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Sample records for heat load x-ray

  1. Workshop on high heat load x-ray optics

    Energy Technology Data Exchange (ETDEWEB)

    1990-01-01

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

  2. Performance of synchrotron X-ray monochromators under heat load Part 1 finite element modeling

    CERN Document Server

    Zhang, L; Migliore, J S; Mocella, V; Ferrero, C; Freund, A K

    2001-01-01

    In this paper we present the details of the finite element modeling (FEM) procedure used to calculate the thermal deformation generated by the X-ray power absorbed in silicon crystals. Different parameters were varied systematically such as the beam footprint on the crystal, the reflection order and the white beam slit settings. Moreover, the influence of various cooling parameters such as the cooling coefficient and the temperature of the coolant were studied. The finite element meshing was carefully optimized to generate a deformation output that could be easily read by a diffraction simulation code. Comparison with the experiments shows that the peak-to-valley slope error calculated by the FEM is an excellent approximation of the rocking curve width for a liquid nitrogen cooled silicon (3 3 3) crystal, and a quite good approximation for significantly deformed silicon (1 1 1) crystals.

  3. Large-surface-area diamond (111) crystal plates for applications in high-heat-load wavefront-preserving x-ray crystal optics

    CERN Document Server

    Stoupin, S; Butler, J E; Kolyadin, A V; Katrusha, A

    2016-01-01

    We report fabrication and results of high-resolution X-ray topography characterization of diamond single crystal plates with a large surface area (10$\\times$10 mm$^2$) and (111) crystal surface orientation for applications in high-heat-load X-ray crystal optics. The plates were fabricated by laser cutting of the (111) facets of diamond crystals grown using high-pressure high-temperature method. The intrinsic crystal quality of a selected 3$\\times$7~mm$^2$ crystal region of one of the studied samples was found to be suitable for applications in wavefront-preserving high-heat-load crystal optics. The wavefront characterization was performed using sequential X-ray diffraction topography in the pseudo plane wave configuration and data analysis using rocking curve topography. The variation of the rocking curve width and peak position measured with a spatial resolution of 13$\\times$13 $\\mu m^2$ over the selected region were found to be less than one microradian.

  4. Large-surface-area diamond (111) crystal plates for applications in high-heat-load wavefront-preserving X-ray crystal optics.

    Science.gov (United States)

    Stoupin, Stanislav; Antipov, Sergey; Butler, James E; Kolyadin, Alexander V; Katrusha, Andrey

    2016-09-01

    Fabrication and results of high-resolution X-ray topography characterization of diamond single-crystal plates with large surface area (10 mm × 10 mm) and (111) crystal surface orientation for applications in high-heat-load X-ray crystal optics are reported. The plates were fabricated by laser-cutting of the (111) facets of diamond crystals grown using high-pressure high-temperature methods. The intrinsic crystal quality of a selected 3 mm × 7 mm crystal region of one of the studied samples was found to be suitable for applications in wavefront-preserving high-heat-load crystal optics. Wavefront characterization was performed using sequential X-ray diffraction topography in the pseudo plane wave configuration and data analysis using rocking-curve topography. The variations of the rocking-curve width and peak position measured with a spatial resolution of 13 µm × 13 µm over the selected region were found to be less than 1 µrad.

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

    CERN Document Server

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

    2015-01-01

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

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

    Science.gov (United States)

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

    2016-04-01

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

  7. Turbulent heating in galaxy clusters brightest in X-rays.

    Science.gov (United States)

    Zhuravleva, I; Churazov, E; Schekochihin, A A; Allen, S W; Arévalo, P; Fabian, A C; Forman, W R; Sanders, J S; Simionescu, A; Sunyaev, R; Vikhlinin, A; Werner, N

    2014-11-06

    The hot (10(7) to 10(8) kelvin), X-ray-emitting intracluster medium (ICM) is the dominant baryonic constituent of clusters of galaxies. In the cores of many clusters, radiative energy losses from the ICM occur on timescales much shorter than the age of the system. Unchecked, this cooling would lead to massive accumulations of cold gas and vigorous star formation, in contradiction to observations. Various sources of energy capable of compensating for these cooling losses have been proposed, the most promising being heating by the supermassive black holes in the central galaxies, through inflation of bubbles of relativistic plasma. Regardless of the original source of energy, the question of how this energy is transferred to the ICM remains open. Here we present a plausible solution to this question based on deep X-ray data and a new data analysis method that enable us to evaluate directly the ICM heating rate from the dissipation of turbulence. We find that turbulent heating is sufficient to offset radiative cooling and indeed appears to balance it locally at each radius-it may therefore be the key element in resolving the gas cooling problem in cluster cores and, more universally, in the atmospheres of X-ray-emitting, gas-rich systems on scales from galaxy clusters to groups and elliptical galaxies.

  8. X-ray stress analysis during cyclic loading

    Energy Technology Data Exchange (ETDEWEB)

    Ohya, Shin-ichi [Musashi Inst. of Tech., Tokyo (Japan)

    1997-06-01

    For an aim to make possible to conduct speed-up and time-serial measurement of x-ray stress measurement in the fatigue test, a diffraction intensity curve at each loading stress stage in a repeating stress period was measured in time-serial sharing and devised ``a time-sharing continuous stress measuring method by a single incident method`` to measure the stress continuously. Then, by using this method an actual stress change measurement was conducted in a four points supporting bending test, to investigate on precision of the stress measurement and effectiveness of this method. As a result, the results shown as follows were elucidated. An actual stress change in a fatigue test could be observed directly. And, it was confirmed that an actual stress state in each loading stress stage in one loading stress period is independent on repeating speed under about 8 Hz and is an algebraic sum of residual and loading stresses. Furthermore, it was found that by this method a dynamic fatigue cleavage phenomena could be observed. (G.K.)

  9. Ionization and heating by X-rays and cosmic rays*

    Directory of Open Access Journals (Sweden)

    Güdel Manuel

    2015-01-01

    Full Text Available High-energy radiation from the central T Tauri and protostars plays an important role in shaping protoplanetary disks and influences their evolution. Such radiation, in particular X-rays and extreme-ultraviolet (EUV radiation, is predominantly generated in unstable stellar magnetic fields (e.g., the stellar corona, but also in accretion hot spots. Even jets may produce X-ray emission. Cosmic rays, i.e., high-energy particles either from the interstellar space or from the star itself, are of crucial importance. Both highenergy photons and particles ionize disk gas and lead to heating. Ionization and heating subsequently drive chemical networks, and the products of these processes are accessible through observations of molecular line emission. Furthermore, ionization supports the magnetorotational instability and therefore drives disk accretion, while heating of the disk surface layers induces photoevaporative flows. Both processes are crucial for the dispersal of protoplanetary disks and therefore critical for the time scales of planet formation. This chapter introduces the basic physics of ionization and heating starting from a quantum mechanical viewpoint, then discusses relevant processes in astrophysical gases and their applications to protoplanetary disks, and finally summarizes some properties of the most important high-energy sources for protoplanetary disks.

  10. Turbulent Heating in Galaxy Clusters Brightest in X-rays

    CERN Document Server

    Zhuravleva, I; Schekochihin, A A; Allen, S W; Arevalo, P; Fabian, A C; Forman, W R; Sanders, J S; Simionescu, A; Sunyaev, R; Vikhlinin, A; Werner, N

    2014-01-01

    The hot, X-ray-emitting intracluster medium (ICM) is the dominant baryonic constituent of clusters of galaxies. In the cores of many clusters, radiative energy losses from the ICM occur on timescales significantly shorter than the age of the system. Unchecked, this cooling would lead to massive accumulations of cold gas and vigorous star formation, in contradiction to observations. Various sources of energy capable of compensating these cooling losses have been proposed, the most promising being heating by the supermassive black holes in the central galaxies through inflation of bubbles of relativistic plasma. Regardless of the original source of energy, the question of how this energy is transferred to the ICM has remained open. Here we present a plausible solution to this question based on deep Chandra X-ray observatory data and a new data-analysis method that enables us to evaluate directly the ICM heating rate due to the dissipation of turbulence. We find that turbulent heating is sufficient to offset rad...

  11. Fracture of metals samples under conditions of fast heating by intensive X-ray radiation

    Directory of Open Access Journals (Sweden)

    Golubev V.K.

    2012-08-01

    Full Text Available Results on studying the fracture of metals samples in the form of thin disks under fast heating by the X-ray pulse with the complete spectrum are presented in the paper. The samples of such metals as iron, copper, AMg6 aluminum, VT14 titanium, molybdenum, tungsten, cadmium, lead and zinc were tested. The samples were fixed in the special cartridges equipped with the gauges of a mechanical recoil momentum. The cartridges with samples were placed at such distances from the X-ray irradiator where the energy fluxes were 1.38, 0.90 and 0.29kJ/cm2. The irradiating X-ray pulse was about 2 ns in duration. After testing, the depth of material ablation from a sample front surface and the degree and character of its spall damage were determined. The method of metallographic analysis was used for these purposes. Numerical calculations of loading conditions were made with the use of an equation of state taking into account the process of evaporation. The calculated value of maximum negative pressure in the sample at the coordinate corresponding to the formation of spallation zones or spall cracks was conventionally accepted as the material resistance to spall fracture. The comparison of obtained results with the data on the fracture of examined materials in the conditions of fast heating by the X-ray pulse with the hard spectrum and a high-current electron beam was conducted.

  12. Fracture response of several metals to fast heating of samples by intensive X-ray radiation

    Science.gov (United States)

    Golubev, Vladimir

    2015-06-01

    Results on studying the fracture response of metals samples in the form of thin disks to fast heating by the intensive pulse of X-ray radiation of a complete spectrum are presented in the paper. The samples of such metals as iron, copper, AMg6 aluminum, VT14 titanium, molybdenum, tungsten, cadmium, lead and zinc were tested. The samples were fixed in the special cartridges that were placed at such distances from the X-ray irradiator where the energy fluxes were 1.38, 0.90 and 0.29 kJ/cm2. The irradiating X-ray pulse was about 2 ns in duration. After testing, the depth of material ablation from a sample front surface and the degree and character of its spall damage were determined. The method of metallographic analysis was used for these purposes. The spectrum data were used for the calculations of samples heating. Numerical calculations of thermomechanical and shock wave loading conditions were made with the use of the equation of state taking into account the process of evaporation. The calculated value of maximum negative pressure in the sample at the coordinate corresponding to the depth of ablation and formation of spallation zones or spall cracks was conventionally accepted as the material resistance to spall fracture in such conditions. The comparison of obtained results with the data on the fracture of examined materials in the conditions of fast heating by the X-ray pulse with a hard spectrum and by the high-current electron beam of an electron pulse generator was conducted.

  13. On the X-ray heated skin of Accretion Disks

    CERN Document Server

    Nayakshin, S

    1999-01-01

    We present a simple analytical formula for the Thomson depth of the X-rayheated skin of accretion disks valid at any radius and for a broad range ofspectral indices of the incident X-rays, accretion rates and black hole masses.We expect that this formula may find useful applications in studies of geometryof the inner part of accretion flows around compact objects, and in severalother astrophysically important problems, such as the recently observed X-ray``Baldwin'' effect (i.e., monotonic decrease of Fe line's equivalent width withthe X-ray luminosity of AGN), the problem of missing Lyman edge in AGN, andline and continuum variability studies in accretion disks around compactobjects. We compute the reflected X-ray spectra for several representativecases and show that for hard X-ray spectra and large ionizing fluxes the skinrepresents a perfect mirror that does not produce any Fe lines or absorptionfeatures. At the same time, for soft X-ray spectra or small ionizing fluxes,the skin produces very strong ionized...

  14. Ultrafast Time Resolved X-ray Diffraction Studies of Laser Heated Metals and Semiconductors

    Science.gov (United States)

    Chen, Peilin; Tomov, I. V.; Rentzepis, P. M.

    1998-03-01

    Time resolved hard x-ray diffraction has been employed to study the dynamics of lattice structure deformation. When laser pulse energy is deposited in a material it generates a non uniform transient temperature distribution, which alters the lattice structure of the crystal. The deformed crystal lattice will change the angle of diffraction for a monochromatic x-ray beam. We report picosecond and nanosecond time resolved x-ray diffraction measurements of the lattice temperature distribution, transient structure and stress, in Pt (111) and GaAs (111) crystals, caused by pulsed UV laser irradiation. An ArF excimer laser operated at 300 Hz was used, both, to drive an x-ray diode with copper anode and heat the crystal. Bragg diffracted x-ray radiation was recorded by a direct imaging x-ray CCD. Changes in the diffraction patterns induced by a few millijouls pulse energy were observed at different time delays between the laser heating pulse and the x-ray probing pulse. A kinematical model for time resolved x-ray diffraction was used to analyze the experimental data. Good agreement between the measured and calculated scattered x-ray intensities profiles was achieved, indicating that detailed time resolved x-ray diffraction measurements can be made with nanosecond and picosecond resolution for small temperature changes. Our system can detect changes in the lattice spacing of about 10-3 A.

  15. Numerical studies of gravitational accretion from x-ray heated stellar winds. Doctoral thesis

    Energy Technology Data Exchange (ETDEWEB)

    Lupo, J.A.

    1981-12-01

    We present three numerical models of accretion from radiation driven stellar winds onto compact objects in massive X-ray binary systems. The wind is given a velocity profile consistent with a radiatively driven wind, and a 'negative mass' gravitational potential is derived from this profile to represent the wind driving force in the hydrodynamic equations. An X-ray heating model is used which determines the X-ray heating time from the Compton heating time and the known steady state energies for optically thin gas illuminated by X-rays. This allows X-ray heating to be included in the hydrodynamic equations. The X-ray luminosity is held proportional to the accretion rate, assuming that the gravitational potential energy released is equivalent to 10% of the infalling rest-mass energy. A two-dimensional Eulerian computer code is used to solve the equations of motion. Model estimates of the ionization structure, accretion rates and flow characteristics, and the effects of thermal instabilities are discussed. The impact of the X-ray radiation on the wind driving force is demonstrated. Results indicate a possible mechanism for slow X-ray flares, such as observed in 4U1700-37.

  16. Numerical studies of gravitational accretion from x-ray heated stellar winds

    Energy Technology Data Exchange (ETDEWEB)

    Lupo, J.A.

    1981-01-01

    Three numerical models of accretion from radiation driven stellar winds onto compact objects in massive x-ray binary systems are presented. The wind is given a velocity profile consistent with a radiatively driven wind, and a ''negative mass'' gravitational potential is derived from this profile to represent the wind driving force in the hydrodynamic equations. An x-ray heating model is used which determines the x-ray heating time from the Compton heating time and the known steady state energies for optically thin gas illuminated by x-rays. This allows x-ray heating to be included in the hydrodynamic equations. The x-ray luminosity is held proportional to the accretion rate, assuming that the gravitational potential energy released is equivalent to 10% of the infalling rest-mass energy. A two-dimensional Eulerian computer code is used to solve the equations of motion. Model estimates of the ionization structure, accretion rates and flow characteristics, and the effects of thermal instabilities are discussed. The impact of the x-ray radiation on the wind driving force is demonstrated. Results indicate a possible mechanism for slow x-ray flares, such as observed in 4U1700-37.

  17. Note: A novel method for in situ loading of gases via x-ray induced chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Pravica, Michael; Bai, Ligang; Park, Changyong; Liu, Yu; Galley, Martin; Robinson, John; Bhattacharya, Neelanjan (UNLV); (CIW)

    2011-12-14

    We have developed and demonstrated a novel method to load oxygen in a sealed diamond anvil cell via the x-ray induced decomposition of potassium chlorate. By irradiating a pressurized sample of an oxidizer (KClO{sub 3}) with either monochromatic or white beam x-rays from the Advanced Photon Source at ambient temperature and variable pressure, we succeeded in creating a localized region of molecular oxygen surrounded by unreacted sample which was confirmed via Raman spectroscopy. We anticipate that this technique will be useful in loading even more challenging, difficult-to-load gases such as hydrogen and also to load multiple gases.

  18. X-ray Sources Generated from Gas-Filled Laser-Heated Targets

    Energy Technology Data Exchange (ETDEWEB)

    Back, C A; Grun, J; Decker, C D; Davis, J; Laming, J M; Feldman, U; Suter, L J; Landen, O L; Miller, M; Serduke, F; Wuest, C

    2000-06-06

    The X-ray sources in the 4-7 keV energy regime can be produced by laser-irradiating high-Z gas-filled targets with high-powered lasers. A series of experiments have been performed using underdense targets that are supersonically heated with {approx} 35 W of 0.35 {micro}m laser light. These targets were cylindrical Be enclosures that were filled with 1-2 atms of Xe gas. L-shell x-ray emission is emitted from the plasma and detected by Bragg crystal spectrometers and x-ray diodes. Absolute flux measurements show conversion efficiencies of {approx} 10% in the multi-kilovolt x-ray emission. These sources can be used as bright x-ray backlighters or for material testing.

  19. The heating of X-ray gas by radio gas in cluster PKS0745-191

    Science.gov (United States)

    Xiang, F.; Chen, Y.; Wu, M.; Lu, F. J.; Song, L. M.; Jia, S. M..

    2004-05-01

    A calculation about the energy evolution of the relativistic particles in galaxy clusters is presented. The heating of X-ray gas by radio gas in cluster PKS 0745-191 is derived through a combined analysis of Chandra data and VLA radio observations. It was found that the heating of X-ray gas by radio gas is not enough to supply the energy lose by the X-ray emission when the low energy cut-off in the power-law spectrum of the relativistic electrons is set to 0.001erg. Therefore further computing is made to study the heating of X-ray gas by radio gas with different low energy cut-off is computed and the low energy cut-off values.

  20. Pulsar Polar Cap Heating and Surface Thermal X-Ray Emission I. Curvature Radiation Pair Fronts

    CERN Document Server

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

    2001-01-01

    We investigate the effect of pulsar polar cap (PC) heating produced by positrons returning from the upper pair formation front. Our calculations are based on a self-consistent treatment of the pair dynamics and the effect of electric field screening by the returning positrons. We calculate the resultant X-ray luminosities, and discuss the dependence of the PC heating efficiencies on pulsar parameters, such as characteristic spin-down age, spin period, and surface magnetic field strength. In this study we concentrate on the regime where the pairs are produced in a magnetic field by curvature photons emitted by accelerating electrons. Our theoretical results are not in conflict with the available observational X-ray data and suggest that the effect of PC heating should significantly contribute to the thermal X-ray fluxes from middle-aged and old pulsars. The implications for current and future X-ray observations of pulsars are briefly outlined.

  1. X-ray analysis of electron Bernstein wave heating in MST

    Science.gov (United States)

    Seltzman, A. H.; Anderson, J. K.; DuBois, A. M.; Almagri, A.; Forest, C. B.

    2016-11-01

    A pulse height analyzing x-ray tomography system has been developed to detect x-rays from electron Bernstein wave heated electrons in the Madison symmetric torus reversed field pinch (RFP). Cadmium zinc telluride detectors are arranged in a parallel beam array with two orthogonal multi-chord detectors that may be used for tomography. In addition a repositionable 16 channel fan beam camera with a 55° field of view is used to augment data collected with the Hard X-ray array. The chord integrated signals identify target emission from RF heated electrons striking a limiter located 12° toroidally away from the RF injection port. This provides information on heated electron spectrum, transport, and diffusion. RF induced x-ray emission from absorption on harmonic electron cyclotron resonances in low current (<250 kA) RFP discharges has been observed.

  2. X-ray analysis of electron Bernstein wave heating in MST

    Energy Technology Data Exchange (ETDEWEB)

    Seltzman, A. H., E-mail: seltzman@wisc.edu; Anderson, J. K.; DuBois, A. M.; Almagri, A.; Forest, C. B. [Department of Physics, University of Wisconsin, Madison, Wisconsin 53706 (United States)

    2016-11-15

    A pulse height analyzing x-ray tomography system has been developed to detect x-rays from electron Bernstein wave heated electrons in the Madison symmetric torus reversed field pinch (RFP). Cadmium zinc telluride detectors are arranged in a parallel beam array with two orthogonal multi-chord detectors that may be used for tomography. In addition a repositionable 16 channel fan beam camera with a 55° field of view is used to augment data collected with the Hard X-ray array. The chord integrated signals identify target emission from RF heated electrons striking a limiter located 12° toroidally away from the RF injection port. This provides information on heated electron spectrum, transport, and diffusion. RF induced x-ray emission from absorption on harmonic electron cyclotron resonances in low current (<250 kA) RFP discharges has been observed.

  3. Detection of Heating Processes in Coronal Loops by Soft X-ray Spectroscopy

    Science.gov (United States)

    Kawate, Tomoko; Narukage, Noriyuki; Ishikawa, Shin-nosuke; Imada, Shinsuke

    2017-08-01

    Imaging and Spectroscopic observations in the soft X-ray band will open a new window of the heating/acceleration/transport processes in the solar corona. The soft X-ray spectrum between 0.5 and 10 keV consists of the electron thermal free-free continuum and hot coronal lines such as O VIII, Fe XVII, Mg XI, Si XVII. Intensity of free-free continuum emission is not affected by the population of ions, whereas line intensities especially from highly ionized species have a sensitivity of the timescale of ionization/recombination processes. Thus, spectroscopic observations of both continuum and line intensities have a capability of diagnostics of heating/cooling timescales. We perform a 1D hydrodynamic simulation coupled with the time-dependent ionization, and calculate continuum and line intensities under different heat input conditions in a coronal loop. We also examine the differential emission measure of the coronal loop from the time-integrated soft x-ray spectra. As a result, line intensity shows a departure from the ionization equilibrium and shows different responses depending on the frequency of the heat input. Solar soft X-ray spectroscopic imager will be mounted in the sounding rocket experiment of the Focusing Optics X-ray Solar Imager (FOXSI). This observation will deepen our understanding of heating processes to solve the “coronal heating problem”.

  4. In situ laser heating and radial synchrotron X-ray diffraction ina diamond anvil cell

    Energy Technology Data Exchange (ETDEWEB)

    Kunz, Martin; Caldwell, Wendel A.; Miyagi, Lowell; Wenk,Hans-Rudolf

    2007-06-29

    We report a first combination of diamond anvil cell radialx-ray diffraction with in situ laser heating. The laser-heating setup ofALS beamline 12.2.2 was modified to allow one-sided heating of a samplein a diamond anvil cell with an 80 W yttrium lithium fluoride laser whileprobing the sample with radial x-ray diffraction. The diamond anvil cellis placed with its compressional axis vertical, and perpendicular to thebeam. The laser beam is focused onto the sample from the top while thesample is probed with hard x-rays through an x-ray transparentboron-epoxy gasket. The temperature response of preferred orientation of(Fe,Mg)O is probed as a test experiment. Recrystallization was observedabove 1500 K, accompanied by a decrease in stress.

  5. In situ laser heating and radial synchrotron X-ray diffraction ina diamond anvil cell

    Energy Technology Data Exchange (ETDEWEB)

    Kunz, Martin; Caldwell, Wendel A.; Miyagi, Lowell; Wenk,Hans-Rudolf

    2007-06-29

    We report a first combination of diamond anvil cell radialx-ray diffraction with in situ laser heating. The laser-heating setup ofALS beamline 12.2.2 was modified to allow one-sided heating of a samplein a diamond anvil cell with an 80 W yttrium lithium fluoride laser whileprobing the sample with radial x-ray diffraction. The diamond anvil cellis placed with its compressional axis vertical, and perpendicular to thebeam. The laser beam is focused onto the sample from the top while thesample is probed with hard x-rays through an x-ray transparentboron-epoxy gasket. The temperature response of preferred orientation of(Fe,Mg)O is probed as a test experiment. Recrystallization was observedabove 1500 K, accompanied by a decrease in stress.

  6. Heating of low-density CHO-foam layers by means of soft X-rays

    Energy Technology Data Exchange (ETDEWEB)

    Rosmej, O.N., E-mail: o.rosmej@gsi.de [GSI Helmholtzzentrum fuer Schwerionenforschung, Planckstrasse 1, 164291 Darmstadt (Germany); Bagnoud, V.; Eisenbarth, U. [GSI Helmholtzzentrum fuer Schwerionenforschung, Planckstrasse 1, 164291 Darmstadt (Germany); Vatulin, V.; Zhidkov, N.; Suslov, N.; Kunin, A.; Pinegin, A. [All Russian Scientific Research Institute of Experimental Physics, RFNC-VNIIEF, Mira St. 37, Sarov (Russian Federation); Schaefer, D.; Nisius, Th.; Wilhein, Th. [RheinAhrCampus Remagen, Institute for X-optics, Suedallee 2, 53424 Remagen (Germany); Rienecker, T.; Wiechula, J.; Jacoby, J. [Goethe University, Frankfurt am Main (Germany); Zhao, Y. [Institute of Modern Physics, CAS, Nanchang Road 509, 730000 Lanzhou (China); Vergunova, G.; Borisenko, N. [Lebedev Physical Institute, Leninskii Prospekt, 65 Moscow (Russian Federation); Orlov, N. [Joint Institute for High Temperatures RAS, Institute for High Energy Density, Izhorskaya. 13, building 2, 125412 Moscow (Russian Federation)

    2011-10-11

    Interaction of soft X-ray thermal radiation with polymer foam layers has been studied experimentally. Indirectly heated CHO-foams were used to create a plasma target for applications in combined heavy ion beam-laser experiments that are aimed at investigation of the heavy ion energy loss in ionized matter. In this work, we report experimental results on heating of low Z foams by means of the Planckian radiation generated in gold hohlraums. The experimental goal was to study the hohlraum radiation field, duration of the soft X-ray pulse, the conversion efficiency of the laser energy into soft X-rays, measurements of the absorption properties of foam layers and parameters of the foam targets heated by the Plankian radiation.

  7. Characterization of the ultrafast x-ray heating of iron foils

    Science.gov (United States)

    Gamboa, Eliseo; Loisel, Guillaume; Heimann, Philip; Bailey, James; Falcone, Roger; Galtier, Eric; Glenzer, Siegfried; MacKinnon, Andy; Mancini, Roberto; Saunders, Alison; Hansen, Stephanie

    2016-10-01

    We present experimental data showing the thermodynamic response of metal foils to intense x-ray irradiation. Thin (300 nm) iron foils were irradiated with up to 3 mJ of x-rays in a 9 keV, 40 fs free electron laser pulse generated by the Linac Coherent Light Source, Stanford University. The x-rays heat the foil uniformly, depositing several keV/atom to create a hot-dense state. We observed the non-collective x-ray scattering from the laser pulse, obtaining wavelength-resolved spectra that are sensitive to the temperature and charge distribution in the sample. The values inferred from the x-ray scattering are compared to predictions from atomic kinetics simulations as well as time-integrated measurements of the temperature from the soft x-ray bremsstrahlung emission. The work presented here was carried out at the Linac Coherent Light Source (LCLS), a national user facility operated by Stanford University for the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-7.

  8. Non-invasive measurement of X-ray beam heating on a surrogate crystal sample.

    Science.gov (United States)

    Snell, Edward H; Bellamy, Henry D; Rosenbaum, Gerd; van der Woerd, Mark J

    2007-01-01

    Cryocooling is a technique routinely used to mitigate the effects of secondary radiation damage on macromolecules during X-ray data collection. Energy from the X-ray beam absorbed by the sample raises the temperature of the sample. How large is the temperature increase and does this reduce the effectiveness of cryocooling? Sample heating by the X-ray beam has been measured non-invasively for the first time by means of thermal imaging. Specifically, the temperature rise of 1 mm and 2 mm glass spheres (sample surrogates) exposed to an intense synchrotron X-ray beam and cooled in a laminar flow of nitrogen gas is experimentally measured. For the typical sample sizes, photon energies, fluxes, flux densities and exposure times used for macromolecular crystallographic data collection at third-generation synchrotron radiation sources and with the sample accurately centered in the cryostream, the heating by the X-ray beam is only a few degrees. This is not sufficient to raise the sample above the amorphous-ice/crystalline-ice transition temperature and, if the cryostream cools the sample to 100 K, not even enough to significantly enhance radiation damage from secondary effects.

  9. Method of time resolved refractive index measurements of x-ray laser heated solids

    Energy Technology Data Exchange (ETDEWEB)

    Williams, G. O.; Kuenzel, S.; Fajardo, M. [GoLP/Instituto de Plasmas e Fusao Nuclear-Laboratorio Associado, Instituto Superior Tecnico, 1049-001 Lisboa (Portugal); Chung, H.-K. [Atomic and Molecular Data Unit, Nuclear Data Section, IAEA, PO Box 100, A-1400 Vienna (Austria); Vinko, S. M. [Department of Physics, Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU (United Kingdom); Sardinha, A. B. [GoLP/Instituto de Plasmas e Fusao Nuclear-Laboratorio Associado, Instituto Superior Tecnico, 1049-001 Lisboa (Portugal); Laboratoire d' Optique Appliquee, Ecole Nationale Superieure de Technique Avancees, Ecole Polytechnique, CNRS UMR7639, Chemin de la Huniere, 91761 Palaiseau Cedex (France); Zeitoun, Ph. [Laboratoire d' Optique Appliquee, Ecole Nationale Superieure de Technique Avancees, Ecole Polytechnique, CNRS UMR7639, Chemin de la Huniere, 91761 Palaiseau Cedex (France)

    2013-04-15

    With the advent of new x-ray light-sources worldwide, the creation of dense, uniformly heated plasma states arising from intense x-ray irradiation of solids has been made possible. In the early stages of x-ray solid heating, before significant hydrodynamic motion occurs, the matter exists in a highly non-equilibrium state. A method based on wavefront sensing is proposed to probe some of the fundamental properties of these states. The deflection and absorption of a high harmonic probe beam propagated through the plasma can be measured with a wavefront sensor, and allow for the determination of the complex refractive index (RI) of the plasma, giving a 2D map of the optical properties as function of time in a pump-probe arrangement. A solid heating model has been used to estimate the expected temperatures of x-ray heated thin foils, and these temperatures are used in three separate models to estimate the changes in the refractive index. The calculations show the changes induced on an extreme ultra-violet (XUV) probe beam by a solid density thin foil plasma are significant, in terms of deflection angle and absorption, to be measured by already existing XUV Hartmann wavefront sensors. The method is applicable to a wide range of photon energies in the XUV (10 s to several 100 s of eV) and plasma parameters, and can add much needed experimental data to the fundamental properties of such dense plasma states.

  10. Simulating the Impact of X-ray Heating during the Cosmic Dawn

    CERN Document Server

    Ross, Hannah E; Iliev, Ilian T; Mellema, Garrelt

    2016-01-01

    Upcoming observations of the 21-cm signal from the Epoch of Reionization will soon provide us with the first direct detection of this era. This signal is influenced by many astrophysical effects, including long range X-ray heating of the intergalactic gas. During the preceding Cosmic Dawn era the impact of this heating on the 21-cm signal is particularly prominent, especially before spin temperature saturation. We present the largest-volume (244~$h^{-1}$Mpc=349\\,Mpc comoving) full numerical radiative transfer simulations to date of this epoch, including the effects of helium and multi-frequency heating, both with and without X-ray sources. We show that X-ray sources can contribute significantly to early heating of the neutral intergalactic medium and, hence, to the corresponding 21-cm signal. The inclusion of hard, energetic radiation yields an earlier, extended transition from absorption to emission compared to the stellar-only case. The presence of X-ray sources decreases the absolute value of the mean 21-c...

  11. Water maser emission from X-ray-heated circumnuclear gas in active galaxies

    Science.gov (United States)

    Neufeld, David A.; Maloney, Philip R.; Conger, Sarah

    1994-01-01

    We have modeled the physical and chemical conditions present within dense circumnuclear gas that is irradiated by X-rays from an active galactic nucleus. Over a wide range of X-ray fluxes and gas pressures, the effects of X-ray heating give rise to a molecular layer at temperatures of 400-1000 K within which the water abundance is large. The physical conditions within this molecular layer naturally give rise to collisionally pumped maser emission in the 6(sub 16) - 5(sub 23) 22 GHz transition of ortho-water, with predicted maser luminosities of 10(exp 2 +/- 0.5) solar luminosity per sq. pc of illuminated area. Given plausible assumptions about the geometry of the source and about the degree to which the maser emission is anisotropic, such surface luminosities are sufficient to explain the large apparent luminosities observed in water maser sources that are associated with active galactic nuclei.

  12. X-Ray Heating of the Ejecta of Supernova 1987A

    Science.gov (United States)

    Sonneborn, George; Larsson, Josefin; Fransson, Claes; Kirshner, Robert; Challis, Peter; McCray, Richard

    2012-01-01

    Analysis of Hubble Space Telescope Band R band images from 1994 to 2009 show that the optical luminosity of SN 1987A has transitioned from being powered by radioactive decay of Ti-44 to energy deposited by X-rays produced as the ejecta interacts with the surrounding material (Larsson et al. 2011, Nature, 474, 484). The B and R band flux from the densest, central parts of the ejecta followed the expected exponential decline until 2001 (about day 5000) when the flux in these bands started increasing, more than doubling by the end of 2009. This increase is the result of heat deposited by X-rays from the shock interaction of the fast-moving outer ejecta with the inner circumstellar ring. In time, the X-rays will penetrate farther into the ejecta, enabling us to analyze the structure and chemistry of the vanished star.

  13. Water maser emission from X-ray-heated circumnuclear gas in active galaxies

    Science.gov (United States)

    Neufeld, David A.; Maloney, Philip R.; Conger, Sarah

    1994-12-01

    We have modeled the physical and chemical conditions present within dense circumnuclear gas that is irradiated by X-rays from an active galactic nucleus. Over a wide range of X-ray fluxes and gas pressures, the effects of X-ray heating give rise to a molecular layer at temperatures of 400-1000 K within which the water abundance is large. The physical conditions within this molecular layer naturally give rise to collisionally pumped maser emission in the 616 - 523 22 GHz transition of ortho-water, with predicted maser luminosities of 102 +/- 0.5 solar luminosity per sq. pc of illuminated area. Given plausible assumptions about the geometry of the source and about the degree to which the maser emission is anisotropic, such surface luminosities are sufficient to explain the large apparent luminosities observed in water maser sources that are associated with active galactic nuclei.

  14. A streaked X-ray spectroscopy platform for rapidly heated, near-solid density plasmas

    Science.gov (United States)

    Stillman, C. R.; Nilson, P. M.; Ivancic, S. T.; Mileham, C.; Begishev, I. A.; Junquist, R. K.; Nelson, D. J.; Froula, D. H.

    2016-11-01

    A picosecond, time-resolved, x-ray spectroscopy platform was developed to study the thermal line emission from rapidly heated solid targets containing buried aluminum or iron layers. The targets were driven by high-contrast 1ω or 2ω laser pulses at focused intensities up to 1 × 1019 W/cm2. The experimental platform combines time-integrating and time-resolved x-ray spectrometers. Picosecond time resolution was achieved with a pair of ultrafast x-ray streak cameras coupled to high-throughput Hall spectrometers. Time-integrated spectra were collected on each shot to correct the streaked data for variations in x-ray photocathode spectral sensitivity. The time-integrated spectrometer uses three elliptical crystals to disperse x rays with energies between 800 and 2100 eV with moderate (E/ΔE ˜ 450) resolving power. The streaked spectrometers accept four interchangeable conical crystals with higher resolving power (E/ΔE ˜ 650) to measure the brightest thermal lines in the 1300 to 1700 eV spectral range.

  15. Time-resolved x-ray diffraction techniques for bulk polycrystalline materials under dynamic loading.

    Science.gov (United States)

    Lambert, P K; Hustedt, C J; Vecchio, K S; Huskins, E L; Casem, D T; Gruner, S M; Tate, M W; Philipp, H T; Woll, A R; Purohit, P; Weiss, J T; Kannan, V; Ramesh, K T; Kenesei, P; Okasinski, J S; Almer, J; Zhao, M; Ananiadis, A G; Hufnagel, T C

    2014-09-01

    We have developed two techniques for time-resolved x-ray diffraction from bulk polycrystalline materials during dynamic loading. In the first technique, we synchronize a fast detector with loading of samples at strain rates of ~10(3)-10(4) s(-1) in a compression Kolsky bar (split Hopkinson pressure bar) apparatus to obtain in situ diffraction patterns with exposures as short as 70 ns. This approach employs moderate x-ray energies (10-20 keV) and is well suited to weakly absorbing materials such as magnesium alloys. The second technique is useful for more strongly absorbing materials, and uses high-energy x-rays (86 keV) and a fast shutter synchronized with the Kolsky bar to produce short (~40 μs) pulses timed with the arrival of the strain pulse at the specimen, recording the diffraction pattern on a large-format amorphous silicon detector. For both techniques we present sample data demonstrating the ability of these techniques to characterize elastic strains and polycrystalline texture as a function of time during high-rate deformation.

  16. Time-resolved x-ray diffraction techniques for bulk polycrystalline materials under dynamic loading

    Energy Technology Data Exchange (ETDEWEB)

    Lambert, P. K.; Hustedt, C. J.; Zhao, M.; Ananiadis, A. G.; Hufnagel, T. C. [Department of Materials Science and Engineering, Johns Hopkins University, Baltimore, Maryland 21218 (United States); Vecchio, K. S. [Department of NanoEngineering, University of California San Diego, La Jolla, California 92093 (United States); Huskins, E. L. [Oak Ridge Institute for Science and Education, Oak Ridge, Tennessee 37830 (United States); US Army Research Laboratory, Aberdeen Proving Ground, Aberdeen, Maryland 21005 (United States); Casem, D. T. [US Army Research Laboratory, Aberdeen Proving Ground, Aberdeen, Maryland 21005 (United States); Gruner, S. M. [Department of Physics, Cornell University, Ithaca, New York 14853 (United States); Cornell High Energy Synchrotron Source (CHESS), Cornell University, Ithaca, New York 14853 (United States); Kavli Institute at Cornell for Nanoscale Science, Cornell University, Ithaca, New York 14853 (United States); Tate, M. W.; Philipp, H. T.; Purohit, P.; Weiss, J. T. [Department of Physics, Cornell University, Ithaca, New York 14853 (United States); Woll, A. R. [Cornell High Energy Synchrotron Source (CHESS), Cornell University, Ithaca, New York 14853 (United States); Kannan, V.; Ramesh, K. T. [Department of Mechanical Engineering, Johns Hopkins University, Baltimore, Maryland 21218 (United States); Kenesei, P.; Okasinski, J. S.; Almer, J. [X-ray Science Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States)

    2014-09-15

    We have developed two techniques for time-resolved x-ray diffraction from bulk polycrystalline materials during dynamic loading. In the first technique, we synchronize a fast detector with loading of samples at strain rates of ∼10{sup 3}–10{sup 4} s{sup −1} in a compression Kolsky bar (split Hopkinson pressure bar) apparatus to obtain in situ diffraction patterns with exposures as short as 70 ns. This approach employs moderate x-ray energies (10–20 keV) and is well suited to weakly absorbing materials such as magnesium alloys. The second technique is useful for more strongly absorbing materials, and uses high-energy x-rays (86 keV) and a fast shutter synchronized with the Kolsky bar to produce short (∼40 μs) pulses timed with the arrival of the strain pulse at the specimen, recording the diffraction pattern on a large-format amorphous silicon detector. For both techniques we present sample data demonstrating the ability of these techniques to characterize elastic strains and polycrystalline texture as a function of time during high-rate deformation.

  17. X-ray tomography system to investigate granular materials during mechanical loading

    CERN Document Server

    Athanassiadis, Athanasios G; Sidky, Emil; Pelizzari, Charles; Pan, Xiaochuan; Jaeger, Heinrich M

    2014-01-01

    We integrate a small and portable medical x-ray device with mechanical testing equipment to enable in-situ, non-invasive measurements of a granular material's response to mechanical loading. We employ an orthopedic C-arm as the x-ray source and detector to image samples mounted in the materials tester. We discuss the design of a custom rotation stage, which allows for sample rotation and tomographic reconstruction under applied compressive stress. We then discuss the calibration of the system for 3d computed tomography, as well as the subsequent image reconstruction process. Using this system to reconstruct packings of 3d-printed particles, we resolve packing features with 0.52 mm resolution in a (60 mm)$^3$ field of view. By analyzing the performance bounds of the system, we demonstrate that the reconstructions exhibit only moderate noise.

  18. X-ray tomography system to investigate granular materials during mechanical loading

    Science.gov (United States)

    Athanassiadis, Athanasios G.; La Rivière, Patrick J.; Sidky, Emil; Pelizzari, Charles; Pan, Xiaochuan; Jaeger, Heinrich M.

    2014-08-01

    We integrate a small and portable medical x-ray device with mechanical testing equipment to enable in situ, non-invasive measurements of a granular material's response to mechanical loading. We employ an orthopedic C-arm as the x-ray source and detector to image samples mounted in the materials tester. We discuss the design of a custom rotation stage, which allows for sample rotation and tomographic reconstruction under applied compressive stress. We then discuss the calibration of the system for 3D computed tomography, as well as the subsequent image reconstruction process. Using this system to reconstruct packings of 3D-printed particles, we resolve packing features with 0.52 mm resolution in a (60 mm)3 field of view. By analyzing the performance bounds of the system, we demonstrate that the reconstructions exhibit only moderate noise.

  19. X-ray tomography system to investigate granular materials during mechanical loading

    Energy Technology Data Exchange (ETDEWEB)

    Athanassiadis, Athanasios G. [James Franck Institute and Department of Physics, The University of Chicago, Chicago, Illinois 60637 (United States); Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); La Rivière, Patrick J.; Sidky, Emil; Pan, Xiaochuan [Department of Radiology, The University of Chicago, Chicago, Illinois 60637 (United States); Pelizzari, Charles [Department of Radiation and Cellular Oncology, The University of Chicago, Chicago, Illinois 60637 (United States); Jaeger, Heinrich M., E-mail: h-jaeger@uchicago.edu [James Franck Institute and Department of Physics, The University of Chicago, Chicago, Illinois 60637 (United States)

    2014-08-15

    We integrate a small and portable medical x-ray device with mechanical testing equipment to enable in situ, non-invasive measurements of a granular material's response to mechanical loading. We employ an orthopedic C-arm as the x-ray source and detector to image samples mounted in the materials tester. We discuss the design of a custom rotation stage, which allows for sample rotation and tomographic reconstruction under applied compressive stress. We then discuss the calibration of the system for 3D computed tomography, as well as the subsequent image reconstruction process. Using this system to reconstruct packings of 3D-printed particles, we resolve packing features with 0.52 mm resolution in a (60 mm){sup 3} field of view. By analyzing the performance bounds of the system, we demonstrate that the reconstructions exhibit only moderate noise.

  20. Demonstration of a non-contact x-ray source using an inductively heated pyroelectric accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Klopfer, Michael; Satchouk, Vladimir; Cao, Anh; Wolowiec, Thomas; Alivov, Yahya; Molloi, Sabee, E-mail: symolloi@uci.edu

    2015-04-11

    X-ray emission from pyroelectric sources can be produced through non-contact thermal cycling using induction heating. In this study, we demonstrated a proof of concept non-contact x-ray source powered via induction heating. An induction heater operating at 62.5 kHz provided a total of 6.5 W of delivered peak thermal power with 140 V DC of driving voltage. The heat was applied to a ferrous substrate mechanically coupled to a cubic 1 cm{sup 3} Lithium Niobate (LiNbO{sub 3}) pyroelectric crystal maintained in a 3–12 mTorr vacuum. The maximum temperature reached was 175 °C in 86 s of heating. The cooling cycle began immediately after heating and was provided by passive radiative cooling. The total combined cycle time was 250 s. x-ray photons were produced and analyzed in both heating and cooling phases. Maximum photon energies of 59 keV and 55 keV were observed during heating and cooling, respectively. Non-contact devices such as this, may find applications in cancer therapy (brachytherapy), non-destructive testing, medical imaging, and physics education fields.

  1. Experimental investigation of X-ray spectral absorption coefficients in heated Al and Ge on the Iskra-5 laser facility

    Energy Technology Data Exchange (ETDEWEB)

    Bondarenko, S V; Garanin, Sergey G; Zhidkov, N V; Pinegin, A V; Suslov, N A [Russian Federal Nuclear Center ' All-Russian Research Institute of Experimental Physics' , Sarov, Nizhnii Novgorod region (Russian Federation)

    2012-01-31

    We set forth the data of experimental investigation of X-ray spectral absorption coefficients in the 1.1 - 1.6 keV photon energy range for Al and Ge specimens bulk heated by soft X-ray radiation. Two experimental techniques are described: with the use of one facility channel and the heating of specimens by the X-ray radiation from a plane burnthrough target, as well as with the use of four channels and the heating by the radiation from two cylindrical targets with internal input of laser radiation. The X-ray radiation absorption coefficients were studied by way of transmission absorption spectroscopy using backlighting X-ray radiation from a point source. The results of investigation of X-ray spectral absorption coefficients on the 1s - 2p transitions in Al atoms and the 2p - 3d transitions in Ge atoms are presented.

  2. Experimental investigation of X-ray spectral absorption coefficients in heated Al and Ge on the Iskra-5 laser facility

    Science.gov (United States)

    Bondarenko, S. V.; Garanin, Sergey G.; Zhidkov, N. V.; Pinegin, A. V.; Suslov, N. A.

    2012-01-01

    We set forth the data of experimental investigation of X-ray spectral absorption coefficients in the 1.1 — 1.6 keV photon energy range for Al and Ge specimens bulk heated by soft X-ray radiation. Two experimental techniques are described: with the use of one facility channel and the heating of specimens by the X-ray radiation from a plane burnthrough target, as well as with the use of four channels and the heating by the radiation from two cylindrical targets with internal input of laser radiation. The X-ray radiation absorption coefficients were studied by way of transmission absorption spectroscopy using backlighting X-ray radiation from a point source. The results of investigation of X-ray spectral absorption coefficients on the 1s — 2p transitions in Al atoms and the 2p — 3d transitions in Ge atoms are presented.

  3. Microscale electromagnetic heating in heterogeneous energetic materials based on X-ray CT imaging

    CERN Document Server

    Kort-Kamp, W J M; Ionita, A; Glover, B B; Duque, A L Higginbotham; Perry, W L; Patterson, B M; Dalvit, D A R; Moore, D S

    2015-01-01

    Electromagnetic stimulation of energetic materials provides a noninvasive and nondestructive tool for detecting and identifying explosives. We combine structural information based on X-ray computed tomography, experimental dielectric data, and electromagnetic full-wave simulations, to study microscale electromagnetic heating of realistic three-dimensional heterogeneous explosives. We analyze the formation of electromagnetic hot spots and thermal gradients in the explosive-binder meso-structures, and compare the heating rate for various binder systems.

  4. Study of caprine bones after moist and dry heat processes by X-ray diffraction

    Energy Technology Data Exchange (ETDEWEB)

    Barbosa, Caroline M., E-mail: carolmattosb@yahoo.com.br [Instituto de Arqueologia Brasileira (IAB), Belford Roxo, RJ (Brazil); Azeredo, Soraia R.; Lopes, Ricardo T., E-mail: soraia@lin.ufrj.br [Coordenacao dos Programas de Pos-Graduacao em Engenharia (COPPE/LIN/UFRJ), Rio de Janeiro, RJ (Brazil). Laboratorio de Instrumentacao Nuclear; Souza, Sheila M.F.M de, E-mail: sferraz@ensp.fiocruz.br [Fundacao Oswaldo Cruz (ENSP/FIOCRUZ), Rio de Janeiro, RJ (Brazil). Escola Nacional de Saude Publica Sergio Arouca

    2013-07-01

    Bone tissue is a biological material composed of hydroxyapatite (HAp) and collagen matrix. The bone X-ray diffraction (XRD) pattern presents characteristics of the hydroxyapatite crystallography planes. This paper presents the characterization by X-ray diffraction of caprine bone powder pattern and the comparison of this pattern with moist or dry heat cooked bone patterns. The parameters chosen to characterize the X-ray diffraction peaks were: angular position (2θ), full width at half maximumt (FWHM), and relative intensity (I{sub rel}). The X-ray diffraction patterns were obtained with a Shimadzu XRD-6000 diffractometer. The caprine bone XRD pattern revealed a significant correlation of several crystallographic parameters (lattice data) with hydroxyapatite. The profiles of the three bone types analyzed presented differences. The study showed as small angular displacement (decrease of the 2θ angle) of some peaks was observed after moist and dry heat cooking processes. The characterization of bone tissue aimed to contribute to future analysis in the field of archeology. (author)

  5. Parametrizing Impulsive X-ray Heating with a Cumulative Initial-Temperature Distribution

    CERN Document Server

    Gayley, K G

    2014-01-01

    In collisional ionization equilibrium (CIE), the X-ray spectrum from a plasma depends on the distribution of emission measure over temperature (DEM). Due to the well-known ill conditioning problem, no precisely resolved DEM can be inverted directly from the spectrum, so often only a gross parametrization of the DEM is used to approximate the data, in hopes that the parametrization can provide useful model-independent constraints on the heating process. However, ill conditioning also introduces ambiguity into the various different parametrizations that could approximate the data, which may spoil the perceived advantages of model independence. Thus, this paper instead suggests a single parametrization for both the heating mechanism and the X-ray sources, based on a model of impulsive heating followed by complete cooling. This approach is similar to a ``cooling flow'' approach, but allows injection at multiple initial temperatures, and applies even when the steady state is distribution of different shock strengt...

  6. Hard X-Ray Constraints on Small-Scale Coronal Heating Events

    Science.gov (United States)

    Marsh, Andrew; Smith, David M.; Glesener, Lindsay; Klimchuk, James A.; Bradshaw, Stephen; Hannah, Iain; Vievering, Juliana; Ishikawa, Shin-Nosuke; Krucker, Sam; Christe, Steven

    2017-08-01

    A large body of evidence suggests that the solar corona is heated impulsively. Small-scale heating events known as nanoflares may be ubiquitous in quiet and active regions of the Sun. Hard X-ray (HXR) observations with unprecedented sensitivity >3 keV have recently been enabled through the use of focusing optics. We analyze active region spectra from the FOXSI-2 sounding rocket and the NuSTAR satellite to constrain the physical properties of nanoflares simulated with the EBTEL field-line-averaged hydrodynamics code. We model a wide range of X-ray spectra by varying the nanoflare heating amplitude, duration, delay time, and filling factor. Additional constraints on the nanoflare parameter space are determined from energy constraints and EUV/SXR data.

  7. Evaluation of observed blast loading effects on NIF x-ray diagnostic collimators.

    Science.gov (United States)

    Masters, N D; Fisher, A; Kalantar, D; Prasad, R; Stölken, J S; Wlodarczyk, C

    2014-11-01

    We present the "debris wind" models used to estimate the impulsive load to which x-ray diagnostics and other structures are subject during National Ignition Facility experiments. These models are used as part of the engineering design process. Isotropic models, based on simulations or simplified "expanding shell" models, are augmented by debris wind multipliers to account for directional anisotropy. We present improvements to these multipliers based on measurements of the permanent deflections of diagnostic components: 4× for the polar direction and 2× within the equatorial plane-the latter relaxing the previous heuristic debris wind multiplier.

  8. Lyalpha versus X-ray heating in the high-z IGM

    CERN Document Server

    Ciardi, Benedetta; Di Matteo, Tiziana

    2009-01-01

    In this paper we examine the effect of X-ray and Lyalpha photons on the intergalactic medium temperature. We calculate the photon production from a population of stars and micro-quasars in a set of cosmological hydrodynamic simulations which self-consistently follow the dark matter dynamics, radiative processes as well as star formation, black hole growth and associated feedback processes. We find that, (i) IGM heating is always dominated by X-rays unless the Lyalpha photon contribution from stars in objects with mass M<10^8 Msun becomes significantly enhanced with respect to the X-ray contribution from BHs in the same halo (which we do not directly model). (ii) Without overproducing the unresolved X-ray background, the gas temperature becomes larger than the CMB temperature, and thus an associated 21 cm signal should be expected in emission, at z<11.5. We discuss how in such a scenario the transition redshift between a 21 cm signal in absorption and in emission could be used to constraint BHs accretion...

  9. X-Ray Micro-Tomography Applied to Nasa's Materials Research: Heat Shields, Parachutes and Asteroids

    Science.gov (United States)

    Panerai, Francesco; Borner, Arnaud; Ferguson, Joseph C.; Mansour, Nagi N.; Stern, Eric C.; Barnard, Harold S.; Macdowell, Alastair A.; Parkinson, Dilworth Y.

    2017-01-01

    X-ray micro-tomography is used to support the research on materials carried out at NASA Ames Research Center. The technique is applied to a variety of applications, including the ability to characterize heat shield materials for planetary entry, to study the Earth- impacting asteroids, and to improve broadcloths of spacecraft parachutes. From micro-tomography images, relevant morphological and transport properties are determined and validated against experimental data.

  10. Non-thermal electron populations in microwave heated plasmas investigated with X-ray detectors

    Energy Technology Data Exchange (ETDEWEB)

    Belapure, Jaydeep Sanjay

    2013-04-15

    An investigation of the generation and dynamics of superthermal electrons in fusion plasma is carried out. A SDD+CsI(Tl) based X-ray diagnostic is constructed, characterized and installed at ASDEX Upgrade. In various plasma heating power and densities, the fraction and the energy distribution of the superthermal electrons is obtained by a bi-Maxwellian model and compared with Fokker-Planck simulations.

  11. X-Ray Computed Tomography Inspection of the Stardust Heat Shield

    Science.gov (United States)

    McNamara, Karen M.; Schneberk, Daniel J.; Empey, Daniel M.; Koshti, Ajay; Pugel, D. Elizabeth; Cozmuta, Ioana; Stackpoole, Mairead; Ruffino, Norman P.; Pompa, Eddie C.; Oliveras, Ovidio; hide

    2010-01-01

    The "Stardust" heat shield, composed of a PICA (Phenolic Impregnated Carbon Ablator) Thermal Protection System (TPS), bonded to a composite aeroshell, contains important features which chronicle its time in space as well as re-entry. To guide the further study of the Stardust heat shield, NASA reviewed a number of techniques for inspection of the article. The goals of the inspection were: 1) to establish the material characteristics of the shield and shield components, 2) record the dimensions of shield components and assembly as compared with the pre-flight condition, 3) provide flight infonnation for validation and verification of the FIAT ablation code and PICA material property model and 4) through the evaluation of the shield material provide input to future missions which employ similar materials. Industrial X-Ray Computed Tomography (CT) is a 3D inspection technology which can provide infonnation on material integrity, material properties (density) and dimensional measurements of the heat shield components. Computed tomographic volumetric inspections can generate a dimensionally correct, quantitatively accurate volume of the shield assembly. Because of the capabilities offered by X-ray CT, NASA chose to use this method to evaluate the Stardust heat shield. Personnel at NASA Johnson Space Center (JSC) and Lawrence Livermore National Labs (LLNL) recently performed a full scan of the Stardust heat shield using a newly installed X-ray CT system at JSC. This paper briefly discusses the technology used and then presents the following results: 1. CT scans derived dimensions and their comparisons with as-built dimensions anchored with data obtained from samples cut from the heat shield; 2. Measured density variation, char layer thickness, recession and bond line (the adhesive layer between the PICA and the aeroshell) integrity; 3. FIAT predicted recession, density and char layer profiles as well as bondline temperatures Finally suggestions are made as to future uses

  12. Kinetic and radiation-hydrodynamic modeling of x-ray heating in laboratory photoionized plasmas

    Science.gov (United States)

    Mancini, Roberto

    2017-06-01

    In experiments performed at the Z facility of Sandia National Laboratories a cm-scale cell filled with neon gas was driven by the burst of broadband x-rays emitted at the collapse of a wire-array z-pinch turning the gas into a photoionized plasma. Transmission spectroscopy of a narrowband portion of the x-ray flux was used to diagnose the plasma. The data show a highly-ionized neon plasma with a rich line absorption spectrum that permits the extraction of the ionization distribution among Be-, Li-, He- and H-like ions. Analysis of the spectra produced atomic ground and low excited state areal densities in these ions, and from the ratio of first-excited to ground state populations in Li-like neon a temperature of 19±4eV was extracted to characterize the x-ray heating of the plasma. To interpret this observation, we have performed data-constrained view-factor calculations of the spectral distribution of the x-ray drive, self-consistent modeling of electron and atomic kinetics, and radiation-hydrodynamic simulations. For the conditions of the experiment, the electron distribution thermalizes quickly, has a negligible high-energy tail, and is very well approximated by a single Maxwellian distribution. Radiation-hydrodynamic simulations with either LTE or NLTE (i.e. non-equilibrium) atomic physics provide a more complete modeling of the experiment. We found that in order to compute electron temperatures consistent with observation inline non-equilibrium collisional-radiative neon atomic kinetics needs to be taken into account. We discuss the details of LTE and NLTE simulations, and the impact of atomic physics on the radiation heating and cooling rates that determine the plasma temperature. This work was sponsored in part by DOE Office of Science Grant DE-SC0014451, and the Z Facility Fundamental Science Program of SNL.

  13. Diaplectic Glass Content in Experimentally Shock-loaded Quartz Determined by X-Ray Powder Diffraction

    Science.gov (United States)

    Skala, R.; Hoerz, F.; Langenhorst, F.

    2003-01-01

    Quartz is the most common mineral of terrestrial crustal rocks and thus a widespread indicator for impact cratering and associated shock metamorphism. Planar deformation features (PDFs) are among the most prominent and diagnostic shock features in quartz and they represent thin lamellae of glass that formed via solid-state transformations. This socalled 'diaplectic' glass becomes pervasive at higher pressures and results in optically isotropic and X-ray-amorphous phases that resemble texturally the original quartz grains (without evidence of melt flow). In the past, it has been shown that the amount of this amorphous material in experimentally shock-loaded quartz correlates with peak shock pressure. Both reports derive the glass content from density measurements of individual crystals employing the equation X(%) = (rho(sub x) - rho(sub 0))/(rho(sub x) - rho(sub gl)), where x and 0 stands for X-ray and average (optical) density, respectively. The density of glass, rho(sub gl), was adopted as 2.2 g/cu cm. Though the same procedures had been applied, the resulting glass content differs significantly among the above studies. In the present study, we are using a new approach based solely on the integral intensity of a single, carefully selected reflection in the XRD pattern, and we will compare our data to those reported in the literature.

  14. High heat flux x-ray monochromators: What are the limits?

    Energy Technology Data Exchange (ETDEWEB)

    Rogers, C.S.

    1997-06-01

    First optical elements at third-generation, hard x-ray synchrotrons, such as the Advanced Photon Source (APS), are subjected to immense heat fluxes. The optical elements include crystal monochromators, multilayers and mirrors. This paper presents a mathematical model of the thermal strain of a three-layer (faceplate, heat exchanger, and baseplate), cylindrical optic subjected to narrow beam of uniform heat flux. This model is used to calculate the strain gradient of a liquid-gallium-cooled x-ray monochromator previously tested on an undulator at the Cornell High Energy Synchrotron Source (CHESS). The resulting thermally broadened rocking curves are calculated and compared to experimental data. The calculated rocking curve widths agree to within a few percent of the measured values over the entire current range tested (0 to 60 mA). The thermal strain gradient under the beam footprint varies linearly with the heat flux and the ratio of the thermal expansion coefficient to the thermal conductivity. The strain gradient is insensitive to the heat exchanger properties and the optic geometry. This formulation provides direct insight into the governing parameters, greatly reduces the analysis time, and provides a measure of the ultimate performance of a given monochromator.

  15. The Jet-Heated X-ray Filament in the Centaurus A Northern Middle Radio Lobe

    CERN Document Server

    Kraft, R P; Hardcastle, M J; Birkinshaw, M; Croston, J H; Jones, C; Nulsen, P E J; Worrall, D M; Murray, S S

    2009-01-01

    We present results from a 40 ks {\\em XMM-Newton} observation of the X-ray filament coincident with the southeast edge of the Centaurus A Northern Middle Radio Lobe (NML). We find that the X-ray filament consists of five spatially resolved X-ray knots embedded in a continuous diffuse bridge. The spectrum of each knot is well fitted by a thermal model with temperatures ranging from 0.3-0.7 keV and subsolar elemental abundances. In four of the five knots, non-thermal models are a poor fit to the spectra, conclusively ruling out synchrotron or IC/CMB mechanisms for their emission. The internal pressures of the knots exceed that of the ambient ISM or the equipartition pressure of the NML by more than an order of magnitude, demonstrating that they must be short lived ($\\sim3\\times10^6$ yrs). Based on energetic arguments, it is implausible that these knots have been ionized by the beamed flux from the active galactic nucleus of Cen A or that they have been shock-heated by supersonic inflation of the NML. In our view...

  16. X-ray excited luminescence of polystyrene composites loaded with SrF2 nanoparticles

    Science.gov (United States)

    Demkiv, T. M.; Halyatkin, O. O.; Vistovskyy, V. V.; Hevyk, V. B.; Yakibchuk, P. M.; Gektin, A. V.; Voloshinovskii, A. S.

    2017-03-01

    The polystyrene film nanocomposites of 0.3 mm thickness with embedded SrF2 nanoparticles up to 40 wt% have been synthesized. The luminescent and kinetic properties of the polystyrene composites with embedded SrF2 nanoparticles upon the pulse X-ray excitation have been investigated. The luminescence intensity of the pure polystyrene scintillator film significantly increases when it is loaded with the inorganic SrF2 nanoparticles. The film nanocomposites show fast (∼2.8 ns) and slow (∼700 ns) luminescence decay components typical for a luminescence of polystyrene activators (p-Terphenyl and POPOP) and SrF2 nanoparticles, respectively. It is revealed that the fast decay luminescence component of the polystyrene composites is caused by the excitation of polystyrene by the photoelectrons escaped from the nanoparticles due to photoeffect, and the slow component is caused by reabsorption of the self-trapped exciton luminescence of SrF2 nanoparticles by polystyrene.

  17. Heating of X-Ray Hot Gas in Groups by Blast Waves

    CERN Document Server

    Fujita, Y

    2001-01-01

    In order to find the conditions which determine whether X-Ray hot gas in galaxy groups (intragroup gas; IGG) is heated externally or internally, we investigate the evolution of blast waves in galaxy groups growing on a hierarchical clustering scenario. We find that the blast waves driven by quasars are confined in groups and heat the IGG internally at z~ 1, they expel the IGG from groups; the expelled gas may fall back into the groups later as externally heated gas. Moreover, this may explain the observed low metal abundance of IGG. For blast waves driven by strong starbursts, the shift of the fate of blast waves occurs at z~ 3. On the other hand, although blast waves driven by weak starbursts do not expel IGG from groups, the heating efficiency decreases at z>~ 3 because of radiative cooling. It will be useful to compare these results with XMM-Newton observations.

  18. X-ray scattering and spectroscopy studies on diesel soot from oxygenated fuel under various engine load conditions

    Science.gov (United States)

    Braun, Andreas; Shah, N.; Huggins, Frank E.; Kelly, K.E.; Sarofim, A.; Jacobsen, C.; Wirick, S.; Francis, H.; Ilavsky, J.; Thomas, G.E.; Huffman, G.P.

    2005-01-01

    Diesel soot from reference diesel fuel and oxygenated fuel under idle and load engine conditions was investigated with X-ray scattering and X-ray carbon K-edge absorption spectroscopy. Up to five characteristic size ranges were found. Idle soot was generally found to have larger primary particles and aggregates but smaller crystallites, than load soot. Load soot has a higher degree of crystallinity than idle soot. Adding oxygenates to diesel fuel enhanced differences in the characteristics of diesel soot, or even reversed them. Aromaticity of idle soot from oxygenated diesel fuel was significantly larger than from the corresponding load soot. Carbon near-edge X-ray absorption fine structure (NEXAFS) spectroscopy was applied to gather information about the presence of relative amounts of carbon double bonds (CC, CO) and carbon single bonds (C-H, C-OH, COOH). Using scanning X-ray transmission microspectroscopy (STXM), the relative amounts of these carbon bond states were shown to vary spatially over distances approximately 50 to 100 nm. The results from the X-ray techniques are supported by thermo-gravimetry analysis and high-resolution transmission electron microscopy. ?? 2005 Elsevier Ltd. All rights reserved.

  19. Heating the intergalactic medium by X-rays from population III binaries in high-redshift galaxies

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Hao; Norman, Michael L. [Center for Astrophysics and Space Sciences, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093 (United States); Ahn, Kyungjin [Department of Earth Science Education, Chosun University, Gwangju 501-759 (Korea, Republic of); Wise, John H. [Center for Relativistic Astrophysics, School of Physics, Georgia Institute of Technology, 837 State Street, Atlanta, GA 30332 (United States); O' Shea, Brian W., E-mail: hxu@ucsd.edu, E-mail: mlnorman@ucsd.edu, E-mail: kjahn@chosun.ac.kr, E-mail: jwise@gatech.edu, E-mail: oshea@msu.edu [Lyman Briggs College and Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824 (United States)

    2014-08-20

    Due to their long mean free path, X-rays are expected to have an important impact on cosmic reionization by heating and ionizing the intergalactic medium (IGM) on large scales, especially after simulations have suggested that Population III (Pop III) stars may form in pairs at redshifts as high as 20-30. We use the Pop III distribution and evolution from a self-consistent cosmological radiation hydrodynamic simulation of the formation of the first galaxies and a simple Pop III X-ray binary model to estimate their X-ray output in a high-density region larger than 100 comoving (Mpc){sup 3}. We then combine three different methods—ray tracing, a one-zone model, and X-ray background modeling—to investigate the X-ray propagation, intensity distribution, and long-term effects on the IGM thermal and ionization state. The efficiency and morphology of photoheating and photoionization are dependent on the photon energies. The sub-kiloelectronvolt X-rays only impact the IGM near the sources, while the kiloelectronvolt photons contribute significantly to the X-ray background and heat and ionize the IGM smoothly. The X-rays just below 1 keV are most efficient in heating and ionizing the IGM. We find that the IGM might be heated to over 100 K by z = 10 and the high-density source region might reach 10{sup 4} K, limited by atomic hydrogen cooling. This may be important for predicting the 21 cm neutral hydrogen signals. On the other hand, the free electrons from X-ray ionizations are not enough to contribute significantly to the optical depth of the cosmic microwave background to the Thomson scattering.

  20. Conversion Efficiency of Kilovolt X- Ray Line Emission in Laser-heated NaF Plasma

    Institute of Scientific and Technical Information of China (English)

    孔令华; 淳于书泰; 何绍堂; 陈涵德; 杨向东; 李孝昌; 王永国

    1994-01-01

    This paper reports the theoretical and experimental work on converting focused Nd-glass laser radiation of LI-11 facility into kilovolt X-ray line emission in laser-heated NaF plasma.This conversion efficiency ε turns out to he in the range from 0.2% to 1% for the laser (λ=1.06μm) power density changing from 10×1013 to 3.5×1013 W/cm2 The relationship between ε and λ has also been discussed.Simultaneously,theoretical results are compared with the experimental.

  1. EUV & X-ray observations of microflare heating of AR12333

    Science.gov (United States)

    Hannah, I. G.; Wright, P. J.; Grefenstette, B.; Glesener, L.; Hudson, H. S.; Smith, D. M.; Krucker, S.; Marsh, A.; White, S. M.

    2015-12-01

    We present a study of the heating in AR12333 due to small microflares between 10:30 and 13:30UT on 29 April 2015. This region is well observed in EUV by the Solar Dynamics Observatory/Atmospheric Imaging Assembly (SDO/AIA) as well as Hinode's X-ray Telescope (XRT) operating in a higher cadence mode, switching through the five thicker filters (sensitive to the higher temperature range). The Hinode observations were a coordinated campaign with the NuSTAR hard X-ray focusing optics telescope (Harrison et al. 2013). NuSTAR was conducting a full disk mosaic observation of the Sun and caught AR12333 several times, providing imaging spectroscopy >2 keV. We investigate the heating in the active region due to several small microflares (about A1-Class). These were visible with the thicker XRT filters and only clear in EUV once the FeXVIII component was extracted from SDO/AIA 94Å, indicating heating primarily >3MK. Using the regularized inversion method of Hannah & Kontar 2012, we recover the DEM from the SDO/AIA and Hinode/XRT data and compare this to the thermal characteristics derived from NuSTAR.

  2. Three stages of copper accumulation in hepatocellular lysosomes: X-ray microanalysis of copper-loaded golden hamsters.

    OpenAIRE

    Yagi, A.; Hayashi, H; Higuchi, T.; Hishida, N.; Sakamoto, N.

    1992-01-01

    Male golden hamsters were loaded with copper by supplying them for up to 12 weeks with drinking water containing 0.5% cupric acetate. The copper feeding increased hepatic copper to widely varying levels. Energy dispersive X-ray microanalysis could always identify a copper-sulphur complex in the hepatocyte lysosomes of copper-loaded hamsters and the X-ray intensity of copper was found to be a reliable parameter to measure in-situ copper accumulation. Combining this parameter with the copper bi...

  3. Imaging of drug loading distributions in individual microspheres of calcium silicate hydrate - an X-ray spectromicroscopy study

    Science.gov (United States)

    Guo, Xiaoxuan; Wang, Zhiqiang; Wu, Jin; Wang, Jian; Zhu, Ying-Jie; Sham, Tsun-Kong

    2015-04-01

    Imaging is one of the most direct and ideal ways to track drug loading distributions in drug carriers on the molecular level, which will facilitate the optimization of drug carriers and drug loading capacities. Herein, we report the mapping of an individual mesoporous calcium silicate hydrate (CSH) microsphere before and after the loading of ibuprofen (IBU) and the interactions between drug carriers and drug molecules simultaneously by scanning transmission X-ray microscopy (STXM). Nanoscaled X-ray absorption near edge structure (XANES) spectroscopy clearly indicates that IBU is bonded to calcium and silicate sites via carboxylic acid groups. More importantly, STXM has been successfully used to determine the absolute thickness of IBU, revealing its distribution in the CSH microsphere.Imaging is one of the most direct and ideal ways to track drug loading distributions in drug carriers on the molecular level, which will facilitate the optimization of drug carriers and drug loading capacities. Herein, we report the mapping of an individual mesoporous calcium silicate hydrate (CSH) microsphere before and after the loading of ibuprofen (IBU) and the interactions between drug carriers and drug molecules simultaneously by scanning transmission X-ray microscopy (STXM). Nanoscaled X-ray absorption near edge structure (XANES) spectroscopy clearly indicates that IBU is bonded to calcium and silicate sites via carboxylic acid groups. More importantly, STXM has been successfully used to determine the absolute thickness of IBU, revealing its distribution in the CSH microsphere. Electronic supplementary information (ESI) available. See DOI: 10.1039/c4nr07471h

  4. Soft x-ray shock loading and momentum coupling in meteorite and planetary materials.

    Energy Technology Data Exchange (ETDEWEB)

    Lawrence, R. Jeffery; Remo, John L. (Harvard University, Cambridge, MA); Furnish, Michael David

    2010-12-01

    X-ray momentum coupling coefficients, C{sub M}, were determined by measuring stress waveforms in planetary materials subjected to impulsive radiation loading from the Sandia National Laboratories Z-machine. Results from the velocity interferometry (VISAR) diagnostic provided limited equation-of-state data as well. Targets were iron and stone meteorites, magnesium rich olivine (dunite) solid and powder ({approx}5--300 {mu}m), and Si, Al, and Fe calibration targets. All samples were {approx}1 mm thick and, except for Si, backed by LiF single-crystal windows. The x-ray spectrum included a combination of thermal radiation (blackbody 170--237 eV) and line emissions from the pinch material (Cu, Ni, Al, or stainless steel). Target fluences 0.4--1.7 kJ/cm{sup 2} at intensities 43--260 GW/cm{sup 2} produced front surface plasma pressures 2.6--12.4 GPa. Stress waves driven into the samples were attenuating due to the short ({approx}5 ns) duration of the drive pulse. Attenuating wave impulse is constant allowing accurate C{sub M} measurements provided mechanical impedance mismatch between samples and the window are known. Impedance-corrected C{sub M} determined from rear-surface motion was 1.9--3.1 x 10{sup -5} s/m for stony meteorites, 2.7 and 0.5 x 10{sup -5} s/m for solid and powdered dunite, 0.8--1.4 x 10{sup -5}.

  5. Heat transfer simulation and thermal measurements of microfabricated x-ray transparent heater stages.

    Science.gov (United States)

    Baldasseroni, C; Queen, D R; Cooke, David W; Maize, K; Shakouri, A; Hellman, F

    2011-09-01

    A microfabricated amorphous silicon nitride membrane-based nanocalorimeter is proposed to be suitable for an x-ray transparent sample platform with low power heating and built-in temperature sensing. In this work, thermal characterization in both air and vacuum are analyzed experimentally and via simulation. Infrared microscopy and thermoreflectance microscopy are used for thermal imaging of the sample area in air. While a reasonably large isothermal area is found on the sample area, the temperature homogeneity of the entire sample area is low, limiting use of the device as a heater stage in air or other gases. A simulation model that includes conduction, as well as radiation and convection heat loss, is presented with radiation and convection parameters determined experimentally. Simulated temperature distributions show that the homogeneity can be improved by using a thicker thermal conduction layer or reducing the pressure of the gas in the environment but neither are good solutions for the proposed use. A new simple design that has improved temperature homogeneity and a larger isothermal area while maintaining a thin thermal conduction layer is proposed and fabricated. This new design enables applications in transmission x-ray microscopes and spectroscopy setups at atmospheric pressure. © 2011 American Institute of Physics

  6. Compton Heating of the Intergalactic Medium by the Hard X-ray Background

    CERN Document Server

    Madau, P; Madau, Piero; Efstathiou, George

    1999-01-01

    High-resolution hydrodynamics simulations of the Ly-alpha forest in cold dark matter dominated cosmologies appear to predict line widths that are substantially narrower than those observed. Here we point out that Compton heating of the intergalactic gas by the hard X-ray background (XRB), an effect neglected in all previous investigations, may resolve this discrepancy. The rate of gain in thermal energy by Compton scattering will dominate over the energy input from hydrogen photoionization if the XRB energy density is 0.2x/ times higher than the energy density of the UV background at a given epoch, where x is the hydrogen neutral fraction in units of 1e-6 and is the mean X-ray photon energy in units of m_ec^2. The numerical integration of the time-dependent rate equations shows that the intergalactic medium approaches a temperature of about 20,000 K at z>3 in popular models for the redshift evolution of the extragalactic background radiation. The importance of Compton heating can be tested experimentally by ...

  7. A reaction cell with sample laser heating for in situ soft X-ray absorption spectroscopy studies under environmental conditions.

    Science.gov (United States)

    Escudero, Carlos; Jiang, Peng; Pach, Elzbieta; Borondics, Ferenc; West, Mark W; Tuxen, Anders; Chintapalli, Mahati; Carenco, Sophie; Guo, Jinghua; Salmeron, Miquel

    2013-05-01

    A miniature (1 ml volume) reaction cell with transparent X-ray windows and laser heating of the sample has been designed to conduct X-ray absorption spectroscopy studies of materials in the presence of gases at atmospheric pressures. Heating by laser solves the problems associated with the presence of reactive gases interacting with hot filaments used in resistive heating methods. It also facilitates collection of a small total electron yield signal by eliminating interference with heating current leakage and ground loops. The excellent operation of the cell is demonstrated with examples of CO and H2 Fischer-Tropsch reactions on Co nanoparticles.

  8. Shrink tape technique for heat-forming aluminum substrates for thin foil x-ray mirrors and the Neutron Star Interior Composition Explorer x-ray concentrators

    Science.gov (United States)

    Balsamo, Erin; Gendreau, Keith; Okajima, Takashi; Soong, Yang; Serlemitsos, Peter; Jalota, Lalit; Kenyon, Steven; Spartana, Nicholas; Fickau, David; Koenecke, Richard

    2016-01-01

    Consistent improvements in the design and fabrication of thin-foil, epoxy-replicated x-ray mirrors for astronomical telescopes have yielded increasingly higher quality and more precise astrophysical data. The Neutron Star Interior Composition Explorer (NICER) x-ray timing mission optics continues this tradition and introduces design elements that promise even more accurate measurements and precise astrophysical parameters. The singly reflecting concentrators have a curved axial profile to improve photon concentration and a sturdy full shell structure for enhanced module stability. These design elements introduced the challenge of reliably forming mirror substrates at an acceptable production rate. By developing a technique using heat shrink tape to compress and conform thin aluminum mirror substrates to shaping mandrels, production rate improved with successful fabrication. The technique's efficiency was analyzed by measuring hundreds of substrate profiles postforming, performance testing completely assembled concentrators composed of every size substrate, and comparing the results to simulated fabrication scenarios. On average, the profiles were copied within 4.6±3.7%. These measurements and the overall success of NICER's optics, via ground calibration, have shown that the heat-shrink tape method is reliable, repeatable, and could be used in future missions to increase production rate and improve performance.

  9. X-RAY SOURCE HEIGHTS IN A SOLAR FLARE: THICK-TARGET VERSUS THERMAL CONDUCTION FRONT HEATING

    Energy Technology Data Exchange (ETDEWEB)

    Reep, J. W. [National Research Council Post-Doc Program, Naval Research Laboratory, Washington, DC 20375 (United States); Bradshaw, S. J. [Department of Physics and Astronomy, Rice University, Houston, TX 77005 (United States); Holman, G. D., E-mail: jeffrey.reep.ctr@nrl.navy.mil, E-mail: stephen.bradshaw@rice.edu, E-mail: gordon.d.holman@nasa.gov [Solar Physics Laboratory, Code 671, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States)

    2016-02-10

    Observations of solar flares with RHESSI have shown X-ray sources traveling along flaring loops, from the corona down to the chromosphere and back up. The 2002 November 28 C1.1 flare, first observed with RHESSI by Sui et al. and quantitatively analyzed by O’Flannagain et al., very clearly shows this behavior. By employing numerical experiments, we use these observations of X-ray source height motions as a constraint to distinguish between heating due to a non-thermal electron beam and in situ energy deposition in the corona. We find that both heating scenarios can reproduce the observed light curves, but our results favor non-thermal heating. In situ heating is inconsistent with the observed X-ray source morphology and always gives a height dispersion with photon energy opposite to what is observed.

  10. X-ray Source Heights in a Solar Flare: Thick-target versus Thermal Conduction Front Heating

    CERN Document Server

    Reep, Jeffrey W; Holman, Gordon D

    2015-01-01

    Observations of solar flares with RHESSI have shown X-ray sources traveling along flaring loops, from the corona down to the chromosphere and back up. The 28 November 2002 C1.1 flare, first observed with RHESSI by Sui et al. 2006 and quantitatively analyzed by O'Flannagain et al. 2013, very clearly shows this behavior. By employing numerical experiments, we use these observations of X-ray source height motions as a constraint to distinguish between heating due to a non-thermal electron beam and in situ energy deposition in the corona. We find that both heating scenarios can reproduce the observed light curves, but our results favor non-thermal heating. In situ heating is inconsistent with the observed X-ray source morphology and always gives a height dispersion with photon energy opposite to what is observed.

  11. A rotational and axial motion system load frame insert for in situ high energy x-ray studies

    Energy Technology Data Exchange (ETDEWEB)

    Shade, Paul A., E-mail: paul.shade.1@us.af.mil; Schuren, Jay C.; Turner, Todd J. [Materials and Manufacturing Directorate, Air Force Research Laboratory, Wright-Patterson AFB, Ohio 45433 (United States); Blank, Basil [PulseRay, Beaver Dams, New York 14812 (United States); Kenesei, Peter; Goetze, Kurt; Lienert, Ulrich; Almer, Jonathan [Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Suter, Robert M. [Carnegie Mellon University, Pittsburgh, Pennsylvania 15213 (United States); Bernier, Joel V.; Li, Shiu Fai [Engineering Directorate, Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Lind, Jonathan [Carnegie Mellon University, Pittsburgh, Pennsylvania 15213 (United States); Engineering Directorate, Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)

    2015-09-15

    High energy x-ray characterization methods hold great potential for gaining insight into the behavior of materials and providing comparison datasets for the validation and development of mesoscale modeling tools. A suite of techniques have been developed by the x-ray community for characterizing the 3D structure and micromechanical state of polycrystalline materials; however, combining these techniques with in situ mechanical testing under well characterized and controlled boundary conditions has been challenging due to experimental design requirements, which demand new high-precision hardware as well as access to high-energy x-ray beamlines. We describe the design and performance of a load frame insert with a rotational and axial motion system that has been developed to meet these requirements. An example dataset from a deforming titanium alloy demonstrates the new capability.

  12. Multiple station beamline at an undulator x-ray source

    DEFF Research Database (Denmark)

    Als-Nielsen, J.; Freund, A.K.; Grübel, G.

    1994-01-01

    -ray transparent monochromator crystals. Diamond in particular is an attractive monochromator as it is rather X-ray transparent and can be fabricated to a high degree of crystal perfection. Moreover, it has a very high heat conductivity and a rather small thermal expansion so the beam X-ray heat load problem...

  13. Imaging of drug loading distributions in individual microspheres of calcium silicate hydrate--an X-ray spectromicroscopy study.

    Science.gov (United States)

    Guo, Xiaoxuan; Wang, Zhiqiang; Wu, Jin; Wang, Jian; Zhu, Ying-Jie; Sham, Tsun-Kong

    2015-04-21

    Imaging is one of the most direct and ideal ways to track drug loading distributions in drug carriers on the molecular level, which will facilitate the optimization of drug carriers and drug loading capacities. Herein, we report the mapping of an individual mesoporous calcium silicate hydrate (CSH) microsphere before and after the loading of ibuprofen (IBU) and the interactions between drug carriers and drug molecules simultaneously by scanning transmission X-ray microscopy (STXM). Nanoscaled X-ray absorption near edge structure (XANES) spectroscopy clearly indicates that IBU is bonded to calcium and silicate sites via carboxylic acid groups. More importantly, STXM has been successfully used to determine the absolute thickness of IBU, revealing its distribution in the CSH microsphere.

  14. X-ray fluorescence computed tomography (XFCT) imaging of gold nanoparticle-loaded objects using 110 kVp x-rays

    Energy Technology Data Exchange (ETDEWEB)

    Cheong, Seong-Kyun; Jones, Bernard L; K Siddiqi, Arsalan; Liu, Fang; Manohar, Nivedh; Cho, Sang Hyun [Nuclear and Radiological Engineering and Medical Physics Programs, Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA 30332 (United States)], E-mail: scho@gatech.edu

    2010-02-07

    A conventional x-ray fluorescence computed tomography (XFCT) technique requires monochromatic synchrotron x-rays to simultaneously determine the spatial distribution and concentration of various elements such as metals in a sample. However, the synchrotron-based XFCT technique appears to be unsuitable for in vivo imaging under a typical laboratory setting. In this study we demonstrated, for the first time to our knowledge, the possibility of performing XFCT imaging of a small animal-sized object containing gold nanoparticles (GNPs) at relatively low concentrations using polychromatic diagnostic energy range x-rays. Specifically, we created a phantom made of polymethyl methacrylate plastic containing two cylindrical columns filled with saline solution at 1 and 2 wt% GNPs, respectively, mimicking tumors/organs within a small animal. XFCT scanning of the phantom was then performed using microfocus 110 kVp x-ray beam and cadmium telluride (CdTe) x-ray detector under a pencil beam geometry after proper filtering of the x-ray beam and collimation of the detector. The reconstructed images clearly identified the locations of the two GNP-filled columns with different contrast levels directly proportional to gold concentration levels. On the other hand, the current pencil-beam implementation of XFCT is not yet practical for routine in vivo imaging tasks with GNPs, especially in terms of scanning time. Nevertheless, with the use of multiple detectors and a limited number of projections, it may still be used to image some objects smaller than the current phantom size. The current investigation suggests several modification strategies of the current XFCT setup, such as the adoption of the quasi-monochromatic cone/fan x-ray beam and XFCT-specific spatial filters or pinhole detector collimators, in order to establish the ultimate feasibility of a bench-top XFCT system for GNP-based preclinical molecular imaging applications.

  15. X-ray fluorescence computed tomography (XFCT) imaging of gold nanoparticle-loaded objects using 110 kVp x-rays.

    Science.gov (United States)

    Cheong, Seong-Kyun; Jones, Bernard L; Siddiqi, Arsalan K; Liu, Fang; Manohar, Nivedh; Cho, Sang Hyun

    2010-02-07

    A conventional x-ray fluorescence computed tomography (XFCT) technique requires monochromatic synchrotron x-rays to simultaneously determine the spatial distribution and concentration of various elements such as metals in a sample. However, the synchrotron-based XFCT technique appears to be unsuitable for in vivo imaging under a typical laboratory setting. In this study we demonstrated, for the first time to our knowledge, the possibility of performing XFCT imaging of a small animal-sized object containing gold nanoparticles (GNPs) at relatively low concentrations using polychromatic diagnostic energy range x-rays. Specifically, we created a phantom made of polymethyl methacrylate plastic containing two cylindrical columns filled with saline solution at 1 and 2 wt% GNPs, respectively, mimicking tumors/organs within a small animal. XFCT scanning of the phantom was then performed using microfocus 110 kVp x-ray beam and cadmium telluride (CdTe) x-ray detector under a pencil beam geometry after proper filtering of the x-ray beam and collimation of the detector. The reconstructed images clearly identified the locations of the two GNP-filled columns with different contrast levels directly proportional to gold concentration levels. On the other hand, the current pencil-beam implementation of XFCT is not yet practical for routine in vivo imaging tasks with GNPs, especially in terms of scanning time. Nevertheless, with the use of multiple detectors and a limited number of projections, it may still be used to image some objects smaller than the current phantom size. The current investigation suggests several modification strategies of the current XFCT setup, such as the adoption of the quasi-monochromatic cone/fan x-ray beam and XFCT-specific spatial filters or pinhole detector collimators, in order to establish the ultimate feasibility of a bench-top XFCT system for GNP-based preclinical molecular imaging applications.

  16. Design and fabrication of highly heat-resistant Mo/Si multilayer soft X-ray mirrors with interleaved barrier layers.

    Science.gov (United States)

    Takenaka, H; Ito, H; Haga, T; Kawamura, T

    1998-05-01

    Introducing interleaved carbon barrier layers improves the heat-resistance of Mo/Si multilayers. The soft X-ray reflectivities of the multilayers were calculated, and the effects of heating on both the reflectivities and layer structures of Mo/Si multilayers with and without barrier layers were investigated using X-ray diffraction and transmission electron microscopy. The results show that, for applications using intense soft X-ray beams, Mo/Si multilayers with interleaved carbon barrier layers are better mirrors than Mo/Si multilayers because they have much better heat resistance and almost the same soft X-ray reflectivity as the Mo/Si multilayers.

  17. Investigation of Deuterium Loaded Materials Subject to X-Ray Exposure

    Science.gov (United States)

    Benyo, Theresa L.; Steinetz, Bruce M.; Hendricks, Robert C.; Martin, Richard E.; Forsley, Lawrence P.; Daniels, Christopher C.; Chait, Arnon; Pines, Vladimir; Pines, Marianna; Penney, Nicholas; Kamm, Tracy R.; Becks, Michael D.

    2017-01-01

    Results are presented from an exploratory study involving x-ray irradiation of select deuterated materials. Titanium deuteride plus deuterated polyethylene, deuterated polyethylene alone, and for control, hydrogen-based polyethylene samples and nondeuterated titanium samples were exposed to x-ray irradiation. These samples were exposed to various energy levels from 65 to 280 kV with prescribed electron flux from 500 to 9000 µA impinging on a tungsten braking target, with total exposure times ranging from 55 to 280 min. Gamma activity was measured using a high-purity germanium (HPGe) detector, and for all samples no gamma activity above background was detected. Alpha and beta activities were measured using a gas proportional counter, and for select samples beta activity was measured with a liquid scintillator spectrometer. The majority of the deuterated materials subjected to the microfocus x-ray irradiation exhibited postexposure beta activity above background and several showed short-lived alpha activity. The HPE and nondeuterated titanium control samples exposed to the x-ray irradiation showed no postexposure alpha or beta activities above background. Several of the samples (SL10A, SL16, SL17A) showed beta activity above background with a greater than 4s confidence level, months after exposure. Portions of SL10A, SL16, and SL17A samples were also scanned using a beta scintillator and found to have beta activity in the tritium energy band, continuing without noticeable decay for over 12 months. Beta scintillation investigation of as-received materials (before x-ray exposure) showed no beta activity in the tritium energy band, indicating the beta emitters were not in the starting materials.

  18. X-ray and Rotational Luminosity Correlation and Magnetic Heating of the Radio Pulsars

    CERN Document Server

    Shibata, S; Yatsu, Y; Enoto, T; Bamba, A

    2016-01-01

    Previous works have suggested a correlation between the X-ray luminosity Lx and the rotational luminosity Lrot of the radio pulsars.However, none of the obtained regression lines are statistically acceptable due to large scatters. We construct a statistical model which has an intrinsic Lx-Lrot relation and reproduces the observed Lx distribution about it by using a Monte Carlo simulator, which takes into account the effects obscuring the intrinsic relation,i.e., the anisotropy of radiation, additional heating, uncertainty in distance and detection limit of the instruments. From the ATNF pulsar catalog we collect 57 `ordinary radio pulsars' with significant detection and 42 with upper limits.The sample does not include the high-magnetic field pulsars (>10^{13} G), which are separately analyzed. We obtain a statistically acceptable relation Lx (0.5 - 10 keV)= 10^{31.69} (Lrot / L_0)^{c_1} with c_1 = 1.03 \\pm 0.27 and L_0 =10^{35.38}. The distribution about the obtained Lx-Lrot relation is reproduced well by the...

  19. Infrared Line Emission from Molecular Gas Heated by X-Rays and Energetic Electrons

    Science.gov (United States)

    Maloney, Philip R.

    1997-01-01

    "I propose to carry out a detailed study using infrared observations (and in some cases, optical and ultraviolet observations) of dense interstellar gas exposed to intense fluxes of X-rays and/or energetic electrons. This is undoubtedly the dominant source of line emission for clouds exposed to X-rays from active galactic nuclei, supernova shocks, or embedded X-ray sources (e.g., X-ray binaries), or to high-temperature or relativistic electrons in galaxy clusters, near powerful radio sources, or supernova remnants. Detailed physical and chemical models of such clouds will be used to analyze infrared observations of the Great Annihilator X-ray source in the Galactic Center, cD galaxies in massive cooling flows, and the nuclei of Seyfert galaxies which will be obtained with the Infrared Space Observatory (ISO), UV and optical observations of the Crab Nebula obtained with the Hubble Space Telescope, and ground-based near-infrared observations of Seyfert nuclei. Results from this work will also be of great relevance to observations obtained with the Submillimeter Wave Astronomical Satellite (SWAS). In the first year of funding of this proposal, my chief collaborators (D.J. Hollenbach and A.G.G.M. Tielens, both of NASA Ames Research Center) and I concentrated on completing our models of the physical conditions in, and the resulting line emission from, dense gas irradiated by X-rays. As noted in the original proposal, some important physical processes were not yet thoroughly incorporated into our models at the time of submission. We completed our modeling of the physical conditions and line emission for essentially the entire range of parameter space (five orders of magnitude in X-ray flux to gas density ratio) occupied by typical dense interstellar clouds in which the gas is mostly neutral and X-rays are important for the ionization, chemistry, and thermal balance.

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

    CERN Document Server

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

    2014-01-01

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

  1. Application of X-ray phase-contrast tomography in quantative studies of heat induced structural changes in meat

    DEFF Research Database (Denmark)

    Miklos, R.; Nielsen, M. S.; Einarsdottir, Hildur;

    2013-01-01

    X-ray computed tomography is increasingly used in the studies of food structure. This paper describes the perspectives of use of phase contrast computed tomography in studies of heat induced structural changes in meat. From the data it was possible to obtain reconstructed images of the sample str...... structure for visualization and qualitative studies of the sample structure. Further data segmentation allowed structural changes to be quantified.......X-ray computed tomography is increasingly used in the studies of food structure. This paper describes the perspectives of use of phase contrast computed tomography in studies of heat induced structural changes in meat. From the data it was possible to obtain reconstructed images of the sample...

  2. Heating the Primordial Soup: X-raying the Circumstellar Disk of T Cha

    Science.gov (United States)

    Principe, David; Huenemoerder, D.; Kastner, J. H.; Bessell, M. S.; Sacco, G.

    2014-01-01

    The classical T Tauri Star (cTTS) T Chamaeleontis (T Cha) presents a unique opportunity to probe pre-main sequence star-disk interactions and late-stage circumstellar disk evolution. T Cha is the only known example of a nearly edge-on, actively accreting star/disk system within ~110 pc, and furthermore may be orbited by a low-mass companion or massive planet that has cleared an inner hole in its disk. The star is characterized by strong variability in the optical 3 magnitudes in the V band) as well as large and variable extinction (AV in the range of 1-5). Like most cTTS, T Cha is also a luminous X-ray source. We present preliminary results of two observations (totaling 150 ks) of T Cha with Chandra’s HETGS. Our motivations are to (a) determine the intrinsic X-ray spectrum of T Cha, so as to establish whether its X-ray emission can be attributed to accretion shocks, coronal emission, or a combination; (b) investigate whether its X-ray flux exhibits modulation that may be related to the stellar rotational period 3.3 days); and (c) take advantage of the nearly-edge-on disk viewing geometry to model the spectrum of X-rays absorbed by the gaseous disk orbiting T Cha. These results will serve as much-needed input to models of magnetospheric accretion and irradiated, planet-forming disks. This research is supported via award number GO3-14022X to RIT issued by the Chandra X-ray Observatory Center, which is operated by the Smithsonian Astrophysical Observatory for and on behalf of NASA under contract NAS803060. Additional support is provided by National Science Foundation grant AST-1108950 to RIT.

  3. Novel X-ray phase-contrast tomography method for quantitative studies of heat induced structural changes in meat

    DEFF Research Database (Denmark)

    Miklos, Rikke; Nielsen, Mikkel Schou; Einarsdottir, Hildur;

    2014-01-01

    The objective of this study was to evaluate the use of X-ray phase-contrast tomography combined with 3D image segmentation to investigate the heat induced structural changes in meat. The measurements were performed at the Swiss synchrotron radiation light source using a grating interferometric se...... in a qualitative and quantitative manner without prior sample preparation as isolation of single muscle components, calibration or histology....

  4. Diagnosing Direct-Drive, Shock-Heated, and Compressed Plastic Planar Foils with Noncollective Spectrally Resolved X-Ray Scattering

    Energy Technology Data Exchange (ETDEWEB)

    Sawada, H.; Regan, S.P.; Meyerhofer, D.D.; Igumenshchev, I.V.; Goncharov, V.N.; Boehly, T.R.; Epstein, R.; Sangster, T.C.; Smalyuk, V.A.; Yaakobi, B.; Gregori, G.; Glenzer, S.H.; Landen, O.L.

    2007-12-14

    The electron temperature (Te) and average ionization (Z) of nearly Fermi-degenerate, direct-drive, shock-heated, and compressed plastic planar foils were investigated using noncollective spectrally resolved x-ray scattering on the OMEGA Laser System. Plastic (CH) and Br-doped CH foils were driven with six beams, having an overlapped intensity of ~1 × 10^14 W/cm^2 and generating ~15-Mbar pressure in the foil.

  5. Molecular-dynamics approach for studying the nonequilibrium behavior of x-ray-heated solid-density matter

    Science.gov (United States)

    Abdullah, Malik Muhammad; Anurag, Jurek, Zoltan; Son, Sang-Kil; Santra, Robin

    2017-08-01

    When matter is exposed to a high-intensity x-ray free-electron-laser pulse, the x rays excite inner-shell electrons leading to the ionization of the electrons through various atomic processes and creating high-energy-density plasma, i.e., warm or hot dense matter. The resulting system consists of atoms in various electronic configurations, thermalizing on subpicosecond to picosecond timescales after photoexcitation. We present a simulation study of x-ray-heated solid-density matter. For this we use XMDYN, a Monte Carlo molecular-dynamics-based code with periodic boundary conditions, which allows one to investigate nonequilibrium dynamics. XMDYN is capable of treating systems containing light and heavy atomic species with full electronic configuration space and three-dimensional spatial inhomogeneity. For the validation of our approach we compare for a model system the electron temperatures and the ion charge-state distribution from XMDYN to results for the thermalized system based on the average-atom model implemented in XATOM, an ab initio x-ray atomic physics toolkit extended to include a plasma environment. Further, we also compare the average charge evolution of diamond with the predictions of a Boltzmann continuum approach. We demonstrate that XMDYN results are in good quantitative agreement with the above-mentioned approaches, suggesting that the current implementation of XMDYN is a viable approach to simulate the dynamics of x-ray-driven nonequilibrium dynamics in solids. To illustrate the potential of XMDYN for treating complex systems, we present calculations on the triiodo benzene derivative 5-amino-2,4,6-triiodoisophthalic acid (I3C), a compound of relevance of biomolecular imaging, consisting of heavy and light atomic species.

  6. Continuous heating of a giant X-ray flare on Algol

    CERN Document Server

    Schmitt, J H M M

    1999-01-01

    Giant flares can release large amounts of energy within a few days: X-ray emission alone can be up to ten percent of the star's bolometric luminosity. These flares exceed the luminosities of the largest solar flares by many orders of magnitude, which suggests that the underlying physical mechanisms supplying the energy are different from those on the Sun. Magnetic coupling between the components in a binary system or between a young star and an accretion disk has been proposed as a prerequisite for giant flares. Here we report X-ray observations of a giant flare on Algol B, a giant star in an eclipsing binary system. We observed a total X-ray eclipse of the flare, which demonstrates that the plasma was confined to Algol B, and reached a maximum height of 0.6 stellar radii above its surface. The flare occurred around the south pole of Algol B, and energy must have been released continously throughout its life. We conclude that a specific extrastellar environment is not required for the presence of a flare, and...

  7. Testing for Shock-Heated X-Ray Gas around Compact Steep Spectrum Radio Galaxies

    Science.gov (United States)

    Noel-Storr, Jacob; O'Dea, Christopher; Worrall, Diana M.; Clarke, Tracy E.; Tremblay, Grant; Baum, Stefi; Christiansen, Kevin; Mullarkey, Christopher; Mittal, Rupal

    2017-01-01

    We present Chandra and XMM-Newton X-ray, VLA radio, and optical observations of two CSS radio galaxies. B3 1445+410 is a low excitation emission line galaxy with possibly a hybrid FRI/II (or Fat Double) radio morphology. The Chandra observations are point-like and well fit with a power-law consistent with emission from a Doppler boosted core. PKS B1017-325 is a galaxy with a bent double radio morphology. The XMM-Newton observations are consistent with an ISM with a contribution from hot shocked gas. We compile selected radio and X-ray properties of the nine CSS radio galaxies with X-ray detections so far. We find that 1/3 show evidence for hot shocked gas. We note that the counts in the sources are low and the properties of the 3 sources with evidence for hot shocked gas are typical of the other CSS radio galaxies. We suggest that hot shocked gas may be typical of CSS radio galaxies due to their propagation through their host galaxies.

  8. Continuous heating of a giant X-ray flare on Algol

    Science.gov (United States)

    Schmitt, J. H. M. M.; Favata, F.

    1999-09-01

    Giant stellar flares can release large amounts of energy within a few days: X-ray emission alone can be up to ten per cent of the star's bolometric luminosity. These flares exceed the luminosities of the largest solar flares by many orders of magnitude, which suggests that the underlying physical mechanisms supplying the energy are different from those on the Sun. Magnetic coupling between the components in a binary system or between a young star and an accretion disk has been proposed as a prerequisite for giant flares. Here we report X-ray observations of a giant flare on Algol B, a giant star in an eclipsing binary system. We observed a total X-ray eclipse of the flare, which demonstrates that the plasma was confined to Algol B, and reached a maximum height of 0.6 stellar radii above its surface. The flare occurred around the south pole of Algol B, and energy must have been released continuously throughout its life. We conclude that a specific extrastellar environment is not required for the presence of a flare, and that the processes at work are therefore similar to those on the Sun.

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

    Science.gov (United States)

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

    2015-01-01

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

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

    Science.gov (United States)

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

    2017-02-01

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

  11. Soft x-ray intensity profile measurements of electron cyclotron heated plasmas using semiconductor detector arrays in GAMMA 10 tandem mirror.

    Science.gov (United States)

    Minami, R; Imai, T; Kariya, T; Numakura, T; Eguchi, T; Kawarasaki, R; Nakazawa, K; Kato, T; Sato, F; Nanzai, H; Uehara, M; Endo, Y; Ichimura, M

    2014-11-01

    Temporally and spatially resolved soft x-ray analyses of electron cyclotron heated plasmas are carried out by using semiconductor detector arrays in the GAMMA 10 tandem mirror. The detector array has 16-channel for the measurements of plasma x-ray profiles so as to make x-ray tomographic reconstructions. The characteristics of the detector array make it possible to obtain spatially resolved plasma electron temperatures down to a few tens eV and investigate various magnetohydrodynamic activities. High power electron cyclotron heating experiment for the central-cell region in GAMMA 10 has been started in order to reduce the electron drag by increasing the electron temperature.

  12. Continuous heating of a giant X-ray flare on Algol

    OpenAIRE

    Schmitt, J. H. M. M.; Favata, F.

    1999-01-01

    Giant flares can release large amounts of energy within a few days: X-ray emission alone can be up to ten percent of the star's bolometric luminosity. These flares exceed the luminosities of the largest solar flares by many orders of magnitude, which suggests that the underlying physical mechanisms supplying the energy are different from those on the Sun. Magnetic coupling between the components in a binary system or between a young star and an accretion disk has been proposed as a prerequisi...

  13. Combined resistive and laser heating technique for in situ radial X-ray diffraction in the diamond anvil cell at high pressure and temperature.

    Science.gov (United States)

    Miyagi, Lowell; Kanitpanyacharoen, Waruntorn; Raju, Selva Vennila; Kaercher, Pamela; Knight, Jason; MacDowell, Alastair; Wenk, Hans-Rudolf; Williams, Quentin; Alarcon, Eloisa Zepeda

    2013-02-01

    To extend the range of high-temperature, high-pressure studies within the diamond anvil cell, a Liermann-type diamond anvil cell with radial diffraction geometry (rDAC) was redesigned and developed for synchrotron X-ray diffraction experiments at beamline 12.2.2 of the Advanced Light Source. The rDAC, equipped with graphite heating arrays, allows simultaneous resistive and laser heating while the material is subjected to high pressure. The goals are both to extend the temperature range of external (resistive) heating and to produce environments with lower temperature gradients in a simultaneously resistive- and laser-heated rDAC. Three different geomaterials were used as pilot samples to calibrate and optimize conditions for combined resistive and laser heating. For example, in Run#1, FeO was loaded in a boron-mica gasket and compressed to 11 GPa then gradually resistively heated to 1007 K (1073 K at the diamond side). The laser heating was further applied to FeO to raise temperature to 2273 K. In Run#2, Fe-Ni alloy was compressed to 18 GPa and resistively heated to 1785 K (1973 K at the diamond side). The combined resistive and laser heating was successfully performed again on (Mg0.9Fe0.1)O in Run#3. In this instance, the sample was loaded in a boron-kapton gasket, compressed to 29 GPa, resistive-heated up to 1007 K (1073 K at the diamond side), and further simultaneously laser-heated to achieve a temperature in excess of 2273 K at the sample position. Diffraction patterns obtained from the experiments were deconvoluted using the Rietveld method and quantified for lattice preferred orientation of each material under extreme conditions and during phase transformation.

  14. Combined resistive and laser heating technique for in situ radial X-ray diffraction in the diamond anvil cell at high pressure and temperature

    Energy Technology Data Exchange (ETDEWEB)

    Miyagi, Lowell [Department of Geology and Geophysics, University of Utah, Salt Lake City, Utah 84112 (United States); Department of Earth Sciences, Montana State University, Bozeman, Montana 59717 (United States); Kanitpanyacharoen, Waruntorn; Kaercher, Pamela; Wenk, Hans-Rudolf; Alarcon, Eloisa Zepeda [Department of Earth and Planetary Science, University of California, Berkeley, California 94720 (United States); Raju, Selva Vennila [Advanced Light Source, Lawrence Berkeley Laboratory, Berkeley, California 94720 (United States); HiPSEC, Department of Physics, University of Nevada, Las Vegas, Nevada 89154 (United States); Knight, Jason; MacDowell, Alastair [Advanced Light Source, Lawrence Berkeley Laboratory, Berkeley, California 94720 (United States); Williams, Quentin [Department of Earth and Planetary Science, University of California, Santa Cruz, California 95064 (United States)

    2013-02-15

    To extend the range of high-temperature, high-pressure studies within the diamond anvil cell, a Liermann-type diamond anvil cell with radial diffraction geometry (rDAC) was redesigned and developed for synchrotron X-ray diffraction experiments at beamline 12.2.2 of the Advanced Light Source. The rDAC, equipped with graphite heating arrays, allows simultaneous resistive and laser heating while the material is subjected to high pressure. The goals are both to extend the temperature range of external (resistive) heating and to produce environments with lower temperature gradients in a simultaneously resistive- and laser-heated rDAC. Three different geomaterials were used as pilot samples to calibrate and optimize conditions for combined resistive and laser heating. For example, in Run1, FeO was loaded in a boron-mica gasket and compressed to 11 GPa then gradually resistively heated to 1007 K (1073 K at the diamond side). The laser heating was further applied to FeO to raise temperature to 2273 K. In Run2, Fe-Ni alloy was compressed to 18 GPa and resistively heated to 1785 K (1973 K at the diamond side). The combined resistive and laser heating was successfully performed again on (Mg{sub 0.9}Fe{sub 0.1})O in Run3. In this instance, the sample was loaded in a boron-kapton gasket, compressed to 29 GPa, resistive-heated up to 1007 K (1073 K at the diamond side), and further simultaneously laser-heated to achieve a temperature in excess of 2273 K at the sample position. Diffraction patterns obtained from the experiments were deconvoluted using the Rietveld method and quantified for lattice preferred orientation of each material under extreme conditions and during phase transformation.

  15. Mechanical stability of individual austenite grains in TRIP steel studied by synchrotron X-ray diffraction during tensile loading

    Energy Technology Data Exchange (ETDEWEB)

    Blondé, R. [Fundamental Aspects of Materials and Energy, Faculty of Applied Sciences, Delft University of Technology, Mekelweg 15, 2629 JB Delft (Netherlands); Materials Innovation Institute, Mekelweg 2, 2628 CD Delft (Netherlands); Jimenez-Melero, E. [Dalton Cumbrian Facility, The University of Manchester, Westlakes Science and Technology Park, Moor Row, Cumbria, CA24 3HA (United Kingdom); Zhao, L. [Materials Innovation Institute, Mekelweg 2, 2628 CD Delft (Netherlands); Department of Materials Science and Engineering, Delft University of Technology, Mekelweg 2, 2628 CD Delft (Netherlands); Wright, J.P. [European Synchrotron Radiation Facility, 6 Rue Jules Horowitz, BP 220, 38043 Grenoble Cedex (France); Brück, E. [Fundamental Aspects of Materials and Energy, Faculty of Applied Sciences, Delft University of Technology, Mekelweg 15, 2629 JB Delft (Netherlands); Zwaag, S. van der [Novel Aerospace Materials Group, Faculty of Aerospace Engineering, Delft University of Technology, Kluyverweg 1, 2629 HS, Delft (Netherlands); Dijk, N.H. van, E-mail: N.H.vanDijk@tudelft.nl [Fundamental Aspects of Materials and Energy, Faculty of Applied Sciences, Delft University of Technology, Mekelweg 15, 2629 JB Delft (Netherlands)

    2014-11-17

    The stability of individual metastable austenite grains in low-alloyed TRIP steels has been studied during tensile loading using high-energy X-ray diffraction. The carbon concentration, grain volume and grain orientation with respect to the loading direction was monitored for a large number of individual grains in the bulk microstructure. Most austenite grains transform into martensite in a single transformation step once a critical load is reached. The orientation-dependent stability of austenite grains was found to depend on their Schmid factor with respect to the loading direction. Under the applied tensile stress the average Schmid factor decreased from an initial value of 0.44 to 0.41 at 243 MPa. The present study reveals the complex interplay of microstructural parameters on the mechanical stability of individual austenite grains, where the largest grains with the lowest carbon content tend to transform first. Under the applied tensile stress the average carbon concentration of the austenite grains increased from an initial value of 0.90 to 1.00 wt% C at 243 MPa, while the average grain volume of the austenite grains decreased from an initial value of 19 to 15 µm{sup 3} at 243 MPa.

  16. Ultrafast x-ray diffraction thermometry measures the influence of spin excitations on the heat transport through nanolayers

    Science.gov (United States)

    Koc, A.; Reinhardt, M.; von Reppert, A.; Rössle, M.; Leitenberger, W.; Dumesnil, K.; Gaal, P.; Zamponi, F.; Bargheer, M.

    2017-07-01

    We investigate the heat transport through a rare earth multilayer system composed of yttrium (Y), dysprosium (Dy), and niobium (Nb) by ultrafast x-ray diffraction. This is an example of a complex heat flow problem on the nanoscale, where several different quasiparticles carry the heat and conserve a nonequilibrium for more than 10 ns. The Bragg peak positions of each layer represent layer-specific thermometers that measure the energy flow through the sample after excitation of the Y top layer with fs-laser pulses. In an experiment-based analytic solution to the nonequilibrium heat transport problem, we derive the individual contributions of the spins and the coupled electron-lattice system to the heat conduction. The full characterization of the spatiotemporal energy flow at different starting temperatures reveals that the spin excitations of antiferromagnetic Dy speed up the heat transport into the Dy layer at low temperatures, whereas the heat transport through this layer and further into the Y and Nb layers underneath is slowed down. The experimental findings are compared to the solution of the heat equation using macroscopic temperature-dependent material parameters without separation of spin and phonon contributions to the heat. We explain why the simulated energy density matches our experiment-based derivation of the heat transport, although the simulated thermoelastic strain in this simulation is not even in qualitative agreement.

  17. A simple external resistance heating diamond anvil cell and its application for synchrotron radiation x-ray diffraction.

    Science.gov (United States)

    Fan, Dawei; Zhou, Wenge; Wei, Shuyi; Liu, Yonggang; Ma, Maining; Xie, Hongsen

    2010-05-01

    A simple external heating assemblage allowing diamond anvil cell experiments at pressures up to 34 GPa and temperatures up to 653 K was constructed. This cell can be connected to the synchrotron radiation conveniently. The design and construction of this cell are fully described, as well as its applications for x-ray diffraction. Heating is carried out by using an external-heating system, which is made of NiCr resistance wire, and the temperature was measured by a NiCr-NiSi or PtRh-Pt thermocouple. We showed the performance of the new system by introducing the phase transition study of cinnabar (alpha-HgS) and thermal equation of state study of almandine at high pressure and temperature with this cell.

  18. Optics for coherent X-ray applications

    Energy Technology Data Exchange (ETDEWEB)

    Yabashi, Makina, E-mail: yabashi@spring8.or.jp [RIKEN SPring-8 Center, Kouto 1-1-1, Sayo, Hyogo 679-5148 (Japan); Tono, Kensuke [Japan Synchrotron Radiation Research Institute (JASRI), Kouto 1-1-1, Sayo, Hyogo 679-5198 (Japan); Mimura, Hidekazu [The University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-8656 (Japan); Matsuyama, Satoshi; Yamauchi, Kazuto [Osaka University, 2-1 Yamada-oka, Suita, Osaka 565-0871 (Japan); Tanaka, Takashi; Tanaka, Hitoshi; Tamasaku, Kenji [RIKEN SPring-8 Center, Kouto 1-1-1, Sayo, Hyogo 679-5148 (Japan); Ohashi, Haruhiko; Goto, Shunji [Japan Synchrotron Radiation Research Institute (JASRI), Kouto 1-1-1, Sayo, Hyogo 679-5198 (Japan); Ishikawa, Tetsuya [RIKEN SPring-8 Center, Kouto 1-1-1, Sayo, Hyogo 679-5148 (Japan)

    2014-08-27

    Developments of optics for coherent X-ray applications and their role in diffraction-limited storage rings are described. Developments of X-ray optics for full utilization of diffraction-limited storage rings (DLSRs) are presented. The expected performance of DLSRs is introduced using the design parameters of SPring-8 II. To develop optical elements applicable to manipulation of coherent X-rays, advanced technologies on precise processing and metrology were invented. With propagation-based coherent X-rays at the 1 km beamline of SPring-8, a beryllium window fabricated with the physical-vapour-deposition method was found to have ideal speckle-free properties. The elastic emission machining method was utilized for developing reflective mirrors without distortion of the wavefronts. The method was further applied to production of diffraction-limited focusing mirrors generating the smallest spot size in the sub-10 nm regime. To enable production of ultra-intense nanobeams at DLSRs, a low-vibration cooling system for a high-heat-load monochromator and advanced diagnostic systems to characterize X-ray beam properties precisely were developed. Finally, new experimental schemes for combinative nano-analysis and spectroscopy realised with novel X-ray optics are discussed.

  19. Measurements of the K -Shell Opacity of a Solid-Density Magnesium Plasma Heated by an X-Ray Free-Electron Laser

    Science.gov (United States)

    Preston, T. R.; Vinko, S. M.; Ciricosta, O.; Hollebon, P.; Chung, H.-K.; Dakovski, G. L.; Krzywinski, J.; Minitti, M.; Burian, T.; Chalupský, J.; Hájková, V.; Juha, L.; Vozda, V.; Zastrau, U.; Lee, R. W.; Wark, J. S.

    2017-08-01

    We present measurements of the spectrally resolved x rays emitted from solid-density magnesium targets of varying sub-μ m thicknesses isochorically heated by an x-ray laser. The data exhibit a largely thickness-independent source function, allowing the extraction of a measure of the opacity to K -shell x rays within well-defined regimes of electron density and temperature, extremely close to local thermodynamic equilibrium conditions. The deduced opacities at the peak of the K α transitions of the ions are consistent with those predicted by detailed atomic-kinetics calculations.

  20. Competitive molecular interaction among paeonol-loaded liposomes: differential scanning calorimetry and synchrotron X-ray diffraction studies.

    Science.gov (United States)

    Wu, Rui-guang; Dai, Jun-dong; Wu, Fu-gen; Zhang, Xiao-hua; Li, Wei-heng; Wang, Yu-rong

    2012-11-15

    Thermotropic phase behavior of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) liposomes containing 5 mol% cholesterol, or 5 mol% stigmasterol, or 5 mol% paeonol have been investigated by differential scanning calorimetry (DSC) and synchrotron X-ray diffraction (XRD) techniques, to investigate the competitive molecular interaction among paeonol-loaded liposomes. The results show that both sterol and paeonol can incorporate into hydrophobic region and interact with acyl chains of DPPC. Both 5 mol% sterols and 5 mol% paeonol can promote the formation of rippled gel phase of DPPC liposomes at room temperature. 5 mol% paeonol can induce the occurrence of phase separation in DPPC liposomes, but 5 mol% cholesterol or 5 mol% stigmasterol cannot induce this phenomenon. Both the repeat distance and the correlation length of paeonol-poor domain are larger than those of coexisted paeonol-rich domain. Both calorimetric data and SAXS patterns show that sterols have more favorable, stabilizing interactions with DPPC than paeonol, implying that high concentrations of sterols will have a negative effect on the loading of paeonol. In addition, calorimetric data show that cholesterol have a little more favorable, stabilizing interactions with DPPC than stigmasterol. The results of this study will play an important role in optimizing the formulation of paeonol-loaded liposomes. Copyright © 2012 Elsevier B.V. All rights reserved.

  1. Solar Hard X-ray Source Sizes in a Beam-Heated and Ionised Chromosphere

    CERN Document Server

    O'Flannagain, A; Gallagher, P T

    2014-01-01

    Solar flare hard X-rays (HXRs) are produced as bremsstrahlung when an accelerated population of electrons interacts with the dense chromospheric plasma. HXR observations presented by using the Ramaty High-Energy Solar Spectroscopic Imager (RHESSI) have shown that HXR source sizes are 3-6 times more extended in height than those predicted by the standard collisional thick target model (CTTM). Several possible explanations have been put forward including the multi-threaded nature of flare loops, pitch-angle scattering, and magnetic mirroring. However, the nonuniform ionisation (NUI) structure along the path of the electron beam has not been fully explored as a solution to this problem. Ionised plasma is known to be less effective at producing nonthermal bremsstrahlung HXRs when compared to neutral plasma. If the peak HXR emission was produced in a locally ionised region within the chromosphere, the intensity of emission will be preferentially reduced around this peak, resulting in a more extended source. Due to...

  2. Dynamics of a Z Pinch X Ray Source for Heating ICF Relevant Hohlraums to 120-160eV

    Energy Technology Data Exchange (ETDEWEB)

    SANFORD,THOMAS W. L.; OLSON,RICHARD E.; MOCK,RAYMOND CECIL; CHANDLER,GORDON A.; LEEPER,RAMON J.; NASH,THOMAS J.; RUGGLES,LAURENCE E.; SIMPSON,WALTER W.; STRUVE,KENNETH W.; PETERSON,D.L.; BOWERS,R.L.; MATUSKA,W.

    2000-07-10

    A z-pinch radiation source has been developed that generates 60 {+-} 20 KJ of x-rays with a peak power of 13 {+-} 4 TW through a 4-mm diameter axial aperture on the Z facility. The source has heated NIF (National Ignition Facility)-scale (6-mm diameter by 7-mm high) hohlraums to 122 {+-} 6 eV and reduced-scale (4-mm diameter by 4-mm high) hohlraums to 155 {+-} 8 eV -- providing environments suitable for indirect-drive ICF (Inertial Confinement Fusion) studies. Eulerian-RMHC (radiation-hydrodynamics code) simulations that take into account the development of the Rayleigh-Taylor instability in the r-z plane provide integrated calculations of the implosion, x-ray generation, and hohlraum heating, as well as estimates of wall motion and plasma fill within the hohlraums. Lagrangian-RMHC simulations suggest that the addition of a 6 mg/cm{sup 3} CH{sub 2} fill in the reduced-scale hohlraum decreases hohlraum inner-wall velocity by {approximately}40% with only a 3--5% decrease in peak temperature, in agreement with measurements.

  3. Volume digital image correlation to assess displacement field in compression loaded bread crumb under X-ray microtomography

    KAUST Repository

    Moussawi, Ali

    2014-10-01

    In this study, we present an original approach to assess structural changes during bread crumb compression using a mechanical testing bench coupled to 3D X-ray microtomography. X-ray images taken at different levels of compression of the bread crumb are processed using image analysis. A subset-based digital volume correlation method is used to achieve the 3D displacement field. Within the limit of the approach, deterministic search strategy is implemented for solving subset displacement in each deformed image with regards to the undeformed one. The predicted displacement field in the transverse directions shows differences that depend on local cell arrangement as confirmed by finite element analysis. The displacement component in the loading direction is affected by the magnitude of imposed displacement and shows more regular change. Large displacement levels in the compression direction are in good agreement with the imposed experimental displacement. The results presented here are promising in a sense of possible identification of local foam properties. New insights are expected to achieve better understanding of structural heterogeneities in the overall perception of the product. Industrial relevance: Texture evaluation of cereal product is an important aspect for testing consumer acceptability of new designed products. Mechanical evaluation of backed products is a systemic route for determining texture of cereal based product. From the industrial viewpoint, mechanical evaluation allows saving both time and cost compared to panel evaluation. We demonstrate that better understanding of structural changes during texture evaluation can be achieved in addition to texture evaluation. Sensing structural changes during bread crumb compression is achievable by combining novel imaging technique and processing based on image analysis. We present thus an efficient way to predict displacements during compression of freshly baked product. This method can be used in different

  4. Photosensitization of plasmid-DNA loaded with platinum nano-particles and irradiated by low energy X-rays

    Science.gov (United States)

    Porcel, E.; Kobayashi, K.; Usami, N.; Remita, H.; Le Sech, C.; Lacombe, S.

    2011-01-01

    Damage in DNA plasmids (pBR322) loaded with platinum nanoparticles (NP-Pt) DNA-NP and irradiated with monochromatic X-rays tuned to the resonant photoabsorption energy of the LIII and MIII electronic inner-shell of platinum - respectively 11556 eV and 2649 eV - and off-resonant X-rays - 11536 eV and 2639 eV- is investigated. In all the experiments, an enhancement of the single and double strand break - SSB and DSB - yields is observed when NP-Pt are present. Amplification effects are almost similar for the irradiations performed at on and off the L or M shell resonance suggesting that a non resonant mechanism is responsible for the major part of the DNA breaks enhancement.The amount of DNA breaks measured in the present work is compared to the results in similar experiments made with complexes of plasmid-DNA containing platinum molecule : chloroterpyridine platinum (PtTC). The average number of PtTC molecules in the solution is the same as in the experiments made with NP-Pt in order to study a possible difference in the radiosensitization efficiency when the high-Z atoms are clustered (NP-Pt) or dispersed in the system (PtTC). A mechanism is suggested involving photoelectrons which can efficiently ionize the platinum atoms. These results are consistent with those observed when DNA-NP complexes are irradiated by fast atomic ions. These findings suggest that any nanoparticle made of high-Z atoms might behaves as radiation enhancer whatever the ionizing radiation is electromagnetic or charged particle source.

  5. The wire array Z-pinch: an efficient x-ray source for ICF and a new ion heating mechanism

    Science.gov (United States)

    Haines, M. G.

    2008-10-01

    The Z-pinch provides an efficient x-ray source for driving a hohlraum for inertial confinement fusion. The basic physics of wire-array implosions is reviewed. It can be understood in several sequential stages. Firstly, the wires heat and form a surrounding vapour which ionizes, causing the current to transfer to this lower resistance. The J×B global force leads to ejection of this plasma towards the axis to form a precursor plasma. The wire cores continue to ablate due to the heat flux from the Joule-heated nearby plasma. The cooling of this plasma by the wire-cores leads to a low magnetic Reynolds number so that the precursor plasma carries little or no current. When gaps appear in the liquid/vapour cores the plasma temperature and Reynolds number rise and this plasma accelerates in towards the axis carrying the current. This is the main implosion, and it sweeps up earlier ablated plasma, which acts to reduce Rayleigh-Taylor growth. At stagnation, the ion kinetic energy is thermalized and equipartition heats the electrons, which then radiate in a 5 ns pulse. In some conditions the energy radiated by soft x-rays exceeds the ion kinetic energy by a factor of 3 or 4. A theory has been developed to explain this in which fine-scale, fast growing m= 0 MHD instabilities grow to saturation, viscous dissipation of which leads to ion heating, followed by equipartition. World record ion temperatures of 2-3 billion Kelvin were predicted, and measured at Sandia National Laboratory. Lastly, progress in capsule implosions and in application to inertial fusion energy is reported.

  6. The Wire Array Z-Pinch AN Efficient X-Ray Source for Icf and a New Ion Heating Mechanism

    Science.gov (United States)

    Haines, M. G.

    2009-07-01

    The Z-pinch provides an efficient x-ray source for driving a hohlraum for inertial confinement fusion. The basic physics of wire-array implosions is reviewed. It can be understood in several sequential stages. First, the wires heat and form a surrounding vapor which ionizes, causing the current to transfer to this lower resistance. The J×B global force leads to ejection of this plasma towards the axis to form a precursor plasma. The wire cores continue to ablate due to the heat flux from the Joule-heated nearby plasma. The cooling of this plasma by the wire-cores leads to a low magnetic Reynolds number so that the precursor plasma carries little or no current. When gaps appear in the liquid/vapor cores the plasma temperature and Reynolds' number rise and this plasma accelerates in towards the axis carrying the current. This is the main implosion, and it sweeps up earlier ablated plasma, which acts to reduce Rayleigh-Taylor growth. At stagnation the ion kinetic energy is thermalised and equipartition heats the electrons, which then radiate in a 5 ns pulse. In some conditions the energy radiated as soft x-rays exceeds the ion kinetic energy by a factor of 3 or 4. A theory has been developed to explain this in which fine-scale, fast growing m = 0 MHD instabilities grow to saturation, viscous dissipation of which leads to ion heating, followed by equipartition. World record ion temperatures of 2 to 3 billion Kelvin were predicted, and measured at Sandia National Laboratory. Lastly progress in capsule implosions and in application to inertial fusion energy is reported.

  7. Small-angle X-ray scattering studies of metastable intermediates of beta-lactoglobulin isolated after heat-induced aggregation

    DEFF Research Database (Denmark)

    Carrotta, R.; Arleth, L.; Pedersen, J.S.

    2003-01-01

    Small-angle x-ray scattering was used for studying intermediate species, isolated after heat-induced aggregation of the A variant of bovine P-lactoglobulin. The intermediates were separated in two fractions, the heated metastable dimer and heated metastable oligomers larger than the dimer. The pa...

  8. Analysis of micro-structure in raw and heat treated meat emulsions from multimodal X-ray microtomography

    DEFF Research Database (Denmark)

    Einarsdottir, Hildur; Nielsen, Mikkel Schou; Miklos, Rikke

    2014-01-01

    microstructural differences when either pork fat or sunflower oil was added. From the reconstructed tomograms the different constituents in the emulsions were segmented using a multivariate segmentation method. From this, a quantitative analysis was performed between the different samples, determining properties...... such as percent object volumes, porosity, average structure thickness and cooking loss. The grating-based X-ray technique andmultivariate segmentation made the analysis of the microstructure possible which further gives insight to how both heat treatment, and the use of different lipid types, affect the final...... the microstructural changes induced by heat treatment. It provides high-resolution three dimensional spatial information and in contrast to 2D imaging methods, quantitative parameters can be extracted by image analysis for the entire sample volume. Additionally, the non-destructive method allows for imaging the same...

  9. Systematic errors in digital volume correlation due to the self-heating effect of a laboratory x-ray CT scanner

    Science.gov (United States)

    Wang, B.; Pan, B.; Tao, R.; Lubineau, G.

    2017-04-01

    The use of digital volume correlation (DVC) in combination with a laboratory x-ray computed tomography (CT) for full-field internal 3D deformation measurement of opaque materials has flourished in recent years. During x-ray tomographic imaging, the heat generated by the x-ray tube changes the imaging geometry of x-ray scanner, and further introduces noticeable errors in DVC measurements. In this work, to provide practical guidance high-accuracy DVC measurement, the errors in displacements and strains measured by DVC due to the self-heating for effect of a commercially available x-ray scanner were experimentally investigated. The errors were characterized by performing simple rescan tests with different scan durations. The results indicate that the maximum strain errors associated with the self-heating of the x-ray scanner exceed 400 µε. Possible approaches for minimizing or correcting these displacement and strain errors are discussed. Finally, a series of translation and uniaxial compression tests were performed, in which strain errors were detected and then removed using pre-established artificial dilatational strain-time curve. Experimental results demonstrate the efficacy and accuracy of the proposed strain error correction approach.

  10. Systematic errors in digital volume correlation due to the self-heating effect of a laboratory x-ray CT scanner

    KAUST Repository

    Wang, B

    2017-02-15

    The use of digital volume correlation (DVC) in combination with a laboratory x-ray computed tomography (CT) for full-field internal 3D deformation measurement of opaque materials has flourished in recent years. During x-ray tomographic imaging, the heat generated by the x-ray tube changes the imaging geometry of x-ray scanner, and further introduces noticeable errors in DVC measurements. In this work, to provide practical guidance high-accuracy DVC measurement, the errors in displacements and strains measured by DVC due to the self-heating for effect of a commercially available x-ray scanner were experimentally investigated. The errors were characterized by performing simple rescan tests with different scan durations. The results indicate that the maximum strain errors associated with the self-heating of the x-ray scanner exceed 400 µε. Possible approaches for minimizing or correcting these displacement and strain errors are discussed. Finally, a series of translation and uniaxial compression tests were performed, in which strain errors were detected and then removed using pre-established artificial dilatational strain-time curve. Experimental results demonstrate the efficacy and accuracy of the proposed strain error correction approach.

  11. X-ray visible and doxorubicin-loaded beads based on inherently radiopaque poly(lactic acid)-polyurethane for chemoembolization therapy.

    Science.gov (United States)

    Sang, Lin; Luo, Dongdong; Wei, Zhiyong; Qi, Min

    2017-06-01

    The aim of current study was to develop drug-loaded polymeric beads with intrinsic X-ray visibility as embolic agents, targeting for noninvasive intraoperative location and postoperative examination during chemoembolization therapy. To endow polymer with inherent radiopacity, 4,4'-isopropylidinedi-(2,6-diiodophenol) (IBPA) was firstly synthesized and employed as a contrast agent, and then a set of radiopaque iodinated poly(lactic acid)-polyurethanes (I-PLAUs) via chain extender method were synthesized and characterized. These I-PLAU copolymers possessed sufficient radiopacity, in vitro non-cytotoxicity with human adipose-derived stem cells, and in vivo biocompatibility and degradability in rabbit model via intramuscular implantation. Doxorubicin (DOX), as a chemotherapeutic agent, was further incorporated into I-PLAU beads via a double emulsification (W/O/W) method. For drug release, two ratios of DOX-loaded I-PLAU beads exhibited calibrated size (200-550μm), porous internal structure, good X-ray visibility, evenly drug loading as well as tunable drug release. A preliminary test on in vitro tumor cell toxicity demonstrated that the DOX-loaded I-PLAU beads performed efficient anti-tumor effect. This study highlights novel X-ray visible drug-loaded I-PLAU beads used as promising embolic agents for non-invasive in situ X-ray tracking and efficient chemotherapy, which could bring opportunities to the next generation of multifunctional embolic agents. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Study of Mechanical Properties of Bone by Measuring Load Transfer via High-energy X-ray Diffraction

    Science.gov (United States)

    Singhal, Anjali

    Synchrotron high-energy X-ray scattering is used to investigate the in situ strains in hydroxyapatite (HAP) platelets and mineralized collagen fibrils in bovine cortical bone. Compressive load-unload tests at room temperature (27°C) and body temperature (37°C) show that the load transfer to the stiff nano-sized platelets from the surrounding compliant protein matrix does not vary significantly with temperature. This emphasizes that the stiffness of bone is controlled by the stiffness of the HAP phase, which remains unaffected by this change in temperature. Monotonic loading tests in compression and tension, conducted at 37°C, illustrate the spatial variation of properties within a single femur, which is correlated to the mineral content, porosity and microstructure of the samples. The average apparent modulus of HAP and fibrils (EappHAP and Eappfib, respectively), defined as the ratio of applied stress and phase strain, is obtained as 27.5 ± 6.6 and 18.5 ± 8.9 GPa, respectively, in compression. These values are significantly higher than the values of 20.0 ± 5.4 and 4.1 ± 2.6 GPa obtained for HAP and fibrils, respectively, in tension. The difference between the two types of loading is attributed to greater plastic deformation of collagen in tension, which results in greater strains in the collagen fibril, and concomitant greater load transfer to the HAP. Increasing synchrotron X-ray doses (5-3880 kGy) affect neither apparent HAP nor fibrillar modulus, up to stresses of -60 MPa (measured during in situ loading and unloading). However, the residual elastic strains in the HAP phase decrease markedly with increased irradiation, indicating damage at the HAP-collagen interface. Analysis of the X-ray diffraction peak widths shows that unit cells of HAP which are under the highest initial residual strains are most able to relax due to irradiation, resulting in a net decrease in the strain distribution (RMS strain). The constancy of apparent moduli is explained by

  13. Constraining a Model of Turbulent Coronal Heating for AU Microscopii with X-Ray, Radio, and Millimeter Observations

    CERN Document Server

    Cranmer, Steven R; MacGregor, Meredith A

    2013-01-01

    Many low-mass pre-main-sequence stars exhibit strong magnetic activity and coronal X-ray emission. Even after the primordial accretion disk has been cleared out, the star's high-energy radiation continues to affect the formation and evolution of dust, planetesimals, and large planets. Young stars with debris disks are thus ideal environments for studying the earliest stages of non-accretion-driven coronae. In this paper we simulate the corona of AU Mic, a nearby active M dwarf with an edge-on debris disk. We apply a self-consistent model of coronal loop heating that was derived from numerical simulations of solar field-line tangling and magnetohydrodynamic turbulence. We also synthesize the modeled star's X-ray luminosity and thermal radio/millimeter continuum emission. A realistic set of parameter choices for AU Mic produces simulated observations that agree with all existing measurements and upper limits. This coronal model thus represents an alternative explanation for a recently discovered ALMA central em...

  14. Hot gaseous atmospheres in galaxy groups and clusters are both heated and cooled by X-ray cavities

    CERN Document Server

    Brighenti, Fabrizio; Temi, Pasquale

    2015-01-01

    Expanding X-ray cavities observed in hot gas atmospheres of many galaxy groups and clusters generate shock waves and turbulence that are primary heating mechanisms required to avoid uninhibited radiatively cooling flows which are not observed. However, we show here that the evolution of buoyant cavities also stimulates radiative cooling of observable masses of low-temperature gas. During their early evolution, radiative cooling occurs in the wakes of buoyant cavities in two locations: in thin radial filaments parallel to the buoyant velocity and more broadly in gas compressed beneath rising cavities. Radiation from these sustained compressions removes entropy from the hot gas. Gas experiencing the largest entropy loss cools first, followed by gas with progressively less entropy loss. Most cooling occurs at late times, $\\sim 10^8-10^9$ yrs, long after the X-ray cavities have disrupted and are impossible to detect. During these late times, slightly denser low entropy gas sinks slowly toward the centers of the h...

  15. Observations on PVP-protected noble metallic nanoparticle deposits upon heating via in situ synchrotron radiation X-ray diffraction.

    Science.gov (United States)

    Song, Jenn-Ming; Chiou, Guan-Di; Chen, Wei-Ting; Chen, Shih-Yun; Kao, Tzu-Hsuan; Chen, In-Gann; Lee, Hsin-Yi

    2011-03-21

    Through monitoring the evolution of the X-ray diffraction peaks, the phase transformation of PVP-protected Ag and Au nanoparticle deposits (NPDs) on electronic substrates of Cu and Ni upon heating in air was investigated via in situ synchrotron radiation X-ray diffraction. With an increasing temperature, the broad diffraction peak of nano-sized Ag and Au particles with the original average diameters of 4.2 nm and 9.6 nm, respectively, became sharp because of particle coarsening and coalescence. Complex phase transitions among Au, Cu, AuCu(3) and CuO(x) were observed, mainly due to the negative enthalpy of mixing between Au and Cu. The interactions between NPDs and the substrates affected the shift of diffraction peaks to lower angles, caused by thermal expansion and also the temperature for the oxide formation. Compared to Au, Ag NPDs did not form intermetallic compounds with Cu and the formation of copper oxides can also be retarded mainly due to the phase separation feature of the Ag-Cu system.

  16. The small angle x-ray scattering of globular proteins in solution during heat denaturation

    Science.gov (United States)

    Banuelos, Jose; Urquidi, Jacob

    2008-10-01

    The ability of proteins to change their conformation in response to changes in their environment has consequences in biological processes like metabolism, chemical regulation in cells, and is believed to play a role in the onset of several neurodegenerative diseases. Factors such as a change in temperature, pressure, and the introduction of ions into the aqueous environment of a protein can give rise to the folding/unfolding of a protein. As a protein unfolds, the ratio of nonpolar to polar groups exposed to water changes, affecting a protein's thermodynamic properties. Using small angle x-ray scattering (SAXS), we are currently studying the intermediate protein conformations that arise during the folding/unfolding process as a function of temperature for five globular proteins. Trends in the observed intermediate structures of these globular proteins, along with correlations with data on protein thermodynamics may help elucidate shared characteristics between all proteins in the folding/unfolding process. Experimental design considerations will be discussed and preliminary results for some of these systems will be presented.

  17. Skull x-ray

    Science.gov (United States)

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

  18. Neck x-ray

    Science.gov (United States)

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

  19. Visualization Of Water Vaporization During Electrical Heating Process With X-ray Tomography

    Science.gov (United States)

    Wang, Jie; Li, Yubin; Erath, Michael; Kantzas, Apostolos

    2007-06-01

    This paper deals with the study of electrical heating as a potential method for recovery of heavy oil and bitumen from unconsolidated sand formations of Northern Alberta. Electrical heating is a preferred energy transfer method for heating relatively shallow formations containing bitumen with limited support for high-pressure steam injection. Simulation results demonstrated that although electrical heating can contribute to the recovery of oil, substantially more oil would be recovered if the formation or injected water were allowed to boil. Thus the in-situ steam creation has been the target of simulation and experimental work presented here.

  20. Experimentally Shock-loaded Anhydrite: Unit-Cell Dimensions, Microstrain and Domain Size from X-Ray Diffraction

    Science.gov (United States)

    Skala, R.; Hoerz, F.

    2003-01-01

    Cretaceous Tertiary (K/T) boundary is traditionally associated with one of the most dramatic mass extinctions in the Earth history. A number of killing mechanisms have been suggested to contribute to the widespread extinctions of Cretaceous biota at this boundary, including severe, global deterioration of the atmosphere and hydrosphere from the shock-induced release of CO2 and SO(x) from carbonate- and sulfate-bearing target rocks, respectively. Recently carried out calculations revealed that the global warming caused by CO2 release was considerably less important than the cooling due to SO(x) gases release during the Chicxulub impact event. Considering apparent potential importance of the response of sulfates to the shock metamorphism, relative lack of the data on shock behavior of sulfates as well as some general difficulties encountered during thermodynamic modeling of the shock-induced CO2 loss from carbonates we subjected anhydrite to a series of shock experiments designed for complete recovery of the shocked material. We report here on the detail X-ray diffraction analysis of seven samples that were subjected to experimental shock-loading from 10 to 65 GPa.

  1. X-ray excited luminescence of polystyrene-based scintillator loaded with LaPO4-Pr nanoparticles

    Science.gov (United States)

    Demkiv, T. M.; Halyatkin, O. O.; Vistovskyy, V. V.; Gektin, A. V.; Voloshinovskii, A. S.

    2016-10-01

    Polystyrene film nanocomposites of 0.3 mm thickness with embedded LaPO4-Pr nanoparticles (40 wt. %) have been synthesized. The luminescent and kinetic properties of these polystyrene composites with embedded LaPO4-Pr nanoparticles upon pulse X-ray excitation have been studied. The luminescence intensity of this polystyrene material significantly increases as it is loaded with inorganic LaPO4-Pr nanoparticles. Nanocomposite films reveal luminescence spectra typical for polystyrene activators (p-Terphenyl and POPOP) and two components of decay time kinetics of luminescence with 12 ns and 2.8 ns time constants, depending on nanoparticle sizes. The component with 12 ns decay constant arises due to the radiative transfer of the 5d-4f-emission of the Pr3+ ions in the LaPO4 nanoparticles to the polystyrene. The decay component with the time constant 2.8 ns originates from luminescence of polystyrene matrix excited by electrons emitted from nanoparticles due to the photoeffect. This nonradiative mechanism of energy transfer from nanoparticles to polystyrene matrices is determinative for nanoparticles, as their sizes are smaller than a mean free path of an electron.

  2. Identification of strain fields in pure Al and hybrid Ni/Al metal foams using X-ray micro-tomography under loading

    Science.gov (United States)

    Fíla, T.; Jiroušek, O.; Jung, A.; Kumpová, I.

    2016-11-01

    Hybrid foams are materials formed by a core from a standard open cell metal foam that is during the process of electrodeposition coated by a thin layer of different nanocrystalline metals. The material properties of the base metal foam are in this way modified resulting in higher plateau stress and, more importantly, by introduction of strain-rate dependence to its deformation response. In this paper, we used time-lapse X-ray micro-tomography for the mechanical characterization of Ni/Al hybrid foams (aluminium open cell foams with nickel coating layer). To fully understand the effects of the coating layer on the material's effective properties, we compared the compressive response of the base uncoated foam to the response of the material with coating thickness of 50 and 75 μm. Digital volume correlation (DVC) was applied to obtain volumetric strain fields of the deforming micro-structure up to the densification region of the deforming cellular structure. The analysis was performed as a compressive mechanical test with simultaneous observation using X-ray radiography and tomography. A custom design experimental device was used for compression of the foam specimens in several deformation states directly in the X-ray setup. Planar X-ray images were taken during the loading phases and a X-ray tomography was performed at the end of each loading phase (up to engineering strain 22%). The samples were irradiated using micro-focus reflection type X-ray tube and images were taken using a large area flat panel detector. Tomography reconstructions were used for an identification of a strain distribution in the foam using digital volumetric correlation. A comparison of the deformation response of the coated and the uncoated foam in uniaxial quasi-static compression is summarized in the paper.

  3. Strategies for in situ laser heating in the diamond anvil cell at an X-ray diffraction beamline

    Energy Technology Data Exchange (ETDEWEB)

    Petitgirard, Sylvain, E-mail: sylvain.petitgirard@uni-bayreuth.de [ID27, European Synchrotron Radiation Facility, 6 rue Jules Horowitz, BP 220, 38043 Grenoble Cedex 9 (France); Bayerisches GeoInstitut (BGI), University of Bayreuth, 95444 Bayreuth (Germany); Salamat, Ashkan, E-mail: sylvain.petitgirard@uni-bayreuth.de [ID27, European Synchrotron Radiation Facility, 6 rue Jules Horowitz, BP 220, 38043 Grenoble Cedex 9 (France); Lyman Laboratory of Physics, Harvard University, Cambridge, MA 02138 (United States); Beck, Pierre [UJF-Grenoble 1/CNRS-INSU, Institut de Planetologie et d’Astrophysique de Grenoble (IPAG), 414 rue de la Piscine, 38000 Grenoble (France); Weck, Gunnar [Commissariat à l’Energie Atomique (CEA), DPTA, 91680 Bruyères le Châtel (France); Bouvier, Pierre [Laboratoire des Materiaux et du Genie Physique, CNRS, Grenoble Institute of Technology, 3 parvis Louis Neel, F-38016 Grenoble (France)

    2013-11-08

    An overview of several innovations regarding in situ laser-heating techniques in the diamond anvil cell at the high-pressure beamline ID27 of the European Synchrotron Radiation Facility is presented. An overview of several innovations regarding in situ laser-heating techniques in the diamond anvil cell at the high-pressure beamline ID27 of the European Synchrotron Radiation Facility is presented. Pyrometry measurements have been adapted to allow simultaneous double-sided temperature measurements with the installation of two additional online laser systems: a CO{sub 2} and a pulsed Nd:YAG laser system. This reiteration of laser-heating advancements at ID27 is designed to pave the way for a new generation of state-of-the-art experiments that demand the need for synchrotron diffraction techniques. Experimental examples are provided for each major development. The capabilities of the double pyrometer have been tested with the Nd:YAG continuous-wave lasers but also in a time-resolved configuration using the nanosecond-pulsed Nd:YAG laser on a Fe sample up to 180 GPa and 2900 K. The combination of time-resolved X-ray diffraction with in situ CO{sub 2} laser heating is shown with the crystallization of a high-pressure phase of the naturally found pyrite mineral MnS{sub 2} (11 GPa, 1100–1650 K)

  4. Optics for coherent X-ray applications.

    Science.gov (United States)

    Yabashi, Makina; Tono, Kensuke; Mimura, Hidekazu; Matsuyama, Satoshi; Yamauchi, Kazuto; Tanaka, Takashi; Tanaka, Hitoshi; Tamasaku, Kenji; Ohashi, Haruhiko; Goto, Shunji; Ishikawa, Tetsuya

    2014-09-01

    Developments of X-ray optics for full utilization of diffraction-limited storage rings (DLSRs) are presented. The expected performance of DLSRs is introduced using the design parameters of SPring-8 II. To develop optical elements applicable to manipulation of coherent X-rays, advanced technologies on precise processing and metrology were invented. With propagation-based coherent X-rays at the 1 km beamline of SPring-8, a beryllium window fabricated with the physical-vapour-deposition method was found to have ideal speckle-free properties. The elastic emission machining method was utilized for developing reflective mirrors without distortion of the wavefronts. The method was further applied to production of diffraction-limited focusing mirrors generating the smallest spot size in the sub-10 nm regime. To enable production of ultra-intense nanobeams at DLSRs, a low-vibration cooling system for a high-heat-load monochromator and advanced diagnostic systems to characterize X-ray beam properties precisely were developed. Finally, new experimental schemes for combinative nano-analysis and spectroscopy realised with novel X-ray optics are discussed.

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

    Science.gov (United States)

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

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

  6. X-Ray Photoelectron Spectroscopy Study of the Heating Effects on Pd/6H-SiC Schottky Structure

    Science.gov (United States)

    Chen, Liang-Yu; Hunter, Gary W.; Neudeck, Philip G.; Knight, Dak

    1998-01-01

    X-ray photoelectron spectroscopy is used to study the effects of heat treatment on the Pd/6H-SiC Schottky diode structure. After heating the structure at 425 C for 140 h, a very thin surface layer of PdO mixed with SiO(x) formed on the palladium surface of the Schottky structure. Heat treatment promoted interfacial diffusion and reaction which significantly broadened the interfacial region. In the interfacial region, the palladium concentration decreases with depth, and the interfacial products are Pd(x)Si (x = 1,2,3,4). In the high Pd concentration regions, Pd4Si is the major silicide component while gr and Pd2Si are major components in the low Pd concentration region. At the center of the interface, where the total palladium concentration equals that of silicon, the concentrations of palladium associated with various palladium silicides (Pd(x)Si, x= 1,2,3,4) are approximately equal. The surface passivation layer composed of PdO and SiO, may significantly affect the electronic and catalytic properties of the surface of the Schottky diode which plays a major role in gas detection. The electronic properties of the Schottky structure may be dominated by a (Pd+Pd(x)Si)/SiC interface. In order to stabilize the properties of the Schottky structure the surface and interface diffusion and reactions must be controlled.

  7. LACTOSE BINDING TO HEAT-LABILE ENTEROTOXIN REVEALED BY X-RAY CRYSTALLOGRAPHY

    NARCIS (Netherlands)

    SIXMA, TK; PRONK, SE; KALK, KH; VANZANTEN, BAM; HOL, WGJ

    1992-01-01

    RECOGNITION of the oligosaccharide portion of ganglioside G(M1) in membranes of target cells by the heat-labile enterotoxin from Escherichia coli is the crucial first step in its pathogenesis, as it is for the closely related cholera toxin 1-3. These toxins have five B subunits, which are essential

  8. LACTOSE BINDING TO HEAT-LABILE ENTEROTOXIN REVEALED BY X-RAY CRYSTALLOGRAPHY

    NARCIS (Netherlands)

    SIXMA, TK; PRONK, SE; KALK, KH; VANZANTEN, BAM; HOL, WGJ

    1992-01-01

    RECOGNITION of the oligosaccharide portion of ganglioside G(M1) in membranes of target cells by the heat-labile enterotoxin from Escherichia coli is the crucial first step in its pathogenesis, as it is for the closely related cholera toxin 1-3. These toxins have five B subunits, which are essential

  9. Three-dimensional numerical analysis of convection and conduction cooling of spherical biocrystals with localized heating from synchrotron X-ray beams.

    Science.gov (United States)

    Mhaisekar, Ashutosh; Kazmierczak, Michael J; Banerjee, Rupak

    2005-05-01

    The differential momentum and thermal energy equations for fluid flow and convective heat-transfer around the sample biocrystal, with coupled internal heat conduction, are solved using advanced computational fluid dynamics techniques. Average \\bar{h} as well as local h(theta) values of the convective heat-transfer coefficients are obtained from the fundamental equations. The results of these numerical solutions show the three-dimensional fluid flow field around the sample in conjunction with the detailed internal temperature distribution inside the crystal. The external temperature rise and maximum internal temperature increase are reported for various cases. The effect of the important system parameters, such as gas velocity and properties, crystal size and thermal conductivity and incident beam conditions (intensity and beam size), are all illustrated with comparative examples. For the reference case, an external temperature rise of 7 K and internal temperature increase of 0.5 K are calculated for a 200 microm-diameter cryocooled spherical biocrystal subjected to a 13 keV X-ray beam of 4 x 10(14) photons s(-1) mm(-2) flux density striking half the sample. For all the cases investigated, numerical analysis shows that the controlling thermal resistance is the rate of convective heat-transfer and not internal conduction. Thermal diffusion results in efficient thermal spreading of the deposited energy and this results in almost uniform internal crystal temperatures (DeltaT(internal) approximately 0.5 K), in spite of the non-uniform h(theta) with no more than 1.3 K internal temperature difference for the worst case of localized and focused beam heating. Rather, the major temperature variation occurs between the outer surface of the crystal/loop system and the gas stream, T(s) - T(gas), which itself is only about DeltaT(external) approximately 5-10 K, and depends on the thermal loading imposed by the X-ray beam, the rate of convection and the size of the loop

  10. Pulsar Polar Cap Heating and Surface Thermal X-Ray Emission. II. Inverse Compton Radiation Pair Fronts

    CERN Document Server

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

    2002-01-01

    We investigate the production of electron-positron pairs by inverse Compton scattered (ICS) photons above a pulsar polar cap (PC) and surface heating by returning positrons. This paper is a continuation of our self-consistent treatment of acceleration, pair dynamics and electric field screening above pulsar PCs. We calculate the altitude of the inverse Compton pair formation fronts, the flux of returning positrons and present the heating efficiencies and X-ray luminosities. We revise pulsar death lines implying cessation of pair formation, and present them in surface magnetic field-period space. We find that virtually all known radio pulsars are capable of producing pairs by resonant and non-resonant ICS photons radiated by particles accelerated above the PC in a pure star-centered dipole field, so that our ICS pair death line coincides with empirical radio pulsar death. Our calculations show that ICS pairs are able to screen the accelerating electric field only for high neutron star surface temperatures and ...

  11. Chest X Ray?

    Science.gov (United States)

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

  12. X-Rays

    Science.gov (United States)

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

  13. Medical X-Rays

    Science.gov (United States)

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

  14. Cryotomography x-ray microscopy state

    Science.gov (United States)

    Le Gros, Mark; Larabell, Carolyn A.

    2010-10-26

    An x-ray microscope stage enables alignment of a sample about a rotation axis to enable three dimensional tomographic imaging of the sample using an x-ray microscope. A heat exchanger assembly provides cooled gas to a sample during x-ray microscopic imaging.

  15. Heat Loss in a Laser-Driven, Magnetized, X-Ray Source with Thermoelectric Terms

    Science.gov (United States)

    Giuliani, J. L.; Velikovich, A. L.; Kemp, G. E.; Colvin, J. D.; Koning, J.; Fournier, K. B.

    2016-10-01

    The efficiency of laser-driven K-shell radiation sources, i.e., pipes containing a gas or a metal foam, may be improved by using an axial magnetic field to thermally insulate the pipe wall from the hot interior. A planar, self-similar solution for the magnetic and thermal diffusion is developed to model the near wall physics that includes the thermoelectric Nernst and Ettingshausen effects. This solution extends previous work for the MagLIF concept to include the full dependence of the transport coefficients on the electron Hall parameter. The analytic solution assumes a constant pressure. This case is matched with a 1D MHD code, which is then applied to the case allowing for pressure gradients. These numerical solutions are found to evolve toward the self-similar ones. The variation of the time integrated heat loss with and without the thermoelectric terms will be examined. The present work provides a verification test for general MHD codes that use Braginskii's or Epperlein-Haines' transport model to account for thermoelectric effects. NRL supported by the DOE/NNSA. LLNL work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract No. DE-AC52-07NA27344.

  16. Effects of heat treatment on red gemstone spinel: single-crystal X-ray, Raman, and photoluminescence study

    Science.gov (United States)

    Widmer, Remo; Malsy, Anna-Kathrin; Armbruster, Thomas

    2015-04-01

    A red spinel, MgAl2O4, from Burma (Myanmar) containing as chromophores ca. 0.5 wt% of each Cr2O3 and V2O3, was sequentially heated for at least 72 h at temperatures ranging from 600 °C to 1,100 °C. The untreated and quenched samples were examined with single-crystal X-ray diffraction (XRD), Raman spectroscopy and photoluminescence spectroscopy. XRD results display a linear decrease of the cell parameter a and a continuous shift of the oxygen coordinate u, u, u at 3 m toward lower values with increasing temperature and associated Mg, Al disorder: T(Mg1- x Al x )M(Al2- x Mg x )O4. The natural spinel has x = 0.157(2) and reaches x = 0.286(4) after quenching from 1,100 °C. In its natural state, M-O and T-O distances are 1.9226(2) and 1.9361(4) Å. With increasing inversion of Mg from the tetrahedrally coordinated T to the octahedrally coordinated M site, M-O distances increase at 1,100 °C to 1.9333(4) Å and T-O distances decrease to 1.9130(8) Å. The crossover temperature, at which T-O and M-O distances become equal (i.e., 1.927 Å), is found to be at 650 °C and corresponds to an inversion parameter x = 0.208(3). With increasing heat treatment, Raman spectra of quenched samples become significantly broadened and a peak characteristic for Mg, Al disorder at 721 cm-1 firstly appears for a crystal quenched from 800 °C with x = 0.248(4). At room temperature, photoluminescence spectra are dominated by a strong R line at 684.5 nm accompanied by poorly resolved N lines: N1 (687 nm), N2 (688 nm), and N3 (689 nm). N lines are caused by different Mg, Al environments of Cr3+. With increasing inversion parameter ( x), the R line decreases in intensity and the N lines become prominent leading to strongly broadened peaks with a maximum shifted toward higher wave lengths (687.5 nm at 1,100 °C). Criteria for the detection of heat treatment on gemstone spinel applicable to gemological routine examination are provided. Extrapolation of u, a, and bond lengths from heat

  17. Speciation of zinc in municipal solid waste incineration fly ash after heat treatment: an X-ray absorption spectroscopy study.

    Science.gov (United States)

    Struis, Rudolf P W J; Ludwig, Christian; Lutz, Harald; Scheidegger, André M

    2004-07-01

    Fly ash is commonly deposited in special landfills as it contains toxic concentrations of heavy metals, such as Zn, Pb, Cd, and Cu. This study was inspired by our efforts to detoxify fly ash from municipal solid waste incineration by thermal treatment to produce secondary raw materials suited for reprocessing. The potential of the thermal treatment was studied by monitoring the evaporation rate of zinc from a certified fly ash (BCR176) during heating between 300 and 950 degrees C under different carrier gas compositions. Samples were quenched at different temperatures for subsequent investigation with X-ray absorption spectroscopy (XAS). The XAS spectra were analyzed using principal component analysis (PCA), target transformation (TT), and linear combination fitting (LCF) to analyze the major Zn compounds in the fly ash as a function of the temperature. The original fly ash comprised about 60% zinc oxides mainly in the form of hydrozincite (Zn5(OH)6(CO3)2) and 40% inerts like willemite (Zn2SiO4) and gahnite (ZnAl2O4) in a weight ratio of about 3:1. At intermediate temperatures (550-750 degrees C) the speciation underlines the competition between indigenous S and Cl with solid zinc oxides to form either volatile ZnCl2 or solid ZnS. ZnS then transformed into volatile species at about 200 degrees C higher temperatures. The inhibiting influence of S was found absent when oxygen was introduced to the inert carrier gas stream or chloride-donating alkali salt was added to the fly ash.

  18. Flow visualization and void fraction measurement in liquid-metal/water direct contact heat exchange by X-ray attenuation technique

    Science.gov (United States)

    Liu, Xin

    One concept being considered for steam generation in particular next generation nuclear reactor designs, involves water coming into direct contact with a circulating molten metal. To optimize the design of such direct contact heat exchange and vaporization systems, detailed knowledge is necessary of the various flow regimes, interfacial transport phenomena, heat transfer and operational stability. With the development of high performance digital detectors, radiography using X-rays or neutrons maybe a suitable technique to obtain information about that direct-contact interaction; i.e., void volume fractions, length scales and dynamic behavior. Under the basis of previous investigations, a complete methodology of the X-ray radiography for two-phase flow measurement has been developed from the facility and imaging analysis aspects. Through this developed methodology, a high energy X-ray imaging system is optimized for the direct-contact heat exchange experiment. Beside an on-line calibration procedure which practically quantifies the imaging system's performance, the extended linear system theory and Rose's model have also been used to evaluate the imaging system's performance, respectively. The bottleneck of the current imaging system and the future of system improvement direction have been pointed out. With our real-time, large-area high energy X-ray imaging system, the two-phase flow was visualized and stored digitally. An efficient image processing strategy has also been established by combining several optimal digital image processing algorithms. The approach has been implemented into a software computational tool written in MATLAB called T-XIP. Time-dependent heat transfer related variables, such as void fraction (void volume), local heat transfer coefficient, etc., were calculated using this software tool. Finally, an error analysis associated with the void fraction measurement has been given based on two procedures.

  19. The behavior of single-crystal silicon to dynamic loading using in-situ X-ray diffraction and phase contrast imaging

    Science.gov (United States)

    Lee, Hae Ja; Xing, Zhou; Galtier, Eric; Arnold, Brice; Granados, Eduardo; Brown, Shaughnessy B.; Tavella, Franz; McBride, Emma; Fry, Alan; Nagler, Bob; Schropp, Andreas; Seiboth, Frank; Samberg, Dirk; Schroer, Christian; Gleason, Arianna E.; Higginbotham, Andrew

    Hydrostatic and uniaxial compression studies have revealed that crystalline silicon undergoes phase transitions from a cubic diamond structure to a variety of phases including orthorhombic Imma phase, body-centered tetragonal phase, and a hexagonal primitive phase. The dynamic response of silicon at high pressure, however, is not well understood. Phase contrast imaging has proven to be a powerful tool for probing density changes caused by the shock propagation into a material. In order to characterize the elastic and phase transitions, we image shock waves in Si with high spatial resolution using the LCLS X-ray free electron laser and Matter in Extreme Conditions instrument. In this study, the long pulse optical laser with pseudo-flat top shape creates high pressures up to 60 GPa. We measure the crystal structure by observing X-ray diffraction orthogonal to the shock propagation direction over a range of pressures. We describe the capability of simultaneously performing phase contrast imaging and in situ X-ray diffraction during shock loading and discuss the dynamic response of Si in high-pressure phases Use of the Linac Coherent Light Source (LCLS), SLAC National Accelerator Laboratory, is supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences under Contract No. DE-AC02-76SF00515. The MEC instrument is supported by.

  20. [Heat-induced structural transition of alpha-crystallin in the eye lens tissue observed by small-angle X-ray scattering].

    Science.gov (United States)

    Krivandin, A V

    2009-01-01

    Heat-induced structural transitions of crystallins in the eye lens tissue have been studied by small-angle X-ray scattering. It was shown that a short-time (approximately 1 min) incubation of the bovine eye lens tissue at a temperature of about 60 degrees C leads to a pronounced shift of the small-angle X-ray diffraction maximum due to the short-range order of alpha-crystallin oligomers. This shift indicates an increase in the molecular mass of alpha-crystallin oligomers. The results are evidence that, in the native surrounding and at the native concentration of alpha-crystallin, heat-induced transition of alpha-crystallin quaternary structure takes place. Earlier, this transition of alpha-crystallin has been observed only in solutions and gels of this protein. The results confirm the identity of alpha-crystallin properties in vitro and in vivo.

  1. Small angle neutron scattering and small angle X-ray scattering studies of platinum-loaded carbon foams

    Indian Academy of Sciences (India)

    P U Sastry; V K Aswal; A G Wagh

    2008-11-01

    The morphology of carbon nanofoam samples comprising platinum nanoparticles dispersed in the matrix was characterized by small angle neutron scattering (SANS) and small angle X-ray scattering (SAXS) techniques. Results show that the structure of pores of carbon matrix exhibits a mass (pore) fractal nature and the average radius of the platinum particles is about 2.5 nm. The fractal dimension as well as the size distribution parameters of platinum particles varies markedly with the platinum content and annealing temperature. Transmission electron micrographs of the samples corroborate the SANS and SAXS results.

  2. Probing the K-edge of a laser heated aluminum plasma using X-rays from betatron oscillations in a laser wakefield accelerator with femtosecond resolution

    Science.gov (United States)

    Behm, Keegan; Hussein, Amina; Zhao, Tony; Hill, Edward; Maksimchuk, Anatoly; Nees, John; Yanovsky, Victor; Mangles, Stuart; Krushelnick, Karl; Thomas, Alexander; CenterUltrafast Optical Science Team; Plasmas Group Team

    2016-10-01

    Presented here are data from a two-beam pump-probe experiment. We used synchrotron-like X-rays created by betatron oscillations to probe a thin metal foil that is pumped by the secondary laser beam. The Hercules Ti:Sapphire laser facility was operated with a pulse duration of 34 fs and a power of 80 TW split. A 75-25 beam splitter was used to drive a laser wakefield accelerator and heat the secondary target. We observed opacity changes around the K-edge of thin aluminum foil as it was heated by an ultrafast pump laser. To understand how the opacity is changing with heating and expansion of the plasma, the delay between the two laser paths was adjusted on a femtosecond time scale from 50 to 400 fs. Experimental data for aluminum shows variation in opacity around the K-edge with changes in the probe delay. The transmitted synchrotron-like spectrum was measured using single photon counting on an X-ray CCD camera and was available on a shot-by-shot basis. The success of this work demonstrates a practical application for X-rays produced from betatron oscillations in a wakefield accelerator. U.S. Department of Energy and the National Nuclear Security Administration.

  3. Potential cooling of an accretion-heated neutron star crust in the low-mass X-ray binary 1RXS J180408.9-342058

    CERN Document Server

    Parikh, Aastha S; Degenaar, Nathalie; Ootes, Laura S; Page, Dany; Altamirano, Diego; Cackett, Edward M; Deller, Adam T; Gusinskaia, Nina; Hessels, Jason W T; Homan, Jeroen; Linares, Manuel; Miller, Jon M; Miller-Jones, James C A

    2016-01-01

    We have monitored the transient neutron star low-mass X-ray binary 1RXS J180408.9-342058 in quiescence after the end of its ~4.5 month outburst in 2015. The source has been observed 34 times using Swift and once using XMM-Newton in order to study the cooling of an accretion heated neutron star crust. During both the Swift and the XMM-Newton observations the X-ray spectra were dominated by a thermal component. The thermal evolution showed a gradual decay in the X-ray luminosity from ~18x10^32 to ~4x10^32 (D/5.8 kpc)^2 erg s^{-1} and the inferred neutron star surface temperature (for an observer at infinity) decreased from ~100 to ~72 eV between ~8 to ~379 days after the end of outburst. This can be interpreted as cooling of a neutron star crust that had been heated due to accretion during the preceding outburst. Modeling the observed temperature curve with the thermal evolution code NSCool indicated that the source required ~1.9 MeV per accreted nucleon of shallow heating in addition to the standard deep crust...

  4. Characterization of white poplar and eucalyptus after ionic liquid pretreatment as a function of biomass loading using X-ray diffraction and small angle neutron scattering

    Energy Technology Data Exchange (ETDEWEB)

    Yuan, Xueming [Beijing Univ. of Chemical Technology (China); Duan, Yonghao [Beijing Univ. of Chemical Technology (China); He, Lilin [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Singh, Seema [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Joint BioEnergy Inst. (JBEI), Emeryville, CA (United States); Simmons, Blake [Joint BioEnergy Inst. (JBEI), Emeryville, CA (United States); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Cheng, Gang [Beijing Univ. of Chemical Technology (China); Joint BioEnergy Inst. (JBEI), Emeryville, CA (United States); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2017-02-08

    A systematic study was done to understand interactions among biomass loading during ionic liquid (IL) pretreatment, biomass type and biomass structures. White poplar and eucalyptus samples were pretreated using 1-ethyl-3-methylimidazolium acetate (EmimOAc) at 110 °C for 3 h at biomass loadings of 5, 10, 15, 20 and 25 wt%. All of the samples were chemically characterized and tested for enzymatic hydrolysis. Physical structures including biomass crystallinity and porosity were measured by X-ray diffraction (XRD) and small angle neutron scattering (SANS), respectively. SANS detected pores of radii ranging from ~25 to 625 Å, enabling assessment of contributions of pores with different sizes to increased porosity after pretreatment. Contrasting dependences of sugar conversion on white poplar and eucalyptus as a function of biomass loading were observed and cellulose crystalline structure was found to play an important role.

  5. Extremity x-ray

    Science.gov (United States)

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

  6. Abdominal x-ray

    Science.gov (United States)

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

  7. Thermal management of next-generation contact-cooled synchrotron x-ray mirrors

    Energy Technology Data Exchange (ETDEWEB)

    Khounsary, A.

    1999-10-29

    In the past decade, several third-generation synchrotrons x-ray sources have been constructed and commissioned around the world. Many of the major problems in the development and design of the optical components capable of handling the extremely high heat loads of the generated x-ray beams have been resolved. It is expected, however, that in the next few years even more powerful x-ray beams will be produced at these facilities, for example, by increasing the particle beam current. In this paper, the design of a next generation of synchrotron x-ray mirrors is discussed. The author shows that the design of contact-cooled mirrors capable of handing x-ray beam heat fluxes in excess of 500 W/mm{sup 2} - or more than three times the present level - is well within reach, and the limiting factor is the thermal stress rather then thermally induced slope error.

  8. Plasma heating in a post eruption Current Sheet: a case study based on ultraviolet, soft, and hard X-ray data

    CERN Document Server

    Susino, Roberto; Krucker, Säm

    2013-01-01

    Off-limb observations of the solar corona after Coronal Mass Ejections (CMEs) often show strong, compact, and persistent UV sources behind the eruption. They are primarily observed by the SOHO/UVCS instrument in the "hot" Fe XVIII {\\lambda}974 {\\AA} line and are usually interpreted as a signature of plasma heating due to magnetic reconnection in the post-CME Current Sheet (CS). Nevertheless, the physical process itself and the altitude of the main energy release are currently not fully understood. In this work, we studied the evolution of plasma heating after the CME of 2004 July 28 by comparing UV spectra acquired by UVCS with soft X-ray (SXR) and hard X-ray (HXR)images of the post-flare loops taken by GOES/SXI and RHESSI. The X-ray data show a long-lasting extended source that is rising upwards, toward the high-temperature source detected by UVCS. UVCS data show the presence of significant non-thermal broadening in the CS (signature of turbulent motions) and a strong density gradient across the CS region. T...

  9. Potential cooling of an accretion-heated neutron star crust in the low-mass X-ray binary 1RXS J180408.9-342058

    Science.gov (United States)

    Parikh, A. S.; Wijnands, R.; Degenaar, N.; Ootes, L. S.; Page, D.; Altamirano, D.; Cackett, E. M.; Deller, A. T.; Gusinskaia, N.; Hessels, J. W. T.; Homan, J.; Linares, M.; Miller, J. M.; Miller-Jones, J. C. A.

    2017-01-01

    We have monitored the transient neutron star low-mass X-ray binary 1RXS J180408.9-342058 in quiescence after its ˜4.5 month outburst in 2015. The source has been observed using Swift and XMM-Newton. Its X-ray spectra were dominated by a thermal component. The thermal evolution showed a gradual X-ray luminosity decay from ˜18 × 1032 to ˜4 × 1032 (D/5.8 kpc)2 erg s-1 between ˜8 to ˜379 days in quiescence and the inferred neutron star surface temperature (for an observer at infinity; using a neutron star atmosphere model) decreased from ˜100 to ˜71 eV. This can be interpreted as cooling of an accretion heated neutron star crust. Modeling the observed temperature curve (using NSCOOL) indicated that the source required ˜1.9 MeV per accreted nucleon of shallow heating in addition to the standard deep crustal heating to explain its thermal evolution. Alternatively, the decay could also be modelled without the presence of deep crustal heating, only having a shallow heat source (again ˜1.9 MeV per accreted nucleon was required). However, the XMM-Newton data statistically required an additional power-law component. This component contributed ˜30 per cent of the total unabsorbed flux in 0.5 - 10 keV energy range. The physical origin of this component is unknown. One possibility is that it arises from low-level accretion. The presence of this component in the spectrum complicates our cooling crust interpretation because it might indicate that the smooth luminosity and temperature decay curves we observed may not be due to crust cooling but due to some other process.

  10. X-Ray Supernovae

    CERN Document Server

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

    2002-01-01

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

  11. Thermal management of masks for deep x-ray lithography.

    Energy Technology Data Exchange (ETDEWEB)

    Khounsary, A.; Chojnowski, D.; Mancini, D.C.; Lai, B.; Dejus, R.

    1997-11-18

    This paper addresses some options and techniques in the thermal management of masks used in deep x-ray lithography. The x-ray masks are thin plates made of low-atomic-number materials on which a patterned thin film of a high-atomic-number metal has been deposited. When they are exposed to an x-ray beam, part of the radiation is transmitted to replicate the pattern on a downstream photoresist, and the remainder is absorbed in the mask in the form of heat. This heat load can cause deformation of the mask and thus image distortion in the lithography process. The mask geometry considered in the present study is 100 mm x 100 mm in area, and about 0.1 to 2 mm thick. The incident radiation is a bending magnet x-ray beam having a footprint of 60 mm x 4 mm at the mask. The mask is scanned vertically about {+-} 30 mm so that a 60 mm x 60 mm area is exposed. the maximum absorbed heat load in the mask is 80 W, which is significantly greater than a few watts encountered in previous systems. In this paper, cooling techniques, substrate material selection, transient and steady state thermal and structural behavior, and other thermo-mechanical aspects of mask design are discussed. It is shown that, while diamond and graphite remain attractive candidates, at present beryllium is a more suitable material for this purpose and, when properly cooled, can provide the necessary dimensional tolerance.

  12. X-rays from the youngest stars

    Science.gov (United States)

    Feigelson, Eric D.

    1994-01-01

    The X-ray properties of classical and weak-lined T Tauri stars are briefly reviewed, emphasizing recent results from the ROSAT satellite and prospects for ASCA. The interpretation of the high level of T Tauri X-rays as enhanced solar-type magnetic activity is discussed and criticized. The census of X-ray emitters is significantly increasing estimates of galactic star formation efficiency, and X-ray emission may be important for self-regulation of star formation. ASCA images will detect star formation regions out to several kiloparsecs and will study the magnetically heated plasma around T Tauri stars. However, images will often suffer from crowding effects.

  13. X-Ray Polarimetry

    CERN Document Server

    Kaaret, Philip

    2014-01-01

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

  14. Nanoradian angular stabilization of x-ray optical components.

    Science.gov (United States)

    Stoupin, Stanislav; Lenkszus, Frank; Laird, Robert; Goetze, Kurt; Kim, Kwang-Je; Shvyd'ko, Yuri

    2010-05-01

    An x-ray free-electron laser oscillator (XFELO) has been recently proposed [K. Kim et al., Phys. Rev. Lett. 100, 244802 (2008)]. Angular orientation and position in space of Bragg mirrors of the XFELO optical cavity must be continuously adjusted to compensate for the instabilities and maximize the output intensity. An angular stability of about 10 nrad (rms) is required [K. Kim and Y. Shvyd'ko, Phys. Rev. ST Accel. Beams 12, 030703 (2009)]. To approach this goal, a feedback loop based on a null-detection principle was designed and used for stabilization of a high-energy-resolution x-ray monochromator (DeltaE/E approximately 4 x 10(-8), E=23.7 keV) and a high-heat-load monochromator. Angular stability of about 13 nrad (rms) has been demonstrated for x-ray optical elements of the monochromators.

  15. Nanoradian angular stabilization of x-ray optical components

    CERN Document Server

    Stoupin, Stanislav; Laird, Robert; Goetze, Kurt; Kim, Kwang-Je; Shvydko, Yuri

    2010-01-01

    An x-ray free electron laser oscillator (XFELO) has been recently proposed [K. Kim, Y. Shvyd'ko, and S. Reiche, Phys. Rev. Lett. 100, 244802 (2008)]. Angular orientation and position in space of Bragg mirrors of the XFELO optical cavity must be continuously adjusted to compensate instabilities and maximize the output intensity. An angular stability of about 10 nrad (rms) is required [K. Kim and Y. Shvyd'ko Phys. Rev. STAB 12, 030703 (2009)]. To approach this goal, a feedback loop based on a null-detection principle was designed and used for stabilization of a high energy resolution x-ray monochromator ($\\Delta E/E \\simeq 4 \\times 10^{-8}$, $E$ = 23.7 keV) and a high heat load monochromator. Angular stability of about 13 nrad (rms) has been demonstrated for x-ray optical elements of the monochromators.

  16. First Results from Laser-Driven MagLIF Experiments on OMEGA: Time Evolution of Laser Gas Heating Using Soft X-Ray Diagnostics

    Science.gov (United States)

    Barnak, D. H.; Betti, R.; Chang, P.-Y.; Davies, J. R.

    2015-11-01

    Magnetized liner inertial fusion (MagLIF) is a promising inertial confinement fusion scheme comprised of three stages: axial magnetization, laser heating of the deuterium -tritium gas fill, and compression of the gas by the liner. To study the physics of MagLIF, a scaled-down version has been designed and implemented on the OMEGA-60 laser. This talk will focus primarily on the heating process of a MagLIF target using a 351-nm laser. A neon-doped deuterium gas capsule was heated using a 2.5-ns square pulse delivering 200 J of laser energy. Spectral analysis of the x-ray emission from the side and the laser entrance hole of the capsule is used to infer the time evolution of the gas temperature. The x-ray spectra for a grid of possible gas temperatures and densities are simulated using Spect3D atomic modeling software. The simulation results are then used to deconvolve the raw signals and obtain density and temperature estimations. A gas temperature lower bound of 100 eV at 1.3 ns after the start of the laser pulse can be inferred from these estimations. The estimations are then compared to 2-D hydrocode modeling. This material is based upon work supported by the Department of Energy National Nuclear Security Administration under Award Number DE-NA0001944 and by DE-FG02-04ER54786 and DE-FC02-04ER54789 (Fusion Science Center).

  17. In situ X-ray diffraction study of crystallization process of GeSbTe thin films during heat treatment

    Energy Technology Data Exchange (ETDEWEB)

    Kato, Naohiko [Toyota Central R and D Labs., Inc., Nagakute, Aichi 480-1192 (Japan)]. E-mail: e0957@mosk.tytlabs.co.jp; Konomi, Ichiro [Toyota Central R and D Labs., Inc., Nagakute, Aichi 480-1192 (Japan); Seno, Yoshiki [Toyota Central R and D Labs., Inc., Nagakute, Aichi 480-1192 (Japan); Motohiro, Tomoyoshi [Toyota Central R and D Labs., Inc., Nagakute, Aichi 480-1192 (Japan)

    2005-05-15

    The crystallization processes of the Ge{sub 2}Sb{sub 2}Te{sub 5} thin film used for PD and DVD-RAM were studied in its realistic optical disk film configurations for the first time by X-ray diffraction using an intense X-ray beam of a synchrotron orbital radiation facility (SPring-8) and in situ quick detection with a Position-Sensitive-Proportional-Counter. The dependence of the amorphous-to-fcc phase-change temperature T{sub 1} on the rate of temperature elevation R{sub et} gave an activation energy E{sub a}: 0.93 eV much less than previously reported 2.2 eV obtained from a model sample 25-45 times thicker than in the real optical disks. The similar measurement on the Ge{sub 4}Sb{sub 1}Te{sub 5} film whose large reflectance change attains the readability by CD-ROM drives gave E{sub a}: 1.13 eV with larger T{sub 1} than Ge{sub 2}Sb{sub 2}Te{sub 5} thin films at any R{sub et} implying a lower sensitivity in erasing as well as a better data stability of the phase-change disk.

  18. DIELECTRICALLY-LOADED WAVEGUIDE AS A MICROWAVE UNDULATOR FOR HIGH BRILLANCE X-RAYS AT 45 – 90 KeV

    Energy Technology Data Exchange (ETDEWEB)

    Kustom, R. L.; Waldschmidt, G.; Nassiri, A.

    2017-06-01

    The HEM12 mode in a cylindrical, dielectrically-loaded waveguide provides E and H fields on the central axis that are significantly higher than the fields on the conducting walls. This structure, operating near the cutoff frequency of the HEM12 mode, spans a frequency range where the wavelength and phase velocity vary significantly. This property can be exploited to generate undulator action with short periods for the generation of high brightness xrays. The frequency range of interest would be from 18 to 34.5-GHz. The goal would be to generate x-rays on the fundamental mode over a range of 45 to 90-keV.The tunability would be achieved by changing the source frequency while maintaining a constant on-axis equivalent undulator field strength of 0.5-T.

  19. The feasibility of polychromatic cone-beam x-ray fluorescence computed tomography (XFCT) imaging of gold nanoparticle-loaded objects: a Monte Carlo study

    Energy Technology Data Exchange (ETDEWEB)

    Jones, Bernard L; Cho, Sang Hyun, E-mail: scho@gatech.edu [Nuclear/Radiological Engineering and Medical Physics Programs, Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA 30332-0405 (United States)

    2011-06-21

    A recent study investigated the feasibility to develop a bench-top x-ray fluorescence computed tomography (XFCT) system capable of determining the spatial distribution and concentration of gold nanoparticles (GNPs) in vivo using a diagnostic energy range polychromatic (i.e. 110 kVp) pencil-beam source. In this follow-up study, we examined the feasibility of a polychromatic cone-beam implementation of XFCT by Monte Carlo (MC) simulations using the MCNP5 code. In the current MC model, cylindrical columns with various sizes (5-10 mm in diameter) containing water loaded with GNPs (0.1-2% gold by weight) were inserted into a 5 cm diameter cylindrical polymethyl methacrylate phantom. The phantom was then irradiated by a lead-filtered 110 kVp x-ray source, and the resulting gold fluorescence and Compton-scattered photons were collected by a series of energy-sensitive tallies after passing through lead parallel-hole collimators. A maximum-likelihood iterative reconstruction algorithm was implemented to reconstruct the image of GNP-loaded objects within the phantom. The effects of attenuation of both the primary beam through the phantom and the gold fluorescence photons en route to the detector were corrected during the image reconstruction. Accurate images of the GNP-containing phantom were successfully reconstructed for three different phantom configurations, with both spatial distribution and relative concentration of GNPs well identified. The pixel intensity of regions containing GNPs was linearly proportional to the gold concentration. The current MC study strongly suggests the possibility of developing a bench-top, polychromatic, cone-beam XFCT system for in vivo imaging.

  20. The feasibility of polychromatic cone-beam x-ray fluorescence computed tomography (XFCT) imaging of gold nanoparticle-loaded objects: a Monte Carlo study

    Science.gov (United States)

    Jones, Bernard L.; Cho, Sang Hyun

    2011-06-01

    A recent study investigated the feasibility to develop a bench-top x-ray fluorescence computed tomography (XFCT) system capable of determining the spatial distribution and concentration of gold nanoparticles (GNPs) in vivo using a diagnostic energy range polychromatic (i.e. 110 kVp) pencil-beam source. In this follow-up study, we examined the feasibility of a polychromatic cone-beam implementation of XFCT by Monte Carlo (MC) simulations using the MCNP5 code. In the current MC model, cylindrical columns with various sizes (5-10 mm in diameter) containing water loaded with GNPs (0.1-2% gold by weight) were inserted into a 5 cm diameter cylindrical polymethyl methacrylate phantom. The phantom was then irradiated by a lead-filtered 110 kVp x-ray source, and the resulting gold fluorescence and Compton-scattered photons were collected by a series of energy-sensitive tallies after passing through lead parallel-hole collimators. A maximum-likelihood iterative reconstruction algorithm was implemented to reconstruct the image of GNP-loaded objects within the phantom. The effects of attenuation of both the primary beam through the phantom and the gold fluorescence photons en route to the detector were corrected during the image reconstruction. Accurate images of the GNP-containing phantom were successfully reconstructed for three different phantom configurations, with both spatial distribution and relative concentration of GNPs well identified. The pixel intensity of regions containing GNPs was linearly proportional to the gold concentration. The current MC study strongly suggests the possibility of developing a bench-top, polychromatic, cone-beam XFCT system for in vivo imaging.

  1. Separation of Joule Heating and Peltier Cooling via Time-Resolved X-Ray Di?raction in Si/SiGe Superlattice

    Science.gov (United States)

    Kozina, Michael; Fuchs, Matthias; Chen, Jian; Jiang, Mason; Chen, Pice; Evans, Paul; Vermeersch, Bjorn; Bahk, Je-Hyeong; Shakouri, Ali; Brewe, Dale; Reis, David

    2012-02-01

    We present detailed measurements of the thermal pro?le in a pulsed current SiGe-based thermoelectric micro-cooler. The evolution of heat ?ow in thermoelectric materials has been previously studied using time-domain thermore?ectance imaging; however, such methods are typically only sensitive to the surface temperature of the device, and the heat ?ow into the material remains hidden. Using time-resolved x-ray di?raction, we probe the transient temperature change in both the surface gold electrode and the underlying Si/SiGe superlattice using the shift in diffraction pattern caused by thermal expansion. We are also able to resolve Joule heating vs. Peltier cooling taking place in the gold through separation of timescales made possible by the relatively short duration (100ps) of the Advanced Photon Source.

  2. In situ X-ray Diffraction Study of Graphitic Carbon Formed During Heating and Cooling of Amorphous-C/Ni bilayers

    Energy Technology Data Exchange (ETDEWEB)

    Saenger, K.; Tsang, J; Bol, A; Chu, J; Grill, A; Lavoie, C

    2010-01-01

    We examine graphitization of amorphous carbon (a-C) in a-C/Ni bilayer samples having the structure Si/SiO{sub 2}/a-C(3-30 nm)/Ni(100 nm). In situ x-ray diffraction (XRD) measurements during heating in He at 3 C/s to 1000 C showed graphitic C formation beginning at temperatures T of 640-730 C, suggesting graphitization by direct metal-induced crystallization, rather than by a dissolution/precipitation mechanism in which C is dissolved during heating and expelled from solution upon cooling. We also find that graphitic C, once formed, can be reversibly dissolved by heating to T > 950 C, and that nongraphitic C can be volatilized by annealing in H{sub 2}-containing ambients.

  3. CONTINUED NEUTRON STAR CRUST COOLING OF THE 11 Hz X-RAY PULSAR IN TERZAN 5: A CHALLENGE TO HEATING AND COOLING MODELS?

    Energy Technology Data Exchange (ETDEWEB)

    Degenaar, N.; Miller, J. M. [Department of Astronomy, University of Michigan, 500 Church Street, Ann Arbor, MI 48109 (United States); Wijnands, R.; Altamirano, D.; Fridriksson, J. [Astronomical Institute Anton Pannekoek, University of Amsterdam, Postbus 94249, 1090 GE Amsterdam (Netherlands); Brown, E. F. [Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824 (United States); Cackett, E. M. [Department of Physics and Astronomy, Wayne State University, 666 W. Hancock St, Detroit, MI 48201 (United States); Homan, J. [Massachusetts Institute of Technology, Kavli Institute for Astrophysics and Space Research, Cambridge, MA 02139 (United States); Heinke, C. O.; Sivakoff, G. R. [Department of Physics, University of Alberta, 4-183 CCIS, Edmonton, AB T6G 2E1 (Canada); Pooley, D., E-mail: degenaar@umich.edu [Department of Physics, Sam Houston State University, Huntsville, TX (United States)

    2013-09-20

    The transient neutron star low-mass X-ray binary and 11 Hz X-ray pulsar IGR J17480-2446 in the globular cluster Terzan 5 exhibited an 11 week accretion outburst in 2010. Chandra observations performed within five months after the end of the outburst revealed evidence that the crust of the neutron star became substantially heated during the accretion episode and was subsequently cooling in quiescence. This provides the rare opportunity to probe the structure and composition of the crust. Here, we report on new Chandra observations of Terzan 5 that extend the monitoring to ≅2.2 yr into quiescence. We find that the thermal flux and neutron star temperature have continued to decrease, but remain significantly above the values that were measured before the 2010 accretion phase. This suggests that the crust has not thermally relaxed yet, and may continue to cool. Such behavior is difficult to explain within our current understanding of heating and cooling of transiently accreting neutron stars. Alternatively, the quiescent emission may have settled at a higher observed equilibrium level (for the same interior temperature), in which case the neutron star crust may have fully cooled.

  4. Continued Neutron Star Crust Cooling of the 11 Hz X-Ray Pulsar in Terzan 5: A Challenge to Heating and Cooling Models?

    CERN Document Server

    Degenaar, N; Brown, E F; Altamirano, D; Cackett, E M; Fridriksson, J; Homan, J; Heinke, C O; Miller, J M; Pooley, D; Sivakoff, G R

    2013-01-01

    The transient neutron star low-mass X-ray binary and 11 Hz X-ray pulsar IGR J17480-2446 in the globular cluster Terzan 5 exhibited an 11-week accretion outburst in 2010. Chandra observations performed within five months after the end of the outburst revealed evidence that the crust of the neutron star became substantially heated during the accretion episode and was subsequently cooling in quiescence. This provides the rare opportunity to probe the structure and composition of the crust. Here, we report on new Chandra observations of Terzan 5 that extend the monitoring to ~2.2 yr into quiescence. We find that the thermal flux and neutron star temperature have continued to decrease, but remain significantly above the values that were measured before the 2010 accretion phase. This suggests that the crust has not thermally relaxed yet, and may continue to cool. Such behavior is difficult to explain within our current understanding of heating and cooling of transiently accreting neutron stars. Alternatively, the q...

  5. X-Ray

    Science.gov (United States)

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

  6. Dental x-rays

    Science.gov (United States)

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

  7. X-Ray Surveys

    CERN Document Server

    Giommi, P; Perri, M

    1998-01-01

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

  8. X-ray Polarimetry

    Science.gov (United States)

    Kallman, T.

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

  9. X-ray photoelectron spectroscopic study of the oxide removal mechanism of GaAs /100/ molecular beam epitaxial substrates in in situ heating

    Science.gov (United States)

    Vasquez, R. P.; Lewis, B. F.; Grunthaner, F. J.

    1983-01-01

    A standard cleaning procedure for GaAs (100) molecular beam epitaxial (MBE) substrates is a chemical treatment with a solution of H2SO4/H2O2/H2O, followed by in situ heating prior to MBE growth. X-ray photoelectron spectroscopic (XPS) studies of the surface following the chemical treatment show that the oxidized As is primarily As(+ 5). Upon heating to low temperatures (less than (350 C) the As(+ 5) oxidizes the substrate to form Ga2O3 and elemental As, and the As(+ 5) is reduced to As(+ 3) in the process. At higher temperatures (500 C), the As(+ 3) and elemental As desorb, while the Ga(+ 3) begins desorbing at about 600 C.

  10. X-ray crystallography

    Science.gov (United States)

    2001-01-01

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

  11. Electron Heating and Cosmic Rays at a Supernova Shock from Chandra X-ray Observations of E0102.2-7219

    CERN Document Server

    Hughes, J P; Decourchelle, A; Hughes, John P.; Rakowski, Cara E.; Decourchelle, Anne

    2000-01-01

    In this Letter we use the unprecedented spatial resolution of the Chandra X-ray Observatory to carry out, for the first time, a measurement of the post-shock electron temperature and proper motion of a young SNR, specifically to address questions about the post-shock partition of energy among electrons, ions, and cosmic rays. The expansion rate, 0.100 +/- 0.025 percent per yr, and inferred age, ~1000 yr, of E0102.2-7219, from a comparison of X-ray observations spanning 20 years, are fully consistent with previous estimates based on studies of high velocity oxygen-rich optical filaments in the remnant. With a radius of 6.4 pc for the blast wave estimated from the Chandra image, our expansion rate implies a blast wave velocity of ~6000 km/s and a range of electron temperatures 2.5 - 45 keV, dependent on the degree of collisionless electron heating. Analysis of the Chandra ACIS spectrum of the immediate post-shock region reveals a thermal plasma with abundances and column density typical of the Small Magellanic ...

  12. X-ray lasers

    CERN Document Server

    Elton, Raymond C

    2012-01-01

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

  13. Bone X-Ray (Radiography)

    Medline Plus

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

  14. New Insights into X-ray Binaries

    CERN Document Server

    Casares, Jorge

    2009-01-01

    X-ray binaries are excellent laboratories to study collapsed objects. On the one hand, transient X-ray binaries contain the best examples of stellar-mass black holes while persistent X-ray binaries mostly harbour accreting neutron stars. The determination of stellar masses in persistent X-ray binaries is usually hampered by the overwhelming luminosity of the X-ray heated accretion disc. However, the discovery of high-excitation emission lines from the irradiated companion star has opened new routes in the study of compact objects. This paper presents novel techniques which exploits these irradiated lines and summarises the dynamical masses obtained for the two populations of collapsed stars: neutron stars and black holes.

  15. X-Rays from Green Pea Analogs

    Science.gov (United States)

    Brorby, Matthew

    2014-09-01

    X-rays may have contributed to the heating and reionization of the IGM in the early universe. High mass X-ray binaries (HMXB) within small, low-metallicity galaxies are expected to be the main source of X-rays at this time. Since studying these high-redshift galaxies is currently impossible, we turn to local analogs that have the same properties the galaxies in the early are expected to have. A number of recent studies have shown an enhanced number of HMXBs in nearby low metallicity galaxies. We propose to observe a sample of metal-deficient luminous compact galaxies (LCG) in order to determine if the X-ray luminosity is enhanced relative to SFR, thereby providing further evidence to the importance of X-rays in the early universe.

  16. Metal-like heat conduction in laser-excited InSb probed by picosecond time-resolved x-ray diffraction

    Science.gov (United States)

    Sondhauss, P.; Synnergren, O.; Hansen, T. N.; Canton, S. E.; Enquist, H.; Srivastava, A.; Larsson, J.

    2008-09-01

    A semiconductor (InSb) showed transient metal-like heat conduction after excitation of a dense electron-hole plasma via short and intense light pulses. A related ultrafast strain relaxation was detected using picosecond time-resolved x-ray diffraction. The deduced heat conduction was, by a factor of 30, larger than the lattice contribution. The anomalously high heat conduction can be explained once the contribution from the degenerate photocarrier plasma is taken into account. The magnitude of the effect could provide the means for guiding heat in semiconductor nanostructures. In the course of this work, a quantitative model for the carrier dynamics in laser-irradiated semiconductors has been developed, which does not rely on any adjustable parameters or ad hoc assumptions. The model includes various light absorption processes (interband, free carrier, two photon, and dynamical Burstein-Moss shifts), ambipolar diffusion, energy transport (heat and chemical potential), electrothermal effects, Auger recombination, collisional excitation, and scattering (elastic and inelastic). The model accounts for arbitrary degrees of degeneracy.

  17. Bone x-ray

    Science.gov (United States)

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

  18. Hand x-ray

    Science.gov (United States)

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

  19. Pelvis x-ray

    Science.gov (United States)

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

  20. Chest X-Ray

    Medline Plus

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

  1. Chest X-Ray

    Medline Plus

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

  2. Chest X-Ray

    Medline Plus

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

  3. X-ray - skeleton

    Science.gov (United States)

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

  4. X-Ray Diffraction.

    Science.gov (United States)

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

    1980-01-01

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

  5. Chest X-Ray

    Medline Plus

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

  6. X-Ray Diffraction.

    Science.gov (United States)

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

    1980-01-01

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

  7. Chest X-Ray

    Medline Plus

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

  8. Chest X-Ray

    Medline Plus

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

  9. THE WATER VAPOR SPECTRUM OF APM 08279+5255: X-RAY HEATING AND INFRARED PUMPING OVER HUNDREDS OF PARSECS

    Energy Technology Data Exchange (ETDEWEB)

    Bradford, C. M.; Bock, J. J.; Naylor, B. J.; Nguyen, H. T.; Zmuidzinas, J. [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States); Bolatto, A. D. [Department of Astronomy, University of Maryland, College Park, MD 20742-2421 (United States); Maloney, P. R.; Aguirre, J. E.; Glenn, J.; Kamenetzky, J. [Center for Astrophysics and Space Astronomy, University of Colorado, Boulder, CO 80303 (United States); Lupu, R.; Scott, K. [Department of Physics, University of Pennsylvania, Philadelphia, PA 19104 (United States); Matsuhara, H. [Institute for Space and Astronautical Science, Japan Aerospace and Exploration Agency, 3-1-1 Yoshinodai, Chuo-ku, Sagamihara 252-5210 (Japan); Murphy, E. J. [Observatories of the Carnegie Institution for Science, 813 Santa Barbara Street, Pasadena, CA 91101 (United States)

    2011-11-10

    We present the rest-frame 200-320 {mu}m spectrum of the z = 3.91 quasar APM 08279+5255, obtained with Z-Spec at the Caltech Submillimeter Observatory. In addition to the J = 8 {yields} 7 to J = 13 {yields} 12 CO rotational transitions which dominate the CO cooling, we find six transitions of water originating at energy levels ranging up to 643 K. Most are first detections at high redshift, and we have confirmed one transition with CARMA. The CO cooling is well described by our X-ray dominated region (XDR) model, assuming L{sub 1-100keV} {approx} 1 Multiplication-Sign 10{sup 46} erg s{sup -1}, and that the gas is distributed over a 550-pc size scale, as per the now-favored {mu} = 4 lensing model. The total observed cooling in water corresponds to 6.5 Multiplication-Sign 10{sup 9} L{sub Sun }, comparable to that of CO. We compare the water spectrum with that of Mrk 231, finding that the intensity ratios among the high-lying lines are similar, but with a total luminosity scaled up by a factor of {approx}50. Using this scaling, we estimate an average water abundance relative to H{sub 2} of 1.4 Multiplication-Sign 10{sup -7}, a good match to the prediction of the chemical network in the XDR model. As with Mrk 231, the high-lying water transitions are excited radiatively via absorption in the rest-frame far-infrared, and we show that the powerful dust continuum in APM 08279+5255 is more than sufficient to pump this massive reservoir of warm water vapor.

  10. X-raying clumped stellar winds

    CERN Document Server

    Oskinova, L M; Feldmeier, A

    2008-01-01

    X-ray spectroscopy is a sensitive probe of stellar winds. X-rays originate from optically thin shock-heated plasma deep inside the wind and propagate outwards throughout absorbing cool material. Recent analyses of the line ratios from He-like ions in the X-ray spectra of O-stars highlighted problems with this general paradigm: the measured line ratios of highest ions are consistent with the location of the hottest X-ray emitting plasma very close to the base of the wind, perhaps indicating the presence of a corona, while measurements from lower ions conform with the wind-embedded shock model. Generally, to correctly model the emerging X-ray spectra, a detailed knowledge of the cool wind opacities based on stellar atmosphere models is prerequisite. A nearly grey stellar wind opacity for the X-rays is deduced from the analyses of high-resolution X-ray spectra. This indicates that the stellar winds are strongly clumped. Furthermore, the nearly symmetric shape of X-ray emission line profiles can be explained if t...

  11. Bone X-Ray (Radiography)

    Medline Plus

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

  12. Bone X-Ray (Radiography)

    Medline Plus

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

  13. Bone X-Ray (Radiography)

    Medline Plus

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

  14. Bone X-Ray (Radiography)

    Medline Plus

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

  15. Bone X-Ray (Radiography)

    Medline Plus

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

  16. 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

  17. Measurement of quasi-ballistic heat transport across nanoscale interfaces using ultrafast coherent soft x-ray beams

    Energy Technology Data Exchange (ETDEWEB)

    Siemens, M.; Li, Q.; Yang, R.; Nelson, K.; Anderson, E.; Murnane, M.; Kapteyn, H.

    2009-03-02

    Understanding heat transport on nanoscale dimensions is important for fundamental advances in nanoscience, as well as for practical applications such as thermal management in nano-electronics, thermoelectric devices, photovoltaics, nanomanufacturing, as well as nanoparticle thermal therapy. Here we report the first time-resolved measurements of heat transport across nanostructured interfaces. We observe the transition from a diffusive to a ballistic thermal transport regime, with a corresponding increase in the interface resistivity for line widths smaller than the phonon mean free path in the substrate. Resistivities more than three times higher than the bulk value are measured for the smallest line widths of 65 nm. Our findings are relevant to the modeling and design of heat transport in nanoscale engineered systems, including nanoelectronics, photovoltaics and thermoelectric devices.

  18. X-ray Pulsars

    CERN Document Server

    Walter, Roland

    2016-01-01

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

  19. New limits on 21 cm epoch of reionization from paper-32 consistent with an x-ray heated intergalactic medium at z = 7.7

    Energy Technology Data Exchange (ETDEWEB)

    Parsons, Aaron R.; Liu, Adrian; Ali, Zaki S.; Pober, Jonathan C. [Astronomy Department, University of California, Berkeley, CA (United States); Aguirre, James E.; Moore, David F. [Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA (United States); Bradley, Richard F. [Department of Electrical and Computer Engineering, University of Virginia, Charlottesville, VA (United States); Carilli, Chris L. [National Radio Astronomy Observatory, Socorro, NM (United States); DeBoer, David R.; Dexter, Matthew R.; MacMahon, David H. E. [Radio Astronomy Laboratory, University of California, Berkeley, CA (United States); Gugliucci, Nicole E. [Department of Astronomy, University of Virginia, Charlottesville, VA (United States); Jacobs, Daniel C. [School of Earth and Space Exploration, Arizona State University, Tempe, AZ (United States); Klima, Pat [National Radio Astronomy Observatory, Charlottesville, VA (United States); Manley, Jason R.; Walbrugh, William P. [Square Kilometer Array, South Africa Project, Cape Town (South Africa); Stefan, Irina I. [Cavendish Laboratory, Cambridge (United Kingdom)

    2014-06-20

    We present new constraints on the 21 cm Epoch of Reionization (EoR) power spectrum derived from three months of observing with a 32 antenna, dual-polarization deployment of the Donald C. Backer Precision Array for Probing the Epoch of Reionization in South Africa. In this paper, we demonstrate the efficacy of the delay-spectrum approach to avoiding foregrounds, achieving over eight orders of magnitude of foreground suppression (in mK{sup 2}). Combining this approach with a procedure for removing off-diagonal covariances arising from instrumental systematics, we achieve a best 2σ upper limit of (41 mK){sup 2} for k = 0.27 h Mpc{sup –1} at z = 7.7. This limit falls within an order of magnitude of the brighter predictions of the expected 21 cm EoR signal level. Using the upper limits set by these measurements, we generate new constraints on the brightness temperature of 21 cm emission in neutral regions for various reionization models. We show that for several ionization scenarios, our measurements are inconsistent with cold reionization. That is, heating of the neutral intergalactic medium (IGM) is necessary to remain consistent with the constraints we report. Hence, we have suggestive evidence that by z = 7.7, the H I has been warmed from its cold primordial state, probably by X-rays from high-mass X-ray binaries or miniquasars. The strength of this evidence depends on the ionization state of the IGM, which we are not yet able to constrain. This result is consistent with standard predictions for how reionization might have proceeded.

  20. A water-cooled x-ray monochromator for using off-axis undulator beam.

    Energy Technology Data Exchange (ETDEWEB)

    Khounsary, A.; Maser, J.

    2000-12-11

    Undulator beamlines at third-generation synchrotrons x-ray sources are designed to use the high-brilliance radiation that is contained in the central cone of the generated x-ray beams. The rest of the x-ray beam is often unused. Moreover, in some cases, such as in the zone-plate-based microfocusing beamlines, only a small part of the central radiation cone around the optical axis is used. In this paper, a side-station branch line at the Advanced Photon Source that takes advantage of some of the unused off-axis photons in a microfocusing x-ray beamline is described. Detailed information on the design and analysis of a high-heat-load water-cooled monochromator developed for this beamline is provided.

  1. X-Ray Protection

    Science.gov (United States)

    1955-01-01

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

  2. X-ray Reflection

    Science.gov (United States)

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

    2010-12-01

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

  3. Implosion dynamics and x-ray generation in small-diameter wire-array Z pinches.

    Science.gov (United States)

    Ivanov, V V; Sotnikov, V I; Kindel, J M; Hakel, P; Mancini, R C; Astanovitskiy, A L; Haboub, A; Altemara, S D; Shevelko, A P; Kazakov, E D; Sasorov, P V

    2009-05-01

    It is known from experiments that the radiated x-ray energy appears to exceed the calculated implosion kinetic energy and Spitzer resistive heating [C. Deeney, Phys. Rev. A 44, 6762 (1991)] but possible mechanisms of the enhanced x-ray production are still being discussed. Enhanced plasma heating in small-diameter wire arrays with decreased calculated kinetic energy was investigated, and a review of experiments with cylindrical arrays of 1-16 mm in diameter on the 1 MA Zebra generator is presented in this paper. The implosion and x-ray generation in cylindrical wire arrays with different diameters were compared to find a transition from a regime where thermalization of the kinetic energy is the prevailing heating mechanism to regimes with other dominant mechanisms of plasma heating. Loads of 3-8 mm in diameter generate the highest x-ray power at the Zebra generator. The x-ray power falls in 1-2 mm loads which can be linked to the lower efficiency of plasma heating with the lack of kinetic energy. The electron temperature and density of the pinches also depend on the array diameter. In small-diameter arrays, 1-3 mm in diameter, ablating plasma accumulates in the inner volume much faster than in loads of 12-16 mm in diameter. Correlated bubblelike implosions were observed with multiframe shadowgraphy. Investigation of energy balance provides evidence for mechanisms of nonkinetic plasma heating in Z pinches. Formation and evolution of bright spots in Z pinches were studied with a time-gated pinhole camera. A comparison of x-ray images with shadowgrams shows that implosion bubbles can initiate bright spots in the pinch. Features of the implosions in small-diameter wire arrays are discussed to identify mechanisms of energy dissipation.

  4. Panoramic Dental X-Ray

    Science.gov (United States)

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

  5. X-ray scattering from dense plasmas

    Energy Technology Data Exchange (ETDEWEB)

    McSherry, D.J

    2000-09-01

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

  6. X-ray scattering from dense plasmas

    Science.gov (United States)

    McSherry, Declan Joseph

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

  7. Analysis on explosive welded Al/Mg plates in as-received state and after heat treatment using the in situ high-energy X-ray diffraction

    Science.gov (United States)

    Zhou, Qiang; Chen, Pengwan; Nie, Zhihua; Lan, Yazhu

    2015-06-01

    The synchrotron-based HEXRD method has a much better angular resolution in the reciprocal space than neutron or traditional laboratory XRD, which creates an opportunity that could precisely study the crystal structure and parameter from the XRD pattern. Due to the high penetration depth of high-energy X-ray, the micro-strain and phase distribution could be determined precisely. In this work, the explosive welded 2024 Al/AZ31 Mg plates, both in as-received state and after heat treatment, were investigated by HEXRD method. The XRD patterns were taken shot-by-shot, going from Al to Mg with step width of 0.1mm. The micro-strain, phase distribution and grain size of each step were estimated and analyzed within the general mechanism of explosive welding. It is interesting to find that the intense texture observed in both cladded and base materials disappeared at the welded interface. Residual stress, which was obviously detected at the interface for the as-received sample, was eliminated after heat treatment. For the as-received sample, the strain of Mg along the path from interface to free surface was different for different Azimuth angle and different crystal orientation; but such variations didn't occur for Al.

  8. Effect of Heat Treatment on Electrical Properties and Charge Collection Efficiency of X-Ray Sensors Based on Chrome-Compensated Gallium Arsenide

    Science.gov (United States)

    Zarubin, A. N.; Kolesnikova, I. I.; Lozinskaya, A. D.; Novikov, V. A.; Skakunov, M. S.; Tolbanov, O. P.; Tyazhev, A. V.; Shemeryankina, A. V.

    2016-06-01

    We present the results of experimental studies of the dependences of the specific resistance, charge collection efficiency, product of the mobility on the lifetime (μ×τ)n, and current-voltage characteristics on the heat treatment regimes of X-ray Me-GaAs:Cr-Me-sensors. Experimental samples were the pad-sensors with the area of 0.1-0.25 cm2 and sensitive-layer thickness in the range of 400-500 μm. The values of (μ×τ)n were evaluated by measuring the dependence of the charge collection efficiency on the bias voltage when exposed to gamma rays from the source of 241Am. It is shown that heat treatment in the temperature range 200-500°C does not lead to a significant degradation of properties of Me-GaAs:Cr-Me-sensors and can be used in the manufacturing technology of matrix detectors of ionizing radiation.

  9. X-Ray Background from Early Binaries

    Science.gov (United States)

    Kohler, Susanna

    2016-11-01

    observed X-ray energy (and the total X-ray background is given by the sum of the curves). The two panels show results from two different calculation methods. [Xu et al. 2016]Xu and collaborators have now attempted to model to the impact of this X-ray production from Pop III binaries on the intergalactic medium and determine how much it could have contributed to reionization and the diffuse X-ray background we observe today.Generating a BackgroundThe authorsestimated the X-ray luminosities from Pop III binaries using the results of a series of galaxy-formation simulations, beginning at a redshift of z 25 and evolving up to z = 7.6. They then used these luminosities to calculate the resulting X-ray background.Xu and collaborators find that Pop III binaries can produce significant X-ray radiation throughout the period of reionization, and this radiation builds up gradually into an X-ray background. The team shows that X-rays from Pop III binaries might actually dominate more commonly assumed sources of the X-ray background at high redshifts (such as active galactic nuclei), and this radiation isstrong enough to heat the intergalactic medium to 1000K and ionize a few percent of the neutral hydrogen.If Pop III binaries are indeed this large of a contributor to the X-ray background and to the local and global heating of the intergalactic medium, then its important that we follow up with more detailed modeling to understand what this means for our interpretation of cosmological observations.CitationHao Xu et al 2016 ApJL 832 L5. doi:10.3847/2041-8205/832/1/L5

  10. Chest X-Ray

    Medline Plus

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

  11. X-ray Emission from Solar Flares

    Indian Academy of Sciences (India)

    Rajmal Jain; Malini Aggarwal; Raghunandan Sharma

    2008-03-01

    Solar X-ray Spectrometer (SOXS), the first space-borne solar astronomy experiment of India was designed to improve our current understanding of X-ray emission from the Sun in general and solar flares in particular. SOXS mission is composed of two solid state detectors, viz., Si and CZT semiconductors capable of observing the full disk Sun in X-ray energy range of 4–56 keV. The X-ray spectra of solar flares obtained by the Si detector in the 4–25 keV range show evidence of Fe and Fe/Ni line emission and multi-thermal plasma. The evolution of the break energy point that separates the thermal and non-thermal processes reveals increase with increasing flare plasma temperature. Small scale flare activities observed by both the detectors are found to be suitable to heat the active region corona; however their location appears to be in the transition region.

  12. High Heat-Load Slits for the PLS Multipole Wiggler

    CERN Document Server

    Gil, Kyehwan; Kim, Young-Chan; Lee, Heung-Soo; Wha Chung, Chin

    2005-01-01

    The HFMX (High Flux Macromolecular X-ray crystallography) beamline under commissioning at Pohang Accelerator Laboratory uses beam from a multipole wiggler for MAD experiment. Two horizontal and vertical slits relevant to high heat load are installed at its front-end. In order to treat high heat load and to reduce beam scattering, the horizontal slit has two glidcop blocks with 10° of vertical inclination and its tungsten blades defining beam size are bolted on backsides of both blocks. The blocks of the slit are adjusted on fixed slides by two actuating bars, respectively. Water through channels machined along the actuating bars cool down the heat load of both blocks. The vertical slit has the same structure as the horizontal slit except its installation direction and angle of vertical inclination. The installed slits show stable operation performance and no alignment for the blocks is required by virtue of a pair of blocks translating on slides. The cooling performance of two slits is also shown to ...

  13. Observations of Ferrite/Austenite Transformations in the Heat Affected Zone of 2205 Duplex Stainless Steel Spot Welds Using Time Resolved X-Ray Diffraction

    Energy Technology Data Exchange (ETDEWEB)

    Palmer, T; Elmer, J; Babu, S

    2003-10-29

    Time Resolved X-Ray Diffraction (TRXRD) measurements are made in the Heat Affected Zone (HAZ) of 2205 Duplex Stainless Steel (DSS) spot welds. Both the {gamma} {yields} {delta} and {delta} {yields} {gamma} transformations are monitored as a function of time during the rapid spot weld heating and cooling cycles. These observations are then correlated with calculated thermal cycles. Where the peak temperatures are highest ({approx}1342 C), the {gamma} {yields} {delta} transformation proceeds to completion, leaving a ferritic microstructure at the end of heating. With lower peak temperatures, the {gamma} {yields} {delta} transformation proceeds to only partial completion, resulting in a microstructure containing both transformed and untransformed austenite. Further analyses of the individual diffraction patterns show shifts in the peak positions and peak widths as a function of both time and temperature. In addition, these changes in the peak characteristics are correlated with measured changes in the ferrite volume fraction. Such changes in the peak positions and widths during the {gamma} {yields} {delta} transformation provide an indication of changes occurring in each phase. These changes in peak properties can be correlated with the diffusion of nitrogen and other substitutional alloying elements, which are recognized as the primary mechanisms for this transformation. Upon cooling, the {delta} {yields} {gamma} transformation is observed to proceed from both the completely and partially transformed microstructural regions in the TRXRD data. An examination of the resulting microstructures confirms the TRXRD observation as the evidence shows that austenite both nucleates and grows from the ferritic microstructure at locations closest to the fusion zone boundary and grows from untransformed austenite grains at locations further from this boundary.

  14. X-Ray Astronomy

    Science.gov (United States)

    Wu, S. T.

    2000-01-01

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

  15. X-ray lithography masking

    Science.gov (United States)

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

    1998-01-01

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

  16. Development of a laser-based heating system for in situ synchrotron-based X-ray tomographic microscopy.

    Science.gov (United States)

    Fife, Julie L; Rappaz, Michel; Pistone, Mattia; Celcer, Tine; Mikuljan, Gordan; Stampanoni, Marco

    2012-05-01

    Understanding the formation of materials at elevated temperatures is critical for determining their final properties. Synchrotron-based X-ray tomographic microscopy is an ideal technique for studying such processes because high spatial and temporal resolutions are easily achieved and the technique is non-destructive, meaning additional analyses can take place after data collection. To exploit the state-of-the-art capabilities at the tomographic microscopy and coherent radiology experiments (TOMCAT) beamline of the Swiss Light Source, a general-use moderate-to-high-temperature furnace has been developed. Powered by two diode lasers, it provides controlled localized heating, from 673 to 1973 K, to examine many materials systems and their dynamics in real time. The system can also be operated in various thermal modalities. For example, near-isothermal conditions at a given sample location can be achieved with a prescribed time-dependent temperature. This mode is typically used to study isothermal phase transformations; for example, the formation of equiaxed grains in metallic systems or to nucleate and grow bubble foams in silicate melts under conditions that simulate volcanic processes. In another mode, the power of the laser can be fixed and the specimen moved at a constant speed in a user-defined thermal gradient. This is similar to Bridgman solidification, where the thermal gradient and cooling rate control the microstructure formation. This paper details the experimental set-up and provides multiple proofs-of-concept that illustrate the versatility of using this laser-based heating system to explore, in situ, many elevated-temperature phenomena in a variety of materials.

  17. Panoramic Dental X-Ray

    Science.gov (United States)

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

  18. Bone X-Ray (Radiography)

    Medline Plus

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

  19. Bone X-Ray (Radiography)

    Medline Plus

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

  20. Soft X-ray Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Seely, John

    1999-05-20

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

  1. Bone X-Ray (Radiography)

    Medline Plus

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

  2. Bone X-Ray (Radiography)

    Science.gov (United States)

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

  3. Bone X-Ray (Radiography)

    Medline Plus

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

  4. Bone X-Ray (Radiography)

    Medline Plus

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

  5. Bone X-Ray (Radiography)

    Medline Plus

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

  6. Bone X-Ray (Radiography)

    Medline Plus

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

  7. Abdomen X-Ray (Radiography)

    Science.gov (United States)

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

  8. Bone X-Ray (Radiography)

    Medline Plus

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

  9. Bone X-Ray (Radiography)

    Medline Plus

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

  10. Bone X-Ray (Radiography)

    Medline Plus

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

  11. Bone X-Ray (Radiography)

    Medline Plus

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

  12. Bone X-Ray (Radiography)

    Medline Plus

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

  13. Analysis of damage processes in short glass fibre reinforced polyamide under mechanical loading by X-ray refractometry, fracture mechanics and fractography; Analyse der Schaedigungsprozesse in einem kurzglasfaserverstaerkten Polyamid unter mechanischer Belastung mittels Roentgenrefraktometrie, Bruchmechanik und Fraktografie

    Energy Technology Data Exchange (ETDEWEB)

    Guenzel, Stephan

    2013-04-01

    This thesis presents an analysis of the damage behaviour in a short glass fibre reinforced polyamide. The micro cracking is investigated by X-ray refraction technique under various, mechanical in-service loadings. In this context, potentials and limits of X-ray refraction analysis for short glass fibre reinforced polyamides are compiled. In particular the influence of fibre orientation and the influence of damage mechanisms are examined according to the X-ray refraction analysis and its interpretation. The method offers a quantitative and phenomenological based characterisation of micro crack damage. For the investigated material micro crack damage emerges as fibre matrix debonding and matrix micro cracking. The state of damage correlates with a nonlinear strain portion in a linear manner and depends on the kind of loading. Absorption of moisture in the material may influence significantly the micro crack damage behaviour. Damage of micro cracking appears preferentially under tension. The macro damage due to propagation of a single crack is characterised in an automated test setup, considering the fibre orientation and content of moisture. Based on the findings an empirical assessment approach is developed. The investigations of the micro and macro damage behaviour are accompanied by fractography, in order to support the model assumptions according to damage and fracture mechanisms.

  14. X-Ray Exam: Hip

    Science.gov (United States)

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

  15. X-Ray Exam: Finger

    Science.gov (United States)

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

  16. X-Ray Exam: Foot

    Science.gov (United States)

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

  17. X-Ray Exam: Wrist

    Science.gov (United States)

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

  18. X-Ray Exam: Ankle

    Science.gov (United States)

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

  19. X-Ray Exam: Pelvis

    Science.gov (United States)

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

  20. X-Ray Exam: Forearm

    Science.gov (United States)

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

  1. X-ray selected BALQSOs

    CERN Document Server

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

    2016-01-01

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

  2. X-ray Crystallography Facility

    Science.gov (United States)

    2000-01-01

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

  3. APS high heat load monochromator

    Energy Technology Data Exchange (ETDEWEB)

    Lee, W.K.; Mills, D.

    1993-02-01

    This document contains the design specifications of the APS high heat load (HHL) monochromator and associated accessories as of February 1993. It should be noted that work is continuing on many parts of the monochromator including the mechanical design, crystal cooling designs, etc. Where appropriate, we have tried to add supporting documentation, references to published papers, and calculations from which we based our decisions. The underlying philosophy behind performance specifications of this monochromator was to fabricate a device that would be useful to as many APS users as possible, that is, the design should be as generic as possible. In other words, we believe that this design will be capable of operating on both bending magnet and ID beamlines (with the appropriate changes to the cooling and crystals) with both flat and inclined crystal geometries and with a variety of coolants. It was strongly felt that this monochromator should have good energy scanning capabilities over the classical energy range of about 4 to 20 keywith Si (111) crystals. For this reason, a design incorporating one rotation stage to drive both the first and second crystals was considered most promising. Separate rotary stages for the first and second crystals can sometimes provide more flexibility in their capacities to carry heavy loads (for heavily cooled first crystals or sagittal benders of second crystals), but their tuning capabilities were considered inferior to the single axis approach.

  4. SMM x ray polychromator

    Science.gov (United States)

    Saba, J. L. R.

    1993-01-01

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

  5. X-ray today

    Energy Technology Data Exchange (ETDEWEB)

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

    2001-09-01

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

  6. X-ray lithography source

    Science.gov (United States)

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

    1991-01-01

    A high-intensity, inexpensive X-ray source for X-ray lithography for the production of integrated circuits. Foil stacks are bombarded with a high-energy electron beam of 25 to 250 MeV to produce a flux of soft X-rays of 500 eV to 3 keV. Methods of increasing the total X-ray power and making the cross section of the X-ray beam uniform are described. Methods of obtaining the desired X-ray-beam field size, optimum frequency spectrum and elminating the neutron flux are all described. A method of obtaining a plurality of station operation is also described which makes the process more efficient and economical. The satisfying of these issues makes transition radiation an exellent moderate-priced X-ray source for lithography.

  7. The accretion-heated crust of the transiently accreting 11-Hz X-ray pulsar in the globular cluster Terzan 5

    NARCIS (Netherlands)

    N. Degenaar; R. Wijnands

    2011-01-01

    We report on a Chandra Director’s Discretionary Time observation of the globular cluster Terzan 5, carried out ∼7 weeks after the cessation of the 2010 outburst of the newly discovered transiently accreting 11-Hz X-ray pulsar. We detect a thermal spectrum that can be fitted with a neutron star atmos

  8. Fast and Furious: Shock Heated Gas as the Origin of Spatially Resolved Hard X-ray Emission in the Central 5 kpc of the Galaxy Merger NGC 6240

    CERN Document Server

    Wang, Junfeng; Fabbiano, Giuseppina; Karovska, Margarita; Elvis, Martin; Pellegrini, Silvia; Max, Claire; Risaliti, Guido; U, Vivian; Zezas, Andreas

    2013-01-01

    We have obtained a deep, sub-arcsecond resolution X-ray image of the nuclear region of the luminous galaxy merger NGC 6240 with Chandra, which resolves the X-ray emission from the pair of active nuclei and the diffuse hot gas in great detail. We detect extended hard X-ray emission from kT~6 keV (~70 million K) hot gas over a spatial scale of 5 kpc, indicating the presence of fast shocks with velocity of ~2200 km/s. For the first time we obtain the spatial distribution of this highly ionized gas emitting FeXXV, which shows a remarkable correspondence to the large scale morphology of H_2(1-0) S(1) line emission and H\\alpha filaments. Propagation of fast shocks originated in the starburst driven wind into the ambient dense gas can account for this morphological correspondence. With an observed L(0.5-8 keV)=5.3E+41 erg/s, the diffuse hard X-ray emission is 100 times more luminous than that observed in the classic starburst galaxy M82. Assuming a filling factor of 1% for the 70 MK temperature gas, we estimate its ...

  9. Preconcentration and determination of Ce, La and Pr by x-ray fluorescence analysis, using amberlite XAD resins loaded with 8-quinolinol and 2-(2-(5 chloropyridylazo)-5-dimethylamino)-phenol

    Energy Technology Data Exchange (ETDEWEB)

    Masi, A.N.; Olsina, R.A. (National Univ. of San Luis (Argentina). Dept. of Analytical Chemistry)

    1993-06-01

    8-Quinolinol (oxine) and 2-(2-(5 chloropyridylazo)-5-dimethylamino)-phenol (5ClDMPAP) were immobilized on the non ionic sorbents Amberlite XAD-4 and XAD-7. These loaded resins were used for the preconcentration of Ce, La and Pr. High preconcentration factors were obtained in each case. After the retention of these rare earths, the resins were measured as thin films by X-ray fluorescence spectrometry. Up to 50 ppm of REEs can be retained on these thin films. (Author).

  10. X-Ray Attenuation Cell

    Energy Technology Data Exchange (ETDEWEB)

    Ryutov, D.; Toor, A.

    2000-03-03

    To minimize the pulse-to-pulse variation, the LCLS FEL must operate at saturation, i.e. 10 orders of magnitude brighter spectral brilliance than 3rd-generation light sources. At this intensity, ultra-high vacuums and windowless transport are required. Many of the experiments, however, will need to be conducted at a much lower intensity thereby requiring a reliable means to reduce the x-ray intensity by many orders of magnitude without increasing the pulse-to-pulse variation. In this report we consider a possible solution for controlled attenuation of the LCLS x-ray radiation. We suggest using for this purpose a windowless gas-filled cell with the differential pumping. Although this scheme is easily realizable in principle, it has to be demonstrated that the attenuator can be made short enough to be practical and that the gas loads delivered to the vacuum line of sight (LOS) are acceptable. We are not going to present a final, optimized design. Instead, we will provide a preliminary analysis showing that the whole concept is robust and is worth further study. The spatial structure of the LCLS x-ray pulse at the location of the attenuator is shown in Fig. 1. The central high-intensity component, due to the FEL, has a FWHM of {approx}100 {micro}m. A second component, due to the undulator's broad band spontaneous radiation is seen as a much lower intensity ''halo'' with a FWHM of 1 mm. We discuss two versions of the attenuation cell. The first is directed towards a controlled attenuation of the FEL up to the 4 orders of magnitude in the intensity, with the spontaneous radiation halo being eliminated by collimators. In the second version, the spontaneous radiation is not sacrificed but the FEL component (as well as the first harmonic of the spontaneous radiation) gets attenuated by a more modest factor up to 100. We will make all the estimates assuming that the gas used in the attenuator is Xenon and that the energy of the FEL is 8.25 keV. At

  11. Experimental demonstration of benchtop x-ray fluorescence computed tomography (XFCT) of gold nanoparticle-loaded objects using lead- and tin-filtered polychromatic cone-beams.

    Science.gov (United States)

    Jones, Bernard L; Manohar, Nivedh; Reynoso, Francisco; Karellas, Andrew; Cho, Sang Hyun

    2012-12-07

    This report presents the first experimental demonstration, to our knowledge, of benchtop polychromatic cone-beam x-ray fluorescence computed tomography (XFCT) for a simultaneous determination of the spatial distribution and amount of gold nanoparticles (GNPs) within small-animal-sized objects. The current benchtop experimental setup successfully produced XFCT images accurately showing the regions containing small amount of GNPs (on the order of 0.1 mg) within a 3 cm diameter plastic phantom. In particular, the performance of the current XFCT setup was improved remarkably (e.g., at least a factor of 3 reduction in XFCT scan time) using a tin-filtered polychromatic beam in comparison with a lead-filtered beam. The results of this study strongly suggest that the current benchtop XFCT configuration can be made practical with a few modifications such as the deployment of array detectors, while meeting realistic constraints on x-ray dose, scan time and image resolution for routine pre-clinical in vivo imaging with GNPs.

  12. Topological X-Rays Revisited

    Science.gov (United States)

    Lynch, Mark

    2012-01-01

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

  13. X-ray instrumentation for SR beamlines

    CERN Document Server

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

    2000-01-01

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

  14. X-ray Fluorescence Sectioning

    CERN Document Server

    Cong, Wenxiang

    2012-01-01

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

  15. Soft X-ray optics

    CERN Document Server

    Spiller, Eberhard A

    1993-01-01

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

  16. X-ray Absorption Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Yano, Junko; Yachandra, Vittal K.

    2009-07-09

    This review gives a brief description of the theory and application of X-ray absorption spectroscopy, both X-ray absorption near edge structure (XANES) and extended X-ray absorption fine structure (EXAFS), especially, pertaining to photosynthesis. The advantages and limitations of the methods are discussed. Recent advances in extended EXAFS and polarized EXAFS using oriented membranes and single crystals are explained. Developments in theory in understanding the XANES spectra are described. The application of X-ray absorption spectroscopy to the study of the Mn4Ca cluster in Photosystem II is presented.

  17. Fast and Furious: Shock heated gas as the origin of spatially resolved hard X-ray emission in the central 5 kpc of the galaxy merger NGC 6240

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Junfeng; Nardini, Emanuele; Fabbiano, Giuseppina; Karovska, Margarita; Elvis, Martin; Risaliti, Guido; Zezas, Andreas [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Pellegrini, Silvia [Dipartimento di Astronomia, Universitá di Bologna, Via Ranzani 1, I-40127 Bologna (Italy); Max, Claire [Center for Adaptive Optics, University of California, 1156 High Street, Santa Cruz, CA 95064 (United States); U, Vivian, E-mail: jfwang@northwestern.edu [Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822 (United States)

    2014-01-20

    We have obtained a deep, subarcsecond resolution X-ray image of the nuclear region of the luminous galaxy merger NGC 6240 with Chandra, which resolves the X-ray emission from the pair of active nuclei and the diffuse hot gas in great detail. We detect extended hard X-ray emission from kT ∼ 6 keV (∼70 MK) hot gas over a spatial scale of 5 kpc, indicating the presence of fast shocks with a velocity of ∼2200 km s{sup –1}. For the first time, we obtain the spatial distribution of this highly ionized gas emitting Fe XXV, which shows a remarkable correspondence to the large-scale morphology of H{sub 2}(1-0) S(1) line emission and Hα filaments. Propagation of fast shocks originating in the starburst-driven wind into the ambient dense gas can account for this morphological correspondence. With an observed L {sub 0.5-8} {sub keV} = 5.3 × 10{sup 41} erg s{sup –1}, the diffuse hard X-ray emission is ∼100 times more luminous than that observed in the classic starburst galaxy M82. Assuming a filling factor of 1% for the 70 MK temperature gas, we estimate its total mass (M {sub hot} = 1.8 × 10{sup 8} M {sub ☉}) and thermal energy (E {sub th} = 6.5 × 10{sup 57} erg). The total iron mass in the highly ionized plasma is M {sub Fe} = 4.6 × 10{sup 5} M {sub ☉}. Both the energetics and the iron mass in the hot gas are consistent with the expected injection from the supernovae explosion during the starburst that is commensurate with its high star formation rate. No evidence for fluorescent Fe I emission is found in the CO filament connecting the two nuclei.

  18. Bone X-Ray (Radiography)

    Medline Plus

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

  19. Bone X-Ray (Radiography)

    Medline Plus

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

  20. Mass transfer in binary X-ray systems

    Science.gov (United States)

    Mccray, R.; Hatchett, S.

    1975-01-01

    The influence of X-ray heating on gas flows in binary X-ray systems is examined. A simple estimate is obtained for the evaporative wind flux from a stellar atmosphere due to X-ray heating which agrees with numerical calculations by Alme and Wilson (1974) but disagrees with calculations by Arons (1973) and by Basko and Sunyaev (1974) for the Her X-1/HZ Her system. The wind flux is sensitive to the soft X-ray spectrum. The self-excited wind mechanism does not work. Mass transfer in the Hercules system probably occurs by flow of the atmosphere of HZ Her through the gravitational saddle point of the system. The accretion gas stream is probably opaque with atomic density of not less than 10 to the 15th power per cu cm and is confined to a small fraction of 4(pi) steradians. Other binary X-ray systems are briefly discussed.

  1. Supernova remnants: the X-ray perspective

    Science.gov (United States)

    Vink, Jacco

    2012-12-01

    Supernova remnants are beautiful astronomical objects that are also of high scientific interest, because they provide insights into supernova explosion mechanisms, and because they are the likely sources of Galactic cosmic rays. X-ray observations are an important means to study these objects. And in particular the advances made in X-ray imaging spectroscopy over the last two decades has greatly increased our knowledge about supernova remnants. It has made it possible to map the products of fresh nucleosynthesis, and resulted in the identification of regions near shock fronts that emit X-ray synchrotron radiation. Since X-ray synchrotron radiation requires 10-100 TeV electrons, which lose their energies rapidly, the study of X-ray synchrotron radiation has revealed those regions where active and rapid particle acceleration is taking place. In this text all the relevant aspects of X-ray emission from supernova remnants are reviewed and put into the context of supernova explosion properties and the physics and evolution of supernova remnants. The first half of this review has a more tutorial style and discusses the basics of supernova remnant physics and X-ray spectroscopy of the hot plasmas they contain. This includes hydrodynamics, shock heating, thermal conduction, radiation processes, non-equilibrium ionization, He-like ion triplet lines, and cosmic ray acceleration. The second half offers a review of the advances made in field of X-ray spectroscopy of supernova remnants during the last 15 year. This period coincides with the availability of X-ray imaging spectrometers. In addition, I discuss the results of high resolution X-ray spectroscopy with the Chandra and XMM-Newton gratings. Although these instruments are not ideal for studying extended sources, they nevertheless provided interesting results for a limited number of remnants. These results provide a glimpse of what may be achieved with future microcalorimeters that will be available on board future X-ray

  2. Numerical Model for Conduction-Cooled Current Lead Heat Loads

    CERN Document Server

    White, M J; Brueck, H D; 10.1063/1.4706965

    2012-01-01

    Current leads are utilized to deliver electrical power from a room temperature junction mounted on the vacuum vessel to a superconducting magnet located within the vacuum space of a cryostat. There are many types of current leads used at laboratories throughout the world, however, conduction-cooled current leads are often chosen for their simplicity and reliability. Conduction-cooled leads have the advantage of using common materials, have no superconducting/normal state transition, and have no boil-off vapor to collect. The XFEL (X-Ray Free Electron Laser) magnets are operated at 2 K, which makes vapor-cooled current leads impractical due to the sub-atmospheric bath pressure. This paper presents a numerical model for conduction-cooled current lead heat loads. This model takes into account varying material and fluid thermal properties, varying thicknesses along the length of the lead, heat transfer in the circumferential and longitudinal directions, electrical power dissipation, and the effect of thermal inte...

  3. X-ray insights into star and planet formation.

    Science.gov (United States)

    Feigelson, Eric D

    2010-04-20

    Although stars and planets form in cold environments, X-rays are produced in abundance by young stars. This review examines the implications of stellar X-rays for star and planet formation studies, highlighting the contributions of NASA's (National Aeronautics and Space Administration) Chandra X-ray Observatory. Seven topics are covered: X-rays from protostellar outflow shocks, X-rays from the youngest protostars, the stellar initial mass function, the structure of young stellar clusters, the fate of massive stellar winds, X-ray irradiation of protoplanetary disks, and X-ray flare effects on ancient meteorites. Chandra observations of star-forming regions often show dramatic star clusters, powerful magnetic reconnection flares, and parsec-scale diffuse plasma. X-ray selected samples of premain sequence stars significantly advance studies of star cluster formation, the stellar initial mass function, triggered star-formation processes, and protoplanetary disk evolution. Although X-rays themselves may not play a critical role in the physics of star formation, they likely have important effects on protoplanetary disks by heating and ionizing disk gases.

  4. Focusing X-Ray Telescopes

    Science.gov (United States)

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

    2010-01-01

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

  5. X-Ray Tomographic Reconstruction

    Energy Technology Data Exchange (ETDEWEB)

    Bonnie Schmittberger

    2010-08-25

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

  6. X-Ray Diffraction Apparatus

    Science.gov (United States)

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

    1996-01-01

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

  7. Heat Load Estimator for Smoothing Pulsed Heat Loads on Supercritical Helium Loops

    Science.gov (United States)

    Hoa, C.; Lagier, B.; Rousset, B.; Bonnay, P.; Michel, F.

    Superconducting magnets for fusion are subjected to large variations of heat loads due to cycling operation of tokamaks. The cryogenic system shall operate smoothly to extract the pulsed heat loads by circulating supercritical helium into the coils and structures. However the value of the total heat loads and its temporal variation are not known before the plasma scenario starts. A real-time heat load estimator is of interest for the process control of the cryogenic system in order to anticipate the arrival of pulsed heat loads to the refrigerator and finally to optimize the operation of the cryogenic system. The large variation of the thermal loads affects the physical parameters of the supercritical helium loop (pressure, temperature, mass flow) so those signals can be used for calculating instantaneously the loads deposited into the loop. The methodology and algorithm are addressed in the article for estimating the heat load deposition before it reaches the refrigerator. The CEA patented process control has been implemented in a Programmable Logic Controller (PLC) and has been successfully validated on the HELIOS test facility at CEA Grenoble. This heat load estimator is complementary to pulsed load smoothing strategies providing an estimation of the optimized refrigeration power. It can also effectively improve the process control during the transient between different operating modes by adjusting the refrigeration power to the need. This way, the heat load estimator participates to the safe operation of the cryogenic system.

  8. X-ray monitoring optical elements

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-12-27

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

  9. X-ray diagnostics for TFTR

    Energy Technology Data Exchange (ETDEWEB)

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

    1982-12-01

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

  10. X-ray Photoevaporation-starved T Tauri Accretion

    CERN Document Server

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

    2009-01-01

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

  11. Load Management in District Heating Operation

    DEFF Research Database (Denmark)

    Li, Hongwei; Wang, Stephen Jia

    2015-01-01

    heating load can be reduced through building demand side management. The building thermal mass can be used to shift the heating supply under the circumstance without jeopardizing the consumer thermal comfort. In this paper, the multi-agent framework is applied to a simplified building dynamic model...

  12. Semiconductor X-ray detectors

    CERN Document Server

    Lowe, Barrie Glyn

    2014-01-01

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

  13. Design and fabrication of heat resistant multilayers

    Energy Technology Data Exchange (ETDEWEB)

    Thorne, J.M.; Knight, L.V.; Peterson, B.G.; Perkins, R.T.; Gray, K.J.

    1986-01-01

    Many promising applications of multilayer x-ray optical elements subject them to intense radiation. This paper discusses the selection of optimal pairs of materials to resist heat damage and presents simulations of multilayer performance under extreme heat loadings.

  14. Determination of inconsistency of crystal lattice parameters of. gamma. - and. gamma. '-phases of nickel heat resisting alloys by Fourier-analysis of x-ray diffraction reflex profiles

    Energy Technology Data Exchange (ETDEWEB)

    Samojlov, A.I.; Ignatova, I.A.; Krivko, A.I.; Kozlova, V.S.; Dodonova, L.P.

    1983-01-01

    A method is outlined that enables with the use of Fourier-analysis of summary unresolved X-ray diffraction profile of the matrix ..gamma.. and intermetallic ..gamma..' phases of nickel heat resisting alloys of the Ni-Cr-Co-Al-Ti-Nb-W-Mo-V -Hf system, to calculate the location of reflexes of each phase, that is, to determine the periods of their crystal lattices in the alloy (in monolith) directly without electrolytic separation of ..gamma..'-phase. The limits of the method applicability were determined.

  15. Residential Variable-Capacity Heat Pumps Sized to Heating Loads

    Energy Technology Data Exchange (ETDEWEB)

    Munk, Jeffrey D. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Jackson, Roderick K. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Odukomaiya, Adewale [Georgia Inst. of Technology, Atlanta, GA (United States); Gehl, Anthony C. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2014-01-01

    Variable capacity heat pumps are an emerging technology offering significant energy savings potential and improved efficiency. With conventional single-speed systems, it is important to appropriately size heat pumps for the cooling load as over-sizing would result in cycling and insufficient latent capacity required for humidity control. These appropriately sized systems are often under-sized for the heating load and require inefficient supplemental electric resistance heat to meet the heating demand. Variable capacity heat pumps address these shortcomings by providing an opportunity to intentionally size systems for the dominant heating season load without adverse effects of cycling or insufficient dehumidification in the cooling season. This intentionally-sized system could result in significant energy savings in the heating season, as the need for inefficient supplemental electric resistance heat is drastically reduced. This is a continuation of a study evaluating the energy consumption of variable capacity heat pumps installed in two unoccupied research homes in Farragut, a suburb of Knoxville, Tennessee. In this particular study, space conditioning systems are intentionally sized for the heating season loads to provide an opportunity to understand and evaluate the impact this would have on electric resistance heat use and dehumidification. The results and conclusions drawn through this research are valid and specific for portions of the Southeastern and Midwestern United States falling in the mixed-humid climate zone. While other regions in the U.S. do not experience this type of climate, this work provides a basis for, and can help understand the implications of other climate zones on residential space conditioning energy consumption. The data presented here will provide a framework for fine tuning residential building EnergyPlus models that are being developed.

  16. Residential Variable-Capacity Heat Pumps Sized to Heating Loads

    Energy Technology Data Exchange (ETDEWEB)

    Munk, Jeffrey D. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Jackson, Roderick K. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Odukomaiya, Adewale [Georgia Inst. of Technology, Atlanta, GA (United States); Gehl, Anthony C. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2014-01-01

    Variable capacity heat pumps are an emerging technology offering significant energy savings potential and improved efficiency. With conventional single-speed systems, it is important to appropriately size heat pumps for the cooling load as over-sizing would result in cycling and insufficient latent capacity required for humidity control. These appropriately sized systems are often under-sized for the heating load and require inefficient supplemental electric resistance heat to meet the heating demand. Variable capacity heat pumps address these shortcomings by providing an opportunity to intentionally size systems for the dominant heating season load without adverse effects of cycling or insufficient dehumidification in the cooling season. This intentionally-sized system could result in significant energy savings in the heating season, as the need for inefficient supplemental electric resistance heat is drastically reduced. This is a continuation of a study evaluating the energy consumption of variable capacity heat pumps installed in two unoccupied research homes in Farragut, a suburb of Knoxville, Tennessee. In this particular study, space conditioning systems are intentionally sized for the heating season loads to provide an opportunity to understand and evaluate the impact this would have on electric resistance heat use and dehumidification. The results and conclusions drawn through this research are valid and specific for portions of the Southeastern and Midwestern United States falling in the mixed-humid climate zone. While other regions in the U.S. do not experience this type of climate, this work provides a basis for, and can help understand the implications of other climate zones on residential space conditioning energy consumption. The data presented here will provide a framework for fine tuning residential building EnergyPlus models that are being developed.

  17. An X-ray View of Radio Millisecond Pulsars

    CERN Document Server

    Bogdanov, Slavko

    2007-01-01

    In recent years, X-ray observations with Chandra and XMM-Newton have significantly increased our understanding of rotation-powered (radio) millisecond pulsars (MSPs). Deep Chandra studies of several globular clusters have detected X-ray counterparts to a host of MSPs, including 19 in 47 Tuc alone. These surveys have revealed that most MSPs exhibit thermal emission from their heated magnetic polar caps. Realistic models of this thermal X-ray emission have provided important insight into the basic physics of pulsars and neutron stars. In addition, intrabinary shock X-ray radiation observed in ``black-widow'' and peculiar globular cluster ``exchanged'' binary MSPs give interesting insight into MSP winds and relativistic shock. Thus, the X-ray band contains valuable information regarding the basic properties of MSPs that are not accesible by radio timing observations.

  18. Multi-Kilovolt X-Ray Conversion Efficiencies

    Energy Technology Data Exchange (ETDEWEB)

    Back, C A; Davis, J L; Grun, J; Landen, O L; Miller, M C; Suter, L J

    2001-08-23

    X-ray sources in the 3-7 keV energy regime can be produced by laser-irradiating mid- and high-Z gas-filled targets with high-powered lasers. A series of experiments have been performed using underdense targets that are supersonically heated with {approx} 35 kJ of 0.35 {micro}m laser light. These targets were cylindrical Be enclosures that were filled with 1-2 atms of Xe or Ar gas. L-shell x-ray emission is emitted from the plasma and detected by Bragg crystal spectrometers and x-ray diodes. Absolute flux measurements show conversion efficiencies of {approx} 10% in the multi-kilovolt x-ray emission. These sources can be used as bright x-ray backlighters or for material testing.

  19. Bone X-Ray (Radiography)

    Medline Plus

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

  20. Bone X-Ray (Radiography)

    Science.gov (United States)

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

  1. Bone X-Ray (Radiography)

    Medline Plus

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

  2. Bone X-Ray (Radiography)

    Medline Plus

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

  3. Bone X-Ray (Radiography)

    Medline Plus

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

  4. CELESTIAL X-RAY SOURCES.

    Science.gov (United States)

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

  5. Bone X-Ray (Radiography)

    Medline Plus

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

  6. Bone X-Ray (Radiography)

    Medline Plus

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

  7. X-Ray Assembler Data

    Data.gov (United States)

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

  8. Bone X-Ray (Radiography)

    Medline Plus

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

  9. Bone X-Ray (Radiography)

    Medline Plus

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

  10. Bone X-Ray (Radiography)

    Medline Plus

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

  11. Bone X-Ray (Radiography)

    Medline Plus

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

  12. Bone X-Ray (Radiography)

    Medline Plus

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

  13. Bone X-Ray (Radiography)

    Medline Plus

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

  14. Bone X-Ray (Radiography)

    Medline Plus

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

  15. Bone X-Ray (Radiography)

    Medline Plus

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

  16. Bone X-Ray (Radiography)

    Medline Plus

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

  17. Bone X-Ray (Radiography)

    Medline Plus

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

  18. Bone X-Ray (Radiography)

    Medline Plus

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

  19. Bone X-Ray (Radiography)

    Medline Plus

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

  20. Bone X-Ray (Radiography)

    Medline Plus

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

  1. Electromechanical x-ray generator

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-05-03

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

  2. Accelerator x-ray sources

    CERN Document Server

    Talman, Richard

    2007-01-01

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

  3. X-ray fluorescence holography

    CERN Document Server

    Hayashi, K; Takahashi, Y

    2003-01-01

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

  4. X-ray Sensitive Material

    Science.gov (United States)

    2015-12-01

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

  5. X-ray laser; Roentgenlaser

    Energy Technology Data Exchange (ETDEWEB)

    Samuelsen, Emil J.; Breiby, Dag W.

    2009-07-01

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

  6. X-Rays, Pregnancy and You

    Science.gov (United States)

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

  7. Self-similar hydrodynamic flow in the laser light to x-ray conversion layer of a laser-heated solid

    Energy Technology Data Exchange (ETDEWEB)

    Oparin, A.M.; Sigel, R. [Max-Planck-Institut fuer Quantenoptik, D-85748 Garching (Germany)

    1995-08-01

    Intense short-wavelength laser light may be converted into thermal soft x rays in the dense plasma formed by irradiation of a solid high-{ital Z} material. Under certain conditions, the hydrodynamic flow in the conversion layer is self-similar, and profiles of the hydrodynamic variables may be readily calculated by solving the appropriate hydrodynamic equations. It is found that the structure of the conversion layer depends on the type of equilibrium that determines the atomic physics processes of radiation emission. Varying the conditions between the limits of local thermodynamic equilibrium (LTE) and coronal equilibrium (CE) shows, that in the latter case, the radiation comes mainly from a thin layer in the dense part of the conversion layer. {copyright} {ital 1995} {ital American} {ital Institute} {ital of} {ital Physics}.

  8. XRASE: The X-Ray Spectroscopic Explorer

    DEFF Research Database (Denmark)

    Schnopper, H.W.; Silver, E.; Murray, S.

    2001-01-01

    The X-Ray Spectroscopic Explorer (XRASE) has a unique combination of features that will make it possible to address many of NASA's scientific goals. These include how galaxy clusters form, the physics and chemistry of the ISM, the heating of stellar coronae, the amount and content of intergalactic...... baryonic matter, the mass of black holes and the formation of disks and jets in AGN and galactic binaries. XRASE has a thin foil, multilayered telescope with a large collecting area up to 10 keV, especially in the Fe K alpha region (1100 cm(2)). Its microcalorimeter array combines high energy resolution (7...... eV at 6 keV) and efficiency with a field-of-view of 26 arcmin(2) . A deep orbit allows for long, continuous observations. Monitoring instruments in the optical (WOM-X), UV (TAUVEX) and hard X-RAY (GRAM) bands will offer exceptional opportunities to make simultaneous multi-wavelength observations....

  9. XRASE: The X-Ray Spectroscopic Explorer

    DEFF Research Database (Denmark)

    Schnopper, H.W.; Silver, E.; Murray, S.

    2001-01-01

    The X-Ray Spectroscopic Explorer (XRASE) has a unique combination of features that will make it possible to address many of NASA's scientific goals. These include how galaxy clusters form, the physics and chemistry of the ISM, the heating of stellar coronae, the amount and content of intergalactic...... baryonic matter, the mass of black holes and the formation of disks and jets in AGN and galactic binaries. XRASE has a thin foil, multilayered telescope with a large collecting area up to 10 keV, especially in the Fe K alpha region (1100 cm(2)). Its microcalorimeter array combines high energy resolution (7...... eV at 6 keV) and efficiency with a field-of-view of 26 arcmin(2) . A deep orbit allows for long, continuous observations. Monitoring instruments in the optical (WOM-X), UV (TAUVEX) and hard X-RAY (GRAM) bands will offer exceptional opportunities to make simultaneous multi-wavelength observations....

  10. X-ray detection using magnetic calorimeters

    Energy Technology Data Exchange (ETDEWEB)

    Schoenefeld, J. E-mail: e62@urz.uni-heidelberg.de; Enss, C.; Fleischmann, A.; Sollner, J.; Horst, K.; Adams, J.S.; Kim, Y.H.; Seidel, G.M.; Bandler, S.R

    2000-04-07

    Using a magnetic calorimeter, we have obtained an energy resolution of 13 eV in the detection of 6 keV X-rays. The calorimeter consisted of a 50 {mu}m diameter, 25 {mu}m thick Au sensor doped with 300 ppm Er. A 100x100 {mu}m square, 8 {mu}m thick Au absorber was attached to the sensor. At the operating temperature of 33 mK and with a field of 3 mT, the calorimeter had a heat capacity of 1.3x10{sup -12} J/K. With a magnetic calorimeter optimized for X-ray detection an order of magnitude improvement in resolution should be possible.

  11. Study of a scattering shield in a high heat load monochromator

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Rong, E-mail: rh66@cornell.edu [IMCA-CAT, Hauptman-Woodward Institute (United States); Meron, Mati [CARS, The University of Chicago (United States)

    2013-07-11

    The techniques for the cooling of the first crystal of a monochromator are by now mature and are used routinely to deal with the heat loads resulting from the intense beams generated by third generation synchrotron insertion device sources. However, the thermal stability of said monochromators, which crucially depends on proper shielding of X-ray scattering off the first crystal, remains a serious consideration. This will become even more so in the near future, as many synchrotron facilities are upgrading to higher beam currents and energies. During a recent upgrade of the 17-ID beamline at the APS it was recognized that accurate simulation of the spatial distribution of the power scattered off the first crystal was essential for the understanding and remediation of the observed large temperature increase of the first crystal's scattering shield. The calculation is complex, due to the broad energy spectrum of the undulator and the prevalence of multiple X-ray scattering events within the bulk of the crystal, thus the Monte Carlo method is the natural tool for such a task. A successful simulation was developed, for the purpose of the 17-ID upgrade, and used to significantly improve the design of the first crystal's scattering shield. -- Highlights: • We use the Monte Carlo method to simulate X-ray scattering from monochromator crystals. • Scattered X-ray power on each surface of the scattering shield has been calculated. • Overheating on the original shield is well explained with simulated scattering power. • The thermal stability of the modified scattering shield is satisfactory.

  12. Applications of Indirect Imaging techniques in X-ray binaries

    CERN Document Server

    Harlaftis, E T

    2000-01-01

    A review is given on aspects of indirect imaging techniques in X-ray binaries which are used as diagnostics tools for probing the X-ray dominated accretion disc physics. These techniques utilize observed properties such as the emission line profile variability, the time delays between simultaneous optical/X-ray light curves curves, the light curves of eclipsing systems and the pulsed emission from the compact object in order to reconstruct the accretion disc's line emissivity (Doppler tomography), the irradiated disc and heated secondary (echo mapping), the outer disc structure (modified eclipse mapping) and the accreting regions onto the compact object, respectively.

  13. The cryogenic cooling program in high-heat-load optics at the Advanced Photon Source

    Energy Technology Data Exchange (ETDEWEB)

    Rogers, C.S.

    1993-07-01

    This paper describes some of the aspects of the cryogenic optics program at the Advanced Photon Source (APS). A liquid-nitrogen-cooled, high-vacuum, double crystal monochromator is being fabricated at Argonne National Laboratory (ANL). A pumping system capable of delivering a variable flow rate of up to 10 gallons per minute of pressurized liquid nitrogen and removing 5 kilowatts of x-ray power is also being constructed. This specialized pumping system and monochromator will be used to test the viability of cryogenically cooled, high-heat-load synchrotron optics. It has been determined that heat transfer enhancement will be required for optics used with APS insertion devices. An analysis of a porous-matrix-enhanced monochromator crystal is presented. For the particular case investigated, a heat transfer enhancement factor of 5 to 6 was calculated.

  14. Thermal detectors as single photon X-ray spectrometers

    Science.gov (United States)

    Moseley, S. H.; Kelley, R. L.; Mather, J. C.; Mushotzky, R. F.; Szymkowiak, A. E.; Mccammon, D.

    1985-01-01

    In a thermal detector employed for X-ray spectroscopy applications, the energy of an X-ray is converted to heat in a small mass, and the energy of that X-ray inferred from the size of the temperature rise. The present investigation is concerned with the possibility to make an extremely low heat capacity calorimeter which can be employed as a thermal detector. Several types of calorimeters were fabricated and tested at temperatures as low as approximately 0.05 K. The obtained devices make use of thermistors constructed of melt-doped silicon, nuclear transmutation doped (NTD) germanium, and ion-implanted silicon with a variety of materials for the support and electrical leads. The utility of these microcalorimeters as X-ray spectrometers could be verified.

  15. X-ray Echo Spectroscopy

    Science.gov (United States)

    Shvyd'ko, Yuri

    2016-02-01

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

  16. X-ray echo spectroscopy

    CERN Document Server

    Shvyd'ko, Yuri

    2015-01-01

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

  17. X-ray Echo Spectroscopy.

    Science.gov (United States)

    Shvyd'ko, Yuri

    2016-02-26

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

  18. Are the Kinematics of the Knee Joint Altered during the Loading Response Phase of Gait in Individuals with Concurrent Knee Osteoarthritis and Complaints of Joint Instability? A Dynamic Stereo X-ray Study

    Science.gov (United States)

    Farrokhi, Shawn; Tashman, Scott; Gil, Alexandra B.; Klatt, Brian A.; Fitzgerald, G. Kelley

    2011-01-01

    Background Joint instability has been suggested as a risk factor for knee osteoarthritis and a cause of significant functional declines in those with symptomatic disease. However, the relationship between altered knee joint mechanics and self-reports of instability in individuals with knee osteoarthritis remains unclear. Methods Fourteen subjects with knee osteoarthritis and complaints of joint instability and 12 control volunteers with no history of knee disease were recruited for this study. Dynamic stereo X-ray technology was used to assess the three-dimensional kinematics of the knee joint during the loading response phase of gait. Findings Individuals with concurrent knee osteoarthritis and joint instability demonstrated significantly reduced flexion and internal/external rotation knee motion excursions during the loading response phase of gait (P knee joint at initial contact was significantly different (P knee osteoarthritis and joint instability. However, the anteroposterior and mediolateral tibiofemoral joint positions at initial contact and the corresponding total joint translations were similar between groups during the loading phase of gait. Interpretations The rotational patterns of tibiofemoral joint motion and joint alignments reported for individuals with concurrent knee osteoarthritis and joint instability are consistent with those previously established for individuals with knee osteoarthritis. Furthermore, the findings of similar translatory tibiofemoral motion between groups suggest that self-reports of episodic joint instability in individuals with knee osteoarthritis may not necessarily be associated with adaptive alterations in joint arthrokinematics. PMID:22071429

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

    Science.gov (United States)

    Heiss, Wolfgang; Brabec, Christoph

    2016-05-01

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

  20. X-ray high temperature study of interphase strains in directionally crystallized eutectics. [Heat resisting alloys:Ni-Cr-Co-Al-Ti-Mo-W, and Co-Cr-Ni

    Energy Technology Data Exchange (ETDEWEB)

    Samojlov, A.I.; Ignatova, I.A.; Khatsinskaya, I.M.; Dodonova, L.P.; Krivko, A.I.; Kozlova, V.S.

    1981-01-01

    The technique of the determination of thermal interphase strains in the matrix and reinforced phases of directionally crystallized composits (eutectics) is developed. On the basis of previously suggested general principles of calculation tested at room temperature on the eutectics ..gamma../..gamma..'- MC the peculiarities and regularities of the formation of the strained state of phases (in Ni-Cr-Co-Al-Ti-Mo-W and Co-Cr-Ni alloys ..gamma../..gamma..' - MC and CoTaC-3) in a wide temperature range from the formation temperature to the room one are presented. On the basis of experimentally determined temperature dependence of X-ray strain of the matrix phase and adopted structural model the method of the determination of the level and sign of strains during the heating and cooling of the material in the given temperature range is presented. The existence of hysteresis of the curves of the sigmasub(i)=sigmasub(i)(T) dependences, characteristic of the given composite is established. The results of X-ray tensometry are compared with the results of dilatometric studies of the same eutectics.

  1. Monitoring Chandra observations of the quasi-persistent neutron-star X-ray transient MXB 1659-29 in quiescence: the cooling curve of the heated neutron-star crust

    CERN Document Server

    Wijnands, R; Miller, J M; Lewin, W H G; Wijnands, Rudy; Homan, Jeroen; Miller, Jon M.; Lewin, Walter H. G.

    2004-01-01

    We have observed the quasi-persistent neutron-star X-ray transient and eclipsing binary MXB 1659-29 in quiescence on three occasions with Chandra. The purpose of our observations was to monitor the quiescent behavior of the source after its last prolonged (~2.5 years) outburst which ended in September 2001. The X-ray spectra of the source are consistent with thermal radiation from the neutron-star surface. We found that the bolometric flux of the source decreased by a factor of 7-9 over the time-span of 1.5 years between our first and last Chandra observations. The effective temperature also decreased, but by a factor of 1.6-1.7. The decrease in time of the bolometric flux and effective temperature can be described using exponential decay functions, with e-folding times of ~0.7 and ~3 years, respectively. Our results are consistent with the hypothesis that we observed a cooling neutron-star crust which was heated considerably during the prolonged accretion event and which is still out of thermal equilibrium w...

  2. Portable X-Ray Device

    Science.gov (United States)

    1983-01-01

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

  3. A multi-wavelength view of cooling vs. AGN heating in the X-ray luminous cool-core of Abell 3581

    CERN Document Server

    Canning, R E A; Sanders, J S; Clarke, T E; Fabian, A C; Giacintucci, S; Lal, D V; Werner, N; Allen, S W; Donahue, M; Johnstone, R M; Nulsen, P E J; Sarazin, C L

    2013-01-01

    We report the results of a multi-wavelength study of the nearby galaxy group, Abell 3581 (z=0.0218). This system hosts the most luminous cool core of any nearby group and exhibits active radio mode feedback from the super-massive black hole in its brightest group galaxy, IC 4374. The brightest galaxy has suffered multiple active galactic nuclei outbursts, blowing bubbles into the surrounding hot gas, which have resulted in the uplift of cool and cold gas into the surrounding hot intragroup medium. High velocities, indicative of an outflow, are observed close to the nucleus and coincident with the radio jet. Thin dusty filaments accompany the uplifted, ionised gas. No extended star formation is observed, however, a young cluster is detected just north of the nucleus. The direction of rise of the bubbles has changed between outbursts. This directional change is likely due to sloshing motions of the intragroup medium. These sloshing motions also appear to be actively stripping the X-ray cool core, as indicated b...

  4. Are Coronae of Magnetically Active Stars Heated by Flares? II. EUV and X-Ray Flare Statistics and the Differential Emission Measure Distribution

    CERN Document Server

    Güdel, M; Kashyap, V L; Drake, J J; Guinan, E F; Guedel, Manuel; Audard, Marc; Kashyap, Vinay L.; Drake, Jeremy J.; Guinan, Edward F.

    2003-01-01

    (Abridged) We investigate the EUV and X-ray flare rate distribution in radiated energy of the late-type active star AD Leo using long EUVE and BeppoSAX observations. We compare the observed light curves with light curves synthesized from model flares that are distributed in energy according to a power law with selectable index alpha (dN/dE ~ E^{-alpha}). Two methods are applied, the first comparing flux distributions of the binned data, and the second using the distributions of photon arrival time differences in the unbinned data. We find acceptable alpha values between 2.0-2.5 for the EUVE DS and the BeppoSAX LECS data. The BeppoSAX MECS data indicate a somewhat shallower energy distribution than the LECS data, which is attributed to the harder range of sensitivity of the MECS detector and the increasing peak temperatures of flares with increasing total (radiative) energy. The results suggest that flares can play an important role in the energy release of this active corona. We discuss caveats related to tim...

  5. On the influence of monochromator thermal deformations on X-ray focusing

    Science.gov (United States)

    Antimonov, M. A.; Khounsary, A. M.; Sandy, A. R.; Narayanan, S.; Navrotski, G.

    2016-06-01

    A cooled double crystal monochromator system is used on many high heat load X-ray synchrotron radiation beamlines in order to select, by diffraction, a narrow spectrum of the beam. Thermal deformation of the first crystal monochromator - and the potential loss of beam brightness - is often a concern. However, if downstream beam focusing is planned, the lensing effect of the monochromator must be considered even if thermal deformations are small. In this paper we report on recent experiments at an Advanced Photon Source (APS) beamline that focuses the X-ray beam using compound refractive lenses downstream of an X-ray monochromator system. Increasing the X-ray beam power by increasing the storage ring current from 100 mA to 130 mA resulted in an effective doubling of the focal distance. We show quantitatively that this is due to a lensing effect of the distorted monochromator that results in the creation of a virtual source downstream of the actual source. An analysis of the defocusing and options to mitigate this effect are explored.

  6. On the influence of monochromator thermal deformations on X-ray focusing

    Energy Technology Data Exchange (ETDEWEB)

    Antimonov, M.A. [Department of Mechanical and Industrial Engineering, University of Illinois at Chicago, Chicago, IL 60607 (United States); X-ray Science Division, Argonne National Laboratory, Argonne, IL 60439 (United States); Peter the Great St. Petersburg Polytechnic University, Saint Petersburg 195251 (Russian Federation); Khounsary, A.M., E-mail: amk@iit.edu [Department of Physics, Illinois Institute of Technology, Chicago, IL 60616 (United States); Department of Mechanical and Industrial Engineering, University of Illinois at Chicago, Chicago, IL 60607 (United States); Sandy, A.R.; Narayanan, S.; Navrotski, G. [X-ray Science Division, Argonne National Laboratory, Argonne, IL 60439 (United States)

    2016-06-01

    A cooled double crystal monochromator system is used on many high heat load X-ray synchrotron radiation beamlines in order to select, by diffraction, a narrow spectrum of the beam. Thermal deformation of the first crystal monochromator – and the potential loss of beam brightness – is often a concern. However, if downstream beam focusing is planned, the lensing effect of the monochromator must be considered even if thermal deformations are small. In this paper we report on recent experiments at an Advanced Photon Source (APS) beamline that focuses the X-ray beam using compound refractive lenses downstream of an X-ray monochromator system. Increasing the X-ray beam power by increasing the storage ring current from 100 mA to 130 mA resulted in an effective doubling of the focal distance. We show quantitatively that this is due to a lensing effect of the distorted monochromator that results in the creation of a virtual source downstream of the actual source. An analysis of the defocusing and options to mitigate this effect are explored.

  7. Recent X-Ray Laser Experiments on the COMET Facility

    Energy Technology Data Exchange (ETDEWEB)

    Dunn, J; Smith, R F; Nilsen, J; Hunter, J R; Barbee, T W; Shlyaptsev, V N; Filevich, J; Rocca, J J; Marconi, M C; Fiedorowicz, H; Bartnik, A

    2001-09-22

    The development of the transient collisional excitation x-ray laser scheme using tabletop laser systems with multiple pulse capability has progressed rapidly in the last three years. The high small-signal gain and strong x-ray output have been demonstrated for laser drive energies of typically less than 10 J. We report recent x-ray laser experiments on the Lawrence Livermore National Laboratory (LLNL) Compact Multipulse Terawatt (COMET) tabletop facility using this technique. In particular, the saturated output from the Ni-like Pd ion 4d - 4p x-ray laser at 146.8 {angstrom} has been well characterized and has potential towards a useable x-ray source in a number of applications. One important application of a short wavelength x-ray laser beam with picosecond pulse duration is the study of a high density laser-produced plasma. We report the implementation of a Mach-Zehnder type interferometer using diffraction grating optics as beam splitters designed for the Ni-like Pd laser and show results from probing a 600 ps heated plasma. In addition, gas puff targets are investigated as an x-ray laser gain medium and we report results of strong lasing on the n = 3 - 3 transitions of Ne-like Ar.

  8. Ultrafast laser pump/x-ray probe experiments

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-04-01

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

  9. Bone X-Ray (Radiography)

    Medline Plus

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

  10. Bone X-Ray (Radiography)

    Medline Plus

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

  11. X-rays and magnetism.

    Science.gov (United States)

    Fischer, Peter; Ohldag, Hendrik

    2015-09-01

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

  12. Bone X-Ray (Radiography)

    Medline Plus

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

  13. X-Ray Diffractive Optics

    Science.gov (United States)

    Dennis, Brian; Li, Mary; Skinner, Gerald

    2013-01-01

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

  14. Bone X-Ray (Radiography)

    Medline Plus

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

  15. Alpha proton x ray spectrometer

    Science.gov (United States)

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

    1994-01-01

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

  16. X-ray backscatter imaging

    Science.gov (United States)

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

    2008-04-01

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

  17. Bone X-Ray (Radiography)

    Medline Plus

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

  18. Bone X-Ray (Radiography)

    Medline Plus

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

  19. Stellar X-Ray Polarimetry

    Science.gov (United States)

    Swank, J.

    2011-01-01

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

  20. Bone X-Ray (Radiography)

    Medline Plus

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

  1. Bone X-Ray (Radiography)

    Medline Plus

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

  2. Indirect solar loading of waste heat radiators

    Energy Technology Data Exchange (ETDEWEB)

    Kirkpatrick, R.C.; Tabor, J.E.; Lindman, E.L.; Cooper, A.J.

    1988-01-01

    Waste heat from space based power systems must ultimately be radiated away into space. The local topology around the radiators must be considered from two stand-points: the scattering of sunlight onto the surfaces of the radiator and the heat load that the radiator may put on near-by components of the system. A view factor code (SNAP) developed at Los Alamos allows the computation of the steady-state radiation environment for complex 3-D geometries. An example of the code's utility is given. 4 refs., 2 figs., 1 tab.

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

    OpenAIRE

    de Groot, F. M. F.

    2001-01-01

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

  4. 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

  5. Diffraction imaging for in-situ characterization of double-crystal x-ray monochromators

    CERN Document Server

    Stoupin, Stanislav; Heald, Steve M; Brewe, Dale; Meron, Mati

    2015-01-01

    Imaging of the Bragg reflected x-ray beam is proposed and validated as an in-situ method for characterization of performance of double-crystal monochromators under the heat load of intense synchrotron radiation. A sequence of images is collected at different angular positions on the reflectivity curve of the second crystal and analyzed. The method provides rapid evaluation of the wavefront of the exit beam, which relates to local misorientation of the crystal planes along the beam footprint on the thermally distorted first crystal. The measured misorientation can be directly compared to results of finite element analysis. The imaging method offers an additional insight on the local intrinsic crystal quality over the footprint of the incident x-ray beam.

  6. X-ray reprocessing in binaries

    Science.gov (United States)

    Paul, Biswajit

    2016-07-01

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

  7. In situ x-ray diffraction study of crystal structure of Pd during hydrogen isotope loading by solid-state electrolysis at moderate temperatures 250−300 °C

    Energy Technology Data Exchange (ETDEWEB)

    Fukada, Yoshiki, E-mail: yoshiki_fukada@mail.toyota.co.jp [Toyota Motor Corporation, 1200 Mishuku, Susono-shi, Shizuoka-ken, 410-1193 (Japan); Hioki, Tatsumi; Motohiro, Tomoyoshi [Toyota Central R& D Labs.,Inc, 41-1, Yokomichi, Nagakute, Aichi, 480-1192 (Japan); Green Mobility Collaborative Research Center & Graduate School of Engineering Nagoya University, Furo-cho, Chikusa-ku, Nagoya, 464-8603 (Japan); Ohshima, Shigeki [Toyota Central R& D Labs.,Inc, 41-1, Yokomichi, Nagakute, Aichi, 480-1192 (Japan)

    2015-10-25

    Hydrogen isotopes and metal interaction with respect to Pd under high hydrogen isotope potential at moderate temperature region around 300 °C was studied. A dry electrolysis technique using BaZr{sub 1−x} Y{sub x}O{sub 3} solid state electrolyte was developed to generate high hydrogen isotope potential. Hydrogen or deuterium was loaded into a 200 nm thick Pd cathode. The cathode is deposited on SiO{sub 2} substrate and covered with the solid state electrolyte and a Pd anode layer. Time resolved in situ monochromatic x-ray diffraction measurement was performed during the electrolysis. Two phase states of the Pd cathodes with large and small lattice parameters were observed during the electrolysis. Numerous sub-micron scale voids in the Pd cathode and dendrite-like Pd precipitates in the solid state electrolyte were found from the recovered samples. Hydrogen induced super-abundant-vacancy may take role in those phenomena. The observed two phase states may be attributed to phase separation into vacancy-rich and vacancy-poor states. The voids formed in the Pd cathodes seem to be products of vacancy coalescence. Isotope effects were also observed. The deuterium loaded samples showed more rapid phase changes and more formation of voids than the hydrogen doped samples. - Highlights: • High amount hydrogen loading into Pd by all solid-state electrolysis was performed. • Two phase states with large and small lattice parameters were observed. • Lattice contractions were observed suggesting formations of super-abundant-vacancy. • The absence of mechanical pressure might stimulate the formation of the vacancy. • Sub-micron void formations were found in the Pd from recovered samples.

  8. A miniature X-ray tube based on carbon nanotube for an intraoral dental radiography

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyun Jin; Park, Han Beom; Lee, Ju Hyuk; Cho, Sung Oh [KAIST, Daejeon (Korea, Republic of)

    2016-05-15

    The number of human teeth that can be radiographically taken is limited. Moreover, at least two X-ray shots are required to get images of teeth from both sides of the mouth. In order to overcome the disadvantages of conventional dental radiography, a dental radiograph has been proposed in which an X-ray tube is inserted into the mouth while an X-ray detector is placed outside the mouth. The miniature X-ray tube is required small size to insert into the mouth. Recently, we have fabricated a miniature x-ray tube with the diameter of 7 mm using a carbon nanotube (CNT) field. But, commercialized miniature X-ray tube were adopted a thermionic type using tungsten filament. The X-ray tubes adopted thermionic emission has a disadvantage of increasing temperature of x-ray tube. So it need to cooling system to cool x-ray tube. On the other hands, X-ray tubes adopted CNT field emitters don't need cooling systems because electrons are emitted from CNT by applying high voltage without heating. We have developed the miniature x-ray tube that produce x-ray with uniform spatial distribution based on carbon nanotube field emitters. The fabricated miniature x-ray tube can be stably and reliably operated at 50kV without any vacuum pump. The developed miniature X-ray tube was applied for intraoral dental radiography that employs an intra-oral CNT-based miniature X-ray tube and extra-oral X-ray detectors. An X-ray image of many teeth was successfully obtained by a single X-ray shot using the intra-oral miniature X-ray tube system. Furthermore, images of both molar teeth of pig were simultaneously obtained by a single X-ray shot. These results show that the intraoral dental radiography, which employs an intraoral miniature X-ray tube and an extraoral X-ray detector, performs better than conventional dental radiography.

  9. Movable anode x-ray source with enhanced anode cooling

    Science.gov (United States)

    Bird, C.R.; Rockett, P.D.

    1987-08-04

    An x-ray source is disclosed having a cathode and a disc-shaped anode with a peripheral surface at constant radius from the anode axis opposed to the cathode. The anode has stub axle sections rotatably carried in heat conducting bearing plates which are mounted by thermoelectric coolers to bellows which normally bias the bearing plates to a retracted position spaced from opposing anode side faces. The bellows cooperate with the x-ray source mounting structure for forming closed passages for heat transport fluid. Flow of such fluid under pressure expands the bellows and brings the bearing plates into heat conducting contact with the anode side faces. A worm gear is mounted on a shaft and engages serrations in the anode periphery for rotating the anode when flow of coolant is terminated between x-ray emission events. 5 figs.

  10. Utilizing broadband X-rays in a Bragg coherent X-ray diffraction imaging experiment

    Energy Technology Data Exchange (ETDEWEB)

    Cha, Wonsuk; Liu, Wenjun; Harder, Ross; Xu, Ruqing; Fuoss, Paul H.; Hruszkewycz, Stephan O.

    2016-07-26

    A method is presented to simplify Bragg coherent X-ray diffraction imaging studies of complex heterogeneous crystalline materials with a two-stage screening/imaging process that utilizes polychromatic and monochromatic coherent X-rays and is compatible within situsample environments. Coherent white-beam diffraction is used to identify an individual crystal particle or grain that displays desired properties within a larger population. A three-dimensional reciprocal-space map suitable for diffraction imaging is then measured for the Bragg peak of interest using a monochromatic beam energy scan that requires no sample motion, thus simplifyingin situchamber design. This approach was demonstrated with Au nanoparticles and will enable, for example, individual grains in a polycrystalline material of specific orientation to be selected, then imaged in three dimensions while under load.

  11. Utilizing broadband X-rays in a Bragg coherent X-ray diffraction imaging experiment.

    Science.gov (United States)

    Cha, Wonsuk; Liu, Wenjun; Harder, Ross; Xu, Ruqing; Fuoss, Paul H; Hruszkewycz, Stephan O

    2016-09-01

    A method is presented to simplify Bragg coherent X-ray diffraction imaging studies of complex heterogeneous crystalline materials with a two-stage screening/imaging process that utilizes polychromatic and monochromatic coherent X-rays and is compatible with in situ sample environments. Coherent white-beam diffraction is used to identify an individual crystal particle or grain that displays desired properties within a larger population. A three-dimensional reciprocal-space map suitable for diffraction imaging is then measured for the Bragg peak of interest using a monochromatic beam energy scan that requires no sample motion, thus simplifying in situ chamber design. This approach was demonstrated with Au nanoparticles and will enable, for example, individual grains in a polycrystalline material of specific orientation to be selected, then imaged in three dimensions while under load.

  12. X-Ray-powered Macronovae

    Science.gov (United States)

    Kisaka, Shota; Ioka, Kunihito; Nakar, Ehud

    2016-02-01

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

  13. Be/X-ray binaries

    CERN Document Server

    Reig, Pablo

    2011-01-01

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

  14. X-Ray Crystallography Reagent

    Science.gov (United States)

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

    2003-01-01

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

  15. Analyzing Design Heating Loads in Superinsulated Buildings

    Energy Technology Data Exchange (ETDEWEB)

    Arena, Lois [Consortium for Advanced Residential Buildings, Norwalk, CT (United States)

    2015-06-16

    The U.S. Department of Energy’s Building America research team Consortium for Advanced Residential Buildings (CARB) worked with the EcoVillage cohousing community in Ithaca, New York, on the Third Residential EcoVillage Experience neighborhood. This communityscale project consists of 40 housing units—15 apartments and 25 single-family residences. Units range in size from 450 ft2 to 1,664 ft2 and cost from $80,000 for a studio apartment to $235,000 for a three- or four-bedroom single-family home. For the research component of this project, CARB analyzed current heating system sizing methods for superinsulated homes in cold climates to determine if changes in building load calculation methodology should be recommended. Actual heating energy use was monitored and compared to results from the Air Conditioning Contractors of America’s Manual J8 (MJ8) and the Passive House Planning Package software. Results from that research indicate that MJ8 significantly oversizes heating systems for superinsulated homes and that thermal inertia and internal gains should be considered for more accurate load calculations.

  16. X-ray ionization rates in protoplanetary discs

    CERN Document Server

    Ercolano, B

    2013-01-01

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

  17. X-RAY STUDIES REVEAL LANTHANIDE BINDING-SITES AT THE A/B5 INTERFACE OF ESCHERICHIA-COLI HEAT LABILE ENTEROTOXIN

    NARCIS (Netherlands)

    SIXMA, TK; VANSCHELTINGA, ACT; KALK, KH; WARTNA, ES; HOL, WGJ

    1992-01-01

    The crystal structure determination of heat labile enterotoxin (LT) bound to two different lanthanide ions, erbium and samarium, revealed two distinct ion binding sites in the interface of the A subunit and the B pentamer of the toxin. One of the interface sites is conserved in the very similar chol

  18. X-RAY STUDIES REVEAL LANTHANIDE BINDING-SITES AT THE A/B5 INTERFACE OF ESCHERICHIA-COLI HEAT LABILE ENTEROTOXIN

    NARCIS (Netherlands)

    SIXMA, TK; VANSCHELTINGA, ACT; KALK, KH; WARTNA, ES; HOL, WGJ

    1992-01-01

    The crystal structure determination of heat labile enterotoxin (LT) bound to two different lanthanide ions, erbium and samarium, revealed two distinct ion binding sites in the interface of the A subunit and the B pentamer of the toxin. One of the interface sites is conserved in the very similar

  19. X-Ray studies reveal lanthanide binding sites at the A/B5 interface of E. coli heat labile enterotoxin

    NARCIS (Netherlands)

    Sixma, Titia K.; Terwisscha van Scheltinga, Anke C.; Kalk, Kor H.; Zhou, Kangjing; Wartna, Ellen S.; Hol, Wim G.J.

    1992-01-01

    The crystal structure determination of heat labile enterotoxin (LT) bound to two different lanthanide ions, erbium and samarium, revealed two distinct ion binding sites in the interface of the A subunit and the B pentamer of the toxin. One of the interface sites is conserved in the very similar chol

  20. X-RAY STUDIES REVEAL LANTHANIDE BINDING-SITES AT THE A/B5 INTERFACE OF ESCHERICHIA-COLI HEAT LABILE ENTEROTOXIN

    NARCIS (Netherlands)

    SIXMA, TK; VANSCHELTINGA, ACT; KALK, KH; WARTNA, ES; HOL, WGJ

    1992-01-01

    The crystal structure determination of heat labile enterotoxin (LT) bound to two different lanthanide ions, erbium and samarium, revealed two distinct ion binding sites in the interface of the A subunit and the B pentamer of the toxin. One of the interface sites is conserved in the very similar chol

  1. Measuring the Heat Load on the Flight ASTRO-H Soft Xray Spectrometer Dewar

    Science.gov (United States)

    DiPirro, M.; Shirron, P.; Yoshida, S.; Kanao, K.; Tsunematsu, S.; Fujimoto, R.; Sneiderman, G.; Kimball, M.; Ezoe, Y.; Ishikawa, K.; Takei, Y.; Mitsuda, K.; Kelley, R.

    2015-01-01

    The Soft Xray Spectrometer (SXS) instrument on-board the ASTRO-H X-ray mission is based on microcalorimeters operating at 50 mK. Low temperature is achieved by use of an adiabatic demagnetization refrigerator (ADR) cyclically operating up to a heat sink at either 1.2 K or 4.5 K. The 1.2 K heat sink is provided by a 40 liter superfluid helium dewar. The parasitic heat to the helium from supports, plumbing, wires, and radiation, and the cyclic heat dumped by the ADR operation determine the liquid helium lifetime. To measure this lifetime we have used various techniques to rapidly achieve thermal equilibrium and then measure the boil-off rate of the helium. We have measured a parasitic heat of 650 microwatts and a cyclic heat of 100 microwatts for a total of 750 microwatts. This closely matches the predicted heat load. Starting with a fill level at launch of more than 33 liters results in a lifetime of greater than 4 years for the liquid helium. The techniques and accuracy for this measurement will be explained in this paper.

  2. 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

  3. Chest X-Ray (Chest Radiography)

    Science.gov (United States)

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

  4. A Quantitative Model of Energy Release and Heating by Time-dependent, Localized Reconnection in a Flare with a Thermal Loop-top X-ray Source

    CERN Document Server

    Longcope, D W; Carranza-Fulmer, T; Qiu, J; 10.1007/s11207-010-9635-z

    2011-01-01

    We present a quantitative model of the magnetic energy stored and then released through magnetic reconnection for a flare on 26 Feb 2004. This flare, well observed by RHESSI and TRACE, shows evidence of non-thermal electrons only for a brief, early phase. Throughout the main period of energy release there is a super-hot (T>30 MK) plasma emitting thermal bremsstrahlung atop the flare loops. Our model describes the heating and compression of such a source by localized, transient magnetic reconnection. It is a three-dimensional generalization of the Petschek model whereby Alfven-speed retraction following reconnection drives supersonic inflows parallel to the field lines, which form shocks heating, compressing, and confining a loop-top plasma plug. The confining inflows provide longer life than a freely-expanding or conductively-cooling plasma of similar size and temperature. Superposition of successive transient episodes of localized reconnection across a current sheet produces an apparently persistent, localiz...

  5. Preliminary Studies on X-Ray-sensitive Liposome

    Institute of Scientific and Technical Information of China (English)

    MENG Fan-xu; XU Hua-ping; QI Yan-fei; XU Kun; SONG Xiu-ling; NIU Shu; LI Juan

    2012-01-01

    The synthesis of a new type of X-ray-sensitive compound “di-(1-hydroxylundecyl)diselenide” and its application in the preparation of a new type of liposome with X-ray sensitivity was reported.This new liposome was synthesized to encapsulate doxorubicin hydrochloride(Dox),with its physical and chemical properties,stability,and radiation sensitivity determined.Based on the pH-gradient method,liposomal Dox was prepared via ultrasonic emulsification and then purified on a Sephadex G50 mini-column.UV spectrophotometry and liquid chromatography were used to detect the encapsulation efficiency and radiation sensitivity of the Dox-loaded liposome.The results show that through changes in release rate,this liposome shows a relative radiosensitivity.In terms of radiation sensitivity,the drug leak rate of the X-ray-sensitive Dox-loaded liposome increased gradually and peaked at 65.4% under the X-ray radiation of a dose of 10 Gy or more than 10 Gy,which is significantly different from that of ordinary liposomes.Meanwhile,X-ray-sensitive Dox-loaded liposome has a good dispersion stability,with an average particle size of approximate 120 nm.The efficiency of this liposome encapsulating Dox was 75.84%,slightly lower than that of ordinary liposomes.The X-ray-sensitive Dox-loaded liposome exhibited suspension stability within 30 d of storage at 4 ℃,without visible precipitation.Di-(1-hydroxylundecyl)diselenide is safe and noncytotoxic and compared with those of synthetic phospholipids its synthesis is low cost and does not require complex conditions.

  6. X-Ray Exam: Scoliosis (For Parents)

    Science.gov (United States)

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

  7. X-Ray Exam: Neck (For Parents)

    Science.gov (United States)

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

  8. X-Ray Exam: Femur (Upper Leg)

    Science.gov (United States)

    ... Old Feeding Your 1- to 2-Year-Old X-Ray Exam: Femur (Upper Leg) KidsHealth > For Parents > X-Ray Exam: Femur (Upper Leg) A A A ... español Radiografía: fémur What It Is A femur X-ray is a safe and painless test that ...

  9. Center for X-ray Optics, 1988

    Energy Technology Data Exchange (ETDEWEB)

    1989-04-01

    This report briefly reviews the following topics: soft-x-ray imaging; reflective optics for hard x-rays; coherent XUV sources; spectroscopy with x-rays; detectors for coronary artery imaging; synchrotron-radiation optics; and support for the advanced light source.

  10. Coherent X-ray diffraction studies of mesoscopic materials

    Energy Technology Data Exchange (ETDEWEB)

    Shabalin, Anatoly

    2015-12-15

    This thesis is devoted to three separate projects, which can be considered as independent. First, the dynamical scattering effects in the Coherent X-ray Diffractive Imaging (CXDI) method are discussed. Based on the simulation results, a straightforward method for correction for the refraction and absorption artifacts in the Bragg CXDI reconstruction is suggested. The second part summarizes the results of an Coherent X-ray Diffractive Imaging experiment with a single colloidal crystal grain. A remarkable result is that positions of individual particles in the crystal lattice have been resolved in three dimensions. The third project is devoted to X-ray diffraction experimental studies of structural evolution of colloidal crystalline films upon incremental heating. Based on the results of the analysis a model of structural evolution of a colloidal crystal upon heating on nanoscopic and mesoscopic length scales is suggested.

  11. Analyzing Design Heating Loads in Superinsulated Buildings

    Energy Technology Data Exchange (ETDEWEB)

    Arena, Lois [Consortium for Advanced Residential Buildings, Norwalk, CT (United States)

    2015-06-01

    Super-insulated homes offer many benefits including improved comfort, reduced exterior noise penetration, lower energy bills, and the ability to withstand power and fuel outages under much more comfortable conditions than a typical home. While these homes aren't necessarily constructed with excessive mass in the form of concrete floors and walls, the amount of insulation and the increase in the thickness of the building envelope can lead to a mass effect, resulting in the structures ability to store much more heat than a code built home. This results in a very low thermal inertia making the building much less sensitive to drastic temperature swings thereby decreasing the peak heating load demand. During the winter of 2013/2014, CARB monitored the energy use of three homes in climate zone 6 in an attempt to evaluate the accuracy of two different mechanical system sizing methods for low load homes. Based on the results, it is recommended that internal and solar gains be included and some credit for thermal inertia be used in sizing calculations for super insulated homes.

  12. The First Stars: formation under X-ray feedback

    CERN Document Server

    Hummel, Jacob A; Jeon, Myoungwon; Oliveri, Anthony; Bromm, Volker

    2014-01-01

    We investigate the impact of an ionising X-ray background on metal-free Population III stars within a minihalo at $z\\simeq25$ starting from cosmological initial conditions. Using the smoothed particle hydrodynamics code GADGET-2, we attain sufficient numerical resolution to follow the gas collapsing into the centre of the minihalo up to densities of $n=10^{12}\\,cm^{-3}$, at which point we form sink particles. This allows us to study how the presence of a cosmic X-ray background (CXB) affects the formation of H$_2$ and HD in the gas before it becomes fully molecular. Using a suite of simulations for a range of possible CXB models, we follow each simulation for 5000 yr after the formation of the first sink particle. The CXB provides two competing effects, with X-rays both heating the gas and enhancing its ability to cool by increasing the free electron fraction, allowing more H$_2$ to form. We find that X-ray heating dominates below $n\\sim1\\,cm^{-3}$, while the additional cooling catalysed by X-ray ionisation b...

  13. A finite element approach to x-ray optics design

    Science.gov (United States)

    Honkanen, A. P.; Ferrero, C.; Guigay, J. P.; Mocella, V.

    2017-05-01

    Dynamical diffraction in a deformed (often bent) crystal is described by the Takagi equations 1 which, in general, have to be solved numerically on a regular 2-D grid of points representing a planar cross section of the crystal in which the diffraction of an incident X-ray wavefront occurs . Presently, the majority of numerical approaches are based on a finite difference solving scheme2-4 which can be easily implemented on a regular Cartesian grid but is not suitable for deformed meshes. In this case, the inner deformed crystal structure can be taken into account, but not the shape of the crystal surface if this differs substantially from a planar profile 5,6. Conversely, a finite element method (FEM) can be easily applied to a deformed mesh and serves very well to the purpose of modelling any incident wave on an arbitrarily shaped entrance surface 7 e.g. that of a bent crystal or a crystal submitted to a strong heat load 8-10. For instance, the cylindrical shape of the surface of a strongly bent crystal plate can easily be taken into account in a FEM calculation. Bent crystals are often used as focusing optical elements in Xray beamlines 11-13. In the following, we show the implementation of a general numerical framework for describing the propagation of X-rays inside a crystal based on the solution of the Takagi equations via the COMSOL Multiphysics FEM software package (www.comsol.com). A cylindrically bent crystal will be taken as an example to illustrate the capabilities of the new approach.

  14. X-Ray Visions of SS Cygni

    Science.gov (United States)

    Young, D. L.

    2004-12-01

    The Chandra X-Ray Observatory is the most sophisticated X-ray observatory launched by NASA. Chandra is designed to observe X-rays from highenergy regions of the universe, such as X-ray binary stars. On September 14, 2000, triggered by alerts from amateur astronomers worldwide, Chandra observed the outburst of the brightest northern dwarf nova SS Cygni. The cooperation of hundreds of amateur variable star astronomers and the Chandra X-Ray scientists and spacecraft specialists provided proof that the collaboration of amateur and professional astronomers is a powerful tool to study cosmic phenomena.

  15. X-ray Spectroscopy of Cooling Cluster

    Energy Technology Data Exchange (ETDEWEB)

    Peterson, J.R.; /SLAC; Fabian, A.C.; /Cambridge U., Inst. of Astron.

    2006-01-17

    We review the X-ray spectra of the cores of clusters of galaxies. Recent high resolution X-ray spectroscopic observations have demonstrated a severe deficit of emission at the lowest X-ray temperatures as compared to that expected from simple radiative cooling models. The same observations have provided compelling evidence that the gas in the cores is cooling below half the maximum temperature. We review these results, discuss physical models of cooling clusters, and describe the X-ray instrumentation and analysis techniques used to make these observations. We discuss several viable mechanisms designed to cancel or distort the expected process of X-ray cluster cooling.

  16. Comets: mechanisms of x-ray activity

    Science.gov (United States)

    Ibadov, Subhon

    2016-07-01

    Basic mechanisms of X-ray activity of comets are considered, including D-D mechanism corresponding to generation of X-rays due to production of hot short-living plasma clumps at high-velocity collisions between cometary and interplanetary dust particles as well as M-M one corresponding to production of X-rays due to recombination of multicharge ions of solar wind plasma via charge exchange process at their collisions with molecules/atoms of the cometary atmospheres. Peculiarities of the variation of the comet X-ray spectrum and X-ray luminosity with variation of its heliocentric distance are revealed.

  17. X-rays from solar system objects

    CERN Document Server

    Bhardwaj, Anil; Gladstone, G Randall; Cravens, Thomas E; Lisse, Carey M; Dennerl, Konrad; Branduardi-Raymont, Graziella; Wargelin, Bradford J; Waite, J Hunter; Robertson, Ina; Ostgaard, Nikolai; Beiersdorfer, Peter; Snowden, Steven L; Kharchenko, Vasili; 10.1016/j.pss.2006.11.009

    2010-01-01

    During the last few years our knowledge about the X-ray emission from bodies within the solar system has significantly improved. Several new solar system objects are now known to shine in X-rays at energies below 2 keV. Apart from the Sun, the known X-ray emitters now include planets (Venus, Earth, Mars, Jupiter, and Saturn), planetary satellites (Moon, Io, Europa, and Ganymede), all active comets, the Io plasma torus (IPT), the rings of Saturn, the coronae (exospheres) of Earth and Mars, and the heliosphere. The advent of higher-resolution X-ray spectroscopy with the Chandra and XMM-Newton X-ray observatories has been of great benefit in advancing the field of planetary X-ray astronomy. Progress in modeling X-ray emission, laboratory studies of X-ray production, and theoretical calculations of cross-sections, have all contributed to our understanding of processes that produce X-rays from the solar system bodies. At Jupiter and Earth, both auroral and non-auroral disk X-ray emissions have been observed. X-ray...

  18. Phase-contrast X-ray CT

    Energy Technology Data Exchange (ETDEWEB)

    Momose, Atsushi [Hitachi Ltd., Hatoyama, Saitama (Japan). Advanced Research Lab.

    1996-08-01

    X-ray transmission imaging that creates image contrast from the distribution of the X-ray absorption coefficient is not sensitive to materials consisting of light elements such as hydrogen, carbon, nitrogen, and oxygen. On the other hand, the X-ray phase shift caused by the light elements is substantial enough to be detected even when absorption is almost zero. Hence, phase-contrast X-ray imaging is a promising technique for observing the structure inside biological soft tissues without the need for staining and without serious radiation exposure. Using fringe scanning X-ray interferometry, the X-ray phase shift caused by an object was measured. Three-dimensional image reconstruction of cancerous tissues using the measured phase shifts was enabled under tomographic configuration phase-contrast X-ray computed tomography (CT). (author)

  19. New Limits on 21cm EoR From PAPER-32 Consistent with an X-Ray Heated IGM at z=7.7

    CERN Document Server

    Parsons, Aaron R; Aguirre, James E; Ali, Zaki S; Bradley, Richard F; Carilli, Chris L; DeBoer, David R; Dexter, Matthew R; Gugliucci, Nicole E; Jacobs, Daniel C; Klima, Pat; MacMahon, David H E; Manley, Jason R; Moore, David F; Pober, Jonathan C; Stefan, Irina I; Walbrugh, William P

    2013-01-01

    We present new constraints on the 21cm Epoch of Reionization (EoR) power spectrum derived from 3 months of observing with a 32-antenna, dual-polarization deployment of the Donald C. Backer Precision Array for Probing the Epoch of Reionization (PAPER) in South Africa. In this paper, we demonstrate the efficacy of the delay-spectrum approach to avoiding foregrounds, achieving over 8 orders of magnitude of foreground suppression (in mK^2). Combining this approach with a procedure for removing off-diagonal covariances arising from instrumental systematics, we achieve a best 2-sigma upper limit of 52 mK^2 for k=0.11 h Mpc^-1 at z=7.7. This limit falls within an order of magnitude of the brighter predictions of the expected 21cm EoR signal level. Using the upper limits set by these measurements, we generate new constraints on the brightness temperature of 21cm emission in neutral regions for various reionization models. We show that for several ionization models, heating of the neutral intergalactic medium (IGM) is...

  20. Full-field transmission x-ray imaging with confocal polycapillary x-ray optics.

    Science.gov (United States)

    Sun, Tianxi; Macdonald, C A

    2013-02-07

    A transmission x-ray imaging setup based on a confocal combination of a polycapillary focusing x-ray optic followed by a polycapillary collimating x-ray optic was designed and demonstrated to have good resolution, better than the unmagnified pixel size and unlimited by the x-ray tube spot size. This imaging setup has potential application in x-ray imaging for small samples, for example, for histology specimens.

  1. AN ANALYTIC MODEL FOR TRANSIENT COLLISIONAL X-RAY LASERS

    Institute of Scientific and Technical Information of China (English)

    LI YING-JUN; ZHANG JIE; TENG Al-PING

    2001-01-01

    A set of similarity equations is derived to describe the hydrodynamics of transient X-ray lasers from slab plasmas generated by combined irradiation of nanosecond and picosecond laser pulses. By separating nanosecond and picosecond laser heating processes into different periods, analytical solutions are obtained for the similarity equations. The calculated results are in agreement with numerical simulations and experimental data.

  2. X-ray tubes study and design

    CERN Document Server

    Sardari, D

    1990-01-01

    This thesis contain both theoretical and experimental works. Theoretical aspect includes X-Ray tubes case study and design principles, in the introduced design process, anode-cathode distance, vacuum needed, filament size, anode face angle and shape and size of focusing electrodes can be found. A method for specification of tungsten lager thickness on anode is also introduced. Using computer simulation, electron trajectory between cathode-anode is obtained, This work is presented in the first International Conference on Control and Modeling, Tehran, 1990. Experimental work contains manufacturing more than 10 tubes and test each of them. One of these tubes can with stand up to 50 KV. Filament can be heated by passing a 2.1 A current. In these conditions anode current is 1.2 m A. Using this tube, some radiographs have been taken.

  3. X-ray pushing of a mechanical microswing.

    Science.gov (United States)

    Siria, A; Rodrigues, M S; Dhez, O; Schwartz, W; Torricelli, G; Ledenmat, S; Rochat, N; Auvert, G; Bikondoa, O; Metzger, T H; Wermeille, D; Felici, R; Comin, F; Chevrier, J

    2008-11-05

    We report here for the first time the combination of x-ray synchrotron light and a micro-electro-mechanical system (MEMS). We show how it is possible to modulate in real time a MEMS mass distribution to induce a nanometric and tunable mechanical oscillation. The quantitative experimental demonstration we present here uses periodic thermal dilatation of a Ge microcrystal attached to a Si microlever, induced by controlled absorption of an intensity modulated x-ray microbeam. The mechanism proposed can be envisaged either for the detection of small heat flux or for the actuation of a mechanical system.

  4. Controlling X-rays With Light

    Energy Technology Data Exchange (ETDEWEB)

    Glover, Ernie; Hertlein, Marcus; Southworth, Steve; Allison, Tom; van Tilborg, Jeroen; Kanter, Elliot; Krassig, B.; Varma, H.; Rude, Bruce; Santra, Robin; Belkacem, Ali; Young, Linda

    2010-08-02

    Ultrafast x-ray science is an exciting frontier that promises the visualization of electronic, atomic and molecular dynamics on atomic time and length scales. A largelyunexplored area of ultrafast x-ray science is the use of light to control how x-rays interact with matter. In order to extend control concepts established for long wavelengthprobes to the x-ray regime, the optical control field must drive a coherent electronic response on a timescale comparable to femtosecond core-hole lifetimes. An intense field is required to achieve this rapid response. Here an intense optical control pulse isobserved to efficiently modulate photoelectric absorption for x-rays and to create an ultrafast transparency window. We demonstrate an application of x-ray transparencyrelevant to ultrafast x-ray sources: an all-photonic temporal cross-correlation measurement of a femtosecond x-ray pulse. The ability to control x-ray/matterinteractions with light will create new opportunities at current and next-generation x-ray light sources.

  5. The Herbig Ae Star HD 163296 in X-Rays

    Science.gov (United States)

    Swartz, Douglas A.; Drake, Jeremy J.; Elsner, Ronald F.; Ghosh, Kajal K.; Grady, Carol A.; Wassell, Edward

    2004-01-01

    Chandra X-ray imaging spectroscopy of the nearby Herbig Ae star HD 163296 at 100 AU angular resolution is reported. A point-like, soft (kT approximately 0.5 approximately kev), emission-line source is detected at the location of the star with an X-ray luminosity of 4.0e29 erg/s. In addition, faint emission along the direction of a previously-detected Ly-alpha-emitting jet and Herbig-Haro outflow may be present. The relatively low luminosity, lack of a hard spectral component, and absence of strong X-ray variability in HD 163296 can be explained as originating from optically-thin shock-heated gas accreting onto the stellar surface along magnetic field lines. This would require a (dipole) magnetic field strength at the surface of HD 163296 of at least approximately 100 approximately G and perhaps as high as several kG.

  6. Is Coronal X-ray Emission Energized By Electric Currents?

    Science.gov (United States)

    Ishibashi, Kazunori; Metcalf, T.; Lites, B.

    2007-05-01

    We examine the spatial correlation between coronal X-ray emission observed with the Hinode X-Ray Telescope and electric currents observed with the Hinode Solar Optical Telescope Spectro-polarimeter. We determine to what extent the X-ray brightness is correlated with electric current density and hence to what extent the hot corona is energized by electric currents which flow through the photosphere. We will also consider whether the currents reach the corona to heat the coronal plasma or whether they predominantly close below the corona. Hinode is an international project supported by JAXA, NASA, PPARC and ESA. We are grateful to the Hinode team for all their efforts in the design, development and operation of the mission.

  7. The long X-ray tail in Zwicky 8338

    CERN Document Server

    Schellenberger, G

    2015-01-01

    The interaction processes in galaxy clusters between the hot ionized gas (ICM) and the member galaxies are of crucial importance in order to understand the dynamics in galaxy clusters, the chemical enrichment processes and the validity of their hydrostatic mass estimates. Recently, several X-ray tails associated to gas which was partly stripped of galaxies have been discovered. Here we report on the X-ray tail in the 3 keV galaxy cluster Zwicky 8338, which might be the longest ever observed. We derive the properties of the galaxy cluster environment and give hints on the substructure present in this X-ray tail, which is very likely associated to the galaxy CGCG254-021. The X-ray tail is extraordinarily luminous ($2\\times10^{42}$ erg/s), the thermal emission has a temperature of 0.8 keV and the X-ray luminous gas might be stripped off completely from the galaxy. From the assumptions on the 3D geometry we estimate the gas mass fraction (< 0.1%) and conclude that the gas has been compressed and/or heated.

  8. Expectation for the X-ray Galactic Halo

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    We present an estimate of the strength and spectrum of the X-ray background from the warm gas associated with the Galactic halo. This investigation is motivated primarily by the recent detection of a spatially variable soft X-ray component towards the north Galactic polar cap by Kuntz et al. (2001), suggesting that the warm gas heated by gravitational shocks of the Galactic halo may produce a significant contribution to the soft X-ray sky. Another purpose of the study is to refine the recent theoretical prediction of the X-ray spectrum from the Galactic alo by Xue (2001) who adopted an ideal and simple isothermal model for the gas and dark matter distributions of the Galactic halo. We use the universal density profile for the dark matter distributions of the Galactic halo to evaluate the Xray properties of the warm gas either in hydrostatic equilibrium with, or tracing the underlying gravitational potential of the Galaxy. It has been shown that our prediction is consistent with the measured soft X-ray component towards the north Galactic polar cap if the gas fraction is taken to be ~ 0.005.

  9. Correlated X-ray/Ultraviolet/Optical Variability in NGC 6814

    CERN Document Server

    Troyer, Jon; Cackett, Edward; Bentz, Misty; Goad, Michael; Horne, Keith; Seals, James

    2015-01-01

    We present results of a 3-month combined X-ray/UV/optical monitoring campaign of the Seyfert 1 galaxy NGC 6814. The object was monitored by Swift from June through August 2012 in the X-ray and UV bands and by the Liverpool Telescope from May through July 2012 in B and V. The light curves are variable and significantly correlated between wavebands. Using cross-correlation analysis, we compute the time lag between the X-ray and lower energy bands. These lags are thought to be associated with the light travel time between the central X-ray emitting region and areas further out on the accretion disc. The computed lags support a thermal reprocessing scenario in which X-ray photons heat the disc and are reprocessed into lower energy photons. Additionally, we fit the lightcurves using CREAM, a Markov Chain Monte Carlo code for a standard disc. The best-fitting standard disc model yields unreasonably high super-Eddington accretion rates. Assuming more reasonable accretion rates would result in significantly under-pre...

  10. Diffractive X-Ray Telescopes

    Science.gov (United States)

    Skinner, Gerald K.

    2010-01-01

    Diffractive X-ray telescopes, using zone plates, phase Fresnel lenses, or related optical elements have the potential to provide astronomers with true imaging capability with resolution many orders of magnitude better than available in any other waveband. Lenses that would be relatively easy to fabricate could have an angular resolution of the order of micro-arc-seconds or even better, that would allow, for example, imaging of the distorted spacetime in the immediate vicinity of the super-massive black holes in the center of active galaxies. What then is precluding their immediate adoption? Extremely long focal lengths, very limited bandwidth, and difficulty stabilizing the image are the main problems. The history, and status of the development of such lenses is reviewed here and the prospects for managing the challenges that they present are discussed.

  11. Diffractive X-ray Telescopes

    CERN Document Server

    Skinner, Gerald K

    2010-01-01

    Diffractive X-ray telescopes using zone plates, phase Fresnel lenses, or related optical elements have the potential to provide astronomers with true imaging capability with resolution several orders of magnitude better than available in any other waveband. Lenses that would be relatively easy to fabricate could have an angular resolution of the order of micro-arc-seconds or even better, that would allow, for example, imaging of the distorted space- time in the immediate vicinity of the super-massive black holes in the center of active galaxies What then is precluding their immediate adoption? Extremely long focal lengths, very limited bandwidth, and difficulty stabilizing the image are the main problems. The history, and status of the development of such lenses is reviewed here and the prospects for managing the challenges that they present are discussed.

  12. Direct Observations of the (Alpha to Gamma) Transformation at Different Input Powers in the Heat Affected Zone of 1045 C-Mn Steel Arc Welds Observed by Spatially Resolved X-Ray Diffraction

    Energy Technology Data Exchange (ETDEWEB)

    Palmer, T A; Elmer, J W

    2005-03-16

    Spatially Resolved X-Ray Diffraction (SRXRD) experiments have been performed during Gas Tungsten Arc (GTA) welding of AISI 1045 C-Mn steel at input powers ranging from 1000 W to 3750 W. In situ diffraction patterns taken at discreet locations across the width of the heat affected zone (HAZ) near the peak of the heating cycle in each weld show regions containing austenite ({gamma}), ferrite and austenite ({alpha}+{gamma}), and ferrite ({alpha}). Changes in input power have a demonstrated effect on the resulting sizes of these regions. The largest effect is on the {gamma} phase region, which nearly triples in width with increasing input power, while the width of the surrounding two phase {alpha}+{gamma} region remains relatively constant. An analysis of the diffraction patterns obtained across this range of locations allows the formation of austenite from the base metal microstructure to be monitored. After the completion of the {alpha} {yields} {gamma} transformation, a splitting of the austenite peaks is observed at temperatures between approximately 860 C and 1290 C. This splitting in the austenite peaks results from the dissolution of cementite laths originally present in the base metal pearlite, which remain after the completion of the {alpha} {yields} {gamma} transformation, and represents the formation of a second more highly alloyed austenite constituent. With increasing temperatures, carbon, originally present in the cementite laths, diffuses from the second newly formed austenite constituent to the original austenite constituent. Eventually, a homogeneous austenitic microstructure is produced at temperatures of approximately 1300 C and above, depending on the weld input power.

  13. Handbook of X-Ray Data

    CERN Document Server

    Zschornack, Günter

    2007-01-01

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

  14. Soft X ray properties of the Geminga pulsar

    Science.gov (United States)

    Halpern, J. P.; Ruderman, M.

    1993-01-01

    The ROSAT soft x ray spectrum and pulse profile of the Geminga pulsar are analyzed and interpreted in terms of thermal emission from the surface of the neutron star. The x ray spectrum appears to consist of two blackbody components with T1 = (5.2 +/- 1.0) x 10 5 K and T2 approximately 3 x 106 K, respectively. The inferred ratio of surface areas, A2/A1, is approximately 3 x 10-5. Both components are highly modulated at the pulsar rotation period, but the harder x ray pulse is narrower, and leads the main (soft) x ray pulse by about 105 deg of phase. The soft x ray component is interpreted as photospheric cooling of much of the neutron star's surface area, while the small, hot region could be part of the much smaller polar cap heated by energetic particles flowing inward from the magnetospheric accelerator which is responsible for the production of Geminga's gamma rays. Geminga's gamma ray emission is consistent with outer-magnetosphere accelerator models for highly inclined dipoles. These predict the beaming of energetic gamma rays close enough to the star to give copious e(+/-) production in the stellar magnetic field and a large circumstellar pair density from pair inflow toward the surface. These pairs may quench radio emission, and also reflect most of the hard polar cap x rays back to the stellar surface by cyclotron resonance scattering. They are then reemitted from that much larger area at the lower temperature T1. The single-peaked nature of the x ray pulse and its energy-dependent phase suggest an off-center dipole geometry for the surface magnetic field. Under the assumption that the soft x ray emission comes from the full surface of a neutron star of radius R = 10 km, a distance estimate of (150-400) pc is derived. This range is consistent with the fit interstellar column density of (1.5 +/- 0.5) x 1020 cm-2. Distances less than 150 pc are probably ruled out both by the lower limit on the column density, and also by the requirement that the Rayleigh

  15. Starburst-driven galactic winds - I. Energetics and intrinsic X-ray emission

    Science.gov (United States)

    Strickland, David K.; Stevens, Ian R.

    2000-05-01

    Starburst-driven galactic winds are responsible for the transport of mass, in particular metal-enriched gas, and energy out of galaxies and into the intergalactic medium. These outflows directly affect the chemical evolution of galaxies, and heat and enrich the intergalactic and intercluster medium. Currently, several basic problems preclude quantitative measurements of the impact of galactic winds: the unknown filling factors of, in particular, the soft X-ray-emitting gas prevent accurate measurements of densities, masses and energy content; multiphase temperature distributions of unknown complexity bias X-ray-determined abundances; unknown amounts of energy and mass may reside in hard to observe T~105K and T~107.5K phases; and the relative balance of thermal versus kinetic energy in galactic winds is not known. In an effort to address these problems, we perform an extensive hydrodynamical parameter study of starburst-driven galactic winds, motivated by the latest observation data on the best-studied starburst galaxy M82. We study how the wind dynamics, morphology and X-ray emission depend on the ISM distribution of the host galaxy, the starburst star formation history and strength, and the presence and distribution of mass-loading by dense clouds. We also investigate and discuss the influence of finite numerical resolution on the results of these simulations. We find that the soft X-ray emission from galactic winds comes from low filling factor (ηfactor that must be taken into account when attempting to constrain wind energetics observationally. We also find that galactic winds are efficient at transporting large amounts of energy out of the host galaxy, in contrast to their inefficiency at transporting mass out of star-forming galaxies.

  16. X-ray data booklet. Revision

    Energy Technology Data Exchange (ETDEWEB)

    Vaughan, D. (ed.)

    1986-04-01

    A compilation of data is presented. Included are properties of the elements, electron binding energies, characteristic x-ray energies, fluorescence yields for K and L shells, Auger energies, energy levels for hydrogen-, helium-, and neonlike ions, scattering factors and mass absorption coefficients, and transmission bands of selected filters. Also included are selected reprints on scattering processes, x-ray sources, optics, x-ray detectors, and synchrotron radiation facilities. (WRF)

  17. X-ray generation using carbon nanotubes

    OpenAIRE

    Parmee, Richard J.; Collins, Clare M.; William I. Milne; Cole, Matthew T.

    2015-01-01

    This is the final published version. It first appeared at http://www.nanoconvergencejournal.com/content/2/1/1. Since the discovery of X-rays over a century ago the techniques applied to the engineering of X-ray sources have remained relatively unchanged. From the inception of thermionic electron sources, which, due to simplicity of fabrication, remain central to almost all X-ray applications, there have been few fundamental technological advances. However, with the emergence of ever more d...

  18. Applications of soft x-ray lasers

    Energy Technology Data Exchange (ETDEWEB)

    Skinner, C.H.

    1993-08-01

    The high brightness and short pulse duration of soft x-ray lasers provide unique advantages for novel applications. Imaging of biological specimens using x-ray lasers has been demonstrated by several groups. Other applications to fields such as chemistry, material science, plasma diagnostics, and lithography are beginning to emerge. We review the current status of soft x-ray lasers from the perspective of applications, and present an overview of the applications currently being developed.

  19. Topological X-Rays and MRIs

    Science.gov (United States)

    Lynch, Mark

    2002-01-01

    Let K be a compact subset of the interior of the unit disk D in the plane and suppose one can't see through the boundary of D and identify K. However, assume that one can take "topological X-rays" of D which measure the "density" of K along the lines of the X-rays. By taking these X-rays from all directions, a "topological MRI" is generated for…

  20. Observation of femtosecond X-ray interactions with matter using an X-ray-X-ray pump-probe scheme.

    Science.gov (United States)

    Inoue, Ichiro; Inubushi, Yuichi; Sato, Takahiro; Tono, Kensuke; Katayama, Tetsuo; Kameshima, Takashi; Ogawa, Kanade; Togashi, Tadashi; Owada, Shigeki; Amemiya, Yoshiyuki; Tanaka, Takashi; Hara, Toru; Yabashi, Makina

    2016-02-01

    Resolution in the X-ray structure determination of noncrystalline samples has been limited to several tens of nanometers, because deep X-ray irradiation required for enhanced resolution causes radiation damage to samples. However, theoretical studies predict that the femtosecond (fs) durations of X-ray free-electron laser (XFEL) pulses make it possible to record scattering signals before the initiation of X-ray damage processes; thus, an ultraintense X-ray beam can be used beyond the conventional limit of radiation dose. Here, we verify this scenario by directly observing femtosecond X-ray damage processes in diamond irradiated with extraordinarily intense (∼10(19) W/cm(2)) XFEL pulses. An X-ray pump-probe diffraction scheme was developed in this study; tightly focused double-5-fs XFEL pulses with time separations ranging from sub-fs to 80 fs were used to excite (i.e., pump) the diamond and characterize (i.e., probe) the temporal changes of the crystalline structures through Bragg reflection. It was found that the pump and probe diffraction intensities remain almost constant for shorter time separations of the double pulse, whereas the probe diffraction intensities decreased after 20 fs following pump pulse irradiation due to the X-ray-induced atomic displacement. This result indicates that sub-10-fs XFEL pulses enable conductions of damageless structural determinations and supports the validity of the theoretical predictions of ultraintense X-ray-matter interactions. The X-ray pump-probe scheme demonstrated here would be effective for understanding ultraintense X-ray-matter interactions, which will greatly stimulate advanced XFEL applications, such as atomic structure determination of a single molecule and generation of exotic matters with high energy densities.

  1. Static Heat Loads in the LHC Arc Cryostats: Final Assessment

    CERN Document Server

    Parma, V

    2010-01-01

    This note presents the final assessment of the static heat loads in the LHC arc cryostats, using different experimental methods during the first commissioning period in 2007. This assessment further develops and completes previous estimates made during the commissioning of sector 7_8 [1]. The estimate of the helium inventory, a prerequisite for the heat load calculation, is also presented. Heat loads to the cold mass are evaluated from the internal energy balance during natural as well as powered warm-ups of the helium baths in different subsector. The helium inventory is calculated from the internal energy balance during powered warm-ups and matched with previous assessments. Furthermore, heat loads to the thermal shield are estimated from the non-isothermal cooling of the supercritical helium in line E. The comparison of measured heat loads with previous estimates and with budgeted values is then presented, while their correlation with some important parameters like insulation vacuum pressure and some heat ...

  2. Phase-contrast X-ray CT

    Energy Technology Data Exchange (ETDEWEB)

    Momose, Atsushi [Hitachi Ltd., Saitama (Japan). Advanced Research Laboratory; Takeda, Tohoru; Itai, Yuji

    1995-12-01

    Phase-contrast X-ray computed tomography (CT) enabling the observation of biological soft tissues without contrast enhancement has been developed. The X-ray phase shift caused by an object is measured and input to a standard CT reconstruction algorithm. A thousand times increase in the image sensitivity to soft tissues is achieved compared with the conventional CT using absorption contrast. This is because the X-ray phase shift cross section of light elements is about a thousand times larger than the absorption cross section. The phase shift is detected using an X-ray interferometer and computer analyses of interference patterns. Experiments were performed using a synchrotron X-ray source. Excellent image sensitivity is demonstrated in the observation of cancerous rabbit liver. The CT images distinguish cancer lesion from normal liver tissue and, moreover, visualize the pathological condition in the lesion. Although the X-ray energy employed and the present observation area size are not suitable for medical applications as they are, phase-contrast X-ray CT is promising for investigating the internal structure of soft tissue which is almost transparent for X-rays. The high sensitivity also provides the advantage of reducing X-ray doses. (author).

  3. An Imaging X-Ray Polarimetry Mission

    Science.gov (United States)

    Weisskopf, Martin C.; Bellazini, Ronaldo; Costa, Enrico; Ramsey, Brian; O'Dell, Steve; Elsner, Ronald; Pavlov, George; Matt, Giorgio; Kaspi, Victoria; Tennant, Allyn; Coppi, Paolo; Wu, Kinwah; Siegmund, Oswald

    2008-01-01

    Technical progress both in x-ray optics and in polarization-sensitive x-ray detectors, which our groups have pioneered, enables a scientifically powerful---yet inexpensive---dedicated mission for imaging x-ray polarimetry. Such a mission is sufficiently sensitive to measure x-ray (linear) polarization for a broad range of cosmic sources --particularly those involving neutron stars, stellar black holes, and supermassive black holes (active galactic nuclei). We describe the technical elements, discuss a mission concept, and synopsize the important physical and astrophysical questions such a mission would address.

  4. The efficacy of x-ray pelvimetry

    Energy Technology Data Exchange (ETDEWEB)

    Barton, J.J. (Univ. of Illinois, Chicago); Garbaciak, J.A. Jr.; Ryan, G.M., Jr.

    1982-06-01

    Comparison is made of x-ray pelvimetry use on a public and private service in 1974 with experience in 1979, when the clinic service did no x-ray pelvimetry while the private service continued as before. It is concluded that the use of x-ray pelvimetry is inadequate as a predictor of cesarean section because of cephalopelvic disproportion, does not improve neonatal mortality, and poses potential hazards to the mother and fetus. Its use in the management of breech presentations is not currently established by our data. Guidelines are presented for the management of patients in labor without using x-ray pelvimetry.

  5. Symbiotic Stars in X-rays

    Science.gov (United States)

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

    2014-01-01

    Until recently, symbiotic binary systems in which a white dwarf accretes from a red giant were thought to be mainly a soft X-ray population. Here we describe the detection with the X-ray Telescope (XRT) on the Swift satellite of 9 white dwarf symbiotics that were not previously known to be X-ray sources and one that was previously detected as a supersoft X-ray source. The 9 new X-ray detections were the result of a survey of 41 symbiotic stars, and they increase the number of symbiotic stars known to be X-ray sources by approximately 30%. Swift/XRT detected all of the new X-ray sources at energies greater than 2 keV. Their X-ray spectra are consistent with thermal emission and fall naturally into three distinct groups. The first group contains those sources with a single, highly absorbed hard component, which we identify as probably coming from an accretion-disk boundary layer. The second group is composed of those sources with a single, soft X-ray spectral component, which likely arises in a region where low-velocity shocks produce X-ray emission, i.e. a colliding-wind region. The third group consists of those sources with both hard and soft X-ray spectral components. We also find that unlike in the optical, where rapid, stochastic brightness variations from the accretion disk typically are not seen, detectable UV flickering is a common property of symbiotic stars. Supporting our physical interpretation of the two X-ray spectral components, simultaneous Swift UV photometry shows that symbiotic stars with harder X-ray emission tend to have stronger UV flickering, which is usually associated with accretion through a disk. To place these new observations in the context of previous work on X-ray emission from symbiotic stars, we modified and extended the alpha/beta/gamma classification scheme for symbiotic-star X-ray spectra that was introduced by Muerset et al. based upon observations with the ROSAT satellite, to include a new sigma classification for sources with

  6. Ultrashort X-ray pulse science

    Energy Technology Data Exchange (ETDEWEB)

    Chin, Alan Hap [Univ. of California, Berkeley, CA (US). Dept. of Physics; Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    1998-05-01

    A variety of phenomena involves atomic motion on the femtosecond time-scale. These phenomena have been studied using ultrashort optical pulses, which indirectly probe atomic positions through changes in optical properties. Because x-rays can more directly probe atomic positions, ultrashort x-ray pulses are better suited for the study of ultrafast structural dynamics. One approach towards generating ultrashort x-ray pulses is by 90° Thomson scattering between terawatt laser pulses and relativistic electrons. Using this technique, the author generated ~ 300 fs, 30 keV (0.4 Å) x-ray pulses. These x-ray pulses are absolutely synchronized with ultrashort laser pulses, allowing femtosecond optical pump/x-ray probe experiments to be performed. Using the right-angle Thomson scattering x-ray source, the author performed time-resolved x-ray diffraction studies of laser-perturbated InSb. These experiments revealed a delayed onset of lattice expansion. This delay is due to the energy relaxation from a dense electron-hole plasma to the lattice. The dense electron-hole plasma first undergoes Auger recombination, which reduces the carrier concentration while maintaining energy content. Longitudinal-optic (LO) phonon emission then couples energy to the lattice. LO phonon decay into acoustic phonons, and acoustic phonon propagation then causes the growth of a thermally expanded layer. Source characterization is instrumental in utilizing ultrashort x-ray pulses in time-resolved x-ray spectroscopies. By measurement of the electron beam diameter at the generation point, the pulse duration of the Thomson scattered x-rays is determined. Analysis of the Thomson scattered x-ray beam properties also provides a novel means of electron bunch characterization. Although the pulse duration is inferred for the Thomson scattering x-ray source, direct measurement is required for other x-ray pulse sources. A method based on the laser-assisted photoelectric effect (LAPE) has been demonstrated as a

  7. Hard X-ray Modulation Telescope

    Institute of Scientific and Technical Information of China (English)

    LU Fangjun

    2011-01-01

    The Hard X-ray Modulation Telescope (HXMT) will be China's first astronomical satellite. On board HXMT there are three kinds of slat-collimated telescopes, the High Energy X-ray Telescope (HE, 20-250 keV, 5000 cm^2), the Medium Energy X-ray Telescope (ME, 5-30 keV, 952 cm^2), and the Low Energy X-ray Telescope (LE, 1-15 keV, 384 cm^2).

  8. Ultrashort X-ray pulse science

    Energy Technology Data Exchange (ETDEWEB)

    Chin, Alan Hap [Univ. of California, Berkeley, CA (US). Dept. of Physics; Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    1998-05-01

    A variety of phenomena involves atomic motion on the femtosecond time-scale. These phenomena have been studied using ultrashort optical pulses, which indirectly probe atomic positions through changes in optical properties. Because x-rays can more directly probe atomic positions, ultrashort x-ray pulses are better suited for the study of ultrafast structural dynamics. One approach towards generating ultrashort x-ray pulses is by 90{sup o} Thomson scattering between terawatt laser pulses and relativistic electrons. Using this technique, the author generated {approx} 300 fs, 30 keV (0.4 {angstrom}) x-ray pulses. These x-ray pulses are absolutely synchronized with ultrashort laser pulses, allowing femtosecond optical pump/x-ray probe experiments to be performed. Using the right-angle Thomson scattering x-ray source, the author performed time-resolved x-ray diffraction studies of laser-perturbated InSb. These experiments revealed a delayed onset of lattice expansion. This delay is due to the energy relaxation from a dense electron-hole plasma to the lattice. The dense electron-hole plasma first undergoes Auger recombination, which reduces the carrier concentration while maintaining energy content. Longitudinal-optic (LO) phonon emission then couples energy to the lattice. LO phonon decay into acoustic phonons, and acoustic phonon propagation then causes the growth of a thermally expanded layer. Source characterization is instrumental in utilizing ultrashort x-ray pulses in time-resolved x-ray spectroscopies. By measurement of the electron beam diameter at the generation point, the pulse duration of the Thomson scattered x-rays is determined. Analysis of the Thomson scattered x-ray beam properties also provides a novel means of electron bunch characterization. Although the pulse duration is inferred for the Thomson scattering x-ray source, direct measurement is required for other x-ray pulse sources. A method based on the laser-assisted photoelectric effect (LAPE) has

  9. An Imaging X-Ray Polarimetry Mission

    Science.gov (United States)

    Weisskopf, Martin C.; Bellazini, Ronaldo; Costa, Enrico; Ramsey, Brian; O'Dell, Steve; Elsner, Ronald; Pavlov, George; Matt, Giorgio; Kaspi, Victoria; Tennant, Allyn; hide

    2008-01-01

    Technical progress both in x-ray optics and in polarization-sensitive x-ray detectors, which our groups have pioneered, enables a scientifically powerful---yet inexpensive---dedicated mission for imaging x-ray polarimetry. Such a mission is sufficiently sensitive to measure x-ray (linear) polarization for a broad range of cosmic sources --particularly those involving neutron stars, stellar black holes, and supermassive black holes (active galactic nuclei). We describe the technical elements, discuss a mission concept, and synopsize the important physical and astrophysical questions such a mission would address.

  10. X-ray emission from comets.

    Science.gov (United States)

    Cravens, T E

    2002-05-10

    The discovery of x-ray emission from comet Hyakutake was surprising given that comets are known to be cold. Observations by x-ray satellites such as the Röntgen Satellite (ROSAT) indicate that x-rays are produced by almost all comets. Theoretical and observational work has demonstrated that charge-exchange collisions of highly charged solar wind ions with cometary neutral species can explain this emission. X-ray observations of comets and other solar system objects may be used to determine the structure and dynamics of the solar wind.

  11. X-ray pulsar rush in 1998

    Energy Technology Data Exchange (ETDEWEB)

    Imanishi, K.; Tsujimoto, K.; Nishiuchi, Mamiko; Yokogawa, J.; Koyama, K. [Kyoto Univ., Faculty of Science, Kyoto (Japan)

    1999-08-01

    We present recent remarkable topics about discoveries of X-ray pulsars. 1. Pulsations from two Soft Gamma-ray Repeaters: These pulsars have enormously strong magnetic field (B {approx} 10{sup 15} G), thus these are called as 'magnetar', new type of X-ray pulsars. 2. New Crab-like pulsars: These discoveries lead to suggesting universality of Crab-like pulsars. 3. An X-ray bursting millisecond pulsar: This is strong evidence for the recycle theory of generating radio millisecond pulsars. 4. X-ray pulsar rush in the SMC: This indicates the younger star formation history in the SMC. (author)

  12. Heat loading limits for solid transuranic wastes storage

    Energy Technology Data Exchange (ETDEWEB)

    Spatz, T.L.

    1993-07-01

    Heat loading limits have been established for four storage configurations of TRU wastes. The calculations were performed assuming the worst case scenario whereby all the heat generated within a drum was generated within one ``cut`` and that this cut was located in the very center of the drum. Poly-boxes containing one HEPA filter were assumed to have a uniform heat generation throughout the filter. The maximum allowable temperatures were based on the materials in the containers. A comparison between the drum center temperature for a uniform heat load distribution and for the center temperature when the heat load is confined to one cut in the center of the drum is also illustrated. This comparison showed that the heat load of a particular drum can be more than doubled by distributing the sources of heat uniformly throughout the container.

  13. A Joint GMRT/X-ray study of galaxy groups

    CERN Document Server

    O'Sullivan, E; Vrtilek, J M; Raychaudhuri, S; Athreya, R; Venturi, T; David, L P

    2009-01-01

    We present results from combined low-frequency radio and X-ray studies of nearby galaxy groups. We consider two main areas: firstly, the evolutionary process from spiral-dominated, HI-rich groups to elliptical-dominated systems with hot, X-ray emitting gas halos; secondly, the mechanism of AGN feedback which appears to balance radiative cooling of the hot halos of evolved groups. The combination of radio and X-ray observations provides a powerful tool for these studies, allowing examination of gas in both hot and cool phases, and of the effects of shock heating and AGN outbursts. Low-frequency radio data are effective in detecting older and less energetic electron populations and are therefore vital for the determination of the energetics and history of such events. We present results from our ongoing study of Stephan's Quintet, a spiral-rich group in which tidal interactions and shock heating appear to be transforming HI in the galaxies into a diffuse X-ray emitting halo, and show examples of AGN feedback fr...

  14. Effect of Cobalt Fillers on Polyurethane Segmentations Investigated by Synchrotron Small Angle X-Ray Scattering

    Directory of Open Access Journals (Sweden)

    Krit Koyvanich

    2013-01-01

    Full Text Available The segmentation between rigid and rubbery chains in polyurethanes (PUs influences polymeric properties and implementations. Several models have successfully been proposed to visualize the configuration between the hard segment (HS and soft segment (SS. For particulate PU composites, the arrangement of HS and SS is more complicated because the fillers tend to disrupt the chain formation and segmentation. In this work, the effect of ferromagnetic cobalt (Co powders (average diameter 2 μm on PU synthesized from a reaction between polyether polyol (soft segment and diphenylmethane-4,4′-diisocyanate (hard segment was studied with varying loadings (0, 20, 40, and 60 wt.%. The 300 μm thick PU/Co samples were tape-casted and then received heat treatment at 80°C for 180 min. From synchrotron small angle X-ray scattering (SAXS, the plot of the X-ray scattering intensity (I against the scattering vector (q exhibited a typical single peak of PU whose intensity was reduced by the increase in the Co loading. Characteristic SAXS peaks in the case of 0-20 wt.% Co agreed well with the scattering by globular hard segment domains according to Zernike-Prins and Percus-Yevick models. The higher Co loadings led to larger deviations from all theoretical models.

  15. All the X-ray binaries in the Universe: X-ray Emission from Normal and Starburst Galaxies Near and Far

    Science.gov (United States)

    Hornschemeier, Ann; Basu-Zych, Antara; Lehmer, Bret

    2015-08-01

    There has recently been quite a bit of excitement on the role of X-ray emission from galaxies in early heating of the IGM, demonstrating that understanding of X-ray emission from normal and starburst galaxies may have significant impact on structure formation in the Universe. The X-ray output from X-ray binaries and hot gas are both important and may rival the ionizing output of AGN at z>5, particularly for Hydrogen reionization. Here we present our research on constraining the X-ray SED of galaxies across cosmic time via several complementary approaches. In the very local universe (d optical/UV surveys that may be studied with Chandra. We will finish with a discussion of starburst galaxies emitting X-rays at z>4, which thanks to the extremely deep Chandra Deep Field-South 7 Ms survey, are better constrained than ever before. We discuss survey strategy and how the various pieces of the puzzle fit together regarding the X-ray output of galaxies and their X-ray binary populations over cosmic time. We discuss implications for next-generation missions and instruments, including those with wide-field survey capabilities and high throughput, especially the Athena mission.

  16. Short-term heat load forecasting for single family houses

    DEFF Research Database (Denmark)

    Bacher, Peder; Madsen, Henrik; Nielsen, Henrik Aalborg;

    2013-01-01

    This paper presents a method for forecasting the load for space heating in a single-family house. The forecasting model is built using data from sixteen houses located in Sønderborg, Denmark, combined with local climate measurements and weather forecasts. Every hour the hourly heat load for each ...

  17. Muonic X-ray spectroscopy: Effect of the presence of protons on X-ray production

    National Research Council Canada - National Science Library

    Mohamadsalehi, F; Gheisari, R; Rahimi, N

    2016-01-01

    ... . The target has a high efficiency for analyzing characteristic X-rays in ion implantation. To predict the effect of the presence of protons on X-ray production, we have proposed a new kinetic schema...

  18. SMM X-ray polychromator

    Science.gov (United States)

    Strong, Keith T.; Haisch, Bernhard M. (Compiler); Lemen, James R. (Compiler); Acton, L. W.; Bawa, H. S.; Claflin, E. S.; Freeland, S. L.; Slater, G. L.; Kemp, D. L.; Linford, G. A.

    1988-01-01

    The range of observing and analysis programs accomplished with the X-Ray Polychromator (XRP) instruments during the decline of solar cycle 21 and the rise of the solar cycle 22 is summarized. Section 2 describes XRP operations and current status. This is meant as a guide on how the instrument is used to obtain data and what its capabilities are for potential users. The science section contains a series of representative abstracts from recently published papers on major XRP science topics. It is not meant to be a complete list but illustrates the type of science that can come from the analysis of the XRP data. There then follows a series of appendixes that summarize the major data bases that are available. Appendix A is a complete bibliography of papers and presentations produced using XRP data. Appendix B lists all the spectroscopic data accumulated by the Flat Crystal Spectrometer (FCS). Appendix C is a compilation of the XRP flare catalogue for events equivalent to a GOES C-level flare or greater. It lists the start, peak and end times as well as the peak Ca XIX flux.

  19. X-ray computed tomography

    Energy Technology Data Exchange (ETDEWEB)

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

    2006-07-07

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

  20. Synchrotron X-ray adaptative monochromator: study and realization of a prototype; Monochromateur adaptatif pour rayonnement X synchrotron: etude et realisation d`un prototype

    Energy Technology Data Exchange (ETDEWEB)

    Dezoret, D.

    1995-12-12

    This work presents a study of a prototype of a synchrotron X-ray monochromator. The spectral qualities of this optic are sensitive to the heat loads which are particularly important on third synchrotron generation like ESRF. Indeed, powers generated by synchrotron beams can reach few kilowatts and power densities about a few tens watts per square millimeters. The mechanical deformations of the optical elements of the beamlines issue issue of the heat load can damage their spectral efficiencies. In order to compensate the deformations, wa have been studying the transposition of the adaptive astronomical optics technology to the x-ray field. First, we have considered the modifications of the spectral characteristics of a crystal induced by x-rays. We have established the specifications required to a technological realisation. Then, thermomechanical and technological studies have been required to transpose the astronomical technology to an x-ray technology. After these studies, we have begun the realisation of a prototype. This monochromator is composed by a crystal of silicon (111) bonded on a piezo-electric structure. The mechanical control is a loop system composed by a infrared light, a Shack-Hartmann CDD and wave front analyser. This system has to compensate the deformations of the crystal in the 5 kcV to 60 kcV energy range with a power density of 1 watt per square millimeters. (authors).

  1. Diffraction leveraged modulation of X-ray pulses using MEMS-based X-ray optics

    Science.gov (United States)

    Lopez, Daniel; Shenoy, Gopal; Wang, Jin; Walko, Donald A.; Jung, Il-Woong; Mukhopadhyay, Deepkishore

    2016-08-09

    A method and apparatus are provided for implementing Bragg-diffraction leveraged modulation of X-ray pulses using MicroElectroMechanical systems (MEMS) based diffractive optics. An oscillating crystalline MEMS device generates a controllable time-window for diffraction of the incident X-ray radiation. The Bragg-diffraction leveraged modulation of X-ray pulses includes isolating a particular pulse, spatially separating individual pulses, and spreading a single pulse from an X-ray pulse-train.

  2. X-ray lasers: Multicolour emission

    Science.gov (United States)

    Feng, Chao; Deng, Haixiao

    2016-11-01

    The X-ray free-electron laser at the SLAC National Accelerator Laboratory in the US can now generate multicolour X-ray pulses with unprecedented brightness using the fresh-slice technique. The development opens the way to new forms of spectroscopy.

  3. X-Ray Detection Visits the Classroom

    Science.gov (United States)

    Peralta, Luis; Farinha, Ana; Pinto, Ana

    2008-01-01

    Film has been used to detect x-rays since the early days of their discovery by Rontgen. Although nowadays superseded by other techniques, film still provides a cheap means of x-ray detection, making it attractive in high-school or undergraduate university courses. If some sort of quantitative result is required, the film's optical absorbance or…

  4. Accelerator-driven X-ray Sources

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Dinh Cong [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-11-09

    After an introduction which mentions x-ray tubes and storage rings and gives a brief review of special relativity, the subject is treated under the following topics and subtopics: synchrotron radiation (bending magnet radiation, wiggler radiation, undulator radiation, brightness and brilliance definition, synchrotron radiation facilities), x-ray free-electron lasers (linac-driven X-ray FEL, FEL interactions, self-amplified spontaneous emission (SASE), SASE self-seeding, fourth-generation light source facilities), and other X-ray sources (energy recovery linacs, Inverse Compton scattering, laser wakefield accelerator driven X-ray sources. In summary, accelerator-based light sources cover the entire electromagnetic spectrum. Synchrotron radiation (bending magnet, wiggler and undulator radiation) has unique properties that can be tailored to the users’ needs: bending magnet and wiggler radiation is broadband, undulator radiation has narrow spectral lines. X-ray FELs are the brightest coherent X-ray sources with high photon flux, femtosecond pulses, full transverse coherence, partial temporal coherence (SASE), and narrow spectral lines with seeding techniques. New developments in electron accelerators and radiation production can potentially lead to more compact sources of coherent X-rays.

  5. X-rays, clumping and wind structures

    Science.gov (United States)

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

    2011-01-01

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

  6. Cryogenic imaging x-ray spectrometer

    NARCIS (Netherlands)

    Wiegerink, Remco J.; van Baar, J.J.J.; de Boer, J.H.; Ridder, M.L.; Bruijn, M.P.; Germeau, A.; Hoevers, H.F.C.

    2005-01-01

    A micro-calorimeter array consisting of superconducting transition-edge sensors is under development for the X-ray imaging spectrometer on board of ESA's XEUS (X-ray Evolving Universe Spectroscopy) mission. An array of 32 /spl times/ 32 pixels with a pixel size of 250 micron square is envisaged. So

  7. Low Energy X-Ray Diagnostics - 1981.

    Science.gov (United States)

    1981-01-01

    Filtering, and Scattering of Soft X-Rays by Mirrors Victor Rehn Michelson Laboratory, Physics Division Naval Weapons Center, China Lake, California...met with in K.Tregidgo, 18, 2003 (1979). the manufacture of X-ray optical components. In 32. W.P.Linnik, C. R. Acad. Sci. URSS ., 5, 210 (1933). general

  8. Strain measurement of pure titanium covered with soft tissue using X-ray diffraction.

    Science.gov (United States)

    Fujisaki, Kazuhiro; Tadano, Shigeru

    2010-03-01

    Measurement of the stress and strain applied to implants and bone tissue in the human body are important for fracture prediction and evaluations of implant adaptation. The strain of titanium (Ti) materials can be measuring by X-ray diffraction techniques. This study applied X-ray diffraction to the skin tissue-covered Ti. Characteristic X-rays of Mo Kalpha were used and the X-rays diffracted from the Ti were detected through the covering skin tissue. The X-ray absorption by skin tissue is large under the diffracted X-rays detected in low angles because the length of penetration depends on the angle of inclination, equal to the Bragg angle. The effects of skin tissue to detect the diffracted X-rays were investigated in the experiments. And the strain measurements were conducted under bending loads applied to the Ti specimen. The effect of skin tissue was absorption of X-rays as well as the X-rays scattered from the physiological saline contained in the tissue. The X-rays scattered by the physiological saline creates a specific background pattern near the peaks from the (002) and (011) lattice planes of Ti in the X-ray diffraction profile. Diffracted X-rays from the Ti were detected after being transmitted through 1 mm thick skin tissue by Mo Kalpha. Individual peaks such as (010), (002), (011), and (110) were clearly established by using a parallel beam arrangement. The strains of (110) lattice planes were measured with or without the tissue cover were very similar. The strain of the (110) lattice planes of Ti could be measured by Mo Kalpha when the Ti specimen was located under the skin tissue.

  9. The X-Ray View of OB Star Wind Structure and Dynamics

    Science.gov (United States)

    Cohen, D. H.

    2012-12-01

    High-resolution X-ray grating spectroscopy enables us to measure the kinematics and spatial distribution of the shock-heated wind plasma in O and early B stars, testing the predictions of the embedded wind shock scenario of massive star X-ray production. By fitting models to the resolved, Doppler broadened X-ray emission line profiles measured by the Chandra X-ray Observatory's grating spectrometer, we find an onset radius of X-ray production of roughly Ro = 1.5 R★ for the O supergiants, ζ Pup and HD 93129A. From the profile fitting we also find that the terminal velocity of the X-ray emitting plasma is consistent with that of the bulk, UV absorbing wind. We also use the X-ray emission line profiles to measure the wind mass-loss rates and break the degeneracy between mass-loss rate and clumping factor that affects traditional Hα and radio free-free diagnostics. We find clumping factors of order fcl = 10, which also agrees with the simulations of the wind instability. And we find that clumping begins very close to the photosphere, significantly lower in the wind than the onset of X-ray production. For lower density B star winds, the X-ray emission lines are much narrower than in the O supergiants, and are inconsistent with the hot plasma sharing the kinematics of the bulk wind.

  10. Perspectives of medical X-ray imaging

    Energy Technology Data Exchange (ETDEWEB)

    Freudenberger, J. E-mail: joerg.freudenberger@med.siemens.de; Hell, E.; Knuepfer, W

    2001-06-21

    While X-ray image intensifiers (XII), storage phosphor screens and film-screen systems are still the work horses of medical imaging, large flat panel solid state detectors using either scintillators and amorphous silicon photo diode arrays (FD-Si), or direct X-ray conversion in amorphous selenium are reaching maturity. The main advantage with respect to image quality and low patient dose of the XII and FD-Si systems is caused by the rise of the Detector Quantum Efficiency originating from the application of thick needle-structured phosphor X-ray absorbers. With the detectors getting closer to an optimal state, further progress in medical X-ray imaging requires an improvement of the usable source characteristics. The development of clinical monochromatic X-ray sources of high power would not only allow an improved contrast-to-dose ratio by allowing smaller average photon energies in applications but would also lead to new imaging techniques.

  11. Perspectives of medical X-ray imaging

    Science.gov (United States)

    Freudenberger, J.; Hell, E.; Knüpfer, W.

    2001-06-01

    While X-ray image intensifiers (XII), storage phosphor screens and film-screen systems are still the work horses of medical imaging, large flat panel solid state detectors using either scintillators and amorphous silicon photo diode arrays (FD-Si), or direct X-ray conversion in amorphous selenium are reaching maturity. The main advantage with respect to image quality and low patient dose of the XII and FD-Si systems is caused by the rise of the Detector Quantum Efficiency originating from the application of thick needle-structured phosphor X-ray absorbers. With the detectors getting closer to an optimal state, further progress in medical X-ray imaging requires an improvement of the usable source characteristics. The development of clinical monochromatic X-ray sources of high power would not only allow an improved contrast-to-dose ratio by allowing smaller average photon energies in applications but would also lead to new imaging techniques.

  12. An X-ray view of quasars

    CERN Document Server

    Singh, K P

    2013-01-01

    I present an overview of observational studies of quasars of all types, with particular emphasis on X-ray observational studies. The presentation is based on the most popularly accepted unified picture of quasars - collectively referred to as AGN (active galactic nuclei) in this review. Characteristics of X-ray spectra and X-ray variability obtained from various X-ray satellites over the last 5 decades have been presented and discussed. The contribution of AGN in understanding the cosmic X-ray background is discussed very briefly. Attempt has been made to provide up-to-date information; however, this is a vast subject and this presentation is not intended to be comprehensive.

  13. LOBSTER - New Space X-Ray telescopes

    Energy Technology Data Exchange (ETDEWEB)

    Hudec, R. [Astronomical Institute, Academy of Sciences of the Czech Republic, CZ-251 65 Ondrejov (Czech Republic); Pina, L. [Faculty of Nuclear Science, Czech Technical University, Prague (Czech Republic); Simon, V. [Astronomical Institute, Academy of Sciences of the Czech Republic, CZ-251 65 Ondrejov (Czech Republic); Sveda, L. [Faculty of Nuclear Science, Czech Technical University, Prague (Czech Republic); Inneman, A.; Semencova, V. [Center for Advanced X-ray Technologies, Reflex, Prague (Czech Republic); Skulinova, M. [Astronomical Institute, Academy of Sciences of the Czech Republic, CZ-251 65 Ondrejov (Czech Republic)

    2007-04-15

    We discuss the technological and scientific aspects of fully innovative very wide-field X-ray telescopes with high sensitivity. The prototypes of Lobster telescopes designed, developed and tested are very promising, allowing the proposals for space projects with very wide-field Lobster Eye X-ray optics to be considered for the first time. The novel telescopes will monitor the sky with unprecedented sensitivity and angular resolution of order of 1 arcmin. They are expected to contribute essentially to study of various astrophysical objects such as AGN, SNe, Gamma-ray bursts (GRBs), X-ray flashes (XRFs), galactic binary sources, stars, CVs, X-ray novae, various transient sources, etc. For example, the Lobster optics based X-ray All Sky Monitor is capable to detect around 20 GRBs and 8 XRFs yearly and this will surely significantly contribute to the related science.

  14. High Energy Vision: Processing X-rays

    CERN Document Server

    DePasquale, Joseph; Edmonds, Peter

    2015-01-01

    Astronomy is by nature a visual science. The high quality imagery produced by the world's observatories can be a key to effectively engaging with the public and helping to inspire the next generation of scientists. Creating compelling astronomical imagery can, however, be particularly challenging in the non-optical wavelength regimes. In the case of X-ray astronomy, where the amount of light available to create an image is severely limited, it is necessary to employ sophisticated image processing algorithms to translate light beyond human vision into imagery that is aesthetically pleasing while still being scientifically accurate. This paper provides a brief overview of the history of X-ray astronomy leading to the deployment of NASA's Chandra X-ray Observatory, followed by an examination of the specific challenges posed by processing X-ray imagery. The authors then explore image processing techniques used to mitigate such processing challenges in order to create effective public imagery for X-ray astronomy. ...

  15. Globular Cluster X-ray Sources

    CERN Document Server

    Verbunt, F

    2004-01-01

    After a brief historical overview we discuss the luminous X-ray sources in globular clusters of our Galaxy. This is followed by an overview of the very luminous X-ray sources studied in globular clusters of 14 other galaxies, and a discussion of their formation and the relation to X-ray sources outside globular clusters. We describe the discovery and classification of low-luminosity X-ray sources, and end the review with some remarks on the formation and evolution of X-ray sources in globular clusters. Observational results are summarized in three tables. Comments are very welcome. Please send them to F.W.M.Verbunt@astro.uu.nl and lewin@mit.edu.

  16. X-ray Fourier ptychographic microscopy

    CERN Document Server

    Simons, H; Guigay, J P; Detlefs, C

    2016-01-01

    Following the recent developement of Fourier ptychographic microscopy (FPM) in the visible range by Zheng et al. (2013), we propose an adaptation for hard x-rays. FPM employs ptychographic reconstruction to merge a series of low-resolution, wide field of view images into a high-resolution image. In the x-ray range this opens the possibility to overcome the limited numerical aperture of existing x-ray lenses. Furthermore, digital wave front correction (DWC) may be used to charaterize and correct lens imperfections. Given the diffraction limit achievable with x-ray lenses (below 100 nm), x-ray Fourier ptychographic microscopy (XFPM) should be able to reach resolutions in the 10 nm range.

  17. X-ray diffraction: instrumentation and applications.

    Science.gov (United States)

    Bunaciu, Andrei A; Udriştioiu, Elena Gabriela; Aboul-Enein, Hassan Y

    2015-01-01

    X-ray diffraction (XRD) is a powerful nondestructive technique for characterizing crystalline materials. It provides information on structures, phases, preferred crystal orientations (texture), and other structural parameters, such as average grain size, crystallinity, strain, and crystal defects. X-ray diffraction peaks are produced by constructive interference of a monochromatic beam of X-rays scattered at specific angles from each set of lattice planes in a sample. The peak intensities are determined by the distribution of atoms within the lattice. Consequently, the X-ray diffraction pattern is the fingerprint of periodic atomic arrangements in a given material. This review summarizes the scientific trends associated with the rapid development of the technique of X-ray diffraction over the past five years pertaining to the fields of pharmaceuticals, forensic science, geological applications, microelectronics, and glass manufacturing, as well as in corrosion analysis.

  18. X-ray modeling for SMILE

    Science.gov (United States)

    Sun, T.; Wang, C.; Wei, F.; Liu, Z. Q.; Zheng, J.; Yu, X. Z.; Sembay, S.; Branduardi-Raymont, G.

    2016-12-01

    SMILE (Solar wind Magnetosphere Ionosphere Link Explorer) is a novel mission to explore the coupling of the solar wind-magnetosphere-ionosphere system via providing global images of the magnetosphere and aurora. As the X-ray imaging is a brand new technique applied to study the large scale magnetopause, modeling of the solar wind charge exchange (SWCX) X-ray emissions in the magnetosheath and cusps is vital in various aspects: it helps the design of the Soft X-ray Imager (SXI) on SMILE, selection of satellite orbits, as well as the analysis of expected scientific outcomes. Based on the PPMLR-MHD code, we present the simulation results of the X-ray emissions in geospace during storm time. Both the polar orbit and the Molniya orbit are used. From the X-ray images of the magnetosheath and cusps, the magnetospheric responses to an interplanetary shock and IMF southward turning are analyzed.

  19. Characterizing automotive fuel cell materials by soft x-ray scanning transmission x-ray microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Hitchcock, A. P., E-mail: aph@mcmaster.ca; Lee, V.; Wu, J.; Cooper, G. [Chemistry & Chemical Biology, McMaster University, Hamilton, ON, L8S 4M1 (Canada); West, M. M.; Berejnov, V. [Faculty of Health Sciences Electron Microscopy, McMaster University, Hamilton, ON L8N 3Z5 (Canada); Soboleva, T.; Susac, D.; Stumper, J. [Automotive Fuel Cell Cooperation Corp., Burnaby BC V5J 5J8 (Canada)

    2016-01-28

    Proton-Exchange Membrane Fuel Cell (PEM-FC) based engines are being developed rapidly for near-term implementation in hydrogen fueled, mass production, personal automobiles. Research is focused on understanding and controlling various degradation processes (carbon corrosion, Pt migration, cold start), and reducing cost by reducing or eliminating Pt catalyst. We are using soft X-ray scanning transmission X-ray microscopy (STXM) at the S 2p, C 1s, O 1s and F 1s edges to study a variety of issues related to optimization of PEM-FC materials for automotive applications. A method to efficiently and accurately measure perfluorosulfonic acid distributions was developed and is being used to better understand how different loadings and preparation methods affect the ionomer distribution in the cathode. Progress towards an environmental cell capable of controlling the temperature and humidity of a PEM-FC sample in the STXM is described. Methods for studying the 3D chemical structure of PEM-FC are outlined.

  20. Characterizing automotive fuel cell materials by soft x-ray scanning transmission x-ray microscopy

    Science.gov (United States)

    Hitchcock, A. P.; Lee, V.; Wu, J.; West, M. M.; Cooper, G.; Berejnov, V.; Soboleva, T.; Susac, D.; Stumper, J.

    2016-01-01

    Proton-Exchange Membrane Fuel Cell (PEM-FC) based engines are being developed rapidly for near-term implementation in hydrogen fueled, mass production, personal automobiles. Research is focused on understanding and controlling various degradation processes (carbon corrosion, Pt migration, cold start), and reducing cost by reducing or eliminating Pt catalyst. We are using soft X-ray scanning transmission X-ray microscopy (STXM) at the S 2p, C 1s, O 1s and F 1s edges to study a variety of issues related to optimization of PEM-FC materials for automotive applications. A method to efficiently and accurately measure perfluorosulfonic acid distributions was developed and is being used to better understand how different loadings and preparation methods affect the ionomer distribution in the cathode. Progress towards an environmental cell capable of controlling the temperature and humidity of a PEM-FC sample in the STXM is described. Methods for studying the 3D chemical structure of PEM-FC are outlined.

  1. Hard X-ray mirrors for Nuclear Security

    Energy Technology Data Exchange (ETDEWEB)

    Descalle, M. A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Brejnholt, N. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Hill, R. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Decker, T. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Alameda, J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Soufli, R. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Pivovaroff, M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Pardini, T. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2016-01-07

    Research performed under this LDRD aimed to demonstrate the ability to detect and measure hard X-ray emissions using multilayer X-ray reflective optics above 400 keV, to enable the development of inexpensive and high-accuracy mirror substrates, and to investigate applications of hard X-ray mirrors of interest to the nuclear security community. Experiments conducted at the European Synchrotron Radiation Facility demonstrated hard X-ray mirror reflectivity up to 650 keV for the first time. Hard X-ray optics substrates must have surface roughness under 3 to 4 Angstrom rms, and three materials were evaluated as potential substrates: polycarbonates, thin Schott glass and a new type of flexible glass called Willow Glass®. Chemical smoothing and thermal heating of the surface of polycarbonate samples, which are inexpensive but have poor intrinsic surface characteristics, did not yield acceptable surface roughness. D263 Schott glass was used for the focusing optics of the NASA NuSTAR telescope. The required specialized hardware and process were costly and motivated experiments with a modified non-contact slumping technique. The surface roughness of the glass was preserved and the process yielded cylindrical shells with good net shape pointing to the potential advantage of this technique. Finally, measured surface roughness of 200 and 130 μm thick Willow Glass sheets was between 2 and 2.5 A rms. Additional results of flexibility tests and multilayer deposition campaigns indicated it is a promising substrate for hard X-ray optics. The detection of U and Pu characteristics X-ray lines and gamma emission lines in a high background environment was identified as an area for which X-ray mirrors could have an impact and where focusing optics could help reduce signal to noise ratio by focusing signal onto a smaller detector. Hence the first one twelvetant of a Wolter I focusing optics for the 90 to 140 keV energy range based on aperiodic multilayer coating was designed. Finally

  2. Analytical study of the heat loss attenuation by clothing on thermal manikins under radiative heat loads

    NARCIS (Netherlands)

    Hartog, E.A. den; Havenith, G.

    2010-01-01

    For wearers of protective clothing in radiation environments there are no quantitative guidelines available for the effect of a radiative heat load on heat exchange. Under the European Union funded project ThermProtect an analytical effort was defined to address the issue of radiative heat load whil

  3. iRadMat: A thermo-mechanical testing system for in situ high-energy X-ray characterization of radioactive specimens

    Science.gov (United States)

    Zhang, Xuan; Xu, Chi; Wang, Leyun; Chen, Yiren; Li, Meimei; Almer, Jonathan D.; Benda, Erika; Kenesei, Peter; Mashayekhi, Ali; Park, Jun-Sang; Westferro, Frank J.

    2017-01-01

    We present an in situ Radiated Materials (iRadMat) experimental module designed to interface with a servo-hydraulic load frame for X-ray measurements at beamline 1-ID at the Advanced Photon Source. This new capability allows in situ studies of radioactive specimens subject to thermo-mechanical loading using a suite of high-energy X-ray scattering and imaging techniques. The iRadMat is a radiation-shielded vacuum heating system with the sample rotation-under-load capability. We describe the design features and performances of the iRadMat and present a dataset from a 300 °C uniaxial tensile test of a neutron-irradiated pure Fe specimen to demonstrate its capabilities.

  4. First X-ray fluorescence CT experimental results at the SSRF X-ray imaging beamline

    Institute of Scientific and Technical Information of China (English)

    DENG Biao; YANG Qun; XIE Hong-Lan; DU Guo-Hao; XIAO Wi-Qiao

    2011-01-01

    X-ray fluorescence CT is a non-destructive technique for detecting elemental composition and distribution inside a specimen. In this paper, the first experimental results of X-ray fluorescence CT obtained at the SSRF X-ray imaging beamline (BL13W1) are described. The test samples were investigated and the 2D elemental image was reconstructed using a filtered back-projection algorithm. In the sample the element Cd was observed. Up to now, the X-ray fluorescence CT could be carried out at the SSRF X-ray imaging beamline.

  5. Soft X-Ray Observations of a Complete Sample of X-Ray--selected BL Lacertae Objects

    Science.gov (United States)

    Perlman, Eric S.; Stocke, John T.; Wang, Q. Daniel; Morris, Simon L.

    1996-01-01

    We present the results of ROSAT PSPC observations of the X-ray selected BL Lacertae objects (XBLs) in the complete Einstein Extended Medium Sensitivity Survey (EM MS) sample. None of the objects is resolved in their respective PSPC images, but all are easily detected. All BL Lac objects in this sample are well-fitted by single power laws. Their X-ray spectra exhibit a variety of spectral slopes, with best-fit energy power-law spectral indices between α = 0.5-2.3. The PSPC spectra of this sample are slightly steeper than those typical of flat ratio-spectrum quasars. Because almost all of the individual PSPC spectral indices are equal to or slightly steeper than the overall optical to X-ray spectral indices for these same objects, we infer that BL Lac soft X-ray continua are dominated by steep-spectrum synchrotron radiation from a broad X-ray jet, rather than flat-spectrum inverse Compton radiation linked to the narrower radio/millimeter jet. The softness of the X-ray spectra of these XBLs revives the possibility proposed by Guilbert, Fabian, & McCray (1983) that BL Lac objects are lineless because the circumnuclear gas cannot be heated sufficiently to permit two stable gas phases, the cooler of which would comprise the broad emission-line clouds. Because unified schemes predict that hard self-Compton radiation is beamed only into a small solid angle in BL Lac objects, the steep-spectrum synchrotron tail controls the temperature of the circumnuclear gas at r ≤ 1018 cm and prevents broad-line cloud formation. We use these new ROSAT data to recalculate the X-ray luminosity function and cosmological evolution of the complete EMSS sample by determining accurate K-corrections for the sample and estimating the effects of variability and the possibility of incompleteness in the sample. Our analysis confirms that XBLs are evolving "negatively," opposite in sense to quasars, with Ve/Va = 0.331±0.060. The statistically significant difference between the values for X-ray

  6. The Herbig Ae star HD 163296 in X-rays

    CERN Document Server

    Swartz, D A; Elsner, R F; Ghosh, K K; Grady, C A; Wassell, E; Woodgate, B E; Kimble, R A; Swartz, Douglas A.; Drake, Jeremy J.; Elsner, Ronald F.; Ghosh, Kajal K.; Grady, Carol A.; Wassell, Edward; Woodgate, Bruce E.; Kimble, Randy A.

    2005-01-01

    Chandra X-ray imaging spectroscopy of the nearby Herbig Ae star HD 163296 at 100 AU angular resolution is reported. A point-like, soft (kT~0.5 keV), emission-line source is detected at the location of the star with an X-ray luminosity of 4.0e29 erg/s. In addition, faint emission along the direction of a previously-detected Ly-alpha-emitting jet and Herbig-Haro outflow may be present. The relatively low luminosity, lack of a hard spectral component, and absence of strong X-ray variability in HD 163296 can be explained as originating from optically-thin shock-heated gas accreting onto the stellar surface along magnetic field lines. This would require a (dipole) magnetic field strength at the surface of HD 163296 of at least ~100 G and perhaps as high as several kG. HD 163296 joins the T Tauri star TW Hya in being the only examples known to date of pre-main-sequence stars whose quiescent X-ray emission appears to be completely dominated by accretion.

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

    Science.gov (United States)

    Robinson, Ian; Gruebel, Gerhard; Mochrie, Simon

    2010-03-01

    Williams, H M Quiney, A G Peele and K A Nugent Imaging of complex density in silver nanocubes by coherent x-ray diffraction R Harder, M Liang, Y Sun, Y Xia and I K Robinson Methodology for studying strain inhomogeneities in polycrystalline thin films during in situ thermal loading using coherent x-ray diffraction N Vaxelaire, H Proudhon, S Labat, C Kirchlechner, J Keckes, V Jacques, S Ravy, S Forest and O Thomas Ptychographic coherent diffractive imaging of weakly scattering specimens Martin Dierolf, Pierre Thibault, Andreas Menzel, Cameron M Kewish, Konstantins Jefimovs, Ilme Schlichting, Konstanze von König, Oliver Bunk and Franz Pfeiffer Dose requirements for resolving a given feature in an object by coherent x-ray diffraction imaging Andreas Schropp and Christian G Schroer FLASH: new opportunities for (time-resolved) coherent imaging of nanostructures R Treusch and J Feldhaus Structure of a single particle from scattering by many particles randomly oriented about an axis: toward structure solution without crystallization? D K Saldin, V L Shneerson, M R Howells, S Marchesini, H N Chapman, M Bogan, D Shapiro, R A Kirian, U Weierstall, K E Schmidt and J C H Spence Analysis of strain and stacking faults in single nanowires using Bragg coherent diffraction imaging V Favre-Nicolin, F Mastropietro, J Eymery, D Camacho, Y M Niquet, B M Borg, M E Messing, L-E Wernersson, R E Algra, E P A M Bakkers, T H Metzger, R Harder and I K Robinson Coherent science at the SwissFEL x-ray laser B D Patterson, R Abela, H-H Braun, U Flechsig, R Ganter, Y Kim, E Kirk, A Oppelt, M Pedrozzi, S Reiche, L Rivkin, Th Schmidt, B Schmitt, V N Strocov, S Tsujino and A F Wrulich Energy recovery linac (ERL) coherent hard x-ray sources Donald H Bilderback, Joel D Brock, Darren S Dale, Kenneth D Finkelstein, Mark A Pfeifer and Sol M Gruner Statistical and coherence properties of radiation from x-ray free-electron lasers E L Saldin, E A Schneidmiller and M V Yurkov Microscopic return point memory in Co

  8. X-ray Ross filter method for impurity transport studies on DIII-D (abstract)

    Science.gov (United States)

    Bogatu, I. N.; Kim, J. S.; Egdell, D. H.; Snider, R. T.; Brooks, N. H.; Wade, M. R.; West, W. P.

    2001-01-01

    The injection of Ar into the region of the DIII-D divertor is a promising technique for energy dissipation (through radiation and collisions) and consequently for reduction of the heat load on the plates. An important problem related to this technique, is the inherent poisoning of the core plasma by migrating Ar. The Ar core contamination seems also to improve the thermal transport in an advanced operating mode of the tokamak. It is therefore of great importance to measure the evolution of the impurity concentration profile within the core plasma. This goal could be achieved by using the Ross filter method in conjunction with the existing x-ray diagnostics on DIII-D. A basic Ross filter system consists of two identical detectors placed behind two different x-ray absorbing foils looking at the same plasma volume. The foils are made of different elements or compounds with adjacent or nearly adjacent atomic numbers. Their accurate thickness causes the x-ray transmission curves of the two foils to be effectively identical over the entire energy range except within the narrow region between their absorption edges. Since the transmission characteristics of the foils above and below their absorption edges are the same, any difference in the two detected signals is proportional to the total x-ray power of the emission spectrum between these two edge energies. An x-ray Ross filter with its energy pass band centered on the Ar XVII Kα line at 3.14 keV has been designed. This allows for the discrimination of the Ar Kα line only, regardless of Ar ionization state, against any background radiation with energies outside the energy pass band. The Ross filter was installed in front of two of the fan shaped poloidal x-ray arrays on DIII-D. The first measurements showed very good discrimination against Ne, another injected impurity. Emissivity profile evolution of the Kα lines and Ar enhanced continuum within the energy pass band of the Ross filter can be determined from the x-ray

  9. X-ray in Zeta-Ori

    Science.gov (United States)

    López-García, M. A.; López-Santiago, J. L.; Albacete-Colombo, J. F.; De Castro, E.

    2013-05-01

    Nearby star-forming regions are ideal laboratories to study high-energy emission processes but they usually present high absorption what makes difficult to detect the stellar population inside the molecular complex. As young late-type stars show high X-ray emission and X-ray photons are little absorbed by interstellar material, X-ray dedicated surveys are an excellent tool to detect the low-mass stellar population in optically absorbed regions. In this work, we present a study of the star-forming region Zeta-Ori and its surroundings. We combine optical, infrared and X-ray data. Properties of the X-ray emiting plasma and infrared features of the young stellar objects detected in the XMM-Newton observation are determined. The southern part of the Orion B giant molecular cloud complex harbor other star forming regions, as NGC 2023 and NGC 2024, we use this regions to compare. We study the spectral energy distribution of X-ray sources. Combining these results with infrared, the X-ray sources are classified as class I, class II and class III objects. The X-ray spectrum and ligth curve of detected X-ray sources is analyzed to found flares. We use a extincion-independent index to select the stars with circumstellar disk, and study the relationship between the present of disk and the flare energy. The results are similar to others studies and we conclude that the coronal properties of class II and class III objects in this region do not differ significantly from each other and from stars of similar infrared class in the ONC.

  10. X-ray lattice strain determination in surface layers

    DEFF Research Database (Denmark)

    Somers, Marcel A.J.; Pantleon, Karen

    2002-01-01

    The present article describes several aspects of lattice strain determination in surface layers by means of X-ray diffraction analysis. Several possibilities and the origins of stress in surface layers are illustrated by the following three cases: 200 nm thick Mo layers on glass substrates; 5.5 m.......5 microns thick TiN layers on heat treatable steel and 21 microns thick gamma prime-Fe4N1-x layers on iron....

  11. X-ray and radio emission from colliding stellar winds

    CERN Document Server

    Pittard, J M; Coker, R F; Corcoran, M F

    2004-01-01

    The collision of the hypersonic winds in early-type binaries produces shock heated gas, which radiates thermal X-ray emission, and relativistic electrons, which emit nonthermal radio emission. We review our current understanding of the emission in these spectral regions and discuss models which have been developed for the interpretation of this emission. Physical processes which affect the resulting emission are reviewed and ideas for the future are noted.

  12. Flight model performance test results of a helium dewar for the soft X-ray spectrometer onboard ASTRO-H

    Science.gov (United States)

    Yoshida, Seiji; Miyaoka, Mikio; Kanao, Ken'ichi; Tsunematsu, Shoji; Otsuka, Kiyomi; Hoshika, Shunji; Mitsuda, Kazuhisa; Yamasaki, Noriko; Takei, Yoh; Fujimoto, Ryuichi; Sato, Yoichi; DiPirro, Mike; Shirron, Peter

    2016-03-01

    ASTRO-H is a Japanese X-ray astronomy satellite, scheduled to be launched in fiscal year 2015. The mission includes a soft X-ray spectrometer instrument (SXS), which contains an X-ray micro calorimeter operating at 50 mK by using an adiabatic demagnetization refrigerator (ADR). The heat sink of the ADR is superfluid liquid helium below 1.3 K. The required lifetime of the superfluid helium is 3 years or more. In order to realize this lifetime, we have improved the thermal performance from the engineering model (EM) while maintaining the mechanical performance. Then, we have performed a thermal test of the flight model (FM). The results were that the heat load to the helium tank was reduced to below 0.8 mW in the FM from 1.2 mW in the EM. Therefore, the lifetime of the superfluid helium is more than 3 years with 30 L of liquid helium. In this paper, the thermal design and thermal test results are described.

  13. X-ray phase-contrast methods

    Energy Technology Data Exchange (ETDEWEB)

    Lider, V. V., E-mail: lider@ns.crys.ras.ru; Kovalchuk, M. V. [Russian Academy of Sciences, Shubnikov Institute of Crystallography (Russian Federation)

    2013-11-15

    This review is devoted to a comparative description of the methods for forming X-ray phase-contrast images of weakly absorbing (phase) objects. These include the crystal interferometer method, the Talbot interferometer method, diffraction-enhanced X-ray imaging, and the in-line method. The potential of their practical application in various fields of science and technology is discussed. The publications on the development and optimization of X-ray phase-contrast methods and the experimental study of phase objects are analyzed.

  14. Two-dimensional x-ray diffraction

    CERN Document Server

    He, Bob B

    2009-01-01

    Written by one of the pioneers of 2D X-Ray Diffraction, this useful guide covers the fundamentals, experimental methods and applications of two-dimensional x-ray diffraction, including geometry convention, x-ray source and optics, two-dimensional detectors, diffraction data interpretation, and configurations for various applications, such as phase identification, texture, stress, microstructure analysis, crystallinity, thin film analysis and combinatorial screening. Experimental examples in materials research, pharmaceuticals, and forensics are also given. This presents a key resource to resea

  15. A Burst Chasing X-ray Polarimeter

    Science.gov (United States)

    Hill, Joanne

    2007-01-01

    This viewgraph presentation reviews the rationale, design, and importance of an X-Ray Polarimeter. There is a brief discussion of Gamma Ray Bursts, followed by a review of the theories of Gamma-Ray Bursts Polarization. This leads to the question of "How do we measure the polarization?" and a discussion of the GRB x-ray emission, the photoelectric effect and photoelectric polarimetry. The requirements for the work, can only be approached using a gas detector. This leads to a discussion of a Micropattern Gas Polarimeter, and the Time-Projection Chamber (TPC) X-ray Polarimeter.

  16. Speckle Scanning Based X-ray Imaging

    CERN Document Server

    Berujon, Sebastien

    2015-01-01

    The X-ray near field speckle scanning concept is an approach recently introduced to obtain absorption, phase and darkfield images of a sample. In this paper, we demonstrate ways of recovering from a sample its ultra-small angle X-ray scattering distribution using numerical deconvolution, and the 2D phase gradient signal from random step scans, the latter being used to elude the flat field correction error. Each feature is explained theoretically and demonstrated experimentally at a synchrotron X-ray facility.

  17. Soft X-Ray Laser Development

    Science.gov (United States)

    1989-10-01

    AND SUBTrI 5. FUNDING NUMBERS Soft X-ray Laser Development 61102F/2301/A8 L AUTHOR(S) ( Szymon Suckewer 7. PERFORMING ORGANIZATION NAME(S) AND ADORESS...REPORT Report of Progress on Soft X-ray Laser Development submitted to Air Force Office of Scientific Research by Acession For DT!C T.IB Princeton...x-ray laser development by Jaegl6 and coworkers 6, however the present work on aluminium plasmas pumped with a low energy Nd laser was primarily

  18. The Future of X-Ray Optics

    Science.gov (United States)

    Weisskopf, Martin C.

    2013-01-01

    The most important next step is the development of X-ray optics comparable to (or better than) Chandra in angular resolution that far exceed Chandra s effective area. Use the long delay to establish an adequately funded, competitive technology program along the lines I have recommended. Don't be diverted from this objective, except for Explorer-class missions. Progress in X-ray optics, with emphasis on the angular resolution, is central to the paradigm-shifting discoveries and the contributions of X-ray astronomy to multiwavelength astrophysics over the past 51 years.

  19. X-rays from Alpha Centauri

    Science.gov (United States)

    Nugent, J.; Garmire, G.

    1978-01-01

    HEAO 1 observations of soft X-ray emission from a point source in the vicinity of Alpha Cen are reported. The source, designated H1437-61, is tentatively identified with Alpha Cen, and an X-ray luminosity comparable to that of the sun in an active state is estimated. A temperature of about 500,000 K and an emission integral of 5 x 10 to the 50th per cu cm are obtained. Coronal emission is suggested as the X-ray-producing mechanism.

  20. Optics for coherent X-ray applications

    OpenAIRE

    2014-01-01

    Developments of X-ray optics for full utilization of diffraction-limited storage rings (DLSRs) are presented. The expected performance of DLSRs is introduced using the design parameters of SPring-8 II. To develop optical elements applicable to manipulation of coherent X-rays, advanced technologies on precise processing and metrology were invented. With propagation-based coherent X-rays at the 1 km beamline of SPring-8, a beryllium window fabricated with the physical-vapour-deposition method w...

  1. Progress report on the Astro-H Soft X-Ray Spectrometer

    Science.gov (United States)

    Kelley, Richard L.; Mitsuda, Kazuhisa

    2016-04-01

    We describe the initial in-orbit operations and performance of the Astro-H Soft X-Ray Spectrometer (SXS). Astro-H, JAXA's sixth X-ray observatory, is scheduled for launch on February 12, 2016, from the Tanegashima Space Center in Japan abord an H-IIA rocket. The instrument is based on a 36-pixel array of microcalorimeters designed for high resolution over the 0.3-12 keV energy band at the focus of a high throughput, grazing-incidence x-ray mirror. The instrument is the result of a joint collaboration between the JAXA Institute of Space and Astronautical Science and many partners in Japan, and the NASA/Goddard Space Flight Center and collaborators in the US. The principal components of the spectrometer are the microcalorimeter detector system, a low-temperature anticoincidence detector, a 3-stage adiabatic demagnetization refrigerator (ADR) to maintain 50 mK operation under both cryogen and cryogen-free operation, a hybrid liquid helium/cryogen-free dewar with both Stirling and Joule-Thomson coolers, electronics for reading out the array, processing the x-ray data for spectroscopy, and operating the ADR and cryocoolers. The dewar is closed out by an aperture system with five thin-film filters designed to provide high x-ray transmission with low heat loads to the dewar and detector system, and prevent contamination from condensing on the filters. The instrument was designed to have better than 7 eV energy resolution, and was demonstrated to achieve 4-5 eV resolution across the array at the full spacecraft level of integration during extensive ground testing prior to launch. The overall cooling chain has been designed to provide a lifetime of at least 3 years in orbit, and continue to operate without liquid helium to provide redundancy and the longest operational lifetime for the instrument. In this presentation, we will describe the early phases of the SXS instrument in orbit and provide a sense of the astronomical results that can be expected. This presentation is

  2. Two methods for studying the X-ray variability

    NARCIS (Netherlands)

    Yan, Shu-Ping; Ji, Li; Méndez, Mariano; Wang, Na; Liu, Siming; Li, Xiang-Dong

    2016-01-01

    The X-ray aperiodic variability and quasi-periodic oscillation (QPO) are the important tools to study the structure of the accretion flow of X-ray binaries. However, the origin of the complex X-ray variability from X-ray binaries remains yet unsolved. We proposed two methods for studying the X-ray

  3. Transient behavior of heat pipe with thermal energy storage under pulse heat loads

    Science.gov (United States)

    Chang, Ming-, Jr.

    1991-02-01

    Future space missions will require thermal transport devices with the ability to handle transient pulse heat loads. A novel design of a high-temperature axially grooved heat pipe (HP) which incorporates thermal energy storage (TES) to migrate pulse heat loads was presented. A phase-change material (PCM) which is encapsulated in cylindrical containers was used for the thermal energy storage. The transient response of the HP/TES system under two different types of pulse heat loads was studied analytically. The first type is pulse heat loads applied at the heat pipe evaporator, the second type is reversed-pulse heat loads applied at the condenser. In this research, a new three-dimensional alternating-direction-implicit (ADI) method was developed to model the heat conduction through the heat pipe wall and wicks, including the liquid flow in grooves. A very important characteristic of this new ADI method is that it is consistent with physical considerations. Compared with the well-known Brian's and Douglas's ADI methods, this new ADI method had higher accuracy and requires less computer storage. In the numerical solution of heat transfer problems with phase change (Stefan-type problem), a modified Pham's method which includes features from enthalpy and heat capacity methods was used to simulate the melting and solidification processes of the PCG. The vapor flow was assumed quasi-steady and one-dimensional, and was coupled with the evaporation and condensation on the heat pipe inside wall surface and the surfaces of the PCM containers. The transient responses of three different HP/TES configurations were compared: (1) a heat pipe with a large empty cylinder installed in the vapor core, (2) a heat pipe with a large PCM cylinder, and (3) a heat pipe with six small PCM cylinders. From the numerical results, it was found that the PCM is very effective in mitigrating the adverse effect of pulse heat loads. The six small PCM cylinders are more efficient than the large PCM

  4. Demonstration of X-ray Thomson Scattering on Shenguang-Ⅱ Laser Facility

    Institute of Scientific and Technical Information of China (English)

    胡广月; 张小丁; 郑坚; 雷安乐; 沈百飞; 徐至展; 张继彦; 杨家敏; 杨国洪; 韦敏习; 李军; 丁永坤

    2012-01-01

    X-ray Thomson scattering technique for diagnosing dense plasma was demonstrated on Shenguang-Ⅱ laser facility. Laser plasma x-ray source of titanium He-a lines (-4.75 keV), generated by laser beam (1.5 kJ/527 nm/2 ns) heated titanium thin foil, was used as x-ray probe beam. The x-ray probe was then scattered by cold CH foam column of 1 g/cm^3 density. The scattered radiation at 90° was diffracted by polyethylene terephthalate (PET) crystal and recorded on x-ray charge-coupled device. Well-defined scattering spectra were obtained with good signal to noise ratio.

  5. Formation of X-ray emitting stationary shocks in magnetized protostellar jets

    CERN Document Server

    Ustamujic, S; Bonito, R; Miceli, M; de Castro, A I Gómez; López-Santiago, J

    2016-01-01

    X-ray observations of protostellar jets show evidence of strong shocks heating the plasma up to temperatures of a few million degrees. In some cases, the shocked features appear to be stationary. They are interpreted as shock diamonds. We aim at investigating the physics that guides the formation of X-ray emitting stationary shocks in protostellar jets, the role of the magnetic field in determining the location, stability, and detectability in X-rays of these shocks, and the physical properties of the shocked plasma. We performed a set of 2.5-dimensional magnetohydrodynamic numerical simulations modelling supersonic jets ramming into a magnetized medium and explored different configurations of the magnetic field. The model takes into account the most relevant physical effects, namely thermal conduction and radiative losses. We compared the model results with observations, via the emission measure and the X-ray luminosity synthesized from the simulations. Our model explains the formation of X-ray emitting stat...

  6. X-rays of IC443 - remnant of Tang dynasty supernova.

    Science.gov (United States)

    Wang, Zhenru

    Hard X-rays with energies up to 20 keV were observed from IC443 by the X-ray satellite Ginga. The X-ray flux below 6 keV is found consistent with that of earlier observations with Einstein and HEAO 1, and the X-ray spectrum smoothly extends to 20 keV. The feature of Fe K line is not conspicuous; an upper limit of the equivalent width for its emission is 250 eV. It is likely that the hard X-rays are emitted from a shock-heated plasma with a temperature higher than 10 keV and a number density smaller than 0.1 cm-3 which is probably located in the SW and W regions of IC443. This model predicts the age of IC443 to be about 1000 years. It is suggested that IC443 is the remnant of a supernova in AD 837.

  7. Soft X-ray Properties of Ultraluminous IRAS Galaxies

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    We report on the results of cross-correlation of a sample of 903 Ultra luminous IRAS galaxies (ULIRGs) with the ROSAT-All Sky Survey Bright Source Catalogue and the ROSAT archived pointing observations. The sample of ULIRGs has been compiled from the recently released PSCz redshift survey. In total, 35 ULIRGs are securely detected by the ROSAT All-Sky Survey and pointing observa tions, five of which are blazars. The statistical properties of these sources in the soft X-ray band are determined and compared with their properties in other wavebands. We find that the ratio of the soft X-ray to the far-infrared flux spans about five orders of magnitude and reaches values of about unity. This ratio is a good indi cator of the main energy source of ULIRGs. Those with soft X-ray to far-infrared flux exceeding 0.01 are probably powered by accretion onto central supermassive black holes while those with ratios smaller than 0.001 are probably powered by starbursts or other heating processes, or are Compton thick sources. Some ULIRGs have energy contributions from both. This ratio is low for most ULIRGs and hy perluminous infrared galaxies, which explains their low detection rate by ROSAT and ASCA. We also find that some ULIRGs have a similar soft X-ray luminosity vs. temperature relation to that for groups of galaxies and elliptical galaxies, suggest ing a common origin of these systems. Our study also reveals a tight correlation between the hardness ratio and the soft X-ray luminosity for Seyfert ls/QSOs.

  8. X-ray impact on the protoplanetary disks around T Tauri stars

    CERN Document Server

    Aresu, G; Meijerink, R; Woitke, P; Thi, W -F; Spaans, M

    2010-01-01

    Context: T Tauri stars have X-ray luminosities ranging from $L_{\\rm X} = 10^{28}-10^{32}\\,\\mathrm{erg\\,s^{-1}}$. These luminosities are similar to UV luminosities ($L_{\\rm UV} \\sim 10^{30}-10^{31} \\rm erg\\,s^{-1}$) and therefore X-rays are expected to affect the physics and chemistry of the upper layers of their surrounding protoplanetary disks. Aim: The effects and importance of X-rays on the chemical and hydrostatic structure of protoplanetary disks are investigated, species tracing X-ray irradiation (for $L_{\\rm X} \\geq 10^{29}\\mathrm{erg \\,s^{-1}}$) are identified and predictions for [O\\,{\\sc i}], [C\\,{\\sc ii}] and [N\\,{\\sc ii}] fine structure line fluxes are provided. Methods: We have implemented X-ray physics and chemistry into the chemo-physical disk code ProDiMo. We include Coulomb heating and $\\mathrm{H_2}$ ionization as heating processes and primary and secondary ionization due to X-rays in the chemistry. Results: X-rays heat up the gas causing it to expand in the optically thin surface layers. Neut...

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

    Science.gov (United States)

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

    2015-03-01

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

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

    Directory of Open Access Journals (Sweden)

    L. Miaja-Avila

    2015-03-01

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

  11. Milli X-Ray Fluorescence Spectrometer

    Data.gov (United States)

    Federal Laboratory Consortium — The Eagle III Micro XRF unit is similar to a traditional XRF unit, with the primary difference being that the X-rays are focused by a polycapillary optic into a spot...

  12. Silicon Wafer X-ray Mirror Project

    Data.gov (United States)

    National Aeronautics and Space Administration — In this one year research project, we propose to do the following four tasks;(1) Design the silicon wafer X-ray mirror demo unit and develop a ray-tracing code to...

  13. Nonrelativistic quantum X-ray physics

    CERN Document Server

    Hau-Riege, Stefan P

    2015-01-01

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

  14. The Need for X-Ray Spectroscopy

    Science.gov (United States)

    Winebarger, Amy R.; Cirtain, Jonathan; Kobayashi, Ken

    2011-01-01

    For over four decades, X-ray, EUV, and UV spectral observations have been used to measure physical properties of the solar atmosphere. During this time, there has been substantial improvement in the spectral, spatial, and temporal resolution of the observations for the EUV and UV wavelength ranges. At wavelengths below 100 Angstroms, however, observations of the solar corona with simultaneous spatial and spectral resolution are limited, and not since the late 1970's have spatially resolved solar X-ray spectra been measured. The soft-X-ray wavelength range is dominated by emission lines formed at high temperatures and provides diagnostics unavailable in any other wavelength range. In this presentation, we will discuss the important science questions that can be answered using spatially and spectrally resolved X-ray spectra.

  15. Cold X-Ray Impulse Estimates

    Energy Technology Data Exchange (ETDEWEB)

    DiPeso, G.

    2001-03-01

    The purpose of this short note is to document comparisons between a simple analytic model and the BUCKL[1]x-ray deposition and impulse code and to briefly demonstrate the effect of deposition time on impulse.

  16. Demonstration of X-ray talbot interferometry

    CERN Document Server

    Momose, A; Kawamoto, S; Hamaishi, Y; Takai, K; Suzuki, Y

    2003-01-01

    First Talbot interferometry in the hard X-ray region was demonstrated using a pair of transmission gratings made by forming gold stripes on glass plates. By aligning the gratings on the optical axis of X-rays with a separation that caused the Talbot effect by the first grating, moire fringes were produced inclining one grating slightly against the other around the optical axis. A phase object placed in front of the first grating was detected by moire-fringe bending. Using the technique of phase-shifting interferometry, the differential phase corresponding to the phase object could also be measured. This result suggests that X-ray Talbot interferometry is a novel and simple method for phase-sensitive X-ray radiography. (author)

  17. X-ray crystallographic studies of metalloproteins.

    Science.gov (United States)

    Volbeda, Anne

    2014-01-01

    Many proteins require metals for their physiological function. In combination with spectroscopic characterizations, X-ray crystallography is a very powerful method to correlate the function of protein-bound metal sites with their structure. Due to their special X-ray scattering properties, specific metals may be located in metalloprotein structures and eventually used for phasing the diffracted X-rays by the method of Multi-wavelength Anomalous Dispersion (MAD). How this is done is the principle subject of this chapter. Attention is also given to the crystallographic characterization of different oxidation states of redox active metals and to the complication of structural changes that may be induced by X-ray irradiation of protein crystals.

  18. Experimental x-ray ghost imaging

    CERN Document Server

    Pelliccia, Daniele; Scheel, Mario; Cantelli, Valentina; Paganin, David M

    2016-01-01

    We report an experimental proof of principle for ghost imaging in the hard x-ray energy range. We used a synchrotron x-ray beam that was split using a thin crystal in Laue diffraction geometry. With an ultra-fast imaging camera, we were able to image x-rays generated by isolated electron bunches. At this time scale, the shot noise of the synchrotron emission process is measurable as speckles, leading to speckle correlation between the two beams. The integrated transmitted intensity from a sample located in the first beam was correlated with the spatially resolved intensity measured on the second, empty, beam to retrieve the shadow of the sample. The demonstration of ghost imaging with hard x-rays may open the way to protocols to reduce radiation damage in medical imaging and in non-destructive structural characterization using Free Electron Lasers.

  19. X-ray source for mammography

    Science.gov (United States)

    Logan, Clinton M.

    1994-01-01

    An x-ray source utilizing anode material which shifts the output spectrum to higher energy and thereby obtains higher penetrating ability for screening mammography application, than the currently utilized anode material. The currently used anode material (molybdenum) produces an energy x-ray spectrum of 17.5/19.6 keV, which using the anode material of this invention (e.g. silver, rhodium, and tungsten) the x-ray spectrum would be in the 20-35 keV region. Thus, the anode material of this invention provides for imaging of breasts with higher than average x-ray opacity without increase of the radiation dose, and thus reduces the risk of induced breast cancer due to the radiation dose administered for mammograms.

  20. Astrophysics: Unexpected X-ray flares

    Science.gov (United States)

    Campana, Sergio

    2016-10-01

    Two sources of highly energetic flares have been discovered in archival X-ray data of 70 nearby galaxies. These flares have an undetermined origin and might represent previously unknown astrophysical phenomena. See Letter p.356

  1. X-ray induced optical reflectivity

    Directory of Open Access Journals (Sweden)

    Stephen M. Durbin

    2012-12-01

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

  2. Experimental X-Ray Ghost Imaging

    Science.gov (United States)

    Pelliccia, Daniele; Rack, Alexander; Scheel, Mario; Cantelli, Valentina; Paganin, David M.

    2016-09-01

    We report an experimental proof of principle for ghost imaging in the hard-x-ray energy range. We use a synchrotron x-ray beam that is split using a thin crystal in Laue diffraction geometry. With an ultrafast imaging camera, we are able to image x rays generated by isolated electron bunches. At this time scale, the shot noise of the synchrotron emission process is measurable as speckles, leading to speckle correlation between the two beams. The integrated transmitted intensity from a sample located in the first beam is correlated with the spatially resolved intensity measured in the second, empty, beam to retrieve the shadow of the sample. The demonstration of ghost imaging with hard x rays may open the way to protocols to reduce radiation damage in medical imaging and in nondestructive structural characterization using free electron lasers.

  3. Center for X-ray Optics (CXRO)

    Data.gov (United States)

    Federal Laboratory Consortium — The Center for X-Ray Optics at Lawrence Berkeley National Laboratory works to further science and technology using short wavelength optical systems and techniques....

  4. Silicon Wafer X-ray Mirror Project

    Data.gov (United States)

    National Aeronautics and Space Administration — In this one year research project, we propose to do the following four tasks; (1) Design the silicon wafer X-ray mirror demo unit and develop a ray-tracing code to...

  5. Capillary Optics generate stronger X-rays

    Science.gov (United States)

    1996-01-01

    NASA scientist, in the Space Sciences lab at Marshall, works with capillary optics that generate more intense X-rays than conventional sources. This capability is useful in studying the structure of important proteins.

  6. X-Ray Exam: Cervical Spine

    Science.gov (United States)

    ... the bones in the back of the neck (cervical vertebrae). During the examination, an X-ray machine sends ... or hand. It can detect fractures in the cervical vertebrae or dislocation of the joints between the vertebrae. ...

  7. Tuberculosis, advanced - chest x-rays (image)

    Science.gov (United States)

    Tuberculosis is an infectious disease that causes inflammation, the formation of tubercules and other growths within tissue, ... death. These chest x-rays show advanced pulmonary tuberculosis. There are multiple light areas (opacities) of varying ...

  8. X-ray microtomography in biology

    CERN Document Server

    Mizutani, Ryuta

    2016-01-01

    Progress in high-resolution x-ray microtomography has provided us with a practical approach to determining three-dimensional (3D) structures of opaque samples at micrometer to submicrometer resolution. In this review, we give an introduction to hard x-ray microtomography and its application to the visualization of 3D structures of biological soft tissues. Practical aspects of sample preparation, handling, data collection, 3D reconstruction, and structure analysis are described. Furthermore, different sample contrasting methods are approached in detail. Examples of microtomographic studies are overviewed to present an outline of biological applications of x-ray microtomography. We also provide perspectives of biological microtomography as the convergence of sciences in x-ray optics, biology, and structural analysis.

  9. Parametric X-rays at FAST

    Energy Technology Data Exchange (ETDEWEB)

    Sen, Tanaji [Fermilab

    2016-06-01

    We discuss the generation of parametric X-rays (PXR) in the photoinjector at the new FAST facility at Fermilab. Detailed calculations of the intensity spectrum, energy and angular widths and spectral brilliance with a diamond crystal are presented. We also report on expected results with PXR generated while the beam is channeling. The low emittance electron beam makes this facility a promising source for creating brilliant X-rays.

  10. Lacquer polishing of X-ray optics

    Science.gov (United States)

    Catura, R. C.; Joki, E. G.; Roethig, D. T.; Brookover, W. J.

    1987-01-01

    Techniques for polishing figured X-ray optics by a lacquer-coating process are described. This acrylic lacquer coating has been applied with an optical quality of an eighth-wave in red light and very effectively covers surface roughness with spatial wavelengths less than about 0.2 mm. Tungsten films have been deposited on the lacquer coatings to provide highly efficient X-ray reflectivity.

  11. X- rays and matter- the basic interactions

    DEFF Research Database (Denmark)

    Als-Nielsen, Jens

    2008-01-01

    In this introductory article we attempt to provide the theoretical basis for developing the interaction between X-rays and matter, so that one can unravel properties of matter by interpretation of X-ray experiments on samples. We emphasize that we are dealing with the basics, which means that we ...... this article: J. Als-Nielsen, C. R. Physique 9 (2008). Udgivelsesdato: 18 April...

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

    CERN Document Server

    Früngel, Frank B A

    1965-01-01

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

  13. X-Ray Emission from Compact Sources

    Energy Technology Data Exchange (ETDEWEB)

    Cominsky, L

    2004-03-23

    This paper presents a review of the physical parameters of neutron stars and black holes that have been derived from X-ray observations. I then explain how these physical parameters can be used to learn about the extreme conditions occurring in regions of strong gravity, and present some recent evidence for relativistic effects seen in these systems. A glossary of commonly used terms and a short tutorial on the names of X-ray sources are also included.

  14. Spectroscopy in X-ray astronomy

    Science.gov (United States)

    Andresen, R.

    1981-01-01

    Detailed features in cosmic X-ray sources and their associated temporal variation over a wide energy range were studied. Excess emission and absorption at approximately 6 to 7 kiloelectron volts in the spectra of supernova remnants, binary X-ray sources, and clusters of galaxies were observed. A gas scintillation proportional counter (GSPC) will be used as the detector system. In the gas scintillator the principal limitation is due to the statistics of the initial ionization process only.

  15. X-ray induced optical reflectivity

    OpenAIRE

    2012-01-01

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

  16. Globular cluster x-ray sources.

    Science.gov (United States)

    Pooley, David

    2010-04-20

    Globular clusters and x-ray astronomy have a long and fruitful history. Uhuru and OSO-7 revealed highly luminous (> 10(36) ergs(-1)) x-ray sources in globular clusters, and Einstein and ROSAT revealed a larger population of low-luminosity (luminosity sources were low-mass x-ray binaries in outburst and that they were orders of magnitude more abundant per unit mass in globular clusters than in the rest of the galaxy. However, the low-luminosity sources proved difficult to classify. Many ideas were put forth--low-mass x-ray binaries in quiescence (qLMXBs), cataclysmic variables (CVs), active main-sequence binaries (ABs), and millisecond pulsars (MSPs)--but secure identifications were scarce. In ROSAT observations of 55 clusters, about 25 low-luminosity sources were found. Chandra has now observed over 80 Galactic globular clusters, and these observations have revealed over 1,500 x-ray sources. The superb angular resolution has allowed for many counterpart identifications, providing clues to the nature of this population. It is a heterogeneous mix of qLMXBs, CVs, ABs, and MSPs, and it has been shown that the qLMXBs and CVs are both, in part, overabundant like the luminous LMXBs. The number of x-ray sources in a cluster correlates very well with its encounter frequency. This points to dynamical formation scenarios for the x-ray sources and shows them to be excellent tracers of the complicated internal dynamics. The relation between the encounter frequency and the number of x-ray sources has been used to suggest that we have misunderstood the dynamical states of globular clusters.

  17. Globular cluster x-ray sources

    Science.gov (United States)

    Pooley, David

    2010-01-01

    Globular clusters and x-ray astronomy have a long and fruitful history. Uhuru and OSO-7 revealed highly luminous (> 1036 ergs-1) x-ray sources in globular clusters, and Einstein and ROSAT revealed a larger population of low-luminosity (luminosity sources were low-mass x-ray binaries in outburst and that they were orders of magnitude more abundant per unit mass in globular clusters than in the rest of the galaxy. However, the low-luminosity sources proved difficult to classify. Many ideas were put forth—low-mass x-ray binaries in quiescence (qLMXBs), cataclysmic variables (CVs), active main-sequence binaries (ABs), and millisecond pulsars (MSPs)—but secure identifications were scarce. In ROSAT observations of 55 clusters, about 25 low-luminosity sources were found. Chandra has now observed over 80 Galactic globular clusters, and these observations have revealed over 1,500 x-ray sources. The superb angular resolution has allowed for many counterpart identifications, providing clues to the nature of this population. It is a heterogeneous mix of qLMXBs, CVs, ABs, and MSPs, and it has been shown that the qLMXBs and CVs are both, in part, overabundant like the luminous LMXBs. The number of x-ray sources in a cluster correlates very well with its encounter frequency. This points to dynamical formation scenarios for the x-ray sources and shows them to be excellent tracers of the complicated internal dynamics. The relation between the encounter frequency and the number of x-ray sources has been used to suggest that we have misunderstood the dynamical states of globular clusters. PMID:20404204

  18. Cooling Load Estimation in the Building Based On Heat Sources

    Science.gov (United States)

    Chairani; Sulistyo, S.; Widyawan

    2017-05-01

    Heating, ventilation and air conditioning (HVAC) is the largest source of energy consumption. In this research, we discuss cooling load in the room by considering the different heat source and the number of occupancy. Energy cooling load is affected by external and internal heat sources. External cooling load in this discussion include convection outdoor/exterior using the DOE-2 algorithm, calculation of heat using Thermal Analysis Research Program (TARP), and Conduction Transfer Function (CTF). The internal cooling load is calculated based on the activity of the occupants in the office, a number of occupants, heat gain from lighting, and heat gain from electrics equipment. Weather data used is Surakarta weather and design day used is Jakarta design day. We use the ASHRAE standard for building materials and the metabolic of occupants while on the activity. The results show that the number of occupancies have an influence of cooling load. A large number of occupancy will cause the cooling load is great as well.

  19. X-ray Emission of Hollow Atoms

    Institute of Scientific and Technical Information of China (English)

    ZhaoYongtao; XiaoGuoqing; ZhangXiaoan; YangZhihu; ChenXimeng; ZhangYanping

    2003-01-01

    We have systematically investigated the X-rays emission of hollow atoms (HA) which formed in the interaction of highly charged ions with a variety of solid surfaces at the atomic physics experimental setup of IMP. The X-ray spectra were measured by Si(Li) detectors with effective energy ranging from 1 keV to 60 keV. The results show that, the X-ray emission from the formed HA is closely correlated with the charge state of the projectile ions, and weakly correlated with the velocity of the projectile ions. For example, it was found that when Ar18+ ions interact with Be-target, the yield of K X-ray with character energy of 3.0 keV is 7.2×10-3 per ion, which is two times and 5 order of magnitude higher than those in the interactions of Ar17+ and Ar16+ ions respectively. When Ar15+ ions interact with the same targets, the Argon K X-ray would be too feeble to be detected. The X-ray yield with single ion in this experiment can be represented by the following equation,

  20. Coherence in X-ray physics.

    Science.gov (United States)

    Lengeler, B

    2001-06-01

    Highly brilliant synchrotron radiation sources have opened up the possibility of using coherent X-rays in spectroscopy and imaging. Coherent X-rays are characterized by a large lateral coherence length. Speckle spectroscopy is extended to hard X-rays, improving the resolution to the nm range. It has become possible to image opaque objects in phase contrast with a sensitivity far superior to imaging in absorption contrast. All the currently available X-ray sources are chaotic sources. Their characterization in terms of coherence functions of the first and second order is introduced. The concept of coherence volume, defined in quantum optics terms, is generalized for scattering experiments. When the illuminated sample volume is smaller than the coherence volume, the individuality of the defect arrangement in a sample shows up as speckle in the scattered intensity. Otherwise, a configurational average washes out the speckle and only diffuse scattering and possibly Bragg reflections will survive. The loss of interference due to the finite detection time, to the finite detector pixel size and to uncontrolled degrees of freedom in the sample is discussed at length. A comparison between X-ray scattering, neutron scattering and mesoscopic electron transport is given. A few examples illustrate the possibilities of coherent X-rays for imaging and intensity correlation spectroscopy.