatterings of soft photons originating from an accretion flow in the overheated and/or funnel regions, the temperatures of which have no dependence on mass. The hard X-ray spectra can be reproduced by a Wien spectrum with the temperature of T ˜ 3 keV accompanied by a hard excess at photon energy above several keV. The excess spectrum can be fitted well with a power law with a photon index of Γ ˜ 3. This feature is in good agreement with that of the recent NuSTAR observations of ULXs (ultra-luminous X-ray sources).

  14. 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.

  15. Model independent method to deconvolve hard X-ray spectra

    Energy Technology Data Exchange (ETDEWEB)

    Polcaro, V.F.; Bazzano, A.; Ubertini, P.; La Padula, C. (Consiglio Nazionale delle Ricerche, Frascati (Italy). Lab. di Astrofisica Spaziale); Manchanda, R.K. (Tata Inst. of Fundamental Research, Bombay (India))

    1984-07-01

    A general purpose method to deconvolve the energy spectra detected by means of the use of a hard X-ray telescope is described. The procedure does not assume any form of input spectrum and the observed energy loss spectrum is directly deconvolved into the incident photon spectrum, the form of which can be determined independently of physical interpretation of the data. Deconvolution of the hard X-ray spectrum of Her X-1, detected during the HXR 81M experiment, by the method independent method is presented.

  16. The Mapping X-ray Fluorescence Spectrometer (MapX)

    Science.gov (United States)

    Sarrazin, P.; Blake, D. F.; Marchis, F.; Bristow, T.; Thompson, K.

    2017-12-01

    Many planetary surface processes leave traces of their actions as features in the size range 10s to 100s of microns. The Mapping X-ray Fluorescence Spectrometer (MapX) will provide elemental imaging at 100 micron spatial resolution, yielding elemental chemistry at a scale where many relict physical, chemical, or biological features can be imaged and interpreted in ancient rocks on planetary bodies and planetesimals. MapX is an arm-based instrument positioned on a rock or regolith with touch sensors. During an analysis, an X-ray source (tube or radioisotope) bombards the sample with X-rays or alpha-particles / gamma-rays, resulting in sample X-ray Fluorescence (XRF). X-rays emitted in the direction of an X-ray sensitive CCD imager pass through a 1:1 focusing lens (X-ray micro-pore Optic (MPO)) that projects a spatially resolved image of the X-rays onto the CCD. The CCD is operated in single photon counting mode so that the energies and positions of individual X-ray photons are recorded. In a single analysis, several thousand frames are both stored and processed in real-time. Higher level data products include single-element maps with a lateral spatial resolution of 100 microns and quantitative XRF spectra from ground- or instrument- selected Regions of Interest (ROI). XRF spectra from ROI are compared with known rock and mineral compositions to extrapolate the data to rock types and putative mineralogies. When applied to airless bodies and implemented with an appropriate radioisotope source for alpha-particle excitation, MapX will be able to analyze biogenic elements C, N, O, P, S, in addition to the cations of the rock-forming elements >Na, accessible with either X-ray or gamma-ray excitation. The MapX concept has been demonstrated with a series of lab-based prototypes and is currently under refinement and TRL maturation.

  17. Measurement of high energy x-ray beam penumbra with Gafchromic trade mark sign EBT radiochromic film

    International Nuclear Information System (INIS)

    Cheung Tsang; Butson, Martin J.; Yu, Peter K. N.

    2006-01-01

    High energy x-ray beam penumbra are measured using Gafchromic trade mark sign EBT film. Gafchromic trade mark sign EBT, due to its limited energy dependence and high spatial resolution provide a high level of accuracy for dose assessment in penumbral regions. The spatial resolution of film detector systems is normally limited by the scanning resolution of the densitometer. Penumbral widths (80%/20%) measured at D max were found to be 2.8, 3.0, 3.2, and 3.4 mm (±0.2 mm) using 5, 10, 20, and 30 cm square field sizes, respectively, for a 6 MV linear accelerator produced x-ray beam. This is compared to 3.2 mm±0.2 mm (Kodak EDR2) and 3.6 mm±0.2 mm (Kodak X-Omat V) at 10 cmx10 cm measured using radiographic film. Using a zero volume extrapolation technique for ionization chamber measurements, the 10 cmx10 cm field penumbra at D max was measured to be 3.1 mm, a close match to Gafchromic trade mark sign EBT results. Penumbral measurements can also be made at other depths, including the surface, as the film does not suffer significantly from dosimetric variations caused by changing x-ray energy spectra. Gafchromic trade mark sign EBT film provides an adequate measure of penumbral dose for high energy x-ray beams

  18. OSO 8 X-ray spectra of clusters of galaxies. II - Discussion

    Science.gov (United States)

    Smith, B. W.; Mushotzky, R. F.; Serlemitsos, P. J.

    1979-01-01

    An observational description of X-ray clusters of galaxies is given based on OSO 8 X-ray results for spatially integrated spectra of 20 such clusters and various correlations obtained from these results. It is found from a correlation between temperature and velocity dispersion that the X-ray core radius should be less than the galaxy core radius or, alternatively, that the polytropic index is about 1.1 for most of the 20 clusters. Analysis of a correlation between temperature and emission integral yields evidence that more massive clusters accumulate a larger fraction of their mass as intracluster gas. Galaxy densities and optical morphology, as they correlate with X-ray properties, are reexamined for indications as to how mass injection by galaxies affects the density structure of the gas. The physical arguments used to derive iron abundances from observed equivalent widths of iron line features in X-ray spectra are critically evaluated, and the associated uncertainties in abundances derived in this manner are estimated to be quite large.

  19. How to Model Super-Soft X-ray Sources?

    Science.gov (United States)

    Rauch, Thomas

    2012-07-01

    During outbursts, the surface temperatures of white dwarfs in cataclysmic variables exceed by far half a million Kelvin. In this phase, they may become the brightest super-soft sources (SSS) in the sky. Time-series of high-resolution, high S/N X-ray spectra taken during rise, maximum, and decline of their X-ray luminosity provide insights into the processes following such outbursts as well as in the surface composition of the white dwarf. Their analysis requires adequate NLTE model atmospheres. The Tuebingen Non-LTE Model-Atmosphere Package (TMAP) is a powerful tool for their calculation. We present the application of TMAP models to SSS spectra and discuss their validity.

  20. On hard X-ray spectra of accreting neutron stars

    International Nuclear Information System (INIS)

    Zheleznyakov, V.V.

    1982-01-01

    Formation of the spectra of X-ray pulsars and gamma bursters is investigated. Interpretation of a hard X-ray spectrum of pulsars containing cyclotron lines is feasible on the basis of an isothermal model of a polar spot heated due to acccretion to a neutron star. It has been ascertained that in the regions responsible for the formation of continuum radiation and lines the mode polarization is determined by a magnetized vacuum rather than by a plasma. Bearing this in mind, the influence of the magnetic field of a star on the wide wings of the cyclotron line and on its depth is discussed. The part played by the accreting column in the case of strong accretion (approx. equal to 10 19 el cm -3 ) needed for long sustaining of the high level of X-rays from a neutron star-pulsar is studied. There occur the gaps in spectrum at frequencies close to the electron gyro-frequency and its harmonics due to the screening of the hot spot by the opaque gyro-resonant layer located within the accreting column. These gaps ensure the formation of cyclotron lines in absorption irrespective of the presence of such lines in the X-ray spectrum of a polar hot spot. (orig./WL)

  1. High resolution monochromatic X-ray imaging system based on spherically bent crystals

    International Nuclear Information System (INIS)

    Aglitskiy, Y.; Lehecka, T.; Obenschain, S.; Bodner, S.; Pawley, C.; Gerber, K.; Sethian, J.; Brown, C. M.; Seely, J.; Feldman, U.; Holland, G.

    1997-01-01

    We have developed a new X-ray imaging system based on spherically curved crystals. It is designed and used for diagnostics of targets ablatively accelerated by the Nike KrF laser. The imaging system is used for plasma diagnostics of the main target and for characterization of potential backlighters. A spherically curved quartz crystal (2d=6.687 A, R=200 mm) is used to produce monochromatic backlit images with the He-like Si resonance line (1865 eV) as the source of radiation. The spatial resolution of the X-ray optical system is 3-4 μm. Time resolved backlit monochromatic images of CH planar targets driven by the Nike facility have been obtained with 6-7 μm spatial resolution

  2. Determination of half value layer and applied voltage from emitted spectra by an X-ray tube

    International Nuclear Information System (INIS)

    Santos, Josilene C.; Gonzales, Alejandro H.L.; Terini, Ricardo A.; Costa, Paulo R.

    2016-01-01

    This work describes a method for assessment of half value layer (HVL) and peak tube voltage (kVp) applied in an X-ray tube by means of experimental X-ray spectra measured using a CdTe detector. It was assessed some parameters that can affect the evaluation of these quantities such as dead time, count rate and tube current (mA). For this study, two sets of X-ray spectra were measured: Set A), spectra measurements using Cu filters with different thicknesses (1.8 - 5.4 mm) and fixed tube current; Set B), spectra measurements keeping a fixed Cu filtration and varying tube current (0.5 - 3.0 mA). The experimental setup for the Set A spectra measurements allowed the assessment of the HVL and kVp for different count rates and dead time in the detection system, while the Set B setup allowed to assess the dependence of these quantities with the tube current. The spectrometer was energy calibrated using standard Xrays radioactive sources. The tube voltage values were estimated by means of experimental measured X-ray spectra, using linear regression in order to search the end point of each spectrum. The spectra correction was performed using the stripping procedure developed for the Matlab® software and the HVL values were derived from these corrected spectra. For comparison, HVL was also determined using a 30 cm"3 ion chamber and high purity Al filters. The results show that it is possible to determine the kVp with accuracy and reproducibility using spectra with dead time of up to 10%. In spite of this, the values obtained showed a deviation of up to 7 kV, for spectra measured using the same nominal tube voltage different tube current values, indicating dependence between these two parameters. (author)

  3. Spectrometry of X-ray beams using Cadmium and Zinc Teluride detector

    International Nuclear Information System (INIS)

    Becker, Paulo Henriques Bastos

    1997-06-01

    Determination of X-ray spectra to be utilized for medical diagnostics is a complementary process to the development of procedures to be applied to the quality control of radiodiagnostics X-ray equipment. Until some years ago, that was only possible using Germanium or Silicon detectors. Both have an excellent resolution in this energy range, but present also some restrictions as there are high costs and the necessity of operating them at temperature of liquid Nitrogen, which is not always available at the measurement's place. Room temperature detectors like Cadmium Telluride and Mercury Iodine don't have these restrictions. They, however, have a lower resolution and incomplete collection of the charges produced by their interaction with radiation. With technological advance of crystal growth in general and new techniques like cooling the crystal with a Peltier cell and rise time discrimination circuits, today Cadmium Telluride detectors show a resolution very close to that from Germanium detectors. This work relates to the routine use of Cadmium and Zinc Telluride detectors for measuring X-ray spectra in loco of diagnostic X-ray units. It characterizes the properties of a commercially available detector and offers a model for stripping the measured pulse height distribution. It was also developed a collimator to allow the direct measurement of the beam. The model developed and the constructed set-up were applied to two X-ray tubes and the achieved spectra compared with some spectra available from the literature. (author)

  4. High resolution stationary digital breast tomosynthesis using distributed carbon nanotube x-ray source array.

    Science.gov (United States)

    Qian, Xin; Tucker, Andrew; Gidcumb, Emily; Shan, Jing; Yang, Guang; Calderon-Colon, Xiomara; Sultana, Shabana; Lu, Jianping; Zhou, Otto; Spronk, Derrek; Sprenger, Frank; Zhang, Yiheng; Kennedy, Don; Farbizio, Tom; Jing, Zhenxue

    2012-04-01

    The purpose of this study is to investigate the feasibility of increasing the system spatial resolution and scanning speed of Hologic Selenia Dimensions digital breast tomosynthesis (DBT) scanner by replacing the rotating mammography x-ray tube with a specially designed carbon nanotube (CNT) x-ray source array, which generates all the projection images needed for tomosynthesis reconstruction by electronically activating individual x-ray sources without any mechanical motion. The stationary digital breast tomosynthesis (s-DBT) design aims to (i) increase the system spatial resolution by eliminating image blurring due to x-ray tube motion and (ii) reduce the scanning time. Low spatial resolution and long scanning time are the two main technical limitations of current DBT technology. A CNT x-ray source array was designed and evaluated against a set of targeted system performance parameters. Simulations were performed to determine the maximum anode heat load at the desired focal spot size and to design the electron focusing optics. Field emission current from CNT cathode was measured for an extended period of time to determine the stable life time of CNT cathode for an expected clinical operation scenario. The source array was manufactured, tested, and integrated with a Selenia scanner. An electronic control unit was developed to interface the source array with the detection system and to scan and regulate x-ray beams. The performance of the s-DBT system was evaluated using physical phantoms. The spatially distributed CNT x-ray source array comprised 31 individually addressable x-ray sources covering a 30 angular span with 1 pitch and an isotropic focal spot size of 0.6 mm at full width at half-maximum. Stable operation at 28 kV(peak) anode voltage and 38 mA tube current was demonstrated with extended lifetime and good source-to-source consistency. For the standard imaging protocol of 15 views over 14, 100 mAs dose, and 2 × 2 detector binning, the projection

  5. High-resolution imaging of coronary calcifications by intense low-energy fluoroscopic X-ray obtained from synchrotron radiation

    Energy Technology Data Exchange (ETDEWEB)

    Ohtsuka, S.; Sugishita, Y.; Takeda, T.; Itai, Y.; Tada, J.; Hyodo, K.; Ando, M. [Inst. of Clinical Medicine, Univ. of Tsukuba, Ibaraki (Japan). Dept. of Cardiology

    2000-07-01

    In order to obtain an intense monochromatic low-energy X-ray from synchrotron radiation (SR) and apply it to detect coronary calcifications, the SR beam was reflected with a silicon crystal to be expanded (150 mm in height and 80 mm in width) and to be monochromatized at an energy level of 37 keV. The X-ray was intermittently irradiated to obtain dynamic imaging of 30 images/s. Images were recorded by a digital fluorography system. The low-energy X-ray from SR sharply visualized calcification of coronary arteries, while conventional X-ray could not visualize coronary calcification. The intense monochromatic low-energy X-ray from SR is sensitive, has high-resolution for imaging coronary calcification and may serve as a screening method for coronary artery disease.

  6. High-resolution high-efficiency X-ray imaging system based on the in-line Bragg magnifier and the Medipix detector

    Czech Academy of Sciences Publication Activity Database

    Vagovič, P.; Korytár, D.; Cecilia, A.; Hamann, E.; Švéda, L.; Pelliccia, D.; Hartwig, J.; Zápražný, Z.; Oberta, Peter; Dolbnya, I.; Shawney, K.; Flechsig, U.; Fiederle, M.; Baumbach, T.

    2013-01-01

    Roč. 20, č. 1 (2013), s. 153-159 ISSN 0909-0495. [International Workshop on X-Ray Damage to Biological Crystalline Samples /7./. Oxfordshire, 14.03.2012-16.03.2012] R&D Projects: GA MPO FR-TI1/412 Institutional support: RVO:68378271 Keywords : Bragg magnifie * germanium * holography * high resolution * in-line * X-ray imaging Subject RIV: BH - Optics, Masers, Lasers Impact factor: 3.022, year: 2013 http://onlinelibrary.wiley.com/doi/10.1107/S0909049512044366/pdf

  7. Laboratory characterization of Woelter x-ray optics

    International Nuclear Information System (INIS)

    Remington, B.A.; Morales, R.I.

    1994-04-01

    We have conducted an extensive series of characterization measurements of a Woe1ter incidence x-ray microscope. The measurements were carried out on 5% sectors of the Woe1ter x-ray optic in a laboratory utilizing a high brightness, ''point'' x-ray source and fall into two categories. (1) Absolute reflectance measurements as a function of x-ray energy were made with Si(Li) detectors to acquire continuum spectra prior to and after reflecting off the Woe1ter optic. (2) Spatial resolution measurements were made using back-illuminated pinholes or grids imaged onto film or an x-ray CCD camera. The depth of field was mapped out by varying the distance between the Woe1ter optic and the backlit grid

  8. 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.

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

    International Nuclear Information System (INIS)

    Finkelstein, K. D.; Pauling, A.; Brown, Z.; Jones, R.; Tarun, A.; Misra, D. S.; Jupitz, S.; Sagan, D. C.

    2016-01-01

    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.

  10. X-ray spectroscopy and dosimetry with a portable CdTe device

    International Nuclear Information System (INIS)

    Abbene, Leonardo; La Manna, Angelo; Fauci, Francesco; Gerardi, Gaetano; Stumbo, Simone; Raso, Giuseppe

    2007-01-01

    X-ray spectra and dosimetry information are very important for quality assurance (QA) and quality control (QC) in medical diagnostic X-ray systems. An accurate knowledge of the diagnostic X-ray spectra would improve the patient dose optimization, without compromising image information. In this work, we performed direct diagnostic X-ray spectra measurements with a portable device, based on a CdTe solid-state detector. The portable device is able to directly measure X-ray spectra at high photon fluence rates, as typical of clinical radiography. We investigated on the spectral performances of the system in the mammographic energy range (up to ∼40 keV). Good system response to monoenergetic photons was measured (energy resolution of 5% FWHM at 22.1 keV). We measured the molybdenum X-ray spectra produced by a mammographic X-ray unit (GE Senographe DMR) at 28 kV and 30 kV under clinical conditions. The results showed the good reproducibility of the system and low pile-up distortions. Preliminary dosimetric measurements have been regarded as exposure and half value layer (HVL) values obtained from direct measurements and from measured X-ray spectral data, and a good agreement between exposure attenuation curves and the HVL values was obtained. The results indicated that the portable device is suitable for mammographic X-ray spectroscopy under clinical conditions

  11. High-throughput, high-resolution X-ray phase contrast tomographic microscopy for visualisation of soft tissue

    Energy Technology Data Exchange (ETDEWEB)

    McDonald, S A; Marone, F; Hintermueller, C; Stampanoni, M [Swiss Light Source, Paul Scherrer Institut, 5232 Villigen PSI (Switzerland); Bensadoun, J-C; Aebischer, P, E-mail: samuel.mcdonald@psi.c [EPFL, School of Life Sciences, Station 15, 1015 Lausanne (Switzerland)

    2009-09-01

    The use of conventional absorption based X-ray microtomography can become limited for samples showing only very weak absorption contrast. However, a wide range of samples studied in biology and materials science can produce significant phase shifts of the X-ray beam, and thus the use of the phase signal can provide substantially increased contrast and therefore new and otherwise inaccessible information. The application of two approaches for high-throughput, high-resolution X-ray phase contrast tomography, both available on the TOMCAT beamline of the SLS, is illustrated. Differential Phase Contrast (DPC) imaging uses a grating interferometer and a phase-stepping technique. It has been integrated into the beamline environment on TOMCAT in terms of the fast acquisition and reconstruction of data and the availability to scan samples within an aqueous environment. The second phase contrast approach is a modified transfer of intensity approach that can yield the 3D distribution of the phase (refractive index) of a weakly absorbing object from a single tomographic dataset. These methods are being used for the evaluation of cell integrity in 3D, with the specific aim of following and analyzing progressive cell degeneration to increase knowledge of the mechanistic events of neurodegenerative disorders such as Parkinson's disease.

  12. The X-ray electronic spectra of TiC-NbC solid solution

    International Nuclear Information System (INIS)

    Cherkashenko, V.M.; Ezhov, A.V.; Nazarova, S.Z.; Kurmaev, Eh.Z.; Nojmann, M.

    2001-01-01

    X-ray photoelectronic spectra of inner levels and valency lands in TiC-NbC solid solutions were studied. Results of combining TiL α -, NbL β2.15 -, CK α - X-ray emission spectra and photoelectronic spectra of valency bands in one energy scale in reference to the Fermi level were analyzed. It is shown that a change in crystal lattice parameters, as well as charge redistribution between titanium and niobium atoms, produce a strong effect on electronic structure formation in the mixed carbides mentioned [ru

  13. Indirect measurements of X-ray spectra; Mediciones indirectas de espectros de rayos X

    Energy Technology Data Exchange (ETDEWEB)

    Mainardi, R.T. [Facultad de Matematica, Astronomia y Fisica, Universidad Nacional de Cordoba, X5000HUA Cordoba (Argentina)

    2006-07-01

    To the effects of measuring the spectral distribution of the radiation emitted by the x-ray tubes and electron accelerators, numerous procedures that are grouped in two big categories exist at the present time: direct and indirect methods. The first ones use high resolution detectors that should be positioned, together with the appropriate collimator, in the direction of the x ray beam. The user should be an expert in the use and correction of the obtained data by the different effects that affect the detector operation such as efficiency and resolution in terms of the energy of the detected radiation. The indirect procedures, although its are more simple to use, its also require a considerable space along the beam to position the ionization chamber and the necessary absorbents to construct by this way the denominated attenuation curve. We will analyze the operation principle of the indirect methods and a new proposal in which such important novelties are introduced as the beam dispersion to avoid to measure along the main beam and that of determination of the attenuation curve in simultaneous form. By this way, with a single shot of the tube, the attenuation curve is measured, being necessary at most a shot of additional calibration to know the relative response of the detectors used in the experimental array. The physical processes involved in the obtaining of an attenuation curve are very well well-known and this it finishes it can be theoretically calculated if the analytic form of the spectrum is supposed well-known. Finally, we will see a spectra reconstruction example with the Kramers parametric form and comparisons with numeric simulations carried out with broadly validated programs as well as the possibility of the use of solid state dosemeters in the obtention of the attenuation curve. (Author)

  14. Monte Carlo simulation of x-ray spectra in diagnostic radiology and mammography using MCNP4C

    Energy Technology Data Exchange (ETDEWEB)

    Ay, M R [Department of Physics and Nuclear Sciences, AmirKabir University of Technology, Tehran (Iran, Islamic Republic of); Shahriari, M [Department of Nuclear Engineering, Shahid Beheshti University, Tehran (Iran, Islamic Republic of); Sarkar, S [Department of Medical Physics, Tehran University of Medical Science, Tehran (Iran, Islamic Republic of); Adib, M [TPP Co., GE Medical Systems, Iran Authorized Distributor, Tehran (Iran, Islamic Republic of); Zaidi, H [Division of Nuclear Medicine, Geneva University Hospital, 1211 Geneva (Switzerland)

    2004-11-07

    The general purpose Monte Carlo N-particle radiation transport computer code (MCNP4C) was used for the simulation of x-ray spectra in diagnostic radiology and mammography. The electrons were transported until they slow down and stop in the target. Both bremsstrahlung and characteristic x-ray production were considered in this work. We focus on the simulation of various target/filter combinations to investigate the effect of tube voltage, target material and filter thickness on x-ray spectra in the diagnostic radiology and mammography energy ranges. The simulated x-ray spectra were compared with experimental measurements and spectra calculated by IPEM report number 78. In addition, the anode heel effect and off-axis x-ray spectra were assessed for different anode angles and target materials and the results were compared with EGS4-based Monte Carlo simulations and measured data. Quantitative evaluation of the differences between our Monte Carlo simulated and comparison spectra was performed using student's t-test statistical analysis. Generally, there is a good agreement between the simulated x-ray and comparison spectra, although there are systematic differences between the simulated and reference spectra especially in the K-characteristic x-rays intensity. Nevertheless, no statistically significant differences have been observed between IPEM spectra and the simulated spectra. It has been shown that the difference between MCNP simulated spectra and IPEM spectra in the low energy range is the result of the overestimation of characteristic photons following the normalization procedure. The transmission curves produced by MCNP4C have good agreement with the IPEM report especially for tube voltages of 50 kV and 80 kV. The systematic discrepancy for higher tube voltages is the result of systematic differences between the corresponding spectra.

  15. Monte Carlo simulation of x-ray spectra in diagnostic radiology and mammography using MCNP4C

    Science.gov (United States)

    Ay, M. R.; Shahriari, M.; Sarkar, S.; Adib, M.; Zaidi, H.

    2004-11-01

    The general purpose Monte Carlo N-particle radiation transport computer code (MCNP4C) was used for the simulation of x-ray spectra in diagnostic radiology and mammography. The electrons were transported until they slow down and stop in the target. Both bremsstrahlung and characteristic x-ray production were considered in this work. We focus on the simulation of various target/filter combinations to investigate the effect of tube voltage, target material and filter thickness on x-ray spectra in the diagnostic radiology and mammography energy ranges. The simulated x-ray spectra were compared with experimental measurements and spectra calculated by IPEM report number 78. In addition, the anode heel effect and off-axis x-ray spectra were assessed for different anode angles and target materials and the results were compared with EGS4-based Monte Carlo simulations and measured data. Quantitative evaluation of the differences between our Monte Carlo simulated and comparison spectra was performed using student's t-test statistical analysis. Generally, there is a good agreement between the simulated x-ray and comparison spectra, although there are systematic differences between the simulated and reference spectra especially in the K-characteristic x-rays intensity. Nevertheless, no statistically significant differences have been observed between IPEM spectra and the simulated spectra. It has been shown that the difference between MCNP simulated spectra and IPEM spectra in the low energy range is the result of the overestimation of characteristic photons following the normalization procedure. The transmission curves produced by MCNP4C have good agreement with the IPEM report especially for tube voltages of 50 kV and 80 kV. The systematic discrepancy for higher tube voltages is the result of systematic differences between the corresponding spectra.

  16. X-ray streak crystal spectography

    International Nuclear Information System (INIS)

    Kauffman, R.L.; Brown, T.; Medecki, H.

    1983-01-01

    We have built an x-ray streaked crystal spectrograph for making time-resolved x-ray spectral measurements. This instrument can access Bragg angles from 11 0 to 38 0 and x-ray spectra from 200 eV to greater than 10 keV. We have demonstrated resolving powers, E/δE > 200 at 1 keV and time resolution less than 20 psec. A description of the instrument and an example of the data is given

  17. New Spectral Model for Constraining Torus Covering Factors from Broadband X-Ray Spectra of Active Galactic Nuclei

    Science.gov (United States)

    Baloković, M.; Brightman, M.; Harrison, F. A.; Comastri, A.; Ricci, C.; Buchner, J.; Gandhi, P.; Farrah, D.; Stern, D.

    2018-02-01

    The basic unified model of active galactic nuclei (AGNs) invokes an anisotropic obscuring structure, usually referred to as a torus, to explain AGN obscuration as an angle-dependent effect. We present a new grid of X-ray spectral templates based on radiative transfer calculations in neutral gas in an approximately toroidal geometry, appropriate for CCD-resolution X-ray spectra (FWHM ≥ 130 eV). Fitting the templates to broadband X-ray spectra of AGNs provides constraints on two important geometrical parameters of the gas distribution around the supermassive black hole: the average column density and the covering factor. Compared to the currently available spectral templates, our model is more flexible, and capable of providing constraints on the main torus parameters in a wider range of AGNs. We demonstrate the application of this model using hard X-ray spectra from NuSTAR (3–79 keV) for four AGNs covering a variety of classifications: 3C 390.3, NGC 2110, IC 5063, and NGC 7582. This small set of examples was chosen to illustrate the range of possible torus configurations, from disk-like to sphere-like geometries with column densities below, as well as above, the Compton-thick threshold. This diversity of torus properties challenges the simple assumption of a standard geometrically and optically thick toroidal structure commonly invoked in the basic form of the unified model of AGNs. Finding broad consistency between our constraints and those from infrared modeling, we discuss how the approach from the X-ray band complements similar measurements of AGN structures at other wavelengths.

  18. High resolution monochromatic X-ray imaging system based on spherically bent crystals

    International Nuclear Information System (INIS)

    Aglitskiy, Y.; Lehecka, T.; Obenschain, S.; Bodner, S.; Pawley, C.; Gerber, K.; Sethian, J.; Brown, C.M.; Seely, J.; Feldman, U.; Holland, G.

    1997-01-01

    We have developed a new X-ray imaging system based on spherically curved crystals. It is designed and used for diagnostics of targets ablatively accelerated by the Nike KrF laser [1,2]. The imaging system is used for plasma diagnostics of the main target and for characterization of potential backlighters. A spherically curved quartz crystal (2d=6.687 Angstrom, R=200mm) is used to produce monochromatic backlit images with the He-like Si resonance line (1865 eV) as the source of radiation. The spatial resolution of the X-ray optical system is 3 endash 4 μm. Time resolved backlit monochromatic images of CH planar targets driven by the Nike facility have been obtained with 6 endash 7 μm spatial resolution. copyright 1997 American Institute of Physics

  19. Development of a lab-scale, high-resolution, tube-generated X-ray computed-tomography system for three-dimensional (3D) materials characterization

    International Nuclear Information System (INIS)

    Mertens, J.C.E.; Williams, J.J.; Chawla, Nikhilesh

    2014-01-01

    The design and construction of a modular high resolution X-ray computed tomography (XCT) system is highlighted in this paper. The design approach is detailed for meeting a specified set of instrument performance goals tailored towards experimental versatility and high resolution imaging. The XCT tool is unique in the detector and X-ray source design configuration, enabling control in the balance between detection efficiency and spatial resolution. The system package is also unique: The sample manipulation approach implemented enables a wide gamut of in situ experimentation to analyze structure evolution under applied stimulus, by optimizing scan conditions through a high degree of controllability. The component selection and design process is detailed: Incorporated components are specified, custom designs are shared, and the approach for their integration into a fully functional XCT scanner is provided. Custom designs discussed include the dual-target X-ray source cradle which maintains position and trajectory of the beam between the two X-ray target configurations with respect to a scintillator mounting and positioning assembly and the imaging sensor, as well as a novel large-format X-ray detector with enhanced adaptability. The instrument is discussed from an operational point of view, including the details of data acquisition and processing implemented for 3D imaging via micro-CT. The performance of the instrument is demonstrated on a silica-glass particle/hydroxyl-terminated-polybutadiene (HTPB) matrix binder PBX simulant. Post-scan data processing, specifically segmentation of the sample's relevant microstructure from the 3D reconstruction, is provided to demonstrate the utility of the instrument. - Highlights: • Custom built X-ray tomography system for microstructural characterization • Detector design for maximizing polychromatic X-ray detection efficiency • X-ray design offered for maximizing X-ray flux with respect to imaging resolution

  20. Theory of pump–probe ultrafast photoemission and X-ray absorption spectra

    Energy Technology Data Exchange (ETDEWEB)

    Fujikawa, Takashi, E-mail: tfujikawa@faculty.chiba-u.jp; Niki, Kaori

    2016-01-15

    Highlights: • Pump–probe ultrafast XAFS and XPS spectra are theoretically studied. • Keldysh Green's function theory is applied. • Important many-body effects are explicitly included. - Abstract: Keldysh Green's function approach is extensively used in order to derive practical formulas to analyze pump–probe ultrafast photoemission and X-ray absorption spectra. Here the pump pulse is strong enough whereas the probe X-ray pulse can be treated by use of a perturbation theory. We expand full Green's function in terms of renormalized Green's function without the interaction between electrons and probe pulse. The present theoretical formulas allow us to handle the intrinsic and extrinsic losses, and furthermore resonant effects in X-ray Absorption Fine Structures (XAFS). To understand the radiation field screening in XPS spectra, we have to use more sophisticated theoretical approach. In the ultrafast XPS and XAFS analyses the intrinsic and extrinsic loss effects can interfere as well. In the XAFS studies careful analyses are necessary to handle extrinsic losses in terms of damped photoelectron propagation. The nonequilibrium dynamics after the pump pulse irradiation is well described by use of the time-dependent Dyson orbitals. Well above the edge threshold, ultrafast photoelectron diffraction and extended X-ray absorption fine structure (EXAFS) provide us with transient structural change after the laser pump excitations. In addition to these slow processes, the rapid oscillation in time plays an important role related to pump electronic excitations. Near threshold detailed information could be obtained for the combined electronic and structural dynamics. In particular high-energy photoemission and EXAFS are not so influenced by the details of excited states by pump pulse. Random-Phase Approximation (RPA)-boson approach is introduced to derive some practical formulas for time-dependent intrinsic amplitudes.

  1. SphinX: A Fast Solar Photometer in X-rays J. Sylwester , S. Kuzin ...

    Indian Academy of Sciences (India)

    NAS solar mission. SphinX (Solar Photometer in X-rays) will use PIN silicon detectors for high time resolution (0.01 s) measurements of the solar spectra of .... right panel of Fig. 2. In this NBF concept, three fluorescing targets illuminate a single. PIN detector. The fluorescence radiation is coming from three different pure ...

  2. Spectral Resolution for Five-Element, Filtered, X-Ray Detector (XRD) Arrays Using the Methods of Backus and Gilbert

    International Nuclear Information System (INIS)

    FEHL, DAVID LEE; BIGGS, F.; CHANDLER, GORDON A.; STYGAR, WILLIAM A.

    2000-01-01

    The generalized method of Backus and Gilbert (BG) is described and applied to the inverse problem of obtaining spectra from a 5-channel, filtered array of x-ray detectors (XRD's). This diagnostic is routinely fielded on the Z facility at Sandia National Laboratories to study soft x-ray photons ((le)2300 eV), emitted by high density Z-pinch plasmas. The BG method defines spectral resolution limits on the system of response functions that are in good agreement with the unfold method currently in use. The resolution so defined is independent of the source spectrum. For noise-free, simulated data the BG approximating function is also in reasonable agreement with the source spectrum (150 eV black-body) and the unfold. This function may be used as an initial trial function for iterative methods or a regularization model

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

    Indian Academy of Sciences (India)

    the crystalline quality through full-width at half-maximum values. .... angular divergence of ∆α = 12 arc sec. X-rays generated from the monochromator were diffracted from (0 0 6) LiNbO3 atomic planes with the (+, −, −, +, +) geometry. [8].

  4. Spatial resolution in depth-controlled surface sensitive x-ray techniques

    International Nuclear Information System (INIS)

    Yun, W.B.; Viccaro, P.J.

    1992-01-01

    The spatial resolution along the surface normal and the total depth probed are two important parameters in depth-controlled surface sensitive X-ray techniques employing grazing incidence geometry. The two parameters are analyzed in terms of optical properties (refractive indices) of the media involved and parameters of the incident X-ray beam: beam divergence, X-ray energy, and spectral bandwidth. We derive analytical expressions of the required beam divergence and spectral bandwidth of the incident beam as a function of the two parameters. Sample calculations are made for X-ray energies between 0.1 and 100 keV and for solid Be, Cu, and Au, representing material matrices consisting of low, medium, and high atomic number elements. A brief discussion on obtaining the required beam divergence and spectral bandwidth from present X-ray sources and optics is given

  5. Invisible structures in the X-ray absorption spectra of actinides

    NARCIS (Netherlands)

    Kvashnina, Kristina O.; De Groot, Frank M F

    The X-ray absorption spectra of actinides are discussed with an emphasis on the fundamental effects that influence their spectral shape, including atomic multiplet theory, charge transfer theory and crystal field theory. Many actinide spectra consist of a single peak and it is shown that the use of

  6. High Resolution Adjustable Mirror Control for X-ray Astronomy

    Science.gov (United States)

    Trolier-McKinstry, Susan

    We propose to build and test thin film transistor control circuitry for a new highresolution adjustable X-ray mirror technology. This control circuitry will greatly simplify the wiring scheme to address individual actuator cells. The result will be a transformative improvement for the X-ray Surveyor mission concept: mathematical models, which fit the experimental data quite well, indicate that 0.5 arcsecond imaging is feasible through this technique utilizing thin slumped glass substrates with uncorrected angular resolution of order 5-10 arcseconds. In order to correct for figures errors in a telescope with several square meters of collecting area, millions of actuator cells must be set and held at specific voltages. It is clearly not feasible to do this via millions of wires, each one connected to an actuator. Instead, we propose to develop and test thin-film technology that operates on the same principle as megapixel computer screens. We will develop the technologies needed to build thin film piezoelectric actuators, controlled by thin film ZnO transistors, on flexible polyimide films, and to connect those films to the back surfaces of X-ray mirrors on thin glass substrates without deforming the surface. These technologies represent a promising avenue of the development of mirrors for the X-Ray Surveyor mission concept. Such a telescope will make possible detailed studies of a wide variety of astrophysical sources. One example is the Warm-Hot Intergalactic Medium (WHIM), which is thought to account for a large fraction of the normal matter in the universe but which has not been detected unambiguously to date. Another is the growth of supermassive black holes in the early universe. This proposal supports NASA's goals of technical advancement of technologies suitable for future missions, and training of graduate students.

  7. High speed gated x-ray imagers

    International Nuclear Information System (INIS)

    Kilkenny, J.D.; Bell, P.; Hanks, R.; Power, G.; Turner, R.E.; Wiedwald, J.

    1988-01-01

    Single and multi-frame gated x-ray images with time-resolution as fast as 150 psec are described. These systems are based on the gating of microchannel plates in a stripline configuration. The gating voltage comes from the avalanche breakdown of reverse biased p-n junction producing high power voltage pulses as short as 70 psec. Results from single and four frame x-ray cameras used on Nova are described. 8 refs., 9 figs

  8. Soft x-ray scanning microtomography with submicron resolution

    International Nuclear Information System (INIS)

    McNulty, I.; Haddad, W.S.; Trebes, J.E.; Anderson, E.H.

    1994-01-01

    Scanning soft x-ray microtomography was used to obtain high-resolution three-dimensional images of a microfabricated test object. Using a special rotation stage mounted on the scanning transmission x-ray microscope at the XIA Beamline at the National Synchrotron Light Source, we recorded nine two-dimensional projections of the 3D test object over an angular range of -50 degrees to +55 degrees. The x-ray wavelength was 3.6 nm and the radiation dose to the object per projection was approximately 2 x 10 6 Gy. The object consisted of two gold patterns supported on transparent silicon nitride membranes, separated by 4.75 Jim, with 100 to 300-nm wide and 65-nm thick features. We reconstructed a volumetric data set of the test object from the two-dimensional projections using an algebraic reconstruction technique algorithm. Features of the test object were resolved to ∼100 nm in transverse and longitudinal extent in three-dimensional images rendered from the volumetric set

  9. Improvement of the detector resolution in X-ray spectrometry by using the maximum entropy method

    International Nuclear Information System (INIS)

    Fernández, Jorge E.; Scot, Viviana; Giulio, Eugenio Di; Sabbatucci, Lorenzo

    2015-01-01

    In every X-ray spectroscopy measurement the influence of the detection system causes loss of information. Different mechanisms contribute to form the so-called detector response function (DRF): the detector efficiency, the escape of photons as a consequence of photoelectric or scattering interactions, the spectrum smearing due to the energy resolution, and, in solid states detectors (SSD), the charge collection artifacts. To recover the original spectrum, it is necessary to remove the detector influence by solving the so-called inverse problem. The maximum entropy unfolding technique solves this problem by imposing a set of constraints, taking advantage of the known a priori information and preserving the positive-defined character of the X-ray spectrum. This method has been included in the tool UMESTRAT (Unfolding Maximum Entropy STRATegy), which adopts a semi-automatic strategy to solve the unfolding problem based on a suitable combination of the codes MAXED and GRAVEL, developed at PTB. In the past UMESTRAT proved the capability to resolve characteristic peaks which were revealed as overlapped by a Si SSD, giving good qualitative results. In order to obtain quantitative results, UMESTRAT has been modified to include the additional constraint of the total number of photons of the spectrum, which can be easily determined by inverting the diagonal efficiency matrix. The features of the improved code are illustrated with some examples of unfolding from three commonly used SSD like Si, Ge, and CdTe. The quantitative unfolding can be considered as a software improvement of the detector resolution. - Highlights: • Radiation detection introduces distortions in X- and Gamma-ray spectrum measurements. • UMESTRAT is a graphical tool to unfold X- and Gamma-ray spectra. • UMESTRAT uses the maximum entropy method. • UMESTRAT’s new version produces unfolded spectra with quantitative meaning. • UMESTRAT is a software tool to improve the detector resolution.

  10. A Study of the Resolution of Dental Intraoral X-Ray Machines

    International Nuclear Information System (INIS)

    Kim, Seon Ju; Chung, Hyon De

    1990-01-01

    The purpose of this study was to assess the resolution and focal spot size of dental X-ray machines. Fifty dental X-ray machines were selected for measuring resolution and focal spot size. These machines were used in general dental clinics. The time on installation of the X-ray machine varies from 1 years to 10 years. The resolution of these machines was measured with the test pattern. The focal spot size of these machines was measured with the star test pattern. The following results were obtained: 1. The resolution of dental intraoral X-ray machines was not significantly changed in ten years. 2. The focal spot size of dental intraoral X-ray machines was not significantly increased in ten years. The statistical analysis between the mean focal spot size and nominal focal spot size was significant at the 0.05 level about the more than 3 years used machines.

  11. High-resolution monochromatic x-ray imaging system based on spherically bent crystals

    International Nuclear Information System (INIS)

    Aglitskiy, Y.; Lehecka, T.; Obenschain, S.; Bodner, S.; Pawley, C.; Gerber, K.; Sethian, J.; Brown, C.M.; Seely, J.; Feldman, U.; Holland, G.

    1998-01-01

    We have developed an improved x-ray imaging system based on spherically curve crystals. It is designed and used for diagnostics of targets ablatively accelerated by the Nike KrF laser. A spherically curved quartz crystal (2d=6.687 Angstrom, R=200 mm) has been used to produce monochromatic backlit images with the He-like Si resonance line (1865 eV) as the source of radiation. The spatial resolution of the x-ray optical system is 1.7 μm in selected places and 2 - 3 μm over a larger area. Time-resolved backlit monochromatic images of polystyrene planar targets driven by the Nike facility have been obtained with a spatial resolution of 2.5 μm in selected places and 5 μm over the focal spot of the Nike laser. copyright 1998 Optical Society of America

  12. High Spectral Resolution Observation of the Soft Diffuse X-ray Background in the Direction of the Galactic Anti-Center

    Science.gov (United States)

    Wulf, Dallas; Eckart, Mega E.; Galeazzi, Massimiliano; Jaeckel, Felix; Kelley, Richard L.; Kilbourne, Caroline A.; McCammon, Dan; Morgan, Kelsey M.; Porter, Frederick S.; Szymkowiak, Andrew E.

    2018-01-01

    High spectral resolution observations in the soft x-rays are necessary for understanding and modelling the hot component of the interstellar medium and its contribution to the Soft X-ray Background (SXRB). This extended source emission cannot be resolved with most wavelength dispersive spectrometers, making energy dispersive microcalorimeters the ideal choice for these observations. We present here the analysis of the most recent sounding rocket flight of the University of Wisconsin-Madison/Goddard Space Flight Center X-ray Quantum Calorimeter (XQC), a large area silicon thermistor microcalorimeter. This 111 second observation integrates a nearly 1 steradian field of view in the direction of the galactic anti-center (l, b = 165°, -5°) and features ~5 eV spectral resolution below 1 keV. Direct comparison will also be made to the previous, high-latitude observations.

  13. Galactic and extragalactic hydrogen in the X-ray spectra of Gamma Ray Bursts

    Science.gov (United States)

    Rácz, I. I.; Bagoly, Z.; Tóth, L. V.; Balázs, L. G.; Horváth, I.; Pintér, S.

    2017-07-01

    Two types of emission can be observed from gamma-ray bursts (GRBs): the prompt emission from the central engine which can be observed in gamma or X-ray (as a low energy tail) and the afterglow from the environment in X-ray and at shorter frequencies. We examined the Swift XRT spectra with the XSPEC software. The correct estimation of the galactic interstellar medium is very important because we observe the host emission together with the galactic hydrogen absorption. We found that the estimated intrinsic hydrogen column density and the X-ray flux depend heavily on the redshift and the galactic foreground hydrogen. We also found that the initial parameters of the iteration and the cosmological parameters did not have much effect on the fitting result.

  14. Relative probabilities of the uranium isotopes for thorium x-ray emission and fluorescence of uranium x-rays

    International Nuclear Information System (INIS)

    Parker, J.L.

    1991-01-01

    Both thorium x-rays from decaying uranium isotopes and self-fluoresced uranium x-rays are prominent in high-resolution gamma-ray spectra of uranium-bearing materials. Useful application of the information carried by those x-rays has been curtailed because the probabilities of the uranium isotopes for thorium x-ray emission and for uranium x-ray fluorescence have not been known. By analyzing enrichment-meter geometry spectra from uranium oxide standards whose enrichments ranged from 0.7% to 91%, relative values, primarily, have been obtained for the probabilities of both processes. Thorium x-ray emission is very heavily dominated by 235 U. In all ordinarily occurring uranium isotopic distributions, thorium x-rays may be used as a valid 235 U signature. The probability for a thorium K α1 x-ray to be emitted in the decay of a 235 U atom is 0.048 ±0.002. In infinitely thick uranium oxide materials, the relative ratios of effectiveness for self-fluorescence, on a per unit mass basis, are approximately 234 U : 235 U : 236 U : 238 U = 1.13 : 1.00 : 0.52 : 0.028. on a per decay basis, the approximate ratios are 0.00039 : 1.00 : 0.017 : 0.18. These results imply that, contrary to what has often been stated, gamma rays are far more important than alpha particles in the self-fluorescence of uranium. Because of the importance of gamma-ray self-fluorescence, the uranium x-ray yield will be somewhat influenced by the size, shape, and composition of the materials. 4 refs., 1 fig

  15. Lifetime-vibrational interference effects in resonantly excited x-ray emission spectra of CO

    Energy Technology Data Exchange (ETDEWEB)

    Skytt, P.; Glans, P.; Gunnelin, K. [Uppsala Univ. (Sweden)] [and others

    1997-04-01

    The parity selection rule for resonant X-ray emission as demonstrated for O{sub 2} and N{sub 2} can be seen as an effect of interference between coherently excited degenerate localized core states. One system where the core state degeneracy is not exact but somewhat lifted was previously studied at ALS, namely the resonant X-ray emission of amino-substituted benzene (aniline). It was shown that the X-ray fluorescence spectrum resulting from excitation of the C1s at the site of the {open_quotes}aminocarbon{close_quotes} could be described in a picture separating the excitation and the emission processes, whereas the spectrum corresponding to the quasi-degenerate carbons could not. Thus, in this case it was necessary to take interference effects between the quasi-degenerate intermediate core excited states into account in order to obtain agreement between calculations and experiment. The different vibrational levels of core excited states in molecules have energy splittings which are of the same order of magnitude as the natural lifetime broadening of core excitations in the soft X-ray range. Therefore, lifetime-vibrational interference effects are likely to appear and influence the band shapes in resonant X-ray emission spectra. Lifetime-vibrational interference has been studied in non-resonant X-ray emission, and in Auger spectra. In this report the authors discuss results of selectively excited soft X-ray fluorescence spectra of molecules, where they focus on lifetime-interference effects appearing in the band shapes.

  16. 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...

  17. Time-resolved soft x-ray spectra from laser-produced Cu plasma

    International Nuclear Information System (INIS)

    Cone, K.V.; Dunn, J.; Baldis, H.A.; May, M.J.; Purvis, M.A.; Scott, H.A.; Schneider, M.B.

    2012-01-01

    The volumetric heating of a thin copper target has been studied with time resolved x-ray spectroscopy. The copper target was heated from a plasma produced using the Lawrence Livermore National Laboratory's Compact Multipulse Terrawatt (COMET) laser. A variable spaced grating spectrometer coupled to an x-ray streak camera measured soft x-ray emission (800-1550 eV) from the back of the copper target to characterize the bulk heating of the target. Radiation hydrodynamic simulations were modeled in 2-dimensions using the HYDRA code. The target conditions calculated by HYDRA were post-processed with the atomic kinetics code CRETIN to generate synthetic emission spectra. A comparison between the experimental and simulated spectra indicates the presence of specific ionization states of copper and the corresponding electron temperatures and ion densities throughout the laser-heated copper target.

  18. TFTR horizontal high-resolution Bragg x-ray spectrometer

    International Nuclear Information System (INIS)

    Hill, K.W.; Bitter, M.; Tavernier, M.

    1984-11-01

    A bent quartz crystal spectrometer of the Johann type with a spectral resolution of lambda/Δlambda = 10,000 to 25,000 is used on TFTR to determine central plasma parameters from the spectra of heliumlike and lithiumlike metal impurity ions (Ti, Cr, Fe, and Ni). The spectra are observed along a central radial chord and are recorded by a position sensitive multiwire proportional counter with a spatial resolution of 250. Standard delay-line time-difference readout is employed. The data are histogrammed and stored in 64k of memory providing 128 time groups of 512-channel spectra. The central ion temperature and the toroidal plasma rotation are inferred from the Doppler broadening and Doppler shift of the K lines. The central electron temperature, the distribution of ionization states, and dielectronic recombination rates are obtained from satellite-to-resonance line ratios. The performance of the spectrometer is demonstrated by measurements of the Ti XXI K radiation

  19. A model independent method to deconvolve hard X-ray spectra

    International Nuclear Information System (INIS)

    Polcaro, V.F.; Bazzano, A.; Ubertini, P.; La Padula, C.

    1984-01-01

    A general purpose method to deconvolve the energy spectra detected by means of the use of a hard X-ray telescope is described. The procedure does not assume any form of input spectrum and the observed energy loss spectrum is directly deconvolved into the incident photon spectrum, the form of which can be determined independently of physical interpretation of the data. Deconvolution of the hard X-ray spectrum of Her X-1, detected during the HXR 81M experiment, by the method independent method is presented. (orig.)

  20. Analysis of x-ray spectra emitted from highly ionized atoms in the vacuum spark and laser-produced high power plasma sources

    International Nuclear Information System (INIS)

    Mandelbaum, P.

    1987-05-01

    The interest in atomic spectroscopy has greatly been reinforced in the last ten years. This gain of interest is directly related to the developments in different fields of research where hot plasmas are created. These fields include in particular controlled thermonuclear fusion research by means of inertial or magnetic confinement approaches and also the most recent efforts to achieve lasers in the XUV region. The present work is based on the specific contribution of the atomic spectroscopy group at the Hebrew University. The recent development of both theoretical and experimental tools allowed us to progress in the understanding of the highly ionized states of heavy elements. In this work the low-inductance vacuum-spark developed at the Hebrew University was used as the hot plasma source. The spectra were recorded in the 7-300 A range by means of a high-resolution extreme-grazing-incidence spectrometer developed at the Racah Institute by Profs. J.L. Schwob and B.S. Fraenkel. To the extend the spectroscopic studies to higher-Z atoms, the laser-produced plasma facility at Soreq Nuclear Center was used. In this work the spectra of the sixth row elements were recorded in the x-rays by means of a crystal spectrometer. All these experimental systems are briefly described in chapter one. Chapter two deals with the theoretical methods used in the present work for the atomic calculations. Chapter three deals with the spectra of elements of the fifth row emitted from the vacuum-spark in the 30-150 A range. These spectra as experimental data were used in order to test ab-initio computations along the NiI sequence 3d-nl transitions. The results of this work are presented in chapter four. Chapter five is devoted to the measurement and analysis of spectra emitted from the vacuum-spark by rare-earth elements. (author)

  1. Soft x-ray scanning microtomography with submicrometer resolution

    International Nuclear Information System (INIS)

    McNulty, I.; Haddad, W.S.; Trebes, J.E.; Anderson, E.H.

    1995-01-01

    Scanning soft x-ray microtomography was used to obtain high-resolution three-dimensional images of a microfabricated test object. Using a special rotation stage mounted on the scanning transmission x-ray microscope at the X1A beamline at the National Synchrotron Light Source, we recorded nine two-dimensional projections of the 3D test object over an angular range of -50 degree to +55 degree. The x-ray wavelength was 3.6 nm and the radiation dose to the object per projection was approximately 2x10 6 Gy. The object consisted of two gold patterns supported on transparent silicon nitride membranes, separated by 4.75 μm, with 100- to 300-nm-wide and 65-nm-thick features. We reconstructed a volumetric data set of the test object from the two-dimensional projections using an algebraic reconstruction technique algorithm. Features of the test object were resolved to ∼100 nm in transverse and longitudinal extent with low artifact in three-dimensional images rendered from the volumetric set

  2. 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.

  3. Reservoir core porosity in the Resende formation using 3D high-resolution X-ray computed microtomography

    International Nuclear Information System (INIS)

    Oliveira, Milena F.S.; Lima, Inaya; Lopes, Ricardo T.; Rocha, Paula Lucia F. da

    2009-01-01

    The storage capacity and production of oil are influenced, among other things, by rocks and fluids characteristics. Porosity is one of the most important characteristics to be analyzed in oil industry, mainly in oil prospection because it represents the direct capacity of storage fluids in the rocks. By definition, porosity is the ratio of pore volume to the total bulk volume of the formation, expressed in percentage, being able to be absolute or effective. The aim of this study was to calculate porosity by 3D High-Resolution X-ray Computed Microtomography using core plugs from Resende Formation which were collected in Porto Real, Rio de Janeiro State. This formation is characterized by sandstones and fine conglomerates with associated fine siliciclastic sediments, and the paleoenviroment is interpreted as a braided fluvial system. For acquisitions data, it was used a 3D high resolution microtomography system which has a microfocus X-ray tube (spot size < 5μm) and a 12-bit cooled X-ray camera (CCD fiber-optically coupled to a scintillator) operated at 100 kV and 100 μA. Twenty-two samples taken at different depths from two boreholes were analyzed. A total of 961 slices were performed with a resolution of 14.9 μm. The results demonstrated that μ-CT is a reliable and effective technique. Through the images and data it was possible to quantify the porosity and to view the size and shape of porous. (author)

  4. Experimental analysis of high-resolution soft x-ray microscopy

    International Nuclear Information System (INIS)

    Chao, Weilun; Anderson, Erik H.; Denbeaux, Gregory; Harteneck, Bruce; Pearson, Angelic L.; Olynick, Deirdre; Schneider, Gerd; Attwood, David

    2001-01-01

    The soft x-ray, full-field microscope XM-1 at Lawrence Berkeley National Laboratory's (LBNL) Advanced Light Source has already demonstrated its capability to resolve 25-nm features. This was accomplished using a micro zone plate (MZP) with an outer zone width of 25 nm. Limited by the aspect ratio of the resist used in the fabrication, the gold-plating thickness of that zone plate is around 40 nm. However, some applications, in particular, biological imaging, prefer improved efficiency, which can be achieved by high-aspect-ratio zone plates. We accomplish this by using a bilayer-resist process in the zone plate fabrication. As our first attempt, a 40-nm-outer-zone-width MZP with a nickel-plating thickness of 150 nm (aspect ratio of 4:1) was successfully fabricated. Relative to the 25-nm MZP, this zone plate is ten times more efficient. Using this high-efficiency MZP, a line test pattern with half period of 30 nm is resolved by the microscope at photon energy of 500 eV. Furthermore, with a new multilayer mirror, the XM-1 can now perform imaging up to 1.8 keV. An image of a line test pattern with half period of 40 nm has a measured modulation of 90%. The image was taken at 1.77 keV with the high-efficiency MZP with an outer zone width of 35 nm and a nickel-plating thickness of 180 nm (aspect ratio of 5:1). XM-1 provides a gateway to high-resolution imaging at high energy. To measure frequency response of the XM-1, a partially annealed gold ''island'' pattern was chosen as a test object. After comparison with the SEM image of the pattern, the microscope has the measured cutoff of 19 nm, close to the theoretical one of 17 nm. The normalized frequency response, which is the ratio of the power density of the soft x-ray image to that of the SEM image, is shown in this paper

  5. The X-ray Variability of Eta Car, 1996-2010

    Science.gov (United States)

    Corcoran, Michael F.; Hamaguchi, K.; Gull, T.; Owocki, S.; Pittard, J.

    2010-01-01

    X-ray photometry in the 2-10 keY band of the the supermassive binary star Eta Car has been measured with the Rossi X-ray Timing Explorer from 1996-2010. The ingress to X-ray minimum is consistent with a period of 2024 days. The 2009 X-ray minimum began on January 162009 and showed an unexpectedly abrupt recovery starting after 12 Feb 2009. The X-ray colors become harder about half-way through all three minima and continue until flux recovery. The behavior of the fluxes and X-ray colors for the most recent X-ray minimum, along with Chandra high resolution grating spectra at key phases suggests a significant change in the inner wind of Eta Car, a possible indicator that the star is entering a new unstable phase of mass loss.

  6. DETECTING RELATIVISTIC X-RAY JETS IN HIGH-REDSHIFT QUASARS

    Energy Technology Data Exchange (ETDEWEB)

    McKeough, Kathryn [Department of Statistics, Harvard University, Cambridge, MA 02138 (United States); Siemiginowska, Aneta; Kashyap, Vinay L.; Lee, N. P.; Harris, D. E.; Schwartz, D. A. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Cheung, C. C. [Space Science Division, Naval Research Laboratory, Washington, DC 20375-5352 (United States); Stawarz, Łukasz [Astronomical Observatory, Jagiellonian University, ul. Orla 171, 30-244, Kraków (Poland); Stein, Nathan [Department of Statistics, The Wharton School, University of Pennsylvania, 400 Jon M. Huntsman Hall, 3730 Walnut Street, Philadelphia, PA 19104-6340 (United States); Stampoulis, Vasileios; Dyk, David A. van [Statistics Section, Imperial College London, Huxley Building, South Kensington Campus, London SW7 (United Kingdom); Wardle, J. F. C. [Department of Physics, MS 057, Brandeis University, Waltham, MA 02454 (United States); Donato, Davide [CRESST and Astroparticle Physics Laboratory NASA/GSFC, Greenbelt, MD 20771 (United States); Maraschi, Laura; Tavecchio, Fabrizio, E-mail: kathrynmckeough@g.harvard.edu [INAF Osservatorio Astronomico di Brera, via Brera 28, I-20124, Milano (Italy)

    2016-12-10

    We analyze Chandra X-ray images of a sample of 11 quasars that are known to contain kiloparsec scale radio jets. The sample consists of five high-redshift ( z  ≥ 3.6) flat-spectrum radio quasars, and six intermediate redshift (2.1 <  z  < 2.9) quasars. The data set includes four sources with integrated steep radio spectra and seven with flat radio spectra. A total of 25 radio jet features are present in this sample. We apply a Bayesian multi-scale image reconstruction method to detect and measure the X-ray emission from the jets. We compute deviations from a baseline model that does not include the jet, and compare observed X-ray images with those computed with simulated images where no jet features exist. This allows us to compute p -value upper bounds on the significance that an X-ray jet is detected in a pre-determined region of interest. We detected 12 of the features unambiguously, and an additional six marginally. We also find residual emission in the cores of three quasars and in the background of one quasar that suggest the existence of unresolved X-ray jets. The dependence of the X-ray to radio luminosity ratio on redshift is a potential diagnostic of the emission mechanism, since the inverse Compton scattering of cosmic microwave background photons (IC/CMB) is thought to be redshift dependent, whereas in synchrotron models no clear redshift dependence is expected. We find that the high-redshift jets have X-ray to radio flux ratios that are marginally inconsistent with those from lower redshifts, suggesting that either the X-ray emissions are due to the IC/CMB rather than the synchrotron process, or that high-redshift jets are qualitatively different.

  7. High-speed image converter x-ray studies

    International Nuclear Information System (INIS)

    Bryukhnevitch, G.I.; Kas'yanov, Yu.S.; Korobkin, V.V.; Prokhorov, A.M.; Stepanov, B.M.; Chevokin, V.K.; Schelev, M.Ya.

    1975-01-01

    Two X-ray high-speed image-converter cameras (ICC) have been developed. In the first one a soft X-ray radiation is converted into visible light with the aid of a 0.5ns response time, plastic scintillator. The second camera incorporates a photocathode which is sensitive to visible and X-ray radiation. Its calculated temporal resolution approaches 5 to 7ps. Both developed cameras were employed for studies of X-ray radiation emitted by laser plasma. For the smooth nanosecond excited laser pulses, a noticeable amplitude modulation was recorded in all laser pulses reflected by plasma as well as in each third pulse of X-ray plasma radiation. It was also observed that the duration of X-ray plasma radiation is 20 to 40% shorter than that of the incident nanosecond laser pulses and this duration being 3 to 6 times longer than that of the picosecond irradiating pulses. The half-width of the recorded X-ray plasma pulses was 30 to 60ps. (author)

  8. STELLAR CORONAE, SOLAR FLARES: A DETAILED COMPARISON OF {sigma} GEM, HR 1099, AND THE SUN IN HIGH-RESOLUTION X-RAYS

    Energy Technology Data Exchange (ETDEWEB)

    Huenemoerder, David P. [Massachusetts Institute of Technology, Kavli Institute for Astrophysics and Space Research, 70 Vassar St., Cambridge, MA 02139 (United States); Phillips, Kenneth J. H. [Visiting Scientist, Space Research Center, Polish Academy of Sciences, 51-622, Kopernika 11, Wroclaw (Poland); Sylwester, Janusz; Sylwester, Barbara, E-mail: dph@space.mit.edu, E-mail: kennethjhphillips@yahoo.com, E-mail: js@cbk.pan.wroc.pl, E-mail: bs@cbk.pan.wroc.pl [Space Research Center, Polish Academy of Sciences, 51-622, Kopernika 11, Wroclaw (Poland)

    2013-05-10

    The Chandra High Energy Transmission Grating Spectrometer (HETG) spectra of the coronally active binary stars {sigma} Gem and HR 1099 are among the highest fluence observations for such systems taken at high spectral resolution in X-rays with this instrument. This allows us to compare their properties in detail to solar flare spectra obtained with the Russian CORONAS-F spacecraft's RESIK instrument at similar resolution in an overlapping bandpass. Here we emphasize the detailed comparisons of the 3.3-6.1 A region (including emission from highly ionized S, Si, Ar, and K) from solar flare spectra to the corresponding {sigma} Gem and HR 1099 spectra. We also model the larger wavelength range of the HETG, from 1.7 to 25 A - having emission lines from Fe, Ca, Ar, Si, Al, Mg, Ne, O, and N-to determine coronal temperatures and abundances. {sigma} Gem is a single-lined coronally active long-period binary which has a very hot corona. HR 1099 is a similar, but shorter period, double-lined system. With very deep HETG exposures we can even study emission from some of the weaker species, such as K, Na, and Al, which are important since they have the lowest first ionization potentials, a parameter well known to be correlated with elemental fractionation in the solar corona. The solar flare temperatures reach Almost-Equal-To 20 MK, comparable to the {sigma} Gem and HR 1099 coronae. During the Chandra exposures, {sigma} Gem was slowly decaying from a flare and its spectrum is well characterized by a collisional ionization equilibrium plasma with a broad temperature distribution ranging from 2 to 60 MK, peaking near 25 MK, but with substantial emission from 50 MK plasma. We have detected K XVIII and Na XI emission which allow us to set limits on their abundances. HR 1099 was also quite variable in X-rays, also in a flare state, but had no detectable K XVIII. These measurements provide new comparisons of solar and stellar coronal abundances, especially at the lowest first

  9. Changes in X-ray photoelectron spectra of yttria-tetragonal zirconia polycrystal by ion sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Watanabe, Eiko; Yoshinari, Masao [Tokyo Dental College, Oral Health Science Center, Tokyo, Chiyoda-ku (Japan)

    2016-04-15

    This paper reports changes in X-ray photoelectron spectroscopy spectra of yttria-tetragonal zirconia polycrystal (Y-TZP) brought about by Ar ion sputtering. The changes in the core-level spectra of Y-TZP suggest that preferential sputtering of oxygen occurred. A new peak was observed near 0 eV binding energy accompanied with changes in the core-level spectra by the sputtering. After 18 h in a high vacuum following the sputtering, the spectra changed by the sputtering were returned to their original shapes. In contrast, the color of Y-TZP was changed from white to pale brown by X-ray irradiation and was changed from pale brown to dark gray by ion sputtering. However, when the new peak near 0 eV decreased after 18 h, no color change was observed. Therefore, it is thought that the new peak was mainly derived from electrons trapped in various kinds of oxygen vacancies created by the sputtering in other than color centers. (orig.)

  10. Final Report on Small Particle Speciation for Forensics Analysis by Soft X-ray Scanning Transmission X-ray Microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Pacold, J. I. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Altman, A. B. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Univ. of California, Berkeley, CA (United States); Donald, S B [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Dai, Z. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Davisson, M. L. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Holliday, K S [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Knight, K. B. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Kristo, M. J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Minasian, S. G. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Nelson, A J [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Tyliszczak, T [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Booth, C. H. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Shuh, D. K. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2016-09-30

    Materials of interest for nuclear forensic science are often highly heterogeneous, containing complex mixtures of actinide compounds in a wide variety of matrices. Scanning transmission X-ray microscopy (STXM) is ideally suited to study such materials, as it can be used to chemically image specimens by acquiring X-ray absorption near-edge spectroscopy (XANES) data with 25 nm spatial resolution. In particular, STXM in the soft X-ray synchrotron radiation regime (approximately 120 – 2000 eV) can collect spectroscopic information from the actinides and light elements in a single experiment. Thus, STXM combines the chemical sensitivity of X-ray absorption spectroscopy with high spatial resolution in a single non-destructive characterization method. This report describes the application of STXM to a broad range of nuclear materials. Where possible, the spectroscopic images obtained by STXM are compared with information derived from other analytical methods, and used to make inferences about the process history of each material. STXM measurements can yield information including the morphology of a sample, “elemental maps” showing the spatial distribution of major chemical constituents, and XANES spectra from localized regions of a sample, which may show spatial variations in chemical composition.

  11. Anatomy of the AGN in NGC 5548. IX. Photoionized emission features in the soft X-ray spectra

    Science.gov (United States)

    Mao, Junjie; Kaastra, J. S.; Mehdipour, M.; Gu, Liyi; Costantini, E.; Kriss, G. A.; Bianchi, S.; Branduardi-Raymont, G.; Behar, E.; Di Gesu, L.; Ponti, G.; Petrucci, P.-O.; Ebrero, J.

    2018-04-01

    The X-ray narrow emission line region (NELR) of the archetypal Seyfert 1 galaxy NGC 5548 has been interpreted as a single-phase photoionized plasma that is absorbed by some of the warm absorber components. This scenario requires those overlaying warm absorber components to have larger distance (to the central engine) than the X-ray NELR, which is not fully consistent with the distance estimates found in the literature. Therefore, we reanalyze the high-resolution spectra obtained in 2013-2014 with the Reflection Grating Spectrometer (RGS) aboard XMM-Newton to provide an alternative interpretation of the X-ray narrow emission features. We find that the X-ray narrow emission features in NGC 5548 can be described by a two-phase photoionized plasma with different ionization parameters (logξ = 1.3 and 0.1) and kinematics (vout = -50 and -400 km s-1), and no further absorption by the warm absorber components. The X-ray and optical NELR might be the same multi-phase photoionized plasma. Both X-ray and optical NELR have comparable distances, asymmetric line profiles, and the underlying photoionized plasma is turbulent and compact in size. The X-ray NELR is not the counterpart of the UV/X-ray absorber outside the line of sight because their distances and kinematics are not consistent. In addition, X-ray broad emission features that we find in the spectrum can be accounted for by a third photoionized emission component. The RGS spectrum obtained in 2016 is analyzed as well, where the luminosity of most prominent emission lines (the O VII forbidden line and O VIII Lyα line) are the same (at a 1σ confidence level) as in 2013-2014.

  12. Transmission properties of barite mortar using X-ray spectra measured with Cd Te detector

    Energy Technology Data Exchange (ETDEWEB)

    Santos, J. C.; Mariano, L.; Costa, P. R. [Universidade de Sao Paulo, Instituto de Fisica, Rua do Matao Travessa R. 187, Cidade Universitaria, 05508-090 Sao Paulo (Brazil); Tomal, A., E-mail: josilene@usp.br [Universidade Federal de Goias, Instituto de Fisica, Campus Samambaia, 74001-970 Goiania (Brazil)

    2014-08-15

    Current methods for calculating X-ray shielding barriers do not take into account spectral distribution of the beam transmitted by the protective material. This consideration is important in dose estimations for radiation workers and general public in diagnostic radiology facilities. The aim of the present study was to estimate barite mortar attenuation curves using X-ray spectra weighted by a workload distribution. These curves were described in units of ambient dose equivalent (H (10)), since it is the radiation quantity adopted by IAEA for dose assessment in medical environment. Attenuation curves were determined using the optimized model for shielding evaluation presented by Costa and Caldas (2002). Workload distribution presented by Simpkin (1996), measured primary spectra and mass attenuation coefficients of barite mortar were used as input data in this model. X-ray beams in diagnostic energy range were generated by an industrial X-ray tube with 3 mm of aluminum additional filtration. Primary experimental spectra were measured by a Cd Te detector and corrected by the response function of detector by means of a stripping procedure. Air kerma measurements were performed using an ionization chamber for normalization purpose of the spectra. The corrected spectra presented good agreement with spectra generated by a semi-empirical model. The variation of the ambient dose equivalent as a function of barite mortar thickness was calculated. Using these data, it was estimated the optimized thickness of protective barrier needed for shielding a particular area in an X-ray imaging facility. The results obtained for primary protective barriers exhibit qualitative agreement with those presented in literature. (Author)

  13. Design and theoretical investigation of a digital x-ray detector with large area and high spatial resolution

    Science.gov (United States)

    Gui, Jianbao; Guo, Jinchuan; Yang, Qinlao; Liu, Xin; Niu, Hanben

    2007-05-01

    X-ray phase contrast imaging is a promising new technology today, but the requirements of a digital detector with large area, high spatial resolution and high sensitivity bring forward a large challenge to researchers. This paper is related to the design and theoretical investigation of an x-ray direct conversion digital detector based on mercuric iodide photoconductive layer with the latent charge image readout by photoinduced discharge (PID). Mercuric iodide has been verified having a good imaging performance (high sensitivity, low dark current, low voltage operation and good lag characteristics) compared with the other competitive materials (α-Se,PbI II,CdTe,CdZnTe) and can be easily deposited on large substrates in the manner of polycrystalline. By use of line scanning laser beam and parallel multi-electrode readout make the system have high spatial resolution and fast readout speed suitable for instant general radiography and even rapid sequence radiography.

  14. Characteristics and quality test of X-ray with CZT detector

    International Nuclear Information System (INIS)

    Rianto, Sugeng

    2000-01-01

    The study examines the use of direct measurements of x-ray spectra for testing the quality of x-ray beam by using a peltier-cooled CZT detector under different conditions. The typical calibration of the spectrometry system shows that the energy resolution of the system is 1,2 keV at 122 keV of 57 Co. The utilization CZT based spectrometer for assessing the quality of x-ray machine on its spectra show that the CZT could accurately measure the spectra at various kVp, m As and filtration, except at the kVp greater than 140 and m As higher than 2 without added filtration. A comparison of CZT with the field instruments showed that there is a reasonable agreement between the Keithley and CZT at lower energies regardless of filtration however at high energies there is a large difference.In contrast the discrepancy between the CZT and Nero increased at lower photon energies particularly for high filtration

  15. 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.

  16. ROSAT Energy Spectra of Low-Mass X-Ray Binaries

    Science.gov (United States)

    Schulz, N. S.

    1999-01-01

    The 0.1-2.4 keV bandpass of the ROSAT Position Sensitive Proportional Counter (PSPC) offers an opportunity to study the very soft X-ray continuum of bright low-mass X-ray binaries (LMXBs). In 46 pointed observations, 23 LMXBs were observed with count rates between 0.4 and 165.4 counts s-1. The survey identified a total of 29 different luminosity levels, which are compared with observations and identified spectral states from other missions. The atoll source 4U 1705-44 was observed near Eddington luminosities in an unusually high intensity state. Spectral analysis provided a measure of the interstellar column density for all 49 observations. The sensitivity of spectral fits depends strongly on column density. Fits to highly absorbed spectra are merely insensitive toward any particular spectral model. Sources with column densities well below 1022 cm-2 are best fitted by power laws, while the blackbody model gives clearly worse fits to the data. Most single-component fits from sources with low column densities, however, are not acceptable at all. The inclusion of a blackbody component in eight sources can improve the fits significantly. The obtained emission radii of less than 5 km suggest emission from the neutron star surface. In 10 sources acceptable fits can only be achieved by including soft-line components. With a spectral resolution of the PSPC of 320-450 eV, between 0.6 and 1.2 keV unresolved broad-line features were detected around 0.65, 0.85, and 1.0 keV. The line fluxes range within 10-11 and 10-12 ergs cm-2 s-1, with equivalent widths between 24 and 210 eV. In LMC X-2, 2S 0918-549, and 4U 1254-690, line emission is indicated for the first time. The soft emission observed in 4U 0614+091 compares with recent ASCA results, with a new feature indicated at 1.31 keV. The deduced line fluxes in 4U 1820-30 and Cyg X-2 showed variability of a factor of 2 within timescales of 1-2 days. Average fluxes of line components in 4U 1820-30 varied by the same factor over a

  17. Implications for gravitational lensing and the dark matter content in clusters of galaxies from spatially resolved x-ray spectra

    Science.gov (United States)

    Loewenstein, M.

    1994-01-01

    A simple method for deriving well-behaved temperature solutions to the equation of hydrostatic equilibrium for intracluster media with X-ray imaging observations is presented and applied to a series of generalized models as well as to observations of the Perseus cluster and Abell 2256. In these applications the allowed range in the ratio of nonbaryons to baryons as a function of radius is derived, taking into account the uncertainties and crude spatial resolution of the X-ray spectra and considering a range of physically reasonable mass models with various scale heights. Particular attention is paid to the central regions of the cluster, and it is found that the dark matter can be sufficiently concentrated to be consistent with the high central mass surface densities for moderate-redshift clusters from their gravitational lensing properties.

  18. The dynamic range of ultra-high-resolution cryogenic gamma-ray spectrometers

    Energy Technology Data Exchange (ETDEWEB)

    Ali, Shafinaz [Advanced Detector Group, Lawrence Livermore National Laboratory, 7000 East Avenue, L-270, Livermore, CA 94550 (United States); Terracol, Stephane F. [Advanced Detector Group, Lawrence Livermore National Laboratory, 7000 East Avenue, L-270, Livermore, CA 94550 (United States); Drury, Owen B. [Advanced Detector Group, Lawrence Livermore National Laboratory, 7000 East Avenue, L-270, Livermore, CA 94550 (United States); Friedrich, Stephan [Advanced Detector Group, Lawrence Livermore National Laboratory, 7000 East Avenue, L-270, Livermore, CA 94550 (United States)]. E-mail: friedrich1@llnl.gov

    2006-04-15

    We are developing high-resolution cryogenic gamma-ray spectrometers for nuclear science and non-proliferation applications. The gamma-ray detectors are composed of a bulk superconducting Sn foil absorber attached to a multilayer Mo/Cu transition-edge sensor (TES). The energy resolution of a detector with a 1x1x0.25 mm{sup 3} Sn absorber is 50-90 eV FWHM for {gamma}-rays up to 100 keV, and it decreases for larger absorbers. Here, we present the detector performance for different absorber volumes, and discuss the trade-offs between energy resolution and dynamic range.

  19. The Dynamic Range of Ultra-High Resolution Cryogenic Gamma-ray Spectrometers

    International Nuclear Information System (INIS)

    Ali, S; Terracol, S F; Drury, O B; Friedrich, S

    2005-01-01

    We are developing high-resolution cryogenic gamma-ray spectrometers for nuclear science and non-proliferation applications. The gamma-ray detectors are composed of a bulk superconducting Sn foil absorber attached to multilayer Mo/Cu transition-edge sensors (TES). The energy resolution achieved with a 1 x 1 x 0.25 mm 3 Sn absorber is 50 -90eV for γ-rays up to 100 keV and it decreases for large absorber sizes. We discuss the trade-offs between energy resolution and dynamic range, as well as development of TES arrays for higher count rates and better sensitivity

  20. In Situ High Resolution Synchrotron X-Ray Powder Diffraction Studies of Lithium Batteries

    DEFF Research Database (Denmark)

    Amri, Mahrez; Fitch, Andy; Norby, Poul

    2015-01-01

    allowing diffraction information to be obtained from only the active material during battery operation [2]. High resolution synchrotron x-ray powder diffraction technique has been undertaken to obtain detailed structural and compositional information during lithiation/delithiation of commercial LiFePO4...... materials [3]. We report results from the first in situ time resolved high resolution powder diffraction experiments at beamline ID22/31 at the European Synchrotron Radiation Facility, ESRF. We follow the structural changes during charge of commercial LiFePO4 based battery materials using the Rietveld...... method. Conscientious Rietveld analysis shows slight but continuous deviation of lattice parameters from those of the fully stoichiometric end members LiFePO4 and FePO4 indicating a subsequent variation of stoichiometry during cathode delithiation. The application of an intermittent current pulses during...

  1. Time-dependent nonequilibrium soft x-ray response during a spin crossover

    Energy Technology Data Exchange (ETDEWEB)

    van Veenendaal, Michel

    2018-03-01

    The rapid development of high-brilliance pulsed X-ray sources with femtosecond time resolution has created a need for a better theoretical understanding of the time-dependent soft-X-ray response of dissipative many-body quantum systems. It is demonstrated how soft-X-ray spectroscopies, such as X-ray absorption and resonant inelastic X-ray scattering at transition-metal L-edges, can provide insight into intersystem crossings, such as a spin crossover. The photoinduced doublet-to-quartet spin crossover on cobalt in Fe-Co Prussian blue analogues is used as an example to demonstrate how the X-ray response is affected by the dissipative nonequilibrium dynamics. The time-dependent soft-X-ray spectra provide a wealth of information that reflect the changes in the nonequilibrium initial state via continuously changing spectral lineshapes that cannot be decomposed into initial photoexcited and final metastable spectra, strong broadenings, a collapse of clear selection rules during the intersystem crossing, strong fluctuations in the isotropic branching ratio in X-ray absorption, and crystal-field collapse/oscillations and strongly time-dependent anti-Stokes processes in RIXS.

  2. 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.

  3. Sub-atomic resolution X-ray crystallography and neutron crystallography: promise, challenges and potential.

    Science.gov (United States)

    Blakeley, Matthew P; Hasnain, Samar S; Antonyuk, Svetlana V

    2015-07-01

    The International Year of Crystallography saw the number of macromolecular structures deposited in the Protein Data Bank cross the 100000 mark, with more than 90000 of these provided by X-ray crystallography. The number of X-ray structures determined to sub-atomic resolution (i.e. ≤1 Å) has passed 600 and this is likely to continue to grow rapidly with diffraction-limited synchrotron radiation sources such as MAX-IV (Sweden) and Sirius (Brazil) under construction. A dozen X-ray structures have been deposited to ultra-high resolution (i.e. ≤0.7 Å), for which precise electron density can be exploited to obtain charge density and provide information on the bonding character of catalytic or electron transfer sites. Although the development of neutron macromolecular crystallography over the years has been far less pronounced, and its application much less widespread, the availability of new and improved instrumentation, combined with dedicated deuteration facilities, are beginning to transform the field. Of the 83 macromolecular structures deposited with neutron diffraction data, more than half (49/83, 59%) were released since 2010. Sub-mm(3) crystals are now regularly being used for data collection, structures have been determined to atomic resolution for a few small proteins, and much larger unit-cell systems (cell edges >100 Å) are being successfully studied. While some details relating to H-atom positions are tractable with X-ray crystallography at sub-atomic resolution, the mobility of certain H atoms precludes them from being located. In addition, highly polarized H atoms and protons (H(+)) remain invisible with X-rays. Moreover, the majority of X-ray structures are determined from cryo-cooled crystals at 100 K, and, although radiation damage can be strongly controlled, especially since the advent of shutterless fast detectors, and by using limited doses and crystal translation at micro-focus beams, radiation damage can still take place. Neutron

  4. Sub-atomic resolution X-ray crystallography and neutron crystallography: promise, challenges and potential

    Directory of Open Access Journals (Sweden)

    Matthew P. Blakeley

    2015-07-01

    Full Text Available The International Year of Crystallography saw the number of macromolecular structures deposited in the Protein Data Bank cross the 100000 mark, with more than 90000 of these provided by X-ray crystallography. The number of X-ray structures determined to sub-atomic resolution (i.e. ≤1 Å has passed 600 and this is likely to continue to grow rapidly with diffraction-limited synchrotron radiation sources such as MAX-IV (Sweden and Sirius (Brazil under construction. A dozen X-ray structures have been deposited to ultra-high resolution (i.e. ≤0.7 Å, for which precise electron density can be exploited to obtain charge density and provide information on the bonding character of catalytic or electron transfer sites. Although the development of neutron macromolecular crystallography over the years has been far less pronounced, and its application much less widespread, the availability of new and improved instrumentation, combined with dedicated deuteration facilities, are beginning to transform the field. Of the 83 macromolecular structures deposited with neutron diffraction data, more than half (49/83, 59% were released since 2010. Sub-mm3 crystals are now regularly being used for data collection, structures have been determined to atomic resolution for a few small proteins, and much larger unit-cell systems (cell edges >100 Å are being successfully studied. While some details relating to H-atom positions are tractable with X-ray crystallography at sub-atomic resolution, the mobility of certain H atoms precludes them from being located. In addition, highly polarized H atoms and protons (H+ remain invisible with X-rays. Moreover, the majority of X-ray structures are determined from cryo-cooled crystals at 100 K, and, although radiation damage can be strongly controlled, especially since the advent of shutterless fast detectors, and by using limited doses and crystal translation at micro-focus beams, radiation damage can still take place

  5. Automation of an X-ray photoelectron spectrometer

    International Nuclear Information System (INIS)

    Ashury, M.R.

    2003-02-01

    The Institute of Solid State Physics of the Vienna University of Technology is established with an X-ray Photoelectron Spectrometer Kratos XSAM 800. In its original state the instrument enables measurements of photoelectron spectra in a semiautomatical mode. After mounting of the specimen an eventual surface cleaning by argon ion sputtering is possible. Next steps are setting of x-ray tube high voltage and current, start energy and energy range of spectrum and time of measurement. Data are obtained by an x-t plotter and evaluations are performed from the registration charts. If necessary, measured spectra have to be digitized by means of a scanner. In the Introduction of this thesis the principle of X-ray photoelectron spectrometry is treated including a number of practical examples. It shows that an automation allows an extension of the performance of the instrument. Details are remote controlled experiments, wider energy ranges with improved energy resolution. Furthermore, the digitized data treatment enables background subtration, determination of line positions and integrated signal strengths, and is the detection of lowlevel of lines (the peak with lowamplitude) possible. A further advantage is the computer assisted documentation and comparison of results from different specimens. After this description of the essential requirements different possible solutions of an automation are discussed. Thus, it is decided to develop a completely new hardware for a perfect control of the spectrometer. A further decision is to be made on the most efficient kind of micro processor. From the considerations follows a completely new control board with a transputer as multi tasking processor. The complete control unit consists of a digital system, an analog system and a power unit. The digital system controls settings and spectra accumulation and includes the transputer board, the pc-link card, the i/o-card and the step scanning control board. The analog system controls the

  6. Hight resolution Si(Li) X ray detector

    International Nuclear Information System (INIS)

    Yuan Xianglin; Huang Naizhang; Lin Maocai; Li Zhiyong

    1985-01-01

    This paper describes the fabrication technology of GL1221 type Si(Li) X ray detector core and the pulse light feedback colded preamplifier fitted on the detector. The energy resolution of the detector system is 165 eV (At 5.89 KeV Mn-K α X ray); the counting rate is 1020 cps, and the electronics noise is 104 eV. The performace of the detector keeps up with the business level of a foreign product of the same kind

  7. 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.

  8. First Principles Calculations for X-ray Resonant Spectra and Elastic Properties

    International Nuclear Information System (INIS)

    Yongbin Lee

    2006-01-01

    In this thesis, we discuss applications of first principles methods to x-ray resonant spectra and elastic properties calculation. We start with brief reviews about theoretical background of first principles methods, such as density functional theory, local density approximation (LDA), LDA+U, and the linear augmented plane wave (LAPW) method to solve Kohn-Sham equations. After that we discuss x-ray resonant scattering (XRMS), x-ray magnetic circular dichroism (XMCD) and the branching problem in the heavy rare earths Ledges. In the last chapter we discuss the elastic properties of the second hardest material AlMgB 14

  9. High resolution γ spectra of 40-44 MeV γ photon activation products: Part 3 - a summary of γ rays, radionuclides and nuclear interferences observed

    International Nuclear Information System (INIS)

    Williams, D.R.; Hislop, J.S.

    1980-09-01

    A table of γ rays observed in the high resolution γ ray spectra of 40 to 44 MeV γ photon activation products is presented. This table is arranged in order of increasing γ ray energy and the parent isotopes, their half-lives and their inactive precursors are identified. Nuclear interferences caused by production of an active isotope from different parent elements have been identified and evaluated quantitatively. These are also tabulated. (author)

  10. X ray spectra and qualities for use in diagnostic radiology and equipment calibration

    International Nuclear Information System (INIS)

    Souza, Karla Cristina de

    1996-12-01

    The goal of this work was the standardization of radiation qualities of diagnostic X ray equipment of the Assay Laboratory of the Institute for Radiation Protection and Dosimetry (IRD) of the National Commission of Nuclear Energy, Brazil. X ray spectra were determined from pulse height distribution measured directly on the primary beam using a high pure planar Ge detector. A program was developed to convert pulse height distribution into radiation spectra in the range from 20 to 150 keV. X ray qualities based on those used by the 'Physikalish-Technish Bundesantalt' (PTB) primary laboratory were implanted in three radiological equipment of the Assay Laboratory. These qualities simulate radiation beams on patients submitted to typical radiological examinations. Besides the spectrometric system, a reference measurement system based on an ionization chamber calibrated in air kerma was used to establish parameters such as kilovoltage, first and second half-value layer, mean energy, effective energy and inherent filtration. Our data have shown that the implantation of these radiation qualities in the Assay Laboratory results on a metrological basis for calibration of dose measurement assemblies and kV-meters, like those used by IRD to evaluate the parameters of X ray equipment around the country. A catalogue of spectral data resulting from this work is a data bank that allows various applications like dose calculation using Monte Carlo simulation techniques. (author)

  11. Lα1 satellites in X-ray emission spectra of higher - Z elements

    International Nuclear Information System (INIS)

    Poonia, S.

    2004-01-01

    Full text: The X-ray satellite spectra arising due to 2p 3/2 -1 3x -1 - 3x -1 3d -1 (x ≡ s, p, d) transition array, in elements with Z 74 to 92, have been calculated. While the energies of various transitions of the array have been determined by using available Hartree-Fock-Slater data on 1s -1 - 2p -1 3x -1 and 2p 3/2 -1 - 3x -1 , 3x' -1 Auger transition energies and their relative intensities have been estimated by considering cross - sections of singly ionized 2x -1 (x ≡ s, p) states and then of subsequent Coster-Kronig and shake off processes. The calculated spectra have been compared with the measured satellite energies in Lα1 spectra. Their intense peaks have been identified as the observed satellite lines. The one to one correspondence between the peaks in calculated spectra and the satellites in measured spectra has been established on the basis of the agreement between the separations in the peak energies and those in the measured satellite energies. It has been established that three satellites observed in the Lα 1 region of the X-ray spectra of various elements and named α', α ix and α x in order of increasing energy are mainly emitted by 2p 3/2 -1 3d -1 - 3d -2 transitions. It is observed that the satellite α' in all these spectra can be assigned to the superposition of 3 F 4 - 3 F 4 transition and that this must be most intense one out of all these satellites, contributing in order of decreasing intensity. The line α ix , has been assigned to mainly the 1 F 3 - 1 G 4 , 1 P 1 - 1 D 2 and 1 F 3 - 1 D 2 transitions. Finally, the satellite α x , reported in the spectra of elements with Z = 74-92, has been associated with the transition 3 D 3 - 3 F 4 . The possible contributions of other transitions of the 2p 3/2 -1 3x -1 - 3x -1 3d -1 (x ≡ s, p, d) array having appreciable intensities, have also been discussed

  12. xMDFF: molecular dynamics flexible fitting of low-resolution X-ray structures

    International Nuclear Information System (INIS)

    McGreevy, Ryan; Singharoy, Abhishek; Li, Qufei; Zhang, Jingfen; Xu, Dong; Perozo, Eduardo; Schulten, Klaus

    2014-01-01

    A new real-space refinement method for low-resolution X-ray crystallography is presented. The method is based on the molecular dynamics flexible fitting protocol targeted at addressing large-scale deformations of the search model to achieve refinement with minimal manual intervention. An explanation of the method is provided, augmented by results from the refinement of both synthetic and experimental low-resolution data, including an independent electrophysiological verification of the xMDFF-refined crystal structure of a voltage-sensor protein. X-ray crystallography remains the most dominant method for solving atomic structures. However, for relatively large systems, the availability of only medium-to-low-resolution diffraction data often limits the determination of all-atom details. A new molecular dynamics flexible fitting (MDFF)-based approach, xMDFF, for determining structures from such low-resolution crystallographic data is reported. xMDFF employs a real-space refinement scheme that flexibly fits atomic models into an iteratively updating electron-density map. It addresses significant large-scale deformations of the initial model to fit the low-resolution density, as tested with synthetic low-resolution maps of d-ribose-binding protein. xMDFF has been successfully applied to re-refine six low-resolution protein structures of varying sizes that had already been submitted to the Protein Data Bank. Finally, via systematic refinement of a series of data from 3.6 to 7 Å resolution, xMDFF refinements together with electrophysiology experiments were used to validate the first all-atom structure of the voltage-sensing protein Ci-VSP

  13. xMDFF: molecular dynamics flexible fitting of low-resolution X-ray structures

    Energy Technology Data Exchange (ETDEWEB)

    McGreevy, Ryan; Singharoy, Abhishek [University of Illinois at Urbana-Champaign, Urbana, IL 61801 (United States); Li, Qufei [The University of Chicago, Chicago, IL 60637 (United States); Zhang, Jingfen; Xu, Dong [University of Missouri, Columbia, MO 65211 (United States); Perozo, Eduardo [The University of Chicago, Chicago, IL 60637 (United States); Schulten, Klaus, E-mail: kschulte@ks.uiuc.edu [University of Illinois at Urbana-Champaign, Urbana, IL 61801 (United States); University of Illinois at Urbana-Champaign, Urbana, IL 61801 (United States)

    2014-09-01

    A new real-space refinement method for low-resolution X-ray crystallography is presented. The method is based on the molecular dynamics flexible fitting protocol targeted at addressing large-scale deformations of the search model to achieve refinement with minimal manual intervention. An explanation of the method is provided, augmented by results from the refinement of both synthetic and experimental low-resolution data, including an independent electrophysiological verification of the xMDFF-refined crystal structure of a voltage-sensor protein. X-ray crystallography remains the most dominant method for solving atomic structures. However, for relatively large systems, the availability of only medium-to-low-resolution diffraction data often limits the determination of all-atom details. A new molecular dynamics flexible fitting (MDFF)-based approach, xMDFF, for determining structures from such low-resolution crystallographic data is reported. xMDFF employs a real-space refinement scheme that flexibly fits atomic models into an iteratively updating electron-density map. It addresses significant large-scale deformations of the initial model to fit the low-resolution density, as tested with synthetic low-resolution maps of d-ribose-binding protein. xMDFF has been successfully applied to re-refine six low-resolution protein structures of varying sizes that had already been submitted to the Protein Data Bank. Finally, via systematic refinement of a series of data from 3.6 to 7 Å resolution, xMDFF refinements together with electrophysiology experiments were used to validate the first all-atom structure of the voltage-sensing protein Ci-VSP.

  14. Analysis of neon soft x-ray spectra from short-pulse laser-produced plasmas

    International Nuclear Information System (INIS)

    Abare, A.C.; Keane, C.J.; Crane, J.K.; DaSilva, L.B.; Lee, R.W.; Perry, M.D.; Falcone, R.W.

    1993-04-01

    We report preliminary results from the analysis of streaked soft x-ray neon spectra a gas jet target. In obtained from the interaction of a picosecond Nd:glass laser with these experiments streaked spectra show prompt harmonic emission followed by longer time duration soft x-ray line emission. The majority of the line emission observed was found to originate from Li- and Be-like Ne and the major transitions in the observed spectra have been identified. Li-like emission lines were observed to decay faster in time than Be-like transitions, suggesting that recombination is taking place. Line ratios of n=4-2 and n=3-2 transitions supported the view that these lines were optically thin and thick, respectively. The time history of Li-like Ne 2p-4d and 2p-3d lines is in good agreement with a simple adiabatic expansion model coupled to a time dependent collisional-radiative code. Further x-ray spectroscopic analysis is underway which is aimed at diagnosing plasma conditions and assessing the potential of this recombining neon plasma as a quasi-steady-state recombination x-ray laser medium

  15. An accurate method for computer-generating tungsten anode x-ray spectra from 30 to 140 kV.

    Science.gov (United States)

    Boone, J M; Seibert, J A

    1997-11-01

    A tungsten anode spectral model using interpolating polynomials (TASMIP) was used to compute x-ray spectra at 1 keV intervals over the range from 30 kV to 140 kV. The TASMIP is not semi-empirical and uses no physical assumptions regarding x-ray production, but rather interpolates measured constant potential x-ray spectra published by Fewell et al. [Handbook of Computed Tomography X-ray Spectra (U.S. Government Printing Office, Washington, D.C., 1981)]. X-ray output measurements (mR/mAs measured at 1 m) were made on a calibrated constant potential generator in our laboratory from 50 kV to 124 kV, and with 0-5 mm added aluminum filtration. The Fewell spectra were slightly modified (numerically hardened) and normalized based on the attenuation and output characteristics of a constant potential generator and metal-insert x-ray tube in our laboratory. Then, using the modified Fewell spectra of different kVs, the photon fluence phi at each 1 keV energy bin (E) over energies from 10 keV to 140 keV was characterized using polynomial functions of the form phi (E) = a0[E] + a1[E] kV + a2[E] kV2 + ... + a(n)[E] kVn. A total of 131 polynomial functions were used to calculate accurate x-ray spectra, each function requiring between two and four terms. The resulting TASMIP algorithm produced x-ray spectra that match both the quality and quantity characteristics of the x-ray system in our laboratory. For photon fluences above 10% of the peak fluence in the spectrum, the average percent difference (and standard deviation) between the modified Fewell spectra and the TASMIP photon fluence was -1.43% (3.8%) for the 50 kV spectrum, -0.89% (1.37%) for the 70 kV spectrum, and for the 80, 90, 100, 110, 120, 130 and 140 kV spectra, the mean differences between spectra were all less than 0.20% and the standard deviations were less than approximately 1.1%. The model was also extended to include the effects of generator-induced kV ripple. Finally, the x-ray photon fluence in the units of

  16. New Optimizations of Microcalorimeter Arrays for High-Resolution Imaging X-ray Spectroscopy

    Science.gov (United States)

    Kilbourne, Caroline

    We propose to continue our successful research program in developing arrays of superconducting transition-edge sensors (TES) for x-ray astrophysics. Our standard 0.3 mm TES pixel achieves better than 2.5-eV resolution, and we now make 32x32 arrays of such pixels. We have also achieved better than 1-eV resolution in smaller pixels, and promising performance in a range of position-sensitive designs. We propose to continue to advance the designs of both the single-pixel and position-sensitive microcalorimeters so that we can produce arrays suitable for several x-ray spectroscopy observatories presently in formulation. We will also investigate various array and pixel optimizations such as would be needed for large arrays for surveys, large- pixel arrays for diffuse soft x-ray measurements, or sub-arrays of fast pixels optimized for neutron-star burst spectroscopy. In addition, we will develop fabrication processes for integrating sub-arrays with very different pixel designs into a monolithic focal-plane array to simplify the design of the focal-plane assembly and make feasible new detector configurations such as the one currently baselined for AXSIO. Through a series of measurements on test devices, we have improved our understanding of the weak-link physics governing the observed resistive transitions in TES detectors. We propose to build on that work and ultimately use the results to improve the immunity of the detector to environmental magnetic fields, as well as its fundamental performance, in each of the targeted optimizations we are developing.

  17. Bright circularly polarized soft X-ray high harmonics for X-ray magnetic circular dichroism.

    Science.gov (United States)

    Fan, Tingting; Grychtol, Patrik; Knut, Ronny; Hernández-García, Carlos; Hickstein, Daniel D; Zusin, Dmitriy; Gentry, Christian; Dollar, Franklin J; Mancuso, Christopher A; Hogle, Craig W; Kfir, Ofer; Legut, Dominik; Carva, Karel; Ellis, Jennifer L; Dorney, Kevin M; Chen, Cong; Shpyrko, Oleg G; Fullerton, Eric E; Cohen, Oren; Oppeneer, Peter M; Milošević, Dejan B; Becker, Andreas; Jaroń-Becker, Agnieszka A; Popmintchev, Tenio; Murnane, Margaret M; Kapteyn, Henry C

    2015-11-17

    We demonstrate, to our knowledge, the first bright circularly polarized high-harmonic beams in the soft X-ray region of the electromagnetic spectrum, and use them to implement X-ray magnetic circular dichroism measurements in a tabletop-scale setup. Using counterrotating circularly polarized laser fields at 1.3 and 0.79 µm, we generate circularly polarized harmonics with photon energies exceeding 160 eV. The harmonic spectra emerge as a sequence of closely spaced pairs of left and right circularly polarized peaks, with energies determined by conservation of energy and spin angular momentum. We explain the single-atom and macroscopic physics by identifying the dominant electron quantum trajectories and optimal phase-matching conditions. The first advanced phase-matched propagation simulations for circularly polarized harmonics reveal the influence of the finite phase-matching temporal window on the spectrum, as well as the unique polarization-shaped attosecond pulse train. Finally, we use, to our knowledge, the first tabletop X-ray magnetic circular dichroism measurements at the N4,5 absorption edges of Gd to validate the high degree of circularity, brightness, and stability of this light source. These results demonstrate the feasibility of manipulating the polarization, spectrum, and temporal shape of high harmonics in the soft X-ray region by manipulating the driving laser waveform.

  18. Characteristics of an intrinsic germanium detector for measurement of soft x-rays from high-temperature plasmas

    International Nuclear Information System (INIS)

    Kumagai, Katsuaki; Matoba, Tohru; Funahashi, Akimasa; Kawakami, Tomohide

    1976-09-01

    An intrinsic germanium (Ge(I)) detector has been prepared for measurement of soft X-ray spectra from high-temperature tokamak plasmas. Its characteristics of photo-peak efficiency, escape-peak and Compton scattering were calibrated with standard radioisotopes and soft X-rays from the JFT-2a plasma, and compared with those of a lithium-drifted silicon (Si(Li)) detector. Features of the Ge(I) detector are as follows: (i) high detection efficiency in the high energy range, (ii) wide energy range for measurement of soft X-ray spectra, and (iii) low Compton scattering effect in measurement of continuous spectra. Its dead-layer depth is about 0.06μm, and the minimum detectable energies in the Ge(I) detector are similar to those in the Si(Li) detector. The Ge(I) detector is effective for measuring soft X-ray spectra from high-temperature tokamak plasmas. (auth.)

  19. On the Binary Nature of Massive Blue Hypergiants: High-resolution X-Ray Spectroscopy Suggests That Cyg OB2 12 is a Colliding Wind Binary

    Energy Technology Data Exchange (ETDEWEB)

    Oskinova, L. M.; Hamann, W.-R.; Shenar, T.; Sander, A. A. C.; Todt, H.; Hainich, R. [Institute for Physics and Astronomy, University Potsdam, D-14476 Potsdam (Germany); Huenemoerder, D. P. [Massachusetts Institute of Technology, Kavli Institute for Astrophysics and Space Research, 70 Vassar St., Cambridge, MA 02139 (United States); Ignace, R., E-mail: lida@astro.physik.uni-potsdam.de [Department of Physics and Astronomy, East Tennessee State University, Johnson City, TN 37663 (United States)

    2017-08-10

    The blue hypergiant Cyg OB2 12 (B3Ia{sup +}) is a representative member of the class of very massive stars in a poorly understood evolutionary stage. We obtained its high-resolution X-ray spectrum using the Chandra observatory. PoWR model atmospheres were calculated to provide realistic wind opacities and to establish the wind density structure. We find that collisional de-excitation is the dominant mechanism depopulating the metastable upper levels of the forbidden lines of the He-like ions Si xiv and Mg xii. Comparison between the model and observations reveals that X-ray emission is produced in a dense plasma, which could reside only at the photosphere or in a colliding wind zone between binary components. The observed X-ray spectra are well-fitted by thermal plasma models, with average temperatures in excess of 10 MK. The wind speed in Cyg OB2 12 is not high enough to power such high temperatures, but the collision of two winds in a binary system can be sufficient. We used archival data to investigate the X-ray properties of other blue hypergiants. In general, stars of this class are not detected as X-ray sources. We suggest that our new Chandra observations of Cyg OB2 12 can be best explained if Cyg OB2 12 is a colliding wind binary possessing a late O-type companion. This makes Cyg OB2 12 only the second binary system among the 16 known Galactic hypergiants. This low binary fraction indicates that the blue hypergiants are likely products of massive binary evolution during which they either accreted a significant amount of mass or already merged with their companions.

  20. Multiplet splitting of x-ray photoemission spectra core levels in magnetic metals

    International Nuclear Information System (INIS)

    Kowalczyk, S.P.; McFeely, F.R.; Ley, L.; Shirley, D.A.

    1975-01-01

    The results of high resolution x-ray photoemission studies of the multiplet splitting of the 3s core levels in the 3d transition metals and the 4s, 5s and 4d core levels in the lanthanide metals are reported

  1. X-ray spectral line coincidences between fluorine VIII (and IX) and transition metal lines

    International Nuclear Information System (INIS)

    Charatis, G.; Rockett, P.D.; Burkhalter, P.G.

    1983-01-01

    X-ray spectroscopy was performed in the 12 to 15 A region, recording L-shell lines from selected laser-irradiated transition metals. Line coincidences and near coincidences were identified between Fe, Cr, Mn, and Ni L-spectra, and F VIII and F IX K-shell lines. Wavelengths were determined to accuracies of 1 to 3 mA and will be utilized in selecting potential pumping candidates in future x-ray lasing schemes. High-resolution x-ray spectra were collected under controlled illumination and target conditions using 1.05 μm and 0.527 μm laser excitation with the KMS CHROMA laser

  2. Broadband X-ray spectra of the ultraluminous X-ray source Holmberg IX X-1 observed with NuSTAR, XMM-Newton, and Suzaku

    Energy Technology Data Exchange (ETDEWEB)

    Walton, D. J.; Harrison, F. A.; Grefenstette, B. W.; Fuerst, F.; Madsen, K. K.; Rana, V.; Stern, D. [Space Radiation Laboratory, California Institute of Technology, Pasadena, CA 91125 (United States); Miller, J. M. [Department of Astronomy, University of Michigan, 500 Church Street, Ann Arbor, MI 48109-1042 (United States); Bachetti, M.; Barret, D.; Webb, N. [Universite de Toulouse, UPS-OMP, IRAP, Toulouse (France); Boggs, S. E.; Craig, W. W. [Space Sciences Laboratory, University of California, Berkeley, CA 94720 (United States); Christensen, F. E. [DTU Space, National Space Institute, Technical University of Denmark, Elektrovej 327, DK-2800 Lyngby (Denmark); Fabian, A. C.; Parker, M. L. [Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA (United Kingdom); Hailey, C. J. [Columbia Astrophysics Laboratory, Columbia University, New York, NY 10027 (United States); Ptak, A.; Zhang, W. W., E-mail: dwalton@srl.caltech.edu [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States)

    2014-09-20

    We present results from the coordinated broadband X-ray observations of the extreme ultraluminous X-ray source Holmberg IX X-1 performed by NuSTAR, XMM-Newton, and Suzaku in late 2012. These observations provide the first high-quality spectra of Holmberg IX X-1 above 10 keV to date, extending the X-ray coverage of this remarkable source up to ∼30 keV. Broadband observations were undertaken at two epochs, between which Holmberg IX X-1 exhibited both flux and strong spectral variability, increasing in luminosity from L {sub X} = (1.90 ± 0.03) × 10{sup 40} erg s{sup –1} to L {sub X} = (3.35 ± 0.03) × 10{sup 40} erg s{sup –1}. Neither epoch exhibits a spectrum consistent with emission from the standard low/hard accretion state seen in Galactic black hole binaries, which would have been expected if Holmberg IX X-1 harbors a truly massive black hole accreting at substantially sub-Eddington accretion rates. The NuSTAR data confirm that the curvature observed previously in the 3-10 keV bandpass does represent a true spectral cutoff. During each epoch, the spectrum appears to be dominated by two optically thick thermal components, likely associated with an accretion disk. The spectrum also shows some evidence for a nonthermal tail at the highest energies, which may further support this scenario. The available data allow for either of the two thermal components to dominate the spectral evolution, although both scenarios require highly nonstandard behavior for thermal accretion disk emission.

  3. X-ray radiography with highly charged ions

    Science.gov (United States)

    Marrs, Roscoe E.

    2000-01-01

    An extremely small (1-250 micron FWHM) beam of slow highly charged ions deexciting on an x-ray production target generates x-ray monochromatic radiation that is passed through a specimen and detected for imaging. The resolution of the x-ray radiograms is improved and such detection is achieved with relatively low dosages of radiation passing through the specimen. An apparatus containing an electron beam ion trap (and modifications thereof) equipped with a focusing column serves as a source of ions that generate radiation projected onto an image detector. Electronic and other detectors are able to detect an increased amount of radiation per pixel than achieved by previous methods and apparati.

  4. Magnified hard x-ray microtomography: toward tomography with submicron resolution

    Science.gov (United States)

    Schroer, Christian G.; Benner, Boris; Guenzler, Til F.; Kuhlmann, Marion; Lengeler, Bruno; Rau, Christoph; Weitkamp, Timm; Snigirev, Anatoly A.; Snigireva, Irina

    2002-01-01

    Parabolic compound refractive lenses (PCRLs) are high quality imaging optics for hard x-rays that can be used as an objective lens in a new type of hard x-ray full field microscope. Using an aluminium PCRL, this new type of microscope has been shown to have a resolution of 350 nm. Further improvement of the resolution down to 50 nm can be expected using beryllium as a lens material. The large depth of field (several mm) of the microscope results in sharp projection images for samples that fit into the field of view of about 300 micrometers. This allows to combine magnified imaging with tomographic techniques. First results of magnified microtomography are shown. Contrast formation in the microscope and the consequences for tomographic reconstruction are discussed. An outlook on further developments is given.

  5. X-ray analysis and mapping by wavelength dispersive X-ray spectroscopy in an electron microscope

    International Nuclear Information System (INIS)

    Tanaka, Miyoko; Takeguchi, Masaki; Furuya, Kazuo

    2008-01-01

    A compact and easy-to-use wavelength dispersive X-ray spectrometer using a multi-capillary X-ray lens attached to a scanning (transmission) electron microscope has been tested for thin-film analysis. B-K spectra from thin-film boron compounds (B 4 C, h-BN, and B 2 O 3 ) samples showed prominent peak shifts and detailed structural differences. Mapping images of a thin W/Si double-layer sample resolved each element clearly. Additionally, a thin SiO 2 film grown on a Si substrate was imaged with O-K X-rays. Energy and spatial resolution of the system is also discussed

  6. Probing symmetry and symmetry breaking in resonant soft-x-ray fluorescence spectra of molecules

    Energy Technology Data Exchange (ETDEWEB)

    Glans, P.; Gunnelin, K.; Guo, J. [Uppsala Univ. (Sweden)] [and others

    1997-04-01

    Conventional non-resonant soft X-ray emission brings about information about electronic structure through its symmetry and polarization selectivity, the character of which is governed by simple dipole rules. For centro-symmetric molecules with the emitting atom at the inversion center these rules lead to selective emission through the required parity change. For the more common classes of molecules which have lower symmetry or for systems with degenerate core orbitals (delocalized over identical sites), it is merely the local symmetry selectivity that provides a probe of the local atomic orbital contribution to the molecular orbital. For instance, in X-ray spectra of first row species the intensities essentially map the p-density at each particular atomic site, and, in a molecular orbital picture, the contribution of the local p-type atomic orbitals in the LCAO description of the molecular orbitals. The situation is different for resonant X-ray fluorescence spectra. Here strict parity and symmetry selectivity gives rise to a strong frequency dependence for all molecules with an element of symmetry. In addition to symmetry selectivity the strong frequency dependence of resonant X-ray emission is caused by the interplay between the shape of a narrow X-ray excitation energy function and the lifetime and vibrational broadenings of the resonantly excited core states. This interplay leads to various observable effects, such as linear dispersion, resonance narrowing and emission line (Stokes) doubling. Also from the point of view of polarization selectivity, the resonantly excited X-ray spectra are much more informative than the corresponding non-resonant spectra. Examples are presented for nitrogen, oxygen, and carbon dioxide molecules.

  7. High-speed classification of coherent X-ray diffraction patterns on the K computer for high-resolution single biomolecule imaging

    Energy Technology Data Exchange (ETDEWEB)

    Tokuhisa, Atsushi [RIKEN SPring-8 Center, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148 (Japan); Arai, Junya [The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); Joti, Yasumasa [JASRI, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan); Ohno, Yoshiyuki; Kameyama, Toyohisa; Yamamoto, Keiji; Hatanaka, Masayuki; Gerofi, Balazs; Shimada, Akio; Kurokawa, Motoyoshi; Shoji, Fumiyoshi [RIKEN Advanced Institute for Computational Science, 7-1-26 Minatojima-minami-machi, Chuo-ku, Kobe, Hyogo 650-0047 (Japan); Okada, Kensuke [RIKEN SPring-8 Center, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148 (Japan); Sugimoto, Takashi [JASRI, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan); Yamaga, Mitsuhiro; Tanaka, Ryotaro [RIKEN SPring-8 Center, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148 (Japan); Yokokawa, Mitsuo; Hori, Atsushi [RIKEN Advanced Institute for Computational Science, 7-1-26 Minatojima-minami-machi, Chuo-ku, Kobe, Hyogo 650-0047 (Japan); Ishikawa, Yutaka, E-mail: ishikawa@is.s.u-tokyo.ac.jp [The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); Hatsui, Takaki, E-mail: ishikawa@is.s.u-tokyo.ac.jp [RIKEN SPring-8 Center, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148 (Japan); Go, Nobuhiro [Japan Atomic Energy Agency, 8-1-7 Umemidai, Kizugawa, Kyoto 619-0215 (Japan)

    2013-11-01

    A code with an algorithm for high-speed classification of X-ray diffraction patterns has been developed. Results obtained for a set of 1 × 10{sup 6} simulated diffraction patterns are also reported. Single-particle coherent X-ray diffraction imaging using an X-ray free-electron laser has the potential to reveal the three-dimensional structure of a biological supra-molecule at sub-nanometer resolution. In order to realise this method, it is necessary to analyze as many as 1 × 10{sup 6} noisy X-ray diffraction patterns, each for an unknown random target orientation. To cope with the severe quantum noise, patterns need to be classified according to their similarities and average similar patterns to improve the signal-to-noise ratio. A high-speed scalable scheme has been developed to carry out classification on the K computer, a 10PFLOPS supercomputer at RIKEN Advanced Institute for Computational Science. It is designed to work on the real-time basis with the experimental diffraction pattern collection at the X-ray free-electron laser facility SACLA so that the result of classification can be feedback for optimizing experimental parameters during the experiment. The present status of our effort developing the system and also a result of application to a set of simulated diffraction patterns is reported. About 1 × 10{sup 6} diffraction patterns were successfully classificatied by running 255 separate 1 h jobs in 385-node mode.

  8. High resolution X-ray scattering techniques for studying the sliding CDWS distortions, in NbSe sub 3

    CERN Document Server

    Rideau, D; Currat, R; Requardt, H; Nad, F Y; Lorenzo, J E; Brazovskii, S; Detlefs, C; Grübel, G

    2001-01-01

    The phase gradient in a sliding-charge density wave (CDW), which is observable as a longitudinal shift, q propor to partial deriv phi/partial deriv x, of the CDW satellite peak position, is due to the conversion free-electrons CDW-condensate, at the current electrodes. Using high resolution X-ray scattering techniques and time-resolved techniques, we monitor, on thin NbSe sub 3 whiskers, the shift, q(x), and its relaxation, q(t), upon switching off the current.

  9. Introduction of soft X-ray spectromicroscopy as an advanced technique for plant biopolymers research.

    Directory of Open Access Journals (Sweden)

    Chithra Karunakaran

    Full Text Available Soft X-ray absorption spectroscopy coupled with nano-scale microscopy has been widely used in material science, environmental science, and physical sciences. In this work, the advantages of soft X-ray absorption spectromicroscopy for plant biopolymer research were demonstrated by determining the chemical sensitivity of the technique to identify common plant biopolymers and to map the distributions of biopolymers in plant samples. The chemical sensitivity of soft X-ray spectroscopy to study biopolymers was determined by recording the spectra of common plant biopolymers using soft X-ray and Fourier Transform mid Infrared (FT-IR spectroscopy techniques. The soft X-ray spectra of lignin, cellulose, and polygalacturonic acid have distinct spectral features. However, there were no distinct differences between cellulose and hemicellulose spectra. Mid infrared spectra of all biopolymers were unique and there were differences between the spectra of water soluble and insoluble xylans. The advantage of nano-scale spatial resolution exploited using soft X-ray spectromicroscopy for plant biopolymer research was demonstrated by mapping plant cell wall biopolymers in a lentil stem section and compared with the FT-IR spectromicroscopy data from the same sample. The soft X-ray spectromicroscopy enables mapping of biopolymers at the sub-cellular (~30 nm resolution whereas, the limited spatial resolution in the micron scale range in the FT-IR spectromicroscopy made it difficult to identify the localized distribution of biopolymers. The advantages and limitations of soft X-ray and FT-IR spectromicroscopy techniques for biopolymer research are also discussed.

  10. High-resolution molybdenum K-edge X-ray absorption spectroscopy analyzed with time-dependent density functional theory.

    Science.gov (United States)

    Lima, Frederico A; Bjornsson, Ragnar; Weyhermüller, Thomas; Chandrasekaran, Perumalreddy; Glatzel, Pieter; Neese, Frank; DeBeer, Serena

    2013-12-28

    X-ray absorption spectroscopy (XAS) is a widely used experimental technique capable of selectively probing the local structure around an absorbing atomic species in molecules and materials. When applied to heavy elements, however, the quantitative interpretation can be challenging due to the intrinsic spectral broadening arising from the decrease in the core-hole lifetime. In this work we have used high-energy resolution fluorescence detected XAS (HERFD-XAS) to investigate a series of molybdenum complexes. The sharper spectral features obtained by HERFD-XAS measurements enable a clear assignment of the features present in the pre-edge region. Time-dependent density functional theory (TDDFT) has been previously shown to predict K-pre-edge XAS spectra of first row transition metal compounds with a reasonable degree of accuracy. Here we extend this approach to molybdenum K-edge HERFD-XAS and present the necessary calibration. Modern pure and hybrid functionals are utilized and relativistic effects are accounted for using either the Zeroth Order Regular Approximation (ZORA) or the second order Douglas-Kroll-Hess (DKH2) scalar relativistic approximations. We have found that both the predicted energies and intensities are in excellent agreement with experiment, independent of the functional used. The model chosen to account for relativistic effects also has little impact on the calculated spectra. This study provides an important calibration set for future applications of molybdenum HERFD-XAS to complex catalytic systems.

  11. Measurement of X-ray spectra by PIN photodiode: comparative study

    International Nuclear Information System (INIS)

    Costa, Paulo R.; Furquim, Tania A.C.; Herdade, Silvio B.

    1996-01-01

    Two different approaches for the evaluation of diagnostic X-ray spectra are presented : one based on a semiempirical model and other based on measurements using a silicon PIN photodiode. Measured and calculated values using typical kVp and filter combinations are compared

  12. A super-high angular resolution principle for coded-mask X-ray imaging beyond the diffraction limit of a single pinhole

    International Nuclear Information System (INIS)

    Zhang Chen; Zhang Shuangnan

    2009-01-01

    High angular resolution X-ray imaging is always useful in astrophysics and solar physics. In principle, it can be performed by using coded-mask imaging with a very long mask-detector distance. Previously, the diffraction-interference effect was thought to degrade coded-mask imaging performance dramatically at the low energy end with its very long mask-detector distance. The diffraction-interference effect is described with numerical calculations, and the diffraction-interference cross correlation reconstruction method (DICC) is developed in order to overcome the imaging performance degradation. Based on the DICC, a super-high angular resolution principle (SHARP) for coded-mask X-ray imaging is proposed. The feasibility of coded mask imaging beyond the diffraction limit of a single pinhole is demonstrated with simulations. With the specification that the mask element size is 50 x 50 μm 2 and the mask-detector distance is 50 m, the achieved angular resolution is 0.32 arcsec above about 10 keV and 0.36 arcsec at 1.24 keV (λ = 1 nm), where diffraction cannot be neglected. The on-axis source location accuracy is better than 0.02 arcsec. Potential applications for solar observations and wide-field X-ray monitors are also briefly discussed. (invited reviews)

  13. Studying atomic-resolution by X-ray fluorescence holography

    International Nuclear Information System (INIS)

    Gao Hongyi; Chen Jianwen; Xie Honglan; Zhu Huafeng; Li Ruxin; Xu Zhizhan

    2005-01-01

    In this work, the results of numerical simulations of X-ray fluorescence holograms and the reconstructed atomic images for Fe single crystal are given. The influences of the recording angles ranges and the polarization effect on the reconstruction of the atomic images are discussed. The process for removing twin images by multiple energy fluorescence holography and expanding the energy range of the incident X-rays to improve the resolution of the reconstructed images is presented

  14. Rockets for Extended Source Soft X-ray Spectroscopy

    Science.gov (United States)

    McEntaffer, Randall

    The soft X-ray background surrounds our local galactic environment yet very little is known about the physical characteristics of this plasma. A high-resolution spectrum could unlock the properties of this million degree gas but the diffuse, low intensity nature of the background have made it difficult to observe, especially with a dispersive spectrograph. Previous observations have relied on X-ray detector energy resolution which produces poorly defined spectra that are poorly fit by complex plasma models. Here we propose a series of suborbital rocket flights that will begin the characterization of this elusive source through high-resolution X-ray grating spectroscopy. The rocket-based spectrograph can resolve individual emission lines over the soft X-ray band and place tight constraints on the temperature, density, abundance, ionization state and age of the plasma. These payloads will draw heavily from the heritage gained from previous rocket missions, while also benefiting from related NASA technology development programs. The Pennsylvania State University (PSU) team has a history of designing and flying spectrometer components onboard rockets while also being scientific leaders in the field of diffuse soft X-ray astronomy. The PSU program will provide hands-on training of young scientists in the techniques of instrumental and observational X-ray astronomy. The proposed rocket program will also expose these researchers to a full experiment cycle: design, fabrication, tolerance analysis, assembly, flight-qualification, calibration, integration, launch, and data analysis; using a combination of technologies suitable for adaptation to NASA's major missions. The PSU program in suborbital X-ray astronomy represents an exciting mix of compelling science, heritage, cutting-edge technology development, and training of future scientists.

  15. High-energy X-ray diffraction studies of disordered materials

    International Nuclear Information System (INIS)

    Kohara, Shinji; Suzuya, Kentaro

    2003-01-01

    With the arrival of the latest generation of synchrotron sources and the introduction of advanced insertion devices (wigglers and undulators), the high-energy (E≥50 keV) X-ray diffraction technique has become feasible, leading to new approaches in the quantitative study of the structure of disordered materials. High-energy X-ray diffraction has several advantages: higher resolution in real space due to a wide range of scattering vector Q, smaller correction terms (especially the absorption correction), reduction of truncation errors, the feasibility of running under extreme environments, including high-temperatures and high-pressures, and the ability to make direct comparisons between X-ray and neutron diffraction data. Recently, high-energy X-ray diffraction data have been combined with neutron diffraction data from a pulsed source to provide more detailed and reliable structural information than that hitherto available

  16. Competing orbital ordering in RVO3 compounds: High-resolution x-ray diffraction and thermal expansion

    International Nuclear Information System (INIS)

    Sage, M. H.; Blake, G. R.; Palstra, T. T. M.; Marquina, C.

    2007-01-01

    We report evidence for the phase coexistence of orbital orderings of different symmetry in RVO 3 compounds with intermediate-size rare earths. Through a study by high-resolution x-ray powder diffraction and thermal expansion, we show that the competing orbital orderings are associated with the magnitude of the VO 6 octahedral tilting and magnetic exchange striction in these compounds and that the phase-separated state is stabilized by lattice strains

  17. Imaging cells and sub-cellular structures with ultrahigh resolution full-field X-ray microscopy.

    Science.gov (United States)

    Chien, C C; Tseng, P Y; Chen, H H; Hua, T E; Chen, S T; Chen, Y Y; Leng, W H; Wang, C H; Hwu, Y; Yin, G C; Liang, K S; Chen, F R; Chu, Y S; Yeh, H I; Yang, Y C; Yang, C S; Zhang, G L; Je, J H; Margaritondo, G

    2013-01-01

    Our experimental results demonstrate that full-field hard-X-ray microscopy is finally able to investigate the internal structure of cells in tissues. This result was made possible by three main factors: the use of a coherent (synchrotron) source of X-rays, the exploitation of contrast mechanisms based on the real part of the refractive index and the magnification provided by high-resolution Fresnel zone-plate objectives. We specifically obtained high-quality microradiographs of human and mouse cells with 29 nm Rayleigh spatial resolution and verified that tomographic reconstruction could be implemented with a final resolution level suitable for subcellular features. We also demonstrated that a phase retrieval method based on a wave propagation algorithm could yield good subcellular images starting from a series of defocused microradiographs. The concluding discussion compares cellular and subcellular hard-X-ray microradiology with other techniques and evaluates its potential impact on biomedical research. Copyright © 2012 Elsevier Inc. All rights reserved.

  18. Automated data processing of high-resolution mass spectra

    DEFF Research Database (Denmark)

    Hansen, Michael Adsetts Edberg; Smedsgaard, Jørn

    of the massive amounts of data. We present an automated data processing method to quantitatively compare large numbers of spectra from the analysis of complex mixtures, exploiting the full quality of high-resolution mass spectra. By projecting all detected ions - within defined intervals on both the time...... infusion of crude extracts into the source taking advantage of the high sensitivity, high mass resolution and accuracy and the limited fragmentation. Unfortunately, there has not been a comparable development in the data processing techniques to fully exploit gain in high resolution and accuracy...... infusion analyses of crude extract to find the relationship between species from several species terverticillate Penicillium, and also that the ions responsible for the segregation can be identified. Furthermore the process can automate the process of detecting unique species and unique metabolites....

  19. High-energy X-ray observations of extragalactic objects

    International Nuclear Information System (INIS)

    Pietsch, W.; Reppin, C.; Truemper, J.; Voges, W.; Lewin, W.; Kendziorra, E.; Staubert, R.

    1981-01-01

    During a balloon flight from Alice Springs, Australia, six extragalactic sources which are known as potential X-ray sources have been observed in hard X-rays (E > 20 keV). We present X-ray spectra of 3C 273 and Cen-A as well as upper limits on 3C 120, MKN 509, NGC 5506, and MR 2251-178. (orig.)

  20. Optical and x-ray alignment approaches for off-plane reflection gratings

    Science.gov (United States)

    Allured, Ryan; Donovan, Benjamin D.; DeRoo, Casey T.; Marlowe, Hannah R.; McEntaffer, Randall L.; Tutt, James H.; Cheimets, Peter N.; Hertz, Edward; Smith, Randall K.; Burwitz, Vadim; Hartner, Gisela; Menz, Benedikt

    2015-09-01

    Off-plane reflection gratings offer the potential for high-resolution, high-throughput X-ray spectroscopy on future missions. Typically, the gratings are placed in the path of a converging beam from an X-ray telescope. In the off-plane reflection grating case, these gratings must be co-aligned such that their diffracted spectra overlap at the focal plane. Misalignments degrade spectral resolution and effective area. In-situ X-ray alignment of a pair of off-plane reflection gratings in the path of a silicon pore optics module has been performed at the MPE PANTER beamline in Germany. However, in-situ X-ray alignment may not be feasible when assembling all of the gratings required for a satellite mission. In that event, optical methods must be developed to achieve spectral alignment. We have developed an alignment approach utilizing a Shack-Hartmann wavefront sensor and diffraction of an ultraviolet laser. We are fabricating the necessary hardware, and will be taking a prototype grating module to an X-ray beamline for performance testing following assembly and alignment.

  1. Simultaneous broadband observations and high-resolution X-ray spectroscopy of the transitional millisecond pulsar PSR J1023+0038

    Science.gov (United States)

    Coti Zelati, F.; Campana, S.; Braito, V.; Baglio, M. C.; D'Avanzo, P.; Rea, N.; Torres, D. F.

    2018-03-01

    We report on the first simultaneous XMM-Newton, NuSTAR, and Swift observations of the transitional millisecond pulsar PSR J1023+0038 in the X-ray active state. Our multi-wavelength campaign allowed us to investigate with unprecedented detail possible spectral variability over a broad energy range in the X-rays, as well as correlations and lags among emissions in different bands. The soft and hard X-ray emissions are significantly correlated, with no lags between the two bands. On the other hand, the X-ray emission does not correlate with the UV emission. We refine our model for the observed mode switching in terms of rapid transitions between a weak propeller regime and a rotation-powered radio pulsar state, and report on a detailed high-resolution X-ray spectroscopy using all XMM-Newton Reflection Grating Spectrometer data acquired since 2013. We discuss our results in the context of the recent discoveries on the system and of the state of the art simulations on transitional millisecond pulsars, and show how the properties of the narrow emission lines in the soft X-ray spectrum are consistent with an origin within the accretion disc.

  2. High precision wavelength measurements of X-ray lines emitted from TS-Tokamak plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Platz, P. [Association Euratom-CEA, Centre d`Etudes de Cadarache, 13 - Saint-Paul-lez-Durance (France). Dept. de Recherches sur la Fusion Controlee; Cornille, M.; Dubau, J. [Observatoire de Paris, 92 - Meudon (France)

    1996-01-01

    X-ray line spectra from highly charged impurity ions have been taken with a high-resolution Bragg-crystal spectrometer on the Tore Supra (TS) tokamak. By cross-checking the wavelengths of reference lines from the heliumlike ions Ti20 + (2.6 Angstroms) and Ar16 + (3.95 Angstroms) we first demonstrate that it is possible to measure wavelengths with a precision, {lambda}/{delta}{lambda}, of better than 50000. We than determine the wavelengths of n=3 to n=2 transitions of neonlike Ag37+ in the 4 Angstroms spectral range. (authors). 16 refs., 7 figs., 3 tabs.

  3. Soft X-ray absorption spectra of aqueous salt solutions with highly charged cations in liquid microjets

    Energy Technology Data Exchange (ETDEWEB)

    Schwartz, Craig P.; Uejio, Janel S.; Duffin, Andrew M.; Drisdell, Walter S.; Smith, Jared D.; Saykally, Richard J.

    2010-03-11

    X-ray absorption spectra of 1M aqueous solutions of indium (III) chloride, yttrium (III) bromide, lanthanum (III) chloride, tin (IV) chloride and chromium (III) chloride have been measured at the oxygen K-edge. Relatively minor changes are observed in the spectra compared to that of pure water. SnCl{sub 4} and CrCl{sub 3} exhibit a new onset feature which is attributed to formation of hydroxide or other complex molecules in the solution. At higher energy, only relatively minor, but salt-specific changes in the spectra occur. The small magnitude of the observed spectral changes is ascribed to offsetting perturbations by the cations and anions.

  4. 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.

  5. Observation of soft X-ray spectra from a Seyfert 1 and a narrow emission-line galaxy

    International Nuclear Information System (INIS)

    Singh, K.P.; Garmire, G.P.; Nousek, J.

    1985-01-01

    The 0.2-40 keV X-ray spectra of the Seyfert 1 galaxy Mrk 509 and the narrow emission-line galaxy NGC 2992 are analyzed. The results suggest the presence of a steep soft X-ray component in Mrk 509 in addition to the well-known Gamma = 1.7 component found in other active galactic nuclei in the 2-40 keV energy range. The soft X-ray component is interpreted as due to thermal emission from a hot gas, probably associated with the highly ionized gas observed to be outflowing from the galaxy. The X-ray spectrum of NGC 2992 does not show any steepening in the soft X-ray band and is consistent with a single power law (Gamma = 1.78) with very low absorbing column density of 4 x 10 to the 21st/sq cm. A model with partial covering of the nuclear X-ray source is preferred, however, to a simple model with a single power law and absorption. 34 references

  6. 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.

  7. Electron-impact-induced K plus M shell ionization in solid targets of medium-Z elements studied by means of high-resolution x-ray spectroscopy

    International Nuclear Information System (INIS)

    Ludziejewski, T.; Rymuza, P.; Sujkowski, Z.; Borchert, G.; Dousse, J.; Rheme, C.; Polasik, M.

    1996-01-01

    The Kβ 2 x-ray spectra of zirconium, niobium, molybdenum, and palladium bombarded by 150 and 300 keV electrons were measured with a high-resolution transmission curved crystal spectrometer. Multiconfiguration Dirac-Fock calculations were used for the decomposition of the experimental spectra into the Kβ 2 M 0 (diagram) and Kβ 2 M 1 (satellite) components. The probabilities of energy dependent (direct Coulomb and two-step) processes were estimated from the differences in the satellite line yields for electrons and photons. The satellite yields are found to be considerably enhanced in comparison with those for the proton-induced ionization recently measured and analyzed in the same way [T. Ludziejewski et al., Phys. Rev. A 52, 2791 (1995)]. This result indicates the importance of multielectron effects in the K plus M shell ionization by energetic projectiles. copyright 1996 The American Physical Society

  8. X-ray spectroscopy of a thin foil plasma produced by a short-pulse high-intensity laser

    International Nuclear Information System (INIS)

    Audebert, P.; Nagels, V.; Geindre, J.P.; Dorchies, F.; Peyrusse, O.; Gary, S.; Girard, F.; Shepherd, R.; Gauthier, J.C.; Chenais-Popovics, C.

    2003-01-01

    High density and temperature plasmas have been generated by irradiating thin foils of various elements with a high-energy subpicosecond laser pulse. The X-ray emission duration was studied by time-resolved X-ray spectroscopy. Frequency domain interferometry provided a measurement of the hydrodynamic expansion of the back of the foil as a function of time. The effect of longitudinal temperature gradients, i.e., gradients perpendicular to the surface, were decreased using very thin foil targets. Additionally, radial gradients effects, i.e., gradients parallel to the surface, were limited by using a 50 μm pinhole on target. The Al, Se and Sm spectra, recorded in the range 7.7-8 Angst. using a conical crystal spectrometer coupled to an 800 fs resolution streak camera, lasted a few picoseconds. Sm spectra showed no spectral features in this wavelength range, providing a spectrally homogeneous backlighter for future experiments. The main features of the experimental time-resolved spectra have been well reproduced with one-dimensional hydrodynamic simulations of the free expansion of a plasma heated at a given initial temperature obtained from the expansion velocity of the rear critical surface of the plasma

  9. Technology Requirements for a Square Meter, Arcsecond Resolution Telescope for X-Rays: The SMART-X Mission

    Science.gov (United States)

    Schwartz, Daniel A.; Allured, Ryan; Bookbinder, Jay A.; Cotroneo, Vincenzo; Forman, William R.; Freeman, Mark D.; McMuldroch, Stuart; Reid, Paul B.; Tananbaum, Harvey; Vikhlinin, Alexey A.; hide

    2014-01-01

    Addressing the astrophysical problems of the 2020's requires sub-arcsecond x-ray imaging with square meter effective area. Such requirements can be derived, for example, by considering deep x-ray surveys to find the young black holes in the early universe (large redshifts) which will grow into the first super-massive black holes. We have envisioned a mission, the Square Meter Arcsecond Resolution Telescope for X-rays (SMART-X), based on adjustable x-ray optics technology, incorporating mirrors with the required small ratio of mass to collecting area. We are pursuing technology which achieves sub-arcsecond resolution by on-orbit adjustment via thin film piezoelectric "cells" deposited directly on the non-reflecting sides of thin, slumped glass. While SMART-X will also incorporate state-of-the-art x-ray cameras, the remaining spacecraft systems have no requirements more stringent than those which are well understood and proven on the current Chandra X-ray Observatory.

  10. Two-energy twin image removal in atomic-resolution x-ray holography

    International Nuclear Information System (INIS)

    Nishino, Y.; Ishikawa, T.; Hayashi, K.; Takahashi, Y.; Matsubara, E.

    2002-01-01

    We propose a two-energy twin image removal algorithm for atomic-resolution x-ray holography. The validity of the algorithm is shown in a theoretical simulation and in an experiment of internal detector x-ray holography using a ZnSe single crystal. The algorithm, compared to the widely used multiple-energy algorithm, allows efficient measurement of holograms, and is especially important when the available x-ray energies are fixed. It enables twin image free holography using characteristic x rays from laboratory generators and x-ray pulses of free-electron lasers

  11. Joint European x-ray monitor (JEM-X): x-ray monitor for ESA's

    DEFF Research Database (Denmark)

    Schnopper, H.W.; Budtz-Joergensen, C.; Westergaard, Niels Jørgen Stenfeldt

    1996-01-01

    JEM-X will extend the energy range of the gamma ray instruments on ESA's INTEGRAL mission (SPI, IBIS) to include the x-ray band. JEM-X will provide images with arcminute angular resolution in the 2 - 60 keV band. The baseline photon detection system consists of two identical, high pressure, imagi...

  12. Effects of phonon broadening on x-ray near-edge spectra in molecular crystals

    Science.gov (United States)

    Vinson, John; Jach, Terrence; Elam, Tim; Denlinger, Jonathon

    2014-03-01

    Calculations of near-edge x-ray spectra are often carried out using the average atomic coordinates from x-ray or neutron scattering experiments or from density functional theory (DFT) energy minimization. This neglects disorder from thermal and zero-point vibrations. Here we look at the nitrogen K-edge of ammonium chloride and ammonium nitrate, comparing Bethe-Salpeter calculations of absorption and fluorescence to experiment. We find that intra-molecular vibrational effects lead to significant, non-uniform broadening of the spectra, and that for some features zero-point motion is the primary source of the observed shape.

  13. One dimensional detector for X-ray diffraction with superior energy resolution based on silicon strip detector technology

    International Nuclear Information System (INIS)

    Dąbrowski, W; Fiutowski, T; Wiącek, P; Fink, J; Krane, H-G

    2012-01-01

    1-D position sensitive X-ray detectors based on silicon strip detector technology have become standard instruments in X-ray diffraction and are available from several vendors. As these devices have been proven to be very useful and efficient further improvement of their performance is investigated. The silicon strip detectors in X-ray diffraction are primarily used as counting devices and the requirements concerning the spatial resolution, dynamic range and count rate capability are of primary importance. However, there are several experimental issues in which a good energy resolution is important. The energy resolution of silicon strip detectors is limited by the charge sharing effects in the sensor as well as by noise of the front-end electronics. The charge sharing effects in the sensor and various aspects of the electronics, including the baseline fluctuations, which affect the energy resolution, have been analyzed in detail and a new readout concept has been developed. A front-end ASIC with a novel scheme of baseline restoration and novel interstrip logic circuitry has been designed. The interstrip logic is used to reject the events resulting in significant charge sharing between neighboring strips. At the expense of rejecting small fraction of photons entering the detector one can obtain single strip energy spectra almost free of charge sharing effects. In the paper we present the design considerations and measured performance of the detector being developed. The electronic noise of the system at room temperature is typically of the order of 70 el rms for 17 mm long silicon strips and a peaking time of about 1 μs. The energy resolution of 600 eV FWHM has been achieved including the non-reducible charge sharing effects and the electronic noise. This energy resolution is sufficient to address a common problem in X-ray diffraction, i.e. electronic suppression of the fluorescence radiation from samples containing iron or cobalt while irradiated with 8.04 ke

  14. New set-up for high-quality soft-X-ray absorption spectroscopy of large organic molecules in the gas phase

    Energy Technology Data Exchange (ETDEWEB)

    Holch, Florian; Huebner, Dominique [Universitaet Wuerzburg, Experimentelle Physik VII, Am and Roentgen Reasearch Center for Complex Materials (RCCM) Hubland, 97074 Wuerzburg (Germany); Fink, Rainer [Universitaet Erlangen-Nuernberg, ICMM and CENEM, Egerlandstrasse 3, 91058 Erlangen (Germany); Schoell, Achim, E-mail: achim.schoell@physik.uni-wuerzburg.de [Universitaet Wuerzburg, Experimentelle Physik VII, Am and Roentgen Reasearch Center for Complex Materials (RCCM) Hubland, 97074 Wuerzburg (Germany); Umbach, Eberhard [Karlsruhe Institute of Technology, 76021 Karlsruhe (Germany)

    2011-11-15

    Highlights: {yields} We present a new set-up for x-ray absorption (NEXAFS) on large molecules in the gas-phase. {yields} The cell has a confined volume and can be heated. {yields} The spectra can be acquired fast, are of very high quality with respect tosignal-to-noise ratio and energy resolution. {yields} This allowsthe analysis of spectroscopic details (e.g. solid state effects by comparing gas- and condensed phase data). - Abstract: We present a new experimental set-up for the investigation of large (>128 amu) organic molecules in the gas-phase by means of near-edge X-ray absorption fine structure spectroscopy in the soft X-ray range. Our approach uses a gas cell, which is sealed off against the surrounding vacuum and which can be heated above the sublimation temperature of the respective molecular compound. Using a confined volume rather than a molecular beam yields short acquisition times and intense signals due to the high molecular density, which can be tuned by the container temperature. In turn, the resulting spectra are of very high quality with respect to signal-to-noise ratio and energy resolution, which are the essential aspects for the analysis of fine spectroscopic details. Using the examples of ANQ, NTCDA, and PTCDA, specific challenges of gas phase measurements on large organic molecules with high sublimation temperatures are addressed in detail with respect to the presented set-up and possible ways to tackle them are outlined.

  15. SphinX soft X-ray spectrophotometer: Science objectives, design and performance

    Science.gov (United States)

    Gburek, S.; Sylwester, J.; Kowalinski, M.; Bakala, J.; Kordylewski, Z.; Podgorski, P.; Plocieniak, S.; Siarkowski, M.; Sylwester, B.; Trzebinski, W.; Kuzin, S. V.; Pertsov, A. A.; Kotov, Yu. D.; Farnik, F.; Reale, F.; Phillips, K. J. H.

    2011-06-01

    The goals and construction details of a new design Polish-led X-ray spectrophotometer are described. The instrument is aimed to observe emission from entire solar corona and is placed as a separate block within the Russian TESIS X- and EUV complex aboard the CORONAS-PHOTON solar orbiting observatory. SphinX uses silicon PIN diode detectors for high time resolution measurements of the solar spectra in the range 0.8-15 keV. Its spectral resolution allows for discerning more than hundred separate energy bands in this range. The instrument dynamic range extends two orders of magnitude below and above these representative for GOES. The relative and absolute accuracy of spectral measurements is expected to be better than few percent, as follows from extensive ground laboratory calibrations.

  16. Experimental and Monte Carlo simulated spectra of a liquid-metal-jet x-ray source

    International Nuclear Information System (INIS)

    Marziani, M.; Gambaccini, M.; Di Domenico, G.; Taibi, A.; Cardarelli, P.

    2014-01-01

    A prototype x-ray system based on a liquid-metal-jet anode was evaluated within the framework of the LABSYNC project. The generated spectrum was measured using a CZT-based spectrometer and was compared with spectra simulated by three Monte Carlo codes: MCNPX, PENELOPE and EGS5. Notable differences in the simulated spectra were found. These are mainly attributable to differences in the models adopted for the electron-impact ionization cross section. The simulation that more closely reproduces the experimentally measured spectrum was provided by PENELOPE. - Highlights: • The x-ray spectrum of a liquid-jet x-ray anode was measured with a CZT spectrometer. • Results were compared with Monte Carlo simulations using MCNPX, PENELOPE, EGS5. • Notable differences were found among the Monte Carlo simulated spectra. • The key role was played by the electron-impact ionization cross-section model used. • The experimentally measured spectrum was closely reproduced by the PENELOPE code

  17. Spatially resolved X-ray spectra of coronal active regions

    International Nuclear Information System (INIS)

    Catura, R.C.; Acton, L.W.; Joki, E.G.; Rapley, C.G.; Culhane, J.L.

    1975-01-01

    X-ray spectra from a number of coronal active regions were obtained during ATM support rocket flights carried out by the Lockheed group on June 11 and December 19, 1973. Multi-grid collimators were used to provide fields of view of 40ins. diameter and 90ins. diameter for a number of scanning crystal spectrometers and a bent crystal spectrometer which employed a position sensitive proportional counter to register the diffracted spectrum. A solar image was produced on film and on a TV camera on board the rocket with the aid of a 1 A Hα filter. A small part of the X-ray collimator was used to generate a multiple spot diffraction pattern which was superimposed on the Hα image and the composite picture was transmitted to the ground. Pre-launch calibrations allowed the spot corresponding to the X-ray collimator axis to be identified and so the collimator pointing direction on the solar disc was controlled from the ground by means of commands sent to the rocket. (Auth.)

  18. The X-ray spectra of clusters of galaxies and their relationship to other cluster properties

    International Nuclear Information System (INIS)

    Mitchell, R.J.; Dickens, R.J.; Burnell, S.J.B.; Culhane, J.L.

    1979-01-01

    New observations with the MSSL proportional counter spectrometer on the Ariel V satellite of the X-ray spectra of 20 candidate clusters of galaxies are reported. The data are compared with the results from the OSO-8 satellite and the combined sample of some 30 cluster X-ray spectra are analysed. The present study finds generally larger values of Lsub(X) than do Uhuru or the SSI, which, because of the larger field of view, may indicate significant amounts of hot gas away from the cluster centres. The validity of all X-ray cluster identifications has been examined, and sources have been classified according to certainty of identification. The incidence of X-ray line emission from the clusters has been investigated and temperatures, kTsub(X), have been derived on the basis of an isothermal model. Relationships between X-ray, optical and radio properties of the clusters have been studied. The more massive, centrally condensed clusters generally contain higher temperature gas and have a greater luminosity than the less massive, more irregular clusters. (author)

  19. A short working distance multiple crystal x-ray spectrometer

    Science.gov (United States)

    Dickinson, B.; Seidler, G.T.; Webb, Z.W.; Bradley, J.A.; Nagle, K.P.; Heald, S.M.; Gordon, R.A.; Chou, I.-Ming

    2008-01-01

    For x-ray spot sizes of a few tens of microns or smaller, a millimeter-sized flat analyzer crystal placed ???1 cm from the sample will exhibit high energy resolution while subtending a collection solid angle comparable to that of a typical spherically bent crystal analyzer (SBCA) at much larger working distances. Based on this observation and a nonfocusing geometry for the analyzer optic, we have constructed and tested a short working distance (SWD) multicrystal x-ray spectrometer. This prototype instrument has a maximum effective collection solid angle of 0.14 sr, comparable to that of 17 SBCA at 1 m working distance. We find good agreement with prior work for measurements of the Mn K?? x-ray emission and resonant inelastic x-ray scattering for MnO, and also for measurements of the x-ray absorption near-edge structure for Dy metal using L??2 partial-fluorescence yield detection. We discuss future applications at third- and fourth-generation light sources. For concentrated samples, the extremely large collection angle of SWD spectrometers will permit collection of high-resolution x-ray emission spectra with a single pulse of the Linac Coherent Light Source. The range of applications of SWD spectrometers and traditional multi-SBCA instruments has some overlap, but also is significantly complementary. ?? 2008 American Institute of Physics.

  20. Small-angle scattering of polychromatic X-rays: effects of bandwidth, spectral shape and high harmonics

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Sen; Luo, Sheng-Nian

    2018-02-16

    Polychromatic X-ray sources can be useful for photon-starved small-angle X-ray scattering given their high spectral fluxes. Their bandwidths, however, are 10–100 times larger than those using monochromators. To explore the feasibility, ideal scattering curves of homogeneous spherical particles for polychromatic X-rays are calculated and analyzed using the Guinier approach, maximum entropy and regularization methods. Monodisperse and polydisperse systems are explored. The influence of bandwidth and asymmetric spectra shape are exploredviaGaussian and half-Gaussian spectra. Synchrotron undulator spectra represented by two undulator sources of the Advanced Photon Source are examined as an example, as regards the influence of asymmetric harmonic shape, fundamental harmonic bandwidth and high harmonics. The effects of bandwidth, spectral shape and high harmonics on particle size determination are evaluated quantitatively.

  1. Small-angle scattering of polychromatic X-rays: effects of bandwidth, spectral shape and high harmonics.

    Science.gov (United States)

    Chen, Sen; Luo, Sheng Nian

    2018-03-01

    Polychromatic X-ray sources can be useful for photon-starved small-angle X-ray scattering given their high spectral fluxes. Their bandwidths, however, are 10-100 times larger than those using monochromators. To explore the feasibility, ideal scattering curves of homogeneous spherical particles for polychromatic X-rays are calculated and analyzed using the Guinier approach, maximum entropy and regularization methods. Monodisperse and polydisperse systems are explored. The influence of bandwidth and asymmetric spectra shape are explored via Gaussian and half-Gaussian spectra. Synchrotron undulator spectra represented by two undulator sources of the Advanced Photon Source are examined as an example, as regards the influence of asymmetric harmonic shape, fundamental harmonic bandwidth and high harmonics. The effects of bandwidth, spectral shape and high harmonics on particle size determination are evaluated quantitatively.

  2. Development of X-ray excitable luminescent probes for scanning X-ray microscopy

    International Nuclear Information System (INIS)

    Moronne, M.M.

    1999-01-01

    Transmission soft X-ray microscopy is now capable of achieving resolutions that are typically 5 times better than the best-visible light microscopes. With expected improvements in zone plate optics, an additional factor of two may be realized within the next few years. Despite the high resolution now available with X-ray microscopes and the high X-ray contrast provided by biological molecules in the soft X-ray region (λ=2-5 nm), molecular probes for localizing specific biological targets have been lacking. To circumvent this problem, X-ray excitable molecular probes are needed that can target unique biological features. In this paper we report our initial results on the development of lanthanide-based fluorescent probes for biological labeling. Using scanning luminescence X-ray microscopy (SLXM, Jacobsen et al., J. Microscopy 172 (1993) 121-129), we show that lanthanide organo-polychelate complexes are sufficiently bright and radiation resistant to be the basis of a new class of X-ray excitable molecular probes capable of providing at least a fivefold improvement in resolution over visible light microscopy. Lanthanide probes, able to bind 80-100 metal ions per molecule, were found to give strong luminescent signals with X-ray doses exceeding 10 8 Gy, and were used to label actin stress fibers and in vitro preparations of polymerized tubulin. (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

  3. Searches for hard X-ray gamma-ray burst afterglows with the BAT on Swift

    International Nuclear Information System (INIS)

    Krimm, Hans A.; Ozawa, Hideki; Weidenspointner, Georg; Barbier, Louis M.; Barthelmy, Scott D.; Gehrels, Neil; Parsons, Ann M.; Tueller, Jack; Eftekharzadeh, Ardeshir; Hullinger, Derek D.; Markwardt, Craig; Fenimore, Edward E.; Palmer, David M.

    2003-01-01

    The Burst Alert Telescope (BAT) on the Swift gamma ray burst mission will continue to observe the fields of all detected gamma-ray bursts for several days after the prompt emission has faded. Utilizing first event-by-event data, then one minute and later five minute survey accumulations, the BAT will be extremely sensitive to the hard X-ray afterglow known to be associated with many bursts. This data will cover the crucial transition of the afterglow from rapid variability to the smoothly decaying power law in time and will extend observations of the tails of individual bursts to longer time scales than have been achievable so far. Since Swift is sensitive to short duration GRBs, we will also be able to determine whether hard X-ray afterglows are associated with short GRBs. The BAT will provide high resolution spectra of burst afterglows, allowing us to study in detail the time evolution of GRB spectra

  4. High spectral resolution studies of gamma ray bursts on new missions

    International Nuclear Information System (INIS)

    Desai, U. D.; Acuna, M. H.; Cline, T. L.; Dennis, B. R.; Orwig, L. E.; Trombka, J. I.; Starr, R. D.

    1996-01-01

    Two new missions will be launched in 1996 and 1997, each carrying X-ray and gamma ray detectors capable of high spectral resolution at room temperature. The Argentine Satelite de Aplicaciones Cientificas (SAC-B) and the Small Spacecraft Technology Initiative (SSTI) Clark missions will each carry several arrays of X-ray detectors primarily intended for the study of solar flares and gamma-ray bursts. Arrays of small (1 cm 2 ) cadmium zinc telluride (CZT) units will provide x-ray measurements in the 10 to 80 keV range with an energy resolution of ≅6 keV. Arrays of both silicon avalanche photodiodes (APD) and P-intrinsic-N (PIN) photodiodes (for the SAC-B mission only) will provide energy coverage from 2-25 keV with ≅1 keV resolution. For SAC-B, higher energy spectral data covering the 30-300 keV energy range will be provided by CsI(Tl) scintillators coupled to silicon APDs, resulting in similar resolution but greater simplicity relative to conventional CsI/PMT systems. Because of problems with the Pegasus launch vehicle, the launch of SAC-B has been delayed until 1997. The launch of the SSTI Clark mission is scheduled for June 1996

  5. X-ray stars observed in LAMOST spectral survey

    Science.gov (United States)

    Lu, Hong-peng; Zhang, Li-yun; Han, Xianming L.; Shi, Jianrong

    2018-05-01

    X-ray stars have been studied since the beginning of X-ray astronomy. Investigating and studying the chromospheric activity from X-ray stellar optical spectra is highly significant in providing insights into stellar magnetic activity. The big data of LAMOST survey provides an opportunity for researching stellar optical spectroscopic properties of X-ray stars. We inferred the physical properties of X-ray stellar sources from the analysis of LAMOST spectra. First, we cross-matched the X-ray stellar catalogue (12254 X-ray stars) from ARXA with LAMOST data release 3 (DR3), and obtained 984 good spectra from 713 X-ray sources. We then visually inspected and assigned spectral type to each spectrum and calculated the equivalent width (EW) of Hα line using the Hammer spectral typing facility. Based on the EW of Hα line, we found 203 spectra of 145 X-ray sources with Hα emission above the continuum. For these spectra we also measured the EWs of Hβ, Hγ, Hδ and Ca ii IRT lines of these spectra. After removing novae, planetary nebulae and OB-type stars, we found there are 127 X-ray late-type stars with Hα line emission. By using our spectra and results from the literature, we found 53 X-ray stars showing Hα variability; these objects are Classical T Tauri stars (CTTs), cataclysmic variables (CVs) or chromospheric activity stars. We also found 18 X-ray stars showing obvious emissions in the Ca ii IRT lines. Of the 18 X-ray stars, 16 are CTTs and 2 are CVs. Finally, we discussed the relationships between the EW of Hα line and X-ray flux.

  6. 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.

  7. xMDFF: molecular dynamics flexible fitting of low-resolution X-ray structures.

    Science.gov (United States)

    McGreevy, Ryan; Singharoy, Abhishek; Li, Qufei; Zhang, Jingfen; Xu, Dong; Perozo, Eduardo; Schulten, Klaus

    2014-09-01

    X-ray crystallography remains the most dominant method for solving atomic structures. However, for relatively large systems, the availability of only medium-to-low-resolution diffraction data often limits the determination of all-atom details. A new molecular dynamics flexible fitting (MDFF)-based approach, xMDFF, for determining structures from such low-resolution crystallographic data is reported. xMDFF employs a real-space refinement scheme that flexibly fits atomic models into an iteratively updating electron-density map. It addresses significant large-scale deformations of the initial model to fit the low-resolution density, as tested with synthetic low-resolution maps of D-ribose-binding protein. xMDFF has been successfully applied to re-refine six low-resolution protein structures of varying sizes that had already been submitted to the Protein Data Bank. Finally, via systematic refinement of a series of data from 3.6 to 7 Å resolution, xMDFF refinements together with electrophysiology experiments were used to validate the first all-atom structure of the voltage-sensing protein Ci-VSP.

  8. Dispersive x-ray synchrotron studies of Pt-C multilayers

    International Nuclear Information System (INIS)

    Smither, R.K.; Rodricks, B.; Lamelas, F.; Medjahed, D.; Dos Passos, W.; Clarke, R.; Ziegler, E.; Fontaine, A.

    1989-02-01

    We demonstrate the simultaneous acquisition of high-resolution x-ray absorption spectra and scattering data, using a combination of energy-dispersive optics and a two-dimensional CCD detector. Results are presented on the optical constants of Pt and on the reflectivity of a platinum-carbon multilayer at the L/sub III/ absorption edge of Pt. 12 refs., 5 figs

  9. Use of an iterative convolution approach for qualitative and quantitative peak analysis in low resolution gamma-ray spectra

    International Nuclear Information System (INIS)

    Gardner, Robin P.; Ai Xianyun; Peeples, Cody R.; Wang, Jiaxin; Lee, Kyoung; Peeples, Johanna L.; Calderon, Adan

    2011-01-01

    In many applications, low resolution gamma-ray spectrometers, such as sodium iodide scintillation detectors, are widely used primarily due to their relatively low cost and high detection efficiency. There is widespread interest in improved methods for analyzing spectral data acquired with such devices, using inverse analysis. Peak means and peak areas in gamma- and X-ray spectra are needed for both qualitative and quantitative analysis. This paper introduces the PEAKSI code package that was developed at the Center for Engineering Applications of Radioisotopes (CEAR). The basic approach described here is to use accurate forward models and iterative convolution instead of direct deconvolution. Rather than smoothing and differentiation a combination of linear regression and non-linear searching is used to minimize the reduced chi-square, since this approach retains the capability of establishing uncertainties in the estimated peak parameters. The PEAKSI package uses a Levenberg-Marquardt (LM) non-linear search method combined with multiple linear regression (MLR) to minimize the reduced chi-square value for fitting single or multiple overlapping peaks to determine peak parameters, including peak means, peak standard deviations or full width at half maximum (FWHM), net peak counts, and background counts of peaks in experimental gamma-ray spectra. This approach maintains the natural error structure so that parameter uncertainties can be estimated. The plan is to release this code to the public in the near future.

  10. EMISSION LINES BETWEEN 1 AND 2 keV IN COMETARY X-RAY SPECTRA

    Energy Technology Data Exchange (ETDEWEB)

    Ewing, Ian; Christian, Damian J. [Department of Physics and Astronomy, California State University, 18111 Nordhoff Street, Northridge, CA 91330 (United States); Bodewits, Dennis [Department of Astronomy, University of Maryland, College Park, MD 20742 (United States); Dennerl, Konrad [Max-Planck-Institut fuer extraterrestrische Physik, Postfach 1312, D-85741 Garching Germany (Germany); Lisse, Carey M. [Planetary Exploration Group, Space Department, Johns Hopkins University Applied Physics Laboratory, 11100 Johns Hopkins Rd, Laurel, MD 20723 (United States); Wolk, Scott J., E-mail: ian.ewing.794@my.csun.edu, E-mail: daman.christian@csun.edu [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)

    2013-01-20

    We present the detection of new cometary X-ray emission lines in the 1.0-2.0 keV range using a sample of comets observed with the Chandra X-Ray Observatory and ACIS spectrometer. We have selected five comets from the Chandra sample with good signal-to-noise spectra. The surveyed comets are C/1999 S4 (LINEAR), C/1999 T1 (McNaught-Hartley), 153P/2002 (Ikeya-Zhang), 2P/2003 (Encke), and C/2008 8P (Tuttle). We modeled the spectra with an extended version of our solar wind charge exchange (SWCX) emission model. Above 1 keV, we find Ikeya-Zhang to have strong emission lines at 1340 and 1850 eV which we identify as being created by SWCX lines of Mg XI and Si XIII, respectively, and weaker emission lines at 1470, 1600, and 1950 eV formed by SWCX of Mg XII, Mg XI, and Si XIV, respectively. The Mg XI and XII and Si XIII and XIV lines are detected at a significant level for the other comets in our sample (LS4, MH, Encke, 8P), and these lines promise additional diagnostics to be included in SWCX models. The silicon lines in the 1700-2000 eV range are detected for all comets, but with the rising background and decreasing cometary emission, we caution that these detections need further confirmation with higher resolution instruments.

  11. The Athena X-ray Integral Field Unit (X-IFU)

    NARCIS (Netherlands)

    Barret, Didier; Lam Trong, Thien; den Herder, Jan-Willem; Piro, Luigi; Barcons, Xavier; Huovelin, Juhani; Kelley, Richard; Mas-Hesse, J. Miguel; Mitsuda, Kazuhisa; Paltani, Stéphane; Rauw, Gregor; RoŻanska, Agata; Wilms, Joern; Barbera, Marco; Bozzo, Enrico; Ceballos, Maria Teresa; Charles, Ivan; Decourchelle, Anne; den Hartog, Roland; Duval, Jean-Marc; Fiore, Fabrizio; Gatti, Flavio; Goldwurm, Andrea; Jackson, Brian; Jonker, Peter; Kilbourne, Caroline; Macculi, Claudio; Mendez, Mariano; Molendi, Silvano; Orleanski, Piotr; Pajot, François; Pointecouteau, Etienne; Porter, Frederick; Pratt, Gabriel W.; Prêle, Damien; Ravera, Laurent; Renotte, Etienne; Schaye, Joop; Shinozaki, Keisuke; Valenziano, Luca; Vink, Jacco; Webb, Natalie; Yamasaki, Noriko; Delcelier-Douchin, Françoise; Le Du, Michel; Mesnager, Jean-Michel; Pradines, Alice; Branduardi-Raymont, Graziella; Dadina, Mauro; Finoguenov, Alexis; Fukazawa, Yasushi; Janiuk, Agnieszka; Miller, Jon; Nazé, Yaël; Nicastro, Fabrizio; Sciortino, Salvatore; Torrejon, Jose Miguel; Geoffray, Hervé; Hernandez, Isabelle; Luno, Laure; Peille, Philippe; André, Jérôme; Daniel, Christophe; Etcheverry, Christophe; Gloaguen, Emilie; Hassin, Jérémie; Hervet, Gilles; Maussang, Irwin; Moueza, Jérôme; Paillet, Alexis; Vella, Bruno; Campos Garrido, Gonzalo; Damery, Jean-Charles; Panem, Chantal; Panh, Johan; Bandler, Simon; Biffi, Jean-Marc; Boyce, Kevin; Clénet, Antoine; DiPirro, Michael; Jamotton, Pierre; Lotti, Simone; Schwander, Denis; Smith, Stephen; van Leeuwen, Bert-Joost; van Weers, Henk; Brand, Thorsten; Cobo, Beatriz; Dauser, Thomas; de Plaa, Jelle; Cucchetti, Edoardo

    2016-01-01

    The X-ray Integral Field Unit (X-IFU) on board the Advanced Telescope for High-ENergy Astrophysics (Athena) will provide spatially resolved high-resolution X-ray spectroscopy from 0.2 to 12 keV, with 5" pixels over a field of view of 5 arc minute equivalent diameter and a spectral resolution of 2.5

  12. 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

  13. X-Ray Observations of High-Energy Pulsars: PSR B1951+32 and Geminga

    Science.gov (United States)

    Ho, Cheng

    Observations at frequencies across a wide range of electromagnetic spectra are key to the understanding of the origin and mechanisms of high-energy emissions from pulsars. We propose to observe the high-energy pulsars PSR B1951+32 and Geminga with XTE. These two sources emit X-rays at low enough count rate that we can acquire high resolution timing and spectral data, allowing us to perform detailed analysis on the ground. Staring integration of 10 ksec for each source is requested. Data obtained in these observations, together with those from ROSAT, GRO and a planned project for optical counterpart study at Los Alamos, will provide crucial information to advance high-energy pulsar research.

  14. Characterization of LiF-based soft X-ray imaging detectors by confocal fluorescence microscopy

    International Nuclear Information System (INIS)

    Bonfigli, F; Gaudio, P; Lupelli, I; Nichelatti, E; Richetta, M; Vincenti, M A; Montereali, R M

    2010-01-01

    X-ray microscopy represents a powerful tool to obtain images of samples with very high spatial resolution. The main limitation of this technique is represented by the poor spatial resolution of standard imaging detectors. We proposed an innovative high-performance X-ray imaging detector based on the visible photoluminescence of colour centres in lithium fluoride. In this work, a confocal microscope in fluorescence mode was used to characterize LiF-based imaging detectors measuring CC integrated visible fluorescence signals of LiF crystals and films (grown on several kinds of substrates) irradiated by soft X-rays produced by a laser plasma source in different exposure conditions. The results are compared with the CC photoluminescence spectra measured on the same samples and discussed.

  15. Spectroscopic investigations of hard x-ray emission from 120 ps laser-produced plasmas at intensities near 1017 W cm-2

    International Nuclear Information System (INIS)

    Dunn, J.; Young, B.K.F.; Osterheld, A.L.; Foord, M.E.; Walling, R.S.; Stewart, R.E.; Faenov, A.Y.

    1995-11-01

    Spectroscopic investigations of the x-ray emission of plasmas heated by 120 ps, frequency doubled pulses from the JANUS Nd: glass laser are presented. High Z K-shell spectra emitted from slab targets heated to near 10 17 W cm -2 intensity are investigated. High resolution (γ/Δγ>5000) x-ray spectra of multicharged ions of H-like Ti, Co, Ni, Cu, and also H-like Sc in the spectral range 1.5--3.0 angstrom are obtained in single laser shots using a spherically bent Mica crystal spectrograph with a 186 mm radius of curvature. The spectra- have one dimensional spatial resolution of about 25μm and indicate that the size of the emission zone of the resonance, transitions is 2 keV and density∼10 22 cm -3 . These experiments demonstrate that with modest laser energy, plasmas heated by high-intensity 120 ps lasers provide a very bright source of hard ∼8 keV x-ray emission

  16. Comparison of hard X-ray spectra obtained by spectrometers on Hinotori and SMM and detection of 'superhot' component

    Science.gov (United States)

    Nitta, Nariaki

    1988-01-01

    Hard X-ray spectra in solar flares obtained by the broadband spectrometers aboard Hinotori and SMM are compared. Within the uncertainty brought about by assuming the typical energy of the background X-rays, spectra by the Hinotori spectrometer are usually consistent with those by the SMM spectrometer for flares in 1981. On the contrary, flares in 1982 persistently show 20-50-percent higher flux by Hinotori than by SMM. If this discrepancy is entirely attributable to errors in the calibration of energy ranges, the errors would be about 10 percent. Despite such a discrepancy in absolute flux, in the the decay phase of one flare, spectra revealed a hard X-ray component (probably a 'superhot' component) that could be explained neither by emission from a plasma at about 2 x 10 to the 7th K nor by a nonthermal power-law component. Imaging observations during this period show hard X-ray emission nearly cospatial with soft X-ray emission, in contrast with earlier times at which hard and soft X-rays come from different places.

  17. Soft X-ray radiation damage in EM-CCDs used for Resonant Inelastic X-ray Scattering

    Science.gov (United States)

    Gopinath, D.; Soman, M.; Holland, A.; Keelan, J.; Hall, D.; Holland, K.; Colebrook, D.

    2018-02-01

    Advancement in synchrotron and free electron laser facilities means that X-ray beams with higher intensity than ever before are being created. The high brilliance of the X-ray beam, as well as the ability to use a range of X-ray energies, means that they can be used in a wide range of applications. One such application is Resonant Inelastic X-ray Scattering (RIXS). RIXS uses the intense and tuneable X-ray beams in order to investigate the electronic structure of materials. The photons are focused onto a sample material and the scattered X-ray beam is diffracted off a high resolution grating to disperse the X-ray energies onto a position sensitive detector. Whilst several factors affect the total system energy resolution, the performance of RIXS experiments can be limited by the spatial resolution of the detector used. Electron-Multiplying CCDs (EM-CCDs) at high gain in combination with centroiding of the photon charge cloud across several detector pixels can lead to sub-pixel spatial resolution of 2-3 μm. X-ray radiation can cause damage to CCDs through ionisation damage resulting in increases in dark current and/or a shift in flat band voltage. Understanding the effect of radiation damage on EM-CCDs is important in order to predict lifetime as well as the change in performance over time. Two CCD-97s were taken to PTB at BESSY II and irradiated with large doses of soft X-rays in order to probe the front and back surfaces of the device. The dark current was shown to decay over time with two different exponential components to it. This paper will discuss the use of EM-CCDs for readout of RIXS spectrometers, and limitations on spatial resolution, together with any limitations on instrument use which may arise from X-ray-induced radiation damage.

  18. High-intensity x-ray holography: an approach to high-resolution snapshot imaging of biological specimens

    International Nuclear Information System (INIS)

    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

  19. 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.

  20. 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...

  1. Absorption spectra response of XRQA radiochromic film to x-ray radiation

    International Nuclear Information System (INIS)

    Alnawaf, Hani; Cheung, Tsang; Butson, Martin J.; Yu, Peter K.N.

    2010-01-01

    Gafchromic XRQA, radiochromic film is a high sensitivity auto developing x-ray analysis films designed and available for kilovoltage x-ray, dose and QA assessment applications. The film is designed for reflective analysis with a yellow transparent top filter and white opaque backing materials. This allows the film to be visually inspected for colour changes with a higher level of contrast than clear coated radiochromic films such as Gafchromic EBT version 1. The spectral absorption properties in the visible wavelengths have been investigated and results show two main peaks in absorption located at 636 nm and 585 nm. These peaks are located in the same position as EBT Gafchromic film highlighting a similar chemical monomer/polymer for radiation sensitivity. A much higher sensitivity however is found at kilovoltage energies with an average 1.55 OD units per 20 cGy irradiation variation measured at 636 nm using 150 kVp x-rays. This is compared to approximately 0.12 OD units per 20 cGy measured at 636 nm for EBT film at 6 MV x-ray energy. That is, the XRQA film is more than 10 times more sensitive than EBT1 film. The visual colour change is enhanced by the yellow polyester coating. However this does not affect the absorption spectra properties in the red region of analysis which is the main area for use using desktop scanners in reflection mode.

  2. High spatial resolution grain orientation and strain mapping in thin films using polychromatic submicron x-ray diffraction

    Science.gov (United States)

    Tamura, N.; MacDowell, A. A.; Celestre, R. S.; Padmore, H. A.; Valek, B.; Bravman, J. C.; Spolenak, R.; Brown, W. L.; Marieb, T.; Fujimoto, H.; Batterman, B. W.; Patel, J. R.

    2002-05-01

    The availability of high brilliance synchrotron sources, coupled with recent progress in achromatic focusing optics and large area two-dimensional detector technology, has allowed us to develop an x-ray synchrotron technique that is 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 levels. Due 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.

  3. A theoretical and experimental evaluation of the microangiographic fluoroscope: A high-resolution region-of-interest x-ray imager

    International Nuclear Information System (INIS)

    Jain, Amit; Bednarek, D. R.; Ionita, Ciprian; Rudin, S.

    2011-01-01

    Purpose: The increasing need for better image quality and high spatial resolution for successful endovascular image-guided interventions (EIGIs) and the inherent limitations of the state-of-the-art detectors provide motivation to develop a detector system tailored to the specific, demanding requirements of neurointerventional applications.Method: A microangiographic fluoroscope (MAF) was developed to serve as a high-resolution, region-of-interest (ROI) x-ray imaging detector in conjunction with large lower-resolution full field-of-view (FOV) state-of-the-art x-ray detectors. The newly developed MAF is an indirect x-ray imaging detector capable of providing real-time images (30 frames per second) with high-resolution, high sensitivity, no lag and low instrumentation noise. It consists of a CCD camera coupled to a Gen 2 dual-stage microchannel plate light image intensifier (LII) through a fiber-optic taper. A 300 μm thick CsI(Tl) phosphor serving as the front end is coupled to the LII. The LII is the key component of the MAF and the large variable gain provided by it enables the MAF to operate as a quantum-noise-limited detector for both fluoroscopy and angiography. Results: The linear cascade model was used to predict the theoretical performance of the MAF, and the theoretical prediction showed close agreement with experimental findings. Linear system metrics such as MTF and DQE were used to gauge the detector performance up to 10 cycles/mm. The measured zero frequency DQE(0) was 0.55 for an RQA5 spectrum. A total of 21 stages were identified for the whole imaging chain and each stage was characterized individually. Conclusions: The linear cascade model analysis provides insight into the imaging chain and may be useful for further development of the MAF detector. The preclinical testing of the prototype detector in animal procedures is showing encouraging results and points to the potential for significant impact on EIGIs when used in conjunction with a state

  4. X-ray Spectroscopy of Hot Dense Plasmas: Experimental Limits, Line Shifts and Field Effects

    International Nuclear Information System (INIS)

    Renner, Oldrich; Sauvan, Patrick; Dalimier, Elisabeth; Riconda, Caterina; Rosmej, Frank B.; Weber, Stefan; Nicolai, Philippe; Peyrusse, Olivier; Uschmann, Ingo; Hoefer, Sebastian; Kaempfer, Tino; Loetzsch, Robert; Zastrau, Ulf; Foerster, Eckhart; Oks, Eugene

    2008-01-01

    High-resolution x-ray spectroscopy is capable of providing complex information on environmental conditions in hot dense plasmas. Benefiting from application of modern spectroscopic methods, we report experiments aiming at identification of different phenomena occurring in laser-produced plasma. Fine features observed in broadened profiles of the emitted x-ray lines and their satellites are interpreted using theoretical models predicting spectra modification under diverse experimental situations.

  5. X-ray Optics Development at MSFC

    Science.gov (United States)

    Sharma, Dharma P.

    2017-01-01

    Development of high resolution focusing telescopes has led to a tremendous leap in sensitivity, revolutionizing observational X-ray astronomy. High sensitivity and high spatial resolution X-ray observations have been possible due to use of grazing incidence optics (paraboloid/hyperboloid) coupled with high spatial resolution and high efficiency detectors/imagers. The best X-ray telescope flown so far is mounted onboard Chandra observatory launched on July 23,1999. The telescope has a spatial resolution of 0.5 arc seconds with compatible imaging instruments in the energy range of 0.1 to 10 keV. The Chandra observatory has been responsible for a large number of discoveries and has provided X-ray insights on a large number of celestial objects including stars, supernova remnants, pulsars, magnetars, black holes, active galactic nuclei, galaxies, clusters and our own solar system.

  6. Understanding reliability and some limitations of the images and spectra reconstructed from a multi-monochromatic x-ray imager

    Science.gov (United States)

    Nagayama, T.; Mancini, R. C.; Mayes, D.; Tommasini, R.; Florido, R.

    2015-11-01

    Temperature and density asymmetry diagnosis is critical to advance inertial confinement fusion (ICF) science. A multi-monochromatic x-ray imager (MMI) is an attractive diagnostic for this purpose. The MMI records the spectral signature from an ICF implosion core with time resolution, 2-D space resolution, and spectral resolution. While narrow-band images and 2-D space-resolved spectra from the MMI data constrain temperature and density spatial structure of the core, the accuracy of the images and spectra depends not only on the quality of the MMI data but also on the reliability of the post-processing tools. Here, we synthetically quantify the accuracy of images and spectra reconstructed from MMI data. Errors in the reconstructed images are less than a few percent when the space-resolution effect is applied to the modeled images. The errors in the reconstructed 2-D space-resolved spectra are also less than a few percent except those for the peripheral regions. Spectra reconstructed for the peripheral regions have slightly but systematically lower intensities by ˜6% due to the instrumental spatial-resolution effects. However, this does not alter the relative line ratios and widths and thus does not affect the temperature and density diagnostics. We also investigate the impact of the pinhole size variation on the extracted images and spectra. A 10% pinhole size variation could introduce spatial bias to the images and spectra of ˜10%. A correction algorithm is developed, and it successfully reduces the errors to a few percent. It is desirable to perform similar synthetic investigations to fully understand the reliability and limitations of each MMI application.

  7. Understanding reliability and some limitations of the images and spectra reconstructed from a multi-monochromatic x-ray imager

    International Nuclear Information System (INIS)

    Nagayama, T.; Mancini, R. C.; Mayes, D.; Tommasini, R.; Florido, R.

    2015-01-01

    Temperature and density asymmetry diagnosis is critical to advance inertial confinement fusion (ICF) science. A multi-monochromatic x-ray imager (MMI) is an attractive diagnostic for this purpose. The MMI records the spectral signature from an ICF implosion core with time resolution, 2-D space resolution, and spectral resolution. While narrow-band images and 2-D space-resolved spectra from the MMI data constrain temperature and density spatial structure of the core, the accuracy of the images and spectra depends not only on the quality of the MMI data but also on the reliability of the post-processing tools. Here, we synthetically quantify the accuracy of images and spectra reconstructed from MMI data. Errors in the reconstructed images are less than a few percent when the space-resolution effect is applied to the modeled images. The errors in the reconstructed 2-D space-resolved spectra are also less than a few percent except those for the peripheral regions. Spectra reconstructed for the peripheral regions have slightly but systematically lower intensities by ∼6% due to the instrumental spatial-resolution effects. However, this does not alter the relative line ratios and widths and thus does not affect the temperature and density diagnostics. We also investigate the impact of the pinhole size variation on the extracted images and spectra. A 10% pinhole size variation could introduce spatial bias to the images and spectra of ∼10%. A correction algorithm is developed, and it successfully reduces the errors to a few percent. It is desirable to perform similar synthetic investigations to fully understand the reliability and limitations of each MMI application

  8. Understanding reliability and some limitations of the images and spectra reconstructed from a multi-monochromatic x-ray imager.

    Science.gov (United States)

    Nagayama, T; Mancini, R C; Mayes, D; Tommasini, R; Florido, R

    2015-11-01

    Temperature and density asymmetry diagnosis is critical to advance inertial confinement fusion (ICF) science. A multi-monochromatic x-ray imager (MMI) is an attractive diagnostic for this purpose. The MMI records the spectral signature from an ICF implosion core with time resolution, 2-D space resolution, and spectral resolution. While narrow-band images and 2-D space-resolved spectra from the MMI data constrain temperature and density spatial structure of the core, the accuracy of the images and spectra depends not only on the quality of the MMI data but also on the reliability of the post-processing tools. Here, we synthetically quantify the accuracy of images and spectra reconstructed from MMI data. Errors in the reconstructed images are less than a few percent when the space-resolution effect is applied to the modeled images. The errors in the reconstructed 2-D space-resolved spectra are also less than a few percent except those for the peripheral regions. Spectra reconstructed for the peripheral regions have slightly but systematically lower intensities by ∼6% due to the instrumental spatial-resolution effects. However, this does not alter the relative line ratios and widths and thus does not affect the temperature and density diagnostics. We also investigate the impact of the pinhole size variation on the extracted images and spectra. A 10% pinhole size variation could introduce spatial bias to the images and spectra of ∼10%. A correction algorithm is developed, and it successfully reduces the errors to a few percent. It is desirable to perform similar synthetic investigations to fully understand the reliability and limitations of each MMI application.

  9. Research and Development of a portable microfocus x-ray system capable of providing ultra-high resolutions images of improvised explosive devices

    International Nuclear Information System (INIS)

    Korkala, G.

    1989-01-01

    The utilization of x-ray screening has long been a recognized valuable tool as a means to evaluate and identify suspect articles for possible improvised explosive devices. Recent bombings indicate an increase in technical sophistication by the terrorist which demand additional means to further the possibility of detecting these devices before they reach their target or detonate. This paper discusses history of the use of x-ray and the design parameters of a portable micro-focus x-ray system capable of providing ultra high resolution radiographs as well as being able to be used with additional state-of-the-art imaging systems

  10. Soft X-ray scanning transmission X-ray microscopy (STXM) of actinide particles.

    Science.gov (United States)

    Nilsson, Hans J; Tyliszczak, Tolek; Wilson, Richard E; Werme, Lars; Shuh, David K

    2005-09-01

    A descriptive account is given of our most recent research on the actinide dioxides with the Advanced Light Source Molecular Environmental Science (ALS-MES) Beamline 11.0.2 soft X-ray scanning transmission X-ray microscope (STXM) at the Lawrence Berkeley National Laboratory (LBNL). The ALS-MES STXM permits near-edge X-ray absorption fine structure (NEXAFS) and imaging with 30-nm spatial resolution. The first STXM spectromicroscopy NEXAFS spectra at the actinide 4d5/2 edges of the imaged transuranic particles, NpO2 and PuO2, have been obtained. Radiation damage induced by the STXM was observed in the investigation of a mixed oxidation state particle (Np(V,VI)) and was minimized during collection of the actual spectra at the 4d5/2 edge of the Np(V,VI) solid. A plutonium elemental map was obtained from an irregular PuO2 particle with the dimensions of 650 x 650 nm. The Pu 4d5/2 NEXAFS spectra were collected at several different locations from the PuO2 particle and were identical. A representative oxygen K-edge spectrum from UO2 was collected and resembles the oxygen K-edge from the bulk material. The unique and current performance of the ALS-MES STXM at extremely low energies (ca. 100 eV) that may permit the successful measurement of the actinide 5d edge is documented. Finally, the potential of STXM as a tool for actinide investigations is briefly discussed.

  11. In-phantom spectrometry of medical diagnostic x rays

    International Nuclear Information System (INIS)

    Stansbury, P.S.

    1977-10-01

    A program of measurements was made to determine the spectral fluence distributions at locations of significance in a heterogeneous, hominoid phantom exposed to x rays in a manner simulating medical diagnostic radiology. The measurements were made with a specially constructed NaI(Tl) scintillation detector. The detector had a spherically shaped active volume 0.6 cm in diameter. The resolution of this detector was five times worse than that of a more conventional NaI(Tl) spectrometer. Resolution broadening and other distortions were removed from the observed pulse height spectra with a computer-coded, iterative unfolding technique. The performance of the spectrometer and the unfolding scheme was assessed by comparing, in a few cases, the unfolded NaI(Tl) spectra with spectra determined with a high resolution Ge(Li) spectrometer. The measurements were made in a physical model of an idealized representation of an average adult patient

  12. In-phantom spectrometry of medical diagnostic x rays

    Energy Technology Data Exchange (ETDEWEB)

    Stansbury, P. S.

    1977-10-01

    A program of measurements was made to determine the spectral fluence distributions at locations of significance in a heterogeneous, hominoid phantom exposed to x rays in a manner simulating medical diagnostic radiology. The measurements were made with a specially constructed NaI(Tl) scintillation detector. The detector had a spherically shaped active volume 0.6 cm in diameter. The resolution of this detector was five times worse than that of a more conventional NaI(Tl) spectrometer. Resolution broadening and other distortions were removed from the observed pulse height spectra with a computer-coded, iterative unfolding technique. The performance of the spectrometer and the unfolding scheme was assessed by comparing, in a few cases, the unfolded NaI(Tl) spectra with spectra determined with a high resolution Ge(Li) spectrometer. The measurements were made in a physical model of an idealized representation of an average adult patient.

  13. TU-G-207-03: High Spatial Resolution and High Sensitivity X-Ray Fluorescence Imaging

    International Nuclear Information System (INIS)

    Xing, L.

    2015-01-01

    Last few years has witnessed the development of novel of X-ray imaging modalities, such as spectral CT, phase contrast CT, and X-ray acoustic/fluorescence/luminescence imaging. This symposium will present the recent advances of these emerging X-ray imaging modalities and update the attendees with knowledge in various related topics, including X-ray photon-counting detectors, X-ray physics underlying the emerging applications beyond the traditional X-ray imaging, image reconstruction for the novel modalities, characterization and evaluation of the systems, and their practical implications. In addition, the concept and practical aspects of X-ray activatable targeted nanoparticles for molecular X-ray imaging will be discussed in the context of X-ray fluorescence and luminescence CT. Learning Objectives: Present background knowledge of various emerging X-ray imaging techniques, such as spectral CT, phase contrast CT and X-ray fluorescence/luminescence CT. Discuss the practical need, technical aspects and current status of the emerging X-ray imaging modalities. Describe utility and future impact of the new generation of X-ray imaging applications

  14. THE BROADBAND XMM-NEWTON AND NuSTAR X-RAY SPECTRA OF TWO ULTRALUMINOUS X-RAY SOURCES IN THE GALAXY IC 342

    Energy Technology Data Exchange (ETDEWEB)

    Rana, Vikram; Harrison, Fiona A.; Walton, Dominic J.; Furst, Felix; Grefenstette, Brian W.; Madsen, Kristin K. [Cahill Center for Astronomy and Astrophysics, California Institute of Technology, Pasadena, CA 91125 (United States); Bachetti, Matteo; Barret, Didier; Webb, Natalie A. [Université de Toulouse, UPS-OMP, IRAP, Toulouse (France); Miller, Jon M. [Department of Astronomy, University of Michigan, 500 Church Street, Ann Arbor, MI 48109-1042 (United States); Fabian, Andrew C. [Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA (United Kingdom); Boggs, Steven E.; Craig, William W. [Space Sciences Laboratory, University of California, Berkeley, CA 94720 (United States); Christensen, Finn C. [DTU Space, National Space Institute, Technical University of Denmark, Elektrovej 327, DK-2800 Lyngby (Denmark); Hailey, Charles J. [Columbia Astrophysics Laboratory, Columbia University, New York, NY 10027 (United States); Ptak, Andrew F.; Zhang, William W. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Stern, Daniel [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States)

    2015-02-01

    We present results for two ultraluminous X-ray sources (ULXs), IC 342 X-1 and IC 342 X-2, using two epochs of XMM-Newton and NuSTAR observations separated by ∼7 days. We observe little spectral or flux variability above 1 keV between epochs, with unabsorbed 0.3-30 keV luminosities being 1.04{sub −0.06}{sup +0.08}×10{sup 40} erg s{sup –1} for IC 342 X-1 and 7.40 ± 0.20 × 10{sup 39} erg s{sup –1} for IC 342 X-2, so that both were observed in a similar, luminous state. Both sources have a high absorbing column in excess of the Galactic value. Neither source has a spectrum consistent with a black hole binary in low/hard state, and both ULXs exhibit strong curvature in their broadband X-ray spectra. This curvature rules out models that invoke a simple reflection-dominated spectrum with a broadened iron line and no cutoff in the illuminating power-law continuum. X-ray spectrum of IC 342 X-1 can be characterized by a soft disk-like blackbody component at low energies and a cool, optically thick Comptonization continuum at high energies, but unique physical interpretation of the spectral components remains challenging. The broadband spectrum of IC 342 X-2 can be fit by either a hot (3.8 keV) accretion disk or a Comptonized continuum with no indication of a seed photon population. Although the seed photon component may be masked by soft excess emission unlikely to be associated with the binary system, combined with the high absorption column, it is more plausible that the broadband X-ray emission arises from a simple thin blackbody disk component. Secure identification of the origin of the spectral components in these sources will likely require broadband spectral variability studies.

  15. High Resolution X-ray Diffraction Dataset for Bacillus licheniformis Gamma Glutamyl Transpeptidase-acivicin complex: SUMO-Tag Renders High Expression and Solubility.

    Science.gov (United States)

    Kumari, Shobha; Pal, Ravi Kant; Gupta, Rani; Goel, Manisha

    2017-02-01

    Gamma glutamyl transpeptidase, (GGT) is a ubiquitous protein which plays a central role in glutathione metabolism and has myriad clinical implications. It has been shown to be a virulence factor for pathogenic bacteria, inhibition of which results in reduced colonization potential. However, existing inhibitors are effective but toxic and therefore search is on for novel inhibitors, which makes it imperative to understand the interactions of various inhibitors with the protein in substantial detail. High resolution structures of protein bound to different inhibitors can serve this purpose. Gamma glutamyl transpeptidase from Bacillus licheniformis is one of the model systems that have been used to understand the structure-function correlation of the protein. The structures of the native protein (PDB code 4OTT), of its complex with glutamate (PDB code 4OTU) and that of its precursor mimic (PDB code 4Y23) are available, although at moderate/low resolution. In the present study, we are reporting the preliminary analysis of, high resolution X-ray diffraction data collected for the co-crystals of B. licheniformis, Gamma glutamyl transpeptidase, with its inhibitor, Acivicin. Crystals belong to the orthorhombic space group P2 1 2 1 2 1 and diffract X-ray to 1.45 Å resolution. This is the highest resolution data reported for all GGT structures available till now. The use of SUMO fused expression system enhanced yield of the target protein in the soluble fraction, facilitating recovery of protein with high purity. The preliminary analysis of this data set shows clear density for the inhibitor, acivicin, in the protein active site.

  16. Quantitative analysis with energy dispersive X-ray fluorescence analyser

    International Nuclear Information System (INIS)

    Kataria, S.K.; Kapoor, S.S.; Lal, M.; Rao, B.V.N.

    1977-01-01

    Quantitative analysis of samples using radioisotope excited energy dispersive x-ray fluorescence system is described. The complete set-up is built around a locally made Si(Li) detector x-ray spectrometer with an energy resolution of 220 eV at 5.94 KeV. The photopeaks observed in the x-ray fluorescence spectra are fitted with a Gaussian function and the intensities of the characteristic x-ray lines are extracted, which in turn are used for calculating the elemental concentrations. The results for a few typical cases are presented. (author)

  17. NEWFIT, a computer program for the analysis of alpha, X-ray and gamma-ray spectra

    International Nuclear Information System (INIS)

    Welch, R.B.; Gyger, F.; Jost, D.T.; Gunten, H.R. von; Kraehenbuehl, U.

    1988-01-01

    The computer program NEWFIT has been developed for analysis of gamma-ray, X-ray and alpha spectra. The general shape used for the analysis of activity peaks is a Gaussian function. An exponential tail can be added for use in alpha spectra analysis. The algorithms to analyze the peak shapes and the program operation are presented. Special features include the ability to create realistic peak shapes based on the systematic deviations of the real peaks from the theoretical Gaussian shape, as well as the option to constrain the calculated areas of peaks from a given emitting nuclide to their relative branching ratios. The program is available from the authors. (orig.)

  18. X-ray emission in heavy-ion collisions. Progress report, April 1, 1979-March 31, 1980

    International Nuclear Information System (INIS)

    Watson, R.L.

    1980-04-01

    Recent research in the cyclotron institute and department of chemistry at Texas A and M University on the x-ray emission in heavy-ion collisions is described. Areas covered include: spectra of Ka x-rays from 64 MeV sulfur ions traveling in solids; foil-excited Ka x-ray transitions in few-electron sulfur ions; high-resolution study of the target thickness dependence of x-ray emission from 65 MeV sulfur ions; dynamic screening of highly stripped sulfur ions in solids; Mg Ka x-ray satellites excited by ion bombardment, multiplet structure and dependence on projectile and chemical environment; angular distributions of beam and target Ka x-rays; chemical effects on K x-ray satellites of fluorine compounds; and a non-linear least-squares peak-fitting program employing Voight functions

  19. Correcting X-ray spectra obtained from the AXAF VETA-I mirror calibration for pileup, continuum, background and deadtime

    Science.gov (United States)

    Chartas, G.; Flanagan, K.; Hughes, J. P.; Kellogg, E. M.; Nguyen, D.; Zombek, M.; Joy, M.; Kolodziejezak, J.

    1993-01-01

    The VETA-I mirror was calibrated with the use of a collimated soft X-ray source produced by electron bombardment of various anode materials. The FWHM, effective area and encircled energy were measured with the use of proportional counters that were scanned with a set of circular apertures. The pulsers from the proportional counters were sent through a multichannel analyzer that produced a pulse height spectrum. In order to characterize the properties of the mirror at different discrete photon energies one desires to extract from the pulse height distribution only those photons that originated from the characteristic line emission of the X-ray target source. We have developed a code that fits a modeled spectrum to the observed X-ray data, extracts the counts that originated from the line emission, and estimates the error in these counts. The function that is fitted to the X-ray spectra includes a Prescott function for the resolution of the detector a second Prescott function for a pileup peak and a X-ray continuum function. The continuum component is determined by calculating the absorption of the target Bremsstrahlung through various filters, correcting for the reflectivity of the mirror and convolving with the detector response.

  20. High intensity line source for x-ray spectrometer calibration

    International Nuclear Information System (INIS)

    Thoe, R.S.

    1986-06-01

    A high intensity electron-impact x-ray source using a one-dimensional Pierce lens has been built for the purpose of calibrating a bent crystal x-ray spectrometer. This source focuses up to 100 mA of 20-keV electrons to a line on a liquid-cooled anode. The line (which can serve as a virtual slit for the spectrometer) measures approximately 800 μ x 2 cm. The source is portable and therefore adaptable to numerous types of spectrometer applications. One particular application, the calibration of a high resolution (r = 10 4 ) time-resolved cyrstal spectrometer, will be discussed in detail

  1. Constellation-X to Generation-X: evolution of large collecting area moderate resolution grazing incidence x-ray telescopes to larger area high-resolution adjustable optics

    Science.gov (United States)

    Reid, Paul B.; Cameron, Robert A.; Cohen, Lester; Elvis, Martin; Gorenstein, Paul; Jerius, Diab; Petre, Robert; Podgorski, William A.; Schwartz, Daniel A.; Zhang, William W.

    2004-10-01

    Large collecting area x-ray telescopes are designed to study the early Universe, trace the evolution of black holes, stars and galaxies, study the chemical evolution of the Universe, and study matter in extreme environments. The Constellation-X mission (Con-X), planned for launch in 2016, will provide ~ 10^4 cm^2 collecting area with 15 arc-sec resolution, with a goal of 5 arc-sec. Future missions require larger collecting area and finer resolution. Generation-X (Gen-X), a NASA Visions Mission, will achieve 100 m^2 effective area at 1 keV and angular resolution of 0.1 arc-sec, half power diameter. We briefly describe the Con-X flowdown of imaging requirements to reflector figure error. To meet requirements beyond Con-X, Gen-X optics will be thinner and more accurately shaped than has ever been accomplished. To meet these challenging goals, we incorporate for the first time active figure control with grazing incidence optics. Piezoelectric material will be deposited in discrete cells directly on the back surface of the optical segments, with the strain directions oriented parallel to the surface. Differential strain between the two layers of the mirror causes localized bending in two directions, enabling local figure control. Adjusting figure on-orbit eases fabrication and metrology. The ability to make changes to mirror figure adds margin by mitigating risk due to launch-induced deformations and/or on-orbit degradation. We flowdown the Gen-X requirements to mirror figure and four telescope designs, and discuss various trades between the designs.

  2. Experimental device for the X-ray energetic distribution measurement in a tokamak plasma

    International Nuclear Information System (INIS)

    Perez-Navarro, A.

    1977-01-01

    An experimental system to measure the X-ray spectrum in a tokamak plasma is described, emphasizing its characteristics: resolution, dead time and the pulse pile-up distortion effects on the X-ray spectra. (author) [es

  3. Effect of Boron Doping on High-Resolution X-Ray Diffraction Metrology

    Science.gov (United States)

    Faheem, M.; Zhang, Y.; Dai, X.

    2018-03-01

    The effect of boron (B) doping on high-resolution X-ray diffraction (HXRD) metrology has been investigated. Twelve samples of Si1-xGex films were epitaxially grown on Si (100) substrates with different thicknesses, germanium (Ge) concentrations and with/without B dopants. Secondary ion mass spectroscopy (SIMS) and HXRD were employed for measurements of B doping, Ge concentration, strain, and thickness of the layers. The SIMS results show the absence of B in two samples while the rest of the samples have B doping in the range of 8.40 × 1018-8.7 × 1020 atoms/cm3 with Ge concentration of 13.3-55.2 at.%. The HXRD measurements indicate the layers thickness of 7.07-108.13 nm along with Ge concentration of 12.82-49.09 at.%. The difference in the Ge concentration measured by SIMS and HXRD was found to deend on B doping. For the undoped samples, the difference is 0.5 at.% and increases with B doping but with no linear proportionality. The difference in the Ge concentration was 7.11 at.% for the highly B-doped (8.7 × 1020 atoms/cm3) sample. The B doping influences the Si1-xGex structure, causing a change in the lattice parameter and producing tensile strains shifting Si1-xGex peaks towards Si (100) substrate peaks in the HXRD diffraction patterns. As a result, Vegard's law is no longer effective and makes a high impact on the HXRD measurement. The comparison between symmetric (004) and asymmetric (+113, +224) reciprocal space mappings (RSM) showed a slight difference in Ge concentration between the undoped and lower B-doped samples. However, there is a change of 0.21 at.% observed for the highly doped Si1-xGex samples. RSM's (+113) demonstrate the small SiGe peak broadening as B doping increases, which indicates a minor crystal distortion.

  4. Direct observation of strain in bulk subgrains and dislocation walls by high angular resolution three-dimensional X-ray diffraction

    DEFF Research Database (Denmark)

    Jakobsen, Bo; Lienert, U.; Almer, J.

    2008-01-01

    The X-ray diffraction (XRD) method "high angular resolution 3DXRD" is briefly introduced, and results are presented for a single bulk grain in a polycrystalline copper sample deformed in tension. It is found that the three-dimensional reciprocal-space intensity distribution of a 400 reflection...

  5. Highly multiplexible thermal kinetic inductance detectors for x-ray imaging spectroscopy

    International Nuclear Information System (INIS)

    Ulbricht, Gerhard; Mazin, Benjamin A.; Szypryt, Paul; Walter, Alex B.; Bockstiegel, Clint; Bumble, Bruce

    2015-01-01

    For X-ray imaging spectroscopy, high spatial resolution over a large field of view is often as important as high energy resolution, but current X-ray detectors do not provide both in the same device. Thermal Kinetic Inductance Detectors (TKIDs) are being developed as they offer a feasible way to combine the energy resolution of transition edge sensors with pixel counts approaching CCDs and thus promise significant improvements for many X-ray spectroscopy applications. TKIDs are a variation of Microwave Kinetic Inductance Detectors (MKIDs) and share their multiplexibility: working MKID arrays with 2024 pixels have recently been demonstrated and much bigger arrays are under development. In this work, we present a TKID prototype, which is able to achieve an energy resolution of 75 eV at 5.9 keV, even though its general design still has to be optimized. We further describe TKID fabrication, characterization, multiplexing, and working principle and demonstrate the necessity of a data fitting algorithm in order to extract photon energies. With further design optimizations, we expect to be able to improve our TKID energy resolution to less than 10 eV at 5.9 keV

  6. Highly multiplexible thermal kinetic inductance detectors for x-ray imaging spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Ulbricht, Gerhard, E-mail: ulbricht@physics.ucsb.edu; Mazin, Benjamin A.; Szypryt, Paul; Walter, Alex B.; Bockstiegel, Clint [Department of Physics, University of California, Santa Barbara, California 93106 (United States); Bumble, Bruce [NASA Jet Propulsion Laboratory, 4800 Oak Grove Drive, Pasadena, California 91125 (United States)

    2015-06-22

    For X-ray imaging spectroscopy, high spatial resolution over a large field of view is often as important as high energy resolution, but current X-ray detectors do not provide both in the same device. Thermal Kinetic Inductance Detectors (TKIDs) are being developed as they offer a feasible way to combine the energy resolution of transition edge sensors with pixel counts approaching CCDs and thus promise significant improvements for many X-ray spectroscopy applications. TKIDs are a variation of Microwave Kinetic Inductance Detectors (MKIDs) and share their multiplexibility: working MKID arrays with 2024 pixels have recently been demonstrated and much bigger arrays are under development. In this work, we present a TKID prototype, which is able to achieve an energy resolution of 75 eV at 5.9 keV, even though its general design still has to be optimized. We further describe TKID fabrication, characterization, multiplexing, and working principle and demonstrate the necessity of a data fitting algorithm in order to extract photon energies. With further design optimizations, we expect to be able to improve our TKID energy resolution to less than 10 eV at 5.9 keV.

  7. Hydrogen atoms in protein structures: high-resolution X-ray diffraction structure of the DFPase

    Science.gov (United States)

    2013-01-01

    Background Hydrogen atoms represent about half of the total number of atoms in proteins and are often involved in substrate recognition and catalysis. Unfortunately, X-ray protein crystallography at usual resolution fails to access directly their positioning, mainly because light atoms display weak contributions to diffraction. However, sub-Ångstrom diffraction data, careful modeling and a proper refinement strategy can allow the positioning of a significant part of hydrogen atoms. Results A comprehensive study on the X-ray structure of the diisopropyl-fluorophosphatase (DFPase) was performed, and the hydrogen atoms were modeled, including those of solvent molecules. This model was compared to the available neutron structure of DFPase, and differences in the protein and the active site solvation were noticed. Conclusions A further examination of the DFPase X-ray structure provides substantial evidence about the presence of an activated water molecule that may constitute an interesting piece of information as regard to the enzymatic hydrolysis mechanism. PMID:23915572

  8. 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

  9. 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

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

    International Nuclear Information System (INIS)

    Thorn, D. B.

    2008-01-01

    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 the effect of the

  11. Determination of x-ray spectra incident on and transmitted through whole excised breast for improved mammographic exposing technique

    International Nuclear Information System (INIS)

    Haus, A.G.; Metz, C.E.; Doi, K.; Bernstein, J.

    1976-01-01

    Measurements were made of x-ray spectra incident on and transmitted through whole excised fresh breast tissue. The spectra and corresponding radiographs show that hardening of the x-ray beam from a molybdenum anode x-ray tube by a 0.5 mm Al filter instead of the conventional 0.03 mm Mo filter allows shorter exposure times and reduces patient radiation exposure. With the Al filter, acceptable image contrast is preserved in mammography of thick or dense breasts

  12. Influence of smoothing of X-ray spectra on parameters of calibration model

    International Nuclear Information System (INIS)

    Antoniak, W.; Urbanski, P.; Kowalska, E.

    1998-01-01

    Parameters of the calibration model before and after smoothing of X-ray spectra have been investigated. The calibration model was calculated using multivariate procedure - namely the partial least square regression (PLS). Investigations have been performed on an example of six sets of various standards used for calibration of some instruments based on X-ray fluorescence principle. The smoothing methods were compared: regression splines, Savitzky-Golay and Discrete Fourier Transform. The calculations were performed using a software package MATLAB and some home-made programs. (author)

  13. The influence of magnetic field geometry on magnetars X-ray spectra

    International Nuclear Information System (INIS)

    Viganò, D; Pons, J A; Miralles, J A; Parkins, N; Zane, S; Turolla, R

    2012-01-01

    Nowadays, the analysis of the X-ray spectra of magnetically powered neutron stars or magnetars is one of the most valuable tools to gain insight into the physical processes occurring in their interiors and magnetospheres. In particular, the magnetospheric plasma leaves a strong imprint on the observed X-ray spectrum by means of Compton up-scattering of the thermal radiation coming from the star surface. Motivated by the increased quality of the observational data, much theoretical work has been devoted to develop Monte Carlo (MC) codes that incorporate the effects of resonant Compton scattering (RCS) in the modeling of radiative transfer of photons through the magnetosphere. The two key ingredients in this simulations are the kinetic plasma properties and the magnetic field (MF) configuration. The MF geometry is expected to be complex, but up to now only mathematically simple solutions (self-similar solutions) have been employed. In this work, we discuss the effects of new, more realistic, MF geometries on synthetic spectra. We use new force-free solutions [14] in a previously developed MC code [9] to assess the influence of MF geometry on the emerging spectra. Our main result is that the shape of the final spectrum is mostly sensitive to uncertain parameters of the magnetospheric plasma, but the MF geometry plays an important role on the angle-dependence of the spectra.

  14. 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....... In contrast to the deformation stages, during each stress relaxation stage, number, size and orientation of subgrains are found to be constant, while a minor amount of clean-up of the microstructure is observed as narrowing of the radial X-ray diffraction line profile. The associated decrease in the width...

  15. High-resolution non-invasive 3D imaging of paint microstructure by synchrotron-based X-ray laminography

    International Nuclear Information System (INIS)

    Reischig, Peter; Helfen, Lukas; Wallert, Arie; Baumbach, Tilo; Dik, Joris

    2013-01-01

    The characterisation of the microstructure and micromechanical behaviour of paint is key to a range of problems related to the conservation or technical art history of paintings. Synchrotron-based X-ray laminography is demonstrated in this paper to image the local sub-surface microstructure in paintings in a non-invasive and non-destructive way. Based on absorption and phase contrast, the method can provide high-resolution 3D maps of the paint stratigraphy, including the substrate, and visualise small features, such as pigment particles, voids, cracks, wood cells, canvas fibres etc. Reconstructions may be indicative of local density or chemical composition due to increased attenuation of X-rays by elements of higher atomic number. The paint layers and their interfaces can be distinguished via variations in morphology or composition. Results of feasibility tests on a painting mockup (oak panel, chalk ground, vermilion and lead white paint) are shown, where lateral and depth resolution of up to a few micrometres is demonstrated. The method is well adapted to study the temporal evolution of the stratigraphy in test specimens and offers an alternative to destructive sampling of original works of art. (orig.)

  16. High-speed X-ray phase tomography with Talbot interferometer and fringe scanning method

    International Nuclear Information System (INIS)

    Kibayashi, Shunsuke; Harasse, Sébastien; Yashiro, Wataru; Momose, Atsushi

    2012-01-01

    High-speed X-ray phase tomography based on the Fourier-transform method has been demonstrated with an X-ray Talbot interferometer using white synchrotron radiation. We report the experimental results of high-speed X-ray phase tomography with fringe-scanning method instead of Fourier-transform method to improve spatial resolution without a considerable increase of scan time. To apply fringe-scanning method to high speed tomography, we tested a scan that is a synchronous combination of one-way continuous movements of the sample rotation and the grating displacement. When this scanning method was combined with X-ray phase tomography, we were able to obtain a scan time of 5 s. A comparison of the image quality derived with the conventional approach and with the proposed approach using the fringe-scanning method showed that the latter had better spatial resolution.

  17. Restricted active space calculations of L-edge X-ray absorption spectra: from molecular orbitals to multiplet states.

    Science.gov (United States)

    Pinjari, Rahul V; Delcey, Mickaël G; Guo, Meiyuan; Odelius, Michael; Lundberg, Marcus

    2014-09-28

    The metal L-edge (2p → 3d) X-ray absorption spectra are affected by a number of different interactions: electron-electron repulsion, spin-orbit coupling, and charge transfer between metal and ligands, which makes the simulation of spectra challenging. The core restricted active space (RAS) method is an accurate and flexible approach that can be used to calculate X-ray spectra of a wide range of medium-sized systems without any symmetry constraints. Here, the applicability of the method is tested in detail by simulating three ferric (3d(5)) model systems with well-known electronic structure, viz., atomic Fe(3+), high-spin [FeCl6](3-) with ligand donor bonding, and low-spin [Fe(CN)6](3-) that also has metal backbonding. For these systems, the performance of the core RAS method, which does not require any system-dependent parameters, is comparable to that of the commonly used semi-empirical charge-transfer multiplet model. It handles orbitally degenerate ground states, accurately describes metal-ligand interactions, and includes both single and multiple excitations. The results are sensitive to the choice of orbitals in the active space and this sensitivity can be used to assign spectral features. A method has also been developed to analyze the calculated X-ray spectra using a chemically intuitive molecular orbital picture.

  18. Radio and X-ray observations of a multiple impulsive solar burst with high time resolution

    International Nuclear Information System (INIS)

    Kosugi, T.

    1981-01-01

    A well-developed multiple impulsive microwave burst occurred on February 17, 1979 simultaneously with a hard X-ray burst and a large group of type III bursts at metric wavelengths. The whole event is composed of serveral subgroups of elementary spike bursts. Detailed comparisons between these three classes of emissions with high time resolution of approx. equal to0.5 s reveal that individual type III bursts coincide in time with corresponding elementary X-ray and microwave spike bursts. It suggests that a non-thermal electron pulse generating a type III spike burst is produced simultaneously with those responsible for the corresponding hard X-ray and microwave spike bursts. The rise and decay characteristic time scales of the elementary spike burst are << 1 s, and approx. equal to1 s and approx. equal to3 s for type III, hard X-ray and microwave emissions respectively. Radio interferometric observations made at 17 GHz reveal that the spatial structure varies from one subgroup to others while it remains unchanged in a subgroup. Spectral evolution of the microwave burst seems to be closely related to the spatial evolution. The spatial evolution together with the spectral evolution suggests that the electron-accelerating region shifts to a different location after it stays at one location for several tens of seconds, duration of a subgroup of elementary spike bursts. We discuss several requirements for a model of the impulsive burst which come out from these observational results, and propose a migrating double-source model. (orig.)

  19. Fluorescence-type Monochromatic X-ray Beam-position Monitor with High-spatial Resolution for the NSLS-II Beamlines

    International Nuclear Information System (INIS)

    Yoon, Phil S.; Siddons, D. Peter

    2010-01-01

    We developed a fluorescence-type monochromatic X-ray beam-position monitor (X-BPM) with high-spatial resolution for end-station experiments at the initial project beamlines of the NSLS-II. We designed a ring array of multi-segmented Si PIN-junction photodiodes to use as a position sensor. Further, we integrated a low-noise charge-preamplification HERMES4 ASIC chip into an electronic readout system for photon-counting application. A series of precision measurements to characterize electronically the Si-photodiode sensor and the ASIC chip demonstrated that the inherent noise from the detector system is sufficiently low to meet our stringent requirements. Using a Gaussian beam, we parametrically modeled the optimum working distance to ensure the detector's best performance. Based upon the results from the parametric modeling, prototypes of the next versions of the X-BPM are being developed. In this paper, we describe the methodology for developing the new compact monochromatic X-ray BPM, including its instrumentation, detector modeling, and future plan.

  20. 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

  1. Modeling of X-ray images and energy spectra produced by stepping lightning leaders

    OpenAIRE

    Xu , Wei; Marshall , Robert A.; Celestin , Sébastien; Pasko , Victor P.

    2017-01-01

    International audience; Recent ground-based measurements at the International Center for Lightning Research and Testing (ICLRT) have greatly improved our knowledge of the energetics, fluence, and evolution of X-ray emissions during natural cloud-to-ground (CG) and rocket-triggered lightning flashes. In this paper, using Monte Carlo simulations and the response matrix of unshielded detectors in the Thunderstorm Energetic Radiation Array (TERA), we calculate the energy spectra of X-rays as woul...

  2. A method to unfold the efficiency of gaseous detectors exposed to broad X-ray spectra

    International Nuclear Information System (INIS)

    Almeida, Gevaldo L. de; Souza, Maria Ines S. de; Lopes, Ricardo T.

    2000-01-01

    A method to obtain the efficiency of a gaseous detector exposed to broad energy X-ray spectra was developed. It consists in the de-convolution of the integrated detector response using the shapes of those spectra as a tool to unfold the aimed detector efficiency curve. For this purpose, the spectra emitted by a X-ray tube under several anode voltages, were properly characterized through measurements with a NaI(Tl) spectrometer. A Lorentz function was then fitted to each of the spectra, and their parameters expressed as a function of the anode voltage, by using polynomial and gaussian fittings. The integral of the product of each Lorentz function, by another unknown Lorentz function, expressing the detector efficiency curve, represents the response of the detector for each anode tension, e.g., each X-ray spectrum. The symbolical integration of that product, produces a general function containing the unknown parameters of the unknown efficiency curve. A non-linear fitting of this general function, to the detector response points, as experimentally obtained, generates the aimed parameters for the efficiency curve. The final detector efficiency curve is obtained after normalization procedures. (author)

  3. Pulsator-like Spectra from Ultraluminous X-Ray Sources and the Search for More Ultraluminous Pulsars

    International Nuclear Information System (INIS)

    Pintore, F.; Mereghetti, S.; Zampieri, L.; Stella, L.; Israel, G. L.; Wolter, A.

    2017-01-01

    Ultraluminous X-ray sources (ULXs) are a population of extragalactic objects whose luminosity exceeds the Eddington limit for a 10 M ⊙ black hole (BH). Their properties have been widely interpreted in terms of accreting stellar-mass or intermediate-mass BHs. However at least three neutron stars (NSs) have been recently identified in ULXs through the discovery of periodic pulsations. Motivated by these findings we studied the spectral properties of a sample of bright ULXs using a simple continuum model which was extensively used to fit the X-ray spectra of accreting magnetic NSs in the Galaxy. We found that such a model, consisting of a power-law with a high-energy exponential cut-off, fits most of the ULX spectra analyzed here very well, at a level comparable to that of models involving an accreting BH. On these grounds alone we suggest that other non-pulsating ULXs may host NSs. We also found that above 2 keV the spectrum of known pulsating ULXs is harder than that of the majority of the other ULXs of the sample, with only IC 342 X-1 and Ho IX X-1 displaying spectra of comparable hardness. We thus suggest that these two ULXs may host an accreting NS and encourage searches for periodic pulsations in the flux.

  4. Pulsator-like Spectra from Ultraluminous X-Ray Sources and the Search for More Ultraluminous Pulsars

    Energy Technology Data Exchange (ETDEWEB)

    Pintore, F.; Mereghetti, S. [INAF-IASF Milano, via E. Bassini 15, I-20133 Milano (Italy); Zampieri, L. [INAF-Osservatorio Astronomico di Padova, Vicolo dell’Osservatorio 5, I-35122 Padova (Italy); Stella, L.; Israel, G. L. [INAF—Osservatorio astronomico di Roma, Via Frascati 44, I-00078, Monteporzio Catone (Italy); Wolter, A. [INAF, Osservatorio Astronomico di Brera, via Brera 28, I-20121 Milano (Italy)

    2017-02-10

    Ultraluminous X-ray sources (ULXs) are a population of extragalactic objects whose luminosity exceeds the Eddington limit for a 10 M {sub ⊙} black hole (BH). Their properties have been widely interpreted in terms of accreting stellar-mass or intermediate-mass BHs. However at least three neutron stars (NSs) have been recently identified in ULXs through the discovery of periodic pulsations. Motivated by these findings we studied the spectral properties of a sample of bright ULXs using a simple continuum model which was extensively used to fit the X-ray spectra of accreting magnetic NSs in the Galaxy. We found that such a model, consisting of a power-law with a high-energy exponential cut-off, fits most of the ULX spectra analyzed here very well, at a level comparable to that of models involving an accreting BH. On these grounds alone we suggest that other non-pulsating ULXs may host NSs. We also found that above 2 keV the spectrum of known pulsating ULXs is harder than that of the majority of the other ULXs of the sample, with only IC 342 X-1 and Ho IX X-1 displaying spectra of comparable hardness. We thus suggest that these two ULXs may host an accreting NS and encourage searches for periodic pulsations in the flux.

  5. Vibrational spectra, powder X-ray diffractions and physical properties of cyanide complexes with 1-ethylimidazole

    Science.gov (United States)

    Kürkçüoğlu, Güneş Süheyla; Kiraz, Fulya Çetinkaya; Sayın, Elvan

    2015-10-01

    The heteronuclear tetracyanonickelate(II) complexes of the type [M(etim)Ni(CN)4]n (hereafter, abbreviated as M-Ni-etim, M = Mn(II), Fe(II) or Co(II); etim = 1-ethylimidazole, C5H8N2) were prepared in powder form and characterized by FT-IR and Raman spectroscopy, powder X-ray diffraction (PXRD), thermal (TG; DTG and DTA), and elemental analysis techniques. The structures of these complexes were elucidated using vibrational spectra and powder X-ray diffraction patterns with the peak assignment to provide a better understanding of the structures. It is shown that the spectra are consistent with a proposed crystal structure for these compounds derived from powder X-ray diffraction measurements. Vibrational spectra of the complexes were presented and discussed with respect to the internal modes of both the etim and the cyanide ligands. The C, H and N analyses were carried out for all the complexes. Thermal behaviors of these complexes were followed using TG, DTG and DTA curves in the temperature range 30-700 °C in the static air atmosphere. The FT-IR, Raman spectra, thermal and powder X-ray analyses revealed no significant differences between the single crystal and powder forms. Additionally, electrical and magnetic properties of the complexes were investigated. The FT-IR and Raman spectroscopy, PXRD, thermal and elemental analyses results propose that these complexes are similar in structure to the Hofmann-type complexes.

  6. X-ray spectra and time variability of active galactic nuclei

    International Nuclear Information System (INIS)

    Mushotzky, R.F.

    1984-02-01

    The X-ray spectra of broad line active galactic nuclei (AGN) of all types (Seyfert I's, NELG's, broadline radio galaxies) are well fit by a power law in the .5 to 100 keV band of man energy slope alpha .68 + or - .15. There is, as yet, no strong evidence for time variability of this slope in a given object. The constraints that this places on simple models of the central energy source are discussed. BL Lac objects have quite different X-ray spectral properties and show pronounced X-ray spectral variability. On time scales longer than 12 hours most radio quiet AGN do not show strong, delta I/I .5, variability. The probability of variability of these AGN seems to be inversely related to their luminosity. However characteristics timescales for variability have not been measured for many objects. This general lack of variability may imply that most AGN are well below the Eddington limit. Radio bright AGN tend to be more variable than radio quiet AGN on long, tau approx 6 month, timescales

  7. X-Ray Absorption Spectra of Amorphous Ices from GW Quasiparticle Calculation

    Science.gov (United States)

    Kong, Lingzhu; Car, Roberto

    2013-03-01

    We use a GW approach[2] to compute the x-ray absorption spectra of model low- and high-density amorphous ice structures(LDA and HDA)[3]. We include the structural effects of quantum zero point motion using colored-noise Langevin molecular dynamics[4]. The calculated spectra differences in the main and post edge region between LDA and HDA agree well with experimental observations. We attribute these differences to the presence of interstitial molecules within the first coordination shell range in HDA. This assignment is further supported by a calculation of the spectrum of ice VIII, a high-pressure structure that maximizes the number of interstitial molecules and, accordingly, shows a much weaker post-edge feature. We further rationalize the spectral similarity between HDA and liquid water, and between LDA and ice Ih in terms of the respective similarities in the H-bond network topology and bond angle distributions. Supported by grants DOE-DE-SC0005180, DOE DE-SC0008626 and NSF-CHE-0956500.

  8. Internal structure of InP/ZnS nanocrystals unraveled by high-resolution soft X-ray photoelectron spectroscopy.

    Science.gov (United States)

    Huang, Kai; Demadrille, Renaud; Silly, Mathieu G; Sirotti, Fausto; Reiss, Peter; Renault, Olivier

    2010-08-24

    High-energy resolution photoelectron spectroscopy (DeltaE InP/ZnS core/shell nanocrystals synthesized using a single-step procedure (core and shell precursors added at the same time), a homogeneously alloyed InPZnS core structure is evidenced by quantitative analysis of their In3d(5/2) spectra recorded at variable excitation energy. When using a two-step method (core InP nanocrystal synthesis followed by subsequent ZnS shell growth), XPS analysis reveals a graded core/shell interface. We demonstrate the existence of In-S and S(x)-In-P(1-x) bonding states in both types of InP/ZnS nanocrystals, which allows a refined view on the underlying reaction mechanisms.

  9. A low power x-ray tube for use in energy dispersive x-ray fluorescence analysis

    International Nuclear Information System (INIS)

    Kataria, S.K.; Govil, Rekha; Lal, M.

    1980-01-01

    A low power X-ray tube with thin molybdenum transmission target for use in energy dispersive X-ray fluorescence (ENDXRF) element analysis has been indigenously built, along with its power supply. The X-ray tube has been in operation since August 1979, and it has been operated upto maximum target voltage of 35 KV and tube current upto 200 μA which is more than sufficient for trace element analysis. This X-ray tube has been used alongwith the indigenously built Si(Li) detector X-ray spectrometer with an energy resolution of 200 eV at 5.9 Kev MnKsub(α) X-ray peak for ENDXRF analysis. A simple procedure of calibration has been developed for thin samples based on the cellulose diluted, thin multielement standard pellets. Analytical sensitivities of the order of a few p.p.m. have been obtained with the experimental setup for elements with 20 < = Z < = 38 and 60 < = Z < = 90. A number of X-ray spectra for samples of environmental, biological, agricultural, industrial and metallurgical interest are presented to demonstrate the salient features of the experimental sep up. (auth.)

  10. Quantifying the effect of anode surface roughness on diagnostic x-ray spectra using Monte Carlo simulation

    Energy Technology Data Exchange (ETDEWEB)

    Mehranian, A.; Ay, M. R.; Alam, N. Riyahi; Zaidi, H. [Department of Medical Physics and Biomedical Engineering, Tehran University of Medical Sciences, P.O. Box 14155-6447, Tehran (Iran, Islamic Republic of) and Research Center for Science and Technology in Medicine, Tehran University of Medical Sciences, P.O. Box 14185-615, Tehran (Iran, Islamic Republic of); Department of Medical Physics and Biomedical Engineering, Tehran University of Medical Sciences, P.O. Box 14155-6447, Tehran (Iran, Islamic Republic of); Research Center for Science and Technology in Medicine, Tehran University of Medical Sciences, P.O. Box 14185-615, Tehran (Iran, Islamic Republic of) and Research Institute for Nuclear Medicine, Tehran University of Medical Sciences, P.O. Box 14155-6447, Tehran (Iran, Islamic Republic of); Department of Medical Physics and Biomedical Engineering, Tehran University of Medical Sciences, P.O. Box 14155-6447, Tehran (Iran, Islamic Republic of); Division of Nuclear Medicine, Geneva University Hospital, CH-1211 Geneva (Switzerland) and Geneva Neuroscience Center, Geneva University, CH-1205 Geneva (Switzerland)

    2010-02-15

    Purpose: The accurate prediction of x-ray spectra under typical conditions encountered in clinical x-ray examination procedures and the assessment of factors influencing them has been a long-standing goal of the diagnostic radiology and medical physics communities. In this work, the influence of anode surface roughness on diagnostic x-ray spectra is evaluated using MCNP4C-based Monte Carlo simulations. Methods: An image-based modeling method was used to create realistic models from surface-cracked anodes. An in-house computer program was written to model the geometric pattern of cracks and irregularities from digital images of focal track surface in order to define the modeled anodes into MCNP input file. To consider average roughness and mean crack depth into the models, the surface of anodes was characterized by scanning electron microscopy and surface profilometry. It was found that the average roughness (R{sub a}) in the most aged tube studied is about 50 {mu}m. The correctness of MCNP4C in simulating diagnostic x-ray spectra was thoroughly verified by calling its Gaussian energy broadening card and comparing the simulated spectra with experimentally measured ones. The assessment of anode roughness involved the comparison of simulated spectra in deteriorated anodes with those simulated in perfectly plain anodes considered as reference. From these comparisons, the variations in output intensity, half value layer (HVL), heel effect, and patient dose were studied. Results: An intensity loss of 4.5% and 16.8% was predicted for anodes aged by 5 and 50 {mu}m deep cracks (50 kVp, 6 deg. target angle, and 2.5 mm Al total filtration). The variations in HVL were not significant as the spectra were not hardened by more than 2.5%; however, the trend for this variation was to increase with roughness. By deploying several point detector tallies along the anode-cathode direction and averaging exposure over them, it was found that for a 6 deg. anode, roughened by 50 {mu}m deep

  11. Theory and optical design of x-ray echo spectrometers

    Science.gov (United States)

    Shvyd'ko, Yuri

    2017-08-01

    X-ray echo spectroscopy, a space-domain counterpart of neutron spin echo, is a recently proposed inelastic x-ray scattering (IXS) technique. X-ray echo spectroscopy relies on imaging IXS spectra and does not require x-ray monochromatization. Due to this, the echo-type IXS spectrometers are broadband, and thus have a potential to simultaneously provide dramatically increased signal strength, reduced measurement times, and higher resolution compared to the traditional narrow-band scanning-type IXS spectrometers. The theory of x-ray echo spectrometers presented earlier [Yu. Shvyd'ko, Phys. Rev. Lett. 116, 080801 (2016), 10.1103/PhysRevLett.116.080801] is developed here further with a focus on questions of practical importance, which could facilitate optical design and assessment of the feasibility and performance of the echo spectrometers. Among others, the following questions are addressed: spectral resolution, refocusing condition, echo spectrometer tolerances, refocusing condition adjustment, effective beam size on the sample, spectral window of imaging and scanning range, impact of the secondary source size on the spectral resolution, angular dispersive optics, focusing and collimating optics, and detector's spatial resolution. Examples of optical designs and characteristics of echo spectrometers with 1-meV and 0.1-meV resolutions are presented.

  12. OSO 8 X-ray spectra of clusters of galaxies. I - Observations of twenty clusters: Physical correlations

    Science.gov (United States)

    Mushotzky, R. F.; Serlemitsos, P. J.; Boldt, E. A.; Holt, S. S.; Smith, B. W.

    1978-01-01

    OSO 8 X-ray spectra from 2 to 20 keV have been analyzed for 26 clusters of galaxies. For 20 clusters temperatures, emission integrals, iron abundances, and low-energy absorption measurements are presented. The data give, in general, better fits to thermal bremsstrahlung than to power-law models. Eight clusters have positive iron emission-line detections at the 90% confidence level, and all 20 cluster spectra are consistent with Fe/H = 0.000014 by number with the possible exception of Virgo. Thus it is confirmed that X-ray emission in this energy band is predominantly thermal radiation from hot intracluster gas rather than inverse Compton radiation. Physical correlations between X-ray spectral parameters and other cluster properties are examined. It is found that (1) the X-ray temperature is approximately proportional to the square of the velocity dispersion of the galaxies; (2) the emission integral is a strong function of the X-ray temperature; (3) the X-ray temperature and emission integral are better correlated with cluster central-galaxy density than with richness; and (4) the fraction of galaxies which are spirals is correlated with the observed ram pressure in the cluster core.

  13. High resolution x-ray diffraction analysis of annealed low-temperature gallium arsenide

    Science.gov (United States)

    Matyi, R. J.; Melloch, M. R.; Woodall, J. M.

    1992-05-01

    High resolution x-ray diffraction methods have been used to characterize GaAs grown at low substrate temperatures by molecular beam epitaxy and to examine the effects of post-growth annealing on the structure of the layers. Double crystal rocking curves from the as-deposited epitaxial layer show well-defined interference fringes, indicating a high level of structural perfection despite the presence of excess arsenic. Annealing at temperatures from 700 to 900 °C resulted in a decrease in the perpendicular lattice mismatch between the GaAs grown at low temperature and the substrate from 0.133% to 0.016% and a decrease (but not total elimination) of the visibility of the interference fringes. Triple-crystal diffraction scans around the 004 point in reciprocal space exhibited an increase in the apparent mosaic spread of the epitaxial layer with increasing anneal temperature. The observations are explained in terms of the growth of arsenic precipitates in the epitaxial layer.

  14. Using x-ray computed tomography in hydrology: Systems, resolutions, and limitations

    DEFF Research Database (Denmark)

    Wildenschild, Dorthe; Hopmans, J.W.; Vaz, C.M.P.

    2002-01-01

    media, obtained with different scanning systems and sample sizes, to illustrate advantages and limitations of these various systems, including topics of spatial resolution and contrast. In addition, we present examples of our most recent three-dimensional high-resolution images, for which......A combination of advances in experimental techniques and mathematical analysis has made it possible to characterize phase distribution and pore geometry in porous media using non-destructive X-ray computed tomography (CT). We present qualitative and quantitative CT results for partially saturated...

  15. Crossover and valence band Kβ X-rays of chromium oxides

    International Nuclear Information System (INIS)

    Fazinic, Stjepko; Mandic, Luka; Kavcic, Matjaz; Bozicevic, Iva

    2011-01-01

    X-ray spectra of chromium metal and selected chromium oxides were measured twice using medium resolution flat crystal spectrometer and high resolution spectrometer employing Johansson geometry after excitation with 2 MeV proton beams. The positions and intensities of crossover (Kβ'') and valence (Kβ 2,5 ) band X-rays relative to the primary Kβ X-ray components were extracted in a consistent way. The results were compared with the existing data obtained by proton and photon induced ionization mechanisms and theoretical predictions. The obtained results in peak relative positions and intensities were analyzed in order to study dependence on the chromium oxidation states and chromium-oxygen bond lengths in selected chromium oxides. Our results obtained by both spectrometers confirm that the linear trend observed for the valence peak relative energy shift as a function of chromium oxidation number does not depend on the experimental resolution. Experimental results for normalized intensities (i.e. relative intensities divided with the number of chromium-oxygen pairs) of crossover and valence band X-rays obtained by both spectrometers are in very good agreement, and follow exponential relationship with the average Cr-O bond lengths in corresponding chromium oxides. The observed trends in crossover and valence X-rays normalized intensities could be used to measure the average chromium-oxygen bond length in various chromium oxides, with the sum of both crossover and valence X-ray normalized intensities being the most sensitive measure.

  16. Equally sloped X-ray microtomography of living insects with low radiation dose and improved resolution capability

    International Nuclear Information System (INIS)

    Yao, Shengkun; Fan, Jiadong; Zong, Yunbing; Sun, Zhibin; Zhang, Jianhua; Jiang, Huaidong; He, You; Zhou, Guangzhao; Xiao, Tiqiao; Huang, Qingjie

    2016-01-01

    Three-dimensional X-ray imaging of living specimens is challenging due to the limited resolution of conventional absorption contrast X-ray imaging and potential irradiation damage of biological specimens. In this letter, we present microtomography of a living specimen combining phase-contrast imaging and a Fourier-based iterative algorithm termed equally sloped tomography. Non-destructive 3D imaging of an anesthetized living yellow mealworm Tenebrio molitor was demonstrated with a relatively low dose using synchrotron generated X-rays. Based on the high-quality 3D images, branching tracheoles and different tissues of the insect in a natural state were identified and analyzed, demonstrating a significant advantage of the technique over conventional X-ray radiography or histotomy. Additionally, the insect survived without problem after a 1.92-s X-ray exposure and subsequent absorbed radiation dose of ∼1.2 Gy. No notable physiological effects were observed after reviving the insect from anesthesia. The improved static tomographic method demonstrated in this letter shows advantage in the non-destructive structural investigation of living insects in three dimensions due to the low radiation dose and high resolution capability, and offers many potential applications in biological science.

  17. Equally sloped X-ray microtomography of living insects with low radiation dose and improved resolution capability

    Science.gov (United States)

    Yao, Shengkun; Fan, Jiadong; Zong, Yunbing; He, You; Zhou, Guangzhao; Sun, Zhibin; Zhang, Jianhua; Huang, Qingjie; Xiao, Tiqiao; Jiang, Huaidong

    2016-03-01

    Three-dimensional X-ray imaging of living specimens is challenging due to the limited resolution of conventional absorption contrast X-ray imaging and potential irradiation damage of biological specimens. In this letter, we present microtomography of a living specimen combining phase-contrast imaging and a Fourier-based iterative algorithm termed equally sloped tomography. Non-destructive 3D imaging of an anesthetized living yellow mealworm Tenebrio molitor was demonstrated with a relatively low dose using synchrotron generated X-rays. Based on the high-quality 3D images, branching tracheoles and different tissues of the insect in a natural state were identified and analyzed, demonstrating a significant advantage of the technique over conventional X-ray radiography or histotomy. Additionally, the insect survived without problem after a 1.92-s X-ray exposure and subsequent absorbed radiation dose of ˜1.2 Gy. No notable physiological effects were observed after reviving the insect from anesthesia. The improved static tomographic method demonstrated in this letter shows advantage in the non-destructive structural investigation of living insects in three dimensions due to the low radiation dose and high resolution capability, and offers many potential applications in biological science.

  18. Equally sloped X-ray microtomography of living insects with low radiation dose and improved resolution capability

    Energy Technology Data Exchange (ETDEWEB)

    Yao, Shengkun; Fan, Jiadong; Zong, Yunbing; Sun, Zhibin; Zhang, Jianhua; Jiang, Huaidong, E-mail: hdjiang@sdu.edu.cn [State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100 (China); He, You; Zhou, Guangzhao; Xiao, Tiqiao [Shanghai Synchrotron Radiation Facility, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800 (China); Huang, Qingjie [School of Information Science and Engineering, Shandong University, Jinan 250100 (China)

    2016-03-21

    Three-dimensional X-ray imaging of living specimens is challenging due to the limited resolution of conventional absorption contrast X-ray imaging and potential irradiation damage of biological specimens. In this letter, we present microtomography of a living specimen combining phase-contrast imaging and a Fourier-based iterative algorithm termed equally sloped tomography. Non-destructive 3D imaging of an anesthetized living yellow mealworm Tenebrio molitor was demonstrated with a relatively low dose using synchrotron generated X-rays. Based on the high-quality 3D images, branching tracheoles and different tissues of the insect in a natural state were identified and analyzed, demonstrating a significant advantage of the technique over conventional X-ray radiography or histotomy. Additionally, the insect survived without problem after a 1.92-s X-ray exposure and subsequent absorbed radiation dose of ∼1.2 Gy. No notable physiological effects were observed after reviving the insect from anesthesia. The improved static tomographic method demonstrated in this letter shows advantage in the non-destructive structural investigation of living insects in three dimensions due to the low radiation dose and high resolution capability, and offers many potential applications in biological science.

  19. Towards 10 meV resolution: The design of an ultrahigh resolution soft X-ray RIXS spectrometer.

    Science.gov (United States)

    Dvorak, Joseph; Jarrige, Ignace; Bisogni, Valentina; Coburn, Scott; Leonhardt, William

    2016-11-01

    We present the optical design of the Centurion soft X-ray resonant inelastic X-ray scattering (RIXS) spectrometer to be located on the SIX beamline at NSLS-II. The spectrometer is designed to reach a resolving power of 100 000 at 1000 eV at its best resolution. It is also designed to have continuously variable 2θ motion over a range of 112° using a custom triple rotating flange. We have analyzed several possible spectrometer designs capable of reaching the target resolution. After careful analysis, we have adopted a Hettrick-Underwood spectrometer design, with an additional plane mirror to maintain a fixed direction for the outgoing beam. The spectrometer can cancel defocus and coma aberrations at all energies, has an erect focal plane, and minimizes mechanical motions of the detector. When the beamline resolution is accounted for, the net spectral resolution will be 14 meV at 1000 eV. This will open up many low energy excitations to study and will expand greatly the power of soft X-ray RIXS.

  20. Towards 10 meV resolution: The design of an ultrahigh resolution soft X-ray RIXS spectrometer

    Science.gov (United States)

    Dvorak, Joseph; Jarrige, Ignace; Bisogni, Valentina; Coburn, Scott; Leonhardt, William

    2016-11-01

    We present the optical design of the Centurion soft X-ray resonant inelastic X-ray scattering (RIXS) spectrometer to be located on the SIX beamline at NSLS-II. The spectrometer is designed to reach a resolving power of 100 000 at 1000 eV at its best resolution. It is also designed to have continuously variable 2θ motion over a range of 112° using a custom triple rotating flange. We have analyzed several possible spectrometer designs capable of reaching the target resolution. After careful analysis, we have adopted a Hettrick-Underwood spectrometer design, with an additional plane mirror to maintain a fixed direction for the outgoing beam. The spectrometer can cancel defocus and coma aberrations at all energies, has an erect focal plane, and minimizes mechanical motions of the detector. When the beamline resolution is accounted for, the net spectral resolution will be 14 meV at 1000 eV. This will open up many low energy excitations to study and will expand greatly the power of soft X-ray RIXS.

  1. An iterative method for unfolding time-resolved soft x-ray spectra of laser plasmas

    International Nuclear Information System (INIS)

    Tang Yongjian; Shen Kexi; Xu Hepin

    1991-01-01

    Dante-recorded temporal waveforms have been unfolded by using Fast Fourier transformation (FFT) and the inverted convolution theorem of Fourier analysis. The conversion of the signals to time-dependent soft x-ray spectra is accomplished on the IBM-PC/XT-286 microcomputer system with the code DTSP including SAND II reported by W.N.Mcelory et al.. An amplitude-limited iterative and periodic smoothing technique has been developed in the code DTSP. Time-resolved soft x-ray spectra with sixteen time-cell, and time-dependent radiation, [T R (t)], have been obtained for hohlraum targets irradiated with laser beams (λ = 1.06 μm) on LF-12 in 1989

  2. Simulation of pulse height analysis soft X-ray spectra expected from W7-X

    Science.gov (United States)

    Jabłoński, S.; Czarnecka, A.; Kubkowska, M.; Ryć, L.; Weller, A.; Biedermann, C.; König, R.; W7-X Team

    2015-10-01

    A computer code named RayX has been developed for checking the performance of a spectroscopy system and optimizing individual parts, like detectors and filters for the pulse height analysis (PHA) diagnostic system designed for the stellarator W7-X. Using the code, the intensity and shape of the X-ray spectra are simulated for different plasma scenarios characterized by varying the temperature and density profiles as well as the electron cyclotron resonance heating (ECRH) power over a wide range. In the simulations of the recorded spectra, the influence of geometrical configuration changes of the diagnostic system (pinhole size, detector size, location of each diagnostic component), of the timing of data collection, as well as of the type and thickness of filters are being investigated. The atomic processes of free-free (bremsstrahlung), free-bound (recombination radiation), and bound-bound emission (line radiation) are considered. For the impurities fractional abundancies of 3% carbon (C), 0.5% oxygen (O) and 0.002% iron (Fe) are taken into account. Information about the number of photons which reach the detector and the current generated inside the detector is given. It is shown that the distance between pinhole and detector has a larger impact on the registered spectra (intensity and total number of photons) than the distance between plasma and pinhole. Based on the results of the simulations, the expected optimal positions of the individual components (pinholes, detectors) were defined for the PHA W7-X diagnostic system. A shorter version of this contribution is due to be published in PoS at: 1st EPS conference on Plasma Diagnostics

  3. A high resolution small animal radiation research platform (SARRP) with x-ray tomographic guidance capabilities

    Science.gov (United States)

    Wong, John; Armour, Elwood; Kazanzides, Peter; Iordachita, Iulian; Tryggestad, Erik; Deng, Hua; Matinfar, Mohammad; Kennedy, Christopher; Liu, Zejian; Chan, Timothy; Gray, Owen; Verhaegen, Frank; McNutt, Todd; Ford, Eric; DeWeese, Theodore L.

    2008-01-01

    Purpose To demonstrate the CT imaging, conformal irradiation and treatment planning capabilities of a small animal radiation research platform (SARRP). Methods The SARRP employs a dual-focal spot, constant voltage x-ray source mounted on a gantry with a source-to-isocenter distance of 35 cm. Gantry rotation is limited to 120° from vertical. Eighty to 100 kVp x-rays from the smaller 0.4 mm focal spot are used for imaging. Both 0.4 mm and 3.0 mm focal spots operate at 225 kVp for irradiation. Robotic translate/rotate stages are used to position the animal. Cone-beam (CB) CT imaging is achieved by rotating the horizontal animal between the stationary x-ray source and a flat-panel detector. Radiation beams range from 0.5 mm in diameter to (60 × 60) mm2. Dosimetry is measured with radio-chromic films. Monte Carlo dose calculations are employed for treatment planning. The combination of gantry and robotic stage motions facilitate conformal irradiation. Results The SARRP spans 3 ft × 4 ft × 6 ft (WxLxH). Depending on filtration, the isocenter dose outputs at 1 cm depth in water range from 22 to 375 cGy/min from the smallest to the largest radiation fields. The 20% to 80% dose fall-off spans 0.16 mm. CBCT with (0.6 × 0.6 × 0.6) mm3 voxel resolution is acquired with less than 1 cGy. Treatment planning is performed at sub-mm resolution. Conclusions The capability of the SARRP to deliver highly focal beams to multiple animal model systems provides new research opportunities that more realistically bridge laboratory research and clinical translation. PMID:18640502

  4. Extracting the redox orbitals in Li battery materials with high-resolution x-ray compton scattering spectroscopy.

    Science.gov (United States)

    Suzuki, K; Barbiellini, B; Orikasa, Y; Go, N; Sakurai, H; Kaprzyk, S; Itou, M; Yamamoto, K; Uchimoto, Y; Wang, Yung Jui; Hafiz, H; Bansil, A; Sakurai, Y

    2015-02-27

    We present an incisive spectroscopic technique for directly probing redox orbitals based on bulk electron momentum density measurements via high-resolution x-ray Compton scattering. Application of our method to spinel Li_{x}Mn_{2}O_{4}, a lithium ion battery cathode material, is discussed. The orbital involved in the lithium insertion and extraction process is shown to mainly be the oxygen 2p orbital. Moreover, the manganese 3d states are shown to experience spatial delocalization involving 0.16±0.05 electrons per Mn site during the battery operation. Our analysis provides a clear understanding of the fundamental redox process involved in the working of a lithium ion battery.

  5. The x-ray emission spectra of multicharged xenon ions in a gas puff laser-produced plasma

    Energy Technology Data Exchange (ETDEWEB)

    Skobelev, I.Yu.; Dyakin, V.M.; Faenov, A.Ya. [Multicharged Ion Spectra Data Center, VNIIFTRI, Mendeleevo (Russian Federation); Bartnik, A.; Fiedorowicz, H.; Jarocki, R.; Kostecki, J.; Szczurek, M. [Institute of Optoelectronics, Military University of Technology, Warsaw (Poland); Biemont, E. [Institut de Physique Nucleaire Experimentale, Universite de Liege, Liege (Belgium); Astrophysique et Spectroscopie, Universite de Mons-Hainaut, Mons (Belgium); Quinet, P. [Astrophysique et Spectroscopie, Universite de Mons-Hainaut, Mons (Belgium); Nilsen, J. [Lawrence Livermore National Laboratory, Livermore, CA (United States); Behar, E.; Doron, R.; Mandelbaum, P.; Schwob, J.L. [Racah Institute of Physics, Hebrew University of Jerusalem, Jerusalem (Israel)

    1999-01-14

    Emission spectra of multicharged xenon ions produced by a laser gas puff are observed with high spectral resolution in the 8.5-9.5 and 17-19 A wavelength ranges. Three different theoretical methods are employed to obtain 3l-n'l'(n' = 4 to 10) wavelengths and Einstein coefficients for Ni-like Xe{sup 26+}. For the 3d-4p transitions, very good agreement is found between the experimental wavelengths and the various theoretical wavelengths. These accurate energy level measurements can be useful for studying the Ni-like xenon x-ray laser scheme. On the other hand, several intense spectral lines could not be identified as 3l-n'l' lines of Ni-like xenon, despite the very good agreement between the wavelengths and Einstein coefficients calculated for these transitions using the three different methods. (author)

  6. Measurement of position dependence of spectral distribution in primary X-ray beam of CT system using compton spectroscopy

    International Nuclear Information System (INIS)

    Matsumoto, Masao; Maeda, Koji; Maeda, Koji

    2005-01-01

    Our purpose is to acquire the diagnostic x-ray spectra of the CT system easily under clinical conditions by Compton scatter spectroscopy using a high resolution Schottky CdTe detector recently developed and to estimate the quality and quantity of these spectra compared the relative exposure measured using an ionization chamber with curves measured by the reconstructed spectra. Although the spectral broadening and the fluctuation were slightly shown, the errors of the relative exposure were under 10%. Though the experimental arrangement of this method is so easy and reconstructed algorithm is simple, these results suggested that this method is little influenced by the variation of dose rates or property of the incident x rays. We therefore propose that the Compton scatter spectroscopy with the newly developed Schottky CdTe detector is suitable for measuring the diagnostic x-ray spectra of the CT system under the clinical conditions and useful for quality assurance and quality control of the clinical x-ray CT system. (author)

  7. The performance of the curved grid gas proportional scintillation counter in X-ray spectrometry

    International Nuclear Information System (INIS)

    Santos, J.M.F. dos; Bento, A.C.S.S.M.; Conde, C.A.N.

    1994-01-01

    The performance of a curved grid gas proportional scintillation counter filled with xenon at 1100 mbar and having a 25 mm diameter window is evaluated for X-rays in the 1-11 keV energy range. Energy resolutions of 8.0% were obtained for a 5.9 keV parallel X-ray beam entering the detector through the full size window. The variation of the energy resolution with the X-ray energy is studied and X-ray fluorescence spectra for samples like industrial coal, painted porcelain and car lubrication oil, are presented. (orig.)

  8. Contribution of x-ray topography and high-resolution diffraction to the study of defects in SiC

    International Nuclear Information System (INIS)

    Dudley, Michael; Huang Xianrong; Vetter, William M

    2003-01-01

    A short review is presented of the various synchrotron white beam x-ray topography (SWBXT) imaging techniques developed for characterization of silicon carbide (SiC) crystals and thin films. These techniques, including back-reflection topography, reticulography, transmission topography, and a set of section topography techniques, are demonstrated to be particularly powerful for imaging hollow-core screw dislocations (micropipes) and closed-core threading screw dislocations, as well as other defects, in SiC. The geometrical diffraction mechanism commonly underlying these imaging processes is emphasized for understanding the nature and origins of these defects. Also introduced is the application of SWBXT combined with high-resolution x-ray diffraction techniques to complete characterization of 3C/4H or 3C/6H SiC heterostructures, including polytype identification, 3C variant mapping, and accurate lattice mismatch measurements

  9. SU-F-I-76: Fluoroscopic X-Ray Beam Profiles for Spectra Incorporating Copper Filtration

    Energy Technology Data Exchange (ETDEWEB)

    Wunderle, K [Cleveland Clinic Foundation, Cleveland, OH (United States); Wayne State University School of Medicine, Detroit, MI (United States); Godley, A; Shen, Z; Dong, F [Cleveland Clinic Foundation, Cleveland, OH (United States); Rakowski, J [Wayne State University School of Medicine, Detroit, MI (United States)

    2016-06-15

    Purpose: The purpose of this investigation is to characterize and quantify X-ray beam profiles for fluoroscopic x-ray beam spectra incorporating spectral (copper) filtration. Methods: A PTW (Freiburg, Germany) type 60016 silicon diode detector and PTW MP3 water tank were used to measure X-ray beam profiles for 60, 80, 100 and 120 kVp x-ray beams at five different copper filtration thicknesses ranging from 0–0.9 mm at 22 and 42 cm fields of view and depths of 1, 5, and 10 cm in both the anode-cathode axis (inplane) and cross-plane directions. All measurements were acquired on a Siemens (Erlangen, Germany) Artis ZeeGo fluoroscope inverted from the typical orientation providing an x-ray beam originating from above the water surface with the water level set at 60 cm from the focal spot. Results: X-ray beam profiles for beam spectra without copper filtration compared well to previously published data by Fetterly et al. [Med Phys, 28, 205 (2001)]. Our data collection benefited from the geometric orientation of the fluoroscope, providing a beam perpendicular to the tank water surface, rather than through a thin side wall as did the previously mentioned study. Profiles for beams with copper filtration were obtained which have not been previously investigated and published. Beam profiles in the anode-cathode axis near the surface and at lower x-ray energy exhibited substantial heel effect, which became less pronounced at greater depth. At higher energy with copper filtration in the beam, the dose falloff out-of-field became less pronounced, as would be anticipated given higher scatter photon energy. Conclusion: The x-ray beam profile data for the fluoroscopic x-ray beams incorporating copper filtration are intended for use as reference data for estimating doses to organs or soft tissue, including fetal dose, involving similar beam qualities or for comparison with mathematical models.

  10. Columbia University OSO-8 instrument for stellar and solar X-ray spectroscopy and polarimetry

    Energy Technology Data Exchange (ETDEWEB)

    Wolff, R S [Columbia Univ., New York (USA). Columbia Astrophysics Lab.

    1976-08-01

    A spectrometer and a polarimeter consisting of large-area panels of mosaic crystals have been constructed and prepared for use in the OSO-8 satellite. The instrumentation is planned for study of stellar and solar X-ray spectra between 1.8-8 keV and stellar X-ray polarization at 2.6 keV. Aspects of the design which enable the instrument to make measurements of the diverse range of stellar and solar phenomena are described. Some of the unique features, such as high sensitivity, high temporal resolution, and spectral range, are discussed. The applicability of the spectrometer and polarimeter to various current problems in X-ray astronomy is considered.

  11. Wave-dispersive x-ray spectrometer for simultaneous acquisition of several characteristic lines based on strongly and accurately shaped Ge crystal

    International Nuclear Information System (INIS)

    Hayashi, Kouichi; Nakajima, Kazuo; Fujiwara, Kozo; Nishikata, Susumu

    2008-01-01

    Si and Ge are widely used as analyzing crystals for x-rays. Drastic and accurate shaping of Si or Ge gives significant advance in the x-ray field, although covalently bonded Si or Ge crystals have long been believed to be not deformable to various shapes. Recently, we developed a deformation technique for obtaining strongly and accurately shaped Si or Ge wafers of high crystal quality, and the use of the deformed wafer made it possible to produce fine-focused x-rays. In the present study, we prepared a cylindrical Ge wafer with a radius of curvature of 50 mm, and acquired fluorescent x-rays simultaneously from four elements by combining the cylindrical Ge wafer with a position-sensitive detector. The energy resolution of the x-ray fluorescence spectrum was as good as that obtained using a flat single crystal, and its gain was over 100. The demonstration of the simultaneous acquisition of high-resolution x-ray fluorescence spectra indicated various possibilities of x-ray spectrometry, such as one-shot x-ray spectroscopy and highly efficient wave-dispersive x-ray spectrometers

  12. Present status and future prospect of x-ray microscopes. Is it possible to realize x-ray 1 nm imaging?

    International Nuclear Information System (INIS)

    Aoki, Sadao

    2010-01-01

    High resolution X-ray imaging has been developed by using various optical elements and optical systems. In the soft X-ray region (∼3 nm) about 20 nm spatial resolution has been obtained, while in the hard X-ray (∼0.1 nm) about 50 nm. In the research frontier the spatial resolution better than 10 nm has been reported. The possibility to approach 1 nm spatial resolution is presented. (author)

  13. Studies of the X-ray absorption spectra of some methylcyano esters

    International Nuclear Information System (INIS)

    Takahashi, Osamu; Saito, Ko; Mitani, Masaki; Yoshida, Hiroaki; Tahara, Fumitaka; Sunami, Tetsuji; Waki, Keiichiro; Senba, Yasunori; Hiraya, Atsunari; Pettersson, Lars G.M.

    2005-01-01

    Density functional theory (DFT) has been applied to simulate core-excited photoabsorption spectra for some methylcyano esters within a transition potential (TP) framework. Our calculations for methylcyano formate at the N and O K-edges are consistent with previous experimental spectra. For methylcyano acetate the photoabsorption spectra at the N and O K-edges were reinvestigated experimentally. Contrary to the previous experiment, only one main peak was observed at the N K-edge and this peak was assigned to N(1s) ->π* excitation. This result was supported by our theoretical calculations. The general trends in the X-ray absorption spectra and the site-specific bond scission of methylcyano esters at the N and O K-edges are also discussed

  14. Development of hard X-ray spectrometer with high time resolution on the J-TEXT tokamak

    Energy Technology Data Exchange (ETDEWEB)

    Ma, T.K.; Chen, Z.Y., E-mail: zychen@hust.edu.cn; Huang, D.W.; Tong, R.H.; Yan, W.; Wang, S.Y.; Dai, A.J.; Wang, X.L.

    2017-06-01

    A hard X-ray (HXR) spectrometer has been developed to study the runaway electrons during the sawtooth activities and during the runaway current plateau phase on the J-TEXT tokamak. The spectrometer system contains four NaI scintillator detectors and a multi-channel analyzer (MCA) with 0.5 ms time resolution. The dedicated peak detection circuit embedded in the MCA provides a pulse height analysis at count rate up to 1.2 million counts per second (Mcps), which is the key to reach the high time resolution. The accuracy and reliability of the system have been verified by comparing with the hardware integrator of HXR flux. The temporal evolution of HXR flux in different energy ranges can be obtained with high time resolution by this dedicated HXR spectrometer. The response of runaway electron transport with different energy during the sawtooth activities can be studied. The energy evolution of runaway electrons during the plateau phase of runaway current can be obtained. - Highlights: • A HXR spectrometer with high time resolution has been developed on J-TEXT tokamak. • The response of REs transport during the sawtooth activities can be investigated. • The energy evolution of REs following the disruptions can be monitored.

  15. X-ray scattering measurements from thin-foil x-ray mirrors

    DEFF Research Database (Denmark)

    Christensen, Finn Erland; BYRNAK, BP; Hornstrup, Allan

    1992-01-01

    Thin foil X-ray mirrors are to be used as the reflecting elements in the telescopes of the X-ray satellites Spectrum-X-Gamma (SRG) and ASTRO-D. High resolution X-ray scattering measurements from the Au coated and dip-lacquered Al foils are presented. These were obtained from SRG mirrors positioned...... in a test quadrant of the telescope structure and from ASTRO-D foils held in a simple fixture. The X-ray data is compared with laser data and other surface structure data such as STM, atomic force microscopy (AFM), TEM, and electron micrography. The data obtained at Cu K-alpha(1), (8.05 keV) from all...

  16. 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.

  17. Time-resolved X-ray PIV technique for diagnosing opaque biofluid flow with insufficient X-ray fluxes.

    Science.gov (United States)

    Jung, Sung Yong; Park, Han Wook; Kim, Bo Heum; Lee, Sang Joon

    2013-05-01

    X-ray imaging is used to visualize the biofluid flow phenomena in a nondestructive manner. A technique currently used for quantitative visualization is X-ray particle image velocimetry (PIV). Although this technique provides a high spatial resolution (less than 10 µm), significant hemodynamic parameters are difficult to obtain under actual physiological conditions because of the limited temporal resolution of the technique, which in turn is due to the relatively long exposure time (~10 ms) involved in X-ray imaging. This study combines an image intensifier with a high-speed camera to reduce exposure time, thereby improving temporal resolution. The image intensifier amplifies light flux by emitting secondary electrons in the micro-channel plate. The increased incident light flux greatly reduces the exposure time (below 200 µs). The proposed X-ray PIV system was applied to high-speed blood flows in a tube, and the velocity field information was successfully obtained. The time-resolved X-ray PIV system can be employed to investigate blood flows at beamlines with insufficient X-ray fluxes under specific physiological conditions. This method facilitates understanding of the basic hemodynamic characteristics and pathological mechanism of cardiovascular diseases.

  18. High resolution γ-ray spectroscopy: The first 85 years

    International Nuclear Information System (INIS)

    Deslattes, R.D.

    2000-01-01

    This opening review attempts to follow the main trends in crystal diffraction spectrometry of nuclear γ rays from its 1914 beginning in Rutherford's laboratory to the ultra-high resolution instrumentation realized in the current generation of spectrometers at the Institute Laue Langeven (ILL). The authors perspective is that of an instrumentalist hoping to convey a sense of intellectual debt to a number of predecessors, each of whom realized a certain elegance in making the tools that have enabled much good science, including that to which the remainder of this workshop is dedicated. This overview follows some of the main ideas along a trajectory toward higher resolution at higher energies, thereby enabling not only the disentangling of dense spectra, but also allowing detailed study of aspects of spectral profiles sensitive to excited state lifetimes and interatomic potentials. The parallel evolution toward increasing efficiency while preserving needed resolution is also an interesting story of artful compromise that should not be neglected. Finally, it is the robustness of the measurement chain connecting γ-ray wavelengths with optical wave-lengths associated with the Rydberg constant that only recently has allowed γ-ray data to contribute to determine of particle masses and fundamental constants, as will be described in more detail in other papers from this workshop

  19. Magnetically-coupled microcalorimeter arrays for x-ray astrophysics with sub-eV spectral resolution and large format capability Project

    Data.gov (United States)

    National Aeronautics and Space Administration — "We propose to develop a revolutionary x-ray camera for astrophysical imaging spectroscopy. High-resolution x-ray spectroscopy is a powerful tool for studying the...

  20. A high resolution reflecting crystal spectrometer to measure 3 keV pionic hydrogen and deuterium X-rays

    International Nuclear Information System (INIS)

    Badertscher, A.; Bogdan, M.; Goudsmit, P.F.A.; Knecht, L.; Leisi, H.J.; Schroeder, H.C.; Sigg, D.; Zhao, Z.G.; Chatellard, D.; Egger, J.P.; Jeannet, E.; Aschenauer, E.C.; Gabathuler, K.; Simons, L.M.; Rusi El Hassani, A.J.

    1993-01-01

    A reflecting crystal spectrometer consisting of three cylindrically bent quartz (110) crystals is described. It was designed to measure the 3 keV K β X-rays from pionic hydrogen and deuterium. Charge coupled devices (CCDs) were used as X-ray detectors. Projecting the reflexes of all three crystals on one common focus, an instrumental energy resolution below 1 eV was obtained at an energy of 2.9 keV. (orig.)

  1. Modeling of X-ray Images and Energy Spectra Produced by Stepping Lightning Leaders

    Science.gov (United States)

    Xu, Wei; Marshall, Robert A.; Celestin, Sebastien; Pasko, Victor P.

    2017-11-01

    Recent ground-based measurements at the International Center for Lightning Research and Testing (ICLRT) have greatly improved our knowledge of the energetics, fluence, and evolution of X-ray emissions during natural cloud-to-ground (CG) and rocket-triggered lightning flashes. In this paper, using Monte Carlo simulations and the response matrix of unshielded detectors in the Thunderstorm Energetic Radiation Array (TERA), we calculate the energy spectra of X-rays as would be detected by TERA and directly compare with the observational data during event MSE 10-01. The good agreement obtained between TERA measurements and theoretical calculations supports the mechanism of X-ray production by thermal runaway electrons during the negative corona flash stage of stepping lightning leaders. Modeling results also suggest that measurements of X-ray bursts can be used to estimate the approximate range of potential drop of lightning leaders. Moreover, the X-ray images produced during the leader stepping process in natural negative CG discharges, including both the evolution and morphological features, are theoretically quantified. We show that the compact emission pattern as recently observed in X-ray images is likely produced by X-rays originating from the source region, and the diffuse emission pattern can be explained by the Compton scattering effects.

  2. Colloquium: Femtosecond x-ray crystallography

    International Nuclear Information System (INIS)

    Rousse, Antoine; Rischel, Christian; Gauthier, Jean-Claude

    2001-01-01

    This article gives an overview of recent x-ray diffraction experiments with time resolutions down to 10 -13 s. The scientific motivation behind the development is outlined, using examples from solid state physics and biology. The ultrafast resolution may be provided either by fast detectors or short x-ray pulses, and the limitations of both techniques are discussed on the basis of state of the art experiments. In particular, it is shown that with present designs, high time resolution reduces the structural information attainable with high spatial resolution, thereby limiting feasible experiments on the ultrashort time-scale. The first experiment showing subpicosecond conformation changes was recently achieved with simple solids using an ultrafast laser-produced plasma x-ray source. The principles of this experiment are described in detail

  3. Simbol-X: Imaging The Hard X-ray Sky with Unprecedented Spatial Resolution and Sensitivity

    Science.gov (United States)

    Tagliaferri, Gianpiero; Simbol-X Joint Scientific Mission Group

    2009-01-01

    Simbol-X is a hard X-ray mission, with imaging capability in the 0.5-80 keV range. It is based on a collaboration between the French and Italian space agencies with participation of German laboratories. The launch is foreseen in late 2014. It relies on a formation flight concept, with two satellites carrying one the mirror module and the other one the focal plane detectors. The mirrors will have a 20 m focal length, while the two focal plane detectors will be put one on top of the other one. This combination will provide over two orders of magnitude improvement in angular resolution and sensitivity in the hard X-ray range with respect to non-focusing techniques. The Simbol-X revolutionary instrumental capabilities will allow us to elucidate outstanding questions in high energy astrophysics such as those related to black-holes accretion physics and census, and to particle acceleration mechanisms. We will give an overall description of the mission characteristics, performances and scientific objectives.

  4. Dynamics of hot spots in the DPF-78 plasma focus from x-ray spectra and REB emission

    International Nuclear Information System (INIS)

    Schmidt, H.; Wang, X.X.

    1995-01-01

    The X-ray emission from hot spots in the plasma focus DPF-78 was investigated with the help of two X-ray quartz crystal spectrometers of the Johann type and a 4 fold magnifying X-ray pinhole camera. In the experiments the working gas was chosen to be 300 Pa deuterium with 20 Pa argon admixture. X-ray spectra in the wavelength range from 3.55 angstrom to 4.0 angstrom, including H-like and He-like Argon lines, were recorded on Kodak DEF-2 film. From the spatially resolved spectra recorded side-on, a relative spectral shift between different hot spots of the same shot was often observed. The shift could be attributed to the Doppler shift. From spectral characteristics such as intensities and FWHM of Ar resonant and intercombination lines electron densities of up to 3 x 10 27 m -3 were determined. Radial dimensions of the hot spots ranging from about 140 microm to 300 microm were found from pinhole pictures applying the penumbra method. Usually two pulses of relativistic electron beams were observed using Cherenkov detectors in a magnetic spectrometer. The energy of the first pulse, which was emitted at the time of maximum compression, was higher than that of the second pulse. The measured FWHM of the REB pulses ranges from 3 ns to about 10 ns. The characteristics of the time-integrated X-ray spectra and the time resolved REB spectra and their dependence on the composition of the filling gas are discussed

  5. ISMabs: A COMPREHENSIVE X-RAY ABSORPTION MODEL FOR THE INTERSTELLAR MEDIUM

    Energy Technology Data Exchange (ETDEWEB)

    Gatuzz, E.; Mendoza, C. [Centro de Física, Instituto Venezolano de Investigaciones Científicas (IVIC), P.O. Box 20632, Caracas 1020A (Venezuela, Bolivarian Republic of); García, J. [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA, 02138 (United States); Kallman, T. R. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Gorczyca, T. W., E-mail: egatuzz@ivic.gob.ve, E-mail: claudio@ivic.gob.ve, E-mail: javier@head.cfa.harvard.edu, E-mail: timothy.r.kallman@nasa.gov, E-mail: thomas.gorczyca@wmich.edu [Department of Physics, Western Michigan University, Kalamazoo, MI 49008 (United States)

    2015-02-10

    We present an X-ray absorption model for the interstellar medium, to be referred to as ISMabs, that takes into account both neutral and ionized species of cosmically abundant elements, and includes the most accurate atomic data available. Using high-resolution spectra from eight X-ray binaries obtained with the Chandra High Energy Transmission Grating Spectrometer, we proceed to benchmark the atomic data in the model particularly in the neon K-edge region. Compared with previous photoabsorption models, which solely rely on neutral species, the inclusion of ions leads to improved spectral fits. Fit parameters comprise the column densities of abundant contributors that allow direct estimates of the ionization states. ISMabs is provided in the appropriate format to be implemented in widely used X-ray spectral fitting packages such as XSPEC, ISIS, and SHERPA.

  6. Natural widths and Coster-Kronig transitions of L X-ray spectra in elements between Pd and Sb

    International Nuclear Information System (INIS)

    Sakakura, Shusuke; Oohashi, Hirofumi; Ito, Yoshiaki; Tochio, Tatsunori; Vlaicu, Aurel M.; Yoshikawa, Hideki; Ikenaga, Eiji; Kobayashi, Keisuke

    2006-01-01

    The Lα and Lβ X-ray emission spectra in the elements between Pd (Z=46) and Sb (Z=51) were measured using a high-resolution double-crystal vacuum spectrometer. The relative intensities of satellite structures, which originate in L 1 L 3 M 4,5 Coster-Kronig transitions, were estimated to that of each diagram line, and compared with calculated values. According to the work of Chen et al. [1977a. Theoretical L-shell Coster-Kronig energies 11≤Z≤103. At. Data Nucl. Data Tables 19, 97-151], Salgueiro et al. [1987. J. Phys. (Paris) 48 Colloq. C9, 609] and Vlaicu et al. [1998. Investigation of the 74W L emission spectra and satellites. Phys. Rev. A 58, 3544] L 1 L 3 M 4 Coster-Kronig transition is forbidden for 50≤Z≤77, and L 1 L 3 M 5 Coster-Kronig transition is forbidden for 50≤Z≤73. The results suggest that L 1 L 3 M 4,5 Coster-Kronig transitions may be allowed even for Sn (Z=50) and Sb (Z=51)

  7. Identification of Hard X-ray Sources in Galactic Globular Clusters: Simbol-X Simulations

    Science.gov (United States)

    Servillat, M.

    2009-05-01

    Globular clusters harbour an excess of X-ray sources compared to the number of X-ray sources in the Galactic plane. It has been proposed that many of these X-ray sources are cataclysmic variables that have an intermediate magnetic field, i.e. intermediate polars, which remains to be confirmed and understood. We present here several methods to identify intermediate polars in globular clusters from multiwavelength analysis. First, we report on XMM-Newton, Chandra and HST observations of the very dense Galactic globular cluster NGC 2808. By comparing UV and X-ray properties of the cataclysmic variable candidates, the fraction of intermediate polars in this cluster can be estimated. We also present the optical spectra of two cataclysmic variables in the globular cluster M 22. The HeII (4868 Å) emission line in these spectra could be related to the presence of a magnetic field in these objects. Simulations of Simbol-X observations indicate that the angular resolution is sufficient to study X-ray sources in the core of close, less dense globular clusters, such as M 22. The sensitivity of Simbol-X in an extended energy band up to 80 keV will allow us to discriminate between hard X-ray sources (such as magnetic cataclysmic variables) and soft X-ray sources (such as chromospherically active binaries).

  8. Applications of phase-contrast x-ray imaging to medicine using an x-ray interferometer

    Science.gov (United States)

    Momose, Atsushi; Yoneyama, Akio; Takeda, Tohoru; Itai, Yuji; Tu, Jinhong; Hirano, Keiichi

    1999-10-01

    We are investigating possible medical applications of phase- contrast X-ray imaging using an X-ray interferometer. This paper introduces the strategy of the research project and the present status. The main subject is to broaden the observation area to enable in vivo observation. For this purpose, large X-ray interferometers were developed, and 2.5 cm X 1.5 cm interference patterns were generated using synchrotron X-rays. An improvement of the spatial resolution is also included in the project, and an X-ray interferometer designed for high-resolution phase-contrast X-ray imaging was fabricated and tested. In parallel with the instrumental developments, various soft tissues are observed by phase- contrast X-ray CT to find correspondence between the generated contrast and our histological knowledge. The observation done so far suggests that cancerous tissues are differentiated from normal tissues and that blood can produce phase contrast. Furthermore, this project includes exploring materials that modulate phase contrast for selective imaging.

  9. Hard X-ray quantum optics in thin films nanostructures

    Energy Technology Data Exchange (ETDEWEB)

    Haber, Johann Friedrich Albert

    2017-05-15

    This thesis describes quantum optical experiments with X-rays with the aim of reaching the strong-coupling regime of light and matter. We make use of the interaction which arises between resonant matter and X-rays in specially designed thin-film nanostructures which form X-ray cavities. Here, the resonant matter are Tantalum atoms and the Iron isotope {sup 57}Fe. Both limit the number of modes available to the resonant atoms for interaction, and enhances the interaction strength. Thus we have managed to observe a number of phenomena well-known in quantum optics, which are the building blocks for sophisticated applications in e.g. metrology. Among these are the strong coupling of light and matter and the concurrent exchange of virtual photons, often called Rabi oscillations. Furthermore we have designed and tested a type of cavity hitherto unused in X-ray optics. Finally, we develop a new method for synchrotron Moessbauer spectroscopy, which not only promises to yield high-resolution spectra, but also enables the retrieval of the phase of the scattered light. The results open new avenues for quantum optical experiments with X-rays, particularly with regards to the ongoing development of high-brilliance X-ray free-electron lasers.

  10. Hard X-ray quantum optics in thin films nanostructures

    International Nuclear Information System (INIS)

    Haber, Johann Friedrich Albert

    2017-05-01

    This thesis describes quantum optical experiments with X-rays with the aim of reaching the strong-coupling regime of light and matter. We make use of the interaction which arises between resonant matter and X-rays in specially designed thin-film nanostructures which form X-ray cavities. Here, the resonant matter are Tantalum atoms and the Iron isotope "5"7Fe. Both limit the number of modes available to the resonant atoms for interaction, and enhances the interaction strength. Thus we have managed to observe a number of phenomena well-known in quantum optics, which are the building blocks for sophisticated applications in e.g. metrology. Among these are the strong coupling of light and matter and the concurrent exchange of virtual photons, often called Rabi oscillations. Furthermore we have designed and tested a type of cavity hitherto unused in X-ray optics. Finally, we develop a new method for synchrotron Moessbauer spectroscopy, which not only promises to yield high-resolution spectra, but also enables the retrieval of the phase of the scattered light. The results open new avenues for quantum optical experiments with X-rays, particularly with regards to the ongoing development of high-brilliance X-ray free-electron lasers.

  11. A high spatial resolution X-ray and Hα study of hot gas in the halos of star-forming disk galaxies -- testing feedback models

    Science.gov (United States)

    Strickland, D. K.; Heckman, T. M.; Colbert, E. J. M.; Hoopes, C. G.; Weaver, K. A.

    2002-12-01

    We present arcsecond resolution Chandra X-ray and ground-based optical Hα imaging of a sample of ten edge-on star-forming disk galaxies (seven starburst and three ``normal'' spiral galaxies), a sample which covers the full range of star-formation intensity found in disk galaxies. The X-ray observations make use of the unprecented spatial resolution of the Chandra X-ray observatory to robustly remove X-ray emission from point sources, and hence obtain the X-ray properties of the diffuse thermal emission alone. This data has been combined with existing, comparable-resolution, ground-based Hα imaging. We compare these empirically-derived diffuse X-ray properties with various models for the generation of hot gas in the halos of star-forming galaxies: supernova feedback-based models (starburst-driven winds, galactic fountains), cosmologically-motivated accretion of the IGM and AGN-driven winds. SN feedback models best explain the observed diffuse X-ray emission. We then use the data to test basic, but fundamental, aspects of wind and fountain theories, e.g. the critical energy required for disk "break-out." DKS is supported by NASA through Chandra Postdoctoral Fellowship Award Number PF0-10012.

  12. X-ray spectral meter of high voltages for X-ray apparatuses

    International Nuclear Information System (INIS)

    Zubkov, I.P.; Larchikov, Yu.V.

    1993-01-01

    Design of the X-ray spectral meter of high voltages (XRSMHV) for medical X-ray apparatuses permitting to conduct the voltage measurements without connection to current circuits. The XRSMHV consists of two main units: the detector unit based on semiconductor detector and the LP4900B multichannel analyzer (Afora, Finland). The XRSMYV was tested using the pilot plant based on RUM-20 X-ray diagnostic apparatus with high-voltage regulator. It was shown that the developed XRSMHV could be certify in the range of high constant voltages form 40 up to 120 kV with the basic relative error limits ±0.15%. The XRSMHV is used at present as the reference means for calibration of high-voltage medical X-ray equipment

  13. Programme in Basic-Applesoft language for microcomputer to analyse pulse spectra from a high-resolution gamma ray system

    International Nuclear Information System (INIS)

    Nascimento Filho, V.F. do; Marques, D.A.; Pessenda, L.C.R.; Barros Ferraz, E.S. de; Nadai, E.A. de; Sao Paulo Univ., Piracicaba

    1988-01-01

    A programme in BASIC-Applesoft language has been developed for low cost microcomputer to analyze spectra from a high-resolution gamma-ray system (high-purity germanium and 4096 channels analyzer). Data is received by the microcomputer directly from analyzer (4 min) or keyboard and shown on video (4 min) or printed (9,7 min). Graphics of parts of the spectrum can be either shown on video (a cursor is used to identify peaks) or printed. The peak search, centroid, energy, net photopeak area, standard deviation and relative standard deviation are included in the programme (5 min), besides filing of data in flexible disk (1,3 min). The programme was used on a 12 h real-time detection in Marinelli beaker of 1265 g sandy soil sample (Ref-Yellow Latosol, 0-3 cm layer). Thirty-one peaks from U-238 and Th-232 daughters were analyzed (rsd less than 20%), besides natural K-40 and artificial Cs-137, from fallout. (author) [pt

  14. The Highest Resolution X-ray View of the Nuclear Region of NGC 4151

    Science.gov (United States)

    Wang, Junfeng; Fabbiano, G.; Karovska, M.; Elvis, M.; Risaliti, G.; Zezas, A.; Mundell, C. G.

    2009-09-01

    We report high resolution imaging of the nucleus of the Seyfert 1 galaxy NGC 4151 obtained with a 50 ks Chandra HRC observation. The HRC image resolves the emission on spatial scales of 0.5 arcsec (30 pc), showing an extended X-ray morphology overall consistent with the narrow line region seen in optical line emission. Removal of the bright point-like nuclear source and image deconvolution technique both reveal X-ray enhancements that closely match the substructures seen in the HST [OIII] image and prominent knots in the radio jet. We find that most of the NLR clouds in NGC 4151 have [OIII] to soft X-ray ratio consistent with the values observed in NLRs of some Seyfert 2 galaxies, which indicates a uniform ionization parameter even at large radii and a density dependence ∝ r^{-2} as expected in the disk wind scenario. We examine various X-ray emission mechanisms of the radio jet and consider thermal emission from interaction between radio outflow and the NLR clouds the most probable origin for the X-ray emission associated with the jet.

  15. Numerical simulation study for atomic-resolution x-ray fluorescence holography

    International Nuclear Information System (INIS)

    Xie Honglan; Gao Hongyi; Chen Jianwen; Xiong Shisheng; Xu Zhizhan; Wang Junyue; Zhu Peiping; Xian Dingchang

    2003-01-01

    Based on the principle of x-ray fluorescence holography, an iron single crystal model of a body-centred cubic lattice is numerically simulated. From the fluorescence hologram produced numerically, the Fe atomic images were reconstructed. The atomic images of the (001), (100), (010) crystallographic planes were consistent with the corresponding atomic positions of the model. The result indicates that one can obtain internal structure images of single crystals at atomic-resolution by using x-ray fluorescence holography

  16. Imaging of exploding wire plasmas by high-luminosity monochromatic X-ray backlighting using an X-pinch radiation source

    Energy Technology Data Exchange (ETDEWEB)

    Pikuz, S A; Shelkovenko, T A; Romanova, V M [Russian Academy of Sciences, Moscow (Russian Federation). P.N. Lebedev Physical Inst.; Hammer, D A [Cornell Univ., Ithaca, NY (United States). Laboratory of Plasma Studies; Faenov, A Ya; Pikuz, T A [VNIIFTRI, Mendeleevo (Russian Federation). Multicharged Ions Spectral Data Center

    1997-12-31

    A new diagnostic method for dense plasmas, monochromatic x-ray backlighting, is described. In this method, shadow images of a bright, dense plasma can be obtained with high spatial resolution using monochromatic radiation from a separate plasma, permitting a major reduction in the required backlighting source power. The object plasma is imaged utilizing spherically bent mica crystals as the x-ray optical elements. Images of test objects obtained using x-ray radiation having different photon energies are presented. Shadow images of exploding Al wire plasmas in the ls{sup 2}-1s3p line radiation of He-like Al XII are also shown. Spatial resolution as fine as 4 {mu}m is demonstrated. The scheme described is useful for backlighting extended high density plasmas, and could be a less costly alternative to using X-ray lasers for such purposes. (author). 7 figs., 10 refs.

  17. Novel X-ray telescopes for wide-field X-ray monitoring

    International Nuclear Information System (INIS)

    Hudec, R.; Inneman, A.; Pina, L.; Sveda, L.

    2005-01-01

    We report on fully innovative very wide-field of view X-ray telescopes with high sensitivity as well as large field of view. The prototypes are very promising, allowing the proposals for space projects with very wide-field Lobster-eye X-ray optics to be considered. The novel telescopes will monitor the sky with unprecedented sensitivity and angular resolution of order of 1 arcmin. They are expected to contribute essentially to study and to understand various astrophysical objects such as AGN, SNe, Gamma-ray bursts (GRBs), X-ray flashes (XRFs), galactic binary sources, stars, CVs, X-ray novae, various transient sources, etc. The Lobster optics based X-ray All Sky Monitor is capable to detect around 20 GRBs and 8 XRFs yearly and this will surely significantly contribute to the related science

  18. 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.

  19. Calculations of magnetic x-ray dichroism in the 3d absorption spectra of rare-earth compounds

    NARCIS (Netherlands)

    GOEDKOOP, JB; THOLE, BT; VANDERLAAN, G; SAWATZKY, GA; DEGROOT, FMF; FUGGLE, JC; de Groot, Frank|info:eu-repo/dai/nl/08747610X

    1988-01-01

    We present atomic calculations for the recently discovered magnetic x-ray dichroism (MXD) displayed by the 3d x-ray-absorption spectra of rare-earth compounds. The spectral shapes expected at T=0 K for linear polarization parallel and normal to the local magnetic field is given, together with the

  20. X-ray Fourier-transform holographic microscope

    International Nuclear Information System (INIS)

    Haddad, W.S.; Cullen, D.; Solem, J.C.; Boyer, K.; Rhodes, C.K.

    1988-01-01

    The properties of an x-ray Fourier-transform holographic instrument suitable for imaging hydrated biological samples are described. Recent advances in coherent x-ray source technology are making diffraction-limited holograms of microscopic structures, with corresponding high spatial resolution, a reality. A high priority application of snapshot x-ray holography is the study of microscopic biological structures in the hydrated living state. X-rays offer both high resolution and high contrast for important structures within living organisms, thereby rendering unnecessary the staining of specimens, essential for optical and electron microscopy. If the wavelength is properly chosen. Furthermore, the snapshot feature, arising from picosecond or subpicosecond exposure times, eliminates blurring occurring from either thermal heating or normal biological activity of the sample. Finally, with sufficiently high photon fluxes, such as those available from x-ray lasers, the x-ray snapshot can be accomplished with a single pulse, thereby yielding complete three-dimensional information on a sample having normal biological integrity at the moment of exposure. 10 refs., 6 figs

  1. High Resolution Gamma Ray Spectroscopy at MHz Counting Rates With LaBr3 Scintillators for Fusion Plasma Applications

    Science.gov (United States)

    Nocente, M.; Tardocchi, M.; Olariu, A.; Olariu, S.; Pereira, R. C.; Chugunov, I. N.; Fernandes, A.; Gin, D. B.; Grosso, G.; Kiptily, V. G.; Neto, A.; Shevelev, A. E.; Silva, M.; Sousa, J.; Gorini, G.

    2013-04-01

    High resolution γ-ray spectroscopy measurements at MHz counting rates were carried out at nuclear accelerators, combining a LaBr 3(Ce) detector with dedicated hardware and software solutions based on digitization and off-line analysis. Spectra were measured at counting rates up to 4 MHz, with little or no degradation of the energy resolution, adopting a pile up rejection algorithm. The reported results represent a step forward towards the final goal of high resolution γ-ray spectroscopy measurements on a burning plasma device.

  2. Extracting ion emission lines from femtosecond-laser plasma x-ray spectra heavily contaminated by spikes

    International Nuclear Information System (INIS)

    Gasilov, S. V.; Faenov, A. Ya.; Pikuz, T. A.; Villoresi, P.; Poletto, L.; Stagira, S.; Calegari, F.; Vozzi, C.; Nisoli, M.

    2007-01-01

    Nowadays charged-coupled device (CCD) detectors are widely used for the registration of multicharged ions x-ray spectra. These spectra are generated in a plasma during interaction of ultrashort, ultraintense laser pulses with solid targets. Strong parasitic radiation from the plasma affects CCD detectors and contaminates resulting spectra, so that spectral features can be completely covered by noise even during measurements with a very short accumulation time. In this work we propose a ''mean to median'' (M2M) algorithm for noise suppression in femtosecond laser plasma x-ray spectra. Series of spectra is necessary for the identification of corrupted data points by the developed method. The algorithm was tested with model spectra which reflect main features of experimental data. In practice we used it for extracting information about spectral lines of Ne-like Fe ions and He-like Al ions which allowed us to calculate plasma parameters. It is demonstrated that M2M method is able to clean spectra with more than 10% of corrupted pixels. Fluctuations in intensity of spectral lines induced by laser instability do not affect validity of the proposed method

  3. High resolution X-ray tomography for stationary multiphase flows

    International Nuclear Information System (INIS)

    Schmitz, D.; Reinecke, N.; Petritsch, G.; Mewes, D.

    1998-01-01

    The high resolution which can be obtained by computer assisted tomography is used to investigate the liquid distribution and void fraction in random and structured packing. With a spatial resolution of 0.4x0.4mm 2 it is possible even to detect thin liquid films on structured packings. The experimental set-up consists of a custom-built second generation tomograph. The imaged object consists of a column filled with either a random ceramic packing of spheres or a structured metal packing. The liquid and void fraction distribution in random and structured packings with a quiescent gaseous phase is visualized. The water/air system is used. The liquid distributor consists of a perforated plate. The experimental hold-up values averaged over the column cross-section are in good agreement with empirical equations. (author)

  4. A DEEP X-RAY VIEW OF THE BARE AGN ARK 120. I. REVEALING THE SOFT X-RAY LINE EMISSION

    Energy Technology Data Exchange (ETDEWEB)

    Reeves, J. N.; Braito, V. [Center for Space Science and Technology, University of Maryland Baltimore County, 1000 Hilltop Circle, Baltimore, MD 21250 (United States); Porquet, D. [Observatoire Astronomique de Strasbourg, Université de Strasbourg, CNRS, UMR 7550, 11 rue de l’Université, F-67000 Strasbourg (France); Nardini, E. [Astrophysics Group, School of Physical and Geographical Sciences, Keele University, Keele, Staffordshire, ST5 5BG (United Kingdom); Lobban, A. [Dept of Physics and Astronomy, University of Leicester, University Road, Leicester LE1 7RH (United Kingdom); Turner, T. J., E-mail: jreeves@umbc.edu, E-mail: j.n.reeves@keele.ac.uk [Department of Physics, University of Maryland Baltimore County, 1000 Hilltop Circle, Baltimore, MD 21250 (United States)

    2016-09-10

    The Seyfert 1 galaxy Ark 120 is a prototype example of the so-called class of bare nucleus active galactic nuclei (AGNs), whereby there is no known evidence for the presence of ionized gas along the direct line of sight. Here deep (>400 ks exposure), high-resolution X-ray spectroscopy of Ark 120 is presented from XMM-Newton observations that were carried out in 2014 March, together with simultaneous Chandra /High Energy Transmission Grating exposures. The high-resolution spectra confirmed the lack of intrinsic absorbing gas associated with Ark 120, with the only X-ray absorption present originating from the interstellar medium (ISM) of our own Galaxy, with a possible slight enhancement of the oxygen abundance required with respect to the expected ISM values in the solar neighborhood. However, the presence of several soft X-ray emission lines are revealed for the first time in the XMM-Newton RGS spectrum, associated with the AGN and arising from the He- and H-like ions of N, O, Ne, and Mg. The He-like line profiles of N, O, and Ne appear velocity broadened, with typical FWHMs of ∼5000 km s{sup −1}, whereas the H-like profiles are unresolved. From the clean measurement of the He-like triplets, we deduce that the broad lines arise from a gas of density n {sub e} ∼ 10{sup 11} cm{sup −3}, while the photoionization calculations infer that the emitting gas covers at least 10% of 4 π steradian. Thus the broad soft X-ray profiles appear coincident with an X-ray component of the optical–UV broad-line region on sub-parsec scales, whereas the narrow profiles originate on larger parsec scales, perhaps coincident with the AGN narrow-line region. The observations show that Ark 120 is not intrinsically bare and substantial X-ray-emitting gas exists out of our direct line of sight toward this AGN.

  5. Si(Li) X-ray detector

    International Nuclear Information System (INIS)

    Yuan Xianglin; Li Zhiyong; Hong Xiuse

    1990-08-01

    The fabrication technology of the 10∼80 mm 2 Si(Li) X-ray detectors are described and some problems concerning technology and measurement are discussed. The specifications of the detectors are shown as well. The Si(Li) X-ray detector is a kind of low energy X-ray detectors. Owing to very high energy resolution, fine linearity and high detection efficiency in the range of low energy X-rays, it is widely used in the fields of nuclear physics, medicine, geology and environmental protection, etc,. It is also a kernel component for the scanning electron microscope and X-ray fluorescence analysis systems

  6. The X-ray Astronomy Recovery Mission

    Science.gov (United States)

    Tashiro, M.; Kelley, R.

    2017-10-01

    On 25 March 2016, the Japanese 6th X-ray astronomical satellite ASTRO-H (Hitomi), launched on February 17, lost communication after a series of mishap in its attitude control system. In response to the mishap the X-ray astronomy community and JAXA analyzed the direct and root cause of the mishap and investigated possibility of a recovery mission with the international collaborator NASA and ESA. Thanks to great effort of scientists, agencies, and governments, the X-ray Astronomy Recovery Mission (XARM) are proposed. The recovery mission is planned to resume high resolution X-ray spectroscopy with imaging realized by Hitomi under the international collaboration in the shortest time possible, simply by focusing one of the main science goals of Hitomi Resolving astrophysical problems by precise high-resolution X-ray spectroscopy'. XARM will carry a 6 x 6 pixelized X-ray micro-calorimeter on the focal plane of an X-ray mirror assembly, and an aligned X-ray CCD camera covering the same energy band and wider field of view, but no hard X-ray or soft gamma-ray instruments are onboard. In this paper, we introduce the science objectives, mission concept, and schedule of XARM.

  7. An analysis of the MO X-ray spectra in U92+-Pb collisions

    International Nuclear Information System (INIS)

    Schulze, K.; Anton, J.; Sepp, W.-D.; Fricke, B.

    1999-01-01

    The investigation of quasimolecular X-rays from superheavy collision systems with bare or H-like projectiles seems to be a promising approach to get information about the behaviour of inner shell electrons with energy eigenvalues in the vicinity of the negative continuum. We present calculations of the MO X-ray spectra for the system U 92+ -Pb for varying impact energies. Furthermore we analyse the contributions due to electrons in higher lying states. The results are discussed with respect to the experimental determination of the transition energies in the superheavy quasimolecule. (orig.)

  8. Non-LTE model atmospheres for supersoft X-ray sources

    Science.gov (United States)

    Rauch, T.; Werner, K.

    2010-02-01

    In the last decade, X-ray observations of hot stellar objects became available with unprecedented resolution and S/N ratio. For an adequate interpretation, fully metal-line blanketed Non-LTE model-atmospheres are necessary. The Tübingen Non-LTE Model Atmosphere Package (TMAP) can calculate such model atmospheres at a high level of sophistication. Although TMAP is not especially designed for the calculation of spectral energy distributions (SEDs) at extreme photospheric parameters, it can be employed for the spectral analysis of burst spectra of novae like V4743 Sgr or line identifications in observations of neutron stars with low magnetic fields in low-mass X-ray binaries (LMXBs) like EXO 0748-676.

  9. X-ray speckle correlation interferometer

    International Nuclear Information System (INIS)

    Eisenhower, Rachel; Materlik, Gerhard

    2000-01-01

    Speckle Pattern Correlation Interferometry (SPCI) is a well-established technique in the visible-light regime for observing surface disturbances. Although not a direct imaging technique, SPCI gives full-field, high-resolution information about an object's motion. Since x-ray synchrotron radiation beamlines with high coherent flux have allowed the observation of x-ray speckle, x-ray SPCI could provide a means to measure strains and other quasi-static motions in disordered systems. This paper therefore examines the feasibility of an x-ray speckle correlation interferometer

  10. Development of full-field x-ray phase-tomographic microscope based on laboratory x-ray source

    Science.gov (United States)

    Takano, H.; Wu, Y.; Momose, A.

    2017-09-01

    An X-ray phase tomographic microscope that can quantitatively measure the refractive index of a sample in three dimensions with a high spatial resolution was developed by installing a Lau interferometer consisting of an absorption grating and a π/2 phase grating into the optics of an X-ray microscope. The optics comprises a Cu rotating anode X-ray source, capillary condenser optics, and a Fresnel zone plate for the objective. The microscope has two optical modes: a large-field-of-view mode (field of view: 65 μm x 65 μm) and a high-resolution mode (spatial resolution: 50 nm). Optimizing the parameters of the interferometer yields a self-image of the phase grating with 60% visibility. Through the normal fringe-scanning measurement, a twin phase image, which has an overlap of two phase image of opposite contrast with a shear distance much larger than system resolution, is generated. Although artifacts remain to some extent currently when a phase image is calculated from the twin phase image, this system can obtain high-spatial-resolution images resolving 50-nm structures. Phase tomography with this system has also been demonstrated using a phase object.

  11. Novel X-ray imaging diagnostics of high energy nanosecond pulse accelerators

    International Nuclear Information System (INIS)

    Smith, Graham W.; Gallegos, Roque Rosauro; Hohlfelder, Robert James; Beutler, David Eric; Dudley, John; Seymour, Calvin L.G.; Bell, John D.

    2004-01-01

    Pioneering x-ray imaging has been undertaken on a number of AWE's and Sandia National Laboratories radiation effects x-ray simulators. These simulators typically yield a single very short (<50ns) pulse of high-energy (MeV endpoint energy bremsstrahlung) x-ray radiation with doses in the kilorad (krad(Si)) region. X-ray source targets vary in size from 2 to 25cm diameter, dependent upon the particular simulator. Electronic imaging of the source x-ray emission under dynamic conditions yields valuable information upon how the simulator is performing. The resultant images are of interest to the simulator designer who may configure new x-ray source converter targets and diode designs. The images can provide quantitative information about machine performance during radiation effects testing of components under active conditions. The effects testing program is a valuable interface for validation of high performance computer codes and models for the radiation effects community. A novel high-energy x-ray imaging spectrometer is described whereby the spectral energy (0.1 to 2.5MeV) profile may be discerned from the digitally recorded and viewable images via a pinhole/scintillator/CCD imaging system and knowledge of the filtration parameters. Unique images, analysis and a preliminary evaluation of the capability of the spectrometer are presented. Further, a novel time resolved imaging system is described that captures a sequence of high spatial resolution temporal images, with zero interframe time, in the nanosecond timeframe, of our source x-rays.

  12. X-ray microscopy and spectromicroscopy - tools for environmental studies

    International Nuclear Information System (INIS)

    Thieme, J.

    2002-01-01

    Full text: X-ray microscopy achieves a much higher resolution than light microscopy. This is due to the much shorter wavelength of X-rays compared to visible light. The smallest structures that can be seen in an X-ray microscope at present are about 20 nm in size. X-ray microscopy is also capable of imaging specimens directly in aqueous media. By choosing the wavelength of the X-radiation appropriately, it is possible to perform spectromicroscopy studies. Comprising, it is a tool very well suited to study colloidal structures in the environment. X-ray microscopy can be performed with two types of instruments. An X-ray microscope quickly takes high-resolution images of objects to be studied, whereas a scanning X-ray microscope is an analytical instrument for spectromicroscopy. Here, an object can be imaged using energies above and below the absorption edge of an element. Dividing both images gives rise to a map of the distribution of this element in the sample. Using near-edge resonances it is possible to conduct NEXAFS studies. As the X-ray energy is raised to match the absorption edge resonances are found, that reflect the chemical bonding state of the element. Therefore, it is possible with X-ray microscopy to combine high spatial resolution with high spectral resolution for studies of colloidal structures. The Institute of X-ray physics builds up an X-ray microscopy beamline at the electron storage ring BESSY II with both, an X-ray microscope and a scanning X-ray microscope. The status of this beamline will be presented in this talk. Colloidal structures play an important role in the environment. Due to their surface activity they are involved in various processes. Substances can be bound and immobilized or transported, colloids can attach to microorganisms building up microhabitats, and organic substances as humics can flocculate due the interaction with metals. A great variety of colloidal structures from the environment have been studied using X-ray

  13. Measurement of high-dynamic range x-ray Thomson scattering spectra for the characterization of nano-plasmas at LCLS

    Energy Technology Data Exchange (ETDEWEB)

    MacDonald, M. J., E-mail: macdonm@umich.edu [University of Michigan, Ann Arbor, Michigan 48109 (United States); SLAC National Accelerator Laboratory, Menlo Park, California 94025 (United States); Gorkhover, T. [SLAC National Accelerator Laboratory, Menlo Park, California 94025 (United States); Technische Universität, 10623 Berlin (Germany); Bachmann, B.; Hau-Riege, S. P.; Pardini, T.; Döppner, T. [Lawrence Livermore National Laboratory, Livermore, California 94551 (United States); Bucher, M. [SLAC National Accelerator Laboratory, Menlo Park, California 94025 (United States); Argonne National Lab, Lemont, Illinois 60439 (United States); Carron, S. [California Lutheran University, Thousand Oaks, California 91360 (United States); Coffee, R. N.; Fletcher, L. B.; Gamboa, E. J.; Glenzer, S. H.; Göde, S.; Krzywinski, J.; O’Grady, C. P.; Osipov, T.; Swiggers, M. [SLAC National Accelerator Laboratory, Menlo Park, California 94025 (United States); Drake, R. P. [University of Michigan, Ann Arbor, Michigan 48109 (United States); Ferguson, K. R. [SLAC National Accelerator Laboratory, Menlo Park, California 94025 (United States); Stanford University, Stanford, California 94305 (United States); Kraus, D. [University of California, Berkeley, California 94720 (United States); and others

    2016-11-15

    Atomic clusters can serve as ideal model systems for exploring ultrafast (∼100 fs) laser-driven ionization dynamics of dense matter on the nanometer scale. Resonant absorption of optical laser pulses enables heating to temperatures on the order of 1 keV at near solid density conditions. To date, direct probing of transient states of such nano-plasmas was limited to coherent x-ray imaging. Here we present the first measurement of spectrally resolved incoherent x-ray scattering from clusters, enabling measurements of transient temperature, densities, and ionization. Single shot x-ray Thomson scattering signals were recorded at 120 Hz using a crystal spectrometer in combination with a single-photon counting and energy-dispersive pnCCD. A precise pump laser collimation scheme enabled recording near background-free scattering spectra from Ar clusters with an unprecedented dynamic range of more than 3 orders of magnitude. Such measurements are important for understanding collective effects in laser-matter interactions on femtosecond time scales, opening new routes for the development of schemes for their ultrafast control.

  14. A New High-sensitivity solar X-ray Spectrophotometer SphinX:early operations and databases

    Science.gov (United States)

    Gburek, Szymon; Sylwester, Janusz; Kowalinski, Miroslaw; Siarkowski, Marek; Bakala, Jaroslaw; Podgorski, Piotr; Trzebinski, Witold; Plocieniak, Stefan; Kordylewski, Zbigniew; Kuzin, Sergey; Farnik, Frantisek; Reale, Fabio

    The Solar Photometer in X-rays (SphinX) is an instrument operating aboard Russian CORONAS-Photon satellite. A short description of this unique instrument will be presented and its unique capabilities discussed. SphinX is presently the most sensitive solar X-ray spectrophotometer measuring solar spectra in the energy range above 1 keV. A large archive of SphinX mea-surements has already been collected. General access to these measurements is possible. The SphinX data repositories contain lightcurves, spectra, and photon arrival time measurements. The SphinX data cover nearly continuously the period since the satellite launch on January 30, 2009 up to the end-of November 2009. Present instrument status, data formats and data access methods will be shown. An overview of possible new science coming from SphinX data analysis will be discussed.

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

    Science.gov (United States)

    Nagel, S R; Hilsabeck, T J; Bell, P M; Bradley, D K; Ayers, M J; Piston, K; Felker, B; Kilkenny, J D; Chung, T; Sammuli, B; Hares, J D; Dymoke-Bradshaw, A K L

    2014-11-01

    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(17). We present characterization data as well as first results on electron-transport phenomena in buried-layer foil experiments.

  16. 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.

  17. Advances in indirect detector systems for ultra high-speed hard X-ray imaging with synchrotron light

    Science.gov (United States)

    Olbinado, M. P.; Grenzer, J.; Pradel, P.; De Resseguier, T.; Vagovic, P.; Zdora, M.-C.; Guzenko, V. A.; David, C.; Rack, A.

    2018-04-01

    We report on indirect X-ray detector systems for various full-field, ultra high-speed X-ray imaging methodologies, such as X-ray phase-contrast radiography, diffraction topography, grating interferometry and speckle-based imaging performed at the hard X-ray imaging beamline ID19 of the European Synchrotron—ESRF. Our work highlights the versatility of indirect X-ray detectors to multiple goals such as single synchrotron pulse isolation, multiple-frame recording up to millions frames per second, high efficiency, and high spatial resolution. Besides the technical advancements, potential applications are briefly introduced and discussed.

  18. Simulation study of spatial resolution in phase-contrast X-ray imaging with Takagi-Taupin equation

    International Nuclear Information System (INIS)

    Koyama, Ichiro; Momose, Atsushi

    2003-01-01

    To evaluate attainable spatial resolution of phase-contrast X-ray imaging using an LLL X-ray interferometer with a thin crystal wafer, a computer simulation study with Takagi-Taupin equation was performed. Modulation transfer function of the wafer for X-ray phase was evaluated. For a polyester film whose thickness is 0.1 mm, it was concluded that the spatial resolution can be improved up to 3 μm by thinning the wafer, under our experimental condition

  19. Development of X-ray CCD camera system with high readout rate using ASIC

    International Nuclear Information System (INIS)

    Nakajima, Hiroshi; Matsuura, Daisuke; Anabuki, Naohisa; Miyata, Emi; Tsunemi, Hiroshi; Doty, John P.; Ikeda, Hirokazu; Katayama, Haruyoshi

    2009-01-01

    We report on the development of an X-ray charge-coupled device (CCD) camera system with high readout rate using application-specific integrated circuit (ASIC) and Camera Link standard. The distinctive ΔΣ type analog-to-digital converter is introduced into the chip to achieve effective noise shaping and to obtain a high resolution with relatively simple circuits. The unit test proved moderately low equivalent input noise of 70μV with a high readout pixel rate of 625 kHz, while the entire chip consumes only 100 mW. The Camera Link standard was applied for the connectivity between the camera system and frame grabbers. In the initial test of the whole system, we adopted a P-channel CCD with a thick depletion layer developed for X-ray CCD camera onboard the next Japanese X-ray astronomical satellite. The characteristic X-rays from 109 Cd were successfully read out resulting in the energy resolution of 379(±7)eV (FWHM) at 22.1 keV, that is, ΔE/E=1.7% with a readout rate of 44 kHz.

  20. Identifying anthropogenic uranium compounds using soft X-ray near-edge absorption spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Ward, Jesse D.; Bowden, Mark; Tom Resch, C.; Eiden, Gregory C.; Pemmaraju, C. D.; Prendergast, David; Duffin, Andrew M.

    2017-01-01

    Uranium ores mined for industrial use are typically acid-leached to produce yellowcake and then converted into uranium halides for enrichment and purification. These anthropogenic chemical forms of uranium are distinct from their mineral counterparts. The purpose of this study is to use soft X-ray absorption spectroscopy to characterize several common anthropogenic uranium compounds important to the nuclear fuel cycle. Non-destructive chemical analyses of these compounds is important for process and environmental monitoring and X-ray absorption techniques have several advantages in this regard, including element-specificity, chemical sensitivity, and high spectral resolution. Oxygen K-edge spectra were collected for uranyl nitrate, uranyl fluoride, and uranyl chloride, and fluorine K-edge spectra were collected for uranyl fluoride and uranium tetrafluoride. Interpretation of the data is aided by comparisons to calculated spectra. These compounds have unique spectral signatures that can be used to identify unknown samples.