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1

Biological Imaging by Soft X-Ray Diffraction Microscopy  

NLE Websites -- All DOE Office Websites (Extended Search)

Biological Imaging by Soft X-Ray Diffraction Microscopy Print Electron and x-ray microscopes are a valuable tool for both the life and materials sciences, but they are limited in...

2

Biological Imaging by Soft X-Ray Diffraction Microscopy  

NLE Websites -- All DOE Office Websites (Extended Search)

Biological Imaging by Soft X-Ray Diffraction Microscopy Print Biological Imaging by Soft X-Ray Diffraction Microscopy Print Electron and x-ray microscopes are a valuable tool for both the life and materials sciences, but they are limited in their ability to image with nanometer-scale resolution in three dimensions nonperiodic objects that are several microns in size. To fill this gap, the technique of coherent x-ray diffraction imaging now under development takes advantage of the penetrating power of x rays while simultaneously removing the limitations imposed by lens-based optical systems. Researchers from Stony Brook University, in collaboration with scientists at the ALS and Cornell University, have taken a large step in this direction by using a lensless x-ray diffraction microscope to image a freeze-dried yeast cell to better than 30-nm resolution. Images were made at several angular orientations of the cell.

3

Biological Imaging by Soft X-Ray Diffraction Microscopy  

NLE Websites -- All DOE Office Websites (Extended Search)

Biological Imaging by Soft X-Ray Diffraction Microscopy Print Biological Imaging by Soft X-Ray Diffraction Microscopy Print Electron and x-ray microscopes are a valuable tool for both the life and materials sciences, but they are limited in their ability to image with nanometer-scale resolution in three dimensions nonperiodic objects that are several microns in size. To fill this gap, the technique of coherent x-ray diffraction imaging now under development takes advantage of the penetrating power of x rays while simultaneously removing the limitations imposed by lens-based optical systems. Researchers from Stony Brook University, in collaboration with scientists at the ALS and Cornell University, have taken a large step in this direction by using a lensless x-ray diffraction microscope to image a freeze-dried yeast cell to better than 30-nm resolution. Images were made at several angular orientations of the cell.

4

Biological Imaging by Soft X-Ray Diffraction Microscopy  

NLE Websites -- All DOE Office Websites (Extended Search)

Biological Imaging by Soft X-Ray Diffraction Microscopy Print Biological Imaging by Soft X-Ray Diffraction Microscopy Print Electron and x-ray microscopes are a valuable tool for both the life and materials sciences, but they are limited in their ability to image with nanometer-scale resolution in three dimensions nonperiodic objects that are several microns in size. To fill this gap, the technique of coherent x-ray diffraction imaging now under development takes advantage of the penetrating power of x rays while simultaneously removing the limitations imposed by lens-based optical systems. Researchers from Stony Brook University, in collaboration with scientists at the ALS and Cornell University, have taken a large step in this direction by using a lensless x-ray diffraction microscope to image a freeze-dried yeast cell to better than 30-nm resolution. Images were made at several angular orientations of the cell.

5

Biological Imaging by Soft X-Ray Diffraction Microscopy  

NLE Websites -- All DOE Office Websites (Extended Search)

Biological Imaging by Soft X-Ray Diffraction Microscopy Print Biological Imaging by Soft X-Ray Diffraction Microscopy Print Electron and x-ray microscopes are a valuable tool for both the life and materials sciences, but they are limited in their ability to image with nanometer-scale resolution in three dimensions nonperiodic objects that are several microns in size. To fill this gap, the technique of coherent x-ray diffraction imaging now under development takes advantage of the penetrating power of x rays while simultaneously removing the limitations imposed by lens-based optical systems. Researchers from Stony Brook University, in collaboration with scientists at the ALS and Cornell University, have taken a large step in this direction by using a lensless x-ray diffraction microscope to image a freeze-dried yeast cell to better than 30-nm resolution. Images were made at several angular orientations of the cell.

6

Biological Imaging by Soft X-Ray Diffraction Microscopy  

NLE Websites -- All DOE Office Websites (Extended Search)

Biological Imaging by Soft X-Ray Biological Imaging by Soft X-Ray Diffraction Microscopy Biological Imaging by Soft X-Ray Diffraction Microscopy Print Wednesday, 30 November 2005 00:00 Electron and x-ray microscopes are a valuable tool for both the life and materials sciences, but they are limited in their ability to image with nanometer-scale resolution in three dimensions nonperiodic objects that are several microns in size. To fill this gap, the technique of coherent x-ray diffraction imaging now under development takes advantage of the penetrating power of x rays while simultaneously removing the limitations imposed by lens-based optical systems. Researchers from Stony Brook University, in collaboration with scientists at the ALS and Cornell University, have taken a large step in this direction by using a lensless x-ray diffraction microscope to image a freeze-dried yeast cell to better than 30-nm resolution. Images were made at several angular orientations of the cell.

7

Femtosecond diffractive imaging with a soft-X-ray free-electron...  

NLE Websites -- All DOE Office Websites (Extended Search)

diffractive imaging with a soft-X-ray free-electron laser We have demonstrated flash diffractive imaging of nanostructures using pulses from the first soft-X-ray free-electron...

8

Three-dimensional imaging of dislocations by X-ray diffraction laminography  

Science Conference Proceedings (OSTI)

Synchrotron radiation laminography with X-ray diffraction contrast enables three-dimensional imaging of dislocations in monocrystalline wafers. We outline the principle of the technique, the required experimental conditions, and the reconstruction procedure. The feasibility and the potential of the method are demonstrated by three-dimensional imaging of dislocation loops in an indent-damaged and annealed silicon wafer.

Haenschke, D. [Karlsruhe Institute of Technology (KIT), Laboratory for Applications of Synchrotron Radiation (LAS), 76128 Karlsruhe (Germany); Helfen, L. [Karlsruhe Institute of Technology (KIT), Institute for Photon Science and Synchrotron Radiation (IPS/ANKA), 76344 Eggenstein (Germany); European Synchrotron Radiation Facility (ESRF), BP220, 38043 Grenoble (France); Altapova, V. [Karlsruhe Institute of Technology (KIT), Laboratory for Applications of Synchrotron Radiation (LAS), 76128 Karlsruhe (Germany); National Research Tomsk Polytechnic University, 634050 Tomsk (Russian Federation); Danilewsky, A. [University Freiburg, Kristallographie, Institut fuer Geowissenschaften, 79104 Freiburg (Germany); Baumbach, T. [Karlsruhe Institute of Technology (KIT), Laboratory for Applications of Synchrotron Radiation (LAS), 76128 Karlsruhe (Germany); Karlsruhe Institute of Technology (KIT), Institute for Photon Science and Synchrotron Radiation (IPS/ANKA), 76344 Eggenstein (Germany)

2012-12-10T23:59:59.000Z

9

A framework for 3-D coherent diffraction imaging by focused beam x-ray Bragg ptychography.  

Science Conference Proceedings (OSTI)

We present the framework for convergent beam Bragg ptychography, and, using simulations, we demonstrate that nanocrystals can be ptychographically reconstructed from highly convergent x-ray Bragg diffraction. The ptychographic iterative engine is extended to three dimensions and shown to successfully reconstruct a simulated nanocrystal using overlapping raster scans with a defocused curved beam, the diameter of which matches the crystal size. This object reconstruction strategy can serve as the basis for coherent diffraction imaging experiments at coherent scanning nanoprobe x-ray sources.

Hruszkewycz, S. O.; Holt, M. V.; Tripathi, A.; Maser, J.; Fuoss, P. H. (Center for Nanoscale Materials); ( MSD); (Univ. of California at San Diego)

2011-06-15T23:59:59.000Z

10

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

DOE Patents (OSTI)

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

Smither, Robert K. (Hinsdale, IL)

2011-05-17T23:59:59.000Z

11

Coherent hard x-ray diffractive imaging of nonisolated objects confined by an aperture  

Science Conference Proceedings (OSTI)

Coherent hard x-ray imaging of nonisolated weak phase objects is demonstrated by confining x-ray beam in a region of a few micrometers in cross section using a micrometer-sized aperture. Two major obstacles in the hard x-ray coherent diffraction imaging, isolating samples and obtaining central speckles, are addressed by using the aperture. The usefulness of the proposed method is illustrated by reconstructing the exit wave field of a nanoscale trench structure fabricated on silicon which serves as a weak phase object. The quantitative phase information of the exit wave field was used to reconstruct the depth profile of the trench structure. The scanning capability of this method was also briefly discussed.

Kim, Sunam; Kim, Chan; Lee, Suyong; Marathe, Shashidhara; Noh, D. Y.; Kang, H. C.; Kim, S. S.; Sandy, A.; Narayanan, S. [Department of Materials Science and Engineering and Nanobio Materials and Electronics, Graduate Program of Photonics and Applied Physics, Gwangju Institute of Science and Technology, Gwangju 500-712 (Korea, Republic of); Department of Advanced Materials Engineering and BK21 Education Center of Mould Technology for Advanced Materials and Parts, Chosun University, Gwangju 501-759 (Korea, Republic of); Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439 (United States)

2010-04-15T23:59:59.000Z

12

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

DOE Patents (OSTI)

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

Smither, Robert K. (Hinsdale, IL)

2008-12-23T23:59:59.000Z

13

Infrared Imaging of Temperature Distribution in a High Temperature X-Ray Diffraction Furnace  

Science Conference Proceedings (OSTI)

High Temperature X-ray Diffraction (HTXRD) is a very powerful tool for studies of reaction kinetics, phase transformations, and lattice thermal expansion of advanced materials. Accurate temperature measurement is a critical part of the technique. Traditionally, thermocouples, thermistors, and optical pyrometers have been used for temperature control and measurement and temperature could only be measured at a single point. Infrared imaging was utilized in this study to characterize the thermal gradients resulting from various sample and furnace configurations in a commercial strip heater furnace. Furnace configurations include a metallic strip heater, with and without a secondary surround heater, or a surround heater alone. Sample configurations include low and high thermal conductivity powders and solids. The IR imaging results have been used to calibrate sample temperatures in the HTXRD furnace.

Payzant, E.A.; Wang, H.

1999-04-05T23:59:59.000Z

14

X-ray Imaging Workshop  

NLE Websites -- All DOE Office Websites (Extended Search)

Imaging and Spectro-microscopy: Imaging and Spectro-microscopy: the Present and the Future Stanford Synchrotron Radiation Laboratory October 8-9, 2002 Organizers: John Miao & Keith Hodgson A workshop on "X-ray Imaging and Spectro-microscopy: the Present and the Future" was held on October 8-9, 2002. This workshop, organized by John Miao (SSRL) and Keith Hodgson (SSRL) provided a forum to discuss the scientific applications of a variety of imaging and spectro-microscopic techniques, including photoemission electron microscopy (PEEM), angle resolved photoemission spectroscopy (ARPES), coherent diffraction imaging, x-ray microscopy, micro-tomography, holographic imaging, and x-ray micro-probe. Twelve invited speakers discussed the important scientific applications of these techniques, and also predicted the future scientific directions with the advance of instrumentation and x-ray sources. The workshop was well attended with over fifty registered attendees.

15

Bragg diffraction using a 100ps 17.5 keV x-ray backlighter and the Bragg Diffraction Imager  

Science Conference Proceedings (OSTI)

A new diagnostic for measuring Bragg diffraction from a laser-driven crystal using a 100ps 17.5 kV x-ray backlighter source is designed and tested successfully at the Omega EP laser facility on static Mo and Ta single crystal samples using a Mo Ka backlighter. The Bragg Diffraction Imager (BDI) consists of a heavily shielded enclosure and a precisely positioned beam block, attached to the main enclosure by an Aluminum arm. Image plate is used as the x-ray detector. The diffraction lines from Mo and Ta planes are clearly detected with a high signal-to-noise using the 17.5 keV and 19.6 keV characteristic lines generated by a petawatt-driven Mo foil. This technique will be applied to shock and ramp-loaded single crystals on the Omega EP laser. Pulsed x-ray diffraction of shock- and ramp-compressed materials is an exciting new technique that can give insight into the dynamic behavior of materials at ultra-high pressure not achievable by any other means to date. X-ray diffraction can be used to determine not only the phase and compression of the lattice at high pressure, but by probing the lattice compression on a timescale equal to the 3D relaxation time of the material, information about dislocation mechanics, including dislocation multiplication rate and velocity, can also be derived. Both Bragg, or reflection, and Laue, or transmission, diffraction have been developed for shock-loaded low-Z crystalline structures such as Cu, Fe, and Si using nano-second scale low-energy implosion and He-{alpha} x-ray backlighters. However, higher-Z materials require higher x-ray probe energies to penetrate the samples, such as in Laue, or probe deep enough into the target, as in the case of Bragg diffraction. Petawatt laser-generated K{alpha} x-ray backlighters have been developed for use in high-energy radiography of dense targets and other HED applications requiring picosecond-scale burst of hard x-rays. While short pulse lasers are very efficient at producing high-energy x-rays, the characteristic x-rays produced in these thin foil targets are superimposed on a broad bremsstrahlung background and can easily saturate a detector if careful diagnostic shielding and experimental geometry are not implemented. A new diagnostic has been designed to measure Bragg diffraction from laser-driven crystal targets using characteristic x-rays from a short-pulse laser backlighter on the Omega EP laser. The Bragg Diffraction Imager, or BDI, is a TIM-mounted instrument consisting of a heavily shielded enclosure made from 3/8-inch thick Heavymet (W-Fe-Ni alloy) and a precisely positioned beam bock, attached to the main enclosure by an Aluminum arm. The beam block is made of 1-inch thick, Al-coated Heavymet and serves to block the x-rays directly from the petawatt backlight, while allowing the diffraction x-rays from the crystal to pass to the enclosure. A schematic of the BDI is shown in Fig. 1a. Image plates are used as the x-ray detector and are loaded through the top of the diagnostic in an Aluminum, light-tight cartridge. The front of the enclosure can be fitted with various filters to maximize the diffraction signal-to-noise.

Maddox, B R; Park, H; Hawreliak, J; Comley, A; Elsholz, A; Van Maren, R; Remington, B A; Wark, J

2010-05-13T23:59:59.000Z

16

Soft X-Ray Microscopy at HZB: Zone Plate Development and Imaging Using the Third Order of Diffraction  

Science Conference Proceedings (OSTI)

The Helmholtz-Zentrum Berlin (HZB) operates a transmission x-ray microscope (TXM) in the soft x-ray photon energy range with an energy resolution up to E/{Delta}E = 10{sup 4}. An approach to achieve ultrahigh spatial resolution with conventional, standard zone plate optics is to employ higher orders of diffraction of the zone plate objective. In this paper, we demonstrate that 11-nm lines and spaces of a multilayer test structure are clearly resolved by the x-ray microscope using the third order of diffraction of a zone plate objective with 20-nm outermost zone width. The disadvantage of high-order imaging is an about one order of magnitude lower diffraction efficiency of the used zone plates employed in the third order compared to the first order of diffraction. In addition, the measured background signal in the TXM images is no longer negligible. Therefore, we worked on the fabrication of zone plates with sub-20-nm outermost zone width to increase the spatial resolution in the first order of diffraction. A new high-resolution 100-keV e-beam lithography system from VISTEC, which was recently installed at the Helmholtz-Zentrum Berlin, makes these developments possible. Initial results on zone plates with an outermost zone width down to 15 nm exposed with the new e-beam system are presented. Furthermore, the contrast transfer function of the transmission x-ray microscope operating in partial coherence mode is measured by using the first and third diffraction order of the zone plate objective.

Rehbein, S.; Guttmann, P.; Werner, S.; Schneider, G. [Helmholtz-Zentrum Berlin fuer Materialien und Energie GmbH, Wilhelm-Conrad-Roentgen-Campus, BESSY II, Albert-Einstein-Str. 15, 12489 Berlin (Germany)

2011-09-09T23:59:59.000Z

17

X-Ray Diffraction Microscopy of Magnetic Structures  

NLE Websites -- All DOE Office Websites (Extended Search)

X-Ray Diffraction Microscopy of Magnetic Structures Print X-Ray Diffraction Microscopy of Magnetic Structures Print science brief icon Scientists working at ALS Beamline 12.0.2.2 have demonstrated a new x-ray technique for producing short-exposure nanoscale images of the magnetic structure of materials. The new method combines aspects of coherent x-ray diffraction, which can determine 3-D charge distributions, and resonant magnetic scattering, which is sensitive to magnetic structures. Physicists have used coherent x-ray diffraction to measure the electron density of complicated molecules. The formula used to make these calculations contains terms that relate to the electron spin of magnetic atoms, but these terms are traditionally ignored since coherent x-ray diffraction has not been used to retrieve magnetic information. Using the full formula allows for the determination of not only the electron density, but also the magnetic spin distribution and its orientation.

18

X-Ray Diffraction Microscopy of Magnetic Structures  

NLE Websites -- All DOE Office Websites (Extended Search)

X-Ray Diffraction Microscopy of Magnetic Structures Print X-Ray Diffraction Microscopy of Magnetic Structures Print science brief icon Scientists working at ALS Beamline 12.0.2.2 have demonstrated a new x-ray technique for producing short-exposure nanoscale images of the magnetic structure of materials. The new method combines aspects of coherent x-ray diffraction, which can determine 3-D charge distributions, and resonant magnetic scattering, which is sensitive to magnetic structures. Physicists have used coherent x-ray diffraction to measure the electron density of complicated molecules. The formula used to make these calculations contains terms that relate to the electron spin of magnetic atoms, but these terms are traditionally ignored since coherent x-ray diffraction has not been used to retrieve magnetic information. Using the full formula allows for the determination of not only the electron density, but also the magnetic spin distribution and its orientation.

19

X-Ray Diffraction Microscopy of Magnetic Structures  

NLE Websites -- All DOE Office Websites (Extended Search)

X-Ray Diffraction Microscopy of Magnetic Structures Print X-Ray Diffraction Microscopy of Magnetic Structures Print science brief icon Scientists working at ALS Beamline 12.0.2.2 have demonstrated a new x-ray technique for producing short-exposure nanoscale images of the magnetic structure of materials. The new method combines aspects of coherent x-ray diffraction, which can determine 3-D charge distributions, and resonant magnetic scattering, which is sensitive to magnetic structures. Physicists have used coherent x-ray diffraction to measure the electron density of complicated molecules. The formula used to make these calculations contains terms that relate to the electron spin of magnetic atoms, but these terms are traditionally ignored since coherent x-ray diffraction has not been used to retrieve magnetic information. Using the full formula allows for the determination of not only the electron density, but also the magnetic spin distribution and its orientation.

20

Design and imaging performance of achromatic diffractive/refractive X-ray and Gamma-ray Fresnel lenses  

E-Print Network (OSTI)

Achromatic combinations of a diffractive Phase Fresnel Lens and a refractive correcting element have been proposed for X-ray and gamma-ray astronomy and for microlithography, but considerations of absorption often dictate that the refractive component be given a stepped profile, resulting in a double Fresnel lens. The imaging performance of corrected Fresnel lenses, with and without `stepping' is investigated and the trade-off between resolution and useful bandwidth in different circumstances is discussed. Provided the focal ratio is large, correction lenses made of low atomic number materials can be used with X-rays in the range approximately 10--100 keV without stepping. The use of stepping extends the possibility of correction to higher aperture systems, to energies as low as a few kilo electron volts and to gamma-rays of $\\sim$ mega electron volt energy.

Gerald K. Skinner

2004-07-21T23:59:59.000Z

Note: This page contains sample records for the topic "x-ray diffraction imaging" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

Bragg diffraction using a 100 ps 17.5 keV x-ray backlighter and the Bragg diffraction imager  

Science Conference Proceedings (OSTI)

A new diagnostic for measuring Bragg diffraction of petawatt-generated high-energy x rays off a laser-compressed crystal was designed and tested successfully at the Omega EP laser facility on static Mo and Ta (111) oriented single crystal samples using a 17.5 keV Mo K{alpha} backlighter. The Bragg diffraction imager consists of a heavily shielded enclosure and a precisely positioned beam block attached to the enclosure by an aluminum arm. Fuji image plates are used as the x-ray detectors. The diffraction from Mo and Ta (222) crystal planes was clearly detected with a high signal-to-noise. This technique will be applied to shock- and quasi-isentropically loaded single crystals on the Omega EP laser.

Maddox, B. R.; Park, H.-S.; Hawreliak, J.; Elsholz, A.; Van Maren, R.; Remington, B. A. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Comley, A. [AWE, Reading, Berkshire RG7 4PR (United Kingdom); Wark, J. S. [Department of Physics, Clarendon Laboratory, University of Oxford, Parks Road, Oxford, OX1 3PU (United Kingdom)

2010-10-15T23:59:59.000Z

22

Orientation Determination in Single Particle X-ray Coherent Diffraction Imaging Experiments  

E-Print Network (OSTI)

Single particle diffraction imaging experiments at free-electron lasers (FEL) have a great potential for structure determination of reproducible biological specimens that can not be crystallized. One of the challenges in processing the data from such an experiment is to determine correct orientation of each diffraction pattern from samples randomly injected in the FEL beam. We propose an algorithm (see also O. Yefanov et al., Photon Science - HASYLAB Annual Report 2010) that can solve this problem and can be applied to samples from tens of nanometers to microns in size, measured with sub-nanometer resolution in the presence of noise. This is achieved by the simultaneous analysis of a large number of diffraction patterns corresponding to different orientations of the particles. The algorithms efficiency is demonstrated for two biological samples, an artificial protein structure without any symmetry and a virus with icosahedral symmetry. Both structures are few tens of nanometers in size and consist of more than 100 000 non-hydrogen atoms. More than 10 000 diffraction patterns with Poisson noise were simulated and analyzed for each structure. Our simulations indicate the possibility to achieve resolution of about 3.3 {\\AA} at 3 {\\AA} wavelength and incoming flux of 10^{12} photons per pulse focused to 100\\times 100 nm^2.

O. M. Yefanov; I. A. Vartanyants

2013-02-22T23:59:59.000Z

23

Gas gun shock experiments with single-pulse x-ray phase contrast imaging and diffraction at the Advanced Photon Source  

Science Conference Proceedings (OSTI)

The highly transient nature of shock loading and pronounced microstructure effects on dynamic materials response call for in situ, temporally and spatially resolved, x-ray-based diagnostics. Third-generation synchrotron x-ray sources are advantageous for x-ray phase contrast imaging (PCI) and diffraction under dynamic loading, due to their high photon fluxes, high coherency, and high pulse repetition rates. The feasibility of bulk-scale gas gun shock experiments with dynamic x-ray PCI and diffraction measurements was investigated at the beamline 32ID-B of the Advanced Photon Source. The x-ray beam characteristics, experimental setup, x-ray diagnostics, and static and dynamic test results are described. We demonstrate ultrafast, multiframe, single-pulse PCI measurements with unprecedented temporal (dynamic Laue diffraction. The results not only substantiate the potential of synchrotron-based experiments for addressing a variety of shock physics problems, but also allow us to identify the technical challenges related to image detection, x-ray source, and dynamic loading.

Luo, S. N.; Jensen, B. J.; Hooks, D. E.; Ramos, K. J.; Yeager, J. D.; Kwiatkowski, K.; Shimada, T. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Fezzaa, K. [Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439 (United States)

2012-07-15T23:59:59.000Z

24

Lensless X-Ray Imaging in Reflection  

NLE Websites -- All DOE Office Websites (Extended Search)

Lensless X-Ray Imaging in Lensless X-Ray Imaging in Reflection Lensless X-Ray Imaging in Reflection Print Wednesday, 26 October 2011 00:00 The advent of x-ray free-electron laser (XFEL) light sources has led to an outburst of research activities in the field of lensless imaging. XFELs combine the advantages of sychrotron light sources (high brightness and x-ray wavelengths relevant to atomic and molecular phenomena) with the advantages of visible-light lasers (highly coherent beams). All of these characteristics are important for coherent x-ray diffraction imaging-lensless imaging techniques that are proving to be integral to single-shot, high-resolution imaging of both complex materials and biological samples. Existing techniques are typically designed for transmission geometry, however, and use isolated objects, requiring special sample fabrication and restricting the type of samples under investigation. Recently, researchers from the ALS and the University of Oregon have shown at ALS Beamline 12.0.2 that it is possible to form x-ray holograms in reflection geometry by using the light scattered from a sample, opening the door to lensless imaging of a wealth of new material samples.

25

Femtosecond diffractive imaging with a soft-X-ray free-electron laser  

DOE Data Explorer (OSTI)

The diffraction pattern of this entry corresponds to the one shown in **figure 2a** of the corresponding citation.

Chapman, H. N.

26

Lensless X-Ray Imaging in Reflection  

NLE Websites -- All DOE Office Websites (Extended Search)

Lensless X-Ray Imaging in Reflection Print Lensless X-Ray Imaging in Reflection Print The advent of x-ray free-electron laser (XFEL) light sources has led to an outburst of research activities in the field of lensless imaging. XFELs combine the advantages of sychrotron light sources (high brightness and x-ray wavelengths relevant to atomic and molecular phenomena) with the advantages of visible-light lasers (highly coherent beams). All of these characteristics are important for coherent x-ray diffraction imaging-lensless imaging techniques that are proving to be integral to single-shot, high-resolution imaging of both complex materials and biological samples. Existing techniques are typically designed for transmission geometry, however, and use isolated objects, requiring special sample fabrication and restricting the type of samples under investigation. Recently, researchers from the ALS and the University of Oregon have shown at ALS Beamline 12.0.2 that it is possible to form x-ray holograms in reflection geometry by using the light scattered from a sample, opening the door to lensless imaging of a wealth of new material samples.

27

Lensless X-Ray Imaging in Reflection  

NLE Websites -- All DOE Office Websites (Extended Search)

Lensless X-Ray Imaging in Reflection Print Lensless X-Ray Imaging in Reflection Print The advent of x-ray free-electron laser (XFEL) light sources has led to an outburst of research activities in the field of lensless imaging. XFELs combine the advantages of sychrotron light sources (high brightness and x-ray wavelengths relevant to atomic and molecular phenomena) with the advantages of visible-light lasers (highly coherent beams). All of these characteristics are important for coherent x-ray diffraction imaging-lensless imaging techniques that are proving to be integral to single-shot, high-resolution imaging of both complex materials and biological samples. Existing techniques are typically designed for transmission geometry, however, and use isolated objects, requiring special sample fabrication and restricting the type of samples under investigation. Recently, researchers from the ALS and the University of Oregon have shown at ALS Beamline 12.0.2 that it is possible to form x-ray holograms in reflection geometry by using the light scattered from a sample, opening the door to lensless imaging of a wealth of new material samples.

28

Lensless X-Ray Imaging in Reflection  

NLE Websites -- All DOE Office Websites (Extended Search)

X-Ray Imaging in Reflection Print X-Ray Imaging in Reflection Print The advent of x-ray free-electron laser (XFEL) light sources has led to an outburst of research activities in the field of lensless imaging. XFELs combine the advantages of sychrotron light sources (high brightness and x-ray wavelengths relevant to atomic and molecular phenomena) with the advantages of visible-light lasers (highly coherent beams). All of these characteristics are important for coherent x-ray diffraction imaging-lensless imaging techniques that are proving to be integral to single-shot, high-resolution imaging of both complex materials and biological samples. Existing techniques are typically designed for transmission geometry, however, and use isolated objects, requiring special sample fabrication and restricting the type of samples under investigation. Recently, researchers from the ALS and the University of Oregon have shown at ALS Beamline 12.0.2 that it is possible to form x-ray holograms in reflection geometry by using the light scattered from a sample, opening the door to lensless imaging of a wealth of new material samples.

29

Lensless X-Ray Imaging in Reflection  

NLE Websites -- All DOE Office Websites (Extended Search)

X-Ray Imaging in Reflection Print X-Ray Imaging in Reflection Print The advent of x-ray free-electron laser (XFEL) light sources has led to an outburst of research activities in the field of lensless imaging. XFELs combine the advantages of sychrotron light sources (high brightness and x-ray wavelengths relevant to atomic and molecular phenomena) with the advantages of visible-light lasers (highly coherent beams). All of these characteristics are important for coherent x-ray diffraction imaging-lensless imaging techniques that are proving to be integral to single-shot, high-resolution imaging of both complex materials and biological samples. Existing techniques are typically designed for transmission geometry, however, and use isolated objects, requiring special sample fabrication and restricting the type of samples under investigation. Recently, researchers from the ALS and the University of Oregon have shown at ALS Beamline 12.0.2 that it is possible to form x-ray holograms in reflection geometry by using the light scattered from a sample, opening the door to lensless imaging of a wealth of new material samples.

30

Coherent Diffraction Imaging of Materials by Using an X-ray Free ...  

Science Conference Proceedings (OSTI)

Study of Charge-Ordering in Manganites via Serial Femtosecond Crystallography · XFEL Materials Imaging at the LCLS CXI Endstation ...

31

Optical systems for synchrotron radiation: lecture 4. Soft x-ray imaging systems  

Science Conference Proceedings (OSTI)

The history and present techniques of soft x-ray imaging are reviewed briefly. The physics of x-ray imaging is described, including the temporal and spatial coherence of x-ray sources. Particular technologies described are: contact x-ray microscopy, zone plate imaging, scanned image zone plate microscopy, scanned image reflection microscopy, and soft x-ray holography and diffraction. (LEW)

Howells, M.R.

1986-04-01T23:59:59.000Z

32

X-Ray Diffraction on NIF  

SciTech Connect

The National Ignition Facility (NIF) is currently a 192 beam, 1.6 MJ laser. NIF Ramp-Compression Experiments have already made the relevant exo-planet pressure range from 1 to 50 Mbar accessible. We Proposed to Study Carbon Phases by X-Ray Diffraction on NIF. Just a few years ago, ultra-high pressure phase diagrams for materials were very 'simple'. New experiments and theories point out surprising and decidedly complex behavior at the highest pressures considered. High pressures phases of aluminum are also predicted to be complex. Recent metadynamics survey of carbon proposed a dynamic pathway among multiple phases. We need to develop diagnostics and techniques to explore this new regime of highly compressed matter science. X-Ray Diffraction - Understand the phase diagram/EOS/strength/texture of materials to 10's of Mbar. Strategy and physics goals: (1) Powder diffraction; (2) Begin with diamond; (3) Continue with metals etc.; (4) Explore phase diagrams; (5) Develop liquid diffraction; and (6) Reduce background/improve resolution.

Eggert, J H; Wark, J

2012-02-15T23:59:59.000Z

33

X-Ray Diffraction Project Final Report, Fiscal Year 2006  

SciTech Connect

An x-ray diffraction diagnostic system was developed for determining real-time shock-driven lattice parameter shifts in single crystals at the gas gun at TA-IV at Sandia National Laboratories (SNL). The signal-to-noise ratio and resolution of the system were measured using imaging plates as the detector and by varying the slit width. This report includes tests of the x-ray diffraction system using a phosphor coupled to a charge-coupled device (CCD) camera by a coherent fiber-optic bundle. The system timing delay was measured with a newly installed transistor-transistor logic (TTL) bypass designed to reduce the x-ray delay time. The axial misalignment of the Bragg planes was determined with respect to the optical axis for a set of eight LiF [lithium fluoride] crystals provided by SNL to determine their suitability for gas gun experiments.

Dane V. Morgan

2006-10-01T23:59:59.000Z

34

Transient x-ray diffraction and its application to materials science and x-ray optics  

SciTech Connect

Time resolved x-ray diffraction and scattering have been applied to the measurement of a wide variety of physical phenomena from chemical reactions to shock wave physics. Interest in this method has heightened in recent years with the advent of versatile, high power, pulsed x-ray sources utilizing laser plasmas, electron beams and other methods. In this article, we will describe some of the fundamentals involved in time resolved x-ray diffraction, review some of the history of its development, and describe some recent progress in the field. In this article we will emphasize the use of laser-plasmas as the x-ray source for transient diffraction.

Hauer, A.A.; Kopp, R.; Cobble, J.; Kyrala, G.; Springer, R. [and others

1997-12-01T23:59:59.000Z

35

Definition: X-Ray Diffraction (XRD) | Open Energy Information  

Open Energy Info (EERE)

X-Ray Diffraction (XRD) X-Ray Diffraction (XRD) Jump to: navigation, search Dictionary.png X-Ray Diffraction (XRD) X-Ray Diffraction (XRD) is a laboratory-based technique commonly used for identification of crystalline materials and analysis of unit cell dimensions. One of two primary types of XRD analysis (X-ray powder diffraction and single-crystal XRD) is commonly applied to samples to obtain specific information about the crystalline material under investigation. X-ray powder diffraction is widely used in geology, environmental science, material science, and engineering to rapidly identify unknown crystalline substances (typically in less than 20 minutes). A pure, finely ground, and homogenized sample is required for determination of the bulk composition. Additional uses include detailed

36

X-Ray Diffraction (XRD) | Open Energy Information  

Open Energy Info (EERE)

X-Ray Diffraction (XRD) X-Ray Diffraction (XRD) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Technique: X-Ray Diffraction (XRD) Details Activities (0) Areas (0) Regions (0) NEPA(0) Exploration Technique Information Exploration Group: Lab Analysis Techniques Exploration Sub Group: Rock Lab Analysis Parent Exploration Technique: Rock Lab Analysis Information Provided by Technique Lithology: Rapid and unambiguous identification of unknown minerals.[1] Stratigraphic/Structural: Hydrological: Thermal: Dictionary.png X-Ray Diffraction (XRD): X-Ray Diffraction (XRD) is a laboratory-based technique commonly used for identification of crystalline materials and analysis of unit cell dimensions. One of two primary types of XRD analysis (X-ray powder diffraction and single-crystal XRD) is commonly applied to samples to

37

Portable X-Ray Diffraction (XRD) | Open Energy Information  

Open Energy Info (EERE)

Portable X-Ray Diffraction (XRD) Portable X-Ray Diffraction (XRD) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Technique: Portable X-Ray Diffraction (XRD) Details Activities (0) Areas (0) Regions (0) NEPA(0) Exploration Technique Information Exploration Group: Field Techniques Exploration Sub Group: Data Collection and Mapping Parent Exploration Technique: Data Collection and Mapping Information Provided by Technique Lithology: Rapid and unambiguous identification of unknown minerals.[1] Stratigraphic/Structural: Hydrological: Thermal: Dictionary.png Portable X-Ray Diffraction (XRD): Portable X-Ray Diffraction (XRD) is a field-based technique that can be used for identification of crystalline materials and analysis of unit cell dimensions. Portable XRD analysis is similar to X-ray powder diffraction,

38

X-Ray and Neutron Diffraction - Programmaster.org  

Science Conference Proceedings (OSTI)

Oct 20, 2010 ... Strain Determination in Nanoscale Microelectronic Materials Using X-Ray Diffraction: Conal Murray1; 1IBM T.J. Watson Research Center

39

Grain Boundary Deformation Analyzed Via X-Ray Diffraction ...  

Science Conference Proceedings (OSTI)

Modeling the Influence of the Second Phase Particle Spatial Distribution on Recrystallization of AA 7050 · Near-Field High Energy X-ray Diffraction Microscopy ...

40

X-Ray and Neutron Diffraction  

Science Conference Proceedings (OSTI)

Oct 20, 2010 ... Advanced X-Ray Scattering Techniques for Multi-Length Scale ... ?-Ti using the 3DXRD station 34-ID-E at the Advanced Photon Source, Argonne National Laboratory. ... Research at APS 34-ID-E, partly funded by BES/DOE.

Note: This page contains sample records for the topic "x-ray diffraction imaging" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

Definition: Portable X-Ray Diffraction (XRD) | Open Energy Information  

Open Energy Info (EERE)

Definition Definition Edit with form History Facebook icon Twitter icon » Definition: Portable X-Ray Diffraction (XRD) Jump to: navigation, search Dictionary.png Portable X-Ray Diffraction (XRD) Portable X-Ray Diffraction (XRD) is a field-based technique that can be used for identification of crystalline materials and analysis of unit cell dimensions. Portable XRD analysis is similar to X-ray powder diffraction, which has traditionally been used in geology, environmental science, material science, and engineering to rapidly identify unknown crystalline substances. Portable XRD analysis allows for simpler sample preparation, faster analytical times than traditional methods (less than 2 minutes), and can be performed at the sampling site in the field. A pure, finely ground

42

Quantitative Analysis of Mt. St. Helens Ash by X-Ray Diffraction and X-Ray Fluorescence Spectrometry  

Science Conference Proceedings (OSTI)

A quantitative study by x-ray diffraction, optical polarizing microscopy, and x-ray fluorescence spectrometry of fallout and ambient ash from three Mt. St. Helens eruptions has revealed a consistent picture of the mineralogical and elemental ...

Briant L. Davis; L. Ronald Johnson; Dana T. Griffen; William Revell Phillips; Robert K. Stevens; David Maughan

1981-08-01T23:59:59.000Z

43

Shaping X-rays by diffractive coded nano-optics  

Science Conference Proceedings (OSTI)

In this paper we report results obtained in the fabrication and use of novel coded diffractive nano-optics that, beyond focusing, can perform new optical functions. In particular, the intensity of light in the space beyond the optical elements can be ... Keywords: X-ray beamshaping, coded diffractive optical element, nano-optics

E. Di Fabrizio; S. Cabrini; D. Cojoc; F. Romanato; L. Businaro; M. Altissimo; B. Kaulich; T. Wilhein; J. Susini; M. De Vittorio; E. Vitale; G. Gigli; R. Cingolani

2003-06-01T23:59:59.000Z

44

Photon Sciences | Beamlines | XPD: X-ray Powder Diffraction  

NLE Websites -- All DOE Office Websites (Extended Search)

XPD: X-ray Powder Diffraction XPD: X-ray Powder Diffraction Poster | Fact Sheet | Preliminary Design Report Scientific Scope XPD is a tunable facility with the ability to collect diffraction data at high x-ray energies (40keV-80keV), offering rapid acquisition (millisecond) and high angular resolution capabilities on the same instrument. XPD addresses future scientific challenges in, for example, hydrogen storage, CO2 sequestration, advanced structural ceramics, catalysis, and materials processing. Such materials of high technological value often are complex, nanostructured and heterogeneous. The scientific grand challenge is to obtain robust and quantitative (micro)structural information, not only in the ground state at ambient conditions, but also in situ or in operando with varying temperature, pressure, magnetic/electric/stress

45

Imaging X-ray Thomson Scattering Spectrometer Design and Demonstration  

SciTech Connect

In many laboratory astrophysics experiments, intense laser irradiation creates novel material conditions with large, one-dimensional gradients in the temperature, density, and ionization state. X-ray Thomson scattering is a powerful technique for measuring these plasma parameters. However, the scattered signal has previously been measured with little or no spatial resolution, which limits the ability to diagnose inhomogeneous plasmas. We report on the development of a new imaging x-ray Thomson spectrometer (IXTS) for the Omega laser facility. The diffraction of x-rays from a toroidally-curved crystal creates high-resolution images that are spatially resolved along a one-dimensional profile while spectrally dispersing the radiation. This focusing geometry allows for high brightness while localizing noise sources and improving the linearity of the dispersion. Preliminary results are presented from a scattering experiment that used the IXTS to measure the temperature profile of a shocked carbon foam.

Gamboa, E.J. [University of Michigan; Huntington, C.M. [University of Michigan; Trantham, M.R. [University of Michigan; Keiter, P.A [University of Michigan; Drake, R.P. [University of Michigan; Montgomery, David [Los Alamos National Laboratory; Benage, John F. [Los Alamos National Laboratory; Letzring, Samuel A. [Los Alamos National Laboratory

2012-05-04T23:59:59.000Z

46

X-ray diffraction data for plutonium compounds  

Science Conference Proceedings (OSTI)

This work is a compilation of x-ray diffraction information relating to powder photographs of plutonium compounds. The information is presented in a format and style substantially as recommended by the International Centre for Diffraction Data. The Los Alamos National Laboratory has been very much involved in the study of the properties of plutonium and its compounds. During the past 45 years the Powder Diffraction File of the Laboratory has grown to more than 20,000 films. F.H. Ellinger and his coworkers have used this data to establish a large number of plutonium binary phase diagrams. A phase diagram, however, should never be regarded as really complete as new techniques of alloy preparation or x-ray and optical metallography continually discover new phases that must be incorporated in the diagram. In addition to the phase diagrams, the crystal structure of a number of plutonium intermetallic compounds have been determined at Los Alamos. Due to the importance of plutonium as a representative of the actinide series of elements, it is deemed advisable to have available information on the x-ray diffraction of plutonium and its compounds for the purpose of identification of these materials. It is hoped that the information presented here will be of value in this regard.

Roof, R.B.

1989-10-01T23:59:59.000Z

47

X-ray Diffraction Crystal Calibration and Characterization  

SciTech Connect

National Security Technologies’ X-ray Laboratory is comprised of a multi-anode Manson type source and a Henke type source that incorporates a dual goniometer and XYZ translation stage. The first goniometer is used to isolate a particular spectral band. The Manson operates up to 10 kV and the Henke up to 20 kV. The Henke rotation stages and translation stages are automated. Procedures have been developed to characterize and calibrate various NIF diagnostics and their components. The diagnostics include X-ray cameras, gated imagers, streak cameras, and other X-ray imaging systems. Components that have been analyzed include filters, filter arrays, grazing incidence mirrors, and various crystals, both flat and curved. Recent efforts on the Henke system are aimed at characterizing and calibrating imaging crystals and curved crystals used as the major component of an X-ray spectrometer. The presentation will concentrate on these results. The work has been done at energies ranging from 3 keV to 16 keV. The major goal was to evaluate the performance quality of the crystal for its intended application. For the imaging crystals we measured the laser beam reflection offset from the X-ray beam and the reflectivity curves. For the curved spectrometer crystal, which was a natural crystal, resolving power was critical. It was first necessary to find sources of crystals that had sufficiently narrow reflectivity curves. It was then necessary to determine which crystals retained their resolving power after being thinned and glued to a curved substrate.

Michael J. Haugh; Richard Stewart; Nathan Kugland

2009-06-05T23:59:59.000Z

48

X-ray Image Bank Open for Business - NERSC Center News, Feb 22, 2011  

NLE Websites -- All DOE Office Websites (Extended Search)

X-ray Image Bank Open X-ray Image Bank Open for Business X-ray Image Bank Open for Business February 22, 2011 Filipe Maia is building a data bank where scientists from around the world can deposit and share images generated by coherent x-ray light sources. A post-doctoral researcher with the National Energy Research Scientific Computing Center (NERSC), Maia hopes the Coherent X-ray Imaging Data Bank, or CXIDB (http://www.cxidb.org) can help researchers make the most of their valuable data. Scientists use light sources to shoot intense x-ray beams into molecules, such as proteins, in order to understand their shapes and structures. The resulting diffraction patterns are painstakingly reconstructed to deduce an image. "It kind of works like a microscope, but it has no lens," Maia says.

49

X-ray diffraction data for plutonium compounds  

Science Conference Proceedings (OSTI)

This work is a compilation of x-ray diffraction information relating to powder photographs of plutonium compounds. The information is presented in a format and style substantially as recommended by the International Center for Diffraction Data. Los Alamos National Laboratory has been involved in the study of the properties of plutonium and its compounds. During the past 45 years, the Powder Diffraction File of the Laboratory has grown to more than 20,000 films. F.H. Ellinger and his coworkers have used this data to establish a large number of plutonium binary phase diagrams. These phase diagrams have been published in a special report of the Laboratory, LA-3870, Constitution of Plutonium Alloys,'' authored by F.H. Ellinger, W.N. Miner, D.R. O'Boyle, and F.W. Schonfeld. A phase diagram, however, should never be regarded as really complete as new techniques of alloy preparation or x-ray and optical metallography continually discover new phases that must be incorporated in the diagram. In addition to the phase diagrams, the crystal structures of a number of plutonium intermetallic compounds have been determined at Los Alamos and published in the general literature by D.T. Cromer, A.C. Larson, and R.B. Roof over the last 35 years.

Roof, R.B.

1991-06-01T23:59:59.000Z

50

The three dimensional X-ray diffraction technique  

SciTech Connect

This introductory tutorial describes the so called 3 dimensional X-ray diffraction (3DXRD) technique, which allows bulk non-destructive structural characterizations of crystalline materials. The motivations and history behind the development of this technique are described and its potentials are sketched. Examples of the use of the technique are given and future trends and developments are suggested. The primary aim of the paper is to give 3DXRD novices an easy introduction to the technique and to describe a way from a dream to reality and new results.

Jensen, D. Juul; Poulsen, H.F. (Denmark)

2012-10-24T23:59:59.000Z

51

Anomalous X-ray Diffraction Studies for Photovoltaic Applications  

DOE Green Energy (OSTI)

Anomalous X-ray Diffraction (AXRD) has become a useful technique in characterizing bulk and nanomaterials as it provides specific information about the crystal structure of materials. In this project we present the results of AXRD applied to materials for photovoltaic applications: ZnO loaded with Ga and ZnCo{sub 2}O{sub 4} spinel. The X-ray diffraction data collected for various energies were plotted in Origin software. The peaks were fitted using different functions including Pseudo Voigt, Gaussian, and Lorentzian. This fitting provided the integrated intensity data (peaks area values), which when plotted as a function of X-ray energies determined the material structure. For the first analyzed sample, Ga was not incorporated into the ZnO crystal structure. For the ZnCo{sub 2}O{sub 4} spinel Co was found in one or both tetrahedral and octahedral sites. The use of anomalous X-ray diffraction (AXRD) provides element and site specific information for the crystal structure of a material. This technique lets us correlate the structure to the electronic properties of the materials as it allows us to probe precise locations of cations in the spinel structure. What makes it possible is that in AXRD the diffraction pattern is measured at a number of energies near an X-ray absorption edge of an element of interest. The atomic scattering strength of an element varies near its absorption edge and hence the total intensity of the diffraction peak changes by changing the X-ray energy. Thus AXRD provides element specific structural information. This method can be applied to both crystalline and liquid materials. One of the advantages of AXRD in crystallography experiments is its sensitivity to neighboring elements in the periodic tables. This method is also sensitive to specific crystallographic phases and to a specific site in a phase. The main use of AXRD in this study is for transparent conductors (TCs) analysis. TCs are considered to be important materials because of their efficiency and low risk of environmental pollution. These materials are important to solar cells as a result of their remarkable combination of optical and electrical properties, including high electrical conductivity and high optical transparency in the spectrum of visible light. TCs provide a transparent window, which allows sunlight to pass through while also allowing electricity to conduct out of the cell. Spinel materials have the chemical form AB{sub 2}O{sub 4}, and are made of a face-centered cubic (FCC) lattice of oxygen anions and cations in specific interstitial sites. A normal spinel has all A cations on tetrahedral sites and B cations on octahedral sites. In contrast; an inverse spinel has the A and half of the B cations on octahedral sites and the other half of the B cations on tetrahedral sites; a mixed spinel lies between. In the spinel structure, 8 of 64 possible tetrahedral sites and 16 of 32 possible octahedral sites are filled. Normal spinels have particularly high conduction as the linear octahedral chains of B cations likely serve as conduction paths. In this paper we present how the data obtained with AXRD is used to analyze TCs properties as they apply to photovoltaic applications. One of the materials used for this analysis is zinc oxide. It has been loaded with 5% and 10% of Ga, which has an absorption edge of 10367 eV. The peak (100) was measured for the zinc oxide loaded with 10% Ga. In the case of 5% Ga, we measured peaks (100) and (101). With the information provided by the AXRD we can identify if Ga is being incorporated in the ZnO crystal structure. The analysis of 311 plane in the ZnCo{sub 2}O{sub 4} spinel shows if Co is in tetrahedral or octahedral site.

Not Available

2011-06-22T23:59:59.000Z

52

X-ray Microscopy and Imaging: 2-BM  

NLE Websites -- All DOE Office Websites (Extended Search)

BM BM Introduction The 2-BM beamline offers measurement capabilities for x-ray microtomography, x-ray topography and x-ray microdiffraction. X-ray microtomography and x-ray diffraction instruments are installed on separate optical tables for independent operation with fast switch over time. Optically-coupled high-resolution CCD system is used for microtomography and topography with up to 1 micron spatial resolution. X-ray microdiffraction setup consists of KB microfocussing mirrors (~3 micron minimum spot), four-circle Huber diffractometer, high-precision translation sample stage, two orthogonally-mounted video cameras for viewing sample, fluorescence detector (Si-drift diode) and diffraction detector (a scintillation detector or a CCD). Three different levels of monochromaticity are available. Conventional monochromatic x-rays from a double-bounced Si (111) crystal monochromator (DCM, D E/E=1E-4), wide band-pass monochromatic x-rays from a double multilayer monochromator (DMM, D E/E=1~4E-2) and pink beam. The available x-ray range is from 5 keV to 30 keV. The lower limit is due to the x-ray windows and the upper limit is due to the critical angle of the x-ray mirror. Two different coatings (Cr and Pt) for the x-ray mirror allow either 20 keV or 30 keV energy cutoff.

53

Temporal multiplexing radiography for dynamic x-ray imaging  

Science Conference Proceedings (OSTI)

All current x-ray imaging devices acquire images sequentially, one at a time. Using a spatially distributed multibeam x-ray source we recently demonstrated the feasibility for multiplexing x-ray imaging, which can significantly increase the data collection speed. Here we present a general methodology for dynamic x-ray imaging of an object in cyclic motion with temporal multiplexing. Compared to the conventional sequential imaging technique, where 2N-1 phase images are required and N exposures are needed for a single phase image, a temporal multiplexing of dimension 2N-1 can reduce the imaging time by a factor of N while maintaining the temporal resolution.

Cao Guohua [Department of Physics and Astronomy, University of North Carolina, Chapel Hill, North Carolina 27599 (United States); Zhang Jian [Department of Radiation Oncology and Department of Physics and Astronomy, University of North Carolina, Chapel Hill, North Carolina 27599 (United States); Zhou, Otto; Lu Jianping [Department of Physics and Astronomy and Curriculum in Applied Sciences and Engineering, University of North Carolina, Chapel Hill, North Carolina, 27599 (United States)

2009-09-15T23:59:59.000Z

54

Lensless X-Ray Imaging in Reflection  

NLE Websites -- All DOE Office Websites (Extended Search)

relevant to atomic and molecular phenomena) with the advantages of visible-light lasers (highly coherent beams). All of these characteristics are important for coherent x-ray...

55

Bruker Workshop on Single Crystal X-Ray Diffraction  

NLE Websites -- All DOE Office Websites (Extended Search)

Diagnosis and Treatment of Problem Structures: Diagnosis and Treatment of Problem Structures: A Bruker Workshop on Single Crystal X-Ray Diffraction May 30, 2008 Chemistry Department University of Tennessee Knoxville, TN This meeting focuses on the scientific resources of four ORNL user facilities funded by the DOE Office of Basic Energy Sciences. Who Should Attend Synopsis Goals Scheduled Agenda Workshop Materials Confirmed Speakers Important Dates Registration - now open Location - Directions and Map Sponsors Organizing and Local Committee Contacts Relevant Literature, References, Websites Local Information Bruker - UT Workshop Who Should Attend? The Workshop is directed to the newcomer as well as the experienced user of a Bruker Apex / Apex-II system and SHELX software. It will concentrate on hard to solve and/or refine problem structures. We envision it to be

56

Calibrating X-ray Imaging Devices for Accurate Intensity Measurement  

SciTech Connect

The purpose of the project presented is to develop methods to accurately calibrate X-ray imaging devices. The approach was to develop X-ray source systems suitable for this endeavor and to develop methods to calibrate solid state detectors to measure source intensity. NSTec X-ray sources used for the absolute calibration of cameras are described, as well as the method of calibrating the source by calibrating the detectors. The work resulted in calibration measurements for several types of X-ray cameras. X-ray camera calibration measured efficiency and efficiency variation over the CCD. Camera types calibrated include: CCD, CID, back thinned (back illuminated), front illuminated.

Haugh, M. J.

2011-07-28T23:59:59.000Z

57

X-ray image intensifier phosphor  

DOE Patents (OSTI)

Y/sub 1-x/Gd/sub x/.PO$sub 4$:Tb$sup 3+$ is an effective phosphor for use in X-ray intensifier screens and in nuclear radiation detection systems.

D' Silva, A.P.; Fassel, V.A.

1975-12-01T23:59:59.000Z

58

High Temperature X-ray Diffraction Characterization of Thermal ...  

Science Conference Proceedings (OSTI)

Application of Conical Beam X-Ray Tomography to Multi-Phase Materials ... Digital Construction and Characterization of Reticulated Porous Microstructures ...

59

Development of Coherent X-Ray Diffraction Microscopy and Its ...  

Science Conference Proceedings (OSTI)

About this Abstract. Meeting, 2010 TMS Annual Meeting & Exhibition. Symposium , Neutron and X-Ray Studies of Advanced Materials III. Presentation Title, 2010 ...

60

Model independent pre-processing of X-ray powder diffraction profiles  

Science Conference Proceedings (OSTI)

Precise knowledge of X-ray diffraction profile shape is crucial in the investigation of the properties of matter in crystals powder. Line-broadening analysis is the fourth pre-processing step in most of the full powder pattern fitting softwares. The ... Keywords: Hankel--Lanczos singular value decomposition (HLSVD), Morphological filtering, X-ray powder diffraction

M. Ladisa; A. Lamura; T. Laudadio; G. Nico

2007-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "x-ray diffraction imaging" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


61

X-Ray Imaging Crystal Spectrometer for Extended X-Ray Sources  

DOE Patents (OSTI)

Spherically or toroidally curved, double focusing crystals are used in a spectrometer for X-ray diagnostics of an extended X-ray source such as a hot plasma produced in a tokamak fusion experiment to provide spatially and temporally resolved data on plasma parameters such as ion temperature, toroidal and poloidal rotation, electron temperature, impurity ion charge-state distributions, and impurity transport. The imaging properties of these spherically or toroidally curved crystals provide both spectrally and spatially resolved X-ray data from the plasma using only one small spherically or toroidally curved crystal, thus eliminating the requirement for a large array of crystal spectrometers and the need to cross-calibrate the various crystals.

Bitter, Manfred L.; Fraekel, Benjamin; Gorman, James L.; Hill, Kenneth W.; Roquemore, Lane A.; Stodiek, Wolfgang; Goeler, Schweickhard von

1999-05-01T23:59:59.000Z

62

NEUTRON AND SYNCHROTRON X-RAY FIBER DIFFRACTION STUDIES OF CELLULOSE POLYMORPHS.  

DOE Green Energy (OSTI)

Although the crystalline nature of cellulose has been one of most studied structural problems in polymer science there remain many open questions. Cellulose is a polymer formed by (1-4)-linked {beta}-D-glucosyl residues that are alternately rotated by 180o along the polymer axis to form flat ribbon-like chains. Each glucosyl unit bears three hydroxyl groups, one an hydroxymethyl group. It has been long recognized that these hydroxyl groups and their ability to bond via hydrogen bonding not only play a major role in directing how the crystal structure of cellulose forms but also in governing important physical properties of cellulose materials. Through the development of new techniques we have been able to prepare fiber samples of cellulose with exceptionally high order. The quality of these samples is allowing us to exploit the unique properties of synchrotron X-ray and neutron sources in order to collect diffraction data to near atomic resolution. Synchrotron X-rays are used to provide accurate crystallographic parameters for C and O atoms. However, because of the relatively weak scattering power of H atoms for X-rays, neutrons are used to determine H atom parameters. We have developed methods for replacing labile H atoms with D, without any loss in crystalline perfection. Deuterated fibers can diffract neutrons with intensities that are substantially different from the intensities diffracted from hydrogenated fibers. These differences, along with the phases calculated from the C and O positions determined in our X-ray studies, are used to calculate Fourier difference syntheses in which density associated with labile hydrogen atoms is imaged. The unprecedented high resolution of these data is revealing new information on cellulose structure and hydrogen bonding.

Los Alamos National Laboratory

2001-01-01T23:59:59.000Z

63

Interferometric hard x-ray phase contrast imaging at 204 nm grating period  

SciTech Connect

We report on hard x-ray phase contrast imaging experiments using a grating interferometer of approximately 1/10th the grating period achieved in previous studies. We designed the gratings as a staircase array of multilayer stacks which are fabricated in a single thin film deposition process. We performed the experiments at 19 keV x-ray energy and 0.8 {mu}m pixel resolution. The small grating period resulted in clear separation of different diffraction orders and multiple images on the detector. A slitted beam was used to remove overlap of the images from the different diffraction orders. The phase contrast images showed detailed features as small as 10 {mu}m, and demonstrated the feasibility of high resolution x-ray phase contrast imaging with nanometer scale gratings.

Wen Han; Gomella, Andrew A.; Miao, Houxun; Lynch, Susanna K. [Imaging Physic Laboratory, Biophysics and Biochemistry Center, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, Maryland 20892 (United States); Wolfe, Douglas E. [Applied Research Laboratory, Penn State University, State College, Pennsylvania 16804 (United States); Xiao Xianghui; Liu Chian [X-Ray Science Division, Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Morgan, Nicole [National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, Maryland 20892 (United States)

2013-01-15T23:59:59.000Z

64

Real-time X-ray Diffraction Measurements of Shocked Polycrystalline Tin and Aluminum  

SciTech Connect

A new, fast, single-pulse x-ray diffraction (XRD) diagnostic for determining phase transitions in shocked polycrystalline materials has been developed. The diagnostic consists of a 37-stage Marx bank high-voltage pulse generator coupled to a needle-and-washer electron beam diode via coaxial cable, producing line and bremsstrahlung x-ray emission in a 35-ns pulse. The characteristic K? lines from the selected anodes of silver and molybdenum are used to produce the diffraction patterns, with thin foil filters employed to remove the characteristic K? line emission. The x-ray beam passes through a pinhole collimator and is incident on the sample with an approximately 3-mm by 6-mm spot and 1° full-width-half-maximum (FWHM) angular divergence in a Bragg-reflecting geometry. For the experiments described in this report, the angle between the incident beam and the sample surface was 8.5°. A Debye-Scherrer diffraction image was produced on a phosphor located 76 mm from the polycrystalline sample surface. The phosphor image was coupled to a charge-coupled device (CCD) camera through a coherent fiberoptic bundle. Dynamic single-pulse XRD experiments were conducted with thin foil samples of tin, shock loaded with a 1-mm vitreous carbon back window. Detasheet high explosive with a 2-mm-thick aluminum buffer was used to shock the sample. Analysis of the dynamic shock-loaded tin XRD images revealed a phase transformation of the tin beta phase into an amorphous or liquid state. Identical experiments with shock-loaded aluminum indicated compression of the face-centered-cubic (fcc) aluminum lattice with no phase transformation.

Dane V. Morgan, Don Macy, Gerald Stevens

2008-11-22T23:59:59.000Z

65

X-Ray Scattering Group, Condensed Matter Physics & Materials...  

NLE Websites -- All DOE Office Websites (Extended Search)

- Brookhaven National Laboratory, Upton, NY Beamline X1A2 - Soft x-ray diffraction and nano-imaging Beamline X17 - X-ray powder diffraction Beamline X22C - Resonant x-ray...

66

Single mimivirus particles intercepted and imaged with an X-ray laser  

DOE Data Explorer (OSTI)

These are the files used to reconstruct the images in the paper "Single Mimivirus particles intercepted and imaged with an X-ray laser". Besides the diffracted intensities, the Hawk configuration files used for the reconstructions are also provided. The files from CXIDB ID 1 are the pattern and configuration files for the pattern showed in Figure 2a in the paper.

Seibert, M. Marvin; Ekeberg, Tomas; Maia, Filipe R.N.C.

67

Single mimivirus particles intercepted and imaged with an X-ray laser  

DOE Data Explorer (OSTI)

These are the files used to reconstruct the images in the paper "Single Mimivirus particles intercepted and imaged with an X-ray laser". Besides the diffracted intensities, the Hawk configuration files used for the reconstructions are also provided. The files from CXIDB ID 2 are the pattern and configuration files for the pattern showed in Figure 2b in the paper.

Seibert, M. Marvin; Ekeberg, Tomas

68

Performance characteristics needed for protein crystal diffraction x-ray detectors.  

Science Conference Proceedings (OSTI)

During the 1990's, macromolecular crystallography became progressively more dependent on synchrotrons X-ray sources for diffraction data collection. Detectors of this diffraction data at synchrotrons beamlines have evolved over the decade, from film to image phosphor plates, and then to CCD systems. These changes have been driven by the data quality and quantity improvements each newer detector technology provided. The improvements have been significant. It is likely that newer detector technologies will be adopted at synchrotron beamlines for crystallographic diffraction data collection in the future, but these technologies will have to compete with existing CCD detector systems which are already excellent and are getting incrementally better in terms of size, speed, efficiency, and resolving power. Detector development for this application at synchrotrons must concentrate on making systems which are bigger and faster than CCDs and which can capture weak data more efficiently. And there is a need for excellent detectors which are less expensive than CCD systems.

Westbrook, E. M.

1999-09-21T23:59:59.000Z

69

High Energy X-ray Diffraction Microscopy Microstructure Mapping  

Science Conference Proceedings (OSTI)

P1-04: 3D Microstructural Characterization of Uranium Oxide as a Surrogate Nuclear ... P1-15: Gating System Optimisation Design Study of a Cast Automobile ... P2-27: Characterization of Carbonate Rocks through X-ray Microtomography.

70

Towards hard x-ray imaging at GHz frame rate  

SciTech Connect

Gigahertz (GHz) imaging using hard x-rays ( Greater-Than-Or-Equivalent-To 10 keV) can be useful to high-temperature plasma experiments, as well as research and applications using coherent photons from synchrotron radiation and x-ray free electron lasers. GHz framing rate can be achieved by using multiple cameras through multiplexing. The advantages and trade-offs of single-photon detection mode, when no more than one x-ray photon is detected per pixel, are given. Two possible paths towards x-ray imaging at GHz frame rates using a single camera are: (a) avalanche photodiode arrays of high-Z materials and (b) microchannel plate photomultipliers in conjunction with materials with large indices of refraction.

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

2012-10-15T23:59:59.000Z

71

Towards hard X-ray imaging at GHz frame rate  

Science Conference Proceedings (OSTI)

Gigahertz (GHz) imaging using hard X-rays ({approx}> 10 keV) can be useful to high-temperature plasma experiments, as well as research using coherent photons from synchrotron radiation and X-ray free electron lasers. GHz framing rate can be achieved by using multiple cameras through multiplexing. The advantages and trade-offs of single-photon detection mode, when no more than one X-ray photon is detected per pixel, are given. Two possible paths towards X-ray imaging at GHz frame rates using a single camera are (a) Avalanche photodiode arrays of high-Z materials and (b) Microchannel plate photomultipliers in conjunction with materials with large indices of refraction.

Wang, Zhehui [Los Alamos National Laboratory; Morris, Christopher [Los Alamos National Laboratory; Luo, Shengnian [Los Alamos National Laboratory; Kwiatkowski, Kris K. [Los Alamos National Laboratory; Kapustinsky, Jon S. [Los Alamos National Laboratory

2012-05-02T23:59:59.000Z

72

Dilation x-ray imager a new/faster gated x-ray imager for the NIF  

SciTech Connect

As the yield on implosion shots increases it is expected that the peak x-ray emission reduces to a duration with a FWHM as short as 20 ps for {approx}7 Multiplication-Sign 10{sup 18} neutron yield. However, the temporal resolution of currently used gated x-ray imagers on the NIF is 40-100 ps. We discuss the benefits of the higher temporal resolution for the NIF and present performance measurements for dilation x-ray imager, which utilizes pulse-dilation technology [T. J. Hilsabeck et al., Rev. Sci. Instrum. 81, 10E317 (2010)] to achieve x-ray imaging with temporal gate times below 10 ps. The measurements were conducted using the COMET laser, which is part of the Jupiter Laser Facility at the Lawrence Livermore National Laboratory.

Nagel, S. R.; Bell, P. M.; Bradley, D. K.; Ayers, M. J.; Barrios, M. A.; Felker, B.; Smith, R. F.; Collins, G. W.; Jones, O. S.; Piston, K.; Raman, K. S. [Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550 (United States); Hilsabeck, T. J.; Kilkenny, J. D.; Chung, T.; Sammuli, B. [General Atomics, P.O. Box 85608, San Diego, California 92186-5608 (United States); Hares, J. D.; Dymoke-Bradshaw, A. K. L. [Kentech Instruments Ltd., Wallingford, Oxfordshire OX10 (United Kingdom)

2012-10-15T23:59:59.000Z

73

Lattice motions from THz phonon-polaritons measured with femtosecond x-ray diffraction  

Science Conference Proceedings (OSTI)

We use femtosecond x-ray diffraction to measure the coherent lattice displacements associated with the excitation and propagation of THz phonon polaritons in LiTaO3.

Schoenlein, Robert William; Cavalleri, A.; Wall, S.; Simpson, C.; Statz, E.; Ward, D.W.; Nelson, K.A.; Schoenlein, R.W.; Rini, M.; Dean, N.; Khalil, M.

2006-08-07T23:59:59.000Z

74

Electrochemical in-situ reaction cell for X-ray scattering, diffraction and spectroscopy  

DOE Green Energy (OSTI)

An electrochemical in-situ reaction cell for hard X-ray experiments with battery electrodes is described. Applications include the small angle scattering, diffraction, and near-edge spectroscopy of lithium manganese oxide electrodes.

Braun, Artur; Granlund, Eric; Cairns, Elton J.

2003-01-27T23:59:59.000Z

75

Method for improving x-ray diffraction determinations of residual stress in nickel-base alloys  

DOE Patents (OSTI)

A process for improving the technique of measuring residual stress by x-ray diffraction in pieces of nickel-base alloys is discussed. Part of a predetermined area of the surface of a nickel-base alloy is covered with a dispersion. This exposes the covered and uncovered portions of the surface of the alloy to x-rays by way of an x-ray diffractometry apparatus, making x-ray diffraction determinations of the exposed surface, and measuring the residual stress in the alloy based on these determinations. The dispersion is opaque to x-rays and serves a dual purpose, since it masks off unsatisfactory signals such that only a small portion of the surface is measured, and it supplies an internal standard by providing diffractogram peaks comparable to the peaks of the nickel alloy so that the alloy peaks can be very accurately located regardless of any sources of error external to the sample. 2 figs.

Berman, R.M.; Cohen, I.

1988-04-26T23:59:59.000Z

76

X-ray Microscopy and Imaging (XSD-XMI)  

NLE Websites -- All DOE Office Websites (Extended Search)

Imaging (XMI) Imaging (XMI) About XMI Science and Research Beamlines Highlights Software and Tools Intranet Search APS... Argonne Home > Advanced Photon Source > Contacts FAQs Beamlines News Publications APS Email Portal APS Intranet APS Phonebook APS Quick Links for Users APS Safety and Training Welcome to the X-ray Microscopy and Imaging group (XMI)! X-ray Microscopy and Imaging is part of the X-ray Science Division at the Advanced Photon Source. We develop and support a diverse and multidisciplinary user research program at Sectors 2 and 32 of the APS, with the overall goal to image and study materials structures at spatial and temporal resolutions that are most scientifically relevant to the cutting-edge advances in materials, biological, environmental, and biomedical sciences. To achieve this goal, we actively engage in various research activities including

77

Restoration of X-ray fluorescence images of hidden paintings  

Science Conference Proceedings (OSTI)

This paper describes our methods for repairing and restoring images of hidden paintings (paintings that have been painted over and are now covered by a new surface painting) that have been obtained via noninvasive X-ray fluorescence imaging of their ... Keywords: Art restoration, Artifact correction, Image restoration, Underdetermined source separation

Anila Anitha; Andrei Brasoveanu; Marco Duarte; Shannon Hughes; Ingrid Daubechies; Joris Dik; Koen Janssens; Matthias Alfeld

2013-03-01T23:59:59.000Z

78

Lensless Imaging of Whole Biological Cells with Soft X-Rays  

NLE Websites -- All DOE Office Websites (Extended Search)

Lensless Imaging of Whole Lensless Imaging of Whole Biological Cells with Soft X-Rays Lensless Imaging of Whole Biological Cells with Soft X-Rays Print Wednesday, 26 May 2010 00:00 A team of scientists has used x-ray diffraction microscopy at ALS Beamline 9.0.1 to make images of whole yeast cells, achieving the highest resolution-11 to 13 nanometers (billionths of a meter)-ever obtained with this method for biological specimens. Their success indicates that full 3-D tomography of whole cells at equivalent resolution should soon be possible. The National Center for X-Ray Tomography at ALS Beamline 2.1 images whole, frozen hydrated cells in 3-D (see highlight "Imaging Antifungal Drug Molecules in Action using Soft X-Ray Tomography"). Large numbers of cells can currently be processed in a short time at resolutions of 40 to 60 nanometers, but the ability to increase resolution to the 10-nanometer range would enhance research capabilities in both biology and materials sciences.

79

Lensless Imaging of Whole Biological Cells with Soft X-Rays  

NLE Websites -- All DOE Office Websites (Extended Search)

Lensless Imaging of Whole Biological Cells with Soft X-Rays Print Lensless Imaging of Whole Biological Cells with Soft X-Rays Print A team of scientists has used x-ray diffraction microscopy at ALS Beamline 9.0.1 to make images of whole yeast cells, achieving the highest resolution-11 to 13 nanometers (billionths of a meter)-ever obtained with this method for biological specimens. Their success indicates that full 3-D tomography of whole cells at equivalent resolution should soon be possible. The National Center for X-Ray Tomography at ALS Beamline 2.1 images whole, frozen hydrated cells in 3-D (see highlight "Imaging Antifungal Drug Molecules in Action using Soft X-Ray Tomography"). Large numbers of cells can currently be processed in a short time at resolutions of 40 to 60 nanometers, but the ability to increase resolution to the 10-nanometer range would enhance research capabilities in both biology and materials sciences.

80

Lensless Imaging of Whole Biological Cells with Soft X-Rays  

NLE Websites -- All DOE Office Websites (Extended Search)

Lensless Imaging of Whole Biological Cells with Soft X-Rays Print Lensless Imaging of Whole Biological Cells with Soft X-Rays Print A team of scientists has used x-ray diffraction microscopy at ALS Beamline 9.0.1 to make images of whole yeast cells, achieving the highest resolution-11 to 13 nanometers (billionths of a meter)-ever obtained with this method for biological specimens. Their success indicates that full 3-D tomography of whole cells at equivalent resolution should soon be possible. The National Center for X-Ray Tomography at ALS Beamline 2.1 images whole, frozen hydrated cells in 3-D (see highlight "Imaging Antifungal Drug Molecules in Action using Soft X-Ray Tomography"). Large numbers of cells can currently be processed in a short time at resolutions of 40 to 60 nanometers, but the ability to increase resolution to the 10-nanometer range would enhance research capabilities in both biology and materials sciences.

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81

Lensless Imaging of Whole Biological Cells with Soft X-Rays  

NLE Websites -- All DOE Office Websites (Extended Search)

Lensless Imaging of Whole Biological Cells with Soft X-Rays Print Lensless Imaging of Whole Biological Cells with Soft X-Rays Print A team of scientists has used x-ray diffraction microscopy at ALS Beamline 9.0.1 to make images of whole yeast cells, achieving the highest resolution-11 to 13 nanometers (billionths of a meter)-ever obtained with this method for biological specimens. Their success indicates that full 3-D tomography of whole cells at equivalent resolution should soon be possible. The National Center for X-Ray Tomography at ALS Beamline 2.1 images whole, frozen hydrated cells in 3-D (see highlight "Imaging Antifungal Drug Molecules in Action using Soft X-Ray Tomography"). Large numbers of cells can currently be processed in a short time at resolutions of 40 to 60 nanometers, but the ability to increase resolution to the 10-nanometer range would enhance research capabilities in both biology and materials sciences.

82

Lensless Imaging of Whole Biological Cells with Soft X-Rays  

NLE Websites -- All DOE Office Websites (Extended Search)

Lensless Imaging of Whole Biological Cells with Soft X-Rays Print Lensless Imaging of Whole Biological Cells with Soft X-Rays Print A team of scientists has used x-ray diffraction microscopy at ALS Beamline 9.0.1 to make images of whole yeast cells, achieving the highest resolution-11 to 13 nanometers (billionths of a meter)-ever obtained with this method for biological specimens. Their success indicates that full 3-D tomography of whole cells at equivalent resolution should soon be possible. The National Center for X-Ray Tomography at ALS Beamline 2.1 images whole, frozen hydrated cells in 3-D (see highlight "Imaging Antifungal Drug Molecules in Action using Soft X-Ray Tomography"). Large numbers of cells can currently be processed in a short time at resolutions of 40 to 60 nanometers, but the ability to increase resolution to the 10-nanometer range would enhance research capabilities in both biology and materials sciences.

83

Lensless Imaging of Whole Biological Cells with Soft X-Rays  

NLE Websites -- All DOE Office Websites (Extended Search)

Lensless Imaging of Whole Biological Cells with Soft X-Rays Print Lensless Imaging of Whole Biological Cells with Soft X-Rays Print A team of scientists has used x-ray diffraction microscopy at ALS Beamline 9.0.1 to make images of whole yeast cells, achieving the highest resolution-11 to 13 nanometers (billionths of a meter)-ever obtained with this method for biological specimens. Their success indicates that full 3-D tomography of whole cells at equivalent resolution should soon be possible. The National Center for X-Ray Tomography at ALS Beamline 2.1 images whole, frozen hydrated cells in 3-D (see highlight "Imaging Antifungal Drug Molecules in Action using Soft X-Ray Tomography"). Large numbers of cells can currently be processed in a short time at resolutions of 40 to 60 nanometers, but the ability to increase resolution to the 10-nanometer range would enhance research capabilities in both biology and materials sciences.

84

Lensless Imaging of Whole Biological Cells with Soft X-Rays  

NLE Websites -- All DOE Office Websites (Extended Search)

Lensless Imaging of Whole Biological Cells with Soft X-Rays Print Lensless Imaging of Whole Biological Cells with Soft X-Rays Print A team of scientists has used x-ray diffraction microscopy at ALS Beamline 9.0.1 to make images of whole yeast cells, achieving the highest resolution-11 to 13 nanometers (billionths of a meter)-ever obtained with this method for biological specimens. Their success indicates that full 3-D tomography of whole cells at equivalent resolution should soon be possible. The National Center for X-Ray Tomography at ALS Beamline 2.1 images whole, frozen hydrated cells in 3-D (see highlight "Imaging Antifungal Drug Molecules in Action using Soft X-Ray Tomography"). Large numbers of cells can currently be processed in a short time at resolutions of 40 to 60 nanometers, but the ability to increase resolution to the 10-nanometer range would enhance research capabilities in both biology and materials sciences.

85

Lensless Imaging of Whole Biological Cells with Soft X-Rays  

NLE Websites -- All DOE Office Websites (Extended Search)

Lensless Imaging of Whole Biological Cells with Soft X-Rays Print Lensless Imaging of Whole Biological Cells with Soft X-Rays Print A team of scientists has used x-ray diffraction microscopy at ALS Beamline 9.0.1 to make images of whole yeast cells, achieving the highest resolution-11 to 13 nanometers (billionths of a meter)-ever obtained with this method for biological specimens. Their success indicates that full 3-D tomography of whole cells at equivalent resolution should soon be possible. The National Center for X-Ray Tomography at ALS Beamline 2.1 images whole, frozen hydrated cells in 3-D (see highlight "Imaging Antifungal Drug Molecules in Action using Soft X-Ray Tomography"). Large numbers of cells can currently be processed in a short time at resolutions of 40 to 60 nanometers, but the ability to increase resolution to the 10-nanometer range would enhance research capabilities in both biology and materials sciences.

86

Lensless Imaging of Whole Biological Cells with Soft X-Rays  

NLE Websites -- All DOE Office Websites (Extended Search)

Lensless Imaging of Whole Biological Cells with Soft X-Rays Print Lensless Imaging of Whole Biological Cells with Soft X-Rays Print A team of scientists has used x-ray diffraction microscopy at ALS Beamline 9.0.1 to make images of whole yeast cells, achieving the highest resolution-11 to 13 nanometers (billionths of a meter)-ever obtained with this method for biological specimens. Their success indicates that full 3-D tomography of whole cells at equivalent resolution should soon be possible. The National Center for X-Ray Tomography at ALS Beamline 2.1 images whole, frozen hydrated cells in 3-D (see highlight "Imaging Antifungal Drug Molecules in Action using Soft X-Ray Tomography"). Large numbers of cells can currently be processed in a short time at resolutions of 40 to 60 nanometers, but the ability to increase resolution to the 10-nanometer range would enhance research capabilities in both biology and materials sciences.

87

High Quality Image of Biomedical Object by X-ray Refraction Based Contrast Computed Tomography  

SciTech Connect

Recently we have developed a new Computed Tomography (CT) algorithm for refraction contrast that uses the optics of diffraction-enhanced imaging. We applied this new method to visualize soft tissue which is not visualized by the current absorption based contrast. The meaning of the contrast that appears in refraction-contrast X-ray CT images must be clarified from a biologic or anatomic point of view. It has been reported that the contrast is made with the specific gravity map with a range of approximately 10 {mu}arc sec. However, the relationship between the contrast and biologic or anatomic findings has not been investigated, to our knowledge. We compared refraction-contrast X-ray CT images with microscopic X-ray images, and we evaluated refractive indexes of pathologic lesions on phase-contrast X-ray CT images. We focused our attenuation of breast cancer and lung cancer as samples. X-ray refraction based Computed Tomography was appeared to be a pathological ability to depict the boundary between cancer nest and normal tissue, and inner structure of the disease.

Hashimoto, E. [Department of Photon-Science, School of Advanced Studies, Graduate University for Advanced Studies (GUAS), Shonan Village, Hayama, Kanagawa 240-0193 (Japan); Maksimenko, A.; Hirano, K.; Hyodo, K. [Photon Factory, Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK), 1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan); Sugiyama, H. [Department of Photon-Science, School of Advanced Studies, Graduate University for Advanced Studies (GUAS), Shonan Village, Hayama, Kanagawa 240-0193 (Japan); Photon Factory, Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK), 1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan); Shimao, D. [Department of Health Sciences, Ibaraki prefectural University of Health Sciences, 4669-2Ami, Ami, Inashiki, Ibaraki, 300-0394 (Japan); Nishino, Y.; Ishikawa, T. [RIKEN Harima Institute, 1-1-1 Kouto, Mikazuki, Sayo, Hyogo, 679-5148 (Japan); Yuasa, T. [Department of Bio-system Engineering, Faculty of Engineering Yamagata University, 4-3-16 Jonan, Yonezawa, Yamagata 992-8510 (Japan); Ichihara, S. [Dept. of Path., Nagoya Med. Center, Nat. Hospital Organization, Naka-ku, Nagoya 460-0001 (Japan); Arai, Y. [Matsumoto Dental University, 1980 Hirooka, Shiojiri, Nagano (Japan); Ando, M. [Department of Photon-Science, School of Advanced Studies, Graduate University for Advanced Studies (GUAS), Shonan Village, Hayama, Kanagawa 240-0193 (Japan); Photon Factory, Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK), 1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan); Inst. of Sci. and Tech., Tokyo Univ. of Science, Yamasaki 2641, Noda, Chiba 278-8510 (Japan)

2007-01-19T23:59:59.000Z

88

Quantitative determination of mineral composition by powder x-ray diffraction  

DOE Patents (OSTI)

An external standard intensity ratio method is used for quantitatively determining mineralogic compositions of samples by x-ray diffraction. The method uses ratios of x-ray intensity peaks from a single run. Constants are previously determined for each mineral which is to be quantitatively measured. Ratios of the highest intensity peak of each mineral to be quantified in the sample and the highest intensity peak of a reference mineral contained in the sample are used to calculate sample composition.

Pawloski, G.A.

1984-08-10T23:59:59.000Z

89

Quantitative determination of mineral composition by powder X-ray diffraction  

DOE Patents (OSTI)

An external standard intensity ratio method is used for quantitatively determining mineralogic compositions of samples by x-ray diffraction. The method uses ratios of x-ray intensity peaks from a single run. Constants are previously determined for each mineral which is to be quantitatively measured. Ratios of the highest intensity peak of each mineral to be quantified in the sample and the highest intensity peak of a reference mineral contained in the sample are used to calculate sample composition.

Pawloski, Gayle A. (Livermore, CA)

1986-01-01T23:59:59.000Z

90

Segmentation of x-ray images using Probabilistic Relaxation Labeling  

SciTech Connect

Segmentation is a process of separating objects of interest from their background or from other objects in an image. Without a suitable segmentation scheme, it is very difficult to detect contraband in X-rays images. In this paper, a Probabilistic Relaxation Labeling (PRL) segmentation scheme is presented and compared with other segmentation methods. PRL segmentation is an interative algorithm that labels each pixel in an image by cooperative use of two information sources: the pixel probability and the degree of certainty of its probability supported by the neighboring pixels. The practical implementation and results of the PRL segmentation on X-ray baggage images are also discussed and compared with other segmentation methods. 13 refs., 12 figs.

Thai, T.Q.

1991-01-01T23:59:59.000Z

91

Diffraction crystals for sagittally focusing x-rays  

DOE Patents (OSTI)

The invention is a new type of diffraction crystal designed for sagittally focusing photons of various energies. The invention is based on the discovery that such focusing is not obtainable with conventional crystals because of distortion resulting from anticlastic curvature. The new crystal comprises a monocrystalline base having a front face contoured for sagittally focusing photons and a back face provided with rigid, upstanding, stiffening ribs restricting anticlastic curvature. When mounted in a suitable bending device, the reflecting face of the crystal can be adjusted to focus photons having any one of a range of energies.

Ice, G.E.; Sparks, C.J. Jr.

1982-06-07T23:59:59.000Z

92

Diffraction crystal for sagittally focusing x-rays  

DOE Patents (OSTI)

The invention is a new type of diffraction crystal designed for sagittally focusing photons of various energies. The invention is based on the discovery that such focusing is not obtainable with conventional crystals because of distortion resulting from anticlastic curvature. The new crystal comprises a monocrystalline base having a front face contoured for sagittally focusing photons and a back face provided with rigid, upstanding, stiffening ribs restricting anticlastic curvature. When mounted in a suitable bending device, the reflecting face of the crystal can be adjusted to focus photons having any one of a range of energies.

Ice, Gene E. (Oak Ridge, TN); Sparks, Jr., Cullie J. (Oak Ridge, TN)

1984-01-01T23:59:59.000Z

93

In situ X-ray diffraction study of thin film Ir/Si solid state reactions  

Science Conference Proceedings (OSTI)

The solid state reaction between a thin (30nm) Ir film and different Si substrates (p-type Si(100), n- and p-type Si(111), silicon on insulator (SOI) and polycrystalline Si) was studied using a combination of in situ X-ray diffraction (XRD), in situ ... Keywords: Ir, NiSi, Si, XRD

W. Knaepen; J. Demeulemeester; D. Deduytsche; J. L. Jordan-Sweet; A. Vantomme; R. L. Van Meirhaeghe; C. Detavernier; C. Lavoie

2010-03-01T23:59:59.000Z

94

Investigation of Renal Stones by X-ray and Neutron Diffraction  

SciTech Connect

Renal stones were investigated by X-ray diffraction. The obtained results showed only one crystal phase in every sample. With the aim to verify eventual availability of second phase (under 3 volume %) the same renal stones were investigated by neutron diffraction. The neutron spectra proved that additional crystal phase was absent in the renal stones. The obtained results are scientific-practical, in aid of the medicine, especially in the case of renal stone disease.

Baeva, M.; Boianova, A. [Institute of Solid State Physics-BAS, 1784 Sofia (Bulgaria); Beskrovnyi, A. I.; Shelkova, I. [Joint Institute of Nuclear Research, Dubna (Russian Federation)

2007-04-23T23:59:59.000Z

95

Beyond 3-D X-ray Imaging: Methodology Development and Applications in  

NLE Websites -- All DOE Office Websites (Extended Search)

Beyond 3-D X-ray Imaging: Methodology Development and Applications in Beyond 3-D X-ray Imaging: Methodology Development and Applications in Material Science Thursday, September 6, 2012 - 10:45am SLAC, Bldg. 137, Room 226 Yijin Liu Seminar There was a revolutionary development of X-ray imaging over the past few decades. The most substantial advancements in this field are closely related to the availability of the new generation of X-ray sources and the advanced X-ray optics. The advanced X-ray Optics along with novel methodology has made it possible to extract information that is related to different interactions between the X-rays and the specimen at very fine spatial resolution. The energy tunability of the X-rays has made it possible to combine the energy scan with imaging technique. And the brilliance of the X-ray source has made it practical for many sophisticated

96

XIPE: the X-ray Imaging Polarimetry Explorer  

E-Print Network (OSTI)

X-ray polarimetry, sometimes alone, and sometimes coupled to spectral and temporal variability measurements and to imaging, allows a wealth of physical phenomena in astrophysics to be studied. X-ray polarimetry investigates the acceleration process, for example, including those typical of magnetic reconnection in solar flares, but also emission in the strong magnetic fields of neutron stars and white dwarfs. It detects scattering in asymmetric structures such as accretion disks and columns, and in the so-called molecular torus and ionization cones. In addition, it allows fundamental physics in regimes of gravity and of magnetic field intensity not accessible to experiments on the Earth to be probed. Finally, models that describe fundamental interactions (e.g. quantum gravity and the extension of the Standard Model) can be tested. We describe in this paper the X-ray Imaging Polarimetry Explorer (XIPE), proposed in June 2012 to the first ESA call for a small mission with a launch in 2017 but not selected. XIPE ...

Soffitta, Paolo; Bellazzini, Ronaldo; Braga, João; Costa, Enrico; Fraser, George W; Gburek, Szymon; Huovelin, Juhani; Matt, Giorgio; Pearce, Mark; Poutanen, Juri; Reglero, Victor; Santangelo, Andrea; Sunyaev, Rashid A; Tagliaferri, Gianpiero; Weisskopf, Martin; Aloisio, Roberto; Amato, Elena; Attiná, Primo; Axelsson, Magnus; Baldini, Luca; Basso, Stefano; Bianchi, Stefano; Blasi, Pasquale; Bregeon, Johan; Brez, Alessandro; Bucciantini, Niccoló; Burderi, Luciano; Burwitz, Vadim; Casella, Piergiorgio; Churazov, Eugene; Civitani, Marta; Covino, Stefano; da Silva, Rui Miguel Curado; Cusumano, Giancarlo; Dadina, Mauro; D'Amico, Flavio; De Rosa, Alessandra; Di Cosimo, Sergio; Di Persio, Giuseppe; Di Salvo, Tiziana; Dovciak, Michal; Elsner, Ronald; Eyles, Chris J; Fabian, Andrew C; Fabiani, Sergio; Feng, Hua; Giarrusso, Salvatore; Goosmann, René W; Grandi, Paola; Grosso, Nicolas; Israel, Gianluca; Jackson, Miranda; Kaaret, Philip; Karas, Vladimir; Kuss, Michael; Lai, Dong; La Rosa, Giovanni; Larsson, Josefin; Larsson, Stefan; Latronico, Luca; Maggio, Antonio; Maia, Jorge; Marin, Frédéric; Massai, Marco Maria; Mineo, Teresa; Minuti, Massimo; Moretti, Elena; Muleri, Fabio; O'Dell, Stephen L; Pareschi, Giovanni; Peres, Giovanni; Pesce, Melissa; Petrucci, Pierre-Olivier; Pinchera, Michele; Porquet, Delphine; Ramsey, Brian; Rea, Nanda; Reale, Fabio; Rodrigo, Juana Maria; Ró?a?ska, Agata; Rubini, Alda; Rudawy, Pawel; Ryde, Felix; Salvati, Marco; Júnior, Valdivino Alexandre de Santiago; Sazonov, Sergey; Sgró, Carmelo; Silver, Eric; Spandre, Gloria; Spiga, Daniele; Stella, Luigi; Tamagawa, Toru; Tamborra, Francesco; Tavecchio, Fabrizio; Dias, Teresa Teixeira; van Adelsberg, Matthew; Wu, Kinwah; Zane, Silvia

2013-01-01T23:59:59.000Z

97

Fiber fed x-ray/gamma ray imaging apparatus  

SciTech Connect

X-ray/gamma ray imaging apparatus is disclosed for detecting the position, energy, and intensity of x-ray/gamma ray radiation comprising scintillation means disposed in the path of such radiation and capable of generating photons in response to such radiation; first photodetection means optically bonded to the scintillation means and capable of generating an electrical signal indicative of the intensity, and energy of the radiation detected by the scintillation means; second photodetection means capable of generating an electrical signal indicative of the position of the radiation in the radiation pattern; and means for optically coupling the scintillation means to the second photodetection means. The photodetection means are electrically connected to control and storage means which may also be used to screen out noise by rejecting a signal from one photodetection means not synchronized to a signal from the other photodetection means; and also to screen out signals from scattered radiation.

Hailey, Charles J. (San Francisco, CA); Ziock, Klaus-Peter (Livermore, CA)

1992-01-01T23:59:59.000Z

98

A laboratory based system for Laue micro x-ray diffraction  

SciTech Connect

A laboratory diffraction system capable of illuminating individual grains in a polycrystalline matrix is described. Using a microfocus x-ray source equipped with a tungsten anode and prefigured monocapillary optic, a micro-x-ray diffraction system with a 10 mum beam was developed. The beam profile generated by the ellipsoidal capillary was determined using the"knife edge" approach. Measurement of the capillary performance, indicated a beam divergence of 14 mrad and a useable energy bandpass from 5.5 to 19 keV. Utilizing the polychromatic nature of the incident x-ray beam and application of the Laue indexing software package X-Ray Micro-Diffraction Analysis Software, the orientation and deviatoric strain of single grains in a polycrystalline material can be studied. To highlight the system potential the grain orientation and strain distribution of individual grains in a polycrystalline magnesium alloy (Mg 0.2 wt percent Nd) was mapped before and after tensile loading. A basal (0002) orientation was identified in the as-rolled annealed alloy; after tensile loading some grains were observed to undergo an orientation change of 30 degrees with respect to (0002). The applied uniaxial load was measured as an increase in the deviatoric tensile strain parallel to the load axis (37 References).

Advanced Light Source; Tamura, Nobumichi; Lynch, P.A.; Stevenson, A.W.; Liang, D.; Parry, D.; Wilkins, S.; Tamura, N.

2007-02-28T23:59:59.000Z

99

The catalytic mechanism of an aspartic proteinase explored with neutron and X-ray diffraction  

DOE Green Energy (OSTI)

Hydrogen atoms play key roles in enzyme mechanism, but as this study shows, even high-quality X-ray data to a resolution of 1 {angstrom} cannot directly visualize them. Neutron diffraction, however, can locate deuterium atoms even at resolutions around 2 {angstrom}. Both neutron and X-ray diffraction data have been used to investigate the transition state of the aspartic proteinase endothiapepsin. The different techniques reveal a different part of the story, revealing the clearest picture yet of the catalytic mechanism by which the enzyme operates. Room temperature neutron and X-ray diffraction data were used in a newly developed joint refinement software package to visualize deuterium atoms within the active site of the enzyme when a gem-diol transition state analogue inhibitor is bound at the active site. These data were also used to estimate their individual occupancy, while analysis of the differences between the bond lengths of the catalytic aspartates was performed using atomic resolution X-ray data. The two methods are in agreement on the protonation state of the active site with a transition state analogue inhibitor bound confirming the catalytic mechanism at which the enzyme operates.

Kovalevsky, Andrey [Los Alamos National Laboratory (LANL); Erskine, Peter T. [University of Southampton, England; Cooper, Jon [University of Southampton, England

2008-01-01T23:59:59.000Z

100

Experimental validation of a radiographic simulation code using breast phantom for X-ray imaging  

Science Conference Proceedings (OSTI)

Computer models and simulations of X-ray imaging systems are becoming a very precious tool during the development and evaluation of new X-ray imaging techniques. To provide, however, a faithful simulation of a system, all components must be accurately ... Keywords: Breast phantoms, Experimental verification, Synchrotron radiation, X-ray imaging simulation

K. Bliznakova; R. Speller; J. Horrocks; P. Liaparinos; Z. Kolitsi; N. Pallikarakis

2010-02-01T23:59:59.000Z

Note: This page contains sample records for the topic "x-ray diffraction imaging" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


101

Design of a triaxial residual stress measurement system using high energy x-ray diffraction  

Science Conference Proceedings (OSTI)

Previous design studies in developing concepts for residual stress measurement in engineering materials have been extended. A pre-prototype energy dispersive x-ray diffraction (EDXRD) system has been fabricated. A 300 kV radiography source is used in conjunction with an intrinsic germanium detector and a MacII/LabVIEW data acquisition system. Specimens up to 25mm equivalent steel thickness (and one meter gross dimensions) can now be evaluated. The pre-prototype system serves as the hard x-ray, bulk stress measurement component of the previously reported hybrid stress measuring system (which would include a traditional multi-angle surface measurement system using soft x-rays). In addition, a detailed study of residual stress analytical equations has been completed and applied to various metallic and ceramic materials. During the grant period, related studies were completed on stress measurement using synchrotron radiation and on a critical review of the residual stress literature. 6 refs., 3 figs.

Shackelford, J.F.; Brown, B.D.; Park, J.S.

1989-01-01T23:59:59.000Z

102

Real-time Studies of Shocked Polycrystalline Materials with Single-Pulse X-ray Diffraction  

Science Conference Proceedings (OSTI)

Characteristic K-? x-rays used for single-pulse XRD are conventionally produced by a 37-stage high-voltage Marx pulse generator coupled to a vacuum needle-and-washer x-ray diode via coaxial transmission line. A large field-of-view x-ray image plate detection system typically enables observation of several Debye-Scherrer rings. Recently, we have developed a fiber-optic reducer, coupled to a CCD camera, to obtain low-noise, large field-of-view images. The direct beam spot is produced by bremsstrahlung radiation attenuated by a twomillimeter tungsten beam stop. Determination of the direct beam position is necessary to perform the ring integration.

Dane V. Morgan

2011-05-25T23:59:59.000Z

103

Imaging of micro-and nano-structures with hard X-rays  

E-Print Network (OSTI)

object with the hard X-ray microscope A horizontal line profile is inserted in the upper right partImaging of micro- and nano-structures with hard X-rays C. Rau, V. Crecea, C.-P. Richter, K Abstract: Imaging of micro- and nano-structures of opaque samples is demonstrated using hard X-rays. Two

Braun, Paul

104

Metrological characterization of X-ray diffraction methods for determination of crystallite size in nano-scale materials  

SciTech Connect

Crystallite size values were determined by X-ray diffraction methods for 210 TiO{sub 2} (anatase) nanocrystalline powders with crystallite size from 3 nm to 35 nm. Each X-ray diffraction pattern was processed using different free and commercial software. The crystallite size calculations were performed using Scherrer equation and Warren-Averbach method. Statistical treatment and comparative assessment of the obtained results were performed for the purpose of an ascertainment of statistical significance of the obtained differences. The average absolute divergence between results obtained with using Scherrer equation does not exceed 0.36 nm for the crystallites smaller than 10 nm, 0.54 nm for the range 10-15 nm and 2.4 nm for the range > 15 nm. We have also found that increasing the analysis time improves statistics, however does not affect the calculated crystallite sizes. The values of crystallite size determined from X-ray data were in good agreement with those obtained by imaging in a transmission electron microscope.

Uvarov, V. [Hebrew University of Jerusalem, Faculty of Natural Science, Center for Nanoscience and Nanotechnology, Unit for Nanoscopic Characterization, E. Safra Campus, Givat Ram, Jerusalem, 91904 (Israel)], E-mail: vladimiru@savion.huji.ac.il; Popov, I. [Hebrew University of Jerusalem, Faculty of Natural Science, Center for Nanoscience and Nanotechnology, Unit for Nanoscopic Characterization, E. Safra Campus, Givat Ram, Jerusalem, 91904 (Israel)

2007-10-15T23:59:59.000Z

105

High-Energy X-ray Diffraction Study of Internal Stresses in Metal Matrix  

NLE Websites -- All DOE Office Websites (Extended Search)

High-Energy X-ray Diffraction Study of Internal Stresses in Metal Matrix High-Energy X-ray Diffraction Study of Internal Stresses in Metal Matrix Composites Metal matrix composites (MMCs) comprise an intriguing new class of materials coming to prominence in the aerospace, electronics, and automotive industries. Internal stresses play an important role in the behavior and successful application of MMCs and multi-phase alloys. These stresses form during processing and service due to transformation or thermal expansion mismatch, as well as elastic and plastic mismatch during deformation. In order to develop a deeper understanding of the thermo-mechanical behavior of these materials, it is of key interest to examine the development of mean stresses in the phases of the composite as a function of time upon changes of temperature and/or external load.

106

X-ray diffraction study of residual stress in model weldments. Final report  

Science Conference Proceedings (OSTI)

Residual stress in a model weldment in nickel plate was characterized using x-ray diffraction techniques. The stress was mapped in 2 mm divisions up to the boundary of the weld pool. Results were in generally good agreement with the stress levels previously predicted for this system by finite element studies at LLNL. Recommendations are made that would permit 1 mm/sup 2/ spatial resolution maps of residual stress in stainless steel weldments.

Stroud, R.D.; Shackelford, J.F.

1980-11-01T23:59:59.000Z

107

Elimination of higher-order diffraction using zigzag transmission grating in soft x-ray region  

Science Conference Proceedings (OSTI)

We present a realization of the sinusoidal transmission function using a series of zigzag-profiled strips where the transmission takes on the binary values 0 and 1 in a two-dimensional distribution. A zigzag transmission grating of 1000 line/mm has been fabricated and demonstrated on the soft x-ray beam of synchrotron radiation. The axial single-order diffraction indicates that the zigzag transmission grating is adequate for spectroscopic application.

Zang, H. P.; Wang, C. K. [Research Center of Laser Fusion, China Academy of Engineering Physics, Mianyang, Sichuan 621900 (China); Institute of Atomic and Molecular Physics, Sichuan University, Chengdu 610065 (China); Gao, Y. L.; Zhou, W. M.; Kuang, L. Y.; Wei, L.; Fan, W.; Zhang, W. H.; Zhao, Z. Q.; Cao, L. F.; Gu, Y. Q.; Zhang, B. H. [Research Center of Laser Fusion, China Academy of Engineering Physics, Mianyang, Sichuan 621900 (China); Jiang, G. [Institute of Atomic and Molecular Physics, Sichuan University, Chengdu 610065 (China); Zhu, X. L.; Xie, C. Q. [Institute of Microelectronics, Chinese Academy of Sciences, Beijing 100029 (China); Zhao, Y. D.; Cui, M. Q. [Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China)

2012-03-12T23:59:59.000Z

108

Surface x-ray speckles : coherent surface diffraction from Au(0 01).  

Science Conference Proceedings (OSTI)

We present coherent speckled x-ray diffraction patterns obtained from a monolayer of surface atoms. We measured both the specular anti-Bragg reflection and the off-specular hexagonal reconstruction peak for the Au(001) surface reconstruction. We observed fluctuations of the speckle patterns even when the integrated intensity appears static. By autocorrelating the speckle patterns, we were able to identify two qualitatively different surface dynamic behaviors of the hex reconstruction depending on the sample temperature.

Pierce, M. S.; Chang, K. C.; Hennessy, D.; Komanicky, V.; Sprung, M.; Sandy, A.; You, H.; Safarik Univ.; HASYLAB

2009-10-16T23:59:59.000Z

109

High-speed X-ray Full-field Imaging Applications at the APS  

Science Conference Proceedings (OSTI)

Presentation Title, High-speed X-ray Full-field Imaging Applications at the APS ... Advances in Orientation Imaging Microscopy in Transmission Electron ...

110

X-ray Imaging Shows Feather Patterns of First Birds | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

X-ray Imaging Shows Feather Patterns of First Birds X-ray Imaging Shows Feather Patterns of First Birds X-ray Imaging Shows Feather Patterns of First Birds June 30, 2011 - 2:56pm Addthis A collage of images. Top, optical images of: blue jay feather, squid, and fossil fish with feather. Bottom: x-ray images showing the distribution of copper (red) in the same organisms. | Photo Courtesy of Gregory Stewart, SLAC National Accelerator Laboratory A collage of images. Top, optical images of: blue jay feather, squid, and fossil fish with feather. Bottom: x-ray images showing the distribution of copper (red) in the same organisms. | Photo Courtesy of Gregory Stewart, SLAC National Accelerator Laboratory Niketa Kumar Niketa Kumar Public Affairs Specialist, Office of Public Affairs What are the key facts? Through x-ray fluorescent imaging techniques developed at the

111

Combined use of hard X-ray phase contrast imaging and X-ray fluorescence microscopy for sub-cellular metal quantification  

E-Print Network (OSTI)

Combined use of hard X-ray phase contrast imaging and X-ray fluorescence microscopy for subSurface Science Laboratory at the European Synchrotron Radiation Facility, Grenoble, France Abstract Hard X of the details of cells are undetectable in hard X-ray microscopy due to the weak absorption contrast between

Paris-Sud XI, Université de

112

In Situ High-Pressure X-ray Diffraction Study of H2O Ice VII  

DOE Green Energy (OSTI)

Ice VII was examined over the entire range of its pressure stability by a suite of x-ray diffraction techniques in order to understand a number of unexplained characteristics of its high-pressure behavior. Axial and radial polycrystalline (diamond anvil cell) x-ray diffraction measurements reveal a splitting of diffraction lines accompanied by changes in sample texture and elastic anisotropy. In situ laser heating of polycrystalline samples resulted in the sharpening of diffraction peaks due to release of nonhydrostatic stresses but did not remove the splitting. Radial diffraction measurements indicate changes in strength of the material at this pressure. Taken together, these observations provide evidence for a transition in ice VII near 14 GPa involving changes in the character of the proton order/disorder. The results are consistent with previous reports of changes in phase boundaries and equation of state at this pressure. The transition can be interpreted as ferroelastic with the appearance of spontaneous strain that vanishes at the hydrogen bond symmetrization transition near 60 GPa.

Somayazulu,M.; Shu, J.; Zha, C.; Goncharov, A.; Tschauner, O.; Mao, H.; Hemley, R.

2008-01-01T23:59:59.000Z

113

Single-particle structure determination by correlations of snapshot X-ray diffraction patterns  

DOE Data Explorer (OSTI)

This deposition includes the diffraction images generated by the paired polystyrene spheres in random orientations. These images were used to determine and phase the single particle diffraction volume from their autocorrelation functions.

Starodub, D.

114

Structure determination of thin CoFe films by anomalous x-ray diffraction  

Science Conference Proceedings (OSTI)

This work reports on the investigation of structure-property relationships in thin CoFe films grown on MgO. Because of the very similar scattering factors of Fe and Co, it is not possible to distinguish the random A2 (W-type) structure from the ordered B2 (CsCl-type) structure with commonly used x-ray sources. Synchrotron radiation based anomalous x-ray diffraction overcomes this problem. It is shown that as grown thin films and 300 K post annealed films exhibit the A2 structure with a random distribution of Co and Fe. In contrast, films annealed at 400 K adopt the ordered B2 structure.

Gloskovskii, Andrei; Stryganyuk, Gregory; Ouardi, Siham [Institut fuer Anorganische und Analytische Chemie, Johannes Gutenberg-Universitaet, 55099 Mainz (Germany); Fecher, Gerhard H.; Felser, Claudia [Institut fuer Anorganische und Analytische Chemie, Johannes Gutenberg-Universitaet, 55099 Mainz (Germany); Max Planck Institute for Chemical Physics of Solids, D-01187 Dresden (Germany); Hamrle, Jaroslav; Pistora, Jaromir [Department of Physics and Nanotechnology Centre, VSB-Technical University of Ostrava, 70833 Ostrava (Czech Republic); Bosu, Subrojati; Saito, Kesami; Sakuraba, Yuya; Takanashi, Koki [Institute for Materials Research (IMR), Tohoku University, Sendai 980-8577 (Japan)

2012-10-01T23:59:59.000Z

115

The Coherent X-ray Imaging (CXI) Instrument at the Linac Coherent Light Source (LCLS)  

Science Conference Proceedings (OSTI)

The Linac Coherent Light Source (LCLS) has become the first ever operational hard X-ray Free Electron Laser in 2009. It will operate as a user facility capable of delivering unique research opportunities in multiple fields of science. The LCLS and the LCLS Ultrafast Science Instruments (LUSI) construction projects are developing instruments designed to make full use of the capabilities afforded by the LCLS beam. One such instrument is being designed to utilize the LCLS coherent beam to image with high resolution any sub-micron object. This instrument is called the Coherent X-ray Imaging (CXI) instrument. This instrument will provide a flexible optical system capable of tailoring key beam parameters for the users. A suite of shot-to-shot diagnostics will also be provided to characterize the beam on every pulse. The provided instrumentation will include multi-purpose sample environments, sample delivery and a custom detector capable of collecting 2D data at 120 Hz. In this article, the LCLS will be briefly introduced along with the technique of Coherent X-ray Diffractive Imaging (CXDI). A few examples of scientific opportunities using the CXI instrument will be described. Finally, the conceptual layout of the instrument will be presented along with a description of the key requirements for the overall system and specific devices required.

Boutet, Sebastien

2011-08-16T23:59:59.000Z

116

Fixture for supporting and aligning a sample to be analyzed in an x-ray diffraction apparatus  

DOE Patents (OSTI)

A fixture is provided for supporting and aligning small samples of material on a goniometer for x-ray diffraction analysis. A sample-containing capillary is accurately positioned for rotation in the x-ray beam by selectively adjusting the fixture to position the capillary relative to the x and y axes thereof to prevent wobble and position the sample along the z axis or the axis of rotation. By employing the subject fixture relatively small samples of materials can be analyzed in an x-ray diffraction apparatus previously limited to the analysis of much larger samples.

Green, L.A.; Heck, J.L. Jr.

1985-04-23T23:59:59.000Z

117

Optical and X-ray Imaging Techniques for Material Characterization ...  

Science Conference Proceedings (OSTI)

Ultrafast X-ray and 2-dimensional UV Spectroscopy of TiO2 Nanoparticles: Majed Chergui1; 1Ecole Polytechnique Fédérale de Lausanne Mesoporous titanium ...

118

Phase Sensitive X-ray Imager for More Accurate Digital ...  

Livermore Lab Report. News Archive. News ... use of higher energy X-rays which would result in a lower amount of absorbed radiation to the ... testing ...

119

Optical and X-ray Imaging Techniques for Material Characterization  

Science Conference Proceedings (OSTI)

Hyperspectral CARS Microscopy in the Fingerprint Region · In Situ X-ray ... Opportunities for Multimodal CARS Microscopy in Materials Science · Photoemission ...

120

Method and apparatus for molecular imaging using X-rays at resonance wavelengths  

DOE Patents (OSTI)

Holographic X-ray images are produced representing the molecular structure of a microscopic object, such as a living cell, by directing a beam of coherent X-rays upon the object to produce scattering of the X-rays by the object, producing interference on a recording medium between the scattered X-rays from the object and unscattered coherent X-rays and thereby producing holograms on the recording surface, and establishing the wavelength of the coherent X-rays to correspond with a molecular resonance of a constituent of such object and thereby greatly improving the contrast, sensitivity and resolution of the holograms as representations of molecular structures involving such constituent. For example, the coherent X-rays may be adjusted to the molecular resonant absorption line of nitrogen at about 401.3 eV to produce holographic images featuring molecular structures involving nitrogen.

Chapline, Jr., George F. (Alamo, CA)

1985-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "x-ray diffraction imaging" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


121

Using X-ray mammograms to assist in microwave breast image interpretation  

Science Conference Proceedings (OSTI)

Current clinical breast imaging modalities include ultrasound, magnetic resonance (MR) imaging, and the ubiquitous X-ray mammography. Microwave imaging, which takes advantage of differing electromagnetic properties to obtain image contrast, shows potential ...

Charlotte Curtis; Richard Frayne; Elise Fear

2012-01-01T23:59:59.000Z

122

A von Hamos x-ray spectrometer based on a segmented-type diffraction crystal for single-shot x-ray emission spectroscopy and time-resolved resonant inelastic x-ray scattering studies  

SciTech Connect

We report on the design and performance of a wavelength-dispersive type spectrometer based on the von Hamos geometry. The spectrometer is equipped with a segmented-type crystal for x-ray diffraction and provides an energy resolution in the order of 0.25 eV and 1 eV over an energy range of 8000 eV-9600 eV. The use of a segmented crystal results in a simple and straightforward crystal preparation that allows to preserve the spectrometer resolution and spectrometer efficiency. Application of the spectrometer for time-resolved resonant inelastic x-ray scattering and single-shot x-ray emission spectroscopy is demonstrated.

Szlachetko, J. [Paul Scherrer Institut, 5232 Villigen PSI (Switzerland); Institute of Physics, Jan Kochanowski University, 25-406 Kielce (Poland); Nachtegaal, M.; Boni, E. de; Willimann, M.; Safonova, O.; Sa, J.; Smolentsev, G.; Szlachetko, M.; Bergamaschi, A.; Schmitt, B.; David, C.; Luecke, A. [Paul Scherrer Institut, 5232 Villigen PSI (Switzerland); Bokhoven, J. A. van [Paul Scherrer Institut, 5232 Villigen PSI (Switzerland); Institute for Chemical and Bioengineering, ETH Zurich, 8093 Zuerich (Switzerland); Dousse, J.-Cl.; Hoszowska, J.; Kayser, Y. [Department of Physics, University of Fribourg, 1700 Fribourg (Switzerland); Jagodzinski, P. [University of Technology, Kielce (Poland)

2012-10-15T23:59:59.000Z

123

3D Visualization and interaction with spatiotemporal X-ray data to minimize radiation in image-guided surgery  

Science Conference Proceedings (OSTI)

Image-guided surgery (IGS) often depends on X-ray imaging, since pre-operative MRI, CT and PET scans do not provide an up-to-date internal patient view during the operation. X-rays introduce hazardous radiation, but long exposures for monitoring are ... Keywords: 3D cloud, 3D visualization, spatiotemporal X-ray data, radiation, image-guided surgery, X-ray imaging, prototype IGS system, motion tracking system, interactive visualization, 2D X-rays

F. Ioakeimidou; A. Olwal; A. Nordberg; H. von Holst

2011-06-01T23:59:59.000Z

124

Absolute x-ray energy calibration over a wide energy range using a diffraction-based iterative method  

SciTech Connect

In this paper, we report a method of precise and fast absolute x-ray energy calibration over a wide energy range using an iterative x-ray diffraction based method. Although accurate x-ray energy calibration is indispensable for x-ray energy-sensitive scattering and diffraction experiments, there is still a lack of effective methods to precisely calibrate energy over a wide range, especially when normal transmission monitoring is not an option and complicated micro-focusing optics are fixed in place. It is found that by using an iterative algorithm the x-ray energy is only tied to the relative offset of sample-to-detector distance, which can be readily varied with high precision of the order of 10{sup -5}-10{sup -6} spatial resolution using gauge blocks. Even starting with arbitrary initial values of 0.1 A, 0.3 A, and 0.4 A, the iteration process converges to a value within 3.5 eV for 31.122 keV x-rays after three iterations. Different common diffraction standards CeO{sub 2}, Au, and Si show an energy deviation of 14 eV. As an application, the proposed method has been applied to determine the energy-sensitive first sharp diffraction peak of network forming GeO{sub 2} glass at high pressure, exhibiting a distinct behavior in the pressure range of 2-4 GPa. Another application presented is pair distribution function measurement using calibrated high-energy x-rays at 82.273 keV. Unlike the traditional x-ray absorption-based calibration method, the proposed approach does not rely on any edges of specific elements, and is applicable to the hard x-ray region where no appropriate absorption edge is available.

Hong Xinguo; Chen Zhiqiang [Mineral Physics Institute, Stony Brook University, Stony Brook, New York 11794 (United States); Duffy, Thomas S. [Department of Geosciences, Princeton University, Princeton, New Jersey 08544 (United States)

2012-06-15T23:59:59.000Z

125

Dynamic in-situ X-ray Diffraction of Catalyzed Alanates  

DOE Green Energy (OSTI)

The discovery that hydrogen can be reversible absorbed and desorbed from NaAlH{sub 4} by the addition of catalysts has created an entirely new prospect for lightweight hydrogen storage. NaAlH{sub 4} releases hydrogen through the following set of decomposition reactions: NaAlH{sub 4} {r_arrow} 1/3({alpha}-Na{sub 3}AlH{sub 6}) + 2/3Al + H{sub 2} {r_arrow} NaH + Al + 3/2H{sub 2}. These decomposition reactions as well as the reverse recombination reactions were directly observed using time-resolved in-situ x-ray powder diffraction. These measurements were performed under conditions similar to those found in PEM fuel cell operations (hydrogen absorption: 50--70 C, 10--15 bar Hz, hydrogen resorption: 80--110 C, 5--100 mbar H{sub 2}). Catalyst doping was found to dramatically improve kinetics under these conditions. In this study, the alanate was doped with a catalyst by dry ball-milling NaAlH{sub 4} with 2 mol.% solid TiCl{sub 3}. X-ray diffraction clearly showed that TiCl{sub 3} reacts with NaAlH{sub 4} to form NaCl during the doping process. Partial desorption of NaAlH{sub 4} was even observed to occur during the catalyst doping process.

Gross, K.J.; Sandrock, G.; Thomas, G.J.

2000-11-01T23:59:59.000Z

126

Lensless Imaging of Magnetic Nanostructures by X-ray Spectro...  

NLE Websites -- All DOE Office Websites (Extended Search)

F. Schlotter and J. Sthr (SSRL) The unprecedented properties of X-ray free electron lasers (X-FELs) under development world wide will open the door for entirely new classes of...

127

Directional x-ray dark-field imaging of strongly ordered systems  

Science Conference Proceedings (OSTI)

Recently a novel grating based x-ray imaging approach called directional x-ray dark-field imaging was introduced. Directional x-ray dark-field imaging yields information about the local texture of structures smaller than the pixel size of the imaging system. In this work we extend the theoretical description and data processing schemes for directional dark-field imaging to strongly scattering systems, which could not be described previously. We develop a simple scattering model to account for these recent observations and subsequently demonstrate the model using experimental data. The experimental data includes directional dark-field images of polypropylene fibers and a human tooth slice.

Jensen, Torben Haugaard; Feidenhans'l, Robert [Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen (Denmark); Bech, Martin; Pfeiffer, Franz [Department of Physics, Technical University of Munich, 85747 Garching (Germany); Zanette, Irene; Weitkamp, Timm [European Synchrotron Radiation Facility, 38043 Grenoble (France); David, Christian; Rutishauser, Simon [Paul Scherrer Institut, 5232 Villigen PSI (Switzerland); Deyhle, Hans [Biomaterials Science Center, University of Basel, 4031 Basel (Switzerland); Institute for Materials Science, School of Dental Medicine, University of Basel, 4031 Basel (Switzerland); Reznikova, Elena; Mohr, Juergen [Karlsruhe Institute of Technology, Institute for Microstructure Technology, 76021 Karlsruhe (Germany)

2010-12-01T23:59:59.000Z

128

Apparatus for obtaining an X-ray image  

DOE Patents (OSTI)

A computed tomography apparatus in which a fan-shaped X-ray beam is caused to pass through a section of an object, enabling absorption detection on the opposite side of the object by a detector comprising a plurality of discrete detector elements. An electron beam generating the X-ray beam by impacting upon a target is caused to rotate over the target.

Watanabe, Eiji (Tokyo, JP)

1979-01-01T23:59:59.000Z

129

Influence of diffraction in crystals on the coherence properties of X-ray free-electron laser pulses  

SciTech Connect

The spatial and temporal evolution of the field of random X-ray femtosecond pulses and their coherent properties upon pulse propagation in free space and under dynamical diffraction in perfect crystals in the Bragg and Laue geometries has been analyzed on the basis of the formalism developed in statistical optics. Particular attention is paid to the influence of large pulse propagation distances, which are characteristic of lengthy channels of X-ray free-electron lasers.

Bushuev, V. A., E-mail: vabushuev@yandex.ru [Moscow State University (Russian Federation); Samoylova, L. [European XFEL GmbH (Germany)

2011-09-15T23:59:59.000Z

130

Magnetic soft x-ray microscopy-imaging fast spin dynamics inmagnetic nanostructures  

SciTech Connect

Magnetic soft X-ray microscopy combines 15nm spatial resolution with 70ps time resolution and elemental sensitivity. Fresnel zone plates are used as X-ray optics and X-ray magnetic circular dichroism serves as magnetic contrast mechanism. Thus scientifically interesting and technologically relevant low dimensional nanomagnetic systems can be imaged at fundamental length and ultrafast time scales in a unique way. Studies include magnetization reversal in magnetic multilayers, nanopatterned systems, vortex dynamics in nanoelements and spin current induced phenomena.

Fischer, Peter; Kim, Dong-Hyun; Mesler, Brooke L.; Chao, Weilun; Sakdinawat, Anne E.; Anderson, Erik H.

2007-06-01T23:59:59.000Z

131

ZnTe:O phosphor development for x-ray imaging applications  

Science Conference Proceedings (OSTI)

An efficient ZnTe:O x-ray powder phosphor was prepared by a dry synthesis process using gaseous doping and etching medias. The x-ray luminescent properties were evaluated and compared to standard commercial phosphors exhibited an x-ray luminescent efficiency equivalent to 76% of Gd{sub 2}O{sub 2}S:Tb and an equal resolution of 2.5 lines/mm. In addition, the fast decay time, low afterglow, and superior spectral match to conventional charge-coupled devices-indicate that ZnTe:O is a very promising phosphor candidate for x-ray imaging applications.

Kang, Z.T.; Summers, C.J.; Menkara, H.; Wagner, B.K.; Durst, R.; Diawara, Y.; Mednikova, G.; Thorson, T. [Phosphor Technology Center of Excellence, School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332-0245 (United States); Georgia Tech Research Institute, Georgia Institute of Technology, Atlanta, Georgia 30332-0826 (United States); Bruker AXS 5465 East Cheryl Parkway, Madison Wisconson 53711 (United States)

2006-03-13T23:59:59.000Z

132

X-ray Image Bank Open for Business - NERSC Center News, Feb 22...  

NLE Websites -- All DOE Office Websites (Extended Search)

X-ray Image Bank Open for Business February 22, 2011 Filipe Maia is building a data bank where scientists from around the world can deposit and share images generated by...

133

Characterization of nanocrystalline Pd by x-ray diffraction and EXAFS  

DOE Green Energy (OSTI)

Since the fraction of atoms located within a few atomic distances of one or more internal interfaces increases rapidly with decreasing grain size in the nanometer regime, it is expected that the structure of grain boundaries plays an important role in determining and controlling the properties of nanocrystalline materials. A high resolution electron microscopy study of nanocrystalline Pd found no evidence for extended, disordered boundary regions that would differ from boundaries in coarse-grained materials. Recent results from x-ray diffraction, EXAFS and hydriding studies have yielded clear evidence that the boundaries in nanocrystalline Pd are ordered and/or extremely localized in nature. The present paper will summarize and discuss the principal results of these three studies. 12 refs., 4 figs.

Eastman, J.A. (Argonne National Lab., IL (USA)); Fitzsimmons, M.R.; Mueller-Stach, M.; Wallner, G. (Ludwig-Maximilians-Universitaet, Munich (Germany, F.R.)); Elam, W.T. (Naval Research Lab., Washington, DC (USA))

1990-12-01T23:59:59.000Z

134

Kinetics of Methane Hydrate Decomposition Studied via in Situ Low Temperature X-ray Powder Diffraction  

SciTech Connect

Gas hydrates are known to have a slowed decomposition rate at ambient pressure and temperatures below the melting point of ice termed self-preservation or anomalous preservation. As hydrate exothermically decomposes, gas is released and water of the clathrate cages transforms into ice. Two regions of slowed decomposition for methane hydrate, 180 200 K and 230 260 K, were observed, and the kinetics were studied by in situ low temperature x-ray powder diffraction. The kinetic constants for ice formation from methane hydrate were determined by the Avrami model within each region and activation energies, Ea, were determined by the Arrhenius plot. Ea determined from the data for 180 200 K was 42 kJ/mol and for 230 260 K was 22 kJ/mol. The higher Ea in the colder temperature range was attributed to a difference in the microstructure of ice between the two regions.

Everett, Susan M [ORNL; Rawn, Claudia J [ORNL; Keffer, David J. [University of Tennessee, Knoxville (UTK); Mull, Derek L [ORNL; Payzant, E Andrew [ORNL; Phelps, Tommy Joe [ORNL

2013-01-01T23:59:59.000Z

135

High-Resolution X-ray Imaging of the Colliding Wind Shock in WR147  

E-Print Network (OSTI)

We analyze new high-resolution Chandra X-ray images of the Wolf-Rayet binary system WR147. This system contains a WN8 star with an early-type companion located 0.6'' to its north, and is the only known early-type binary with a separation on the sky large enough for the wind-wind collision between the stars to currently be resolved at X-ray energies. The 5 ksec Chandra HRC-I image provides the first direct evidence for spatially extended X-ray emission in an early-type binary system. The X-ray emission peaks close to the position of the radio bow shock and north of the WN8 star. A deeper X-ray image is needed to accurately determine the degree of spatial extension, to exactly align the X-ray and optical/radio frames, and to determine whether part of the detected X-ray emission arises in the individual stellar winds. Simulated X-ray images of the wind-wind collision have a FWHM consistent with the data, and maximum likelihood fits suggest that a deeper observation may also constrain the inclination and wind momentum ratio of this system. However, as the WR wind dominates the colliding wind X-ray emission it appears unlikely that the mass-loss rate and the terminal velocity of the companion wind can be separately determined from X-ray observations. We also note an inconsistency between numerical and analytical estimates of the X-ray luminosity ratio of the stronger and weaker wind components, and conclude that the analytical results are in error.

J. M. Pittard; I. R. Stevens; P. M. Williams; A. M. T. Pollock; S. L. Skinner; M. F. Corcoran; A. F. J. Moffat

2002-04-12T23:59:59.000Z

136

High-energy x-ray backlighter spectrum measurements using calibrated image plates  

Science Conference Proceedings (OSTI)

The x-ray spectrum between 18 and 88 keV generated by a petawatt laser driven x-ray backlighter target was measured using a 12-channel differential filter pair spectrometer. The spectrometer consists of a series of filter pairs on a Ta mask coupled with an x-ray sensitive image plate. A calibration of Fuji{trademark} MS and SR image plates was conducted using a tungsten anode x-ray source and the resulting calibration applied to the design of the Ross pair spectrometer. Additionally, the fade rate and resolution of the image plate system were measured for quantitative radiographic applications. The conversion efficiency of laser energy into silver K{alpha} x rays from a petawatt laser target was measured using the differential filter pair spectrometer and compared to measurements using a single photon counting charge coupled device.

Maddox, B.R.; Park, H.S.; Remington, B.A.; Izumi, N.; Chen, S.; Chen, C.; Kimminau, G.; Ali, Z.; Haugh, M.J.; Ma, Q. (LLNL); (NWU); (Oxford); (NSTec)

2012-10-10T23:59:59.000Z

137

High-energy x-ray backlighter spectrum measurements using calibrated image plates  

Science Conference Proceedings (OSTI)

The x-ray spectrum between 18 and 88 keV generated by a petawatt laser driven x-ray backlighter target was measured using a 12-channel differential filter pair spectrometer. The spectrometer consists of a series of filter pairs on a Ta mask coupled with an x-ray sensitive image plate. A calibration of Fuji MS and SR image plates was conducted using a tungsten anode x-ray source and the resulting calibration applied to the design of the Ross pair spectrometer. Additionally, the fade rate and resolution of the image plate system were measured for quantitative radiographic applications. The conversion efficiency of laser energy into silver K{alpha} x rays from a petawatt laser target was measured using the differential filter pair spectrometer and compared to measurements using a single photon counting charge coupled device.

Maddox, B. R.; Park, H. S.; Remington, B. A.; Izumi, N.; Chen, S.; Chen, C. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Kimminau, G. [Department of Physics, Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU (United Kingdom); Ali, Z.; Haugh, M. J. [National Security Technologies, LLC, Livermore, California 94550 (United States); Ma, Q. [DND-CAT, Argonne National Laboratory, Argonne, Illinois 60439-4857 (United States)

2011-02-15T23:59:59.000Z

138

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

SciTech Connect

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

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

2012-02-15T23:59:59.000Z

139

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

Science Conference Proceedings (OSTI)

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

Stoupin, S.; Shvydko, Y.; Shu, D.; Khachatryan, R.; Xiao, X. (X-Ray Science Division)

2012-01-01T23:59:59.000Z

140

Fresnel zone plates for Achromatic Imaging Survey of X-ray sources  

SciTech Connect

A telescope with Fresnel Zone Plates has been contemplated to be an excellent imaging mask in X-rays and gamma-rays for quite some time. With a proper choice of zone plate material, spacing and an appropriate readout system it is possible to achieve any theoretical angular resolution. We provide the results of numerical simulations of how a large number of X-ray sources could be imaged at a high resolution. We believe that such an imager would be an excellent tool for a future survey mission for X-ray and gamma-ray sources which we propose.

Palit, Sourav [Indian Centre for Space Physics (ICSP), Chalantika 43, Garia Station Rd., Kolkata, 700084 (India); Chakrabarti, S. K. [S. N. Bose National Center for Basic Sciences, JD-Block, Salt Lake, Kolkata, 700098 (India); Debnath, D. [Indian Centre for Space Physics (ICSP), Chalantika 43, Garia Station Road Kolkata 700084 (India); Yadav, Vipin; Nandi, Anuj [Indian Centre for Space Physics (ICSP), Chalantika 43, Garia Station Road Kolkata 700084 (India); On deputation from Indian Space Research Organization HQ, Bangalore 560 231 (India)

2008-10-08T23:59:59.000Z

Note: This page contains sample records for the topic "x-ray diffraction imaging" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


141

Imaging nanoscale magnetic structures with polarized soft x-ray photons  

SciTech Connect

Imaging nanoscale magnetic structures and their fast dynamics is scientifically interesting and technologically of highest relevance. The combination of circularly polarized soft X-ray photons which provide a strong X-ray magnetic circular dichroism effect at characteristic X-ray absorption edges, with a high resolution soft X-ray microscope utilizing Fresnel zone plate optics allows to study in a unique way the stochastical behavior in the magnetization reversal process of thin films and the ultrafast dynamics of magnetic vortices and domain walls in confined ferromagnetic structures. Future sources of fsec short and high intense soft X-ray photon pulses hold the promise of magnetic imaging down to fundamental magnetic length and time scales.

Fischer, P.; Im, M.-Y.

2010-01-18T23:59:59.000Z

142

CALIBRATION OF X-RAY IMAGING DEVICES FOR ACCURATE INTENSITY MEASUREMENT  

SciTech Connect

National Security Technologies (NSTec) has developed calibration procedures for X-ray imaging systems. The X-ray sources that are used for calibration are both diode type and diode/fluorescer combinations. Calibrating the X-ray detectors is key to accurate calibration of the X-ray sources. Both energy dispersive detectors and photodiodes measuring total flux were used. We have developed calibration techniques for the detectors using radioactive sources that are traceable to the National Institute of Standards and Technology (NIST). The German synchrotron at Physikalische Technische Bundestalt (PTB) is used to calibrate silicon photodiodes over the energy range from 50 eV to 60 keV. The measurements on X-ray cameras made using the NSTec X-ray sources have included quantum efficiency averaged over all pixels, camera counts per photon per pixel, and response variation across the sensor. The instrumentation required to accomplish the calibrations is described. X-ray energies ranged from 720 eV to 22.7 keV. The X-ray sources produce narrow energy bands, allowing us to determine the properties as a function of X-ray energy. The calibrations were done for several types of imaging devices. There were back illuminated and front illuminated CCD (charge coupled device) sensors, and a CID (charge injection device) type camera. The CCD and CID camera types differ significantly in some of their properties that affect the accuracy of X-ray intensity measurements. All cameras discussed here are silicon based. The measurements of quantum efficiency variation with X-ray energy are compared to models for the sensor structure. Cameras that are not back-thinned are compared to those that are.

Haugh, M J; Charest, M R; Ross, P W; Lee, J J; Schneider, M B; Palmer, N E; Teruya, A T

2012-02-16T23:59:59.000Z

143

Dual microchannel plate module for a gated monochromatic x-ray imager  

SciTech Connect

Development and testing of a dual microchannel plate (MCP) module to be used in the national Inertial Confinement Fusion (ICF) program has recently been completed. The MCP module is a key component of a new monochromatic x-ray imaging diagnostic which is designed around a 4 channel Kirkpatrick-Baez microscope and diffraction crystals which is located at University of Rochester`s Omega laser system. The MCP module has two separate MCP regions with centers spaced 53 mm apart. Each region contains a 25 mm MCP proximity focused to a P-11 phosphor coated fiberoptic faceplate. The two L/D = 40, MCPs have a 10.2 mm wide, 8 ohm stripline constructed of 500 nm Copper overcoated with 100 nm Gold. A 4 kV, 150 ps electrical pulse provides an optical gatewidth of 80 ps and spatial resolution has been measured at 20 1p/mm.

Oertel, J.A.; Archuleta, T.; Peterson, C.G. [and others

1996-06-01T23:59:59.000Z

144

X-ray Imaging of Shock Waves Generated by High-Pressure Fuel...  

NLE Websites -- All DOE Office Websites (Extended Search)

X-ray Imaging of Shock Waves Generated by High-Pressure Fuel Sprays High-pressure, high-speed fuel sprays are a critical technology for many applications including fuel injection...

145

Three Dimensional X-Ray Scanning Micro/Nano-Diffraction Probe ...  

Science Conference Proceedings (OSTI)

... Magnetic Composite Materials · X-Ray Studies of Structural Effects Induced by Pulsed (30 Tesla), High Magnetic Fields at the Advanced Photon Source ...

146

Amorphisation mechanism of a flint aggregate during the alkali-silica reaction: X-ray diffraction and X-ray absorption XANES contributions  

Science Conference Proceedings (OSTI)

Flint samples at different stages of the Alkali-Silica Reaction were prepared and analyzed by X-ray diffraction (XRD) and silicon K-edge X-ray absorption near edge structure techniques (XANES). The results are compared to those of measurements performed on alpha quartz c-SiO{sub 2} and rough flint aggregate. The molar fraction of Q{sub 3} sites is determined as a function of the time of reaction. Up to 14 h of attack, the effect of the reaction seems of little importance. From 30 to 168 h, we showed an acceleration of the effect of the reaction on the crystal structure of the aggregate resulting in an amorphisation of the crystal. During this period, the amorphous fraction increases linearly with the number of Q{sub 3} sites. The results of the XANES confirm the amorphisation of the aggregate during the reaction and show the presence of silicon in a tetrahedral environment of oxygen whatever the time of attack.

Verstraete, J.; Khouchaf, L.; Bulteel, D.; Garcia-Diaz, E.; Flank, A.M; Tuilier, M.H

2004-04-01T23:59:59.000Z

147

3D View Inside the Skeleton with X-ray Microscopy: Imaging Bone at the  

NLE Websites -- All DOE Office Websites (Extended Search)

3D View Inside the Skeleton with X-ray Microscopy: Imaging Bone 3D View Inside the Skeleton with X-ray Microscopy: Imaging Bone at the Nanoscale Scientists studying osteoporosis and other skeletal diseases are interested in the 3D structure of bone and its responses to conditions such as weightlessness, radiation (of particular interest to astronauts) and vitamin D deficiency. The current gold standard, micro-computed tomography (micro-CT), provides 3D images of trabeculae, the small interior struts of bone tissue, and electron microscopy can provide nanometer resolution of thin tissue slices. Hard X-ray transmission microscopy has provided the first 3D view of bone structure within individual trabeculae on the nanoscale. figure 1 Figure 1 Micro-CT (left) shows trabecular structure inside of bone. Transmission X-ray microscopy (TXM; center and right) can reveal localized details of osteocyte lacunae and their processes.

148

X-ray tomographic image magnification process, system and apparatus therefor  

DOE Patents (OSTI)

A computerized three-dimensional x-ray tomographic microscopy system is disclosed, comprising: (a) source means for providing a source of parallel x-ray beams; (b) staging means for staging and sequentially rotating a sample to be positioned in the path of the beams; (c) x-ray image magnifier means positioned in the path of the beams downstream from the sample; (d) detecting means for detecting the beams after being passed through and magnified by the image magnifier means; and (e) computing means for analyzing values received from the detecting means, and converting the values into three-dimensional representations. Also disclosed is a process for magnifying an x-ray image, and apparatus therefor.

Kinney, J.H.; Bonse, U.K.; Johnson, Q.C.; Nichols, M.C.; Saroyan, R.A.; Massey, W.N.; NuBhardt, R.

1991-12-31T23:59:59.000Z

149

Kinetic Analysis of Cation Exchange in Birnessite using Time-resolved Synchrotron X-ray Diffraction  

SciTech Connect

In this study, we applied time-resolved synchrotron X-ray diffraction (TRXRD) to develop kinetic models that test a proposed two-stage reaction pathway for cation exchange in birnessite. These represent the first rate equations calculated for cation exchange in layered manganates. Our previous work has shown that the substitution of K, Cs, and Ba for interlayer Na in synthetic triclinic birnessite induces measurable changes in unit-cell parameters. New kinetic modeling of this crystallographic data supports our previously postulated two-stage reaction pathway for cation exchange, and we can correlate the kinetic steps with changes in crystal structure. In addition, the initial rates of cation exchange, R ({angstrom}{sup 3} min{sup -1}), were determined from changes in unit-cell volume to follow these rate laws: R = 1.75[K{sup +}{sub (aq)}]{sup 0.56}, R = 41.1[Cs{sup +}{sub (aq)}]{sup 1.10}, R = 1.15[Ba{sup 2+}{sub (aq)}]{sup 0.50}. Thus, the exchange rates for Na in triclinic birnessite decreased in the order: Cs >> K > Ba. These results are likely a function of hydration energy differences of the cations and the preference of the solution phase for the more readily hydrated cation.

C Lopano; P Heaney; J Bandstra; J Post; S Brantley

2011-12-31T23:59:59.000Z

150

An experimental apparatus for diffraction-limites soft x-ray nanofocusing  

Science Conference Proceedings (OSTI)

Realizing the experimental potential of high-brightness, next generation synchrotron and free-electron laser light sources requires the development of reflecting x-ray optics capable of wavefront preservation and high-resolution nano-focusing. At the Advanced Light Source (ALS) beamline 5.3.1, we are developing broadly applicable, high-accuracy, in situ, at-wavelength wavefront measurement techniques to surpass 100-nrad slope measurement accuracy for diffraction-limited Kirkpatrick-Baez (KB) mirrors. The at-wavelength methodology we are developing relies on a series of wavefront-sensing tests with increasing accuracy and sensitivity, including scanning-slit Hartmann tests, grating-based lateral shearing interferometry, and quantitative knife-edge testing. We describe the original experimental techniques and alignment methodology that have enabled us to optimally set a bendable KB mirror to achieve a focused, FWHM spot size of 150 nm, with 1 nm (1.24 keV) photons at 3.7 mrad numerical aperture. The predictions of wavefront measurement are confirmed by the knife-edge testing.The side-profiled elliptically bent mirror used in these one-dimensional focusing experiments was originally designed for a much different glancing angle and conjugate distances. This work demonstrates that high-accuracy, at-wavelength wavefront-slope feedback can be used to optimize the pitch, roll, and mirror-bending forces in situ, using procedures that are deterministic and repeatable.

Merthe, Daniel; Goldberg, Kenneth; Yashchuk, Valeriy; Yuan, Sheng; McKinney, Wayne; Celestre, Richard; Mochi, Iacopo; Macdougall, James; Morrison, Gregory; Rakawa, Senajith; Anderson, Erik; Smith, Brian; Domning, Edward; Warwick, Tony; Padmore, Howard

2011-10-21T23:59:59.000Z

151

Thin, X-ray-Transparent Windows for Imaging Applications with a Pneumatically Pressurized Enclosure  

SciTech Connect

We have developed a novel thin, x-ray-transparent window system for environmental chambers involving pneumatic pressures above 10 bar. The windows allow for x-ray access to fuel sprays injected into a pressurized chamber that mimics realistic internal combustion engine cylinder operating conditions. The design of the window system and its experimental test results are presented in this paper, as well as its further development for in situ x-ray imaging applications in a high-pressure and high-temperature environment.

Shu Deming; Wang Jin; Preissner, Curt [Advanced Photon Source, Argonne National Laboratory, Argonne, IL 60439 (United States)

2007-01-19T23:59:59.000Z

152

Imaging of lateral spin valves with soft x-ray microscopy  

SciTech Connect

We investigated Co/Cu lateral spin valves by means of high-resolution transmission soft x-ray microscopy with magnetic contrast that utilizes x-ray magnetic circular dichroism (XMCD). No magnetic XMCD contrast was observed at the Cu L{sub 3} absorption edge, which should directly image the spin accumulation in Cu. Although electrical transport measurements in a non-local geometry clearly detected the spin accumulation in Cu, which remained unchanged during illumination with circular polarized x-rays at the Co and Cu L{sub 3} absorption edges.

Mosendz, O.; Mihajlovic, G.; Pearson, J. E.; Fischer, P.; Im, M.-Y.; Bader, S. D.; Hoffmann, A.

2009-05-01T23:59:59.000Z

153

Edge-enhanced imaging obtained with very broad energy band x-rays  

SciTech Connect

We demonstrate both theoretically and experimentally that edge-enhancement effects are produced when objects, in contact with the x-ray detector, are imaged by using very broad x-ray spectra. Radiographs of thin Al objects have been obtained with a table-top synchrotron source which generates x-rays in the energy range from a few kilo-electron-volts up to 6 MeV. Edge-enhancement effects arise from the combination of x-ray absorption (kilo-electron-volt part of the spectrum) and secondary particle emission (mega-electron-volt part of the spectrum) within the sample. The exact contribution of absorption and emission profiles in the edge-enhanced images has been calculated via Monte Carlo simulation.

Taibi, A.; Cardarelli, P.; Di Domenico, G.; Marziani, M.; Gambaccini, M. [Department of Physics, University of Ferrara, INFN Section of Ferrara, via Saragat 1, 44100 Ferrara (Italy); Hanashima, T. [Photon Production Laboratory Ltd., 1-1-1 Nojihigashi, Kusatsu, Shiga 525-8577 (Japan); Yamada, H. [Synchrotron Light Life Science Center, Ritsumeikan University, 1-1-1 Nojihigashi, Kusatsu, Shiga 525-8577 (Japan)

2010-04-05T23:59:59.000Z

154

Image plates as x-ray detectors in plasma physics experiments  

SciTech Connect

The performance of image plates based on the photostimulable phosphor BaF(Br,l):Eu{sup 2+} has been investigated and compared with x-ray film. Evaluation of detective quantum efficiency (DQE), sensitivity, dynamic range, and linearity was carried out for several types of commercially available image plate, using the Excalibur soft x-ray calibration facility at AWE. Image plate response was found to be linear over a dynamic range of 5 orders of magnitude. One type of image plate was found to have a number of advantages for soft x-ray detection, with a measured sensitivity 1 order of magnitude greater than that of Kodak Industrex CX and DEF-5 x-ray film. The DQE of this plate was found to be superior to that of film at low [less than 10{sup 3} photons/(50 {mu}m){sup 2}] and high fluxes [greater than 10{sup 4} photons/(50 {mu}m){sup 2}]. The spatial resolution of image plates, scanned with several models of commercial image plate readers, has been evaluated using a USAF resolution test target. The highest spatial resolution measured is 35 {mu}m. Though this is significantly lower than the resolution possible with film, it is sufficient for many applications. Image plates were fielded in a refractive x-ray lens imaging diagnostic on the 1 TW Helen laser and these results are discussed.

Gales, S.G.; Bentley, C.D. [AWE Aldermaston, Reading RG7 4PR (United Kingdom)

2004-10-01T23:59:59.000Z

155

Application of X-ray Refraction-Contrast to Medical Joint Imaging  

Science Conference Proceedings (OSTI)

The refraction-contrast X-ray imaging technique using synchrotron X-ray has been applied to an 8 mm sliced distal end of a human femur involving ligament and articular cartilage at 15 keV. It was shown that this technique can clearly depict the fine structures of the ligament, its torn surface and substantial articular cartilage at near the just Bragg angular position. The entrance surface dose necessary for each image was approximately 4 mGy by using an imaging plate. This imaging technique may become a powerful tool for depicting abnormalities of the ligament and articular cartilage.

Shimao, Daisuke [Department of Material Structural Sciences, School of Mathematical and Physical Science, Graduate University for Advanced Studies, Oho 1-1, Tsukuba, Ibaraki 305-0801 (Japan); Mori, Koichi [Department of Radiological Sciences, Ibaraki Prefectural University of Health Sciences, Ami 4669-2, Inashiki, Ibaraki 300-0394 (Japan); Hyodo, Kazuyuki [Photon Factory, Institute of Materials Structure Sciences, High Energy Accelerator Research Organization, Oho 1-1, Tsukuba, Ibaraki 305-0801 (Japan); Sugiyama, Hiroshi [Department of Material Structural Sciences, School of Mathematical and Physical Science, Graduate University for Advanced Studies, Oho 1-1, Tsukuba, Ibaraki 305-0801 (Japan); Department of Photo-Science, School of Advanced Studies, Graduate University for advanced studies, International Village, Hayama, Kanagawa 240-0193 (Japan); Ando, Masami [Department of Material Structural Sciences, School of Mathematical and Physical Science, Graduate University for Advanced Studies, Oho 1-1, Tsukuba, Ibaraki 305-0801 (Japan); Photon Factory, Institute of Materials Structure Sciences, High Energy Accelerator Research Organization, Oho 1-1, Tsukuba, Ibaraki 305-0801 (Japan); Department of Photo-Science, School of Advanced Studies, Graduate University for advanced studies, International Village, Hayama, Kanagawa 240-0193 (Japan)

2004-05-12T23:59:59.000Z

156

Scanner for integrated x-ray breast tomosynthesis and molecular breast imaging tomosynthesis  

Science Conference Proceedings (OSTI)

A dual modality tomosynthesis (DMT) breast scanner has been developed that combines x-ray breast tomosynthesis (XBT) and molecular breast imaging tomosynthesis (MBIT) on a common upright gantry to obtain co-registered structural and functional tomosynthesis ... Keywords: breast tomosynthesis, hybrid scanners, limited angle SPECT, molecular breast imaging, multimodality imaging

Mark B. Williams; Patricia G. Judy; Zongyi Gong; Audrey E. Graham; Stan Majewski; Spencer Gunn

2010-06-01T23:59:59.000Z

157

High-Energy Synchrotron X-Ray Diffraction for In-Situ Study of ...  

Science Conference Proceedings (OSTI)

At the APS high-energy x-ray beamline 11-ID-C, we have employed 115 keV ... ( Use of the Advanced Photon Source was supported by the U. S. Department of ...

158

Ruthenium-Platinum Thin Film Analysis Using Grazing Incidence X-ray Diffraction  

DOE Green Energy (OSTI)

Ruthenium (Ru, Z = 44) is a Platinum Group Metal that has a standard hexagonal close packed (HCP) crystalline structure. Platinum (Pt, Z = 78) has a face-centered cubic (FCC) crystalline structure. When these metals are co-sputtered onto a silicon substrate, creating a few nm-thin film, they form an alloy with a combination of HCP and FCC structure. Direct methanol fuel cells rely on an anode catalyst to draw hydrogen from liquid methanol. Highly efficient fuel cells based on polymer electrolyte catalysts, known as proton-exchange membrane fuel cells, have been developed, but require large amounts of a costly platinum catalyst. Thin-film nanostructure bimetallic alloys have been produced to reduce the amount of expensive Platinum needed for catalysis, and also to improve the electrochemical properties of the catalyst. Supported RuPt particles have been shown to have superior activity as anode catalysts for methanol electro-oxidation and demonstrate an improvement in resistance to poisoning in comparison to unalloyed Pt. The percentage of Ruthenium in a RuPt thin film and the process by which the alloy is produced will dictate the crystalline structure, and thus the electrochemical properties of the film. Pure Ruthenium, Pure Platinum, and eight intermediate samples at differing percent composition of Ruthenium were characterized by their X-ray diffraction patterns. The incident beam is from the Stanford Synchrotron Radiation Laboratory beam and operates at approximately a 1.4 Angstrom wavelength. The results show that 0% Ru through 46.17% Ru exhibit a majority FCC structure, 56.07% Ru and 60.61% Ru are mixed phase, and from 67.03% Ru through 100% Ru, the samples exhibit a HCP structure.

Jones, L.

2004-09-03T23:59:59.000Z

159

SCANNING ELECTRON MICROSCOPY AND X-RAY DIFFRACTION ANALYSIS OF TANK 18 SAMPLES  

Science Conference Proceedings (OSTI)

The F-Area Tank Farm (FTF) Performance Assessment (PA) utilizes waste speciation in the waste release model used in the FTF fate and transport modeling. The waste release modeling associated with the residual plutonium in Tank 18 has been identified as a primary contributor to the Tank 18 dose uncertainty. In order to reduce the uncertainty related to plutonium in Tank 18, a better understanding of the plutonium speciation in the Tank 18 waste (including the oxidation state and stoichiometry) is desired. Savannah River National Laboratory (SRNL) utilized Scanning Electron Microscopy (SEM) and X-ray Diffraction (XRD) to analyze Tank 18 samples to provide information on the speciation of plutonium in the waste material. XRD analysis of the Tank 18 samples did not identify any plutonium mineral phases in the samples. These indicates the crystalline mineral phases of plutonium are below the detection limits of the XRD method or that the plutonium phase(s) lack long range order and are present as amorphous or microcrystalline solids. SEM analysis of the Tank 18 samples did locate particles containing plutonium. The plutonium was found as small particles, usually <1 {micro}m but ranging up to several micrometers in diameter, associated with particles of an iron matrix and at low concentration in other elemental matrices. This suggests the plutonium has an affinity for the iron matrix. Qualitatively, the particles of plutonium found in the SEM analysis do not appear to account for all of the plutonium in the sample based on concentrations determined from the chemical analysis of the Tank 18 samples. This suggests that plutonium is also distributed throughout the solids in low concentrations.

Hay, M.; O'Rourke, P.; Ajo, H.

2012-03-08T23:59:59.000Z

160

Cu isotope fractionation during bornite dissolution: An in situ X-ray diffraction analysis  

Science Conference Proceedings (OSTI)

Low-temperature ore deposits exhibit a large variation in {delta}{sup 65}Cu ({approx}12{per_thousand}), and this range has been attributed, in part, to isotope fractionation during weathering reactions of primary minerals such as chalcocite and chalcopyrite. Here, we examine the fractionation of Cu isotopes during dissolution of another important Cu ore mineral, bornite, using a novel approach that combines time-resolved X-ray diffraction (XRD) and isotope analysis of reaction products. During the initial stages of bornite oxidative dissolution by ferric sulfate ( 20 mol% Cu was leached from the solid, the difference between the Cu isotope composition of the aqueous and mineral phases approached zero, with {Delta}{sub aq - min}{sup 0} values ranging from - 0.21 {+-} 0.61{per_thousand} to 0.92 {+-} 0.25{per_thousand}. XRD analysis allowed us to correlate changes in the atomic structure of bornite with the apparent isotope fractionation as the dissolution reaction progressed. These data revealed that the greatest degree of apparent fractionation is accompanied by a steep contraction in the unit-cell volume, which we identified as a transition from stoichiometric to non-stoichiometric bornite. We propose that the initially high {Delta}{sub aq - min} values result from isotopically heavy Cu ({sup 65}Cu) concentrating within Cu{sup 2+} during dissolution. The decrease in the apparent isotope fractionation as the reaction progresses occurs from the distillation of isotopically heavy Cu ({sup 65}Cu) during dissolution or kinetic isotope effects associated with the depletion of Cu from the surfaces of bornite particles.

Wall, Andrew J.; Mathur, Ryan; Post, Jeffrey E.; Heaney, Peter J. (Juniata); (Smithsonian); (Penn)

2012-10-24T23:59:59.000Z

Note: This page contains sample records for the topic "x-ray diffraction imaging" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


161

X-ray imaging, spacecraft nuclear fission and cosmic ray contraband  

NLE Websites -- All DOE Office Websites (Extended Search)

R&D 100 Awards winners R&D 100 Awards winners X-ray imaging, spacecraft nuclear fission and cosmic ray contraband detection score R&D 100 awards R&D Magazine announced the winners and three technologies from Los Alamos National Laboratory and its partners are among the honorees. July 8, 2013 MiniMAX is a battery powered, digital x-ray imaging system that is completely self-contained, lightweight, compact and portable. MiniMAX is a battery powered, digital x-ray imaging system that is completely self-contained, lightweight, compact and portable. Contact Nancy Ambrosiano Communications Office (505) 667-0471 Email "The innovation and creativity shown in this year's awards is truly inspiring. It gives me great confidence in the Laboratory's intellectual vitality and ongoing role in national security science. Congratulations to

162

Integration of a broad beam ion source with a high-temperature x-ray diffraction vacuum chamber  

Science Conference Proceedings (OSTI)

Here, the integration of a low energy, linearly variable ion beam current density, mechanically in situ adjustable broad beam ion source with a high-temperature x-ray diffraction (XRD) vacuum chamber is reported. This allows in situ XRD investigation of phase formation and evolution processes induced by low energy ion implantation. Special care has been taken to an independent adjustment of the ion beam for geometrical directing towards the substrate, a 15 mm small ion source exit aperture to avoid a secondary sputter process of the chamber walls, linearly variable ion current density by using a pulse length modulation (PLM) for the accelerating voltages without changing the ion beam density profile, nearly homogeneous ion beam distribution over the x-ray footprint, together with easily replaceable Kapton{sup Registered-Sign} windows for x-rays entry and exit. By combining a position sensitive x-ray detector with this PLM-modulated ion beam, a fast and efficient time resolved investigation of low energy implantation processes is obtained in a compact experimental setup.

Manova, D.; Bergmann, A.; Maendl, S.; Neumann, H.; Rauschenbach, B. [Leibniz-Institut fuer Oberflaechenmodifizierung e. V., Permoserstr. 15, 04318 Leipzig (Germany)

2012-11-15T23:59:59.000Z

163

Nanoscale X-Ray Imaging - Programmaster.org  

Science Conference Proceedings (OSTI)

Study of Charge-Ordering in Manganites via Serial Femtosecond Crystallography · XFEL Materials Imaging at the LCLS CXI Endstation ...

164

In Situ X-ray Diffraction Studies of Cathode Materials in Lithium Batteries  

SciTech Connect

There is an increasing interest in lithiated transition metal oxides because of their use as cathodes in lithium batteries. LiCoO{sub 2}, LiNiO{sub 2} and LiMn{sub 2}O{sub 4} are the three most widely used and studied materials, At present, although it is relative expensive and toxic, LiCoO{sub 2} is the material of choice in commercial lithium ion batteries because of its ease of manufacture, better thermal stability and cycle life. However, the potential use of lithium ion batteries with larger capacity for power tools and electric vehicles in the future will demand new cathode materials with higher energy density, lower cost and better thermal stability. LiNiO{sub 2} is isostructural with LiCoO{sub 2}. It offers lower cost and high energy density than LiCoO{sub 2}. However, it has much poorer thermal stability than LiCoO{sub 2}, in the charged (delithiated) state. Co, Al, and other elements have been used to partially replace Ni in LiNiO{sub 2} system in order to increase the thermal stability. LiMn{sub 2}O{sub 4} has the highest thermal stability and lowest cost and toxicity. However, the low energy density and poor cycle life at elevated temperature are the major obstacles for this material. In order to develop safer, cheaper, and better performance cathode materials, the in-depth understanding of the relationships between the thermal stability and structure, performance and structure are very important. The performance here includes energy density and cycle life of the cathode materials. X-ray diffraction (XRD) is one of the most powerful tools to study these relationships. The pioneer ex situ XRD work on cathode materials for lithium batteries was done by Ohzuku. His XRD studies on LiMn{sub 2}O{sub 4}, LiCoO{sub 2}, LiNiO{sub 2}, LiNi{sub 0.5}Co{sub 0.5}O{sub 2}, and LiAl{sub x}Ni{sub 1-x}O{sub 2} cathodes at different states of charge have provided important guidelines for the development of these new materials. However, the kinetic nature of the battery system definitely requires an in situ XRD technique to study the detail structural changes of the system during charge and discharge. The in situ XRD technique was used by Reimers, Li,and Dahn to study the LiCoO{sub 2}, LiNiO{sub 2}, and LiMn{sub 2}O{sub 4} systems. Their results of these studies have demonstrated that in situ XRD can provide more detailed information about the cathode material structural changes during charge-discharge. Conventional x-ray sources were used in these studies and the beryllium windows were used in the in situ cells. Provisions were made to prevent corrosion of the beryllium windows during charge-discharge. For this reason, the in situ cells were often designed quite differently than a real battery. More seriously, the problem of beryllium corrosion restricted the voltage range of the cell below 4.5 V. This limited the use of this technique to study the effects of overcharge which is very important to the thermal stability of the cathodes. Using the plastic lithium battery technology, Amatucci, Tarascon, and Klein constructed an in situ XRD cell, which allows structural investigations at voltages greater than 5 V without any beryllium window corrosion. However, all of these in situ XRD studies using conventional x-ray sources probe the cell in reflection geometry. Therefore, the observed structural changes are predominantly from the top few microns of the electrode coating, which might not be representative for the whole coating during charge-discharge especially when the rate is high.

Yang, X. Q.; Sun, X.; McBreen, J.; Mukerjee, S.; Gao, Yuan; Yakovleva, M. V.; Xing, X. K.; Daroux, M. L.

1998-11-01T23:59:59.000Z

165

In situ high-pressure x-ray diffraction study of H[subscript 2]O ice VII  

DOE Green Energy (OSTI)

Ice VII was examined over the entire range of its pressure stability by a suite of x-ray diffraction techniques in order to understand a number of unexplained characteristics of its high-pressure behavior. Axial and radial polycrystalline (diamond anvil cell) x-ray diffraction measurements reveal a splitting of diffraction lines accompanied by changes in sample texture and elastic anisotropy. In situ laser heating of polycrystalline samples resulted in the sharpening of diffraction peaks due to release of nonhydrostatic stresses but did not remove the splitting. Radial diffraction measurements indicate changes in strength of the material at this pressure. Taken together, these observations provide evidence for a transition in ice VII near 14 GPa involving changes in the character of the proton order/disorder. The results are consistent with previous reports of changes in phase boundaries and equation of state at this pressure. The transition can be interpreted as ferroelastic with the appearance of spontaneous strain that vanishes at the hydrogen bond symmetrization transition near 60 GPa.

Somayazulu, M.; Shu, J.; Zha, C.-S.; Goncharov, A.F. (CIW)

2008-06-30T23:59:59.000Z

166

X-Ray Imaging Current-Driven Magnetic Domain-Wall Motion in Nanowires  

NLE Websites -- All DOE Office Websites (Extended Search)

X-Ray Imaging Current-Driven Magnetic Domain-Wall Motion in Nanowires Print X-Ray Imaging Current-Driven Magnetic Domain-Wall Motion in Nanowires Print The quest to increase both computer data-storage density and the speed at which one can read and write the information remains unconsummated. One novel concept is based on the use of a local electric current to push magnetic domain walls along a thin nanowire. A German, Korean, Berkeley Lab team has used the x-ray microscope XM-1 at the ALS to demonstrate that magnetic domain walls in curved permalloy nanowires can be moved at high speed by injecting nanosecond pulses of spin-polarized currents into the wires, but the motion is largely stochastic. This result will have an impact on the current development of magnetic storage devices in which data is moved electronically rather than mechanically as in computer disk drives.

167

X-Ray Imaging Current-Driven Magnetic Domain-Wall Motion in Nanowires  

NLE Websites -- All DOE Office Websites (Extended Search)

X-Ray Imaging Current-Driven Magnetic Domain-Wall Motion in Nanowires Print X-Ray Imaging Current-Driven Magnetic Domain-Wall Motion in Nanowires Print The quest to increase both computer data-storage density and the speed at which one can read and write the information remains unconsummated. One novel concept is based on the use of a local electric current to push magnetic domain walls along a thin nanowire. A German, Korean, Berkeley Lab team has used the x-ray microscope XM-1 at the ALS to demonstrate that magnetic domain walls in curved permalloy nanowires can be moved at high speed by injecting nanosecond pulses of spin-polarized currents into the wires, but the motion is largely stochastic. This result will have an impact on the current development of magnetic storage devices in which data is moved electronically rather than mechanically as in computer disk drives.

168

X-Ray Imaging Current-Driven Magnetic Domain-Wall Motion in Nanowires  

NLE Websites -- All DOE Office Websites (Extended Search)

X-Ray Imaging Current-Driven Magnetic Domain-Wall Motion in Nanowires Print X-Ray Imaging Current-Driven Magnetic Domain-Wall Motion in Nanowires Print The quest to increase both computer data-storage density and the speed at which one can read and write the information remains unconsummated. One novel concept is based on the use of a local electric current to push magnetic domain walls along a thin nanowire. A German, Korean, Berkeley Lab team has used the x-ray microscope XM-1 at the ALS to demonstrate that magnetic domain walls in curved permalloy nanowires can be moved at high speed by injecting nanosecond pulses of spin-polarized currents into the wires, but the motion is largely stochastic. This result will have an impact on the current development of magnetic storage devices in which data is moved electronically rather than mechanically as in computer disk drives.

169

X-Ray Imaging Current-Driven Magnetic Domain-Wall Motion in Nanowires  

NLE Websites -- All DOE Office Websites (Extended Search)

X-Ray Imaging Current-Driven Magnetic Domain-Wall Motion in Nanowires Print X-Ray Imaging Current-Driven Magnetic Domain-Wall Motion in Nanowires Print The quest to increase both computer data-storage density and the speed at which one can read and write the information remains unconsummated. One novel concept is based on the use of a local electric current to push magnetic domain walls along a thin nanowire. A German, Korean, Berkeley Lab team has used the x-ray microscope XM-1 at the ALS to demonstrate that magnetic domain walls in curved permalloy nanowires can be moved at high speed by injecting nanosecond pulses of spin-polarized currents into the wires, but the motion is largely stochastic. This result will have an impact on the current development of magnetic storage devices in which data is moved electronically rather than mechanically as in computer disk drives.

170

X-Ray Imaging Current-Driven Magnetic Domain-Wall Motion in Nanowires  

NLE Websites -- All DOE Office Websites (Extended Search)

X-Ray Imaging Current-Driven Magnetic Domain-Wall Motion in Nanowires Print X-Ray Imaging Current-Driven Magnetic Domain-Wall Motion in Nanowires Print The quest to increase both computer data-storage density and the speed at which one can read and write the information remains unconsummated. One novel concept is based on the use of a local electric current to push magnetic domain walls along a thin nanowire. A German, Korean, Berkeley Lab team has used the x-ray microscope XM-1 at the ALS to demonstrate that magnetic domain walls in curved permalloy nanowires can be moved at high speed by injecting nanosecond pulses of spin-polarized currents into the wires, but the motion is largely stochastic. This result will have an impact on the current development of magnetic storage devices in which data is moved electronically rather than mechanically as in computer disk drives.

171

Novel x-ray imaging methods at the Nova Laser Facility  

Science Conference Proceedings (OSTI)

We are pursuing several novel x-ray imaging schemes to measure plasma parameters in inertial-confinement fusion experiments. This paper will review two quite successful approaches, the soft x-ray moire deflectometer, and the annular (ring) coded-aperture microscope. The deflectometer is the newer diagnostic, and this paper will concentrate on this topic. We will describe the operating principles of moire deflectometry, give the motivations for soft x-ray probing, describe the physical apparatus in detail, and present some sample images and results. The ring coded-aperture microscope has been described previously, so here we will only briefly review the principle of the instrument. We will concentrate on the signal-to-noise ratio calculations that motivate the use of annular coded apertures, and describe recent work to predict and measure the resolution of the instrument.

Ress, D.; DaSilva, L.B.; London, R.A.; Trebes, J.E.; Lerche, R.A. [Lawrence Livermore National Lab., CA (United States); Bradley, D.K. [Rochester Univ., NY (United States). Lab. for Laser Energetics

1994-06-06T23:59:59.000Z

172

Determination of the solubility of tin indium oxide using in situ and ex x-ray diffraction  

SciTech Connect

A novel approach to determine the thermodynamic solubility of tin in indium oxide via the exsolution from tin overdoped nano-ITO powders is presented. High-energy, in situ and ex situ synchrotron X-ray diffraction was utilized to study the solubility limit at temperatures ranging from 900 C to 1375 C. The tin exsolution from overdoped nanopowders and the formation of In{sub 4}Sn{sub 3}O{sub 12} were observed in situ during the first 4-48 h of high-temperature treatment. Samples annealed between 900 C and 1175 C were also studied ex situ with heat treatments for up to 2060 h. Structural results obtained from Rietveld analysis include compositional phase analysis, atomic positions, and lattice parameters. The tin solubility in In{sub 2}O{sub 3} was determined using the phase analysis compositions from X-ray diffraction and the elemental compositions obtained from X-ray fluorescence. Experimental complications that can lead to incorrect tin solubility values in the literature are discussed.

Gonzalez, G. B.; Mason, T. O.; Okasinski, J. S.; Buslaps, T.; Honkimaki, V. (X-Ray Science Division); (DePaul Univ.); (Northwestern Univ.); (European Synchrotron Radiation Facility, Grenoble, France)

2012-02-01T23:59:59.000Z

173

Observation and simulation of hard x ray photoelectron diffraction to determine polarity of polycrystalline zinc oxide films with rotation domains  

SciTech Connect

X ray photoelectron diffraction (XPD) patterns of polar zinc oxide (ZnO) surfaces were investigated experimentally using hard x rays and monochromatized Cr K{alpha} radiation and theoretically using a cluster model approach and a dynamical Bloch wave approach. We focused on photoelectrons emitted from the Zn 2p{sub 3/2} and O 1s orbitals in the analysis. The obtained XPD patterns for the (0001) and (0001) surfaces of a ZnO single crystal were distinct for a given emitter and polarity. Polarity determination of c-axis-textured polycrystalline ZnO thin films was also achieved with the concept of XPD, even though the in-plane orientation of the columnar ZnO grains was random.

Williams, Jesse R.; Adachi, Yutaka; Ohashi, Naoki [International Center for Materials Nanoarchitectonics (MANA), National Institute for Materials Science (NIMS), 1-1 Namiki, Tsukuba, Ibaraki 305-0044 (Japan); NIMS Saint-Gobain Research Center of Excellence for Advanced Materials, NIMS, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047 (Japan); Pis, Igor [Synchrotron X-ray Station at SPring-8, NIMS, SPring-8, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan); Department of Surface and Plasma Science, Faculty of Mathematics and Physics, Charles University, V Holesovickach 2, Prague 8 18000 (Czech Republic); Kobata, Masaaki [Synchrotron X-ray Station at SPring-8, NIMS, SPring-8, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan); Winkelmann, Aimo [Max-Planck-Institut fuer Mikrostrukturphysik, Weinberg 2, D-06120 Halle (Saale) (Germany); Matsushita, Tomohiro [Japan Synchrotron Radiation Research Institute (JASRI), SPring-8, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148 (Japan); Kobayashi, Keisuke [Synchrotron X-ray Station at SPring-8, NIMS, SPring-8, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan); Hiroshima Synchrotron Radiation Center, Hiroshima University, 2-313 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-0046 (Japan)

2012-02-01T23:59:59.000Z

174

Novel cell design for combined in situ acoustic emission and x-ray diffraction study during electrochemical cycling of batteries  

Science Conference Proceedings (OSTI)

An in situ acoustic emission (AE) and x-ray diffraction cell for use in the study of battery electrode materials has been designed and tested. This cell uses commercially available coin cell hardware retrofitted with a metalized polyethylene terephthalate (PET) disk, which acts as both an x-ray window and a current collector. In this manner, the use of beryllium and its associated cost and hazards is avoided. An AE sensor may be affixed to the cell face opposite the PET window in order to monitor degradation effects, such as particle fracture, during cell cycling. Silicon particles, which were previously studied by the AE technique, were tested in this cell as a model material. The performance of these cells compared well with unmodified coin cells, while providing information about structural changes in the active material as the cell is repeatedly charged and discharged.

Rhodes, Kevin; Meisner, Roberta; Daniel, Claus [Materials Science and Technology Division, Oak Ridge National Laboratory, 1 Bethel Valley Rd., MS 6083, Oak Ridge, Tennessee 37931-6083 (United States); Materials Science and Engineering Department, University of Tennessee, 434 Dougherty Hall, Knoxville, Tennessee 37996-2200 (United States); Kirkham, Melanie; Parish, Chad M.; Dudney, Nancy [Materials Science and Technology Division, Oak Ridge National Laboratory, 1 Bethel Valley Rd., MS 6083, Oak Ridge, Tennessee 37931-6083 (United States)

2011-07-15T23:59:59.000Z

175

Novel Cell Design for Combined In Situ Acoustic Emission and X-ray Diffraction of Cycling Lithium Ion Batteries  

SciTech Connect

An in situ acoustic emission (AE) and X-ray diffraction (XRD) cell for use in the study of battery electrode materials has been devised and tested. This cell uses commercially available coin cell hardware retrofitted with a metalized polyethylene terephthalate (PET) disk which acts as both an X-ray window and a current collector. In this manner the use of beryllium and its associated cost and hazard is avoided. An AE sensor may be affixed to the cell face opposite the PET window in order to monitor degradation effects, such as particle fracture, during cell cycling. Silicon particles which were previously studied by the AE technique were tested in this cell as a model material. The performance of these cells compared well with unmodified coin cells while providing information about structural changes in the active material as the cell is repeatedly charged and discharged.

Rhodes, Kevin J [ORNL; Kirkham, Melanie J [ORNL; Meisner, Roberta Ann [ORNL; Parish, Chad M [ORNL; Dudney, Nancy J [ORNL; Daniel, Claus [ORNL

2011-01-01T23:59:59.000Z

176

A diamond anvil cell with resistive heating for high pressure and high temperature x-ray diffraction and absorption studies  

SciTech Connect

In this paper we describe a prototype of a diamond anvil cell (DAC) for high pressure/high temperature studies. This DAC combines the use of a resistive oven of 250 W power in a very small volume, associated with special conical seats for Boehler-type diamond anvils in order to have a large angular acceptance. To protect the diamond anvils from burning and to avoid the oven oxidation, the heated DAC is enclosed in a vacuum chamber. The assemblage was used to study the melting curve of germanium at high pressure (up to 20 GPa) and high temperature (up to 1200 K) using x-ray diffraction and x-ray absorption spectroscopy.

Pasternak, Sebastien; Aquilanti, Giuliana; Pascarelli, Sakura; Zhang Lin [European Synchrotron Radiation Facility, 6 rue Jules Horowitz, 38043 Grenoble, Cedex (France); Poloni, Roberta [European Synchrotron Radiation Facility, 6 rue Jules Horowitz, 38043 Grenoble, Cedex (France); Institut de Ciencia de Materials de Barcelona (CSIC), Campus de la UAB, E-08193 Bellaterra, Barcelona Spain (Spain); Canny, Bernard [IMPMC-CNRS UMR, 7590 Universite Paris VI, 140 rue de Lourmel, 75015 Paris (France); Coulet, Marie-Vanessa [IM2NP-UMR CNRS, 6242 Universite Paul Cezanne Campus de St Jerome, 13397 Marseille Cedex 20 (France)

2008-08-15T23:59:59.000Z

177

X-ray imaging for environmental science Chris Jacobsen  

E-Print Network (OSTI)

at CNM, Electron Microscopy Center, plus computation. 16 #12;Ultrafast imaging of fuel injector sprays, Chris Jacobsen, Robert Towers. Not shown: Sue Wirick, Chris Peltzer. Phase contrast and fluorescence

178

Formation of delta ferrite in 9 wt.% Cr steel investigated by in-situ X-ray diffraction using synchrotron radiation  

E-Print Network (OSTI)

In-situ X-ray diffraction (XRD) measurements using high energy synchrotron radiation were performed to monitor in real time the formation of delta ferrite in a martensitic 9 wt pct chromium steel under simulated weld thermal ...

Mayr, P.

179

Cocoa Butter and Related CompoundsChapter 14 New Method to Study Molecular Interactions in Fats—Synchrotron Radiation Microbeam X-ray Diffraction  

Science Conference Proceedings (OSTI)

Cocoa Butter and Related Compounds Chapter 14 New Method to Study Molecular Interactions in Fats—Synchrotron Radiation Microbeam X-ray Diffraction Food Science Health Nutrition eChapters Food Science & Technology Health - Nutrition - Bioc

180

Crystallization and Solidification Properties of LipidsChapter 3 Simultaneous Exam Structural/Thermal Behaviors of Fatsby Coupled X-ray Diffraction and Differential Scanning Calorimetry  

Science Conference Proceedings (OSTI)

Crystallization and Solidification Properties of Lipids Chapter 3 Simultaneous Exam Structural/Thermal Behaviors of Fatsby Coupled X-ray Diffraction and Differential Scanning Calorimetry Health Nutrition Biochemistry eChapters Health - N

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181

Structure-Function Analysis of Edible FatsChapter 3 Powder X-ray Diffraction of Triglycerides in the Study of Polymorphism  

Science Conference Proceedings (OSTI)

Structure-Function Analysis of Edible Fats Chapter 3 Powder X-ray Diffraction of Triglycerides in the Study of Polymorphism Methods and Analyses eChapters Food Science & Technology Health - Nutrition - Biochemistry Processing Methods - An

182

Soft X-Ray Imaging of spin dynamics at high spatial and temporalresolution  

Science Conference Proceedings (OSTI)

Soft X-ray microscopy provides element specific magnetic imaging with a spatial resolution down to 15nm. At XM-1, the full-field soft X-ray microscope at the Advanced Light Source in Berkeley, a stroboscopic pump and probe setup has been developed to study fast magnetization dynamics in ferromagnetic elements with a time resolution of 70ps which is set by the width of the X-ray pulses from the synchrotron. Results obtained with a 2 {micro}m x 4 {micro}m x 45nm rectangular permalloy sample exhibiting a seven domain Landau pattern reveal dynamics up to several nsec after the exciting magnetic field pulse. Domain wall motion, a gyrotropic vortex motion, and a coupling between vortices in the rectangular geometry are observed.

Mesler, Brooke L.; Fischer, Peter; Chao, Weilun; Anderson, Erik H.

2007-06-01T23:59:59.000Z

183

X-ray intravital microscopy for functional imaging in rat hearts using synchrotron radiation coronary microangiography  

SciTech Connect

An X-ray intravital microscopy technique was developed to enable in vivo visualization of the coronary, cerebral, and pulmonary arteries in rats without exposure of organs and with spatial resolution in the micrometer range and temporal resolution in the millisecond range. We have refined the system continually in terms of the spatial resolution and exposure time. X-rays transmitted through an object are detected by an X-ray direct-conversion type detector, which incorporates an X-ray SATICON pickup tube. The spatial resolution has been improved to 6 {mu}m, yielding sharp images of small arteries. The exposure time has been shortened to around 2 ms using a new rotating-disk X-ray shutter, enabling imaging of beating rat hearts. Quantitative evaluations of the X-ray intravital microscopy technique were extracted from measurements of the smallest-detectable vessel size and detection of the vessel function. The smallest-diameter vessel viewed for measurements is determined primarily by the concentration of iodinated contrast material. The iodine concentration depends on the injection technique. We used ex vivo rat hearts under Langendorff perfusion for accurate evaluation. After the contrast agent is injected into the origin of the aorta in an isolated perfused rat heart, the contrast agent is delivered directly into the coronary arteries with minimum dilution. The vascular internal diameter response of coronary arterial circulation is analyzed to evaluate the vessel function. Small blood vessels of more than about 50 {mu}m diameters were visualized clearly at heart rates of around 300 beats/min. Vasodilation compared to the control was observed quantitatively using drug manipulation. Furthermore, the apparent increase in the number of small vessels with diameters of less than about 50 {mu}m was observed after the vasoactive agents increased the diameters of invisible small blood vessels to visible sizes. This technique is expected to offer the potential for direct investigation of mechanisms of vascular dysfunctions.

Umetani, K. [Japan Synchrotron Radiation Research Institute, SPring-8, Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan); Fukushima, K. [National Cerebral and Cardiovascular Center Hospital, Fujishirodai, Suita-shi, Osaka 565-8565 (Japan)

2013-03-15T23:59:59.000Z

184

X-Ray Imaging Current-Driven Magnetic Domain-Wall Motion in Nanowires  

NLE Websites -- All DOE Office Websites (Extended Search)

X-Ray Imaging Current-Driven X-Ray Imaging Current-Driven Magnetic Domain-Wall Motion in Nanowires X-Ray Imaging Current-Driven Magnetic Domain-Wall Motion in Nanowires Print Wednesday, 26 September 2007 00:00 The quest to increase both computer data-storage density and the speed at which one can read and write the information remains unconsummated. One novel concept is based on the use of a local electric current to push magnetic domain walls along a thin nanowire. A German, Korean, Berkeley Lab team has used the x-ray microscope XM-1 at the ALS to demonstrate that magnetic domain walls in curved permalloy nanowires can be moved at high speed by injecting nanosecond pulses of spin-polarized currents into the wires, but the motion is largely stochastic. This result will have an impact on the current development of magnetic storage devices in which data is moved electronically rather than mechanically as in computer disk drives.

185

X-Ray Imaging of the Dynamic Magnetic Vortex Core Deformation  

NLE Websites -- All DOE Office Websites (Extended Search)

X-Ray Imaging of the Dynamic X-Ray Imaging of the Dynamic Magnetic Vortex Core Deformation X-Ray Imaging of the Dynamic Magnetic Vortex Core Deformation Print Wednesday, 25 November 2009 00:00 Magnetic thin-film nanostructures can exhibit a magnetic vortex state in which the magnetization vectors lie in the film plane and curl around in a closed loop. At the very center of the vortex, a small, stable core exists where the magnetization points either up or down out of the plane. Three years ago, the discovery of an easy core reversal mechanism at the ALS not only made the possibility of using such systems as magnetic memories much more realistic, it also initiated investigation of the core switching mechanism itself. Now, a Belgian-German-ALS collaboration has used high-resolution, time-resolved, magnetic x-ray microscopy to experimentally reveal the first step of the reversal process: the dynamic deformation of the vortex core. The group also measured a critical vortex velocity above which reversal occurs. Both these observations provide the first experimental support for the postulated reversal mechanism.

186

Power efficient asynchronous multiplexer for X-ray sensors in medical imaging analog front-end electronics  

Science Conference Proceedings (OSTI)

This paper presents a new power efficient asynchronous multiplexer (MUX) for application in analog front-end electronics (AFE) used in X-ray medical imaging systems. Contrary to typical synchronous MUXes that have to be controlled by a clock, this circuit ... Keywords: Analog front end, Asynchronous circuits, Medical imaging, Multiplexers, X-ray detection

Rafa? D?ugosz; Pierre-André Farine; Kris Iniewski

2011-01-01T23:59:59.000Z

187

X-ray diffraction and scattering studies of coal constituents. Final technical report, January 1-December 31, 1983  

DOE Green Energy (OSTI)

The general objective of this work has been to use x-ray diffraction and scattering to examine whole coals, coal macerals and minerals in order to perform the following studies: (1) to identify and explain differences in vitrinites and framboids from various coals; (2) to correlate differences with basic coal compositions and properties; and (3) to determine the systematic variability in the micro compositional variation of macerals. The accomplishments have been: (a) the development of the Fourier transform technique to do proximate and ultimate analyses in a quick fashion; and (b) the investigation of the structure of pyrite framboids and preliminary studies of coal macerals. 3 figures, 12 tables.

Pavlovic, A. S.; Renton, J. T.

1984-03-15T23:59:59.000Z

188

X-ray imaging with grazing-incidence microscopes developed for the LIL program  

SciTech Connect

This article describes x-ray imaging with grazing-incidence microscopes, developed for the experimental program carried out on the Ligne d'Integration Laser (LIL) facility [J. P. Le Breton et al., Inertial Fusion Sciences and Applications 2001 (Elsevier, Paris, 2002), pp. 856-862] (24 kJ, UV--0.35 nm). The design includes a large target-to-microscope (400-700 mm) distance required by the x-ray ablation issues anticipated on the Laser MegaJoule facility [P. A. Holstein et al., Laser Part. Beams 17, 403 (1999)] (1.8 MJ) which is under construction. Two eight-image Kirkpatrick-Baez microscopes [P. Kirkpatrick and A. V. Baez J. Opt. Soc. Am. 38, 766 (1948)] with different spectral wavelength ranges and with a 400 mm source-to-mirror distance image the target on a custom-built framing camera (time resolution of {approx}80 ps). The soft x-ray version microscope is sensitive below 1 keV and its spatial resolution is better than 30 {mu}m over a 2-mm-diam region. The hard x-ray version microscope has a 10 {mu}m resolution over an 800-{mu}m-diam region and is sensitive in the 1-5 keV energy range. Two other x-ray microscopes based on an association of toroidal/spherical surfaces (T/S microscopes) produce an image on a streak camera with a spatial resolution better than 30 {mu}m over a 3 mm field of view in the direction of the camera slit. Both microscopes have been designed to have, respectively, a maximum sensitivity in the 0.1-1 and 1-5 keV energy range. We present the original design of these four microscopes and their test on a dc x-ray tube in the laboratory. The diagnostics were successfully used on LIL first experiments early in 2005. Results of soft x-ray imaging of a radiative jet during conical shaped laser interaction are shown.

Rosch, R.; Boutin, J. Y.; Le Breton, J. P.; Gontier, D.; Jadaud, J. P.; Reverdin, C.; Soullie, G.; Lidove, G.; Maroni, R. [CEA/DIF, BP 12, 91680 Bruyeres-Le-Chatel (France)

2007-03-15T23:59:59.000Z

189

A new aperture for neutron and x-ray imaging of inertial confinement fusion experiments  

Science Conference Proceedings (OSTI)

Recent neutron imaging of experiments at the National Ignition Facility has provided useful information about the hotspot shape and cold-fuel distribution and has also given insight into avenues for improvement. Neutron image reconstruction depends on accurate pointing information because the point-spread function of the neutron aperture is not shift invariant. Current pointing techniques are limited in their accuracy and rely upon detailed information about the as-built structure of the array, which is difficult to determine. We present a technique for extracting high-precision pointing information from both neutron and x-ray images, and a new aperture design with features to facilitate this technique, and allow future co-registration of neutron and x-ray images.

Danly, C. R.; Grim, G. P.; Guler, N.; Intrator, M. H.; Merrill, F. E.; Volegov, P.; Wilde, C. H. [Los Alamos National Laboratory, PO Box 1663, Los Alamos, New Mexico 87545 (United States)

2012-10-15T23:59:59.000Z

190

Two-Dimensional X-ray Diffraction for Advanced Materials Analysis  

Science Conference Proceedings (OSTI)

Deformation Of Shape Memory Alloys Under Biaxial Loading .... Software Tools for the Monitoring, Analysis and Interpretation of Engineering Neutron Diffraction

191

High resolution biomedical imaging system with direct detection of x-rays via a charge coupled device  

DOE Patents (OSTI)

An imaging system is provided for direct detection of x-rays from an irradiated biological tissue. The imaging system includes an energy source for emitting x-rays toward the biological tissue and a charge coupled device (CCD) located immediately adjacent the biological tissue and arranged transverse to the direction of irradiation along which the x-rays travel. The CCD directly receives and detects the x-rays after passing through the biological tissue. The CCD is divided into a matrix of cells, each of which individually stores a count of x-rays directly detected by the cell. The imaging system further includes a pattern generator electrically coupled to the CCD for reading a count from each cell. A display device is provided for displaying an image representative of the count read by the pattern generator from the cells of the CCD.

Atac, Muzaffer (Wheaton, IL); McKay, Timothy A. (Ann Arbor, MI)

1998-01-01T23:59:59.000Z

192

Synchrotron X-ray diffraction study of texture evolution in 904L stainless steel under dynamic shock compression  

SciTech Connect

The influence of strain rate on development of deformation texture under a dynamic shock compression of a 904L stainless steel was quantitatively investigated using synchrotron X-ray diffraction and crystallographic orientation distribution function (ODF) analysis. Split-Hopkinson Pressure Bar technique was used to generate a high strain rate of > 103 s-1 for preparing the deformed samples. Starting with an almost random texture in a solution treatment condition, the deformed material developed several typical texture components, such as ‘Goss’ texture and ‘Brass’ texture. Compared to the texture components displayed in the state of quasi-static compression deformation, it was found that the high-speed deformation generated much weaker texture components. In combination with the change in microstructures observed by EBSD and TEM technique, the high-energy X-ray diffraction provides a powerful tool for characterizing the strain-rate dependence of grain rotation at each stage of deformation. The deformation heterogeneity evident in our experiment can be explained by a transition of deformation mechanism from the dislocation/twin-dominated mode to shear-band-dominated one with increasing strain rate.

Li, Nanan; Wang, Y. D.; Peng, R. Lin; Sun, Xin; Ren, Yang; Wang, L.; Cai, H. N.

2011-01-01T23:59:59.000Z

193

LOW TEMPERATURE X-RAY DIFFRACTION STUDIES OF NATURAL GAS HYDRATE SAMPLES FROM THE GULF OF MEXICO  

SciTech Connect

Clathrate hydrates of methane and other small alkanes occur widespread terrestrially in marine sediments of the continental margins and in permafrost sediments of the arctic. Quantitative study of natural clathrate hydrates is hampered by the difficulty in obtaining pristine samples, particularly from submarine environments. Bringing samples of clathrate hydrate from the seafloor at depths without compromising their integrity is not trivial. Most physical property measurements are based on studies of laboratory-synthesized samples. Here we report X-ray powder diffraction measurements of a natural gas hydrate sample from the Green Canyon, Gulf of Mexico. The first data were collected in 2002 and revealed ice and structure II gas hydrate. In the subsequent time the sample has been stored in liquid nitrogen. More recent X-ray powder diffraction data have been collected as functions of temperature and time. This new data indicates that the larger sample is heterogeneous in ice content and shows that the amount of sII hydrate decreases with increasing temperature and time as expected. However, the dissociation rate is higher at lower temperatures and earlier in the experiment.

Rawn, Claudia J [ORNL; Sassen, Roger [Texas A& M University; Ulrich, Shannon M [ORNL; Phelps, Tommy Joe [ORNL; Chakoumakos, Bryan C [ORNL; Payzant, E Andrew [ORNL

2008-01-01T23:59:59.000Z

194

Wolter-like high resolution x-ray imaging microscope for Rayleigh Taylor instabilities studies  

SciTech Connect

In the context of the inertial confinement fusion, experiments have been carried out on the Phebus laser facility to study the Rayleigh-Taylor instabilities (RTIs) at the ablation front. Premodulated brominated plastic targets (25 {mu}m thick) with a modulation wavelength between 12 and 50 {mu}m were accelerated with a temporally shaped soft x-ray pulse emitted from a hohlraum with a maximum radiation temperature of about 115 eV. The RTI growth was measured by face-on radiography using a microscope coupled with an x-ray streak camera, which has spatial and temporal resolutions of about 5 {mu}m and 50 ps, respectively. The acceleration was derived from side-on velocity measurements. The microscope we have developed is a Wolter-like microscope which consists of two toroiedal mirrors. We will present the experimental and theoretical potentialities of this microscope: characterization with an x-ray generator and plasma laser x-ray source (Phebus facility) for two-dimensional (2D) and 1D time-resolved imaging studies. Spatial resolution of about 4 {mu}m was achieved in the 1-5 keV range. The Wolter-like constitutes an interesting device for laser plasma diagnostics and will be very useful in the Laser Megajoules experiments conducted with more powerful lasers.

Troussel, Ph.; Meyer, B.; Reverdin, R.; Angelier, B.; Lidove, G.; Salvatore, P.; Richard, A. [Commissariat a l'Energie Atomique, DAM-Ile de France, BP 12, 91680 Bruyeres-les-Chatel (France); Commissariat a l'Energie Atomique, Saclay 91191 (France); Commissariat a l'Energie Atomique, CESTA, BP2, 33114 Le Barp (France)

2005-06-15T23:59:59.000Z

195

Improved image quality for x-ray CT imaging of gel dosimeters  

Science Conference Proceedings (OSTI)

Purpose: This study provides a simple method for improving precision of x-ray computed tomography (CT) scans of irradiated polymer gel dosimetry. The noise affecting CT scans of irradiated gels has been an impediment to the use of clinical CT scanners for gel dosimetry studies. Methods: In this study, it is shown that multiple scans of a single PAGAT gel dosimeter can be used to extrapolate a ''zero-scan'' image which displays a similar level of precision to an image obtained by averaging multiple CT images, without the compromised dose measurement resulting from the exposure of the gel to radiation from the CT scanner. Results: When extrapolating the zero-scan image, it is shown that exponential and simple linear fits to the relationship between Hounsfield unit and scan number, for each pixel in the image, provide an accurate indication of gel density. Conclusions: It is expected that this work will be utilized in the analysis of three-dimensional gel volumes irradiated using complex radiotherapy treatments.

Kakakhel, M. B.; Kairn, T.; Kenny, J.; Trapp, J. V. [Faculty of Science and Technology, Queensland University of Technology, GPO Box 2434, Brisbane, Queesland 4001, Australia and Department of Physics and Applied Mathematics, DPAM, Pakistan Institute of Engineering and Applied Sciences, PO Nilore, Islamabad 45450 (Pakistan); Premion, The Wesley Medical Centre, Suite 1, 40 Chasely St, Auchenflower, Queensland 4066 (Australia); Premion, The Wesley Medical Centre, Suite 1, 40 Chasely St, Auchenflower, Queensland 4066, Australia and Australian Clinical Dosimetry Service, ARPANSA, Yallambie, Vic 3085 (Australia); Faculty of Science and Technology, Queensland University of Technology, GPO Box 2434, Brisbane, Ql d 4001 (Australia)

2011-09-15T23:59:59.000Z

196

IMAGE SEGMENTATION FOR PHASE-CONTRAST HARD X-RAY CMT OF C/C Gerard L. Vignoles  

E-Print Network (OSTI)

1 IMAGE SEGMENTATION FOR PHASE-CONTRAST HARD X-RAY CMT OF C/C COMPOSITES Gerard L. Vignoles/C composites, computerized microtomographs have been acquired with synchrotron radiation X-rays. Due ranging between 0° and 180°, were acquired each time using a Gd2O3S:Tb scintillator, a light amplification

Paris-Sud XI, Université de

197

Elemental and magnetic sensitive imaging using x-ray excited luminescence microscopy  

Science Conference Proceedings (OSTI)

We demonstrate the potential of x-ray excited luminescence microscopy for full-field elemental and magnetic sensitive imaging using a commercially available optical microscope, mounted on preexisting synchrotron radiation (SR) beamline end stations. The principal components of the instrument will be described. Bench top measurements indicate that a resolution of 1 {mu}m or better is possible; this value was degraded in practice due to vibrations and/or drift in the end station and associated manipulator. X-ray energy dependent measurements performed on model solar cell materials and lithographically patterned magnetic thin film structures reveal clear elemental and magnetic signatures. The merits of the apparatus will be discussed in terms of conventional SR imaging techniques.

Rosenberg, R. A.; Zohar, S.; Keavney, D. [Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Divan, R.; Rosenmann, D. [Center for Nanoscale Materials, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Mascarenhas, A.; Steiner, M. A. [National Renewable Energy Lab, Golden, Colorado 80401 (United States)

2012-07-15T23:59:59.000Z

198

Note: Grazing incidence small and wide angle x-ray scattering combined with imaging ellipsometry  

SciTech Connect

The combination of grazing incidence small angle x-ray scattering (GISAXS) and grazing incidence wide angle x-ray scattering (GIWAXS) with optical imaging ellipsometry is presented as an upgrade of the available measurement techniques at the wiggler beamline BW4 of the Hamburger Synchrotronstrahlungslabor. The instrument is introduced with the description of the alignment procedure to assure the measurement of imaging ellipsometry and GISAXS/GIWAXS on the same sample spot. To demonstrate the possibilities of the new instrument examples of morphological investigation on films made of poly(3-hexylthiophene) and [6,6]-phenyl-C{sub 61} butyric acid methyl ester as well as textured poly(9,9-dioctylfluorene-alt-benzo-thia-diazole) are shown.

Koerstgens, V.; Meier, R.; Ruderer, M. A.; Guo, S.; Chiang, H.-Y.; Mueller-Buschbaum, P. [Technische Universitaet Muenchen, Physik-Department, Lehrstuhl fuer Funktionelle Materialien, James-Franck-Str. 1, 85748 Garching (Germany); Perlich, J.; Roth, S. V.; Gehrke, R. [HASYLAB, DESY, Notkestr. 85, 22607, Hamburg (Germany)

2012-07-15T23:59:59.000Z

199

Atomic data for the ITER Core Imaging X-ray Spectrometer  

SciTech Connect

The parameters of the ITER core plasmas will be measured using the Core Imaging X-ray Spectrometer (CIXS), a high-resolution crystal spectrometer focusing on the L-shell spectra of highly ionized tungsten atoms. In order to correctly infer the plasma properties accurate atomic data are required. Here, some aspects of the underlying physics are discussed using experimental data and theoretical predictions from modeling.

Clementson, J; Beiersdorfer, P; Biedermann, C; Bitter, M; Delgado-Aparicio, L F; Graf, A; Gu, M F; Hill, K W; Barnsley, R

2012-06-15T23:59:59.000Z

200

Identification of Compounds and Phases Using X-Ray Powder Diffraction  

Science Conference Proceedings (OSTI)

Table 1(a)   Identification of powder diffraction pattern from Al 2 O 3 using the Hanawalt search method...pattern from Al 2 O 3 using the Hanawalt search method The diffracting angles and intensities (area under each peak)

Note: This page contains sample records for the topic "x-ray diffraction imaging" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

Tokamak x ray diagnostic instrumentation  

SciTech Connect

Three classes of x-ray diagnostic instruments enable measurement of a variety of tokamak physics parameters from different features of the x-ray emission spectrum. (1) The soft x-ray (1 to 50 keV) pulse-height-analysis (PHA) diagnostic measures impurity concentrations from characteristic line intensities and the continuum enhancement, and measures the electron temperature from the continuum slope. (2) The Bragg x-ray crystal spectrometer (XCS) measures the ion temperature and neutral-beam-induced toroidal rotation velocity from the Doppler broadening and wavelength shift, respectively, of spectral lines of medium-Z impurity ions. Impurity charge state distributions, precise wavelengths, and inner-shell excitation and recombination rates can also be studied. X rays are diffracted and focused by a bent crystal onto a position-sensitive detector. The spectral resolving power E/..delta..E is greater than 10/sup 4/ and time resolution is 10 ms. (3) The x-ray imaging system (XIS) measures the spatial structure of rapid fluctuations (0.1 to 100 kHZ) providing information on MHD phenomena, impurity transport rates, toroidal rotation velocity, plasma position, and the electron temperature profile. It uses an array of silicon surface-barrier diodes which view different chords of the plasma through a common slot aperture and operate in current (as opposed to counting) mode. The effectiveness of shields to protect detectors from fusion-neutron radiation effects has been studied both theoretically and experimentally.

Hill, K.W.; Beiersdorfer, P.; Bitter, M.; Fredrickson, E.; Von Goeler, S.; Hsuan, H.; Johnson, L.C.; Liew, S.L.; McGuire, K.; Pare, V.

1987-01-01T23:59:59.000Z

202

Crystallization and preliminary X-ray diffraction analysis of Sfh3, a member of the Sec14 protein superfamily  

SciTech Connect

Sec14 is the major phosphatidylinositol (PtdIns)/phosphatidylcholine (PtdCho) transfer protein in the yeast Saccharomyces cerevisiae and is the founding member of the Sec14 protein superfamily. Recent functional data suggest that Sec14 functions as a nanoreactor for PtdCho-regulated presentation of PtdIns to PtdIns kinase to affect membrane trafficking. Extrapolation of this concept to other members of the Sec14 superfamily suggests a mechanism by which a comprehensive cohort of Sec14-like nanoreactors sense correspondingly diverse pools of lipid metabolites. In turn, metabolic information is translated to signaling circuits driven by phosphoinositide metabolism. Sfh3, one of five Sec14 homologs in yeast, exhibits several interesting functional features, including its unique localization to lipid particles and microsomes. This localization forecasts novel regulatory interfaces between neutral lipid metabolism and phosphoinositide signaling. To launch a detailed structural and functional characterization of Sfh3, the recombinant protein was purified to homogeneity, diffraction-quality crystals were produced and a native X-ray data set was collected to 2.2 {angstrom} resolution. To aid in phasing, SAD X-ray diffraction data were collected to 1.93 {angstrom} resolution from an SeMet-labeled crystal at the Southeast Regional Collaborative Access Team at the Advanced Photon Source. Here, the cloning and purification of Sfh3 and the preliminary diffraction of Sfh3 crystals are reported, enabling structural analyses that are expected to reveal novel principles governing ligand binding and functional specificity for Sec14-superfamily proteins.

Ren, Jihui; Schaaf, Gabriel; Bankaitis, Vytas A.; Ortlund, Eric A.; Pathak, Manish C. (Emory-MED); (UNC)

2012-03-26T23:59:59.000Z

203

Oxygen-diffusion limited metal combustions in Zr, Ti, and Fe foils: Time- and angle-resolved x-ray diffraction studies  

Science Conference Proceedings (OSTI)

The transient phase and chemical transformations of diffusion controlled metal combustions in bulk Zr, Ti, and Fe foils have been investigated, in situ, using novel time- and angle-resolved x-ray diffraction (TARXD). The TARXD employs monochromatic synchrotron x-rays and a fast-rotating diffracted beam chopper resolving the diffraction image temporally in time-resolution of {approx}45 {mu}s along the azimuth on a 2D pixel array detector. The metal foil strips (10-25 {mu}m in thickness) are ignited using a pulsed electrical heating with a typical heating rate of {approx}10{sup 6} K/s. The x-ray results indicate that the combustion occurs in molten metals, producing a wide range of stoichiometric solid oxides. It reflects an enhanced oxygen solubility and mobility of molten metals with respect to those of solid metals. However, the initial oxides formed are mainly oxygen-deficient metal oxides of ZrO, TiO, and FeO/Fe{sub 3}O{sub 4} - the lowest suboxides stable at these high temperatures. These transition metal monoxides further react with unreacted molten metals, yielding the secondary products of Zr{sub 3}O, Ti{sub 3}O, and Ti{sub 2}O - but not in FeO/Fe{sub 3}O{sub 4}. On the other hand, the higher stoichiometric oxides of ZrO{sub 2} and TiO{sub 2} are formed in the later time only on the metal surface. These results clearly indicate that the combustion process of metal strips is diffusion limited and strongly depends on the solubility and diffusivity of oxygen into molten metals. The time-resolved diffraction data reveals no evidence for metal oxidation in solids, but a series of temperature-induced polymorphic phase transitions. The dynamic thermal expansibility of Fe measured in the present fast heating experiments is similar to those in static conditions (3.3*10{sup -5}/K vs 3.5*10{sup -5}/K for {alpha}-Fe and 6.5*10{sup -5}/K versus 7.0*10{sup -5}/K for {gamma}-Fe).

Wei, Haoyan; Yoo, Choong-Shik; Chen, Jing-Yin; Shen, Guoyin (CIW); (WSU)

2012-04-30T23:59:59.000Z

204

Noise in x-ray grating-based phase-contrast imaging  

Science Conference Proceedings (OSTI)

Purpose: Grating-based x-ray phase-contrast imaging is a fast developing new modality not only for medical imaging, but as well for other fields such as material sciences. While these many possible applications arise, the knowledge of the noise behavior is essential. Methods: In this work, the authors used a least squares fitting algorithm to calculate the noise behavior of the three quantities absorption, differential phase, and dark-field image. Further, the calculated error formula of the differential phase image was verified by measurements. Therefore, a Talbot interferometer was setup, using a microfocus x-ray tube as source and a Timepix detector for photon counting. Additionally, simulations regarding this topic were performed. Results: It turned out that the variance of the reconstructed phase is only dependent of the total number of photons used to generate the phase image and the visibility of the experimental setup. These results could be evaluated in measurements as well as in simulations. Furthermore, the correlation between absorption and dark-field image was calculated. Conclusions: These results provide the understanding of the noise characteristics of grating-based phase-contrast imaging and will help to improve image quality.

Weber, Thomas; Bartl, Peter; Bayer, Florian; Durst, Juergen; Haas, Wilhelm; Michel, Thilo; Ritter, Andre; Anton, Gisela [ECAP--Erlangen Centre for Astroparticle Physics, University of Erlangen-Nuremberg, Erwin-Rommel-Str. 1, 91058 Erlangen (Germany); Pattern Recognition Lab, University of Erlangen-Nuremberg, Martensstr. 3, 91058 Erlangen, Germany and ECAP--Erlangen Centre for Astroparticle Physics, University of Erlangen-Nuremberg, Erwin-Rommel-Str. 1, 91058 Erlangen (Germany); ECAP--Erlangen Centre for Astroparticle Physics, University of Erlangen-Nuremberg, Erwin-Rommel-Str. 1, 91058 Erlangen (Germany)

2011-07-15T23:59:59.000Z

205

X-Ray Imaging of the Dynamic Magnetic Vortex Core Deformation  

NLE Websites -- All DOE Office Websites (Extended Search)

X-Ray Imaging of the Dynamic Magnetic Vortex Core Deformation Print X-Ray Imaging of the Dynamic Magnetic Vortex Core Deformation Print Magnetic thin-film nanostructures can exhibit a magnetic vortex state in which the magnetization vectors lie in the film plane and curl around in a closed loop. At the very center of the vortex, a small, stable core exists where the magnetization points either up or down out of the plane. Three years ago, the discovery of an easy core reversal mechanism at the ALS not only made the possibility of using such systems as magnetic memories much more realistic, it also initiated investigation of the core switching mechanism itself. Now, a Belgian-German-ALS collaboration has used high-resolution, time-resolved, magnetic x-ray microscopy to experimentally reveal the first step of the reversal process: the dynamic deformation of the vortex core. The group also measured a critical vortex velocity above which reversal occurs. Both these observations provide the first experimental support for the postulated reversal mechanism.

206

X-Ray Imaging of the Dynamic Magnetic Vortex Core Deformation  

NLE Websites -- All DOE Office Websites (Extended Search)

X-Ray Imaging of the Dynamic Magnetic Vortex Core Deformation Print X-Ray Imaging of the Dynamic Magnetic Vortex Core Deformation Print Magnetic thin-film nanostructures can exhibit a magnetic vortex state in which the magnetization vectors lie in the film plane and curl around in a closed loop. At the very center of the vortex, a small, stable core exists where the magnetization points either up or down out of the plane. Three years ago, the discovery of an easy core reversal mechanism at the ALS not only made the possibility of using such systems as magnetic memories much more realistic, it also initiated investigation of the core switching mechanism itself. Now, a Belgian-German-ALS collaboration has used high-resolution, time-resolved, magnetic x-ray microscopy to experimentally reveal the first step of the reversal process: the dynamic deformation of the vortex core. The group also measured a critical vortex velocity above which reversal occurs. Both these observations provide the first experimental support for the postulated reversal mechanism.

207

X-Ray Imaging of the Dynamic Magnetic Vortex Core Deformation  

NLE Websites -- All DOE Office Websites (Extended Search)

X-Ray Imaging of the Dynamic Magnetic Vortex Core Deformation Print X-Ray Imaging of the Dynamic Magnetic Vortex Core Deformation Print Magnetic thin-film nanostructures can exhibit a magnetic vortex state in which the magnetization vectors lie in the film plane and curl around in a closed loop. At the very center of the vortex, a small, stable core exists where the magnetization points either up or down out of the plane. Three years ago, the discovery of an easy core reversal mechanism at the ALS not only made the possibility of using such systems as magnetic memories much more realistic, it also initiated investigation of the core switching mechanism itself. Now, a Belgian-German-ALS collaboration has used high-resolution, time-resolved, magnetic x-ray microscopy to experimentally reveal the first step of the reversal process: the dynamic deformation of the vortex core. The group also measured a critical vortex velocity above which reversal occurs. Both these observations provide the first experimental support for the postulated reversal mechanism.

208

X-Ray Imaging of the Dynamic Magnetic Vortex Core Deformation  

NLE Websites -- All DOE Office Websites (Extended Search)

X-Ray Imaging of the Dynamic Magnetic Vortex Core Deformation Print X-Ray Imaging of the Dynamic Magnetic Vortex Core Deformation Print Magnetic thin-film nanostructures can exhibit a magnetic vortex state in which the magnetization vectors lie in the film plane and curl around in a closed loop. At the very center of the vortex, a small, stable core exists where the magnetization points either up or down out of the plane. Three years ago, the discovery of an easy core reversal mechanism at the ALS not only made the possibility of using such systems as magnetic memories much more realistic, it also initiated investigation of the core switching mechanism itself. Now, a Belgian-German-ALS collaboration has used high-resolution, time-resolved, magnetic x-ray microscopy to experimentally reveal the first step of the reversal process: the dynamic deformation of the vortex core. The group also measured a critical vortex velocity above which reversal occurs. Both these observations provide the first experimental support for the postulated reversal mechanism.

209

X-Ray Imaging of the Dynamic Magnetic Vortex Core Deformation  

NLE Websites -- All DOE Office Websites (Extended Search)

X-Ray Imaging of the Dynamic Magnetic Vortex Core Deformation Print X-Ray Imaging of the Dynamic Magnetic Vortex Core Deformation Print Magnetic thin-film nanostructures can exhibit a magnetic vortex state in which the magnetization vectors lie in the film plane and curl around in a closed loop. At the very center of the vortex, a small, stable core exists where the magnetization points either up or down out of the plane. Three years ago, the discovery of an easy core reversal mechanism at the ALS not only made the possibility of using such systems as magnetic memories much more realistic, it also initiated investigation of the core switching mechanism itself. Now, a Belgian-German-ALS collaboration has used high-resolution, time-resolved, magnetic x-ray microscopy to experimentally reveal the first step of the reversal process: the dynamic deformation of the vortex core. The group also measured a critical vortex velocity above which reversal occurs. Both these observations provide the first experimental support for the postulated reversal mechanism.

210

X-Ray Imaging of the Dynamic Magnetic Vortex Core Deformation  

NLE Websites -- All DOE Office Websites (Extended Search)

X-Ray Imaging of the Dynamic Magnetic Vortex Core Deformation Print X-Ray Imaging of the Dynamic Magnetic Vortex Core Deformation Print Magnetic thin-film nanostructures can exhibit a magnetic vortex state in which the magnetization vectors lie in the film plane and curl around in a closed loop. At the very center of the vortex, a small, stable core exists where the magnetization points either up or down out of the plane. Three years ago, the discovery of an easy core reversal mechanism at the ALS not only made the possibility of using such systems as magnetic memories much more realistic, it also initiated investigation of the core switching mechanism itself. Now, a Belgian-German-ALS collaboration has used high-resolution, time-resolved, magnetic x-ray microscopy to experimentally reveal the first step of the reversal process: the dynamic deformation of the vortex core. The group also measured a critical vortex velocity above which reversal occurs. Both these observations provide the first experimental support for the postulated reversal mechanism.

211

A line-imaging velocity interferometer technique for shock diagnostics without x-ray preheat limitation  

Science Conference Proceedings (OSTI)

A study was conducted with a line-imaging velocity interferometer on sandwich targets at the Shen Guang-III prototype laser facility in China, with the goal of eliminating the preheat effect. A sandwich target structure was used to reduce the x-ray preheat limitation (radiation temperature {approx}170 eV) in a radiative drive shock experiment. With a thick ablator, the preheat effect appeared before the shock arrived at the window. After adding a shield layer of high-Z material on the ablator, x-rays which penetrated the ablator were so weak that the blank-out effect could not be measured. This experiment indicates that the sandwich target may provide a valuable technique in experiments such as equation of state and shock timing for inertial confinement fusion studies.

Wang Feng; Peng Xiaoshi; Liu Shenye; Xu Tao; Mei Lusheng; Jiang Xiaohua; Ding Yongkun [Research Center of Laser Fusion, CAEP, P.O. Box 919-986, Mianyang 621900 (China)

2011-10-15T23:59:59.000Z

212

Evaluation of the sensitivity and fading characteristics of an image plate system for x-ray diagnostics  

SciTech Connect

Image plates (IPs) are a reusable recording media capable of detecting ionizing radiation, used to diagnose x-ray emission from laser-plasma experiments. Due to their superior performance characteristics in x-ray applications [C. C. Bradford, W. W. Peppler, and J. T. Dobbins III, Med. Phys. 26, 27 (1999) and J. Digit. Imaging. 12, 54 (1999)], the Fuji Biological Analysis System (BAS) IPs are fielded on x-ray diagnostics for the HELEN laser by the Plasma Physics Department at AWE. The sensitivities of the Fuji BAS IPs have been absolutely calibrated for absolute measurements of x-ray intensity in the energy range of 0-100 keV. In addition, the Fuji BAS IP fading as a function of time was investigated. We report on the characterization of three Fuji BAS IP responses to x-rays using a radioactive source, and discrete x-ray line energies generated by the Excalibur soft x-ray facility and the Defense Radiological Standards Centre filter-fluorescer hard x-ray system at AWE.

Meadowcroft, A. L.; Bentley, C. D.; Stott, E. N. [Plasma Physics Department, AWE Aldermaston, Reading, Berkshire RG7 4PR (United Kingdom)

2008-11-15T23:59:59.000Z

213

Structural Properties Studies of Zinc Oxide Thin Film Grown on Silicon Carbide by Means of X-ray Diffraction Technique  

Science Conference Proceedings (OSTI)

In this work, the structural properties of the zinc oxide (ZnO) thin film on silicon carbide (6H-SiC) grown by radio frequency sputtering technique are investigated thoroughly by means of X-ray diffraction (XRD) technique. Both conventional XRD phase analysis and rocking curve measurements are carried out in order to determine the crystalline structure and the crystalline quality of the ZnO sample. From the phase analysis, intense peaks correspond to ZnO(002), iC(006) and their multiple reflections, i.e. ZnO(004) and SiC(0012) are observed. This result suggests that the ZnO thin film is in wurzite structure. Through the simulation of XRD rocking curve of the ZnO(002) peak, the lattice mismatch of 5.49% is obtained.

Ching, C. G.; Ng, S. S.; Hassan, Z.; Hassan, H. Abu; Al-Hardan, N. H.; Abdullah, M. J. [Nano-optoelectronics Research and Technology Laboratory, School of Physics, Universiti Sains Malaysia, 11800, Penang (Malaysia)

2011-03-30T23:59:59.000Z

214

X-ray Diffraction Studies of Forward and Reverse Plastic Flow in Nanoscale Layers during Thermal Cycling  

Science Conference Proceedings (OSTI)

The biaxial stress-strain response of layers within Cu/Ni nanolaminates is determined from in-plane x-ray diffraction spectra during heating/cooling. Thinner (11 nm) Cu and Ni layers with coherent, cube-on-cube interfaces reach ~1.8 GPa (Cu) and ~2.9 GPa (Ni) without yielding. Thicker (21 nm) layers with semi-coherent interfaces exhibit unusual plastic phenomena, including extraordinary plastic work hardening rates, and forward vs. reverse plastic flow with small (~10%) changes in stress, and evidence that threshold plastic stress in Ni layers is altered by preceding plastic flow in Cu layers. Line energy, pinning strength, net interfacial dislocation density and hardness are provided.

Gram, Michael D [Ohio State University, Columbus; Carpenter, John S [Los Alamos National Laboratory (LANL); Payzant, E Andrew [ORNL; Misra, Amit [Los Alamos National Laboratory (LANL); Anderson, Peter M [Ohio State University, Columbus

2013-01-01T23:59:59.000Z

215

Novel Protein Crystal Growth Electrochemical Cell For Applications in X-ray Diffraction and Atomic Force Microscopy  

Science Conference Proceedings (OSTI)

A new crystal growth cell based on transparent indium tin oxide (ITO) glass-electrodes for electrochemically assisted protein crystallization allows for reduced nucleation and crystal quality enhancement. The crystallization behavior of lysozyme and ferritin was monitored as a function of the electric current applied to the growth cell. The X-ray diffraction analysis showed that for specific currents, the crystal quality is substantially improved. No conformational changes were observed in the 3D crystallographic structures determined for crystals grown under different electric current regimes. Finally, the strong crystal adhesion on the surface of ITO electrode because of the electroadhesion allows a sufficiently strong fixing of the protein crystals, to undergo atomic force microscopy investigations in a fluid cell.

G Gil-Alvaradejo; R Ruiz-Arellano; C Owen; A Rodriguez-Romero; E Rudino-Pinera; M Antwi; V Stojanoff; A Moreno

2011-12-31T23:59:59.000Z

216

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

SciTech Connect

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.

Fan Dawei; Zhou Wenge; Liu Yonggang; Xie Hongsen [Institute of Geochemistry of Earth's Deep Interior Materials and Fluid Interaction, Chinese Academy of Sciences, Guiyang 550002 (China); Wei Shuyi [Institute of Geochemistry of Earth's Deep Interior Materials and Fluid Interaction, Chinese Academy of Sciences, Guiyang 550002 (China); Graduate School of Chinese Academy of Sciences, Beijing 100049 (China); Ma Maining [Graduate School of Chinese Academy of Sciences, Beijing 100049 (China)

2010-05-15T23:59:59.000Z

217

Mathematical simulation and X-ray diffraction investigation of the crystal structure of 1-phenyl-1-tert-butyl-3-methyl-1,3-dihydroisobenzofuran  

SciTech Connect

An algorithm for using a priori generation of crystal structures by the discrete modeling method for the interpretation of data obtained from single-crystal X-ray diffraction experiments is considered. The crystal structure of 1-phenyl-1-tert-butyl-3-methyl-1,3-dihydroisobenzofuran is mathematically simulated using the discrete modeling of molecular packings and studied by X-ray diffraction. The simulation is performed for two isomers of the initial chemical compound that are possible from the viewpoint of the mechanism of the chemical reaction used in the synthesis of this compound. Appropriate models that can serve as starting models for solving and refining the crystal structure with the use of X-ray diffraction data are chosen from a complete set of calculated structural models in accordance with specific criteria. The structure is solved using a starting model calculated using the discrete modeling method and refined by the full-matrix least-squares procedure.

Maleev, A. V., E-mail: andr_mal@mail.ru; Zhitkov, I. K.; Potekhin, K. A. [Vladimir State Pedagogical University (Russian Federation)

2008-07-15T23:59:59.000Z

218

Imaging Antifungal Drug Molecules in Action using Soft X-Ray Tomography  

NLE Websites -- All DOE Office Websites (Extended Search)

Imaging Antifungal Drug Imaging Antifungal Drug Molecules in Action using Soft X-Ray Tomography Imaging Antifungal Drug Molecules in Action using Soft X-Ray Tomography Print Wednesday, 24 February 2010 00:00 Humankind has benefitted from a long and productive relationship with yeast. For example, fermentation by yeast is an essential step in the production of bread, beer, wine, and even biofuels. However, not all yeast are beneficial. One strain of yeast, Candida albicans, grows unnoticed on most peoples' skin and in the intestines. In response to certain environmental conditions, C. albicans can switch to a pathogenic phenotype that causes infection. Yeast infections are commonplace, and in otherwise healthy individuals are usually treatable with over-the-counter medications; however, individuals with weakened immune systems can have very serious systemic consequences from a yeast infection. Treating systemic yeast infections is becoming increasingly difficult due to the growing number of yeast strains that have developed resistance to existing antimicrobial drugs. Consequently, there is a pressing need to develop new types of drugs capable of circumventing yeast drug-resistance mechanisms. To this end Stanford, University of California, San Francisco and LBNL researchers have used soft x-ray tomography to image the 3-D structure of both benign and infectious C. albicans yeast. They then imaged this yeast when treated with peptoids, a class of molecules that mimic the peptides our immune system uses as the first line of defense against microbial attack. Unlike conventional antimicrobials, microbes have yet to develop resistance mechanisms against peptides or peptoids, making them appealing candidates for pharmaceutical development.

219

High-resolution ab initio three-dimensional X-ray diffraction microscopy  

DOE Data Explorer (OSTI)

The file contains 125 images corresponding to different tilts of the sample around the y axis at 1 degree intervals. Each image is the result of 4 exposures merged together. For more details see the citation.

Chapman, Henry N.

220

Development of a portable x-ray computed tomographic imaging system for drill-site investigation of recovered core  

SciTech Connect

A portable x-ray computed tomography (CT) system was constructed for imaging core at drill sites. Performing drill-site-based x-ray scanning and CT analysis permits rapid evaluation of core properties (such as density, lithologic structure, and macroporosity distribution) and allows for real-time decision making for additional core-handling procedures. Because of the speed with which scanning is performed, systematic imaging and electronic cataloging of all retrieved core is feasible. Innovations (such as a novel clamshell shielding arrangement integrated with system interlocks) permit safe operation of the x-ray system in a busy core handling area. The minimization of the volume encapsulated with shielding reduces the overall system weight and facilitates instrument portability. The x-ray system as originally fabricated had a 110 kV x-ray source with a fixed 300-micron focal spot size. A 15 cm image intensifier with a cesium iodide phosphor input screen was coupled to a CCD for image capture. The CT system has since been modified with a 130 kV micro-focal x-ray source. With the x-ray system's variable focal spot size, high-resolution studies (10-micron resolution) can be performed on core plugs and coarser (100-micron resolution) images can be acquired of whole drill cores. The development of an aluminum compensator has significantly improved the dynamic range and accuracy of the system. An x-ray filter has also been incorporated, permitting rapid acquisition of multi-energy scans for more quantitative analysis of sample mineralogy. The x-ray CT system has operated reliably under extreme field conditions, which have varied from shipboard to arctic.

Freifeld, Barry M.; Kneafsey, Timothy J.; Tomutsa, Liviu; Pruess, Jacob

2003-05-01T23:59:59.000Z

Note: This page contains sample records for the topic "x-ray diffraction imaging" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


221

Detection sensitivity of x-ray CT imaging for NDE of green-state ceramics  

DOE Green Energy (OSTI)

Improved ceramic-processing methods that use pressure slip-casting and injection molding are being developed at Norton Advanced Ceramics, with a goal of producing reliable structural ceramics for advanced heat engines. Nondestructive evaluation (NDE) of ceramic parts at different stages of processing can provide useful diagnostic information to help improve processing techniques. For example, an evaluation of density gradients in as-cast green-body samples can be used to judge mold performance and make changes in mold design. Also, the ability to detect minute flaws (20 to 50 {mu}m), such as agglomerates, inclusions, and voids, in green-body, presintered, and densified parts is important in ensuring structural reliability of the final parts, because these flaws, above certain critical sizes, can lead to catastrophic failure. Three-dimensional microfocus X-ray computed tomography (CT) and nuclear magnetic resonance imaging (MRI) systems have been developed at Argonne National Laboratory (ANL) for application to quantitative NDE evaluation of ceramics. This paper evaluates the detection sensitivity of the ANL X-ray CT system when used to determine density gradients, inclusions, and voids in green-state Si{sub 3}N{sub 4} ceramics. A theoretical account of key system- and sample-related parameters affecting X-ray CT detection sensitivity is given, and results of experimental evaluation are presented. Density calibration phantoms and net-shape-formed tensile rods with seeded defects were used in the experimental evaluation of detection limits. 6 refs., 6 figs., 1 tab.

Gopalsami, N.; Rizo, P.; Ellingson, W.A. (Argonne National Lab., IL (United States)); Tracey, D.M. (Norton Co., Northboro, MA (United States). Advanced Ceramics Div.)

1991-01-01T23:59:59.000Z

222

Imaging Antifungal Drug Molecules in Action using Soft X-Ray Tomography  

NLE Websites -- All DOE Office Websites (Extended Search)

Imaging Antifungal Drug Molecules in Action using Soft X-Ray Tomography Print Imaging Antifungal Drug Molecules in Action using Soft X-Ray Tomography Print Humankind has benefitted from a long and productive relationship with yeast. For example, fermentation by yeast is an essential step in the production of bread, beer, wine, and even biofuels. However, not all yeast are beneficial. One strain of yeast, Candida albicans, grows unnoticed on most peoples' skin and in the intestines. In response to certain environmental conditions, C. albicans can switch to a pathogenic phenotype that causes infection. Yeast infections are commonplace, and in otherwise healthy individuals are usually treatable with over-the-counter medications; however, individuals with weakened immune systems can have very serious systemic consequences from a yeast infection. Treating systemic yeast infections is becoming increasingly difficult due to the growing number of yeast strains that have developed resistance to existing antimicrobial drugs. Consequently, there is a pressing need to develop new types of drugs capable of circumventing yeast drug-resistance mechanisms. To this end Stanford, University of California, San Francisco and LBNL researchers have used soft x-ray tomography to image the 3-D structure of both benign and infectious C. albicans yeast. They then imaged this yeast when treated with peptoids, a class of molecules that mimic the peptides our immune system uses as the first line of defense against microbial attack. Unlike conventional antimicrobials, microbes have yet to develop resistance mechanisms against peptides or peptoids, making them appealing candidates for pharmaceutical development.

223

Imaging Antifungal Drug Molecules in Action using Soft X-Ray Tomography  

NLE Websites -- All DOE Office Websites (Extended Search)

Imaging Antifungal Drug Molecules in Action using Soft X-Ray Tomography Print Imaging Antifungal Drug Molecules in Action using Soft X-Ray Tomography Print Humankind has benefitted from a long and productive relationship with yeast. For example, fermentation by yeast is an essential step in the production of bread, beer, wine, and even biofuels. However, not all yeast are beneficial. One strain of yeast, Candida albicans, grows unnoticed on most peoples' skin and in the intestines. In response to certain environmental conditions, C. albicans can switch to a pathogenic phenotype that causes infection. Yeast infections are commonplace, and in otherwise healthy individuals are usually treatable with over-the-counter medications; however, individuals with weakened immune systems can have very serious systemic consequences from a yeast infection. Treating systemic yeast infections is becoming increasingly difficult due to the growing number of yeast strains that have developed resistance to existing antimicrobial drugs. Consequently, there is a pressing need to develop new types of drugs capable of circumventing yeast drug-resistance mechanisms. To this end Stanford, University of California, San Francisco and LBNL researchers have used soft x-ray tomography to image the 3-D structure of both benign and infectious C. albicans yeast. They then imaged this yeast when treated with peptoids, a class of molecules that mimic the peptides our immune system uses as the first line of defense against microbial attack. Unlike conventional antimicrobials, microbes have yet to develop resistance mechanisms against peptides or peptoids, making them appealing candidates for pharmaceutical development.

224

Imaging Antifungal Drug Molecules in Action using Soft X-Ray Tomography  

NLE Websites -- All DOE Office Websites (Extended Search)

Imaging Antifungal Drug Molecules in Action using Soft X-Ray Tomography Print Imaging Antifungal Drug Molecules in Action using Soft X-Ray Tomography Print Humankind has benefitted from a long and productive relationship with yeast. For example, fermentation by yeast is an essential step in the production of bread, beer, wine, and even biofuels. However, not all yeast are beneficial. One strain of yeast, Candida albicans, grows unnoticed on most peoples' skin and in the intestines. In response to certain environmental conditions, C. albicans can switch to a pathogenic phenotype that causes infection. Yeast infections are commonplace, and in otherwise healthy individuals are usually treatable with over-the-counter medications; however, individuals with weakened immune systems can have very serious systemic consequences from a yeast infection. Treating systemic yeast infections is becoming increasingly difficult due to the growing number of yeast strains that have developed resistance to existing antimicrobial drugs. Consequently, there is a pressing need to develop new types of drugs capable of circumventing yeast drug-resistance mechanisms. To this end Stanford, University of California, San Francisco and LBNL researchers have used soft x-ray tomography to image the 3-D structure of both benign and infectious C. albicans yeast. They then imaged this yeast when treated with peptoids, a class of molecules that mimic the peptides our immune system uses as the first line of defense against microbial attack. Unlike conventional antimicrobials, microbes have yet to develop resistance mechanisms against peptides or peptoids, making them appealing candidates for pharmaceutical development.

225

Imaging Antifungal Drug Molecules in Action using Soft X-Ray Tomography  

NLE Websites -- All DOE Office Websites (Extended Search)

Imaging Antifungal Drug Molecules in Action using Soft X-Ray Tomography Print Imaging Antifungal Drug Molecules in Action using Soft X-Ray Tomography Print Humankind has benefitted from a long and productive relationship with yeast. For example, fermentation by yeast is an essential step in the production of bread, beer, wine, and even biofuels. However, not all yeast are beneficial. One strain of yeast, Candida albicans, grows unnoticed on most peoples' skin and in the intestines. In response to certain environmental conditions, C. albicans can switch to a pathogenic phenotype that causes infection. Yeast infections are commonplace, and in otherwise healthy individuals are usually treatable with over-the-counter medications; however, individuals with weakened immune systems can have very serious systemic consequences from a yeast infection. Treating systemic yeast infections is becoming increasingly difficult due to the growing number of yeast strains that have developed resistance to existing antimicrobial drugs. Consequently, there is a pressing need to develop new types of drugs capable of circumventing yeast drug-resistance mechanisms. To this end Stanford, University of California, San Francisco and LBNL researchers have used soft x-ray tomography to image the 3-D structure of both benign and infectious C. albicans yeast. They then imaged this yeast when treated with peptoids, a class of molecules that mimic the peptides our immune system uses as the first line of defense against microbial attack. Unlike conventional antimicrobials, microbes have yet to develop resistance mechanisms against peptides or peptoids, making them appealing candidates for pharmaceutical development.

226

Imaging Antifungal Drug Molecules in Action using Soft X-Ray Tomography  

NLE Websites -- All DOE Office Websites (Extended Search)

Imaging Antifungal Drug Molecules in Action using Soft X-Ray Tomography Print Imaging Antifungal Drug Molecules in Action using Soft X-Ray Tomography Print Humankind has benefitted from a long and productive relationship with yeast. For example, fermentation by yeast is an essential step in the production of bread, beer, wine, and even biofuels. However, not all yeast are beneficial. One strain of yeast, Candida albicans, grows unnoticed on most peoples' skin and in the intestines. In response to certain environmental conditions, C. albicans can switch to a pathogenic phenotype that causes infection. Yeast infections are commonplace, and in otherwise healthy individuals are usually treatable with over-the-counter medications; however, individuals with weakened immune systems can have very serious systemic consequences from a yeast infection. Treating systemic yeast infections is becoming increasingly difficult due to the growing number of yeast strains that have developed resistance to existing antimicrobial drugs. Consequently, there is a pressing need to develop new types of drugs capable of circumventing yeast drug-resistance mechanisms. To this end Stanford, University of California, San Francisco and LBNL researchers have used soft x-ray tomography to image the 3-D structure of both benign and infectious C. albicans yeast. They then imaged this yeast when treated with peptoids, a class of molecules that mimic the peptides our immune system uses as the first line of defense against microbial attack. Unlike conventional antimicrobials, microbes have yet to develop resistance mechanisms against peptides or peptoids, making them appealing candidates for pharmaceutical development.

227

Microsoft PowerPoint - X-rayScatteringDiffraction_X27C.ppt [Compatibil...  

NLE Websites -- All DOE Office Websites (Extended Search)

Molecular Biology Laboratory) detectors. 2-D area detector: Imaging plate (Fuji BAS 2500); MAR CCD. The availability of various samples chambers (listed on htt b l l...

228

Multipixel characterization of imaging CZT detectors for hard X-ray imaging and spectroscopy  

E-Print Network (OSTI)

We report our in-depth study of Cd-Zn-Te (CZT) crystals to determine an optimum pixel and guard band configuration for Hard X-ray imaging and spectroscopy. We tested 20x20x5mm crystals with 8x8 pixels on a 2.46mm pitch. We have studied different types of cathode / anode contacts and different pixel pad sizes. We present the measurements of leakage current as well as spectral response for each pixel. Our I-V measurement setup is custom designed to allow automated measurements of the I-V curves sequentially for all 64 pixels, whereas the radiation properties measurement setup allows for interchangeable crystals with the same XAIM3.2 ASIC readout from IDEAS. We have tested multiple crystals of each type, and each crystal in different positions to measure the variation between individual crystals and variation among the ASIC channels. We also compare the same crystals with and without a grounded guard band deposited on the crystal side walls vs. a floating guard band and compare results to simulations. This study was carried out to find the optimum CZT crystal configuration for prototype detectors for the proposed Black-Hole Finder mission, EXIST.

S. V. Vadawale; J. Hong; J. Grindlay; P. Williams; M. Zhang; E. Bellm; T. Narita; W. Craig; B. Parker; C. Stahle; Feng Yan

2004-09-03T23:59:59.000Z

229

Optical and x-ray imaging of electron beams using synchrotron emission  

SciTech Connect

In the case of very low eniittance electron and positron storage ring beams, it is impossible to make intrusive measurements of beam properties without increasing the emittance and possibly disrupting the beam. In cases where electron or positron beams have high average power densities (such as free electron laser linacs), intrusive probes such as wires and optical transition radiation screens or Cherenkov emitting screens can be easily damaged or destroyed. The optical and x-ray emissions from the bends in the storage rings and often from linac bending magnets can be used to image the beam profile to obtain emittance information about the beam. The techniques, advantages and limitations of using both optical and x-ray synchrotron emission to measure beam properties are discussed and the possibility of single bunch imaging is considered. The properties of suitable imagers and converters such as phosphors are described. Examples of previous, existing and planned applications are given where available, including a pinhole imaging system currently being designed for the Advanced Photon Source at Argonne National Laboratory.

Wilke, M.D.

1994-12-01T23:59:59.000Z

230

THE CRYSTAL STRUCTURE OF THORIUM AND ZIRCONIUM DIHYDRIDES BY X-RAY AND NEUTRON DIFFRACTION  

DOE Green Energy (OSTI)

Thorium forms a tetragonal lower hydride of composition ThH{sub 2}. The hydrides ThH{sub 2}, ThD{sub 2} and ZrD{sub 2} have been studied by neutron diffraction in order that hydrogen positions could be determined. The hydrides are isomorphous, and have a deformed fluorite structure. Metal-hydrogen distances in thorium hydride are unusually large, as in UH{sub 3}. Thorium and zirconium scattering amplitudes and a revised scattering amplitude for deuterium are reported.

Rundle, R.E.; Shull, C.G.; Wollan, E.O.

1951-04-20T23:59:59.000Z

231

A monochromatic x-ray imaging system for characterizing low-density foams  

SciTech Connect

In High Energy Density (HED) laser experiments, targets often require small, low-density, foam components. However, their limited size can preclude single component characterization, forcing one to rely solely on less accurate bulk measurements. We have developed a monochromatic imaging a system to characterize both the density and uniformity of single component low-mass foams. This x-ray assembly is capable of determining line-averaged density variations near the 1% level, and provides statistically identical results to those obtained at the Brookhaven's NSLS. This system has the added benefit of providing two-dimensional density data, allowing an assessment of density uniformity.

Lanier, Nicholas E. [Los Alamos National Laboratory; Taccetti, Jose M. [Los Alamos National Laboratory; Hamilton, Christopher E. [Los Alamos National Laboratory

2012-05-04T23:59:59.000Z

232

Resonant X-Ray Diffraction Study of an Unusually Large Phase Coexistance in Smectic Liquid-Crystal Films  

Science Conference Proceedings (OSTI)

The recent discovery of the new smectic-C{sub d6}* (SmC{sub d6}*) phase [S. Wang et al. Phys. Rev. Lett. 104 027801 (2010)] also revealed the existence of a noisy region in the temperature window between the SmC{sub d6}* phase and the smectic-C{sub d4}* (SmC{sub d4}*) phase. Characterized by multiple resonant peaks spanning a wide region in Q{sub Z}, the corresponding structure of this temperature window has been a mystery. In this Letter, through a careful resonant x-ray diffraction study and simulations of the diffraction spectra, we show that this region is in fact an unusually large coexistence region of the SmC{sub d6}* phase and the SmC{sub d4}* phase. The structure of the noisy region is found to be a heterogeneous mixture of local SmC{sub d6}* and SmC{sub d4}* orders on the sub-{micro}m scale.

Pan L.; Pindak R.; Barois, P.; Liu, Z.Q.; McCoy, B.K. & Hyang, C.C.

2012-01-19T23:59:59.000Z

233

A scaled gradient projection method for the X-ray imaging of solar flares  

E-Print Network (OSTI)

In this paper we present a new optimization algorithm for the reconstruction of X-ray images of solar flares by means of the data collected by the Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI). The imaging concept of the satellite is based of rotating modulation collimator instruments, which allow the use of both Fourier imaging approaches and reconstruction techniques based on the straightforward inversion of the modulated count profiles. Although in the last decade a greater attention has been devoted to the former strategies due to their very limited computational cost, here we consider the latter model and investigate the effectiveness of a scaled gradient projection method for the solution of the corresponding constrained minimization problem. Moreover, regularization is introduced through either an early stopping of the iterative procedure, or a Tikhonov term added to the discrepancy function, by means of a discrepancy principle accounting for the Poisson nature of the noise affecting th...

Bonettini, S

2013-01-01T23:59:59.000Z

234

Epp: A C++ EGSnrc user code for x-ray imaging and scattering simulations  

Science Conference Proceedings (OSTI)

Purpose: Easy particle propagation (Epp) is a user code for the EGSnrc code package based on the C++ class library egspp. A main feature of egspp (and Epp) is the ability to use analytical objects to construct simulation geometries. The authors developed Epp to facilitate the simulation of x-ray imaging geometries, especially in the case of scatter studies. While direct use of egspp requires knowledge of C++, Epp requires no programming experience. Methods: Epp's features include calculation of dose deposited in a voxelized phantom and photon propagation to a user-defined imaging plane. Projection images of primary, single Rayleigh scattered, single Compton scattered, and multiple scattered photons may be generated. Epp input files can be nested, allowing for the construction of complex simulation geometries from more basic components. To demonstrate the imaging features of Epp, the authors simulate 38 keV x rays from a point source propagating through a water cylinder 12 cm in diameter, using both analytical and voxelized representations of the cylinder. The simulation generates projection images of primary and scattered photons at a user-defined imaging plane. The authors also simulate dose scoring in the voxelized version of the phantom in both Epp and DOSXYZnrc and examine the accuracy of Epp using the Kawrakow-Fippel test. Results: The results of the imaging simulations with Epp using voxelized and analytical descriptions of the water cylinder agree within 1%. The results of the Kawrakow-Fippel test suggest good agreement between Epp and DOSXYZnrc. Conclusions: Epp provides the user with useful features, including the ability to build complex geometries from simpler ones and the ability to generate images of scattered and primary photons. There is no inherent computational time saving arising from Epp, except for those arising from egspp's ability to use analytical representations of simulation geometries. Epp agrees with DOSXYZnrc in dose calculation, since they are both based on the well-validated standard EGSnrc radiation transport physics model.

Lippuner, Jonas; Elbakri, Idris A.; Cui Congwu; Ingleby, Harry R. [Department of Medical Physics, CancerCare Manitoba, 675 McDermot Avenue, Winnipeg, Manitoba R3E 0V9 (Canada) and Department of Physics and Astronomy, University of Manitoba, Winnipeg, Manitoba R3T 2N2 (Canada); Department of Medical Physics, CancerCare Manitoba, 675 McDermot Avenue, Winnipeg, Manitoba R3E 0V9 (Canada); Department of Physics and Astronomy, University of Manitoba, Winnipeg, Manitoba R3T 2N2 (Canada) and Department of Radiology, University of Manitoba, 820 Sherbrook Street, Winnipeg, Manitoba R3A 1R9 (Canada); Department of Medical Physics, CancerCare Manitoba, 675 McDermot Avenue, Winnipeg, Manitoba R3E 0V9 (Canada)

2011-03-15T23:59:59.000Z

235

Pulsed X-ray Characterization of Stripline Micro-Channel Plate Gated Imager  

Science Conference Proceedings (OSTI)

We report on characterization of x-ray imaging arrays developed by National Security Technologies, LLC. These devices are based on a microchannel plate (MCP) with a conventional glass microchannel structure, but the top and bottom conductive coatings, rather than covering the entire area, are configured into several (4 to 8) parallel strips. Since the bias voltage is a pulse launched from one end, these operate as striplines; relative delays between these pulses give different active exposure times. Unlike the case of a static bias voltage, non-uniformities in impedance along a stripline will produce spatial fluctuations in the bias voltage. These are expected to be slight, but the very sensitive dependence of gain on voltage - approximately like Vl/4d, where l and d are the length and diameter of the channel - means there may be very significant spatial non-uniformities in gain. Flat-field calibrations are therefore required so that such effects can be unfolded from the raw images if quantitative data is required. Such flat-field and other characterization measurements, e.g. responsivity and linearity, have therefore been done with a flash X-ray radiographic system. The maximum endpoint energy is 500 keV. The duration is {approx}40 ns, and so is essentially flat (temporally) during the MCP stripline transit time, which is a maximum of 600 ps. Spatial variations are significant, but the data are corrected using independent flat-field measurements. A monochromator selects a particular X-ray transition line (typically K{alpha}) of the anode material, so that characterizations can be done for various well-defined input photon energies.

F. J. Goldin, D. V. Morgan, K. J. Moy

2011-03-30T23:59:59.000Z

236

Synchrotron X-ray diffraction studies of phase transitions and mechanical properties of nanocrystalline materials at high pressure  

Science Conference Proceedings (OSTI)

The behavior of nanocrystals under extreme pressure was investigated using synchrotron x-ray diffraction. A major part of this investigation was the testing of a prototype synchrotron endstation on a bend magnet beamline at the Advanced Light Source for high pressure work using a diamond anvil cell. The experiments conducted and documented here helped to determine issues of efficiency and accuracy that had to be resolved before the construction of a dedicated ''super-bend'' beamline and endstation. The major conclusions were the need for a cryo-cooled monochromator and a fully remote-controllable pressurization system which would decrease the time to change pressure and greatly reduce the error created by the re-placement of the diamond anvil cell after each pressure change. Two very different types of nanocrystal systems were studied, colloidal iron oxide (Fe{sub 2}O{sub 3}) and thin film TiN/BN. Iron oxide nanocrystals were found to have a transition from the {gamma} to the {alpha} structure at a pressure strongly dependent on the size of the nanocrystals, ranging from 26 GPa for 7.2 nm nanocrystals to 37 GPa for 3.6 nm nanocrystals. All nanocrystals were found to remain in the {alpha} structure even after release of pressure. The transition pressure was also found, for a constant size (5.7 nm) to be strongly dependent on the degree of aggregation of the nanocrystals, increasing from 30 GPa for completely dissolved nanocrystals to 45 GPa for strongly aggregated nanocrystals. Furthermore, the x-ray diffraction pattern of the pressure induced {alpha} phase demonstrated a decrease in intensity for certain select peaks. Together, these observations were used to make a complete picture of the phase transition in nanocrystalline systems. The size dependence of the transition was interpreted as resulting from the extremely high surface energy of the {alpha} phase which would increase the thermodynamic offset and thereby increase the kinetic barrier to transition that must be overridden with pressure. The anomalous intensities in the x-ray diffraction patterns were interpreted as being the result of stacking faults, indicating that the mechanism of transition proceeds by the sliding of {gamma}(111) planes to form {alpha}(001) planes. The increasing transition pressure for more aggregated samples may be due to a positive activation volume, retarding the transition for nanocrystals with less excess (organic) volume available to them. The lack of a reverse transition upon decompression makes this interpretation more difficult because of the lack of an observable hysteresis, and it is therefore difficult to ascertain kinetic effects for certain. In the case TiN/BN nanocomposite systems, it was found that the bulk modulus (B{sub 0}) of the TiN nanoparticles was not correlated to the observed hardness or Young's modulus of the macroscopic thin film. This indicates that the origin of the observed super-hard nature of these materials is not due to any change in the Ti-N interatomic potential. Rather, the enhanced hardness must be due to nano-structural effects. It was also found that during pressurization the TiN nanoparticles developed a great deal of strain. This strain can be related to defects induced in individual nanoparticles which generates strain in adjacent particles due to the highly coupled nature of the system.

Prilliman, Gerald Stephen

2003-09-01T23:59:59.000Z

237

Beyond 3-D X-ray Imaging: Methodology Development and Applications...  

NLE Websites -- All DOE Office Websites (Extended Search)

few decades. The most substantial advancements in this field are closely related to the availability of the new generation of X-ray sources and the advanced X-ray optics. The...

238

A Fern Fatale - X-ray Absorption Spectroscopy Imaging an Arsenic-Loving  

NLE Websites -- All DOE Office Websites (Extended Search)

Fern Fatale - X-ray Absorption Spectroscopy Imaging of an Arsenic-Loving Fern Fatale - X-ray Absorption Spectroscopy Imaging of an Arsenic-Loving Fern For many people, arsenic is synonymous with poison, so it is perhaps a surprise that some plants, such as the fern Pteris vittata (Figure 1) seem to quite deliberately accumulate large amounts of it. What is more, the plant converts it to the most toxic inorganic form known. How does it do this? First some background; while there is some evidence that arsenic is required for health [1], this is debatable. On the other hand, the poisonous nature of arsenic compounds was understood by the ancient Greeks and Romans, and it has been used throughout history as a homicidal and suicidal agent. It is found in two environmentally common oxy acids; arsenous acid (H3AsO3), and arsenic acid (H3AsO4), whose salts are known as arsenites and arsenates, respectively. Of these, the trivalent arsenic species are the most toxic. The infamous agent of murder is arsenic trioxide (white arsenic or As2O3), which is simply the (reputedly tasteless) anhydride of arsenous acid.

239

Science with Micro-X: the TES Microcalorimeter X-ray Imaging Rocket  

DOE Green Energy (OSTI)

Micro-X is a proposed sounding rocket experiment that will combine a transition-edge-sensor X-ray-microcalorimeter array with a conical imaging mirror to obtain high-spectral-resolution images of extended and point X-ray sources. We describe the payload and the science targeted by this mission including the discussion of three possible Micro-X targets: the Puppis A supernova remnant, the Virgo Cluster, and Circinus X-1. For example, a Micro-X observation of the bright eastern knot of Puppis A will obtain a line-dominated spectrum with 90,000 counts collected in 300 seconds at 2 eV resolution across the 0.3-2.5 keV band. Micro-X will utilize plasma diagnostics to determine the thermodynamic and ionization state of the plasma, to search for line shifts and broadening associated with dynamical processes, and seek evidence of ejecta enhancement. For clusters of galaxies, Micro-X can uniquely study turbulence and the temperature distribution function. For binaries, Micro-X's high resolution spectra will separate the different processes contributing to the Fe K lines at 6 keV and give a clear view of the geometry of the gas flows and circumstellar gas.

Figueroa-Feliciano, E; Bandler, S R; Bautz, M; Boyce, K R; Brown, G V; Deiker, S; Doriese, W B; Flanagan, K; Galeazzi, M; Hilton, G C; Hwang, U; Irwin, K D; Kallman, T; Kelley, R L; Kilbourne, C A; Kissel, S; Levine, A; Loewenstein, M; Martinez-Galarce, D; McCammon, D; Mushotzky, R; Petre, R; Porter, F S; Reistema, C D; Saab, T; Serlemitsos, P; Schulz, N; Smith, R; Ullom, J N

2006-05-16T23:59:59.000Z

240

A Comparison of Image Quality Evaluation Techniques for Transmission X-Ray Microscopy  

SciTech Connect

Beamline 6-2c at Stanford Synchrotron Radiation Lightsource (SSRL) is capable of Transmission X-ray Microscopy (TXM) at 30 nm resolution. Raw images from the microscope must undergo extensive image processing before publication. Since typical data sets normally contain thousands of images, it is necessary to automate the image processing workflow as much as possible, particularly for the aligning and averaging of similar images. Currently we align images using the 'phase correlation' algorithm, which calculates the relative offset of two images by multiplying them in the frequency domain. For images containing high frequency noise, this algorithm will align noise with noise, resulting in a blurry average. To remedy this we multiply the images by a Gaussian function in the frequency domain, so that the algorithm ignores the high frequency noise while properly aligning the features of interest (FOI). The shape of the Gaussian is manually tuned by the user until the resulting average image is sharpest. To automatically optimize this process, it is necessary for the computer to evaluate the quality of the average image by quantifying its sharpness. In our research we explored two image sharpness metrics, the variance method and the frequency threshold method. The variance method uses the variance of the image as an indicator of sharpness while the frequency threshold method sums up the power in a specific frequency band. These metrics were tested on a variety of test images, containing both real and artificial noise. To apply these sharpness metrics, we designed and built a MATLAB graphical user interface (GUI) called 'Blur Master.' We found that it is possible for blurry images to have a large variance if they contain high amounts of noise. On the other hand, we found the frequency method to be quite reliable, although it is necessary to manually choose suitable limits for the frequency band. Further research must be performed to design an algorithm which automatically selects these parameters.

Bolgert, Peter J; /Marquette U. /SLAC

2012-08-31T23:59:59.000Z

Note: This page contains sample records for the topic "x-ray diffraction imaging" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


241

Pressure and field tuning the magnetostructural phases of Mn3O4: Raman scattering and x-ray diffraction studies  

Science Conference Proceedings (OSTI)

We present temperature-, magnetic-field-, and pressure-dependent Raman scattering studies of single crystal Mn{sub 3}O{sub 4}, combined with temperature- and field-dependent x-ray diffraction studies, revealing the novel magnetostructural phases in Mn{sub 3}O{sub 4}. Our temperature-dependent studies showed that the commensurate magnetic transition at T{sub 2} = 33K in the binary spinel Mn{sub 3}O{sub 4} is associated with a structural transition from tetragonal to orthorhombic structures. Field-dependent studies showed that the onset and nature of this structural transition can be controlled with an applied magnetic field, and revealed evidence for a field-tuned quantum phase transition to a tetragonal spin-disordered phase for H {parallel} [1{bar 1}0]. Pressure-dependent Raman measurements showed that the magnetic easy axis direction in Mn{sub 3}O{sub 4} can be controlled - and the ferrimagnetic transition temperature increased - with applied pressure. Finally, combined pressure- and magnetic-field-tuned Raman measurements revealed a rich magnetostructural phase diagram - including a pressure- and field-induced magnetically frustrated tetragonal phase in the PH phase diagram - that can be generated in Mn{sub 3}O{sub 4} with applied pressure and magnetic field.

Kim, M.; Nelson, C.; Chen, X.M.; Wang, X.; Budakian, R.; Abbamonte, P. & Cooper, S.L.

2011-11-18T23:59:59.000Z

242

Study of Antisite Defects in Hydrothermally Prepared LiFePO4 by in Situ X-ray Diffraction  

Science Conference Proceedings (OSTI)

Hydrothermal synthesis has proven to be a cost-effective, energy-efficient approach for the manufacture of lithium iron phosphate (LiFePO{sub 4}) and its related materials. However, hydrothermally prepared LiFePO{sub 4} typically suffers from antisite defects, where some of the iron resides on lithium sites and restricts lithium-ion mobility. A post-heat-treatment temperature of around 700 C is generally used to eliminate cation disorder, but little is known about these antisite defects or their concentration as a function of the post-heat-treatment temperature. In this study, time-resolved, synchrotron X-ray diffraction reveals that antisite defects are completely eliminated above 500 C, suggesting that the electrochemical performance may be significantly enhanced by a milder postsynthesis heat treatment. The preliminary electrochemical results show a significant enhancement in the electrochemical capacity with the defect-free material, with the specific capacity increasing by approximately 60% at a C/20 rate.

J Chen; J Graetz

2011-12-31T23:59:59.000Z

243

Advanced Techniques for In-Situ Monitoring of Phase Transformations During Welding Using Synchrotron-Based X-Ray Diffraction  

SciTech Connect

Understanding the evolution of microstructure in welds is an important goal of welding research because of the strong correlation between weld microstructure and weld properties. To achieve this goal it is important to develop a quantitative measure of phase transformations encountered during welding in order to ultimately develop methods for predicting weld microstructures from the characteristics of the welding process. To aid in this effort, synchrotron radiation methods have been developed at Lawrence Livermore National Laboratory (LLNL) for direct observation of microstructure evolution during welding. Using intense, highly collimated synchrotron radiation, the atomic structure of the weld heat affected and fusion zones can be probed in real time. Two synchrotron-based techniques, known as spatially resolved (SRXRD) and time resolved (TRXRD) x-ray diffraction, have been developed for these investigations. These techniques have now been used to investigate welding induced phase transformations in titanium alloys, low alloy steels, and stainless steel alloys. This paper will provide a brief overview of these methods and will discuss microstructural evolution during the welding of low carbon (AISI 1005) and medium carbon (AISI 1045) steels where the different levels of carbon influence the evolution of microstructures during welding.

Elmer, J W; Palmer, T A; Zhang, W; DebRoy, T

2005-06-05T23:59:59.000Z

244

Ferrocyanide Safety Project Dynamic X-Ray Diffraction studies of sodium nickel ferrocyanide reactions with equimolar nitrate/nitrite salts  

Science Conference Proceedings (OSTI)

Dynamic X-ray Diffraction (DXRD) has been to used to identify and quantify the solid state reactions that take place between sodium nickel ferrocyanide, Na{sub 2}NiFe(CN){sub 6}, and equimolar concentrations of sodium nitrate/nitrite, reactions of interest to the continued environmental safety of several large underground waste storage tanks at the Hanford site in eastern Washington. The results are supportive of previous work, which indicated that endothermic dehydration and melting of the nitrates take place before the occurrence of exothermic reactions that being about 300{degrees}C. The DXRD results show that a major reaction set at these temperatures is the occurrence of a series reaction that produces sodium cyanate, NaCNO, as an intermediate in a mildly exothermic first step. In the presence of gaseous oxygen, NaCNO subsequently reacts exothermally and at a faster rate to form metal oxides. Measurements of the rate of this reaction are used to estimate the heat release. Comparisons of this estimated heat release rate with heat transfer rates from a hypothetical ``hot spot`` show that, even in a worst-case scenario, the heat transfer rates are approximately eight times higher than the rate of energy release from the exothermic reactions.

Dodds, J.N. [Washington State Univ., Pullman, WA (United States). Dept. of Chemical Engineering]|[UNOCAL, Brea, CA (United States). Hartley Research Center

1994-07-01T23:59:59.000Z

245

Humidity-controlled preparation of frozen-hydrated biological samples for cryogenic coherent x-ray diffraction microscopy  

Science Conference Proceedings (OSTI)

Coherent x-ray diffraction microscopy (CXDM) has the potential to visualize the structures of micro- to sub-micrometer-sized biological particles, such as cells and organelles, at high resolution. Toward advancing structural studies on the functional states of such particles, here, we developed a system for the preparation of frozen-hydrated biological samples for cryogenic CXDM experiments. The system, which comprised a moist air generator, microscope, micro-injector mounted on a micromanipulator, custom-made sample preparation chamber, and flash-cooling device, allowed for the manipulation of sample particles in the relative humidity range of 20%-94%rh at 293 K to maintain their hydrated and functional states. Here, we report the details of the system and the operation procedure, including its application to the preparation of a frozen-hydrated chloroplast sample. Sample quality was evaluated through a cryogenic CXDM experiment conducted at BL29XUL of SPring-8. Taking the performance of the system and the quality of the sample, the system was suitable to prepare frozen-hydrated biological samples for cryogenic CXDM experiments.

Takayama, Yuki; Nakasako, Masayoshi [Department of Physics, Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Kanagawa 223-8522 (Japan); RIKEN Harima Institute/SPring-8, 1-1-1 Kouto, Mikaduki, Sayo, Hyogo 679-5148 (Japan)

2012-05-15T23:59:59.000Z

246

In-situ x-ray diffraction of layered LiCoO{sub 2}-Type cathode materials  

DOE Green Energy (OSTI)

The authors have investigated LiNi{sub 0.8}Co{sub 0.2}O{sub 2} (Sumitomo) and LiNi{sub 5/8}Co{sub 1/4}Mn{sub 1/16}Al{sub 1/16}O{sub 2} (Sandia chemical preparation method) cathode powders via in-situ X-ray Diffraction and Cyclic Voltammetry using a coffee-bag type electrochemical cell. Both cathode materials did not show a monoclinic distortion during de-intercalation but sustained the hexagonal structure up to 4.3 V. The doping of Co into the LiNiO{sub 2} structure appears to stabilize this lattice as the hexagonal structure over the full range of charging (up to 4.3 V). The LiNi{sub 5/8}Co{sub 1/4}Mn{sub 1/16}Al{sub 1/16}O{sub 2} cathode material exhibited a 160 mAh/g capacity (to 4.1 V) on its 1{sup st} cycle, while displaying a much smaller volume change (as compared to LiNi{sub 0.8}Co{sub 0.2}O{sub 2}) during de-intercalation. This reduced overall volume change (2.5 vol%) may have important implications for cycle life of this material.

Rodriguez, M.A.; Ingersoll, D.; Doughty, D.H.

1999-12-09T23:59:59.000Z

247

Pore and throat size distributions measured from synchrotron X-ray tomographic images of Fontainebleau sandstones  

E-Print Network (OSTI)

The three-dimensional geometry and connectivity of pore space controls the hydraulic transport behavior of crustal rocks. We report on direct measurement of flow-relevant geometrical properties of the void space in a suite of 4 samples of Fontainebleau sandstone ranging from 7.5% to 22% porosity. The measurements are obtained from computer analysis of three dimensional, synchrotron X-ray computed microtomographic images. We present measured distributions of coordination number, channel length, throat size and pore volume, and of correlations between throat-size/pore-volume and nearest neighbor pore-volume/pore volume determined for these samples. We also present quantitative characterization of the distributions measured. The effects of finite sample volume are investigated. The accuracy of the numerical algorithms employed is investigated using a simulated image of hexagonal closed packed spheres.

W. Brent Lindquist; Arun Venkatarangan; John Dunsmuir; Teng-fong Wong

1999-01-01T23:59:59.000Z

248

Time Integrated Soft X-ray Imaging in High Intensity Laser Experiments (thesis)  

Science Conference Proceedings (OSTI)

2009 marks a significant achievement and the dawn of a new era in high intensity laser research with the final commissioning of all 192 beams at the National Ignition Facility (NIF). NIF is a department of energy (DOE) funded project more than 10 years in the making located at the Lawrence Livermore National Laboratory (LLNL). The following research was done as one of many preliminary experiments done to prepare for these historic events. The primary focus of the experimental campaign this paper addresses is to test and develop a thermal x-radiation source using a short pulse laser. This data is hoped to provide information about the thermal transport mechanisms important in the development of prediction models in High Energy Density (HED) science. One of several diagnostics fielded was a soft x-ray imager (SXRI) which is detailed in this paper. The SXRI will be used to measure the relative size of the heated region and also the relative level of specific x-ray emissions among several shot and target configurations. The laser system used was the Titan laser located in the Jupiter Laser Facility (JLF) at Lawrence Livermore National Laboratory (LLNL). Titan uses the JLF Janus Nd:glass laser west frontend system with a Optical Parametric Chirped Pulse Amplification (OPCPA) in place of the nanosecond oscillator. The system is capable of producing laser intensities of over a petawatt with several tens of joules delivered in the beam.

Stafford, D

2009-06-01T23:59:59.000Z

249

PBFA II lithium beam characterization from inner-shell x-ray images  

SciTech Connect

The Particle Beam Fusion Accelerator (PBFA II) is not driving targets with ICF-relevant lithium ion beams. During the most recent lithium beam target series, time-integrated x-ray pinhole cameras viewed the ion-induced inner-shell x-ray fluorescence from the central gold cone target and a titanium-coated strip. Ion beam profiles at a nominal 10 mm radius and fixed azimuthal direction were obtained from images of the Ti K{sub {alpha}}, fluorescence of a Ti-coated Al diagnostic wire. The gold cone gave us beam profiles at a nominal 3 mm radius and at all azimuthal angles from the Au L{sub {alpha}} fluorescence. From these profiles, we obtained the ion beam vertical focus position, full-width-at-half-maximum, and the degree of azimuthal uniformity for the lithium target shots. For these initial results, beam steering problems were evident. Azimuthal uniformity was measured from the ion beam footprint on the outer Au case (predominantly Au L{sub {alpha}}) of the hohlraum target and were found to be in the same range (up to 30%) as for previous proton beam target series. We then present plans for Li beam diagnostics for an upcoming target experimental series.

Moats, A.R.; Derzon, M.S.; Chandler, G.A.; Dukart, R.J.; Haill, T.A.

1994-05-01T23:59:59.000Z

250

Investigation of the signature of lung tissue in X-ray grating-based phase-contrast imaging  

E-Print Network (OSTI)

Purpose: Grating-based X-ray phase-contrast imaging is a promising modality increasing the soft tissue contrast in medical imaging. In this work, the signature of lung tissue in X-ray grating-based physe-contrast imaging is investigated. Methods: We used a Talbot-Lau interferometer for our investigations of two C57BL/6 mice. Both underwent projection imaging and computed tomography. Results: The results show that the three images obtained by X-ray phase-contrast imaging show complementary anatomical structures. Especially the dark field image allows a more-exact determination of the position of the lung in the chest cavity. Conclusion: Due to its sensitivity to granular structures, the dark field image may be used for the diagnosis of lung diseases in earlier stages or without a CT scan. Furthermore, X-ray phase-contrast imaging may also have great potential in the application of animal laboratory sciences to reduce the number of required animals used in long-term translational, toxicity, and regenerative med...

Weber, Thomas; Haas, Wilhelm; Pelzer, Georg; Rieger, Jens; Ritter, André; Wucherer, Lukas; Braun, Jan Matthias; Durst, Jürgen; Michel, Thilo; Anton, Gisela

2012-01-01T23:59:59.000Z

251

High dynamic range pixel architecture for advanced diagnostic medical x-ray imaging applications  

SciTech Connect

The most widely used architecture in large-area amorphous silicon (a-Si) flat panel imagers is a passive pixel sensor (PPS), which consists of a detector and a readout switch. While the PPS has the advantage of being compact and amenable toward high-resolution imaging, small PPS output signals are swamped by external column charge amplifier and data line thermal noise, which reduce the minimum readable sensor input signal. In contrast to PPS circuits, on-pixel amplifiers in a-Si technology reduce readout noise to levels that can meet even the stringent requirements for low noise digital x-ray fluoroscopy (<1000 noise electrons). However, larger voltages at the pixel input cause the output of the amplified pixel to become nonlinear thus reducing the dynamic range. We reported a hybrid amplified pixel architecture based on a combination of PPS and amplified pixel designs that, in addition to low noise performance, also resulted in large-signal linearity and consequently higher dynamic range [K. S. Karim et al., Proc. SPIE 5368, 657 (2004)]. The additional benefit in large-signal linearity, however, came at the cost of an additional pixel transistor. We present an amplified pixel design that achieves the goals of low noise performance and large-signal linearity without the need for an additional pixel transistor. Theoretical calculations and simulation results for noise indicate the applicability of the amplified a-Si pixel architecture for high dynamic range, medical x-ray imaging applications that require switching between low exposure, real-time fluoroscopy and high-exposure radiography.

Izadi, Mohammad Hadi; Karim, Karim S. [School of Engineering Science, Simon Fraser University, Burnaby, British Columbia V5A 1S6 (Canada)

2006-05-15T23:59:59.000Z

252

Argonne CNM: X-Ray Microscopy Capabilities  

NLE Websites -- All DOE Office Websites (Extended Search)

X-Ray Microscopy Facilities X-Ray Microscopy Facilities The Hard X-Ray Nanoprobe (HXN) facility provides scanning fluorescence, scanning diffraction, and full-field transmission and tomographic imaging capabilities with a spatial resolution of 30 nm over a spectral range of 6-12 keV. Modes of Operation Full-Field Transmission Imaging and Nanotomography X-ray transmission imaging uses both the absorption and phase shift of the X-ray beam by the sample as contrast mechanisms. Absorption contrast is used to map the sample density. Elemental constituents can be located by using differential edge contrast in this mode. Phase contrast can be highly sensitive to edges and interfaces even when the X-ray absorption is weak. These contrast mechanisms are exploited to image samples rapidly in full-field transmission mode under various environmental conditions, or combined with nanotomography methods to study the three-dimensional structure of complex and amorphous nanomaterials with the HXN.

253

Aerosol Imaging with a Soft X-ray Free Electron Laser  

SciTech Connect

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

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

2011-08-22T23:59:59.000Z

254

Multicontrast x-ray computed tomography imaging using Talbot-Lau interferometry without phase stepping  

SciTech Connect

Purpose: The purpose of this work is to demonstrate that multicontrast computed tomography (CT) imaging can be performed using a Talbot-Lau interferometer without phase stepping, thus allowing for an acquisition scheme like that used for standard absorption CT. Methods: Rather than using phase stepping to extract refraction, small-angle scattering (SAS), and absorption signals, the two gratings of a Talbot-Lau interferometer were rotated slightly to generate a moire pattern on the detector. A Fourier analysis of the moire pattern was performed to obtain separate projection images of each of the three contrast signals, all from the same single-shot of x-ray exposure. After the signals were extracted from the detector data for all view angles, image reconstruction was performed to obtain absorption, refraction, and SAS CT images. A physical phantom was scanned to validate the proposed data acquisition method. The results were compared with a phantom scan using the standard phase stepping approach. Results: The reconstruction of each contrast mechanism produced the expected results. Signal levels and contrasts match those obtained using the phase stepping technique. Conclusions: Absorption, refraction, and SAS CT imaging can be achieved using the Talbot-Lau interferometer without the additional overhead of long scan time and phase stepping.

Bevins, Nicholas; Zambelli, Joseph; Li Ke; Qi Zhihua; Chen Guanghong [Department of Medical Physics, University of Wisconsin-Madison, 1111 Highland Avenue, Madison, Wisconsin 53705 (United States); Department of Medical Physics, University of Wisconsin-Madison, 1111 Highland Avenue, Madison, Wisconsin 53705 (United States) and Department of Radiology, University of Wisconsin-Madison, 600 Highland Avenue, Madison, Wisconsin 53792 (United States)

2012-01-15T23:59:59.000Z

255

Coherent X-ray Imaging Data Bank (CXIDB): An Open Repository for CXI Experimental Data  

DOE Data Explorer (OSTI)

Nowadays there are several groups around the world doing excellent work using different kinds of techniques all based on the physics of coherent X-ray imaging (CXI). Due to several reasons, including lack of a standard file format, there has been limited sharing of data which severely limits possible synergies inside the community. At the same time there is a population of researchers who do not have access to the facilities required to make such kinds of experiments, or do not have the expertise and resources necessary to carry them out. But many of them would be able to test new ideas and techniques if they would have access to the experimental data. The main goal of the Coherent X-ray Imaging Data Bank is to address these problems by creating an open repository for CXI experimental data. Such a repository provides several important benefits including: Expansion of the CXI community directly leading to an increase in the science output, the existence of an archival place for all the experimental data would ensure that such data does not gets lost forever when the group that did the experiment is no longer interested in the data, the availability of the experimental data to the entire community greatly facilitates reproducibility, leading to higher quality and more transparent science, the development of a well documented file format for CXI data facilitates data sharing and might one day lead to its emergence as a de facto standard. Current free electron laser facilities such as the LCLS are capable of producing very large amounts of data (20TB a day) and the coming European FEL is expected to increase this rate a factor of 500. The analyzes of such large bodies of data will have to be distributed through a large community to make it manageable, and this repository could be an important facilitator in this process.

256

Structure of Hydrated Poly(d,l-lactic acid) Studied with X-ray Diffraction and Molecular Simulation Methods  

DOE Green Energy (OSTI)

The effect of hydration on the molecular structure of amorphous poly(D,L-lactic acid) (PDLLA) with 50:50 L-to-D ratio has been studied by combining experiments with molecular simulations. X-ray diffraction measurements revealed significant changes upon hydration in the structure functions of the copolymer. Large changes in the structure functions at 10 days of incubation coincided with the large increase in the water uptake from {approx} 1 to {approx} 40% and the formation of voids in the film. Computer modeling based on the recently developed TIGER2/TIGER3 mixed sampling scheme was used to interpret these changes by efficiently equilibrating both dry and hydrated models of PDLLA. Realistic models of bulk amorphous PDLLA structure were generated as demonstrated by close agreement between the calculated and the experimental structure functions. These molecular simulations were used to identify the interactions between water and the polymer at the atomic level including the change of positional order between atoms in the polymer due to hydration. Changes in the partial O-O structure functions, about 95% of which were due to water-polymer interactions, were apparent in the radial distribution functions. These changes, and somewhat smaller changes in the C-C and C-O partial structure functions, clearly demonstrated the ability of the model to capture the hydrogen-bonding interactions between water and the polymer, with the probability of water forming hydrogen bonds with the carbonyl oxygen of the ester group being about 4 times higher than with its ether oxygen.

Li, Xianfeng; Murthy, N. Sanjeeva; Latour, Robert A. (Clemson); (Rutgers)

2012-10-10T23:59:59.000Z

257

3D Imaging of Nickel Oxidation States using Full Field X-ray Absorption Near Edge Structure Nanotomography  

Science Conference Proceedings (OSTI)

Reduction-oxidation (redox) cycling of the nickel electrocatalyst phase in the solid oxide fuel cell (SOFC) anode can lead to performance degradation and cell failure. A greater understanding of nickel redox mechanisms at the microstructural level is vital to future SOFC development. Transmission x-ray microscopy (TXM) provides several key techniques for exploring oxidation states within SOFC electrode microstructure. Specifically, x-ray nanotomography and x-ray absorption near edge structure (XANES) spectroscopy have been applied to study samples of varying nickel (Ni) and nickel oxide (NiO) compositions. The imaged samples are treated as mock SOFC anodes containing distinct regions of the materials in question. XANES spectra presented for the individual materials provide a basis for the further processing and analysis of mixed samples. Images of composite samples obtained are segmented, and the distinct nickel and nickel oxide phases are uniquely identified using full field XANES spectroscopy. Applications to SOFC analysis are discussed.

Nelson, George; Harris, William; Izzo, John; Grew, Kyle N. (Connecticut); (USARL)

2012-01-20T23:59:59.000Z

258

Extended Field of View Soft X-Ray Fourier Transform Holography: Toward Imaging Ultrafast Evolution in a Single Shot  

Science Conference Proceedings (OSTI)

Panoramic full-field imaging is demonstrated by applying spatial multiplexing to Fourier transform holography. Multiple object and reference waves extend the effective field of view for lensless imaging without compromising the spatial resolution. In this way, local regions of interest distributed throughout a sample can be simultaneously imaged with high spatial resolution. A method is proposed for capturing multiple ultrafast images of a sample with a single x-ray pulse.

Schlotter, W.F.; /Stanford U., Appl. Phys. Dept. /SLAC, SSRL; Luening, J.; /Paris, Lab Chim. Quantique /SOLEIL, Saint-Aubin /BESSY, Berlin; Rick, R.; Chen, K.; /Stanford U., Appl. Phys. Dept. /SLAC, SSRL; Scherz, A.; /SLAC, SSRL; Eisebitt, S.; Guenther, C.M.; Eberhardt, W.; /BESSY, Berlin; Hellwig, O.; /Hitachi Global Stor. Tech., San Jose; Stohr, J.; /SLAC, SSRL

2009-04-29T23:59:59.000Z

259

3-dimensional imaging system using crystal diffraction lenses  

DOE Patents (OSTI)

A device for imaging a plurality of sources of x-ray and gamma-ray radiation is provided. Diffracting crystals are used for focussing the radiation and directing the radiation to a detector which is used for analyzing their addition to collect data as to the location of the source of radiation. A computer is used for converting the data to an image. The invention also provides for a method for imaging x-ray and gamma radiation by supplying a plurality of sources of radiation; focussing the radiation onto a detector; analyzing the focused radiation to collect data as to the type and location of the radiation; and producing an image using the data.

Smither, Robert K. (Hinsdale, IL)

1999-01-01T23:59:59.000Z

260

RHESSI MICROFLARE STATISTICS. II. X-RAY IMAGING, SPECTROSCOPY, AND ENERGY DISTRIBUTIONS I. G. Hannah, S. Christe,1  

E-Print Network (OSTI)

RHESSI MICROFLARE STATISTICS. II. X-RAY IMAGING, SPECTROSCOPY, AND ENERGY DISTRIBUTIONS I. G distribution of RHESSI flares and compare it to previous thermal energy distributions of transient events. We flares down to nanoflares. The fre- quency distribution of the energy in these events has been studied

California at Berkeley, University of

Note: This page contains sample records for the topic "x-ray diffraction imaging" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


261

Atomic Resolution Coherent Diffractive Imaging and Ultrafast Science  

Science Conference Proceedings (OSTI)

A major scientific challenge is determining the 3-D atomic structure of small nanostructures, including single molecules. Coherent diffractive imaging (CDI) is a promising approach. Recent progress has demonstrated coherent diffraction patterns can be recorded from individual nanostructures and phased to reconstruct their structure. However, overcoming the dose limit imposed by radiation damage is a major obstacle toward the full potential of CDI. One approach is to use ultrafast x-ray or electron pulses. In electron diffraction, amplitudes recorded in a diffraction pattern are unperturbed by lens aberrations, defocus, and other microscope resolution-limiting factors. Sub-A signals are available beyond the information limit of direct imaging. Significant contrast improvement is obtained compared to high-resolution electron micrographs. progress has also been made in developing time-resolved electron diffraction and imaging for the study of ultrafast dynamic processes in materials. This talk will cover these crosscutting issues and the convergence of electron and x-ray diffraction techniques toward structure determination of single molecules.

Zuo, Jian-min [University of Illinois

2011-01-12T23:59:59.000Z

262

Tautomerism in liquid 1,2,3-triazole: a combined Energy-Dispersive X-Ray Diffraction, Molecular Dynamics and FTIR study  

E-Print Network (OSTI)

In this work, we report a multitechnique (energy-dispersive X-Ray diffraction, computational methods and FT-IR spectroscopy) study of the tautomeric equilibrium of 1,2,3-triazole, one of the few small nitrogen-containing eterocycles liquid at room temperature. The T-2H form (C2v symmetry) is found to be strongly favored in gas and solid phases, whereas the neat liquid gives diffraction patterns that can be interpreted satisfactorily with the structure functions calculated from some molecular dynamics results for both T-2H and T-1H tautomers, although the T-2H form gives a slightly better agreement.

Marco Bellagamba; Luigi Bencivenni; Lorenzo Gontrani; Leonardo Guidoni; Claudia Sadun

2013-01-18T23:59:59.000Z

263

Calculation of the parameters of the X-ray diffraction station with adaptive segmented optics on the side beam from the wiggler of the Sibir'-2 storage ring  

Science Conference Proceedings (OSTI)

The mounting of an X-ray diffraction station on the side beam of a 19-pole superconducting wiggler makes it possible not only to use the central synchrotron radiation beam with a wavelength of 0.5 Angstrom-Sign , but also to solve problems requiring softer X rays at a synchrotron radiation (SR) intensity exceeding that for the beams from the bending magnet. A numerical simulation of the formation of photon beams from a source and their transmission through the elements of the station (and through the station as a whole) allows one to calculate the parameters of the station, compare it with the existing analogs, determine its potential and actual efficiency of its elements, and estimate the adjustment quality. A numerical simulation of the SR source on the side beam from the wiggler and the focusing channel (segmented condenser mirror, monochromator with sagittal focusing by the segmented second crystal, and segmented focusing mirror) has been performed. The sizes of the focus and the divergence of rays in it are determined with allowance for the finite sizes of segments. The intensity of radiation with a wavelength {lambda} = 1.0 Angstrom-Sign in the focus is determined taking into account the loss in the SR extraction channel and in the focusing channel. The values of the critical wavelength for the side beam from the wiggler and the wavelength resolution are calculated. The intensities in the X-ray diffraction pattern and its angular resolution are found.

Molodenskii, D. S.; Kheiker, D. M., E-mail: kheiker@ns.crys.ras.ru [Russian Academy of Sciences, Shubnikov Institute of Crystallography (Russian Federation); Korchuganov, V. N. [National Research Center Kurchatov Institute (Russian Federation); Konoplev, E. E. [NPO Luch (Russian Federation); Dorovatovskii, P. V. [National Research Center Kurchatov Institute (Russian Federation)

2012-05-15T23:59:59.000Z

264

Imaging X-ray spectroscopy with micro-X and Chandra  

E-Print Network (OSTI)

High spectral resolution observations of X-ray phenomena have the potential to uncover new physics. Currently, only point sources can be probed with high resolution spectra, using gratings. Extended objects like supernova ...

Rutherford, John (John Morton)

2013-01-01T23:59:59.000Z

265

Radiation exposure in X-ray-based imaging techniques used in osteoporosis  

E-Print Network (OSTI)

to low levels of ionizing radiation: BEIR VII Phase 2. TheBlake G, Genant HK (1999) Radiation exposure in bone mineralGuglielmi Thomas M. Link Radiation exposure in X-ray-based

Damilakis, John; Adams, Judith E.; Guglielmi, Giuseppe; Link, Thomas M.

2010-01-01T23:59:59.000Z

266

P2-26: X-ray Micro-Laue Diffraction in 3D at the Canadian Light ...  

Science Conference Proceedings (OSTI)

P1-04: 3D Microstructural Characterization of Uranium Oxide as a Surrogate Nuclear ... P1-15: Gating System Optimisation Design Study of a Cast Automobile ... P2-27: Characterization of Carbonate Rocks through X-ray Microtomography.

267

Imaging of the Host Galaxies of Three X-Ray Selected BL Lacertae Objects  

E-Print Network (OSTI)

Hubble Space Telescope (HST) WFPC-2 I-band (F814W) images of three X-ray selected BL Lacertae objects (MS1221.8+2452, MS1407.9+5954, & MS2143.4+0704) reveal that each of these BL Lac objects is well-centered in an extended nebulosity that is consistent in brightness and morphology with being light from an elliptical galaxy at the previously reported redshifts of these BL Lac objects. Each of the detected host galaxies have radial surface brightness profiles that are well fit by a DeVaucouleurs' law with effective radii of between 3 to 12 kpc (H_0=50 km s^{-1} Mpc^{-1}, q_0 = 0). The absolute magnitudes of the host galaxies fall in the range -24.7 < M_I < -23.5, in the range of luminosities determined for other BL Lacertae object host galaxies. In addition to allowing the measurement of the host galaxy magnitudes and radial surface brightness profiles, the HST images allow a search for substructure in the host galaxies and the presence of close companion galaxies at spatial resolutions not yet achievable from the ground. While no evidence was found for any ``bars'' or spiral arms, ``boxy'' isophotes are present in the host galaxy of at least one of the three objects observed as part of this study (MS2143.4+0704). The apparent magnitudes and image properties of the companions of the BL Lac objects are catalogued as part of this work. The three BL Lacs appear to occur in diverse environments, from being fairly isolated (MS1221.8+2452) to possibly being a member of a rich group of galaxies (MS1407.9+5954).

Buell T. Jannuzi; Brian Yanny; Chris Impey

1997-06-03T23:59:59.000Z

268

Imaging of High-Energy X-Ray Emission from Cryogenic Thermonuclear Fuel Implosions on the NIF  

SciTech Connect

Accurately assessing and optimizing the implosion performance of inertial confinement fusion capsules is a crucial step to achieving ignition on the NIF. We have applied differential filtering (matched Ross filter pairs) to provide spectrally resolved time-integrated absolute x-ray self-emission images of the imploded core of cryogenic layered targets. Using bremsstrahlung assumptions, the measured absolute x-ray brightness allows for the inference of electron temperature, electron density, hot spot mass, mix mass, and pressure. Current inertial confinement fusion (ICF) experiments conducted on the National Ignition Facility (NIF) seek to indirectly drive a spherical implosion, compressing and igniting a deuterium-tritium fuel. This DT fuel capsule is cryogenically prepared as a solid ice layer surrounded by a low-Z ablator material. Ignition will occur when the hot spot approaches sufficient temperature ({approx}3-4 keV) and {rho}R ({approx}0.3 g/cm{sup 2}) such that alpha deposition can further heat the hot spot and generate a self-sustaining burn wave. During the implosion, the fuel mass becomes hot enough to emit large amounts of x-ray radiation, the spectra and spatial variation of which contains key information that can be used to evaluate the implosion performance. The Ross filter diagnostic employs differential filtering to provide spectrally resolved, time-integrated, absolute x-ray self-emission images of the imploded core of cryogenic layered targets.

Ma, T

2012-05-01T23:59:59.000Z

269

Image-based spectral distortion correction for photon-counting x-ray detectors  

Science Conference Proceedings (OSTI)

Purpose: To investigate the feasibility of using an image-based method to correct for distortions induced by various artifacts in the x-ray spectrum recorded with photon-counting detectors for their application in breast computed tomography (CT). Methods: The polyenergetic incident spectrum was simulated with the tungsten anode spectral model using the interpolating polynomials (TASMIP) code and carefully calibrated to match the x-ray tube in this study. Experiments were performed on a Cadmium-Zinc-Telluride (CZT) photon-counting detector with five energy thresholds. Energy bins were adjusted to evenly distribute the recorded counts above the noise floor. BR12 phantoms of various thicknesses were used for calibration. A nonlinear function was selected to fit the count correlation between the simulated and the measured spectra in the calibration process. To evaluate the proposed spectral distortion correction method, an empirical fitting derived from the calibration process was applied on the raw images recorded for polymethyl methacrylate (PMMA) phantoms of 8.7, 48.8, and 100.0 mm. Both the corrected counts and the effective attenuation coefficient were compared to the simulated values for each of the five energy bins. The feasibility of applying the proposed method to quantitative material decomposition was tested using a dual-energy imaging technique with a three-material phantom that consisted of water, lipid, and protein. The performance of the spectral distortion correction method was quantified using the relative root-mean-square (RMS) error with respect to the expected values from simulations or areal analysis of the decomposition phantom. Results: The implementation of the proposed method reduced the relative RMS error of the output counts in the five energy bins with respect to the simulated incident counts from 23.0%, 33.0%, and 54.0% to 1.2%, 1.8%, and 7.7% for 8.7, 48.8, and 100.0 mm PMMA phantoms, respectively. The accuracy of the effective attenuation coefficient of PMMA estimate was also improved with the proposed spectral distortion correction. Finally, the relative RMS error of water, lipid, and protein decompositions in dual-energy imaging was significantly reduced from 53.4% to 6.8% after correction was applied. Conclusions: The study demonstrated that dramatic distortions in the recorded raw image yielded from a photon-counting detector could be expected, which presents great challenges for applying the quantitative material decomposition method in spectral CT. The proposed semi-empirical correction method can effectively reduce these errors caused by various artifacts, including pulse pileup and charge sharing effects. Furthermore, rather than detector-specific simulation packages, the method requires a relatively simple calibration process and knowledge about the incident spectrum. Therefore, it may be used as a generalized procedure for the spectral distortion correction of different photon-counting detectors in clinical breast CT systems.

Ding Huanjun; Molloi, Sabee [Department of Radiological Sciences, University of California, Irvine, California 92697 (United States)

2012-04-15T23:59:59.000Z

270

Diffraction efficiency of 200-nm-period critical-angle transmission gratings in the soft x-ray and extreme ultraviolet wavelength bands  

SciTech Connect

We report on measurements of the diffraction efficiency of 200-nm-period freestanding blazed transmission gratings for wavelengths in the 0.96 to 19.4 nm range. These critical-angle transmission (CAT) gratings achieve highly efficient blazing over a broad band via total external reflection off the sidewalls of smooth, tens of nanometer thin ultrahigh aspect-ratio silicon grating bars and thus combine the advantages of blazed x-ray reflection gratings with those of more conventional x-ray transmission gratings. Prototype gratings with maximum depths of 3.2 and 6 {mu}m were investigated at two different blaze angles. In these initial CAT gratings the grating bars are monolithically connected to a cross support mesh that only leaves less than half of the grating area unobstructed. Because of our initial fabrication approach, the support mesh bars feature a strongly trapezoidal cross section that leads to varying CAT grating depths and partial absorption of diffracted orders. While theory predicts broadband absolute diffraction efficiencies as high as 60% for ideal CAT gratings without a support mesh, experimental results show efficiencies in the range of {approx}50-100% of theoretical predictions when taking the effects of the support mesh into account. Future minimization of the support mesh therefore promises broadband CAT grating absolute diffraction efficiencies of 50% or higher.

Heilmann, Ralf K.; Ahn, Minseung; Bruccoleri, Alex; Chang, Chih-Hao; Gullikson, Eric M.; Mukherjee, Pran; Schattenburg, Mark L.

2011-04-01T23:59:59.000Z

271

Robustness of phase retrieval methods in x-ray phase contrast imaging: A comparison  

SciTech Connect

Purpose: The robustness of the phase retrieval methods is of critical importance for limiting and reducing radiation doses involved in x-ray phase contrast imaging. This work is to compare the robustness of two phase retrieval methods by analyzing the phase maps retrieved from the experimental images of a phantom. Methods: Two phase retrieval methods were compared. One method is based on the transport of intensity equation (TIE) for phase contrast projections, and the TIE-based method is the most commonly used method for phase retrieval in the literature. The other is the recently developed attenuation-partition based (AP-based) phase retrieval method. The authors applied these two methods to experimental projection images of an air-bubble wrap phantom for retrieving the phase map of the bubble wrap. The retrieved phase maps obtained by using the two methods are compared. Results: In the wrap's phase map retrieved by using the TIE-based method, no bubble is recognizable, hence, this method failed completely for phase retrieval from these bubble wrap images. Even with the help of the Tikhonov regularization, the bubbles are still hardly visible and buried in the cluttered background in the retrieved phase map. The retrieved phase values with this method are grossly erroneous. In contrast, in the wrap's phase map retrieved by using the AP-based method, the bubbles are clearly recovered. The retrieved phase values with the AP-based method are reasonably close to the estimate based on the thickness-based measurement. The authors traced these stark performance differences of the two methods to their different techniques employed to deal with the singularity problem involved in the phase retrievals. Conclusions: This comparison shows that the conventional TIE-based phase retrieval method, regardless if Tikhonov regularization is used or not, is unstable against the noise in the wrap's projection images, while the AP-based phase retrieval method is shown in these experiments to be superior to the TIE-based method for the robustness in performing the phase retrieval.

Yan, Aimin; Wu, Xizeng; Liu, Hong [Department of Radiology, University of Alabama at Birmingham, Birmingham, Alabama 35233 (United States); Center for Bioengineering and School of Electrical and Computer Engineering, University of Oklahoma, Norman, Oklahoma 73019 (United States)

2011-09-15T23:59:59.000Z

272

Strain evolution in Si substrate due to implantation of MeV ion observed by extremely asymmetric x-ray diffraction  

Science Conference Proceedings (OSTI)

We studied the strain introduced in a Si(111) substrate due to MeV ion implantation using extremely asymmetric x-ray diffraction and measured the rocking curves of asymmetrical 113 diffraction for the Si substrates implanted with a 1.5 MeV Au{sup 2+} ion at fluence values of 1x10{sup 13}, 5x10{sup 13}, and 1x10{sup 14}/cm{sup 2}. The measured curves consisted of a bulk peak and accompanying subpeak with an interference fringe. The positional relationship of the bulk peak to the subpeak and the intensity variation of those peaks with respect to the wavelengths of the x rays indicated that crystal lattices near the surface were strained; the lattice spacing of surface normal (111) planes near the surface was larger than that of the bulk. Detailed strain profiles along the depth direction were successfully estimated using a curve-fitting method based on Darwin's dynamical diffraction theory. Comparing the shapes of resultant strain profiles, we found that a strain evolution rapidly occurred within a depth of approx300 nm at fluence values between 1x10{sup 13} and 5x10{sup 13}/cm{sup 2}. This indicates that formation of the complex defects progressed near the surface when the fluence value went beyond a critical value between 1x10{sup 13} and 5x10{sup 13}/cm{sup 2} and the defects brought a large strain to the substrate.

Emoto, T. [Department of Physics, Toyota National College of Technology, 2-1, Eisei-cho, Toyota 471-8525 (Japan); Ghatak, J.; Satyam, P. V. [Institute of Physics, Sachivalaya Marg, Bhubaneswar 751005 (India); Akimoto, K. [Department of Quantum Engineering, Nagoya University, Furo-cho, Chikusa-ku, Naoyga 464-8603 (Japan)

2009-08-15T23:59:59.000Z

273

Synchrotron-based coherent scatter x-ray projection imaging using an array of monoenergetic pencil beams  

SciTech Connect

Traditional projection x-ray imaging utilizes only the information from the primary photons. Low-angle coherent scatter images can be acquired simultaneous to the primary images and provide additional information. In medical applications scatter imaging can improve x-ray contrast or reduce dose using information that is currently discarded in radiological images to augment the transmitted radiation information. Other applications include non-destructive testing and security. A system at the Canadian Light Source synchrotron was configured which utilizes multiple pencil beams (up to five) to create both primary and coherent scatter projection images, simultaneously. The sample was scanned through the beams using an automated step-and-shoot setup. Pixels were acquired in a hexagonal lattice to maximize packing efficiency. The typical pitch was between 1.0 and 1.6 mm. A Maximum Likelihood-Expectation Maximization-based iterative method was used to disentangle the overlapping information from the flat panel digital x-ray detector. The pixel value of the coherent scatter image was generated by integrating the radial profile (scatter intensity versus scattering angle) over an angular range. Different angular ranges maximize the contrast between different materials of interest. A five-beam primary and scatter image set (which had a pixel beam time of 990 ms and total scan time of 56 min) of a porcine phantom is included. For comparison a single-beam coherent scatter image of the same phantom is included. The muscle-fat contrast was 0.10 {+-} 0.01 and 1.16 {+-} 0.03 for the five-beam primary and scatter images, respectively. The air kerma was measured free in air using aluminum oxide optically stimulated luminescent dosimeters. The total area-averaged air kerma for the scan was measured to be 7.2 {+-} 0.4 cGy although due to difficulties in small-beam dosimetry this number could be inaccurate.

Landheer, Karl [Ottawa Medical Physics Institute and Ottawa-Carleton Institute for Physics, Department of Physics, Carleton University, 1125 Colonel By Drive, Ottawa K1S 5B6 (Canada); Johns, Paul C. [Ottawa Medical Physics Institute and Ottawa-Carleton Institute for Physics, Department of Physics, Carleton University, 1125 Colonel By Drive, Ottawa K1S 5B6 (Canada); Department of Radiology, University of Ottawa (Canada)

2012-09-15T23:59:59.000Z

274

Imaging of high-energy x-ray emission from cryogenic thermonuclear fuel implosions on the NIF  

Science Conference Proceedings (OSTI)

Accurately assessing and optimizing the implosion performance of inertial confinement fusion capsules is a crucial step to achieving ignition on the NIF. We have applied differential filtering (matched Ross filter pairs) to provide broadband time-integrated absolute x-ray self-emission images of the imploded core of cryogenic layered implosions. This diagnostic measures the temperature- and density-sensitive bremsstrahlung emission and provides estimates of hot spot mass, mix mass, and pressure.

Ma, T.; Izumi, N.; Tommasini, R.; Bradley, D. K.; Bell, P.; Cerjan, C. J.; Dixit, S.; Doeppner, T.; Jones, O.; Landen, O. L.; LePape, S.; Mackinnon, A. J.; Park, H.-S.; Patel, P. K.; Prasad, R. R.; Ralph, J.; Smalyuk, V. A.; Springer, P. T.; Suter, L.; Town, R. P. J. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); and others

2012-10-15T23:59:59.000Z

275

X-ray microtomography  

SciTech Connect

In this tutorial, we describe X-ray microtomography as a technique to nondestructively characterize material microstructure in three dimensions at a micron level spatial resolution. While commercially available laboratory scale instrumentation is available, we focus our attention on synchrotron-based systems, where we can exploit a high flux, monochromatic X-ray beam to produce high fidelity three-dimensional images. A brief description of the physics and the mathematical analysis behind the technique is followed by example applications to specific materials characterization problems, with a particular focus on the utilization of three-dimensional image processing that can be used to extract a wide range of useful information.

Landis, Eric N., E-mail: landis@maine.edu [Department of Civil and Environmental Engineering, University of Maine, 5711 Boardman Hall, Orono, Maine 04469 (United States); Keane, Denis T., E-mail: dtkeane@northwestern.edu [Department of Materials Science and Engineering, Northwestern University (United States); DND-CAT, Advanced Photon Source, Argonne National Laboratory, Bldg. 432/A002, 9700 S. Cass Ave, Argonne, Illinois 60439 (United States)

2010-12-15T23:59:59.000Z

276

Application of Image And X-Ray Microtomography Technique To Quantify Filler Distribution In Thermoplastic-Natural Rubber Blend Composites  

Science Conference Proceedings (OSTI)

X-ray microtomography and ImageJ 1.39 u is used as a tool to quantify volume percentage of B{sub 4}C as fillers in thermoplastic-natural rubber blend composites. The use of percentage of area occupied by fillers as obtain from ImageJ from the microtomography sliced images enables the proposed technique to easily obtain the amount volume percentage of B{sub 4}C in the composite non-destructively. Comparison with other technique such as density measurement and chemical analysis proves the proposed technique as one of the promising approach.

Ahmad, Sahrim; Rasid, Rozaidi; Mouad, A. T. [Faculty of Applied Science and Technology, Universiti Kebangsaan Malaysia (UKM), Bandar Baru Bangi, 43000 Kajang (Malaysia); Aziz Mohamed, A.; Abdullah, Jaafar; Dahlan, M.; Mohamad, Mahathir; Jamro, Rafhayudi; Hamzah Harun, M. [Malaysian Nuclear Agency, Bangi, 43000 Kajang (Malaysia); Yazid, Hafizal [Faculty of Applied Science and Technology, Universiti Kebangsaan Malaysia (UKM), Bandar Baru Bangi, 43000 Kajang (Malaysia); Hafizal Yazid, Faculty of Applied Science and Technology, Universiti Kebangsaan Malaysia (UKM), Bandar Baru Bangi, 43000 Kajang (Malaysia); Abdullah, W. Saffiey W.

2010-01-05T23:59:59.000Z

277

An X-ray diffraction study of pressure-induced phase transitions in Bi{sub 2}MoO{sub 6}  

SciTech Connect

Synchrotron based X-ray diffraction through a diamond anvil cell was used to determine the equations of state and pressure-induced phase transitions in Bi{sub 2}MoO{sub 6}. It was observed that Bi{sub 2}MoO{sub 6} undergoes a phase transformation at {approx}6.8 GPa. The high-pressure phase can be indexed to the orthorhombic structure and the transition is reversible on decompression from {approx}47 GPa. The bulk moduli of the low and high-pressure phases were calculated, while holding K Prime =4, to be: K=51{+-}1 GPa and K=141.5 {+-}0.1 GPa, respectively. - Graphical abstract: The material Bi{sub 2}MoO{sub 6} was placed inside a diamond anvil cell and then studied under high pressure at beamline X17C of the National Synchrotron Light source. X-ray diffraction data was analyzed using the Rietveld method. Highlights: Black-Right-Pointing-Pointer A high-pressure study of bismuth molybdate was performed. Black-Right-Pointing-Pointer Pressure-induced phase transitions were observed. Black-Right-Pointing-Pointer The low pressure phase bulk modulus was calculated to be K=51{+-}1 GPa. Black-Right-Pointing-Pointer The high pressure phase bulk modulus was calculated to be B=141.5{+-}0.1 GPa.

Scott, Paul R., E-mail: prscott933@hotmail.com [Department of Physics, University of Missouri-Kansas City, 5110 Rockhill Road, MO 64110 (United States); Crow, J.A. [Department of Physics, University of Missouri-Kansas City, 5110 Rockhill Road, MO 64110 (United States)] [Department of Physics, University of Missouri-Kansas City, 5110 Rockhill Road, MO 64110 (United States); Maczka, M. [Institute of Low Temperature and Structure Research, Polish Academy of Sciences, PO Box 1410, 50-950 Wroclaw 2 (Poland)] [Institute of Low Temperature and Structure Research, Polish Academy of Sciences, PO Box 1410, 50-950 Wroclaw 2 (Poland); Kruger, M.B. [Department of Physics, University of Missouri-Kansas City, 5110 Rockhill Road, MO 64110 (United States)] [Department of Physics, University of Missouri-Kansas City, 5110 Rockhill Road, MO 64110 (United States)

2012-10-15T23:59:59.000Z

278

Multi-energy x-ray imaging and sensing for diagnostic and control of the burning plasma  

Science Conference Proceedings (OSTI)

New diagnostic and sensor designs are needed for future burning plasma (BP) fusion experiments, having good space and time resolution and capable of prolonged operation in the harsh BP environment. We evaluate the potential of multi-energy x-ray imaging with filtered detector arrays for BP diagnostic and control. Experimental studies show that this simple and robust technique enables measuring with good accuracy, speed, and spatial resolution the T{sub e} profile, impurity content, and MHD activity in a tokamak. Applied to the BP this diagnostic could also serve for non-magnetic sensing of the plasma position, centroid, ELM, and RWM instability. BP compatible x-ray sensors are proposed using 'optical array' or 'bi-cell' detectors.

Stutman, D.; Tritz, K.; Finkenthal, M. [Department of Physics and Astronomy, Johns Hopkins University, Baltimore, Maryland 21218 (United States)

2012-10-15T23:59:59.000Z

279

The second-order differential phase contrast and its retrieval for imaging with x-ray Talbot interferometry  

SciTech Connect

Purpose: The x-ray differential phase contrast imaging implemented with the Talbot interferometry has recently been reported to be capable of providing tomographic images corresponding to attenuation-contrast, phase-contrast, and dark-field contrast, simultaneously, from a single set of projection data. The authors believe that, along with small-angle x-ray scattering, the second-order phase derivative {Phi}{sup Double-Prime }{sub s}(x) plays a role in the generation of dark-field contrast. In this paper, the authors derive the analytic formulae to characterize the contribution made by the second-order phase derivative to the dark-field contrast (namely, second-order differential phase contrast) and validate them via computer simulation study. By proposing a practical retrieval method, the authors investigate the potential of second-order differential phase contrast imaging for extensive applications. Methods: The theoretical derivation starts at assuming that the refractive index decrement of an object can be decomposed into {delta}={delta}{sub s}+{delta}{sub f}, where {delta}{sub f} corresponds to the object's fine structures and manifests itself in the dark-field contrast via small-angle scattering. Based on the paraxial Fresnel-Kirchhoff theory, the analytic formulae to characterize the contribution made by {delta}{sub s}, which corresponds to the object's smooth structures, to the dark-field contrast are derived. Through computer simulation with specially designed numerical phantoms, an x-ray differential phase contrast imaging system implemented with the Talbot interferometry is utilized to evaluate and validate the derived formulae. The same imaging system is also utilized to evaluate and verify the capability of the proposed method to retrieve the second-order differential phase contrast for imaging, as well as its robustness over the dimension of detector cell and the number of steps in grating shifting. Results: Both analytic formulae and computer simulations show that, in addition to small-angle scattering, the contrast generated by the second-order derivative is magnified substantially by the ratio of detector cell dimension over grating period, which plays a significant role in dark-field imaging implemented with the Talbot interferometry. Conclusions: The analytic formulae derived in this work to characterize the second-order differential phase contrast in the dark-field imaging implemented with the Talbot interferometry are of significance, which may initiate more activities in the research and development of x-ray differential phase contrast imaging for extensive preclinical and eventually clinical applications.

Yang Yi; Tang Xiangyang [Imaging and Medical Physics, Department of Radiology and Imaging Sciences, Emory University School of Medicine, 1701 Uppergate Dr., C-5018, Atlanta, Georgia 30322 (United States)

2012-12-15T23:59:59.000Z

280

A soft x-ray transmission grating imaging-spectrometer for the National Ignition Facility  

SciTech Connect

A soft x-ray transmission grating spectrometer has been designed for use on high energy-density physics experiments at the National Ignition Facility (NIF); coupled to one of the NIF gated x-ray detectors (GXD) it records sixteen time-gated spectra between 250 and 1000eV with 100ps temporal resolution. The trade-off between spectral and spatial resolution leads to an optimized design for measurement of emission around the peak of a 100-300eV blackbody spectrum. Performance qualification results from the NIF, the Trident Laser Facility and VUV beamline at the National Synchrotron Light Source (NSLS), evidence a <100{micro}m spatial resolution in combination with a source-size limited spectral resolution that is <10eV at photon energies of 300eV.

Moore, A S; Guymer, T M; Kline, J L; Morton, J; Taccetti, M; Lanier, N E; Bentley, C; Workman, J; Peterson, B; Mussack, K; Cowan, J; Prasad, R; Richardson, M; Burns, S; Kalantar, D H; Benedetti, L R; Bell, P; Bradley, D; Hsing, W; Stevenson, M

2012-05-01T23:59:59.000Z

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281

A soft x-ray transmission grating imaging-spectrometer for the National Ignition Facility  

SciTech Connect

A soft x-ray transmission grating spectrometer has been designed for use on high energy-density physics experiments at the National Ignition Facility (NIF); coupled to one of the NIF gated x-ray detectors it records 16 time-gated spectra between 250 and 1000 eV with 100 ps temporal resolution. The trade-off between spectral and spatial resolution leads to an optimized design for measurement of emission around the peak of a 100-300 eV blackbody spectrum. Performance qualification results from the NIF, the Trident Laser Facility and vacuum ultraviolet beamline at the National Synchrotron Light Source, evidence a <100 {mu}m spatial resolution in combination with a source-size limited spectral resolution that is <10 eV at photon energies of 300 eV.

Moore, A. S.; Guymer, T. M.; Morton, J.; Bentley, C.; Stevenson, M. [Directorate Science and Technology, AWE Aldermaston, Reading, RG7 4PR (United Kingdom); Kline, J. L.; Taccetti, M.; Lanier, N. E.; Workman, J.; Peterson, B.; Mussack, K.; Cowan, J. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Prasad, R.; Richardson, M.; Burns, S.; Kalantar, D. H.; Benedetti, L. R.; Bell, P.; Bradley, D.; Hsing, W. [Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551-0808 (United States)

2012-10-15T23:59:59.000Z

282

Effects of sulfation level on the desulfation behavior of pre-sulfated Pt BaO/Al2O3 lean NOx trap catalysts: a combined H2 Temperature-Programmed Reaction, in-situ sulfur K-edge X-ray Absorption Near-Edge Spectroscopy, X-ray Photoelectron Spectroscopy, and Time-Resolved X-ray Diffraction Study  

SciTech Connect

Desulfation by hydrogen of pre-sulfated Pt(2wt%) BaO(20wt%)/Al2O3 with various sulfur loading (S/Ba = 0.12, 0.31 and 0.62) were investigated by combining H2 temperature programmed reaction (TPRX), x-ray photoelectron spectroscopy (XPS), in-situ sulfur K-edge x-ray absorption near-edge spectroscopy (XANES), and synchrotron time-resolved x-ray diffraction (TR-XRD) techniques. We find that the amount of H2S desorbed during the desulfation in the H2 TPRX experiments is not proportional to the amount of initial sulfur loading. The results of both in-situ sulfur K-edge XANES and TR-XRD show that at low sulfur loadings, sulfates were transformed to a BaS phase and remained in the catalyst, rather than being removed as H2S. On the other hand, when the deposited sulfur level exceeded a certain threshold (at least S/Ba = 0.31) sulfates were reduced to form H2S, and the relative amount of the residual sulfide species in the catalyst was much less than at low sulfur loading. Unlike samples with high sulfur loading (e.g., S/Ba = 0.62), H2O did not promote the desulfation for the sample with S/Ba of 0.12, implying that the formed BaS species originating from the reduction of sulfates at low sulfur loading are more stable to hydrolysis. The results of this combined spectroscopy investigation provide clear evidence to show that sulfates at low sulfur loadings are less likely to be removed as H2S and have a greater tendency to be transformed to BaS on the material, leading to the conclusion that desulfation behavior of Pt BaO/Al2O3 lean NOx trap catalysts is markedly dependent on the sulfation levels.

Kim, Do Heui; Szanyi, Janos; Kwak, Ja Hun; Wang, Xianqin; Hanson, Jonathan C.; Engelhard, Mark H.; Peden, Charles HF

2009-04-03T23:59:59.000Z

283

Thermal strains in focusing channels of the stations for X-ray diffraction analysis in the Sibir-2 storage ring  

SciTech Connect

The thermal load caused by the absorption of synchrotron radiation in X-ray optical elements of the Belok and RSA stations leads to optics elements heating and induces strains upon simultaneous cooling. The heating of the cooled first crystal in the double-crystal monochromator causes its bending and increases the reflected beam divergence, which, in turn, results in the monochromatic beam intensity loss [1]. Numerical simulation makes it possible to more accurately determine the strains, choose the optimal monochromator design, estimate the vertical sizes of the focal spot and wavelength resolution in the focusing channel, correctly design the system for cooling the mirror at the channel input, and choose a design providing the minimum temperature of the beam-limiting slit knives.

Kheiker, D. M., E-mail: kheiker@ns.crys.ras.ru [Russian Academy of Sciences, Shubnikov Institute of Crystallography (Russian Federation); Konoplev, E. E. [NPO Luch (Russian Federation); Molodenskii, D. S.; Shishkov, V. A.; Dorovatovskii, P. V. [Russian Academy of Sciences, Shubnikov Institute of Crystallography (Russian Federation)

2010-09-15T23:59:59.000Z

284

Soft x-ray microscopy - a powerful analytical tool to image magnetism down to fundamental length and times scales  

Science Conference Proceedings (OSTI)

The magnetic properties of low dimensional solid state matter is of the utmost interest both scientifically as well as technologically. In addition to the charge of the electron which is the base for current electronics, by taking into account the spin degree of freedom in future spintronics applications open a new avenue. Progress towards a better physical understanding of the mechanism and principles involved as well as potential applications of nanomagnetic devices can only be achieved with advanced analytical tools. Soft X-ray microscopy providing a spatial resolution towards 10nm, a time resolution currently in the sub-ns regime and inherent elemental sensitivity is a very promising technique for that. This article reviews the recent achievements of magnetic soft X-ray microscopy by selected examples of spin torque phenomena, stochastical behavior on the nanoscale and spin dynamics in magnetic nanopatterns. The future potential with regard to addressing fundamental magnetic length and time scales, e.g. imaging fsec spin dynamics at upcoming X-ray sources is pointed out.

Fischer, Peter

2008-08-01T23:59:59.000Z

285

A uniformly redundant imaging array of penumbral apertures coupled with a heuristic reconstruction for hard x-ray and neutron imaging  

SciTech Connect

A coded imaging and decoding (image reconstruction) scheme was developed for diagnosing a hot and dense region emitting hard x-rays and neutrons in laser-fusion plasmas. Because the imager was a uniformly redundant array of penumbral aperture (URPA) arranged in an M-matrix, URPA leads to N times (N: the total number of apertures) enhancement of signal intensity in comparison with a single penumbral aperture. A recorded penumbral image was reconstructed by a computer-based heuristic method to reduce artifacts caused by noises contained in a penumbral image. Applicability of this technique was investigated by imaging x-rays emitted from laser-produced plasmas, demonstrating a spatial resolution of 16 {mu}m. Under the present conditions, the spatial resolution was determined dominantly by a detector resolution (10.5 {mu}m) and a signal-to-noise ratio of the obtained penumbral image.

Ueda, Tatsuki; Fujioka, Shinsuke; Nishimura, Hiroaki [Institute of Laser Engineering, Osaka University, 2-6, Yamada-oka, Suita, Osaka, 565-0871 (Japan); Nozaki, Shinya; Azuma, Rumiko [Transdisplinary Research Organization for Subtropics Island Studies, University of the Ryukyus, 1 Senbaru Nishihara, Okinawa, 903-0213 (Japan); Chen, Yen-Wei [College of Information Science and Engineering, Ritsumeikan University, 1-1-1 Nojihigasi Kusatsu, Shiga, 525-8577 (Japan)

2010-07-15T23:59:59.000Z

286

Probing the spin polarization of current by soft x-ray imaging of current-induced magnetic vortex dynamics  

SciTech Connect

Time-resolved soft X-ray transmission microscopy is applied to image the current-induced resonant dynamics of the magnetic vortex core realized in a micron-sized Permalloy disk. The high spatial resolution better than 25 nm enables us to observe the resonant motion of the vortex core. The result also provides the spin polarization of the current to be 0.67 {+-} 0.16 for Permalloy by fitting the experimental results with an analytical model in the framework of the spin-transfer torque.

Kasai, Shinya; Fischer, Peter; Im, Mi-Young; Yamada, Keisuke; Nakatani, Yoshinobu; Kobayashi, Kensuke; Kohno, Hiroshi; Ono, Teruo

2008-12-09T23:59:59.000Z

287

Computer analysis of four channel x-ray microscopy images to obtain source and spectral emission data on laser fusion  

SciTech Connect

It is possible to analyze the images obtained from the four- channel x- ray microscope to obtain reasonable estimates of source spatial and energy emission. The technique shown here is particularly useful when relative comparisons are desired in which, from shot to shot, few parameters are changed. These data are of use in fuel pellet design and in checking design code predictions. The technique should also apply to pinhole camera data. Largest uncertainties appear to be due to film energy/handling calibration and mirror efficiency measurements. (auth)

Harper, T.L.

1975-10-01T23:59:59.000Z

288

X-ray diffraction study of (TlInSe{sub 2}){sub 1-x}(TlGaTe{sub 2}){sub x} crystal system  

Science Conference Proceedings (OSTI)

The crystallographic and dynamic characteristics of TlInSe{sub 2} and TlGaTe{sub 2} crystals have been studied by X-ray diffraction in the temperature range of 85-320 K. The temperature dependences of the unit-cell parameters a of TlInSe{sub 2} and TlGaTe{sub 2} crystals, as well as their coefficients of thermal expansion along the [100] direction, are determined. The concentration dependences of the unit-cell parameters a and c for (TlInSe{sub 2}){sub 1-x}(TlGaTe{sub 2}){sub x} crystals are measured. Anomalies are found in the temperature dependences of the unit-cell parameters a and, correspondingly, the coefficient of thermal expansion, indicating the existence of phase transitions in TlInSe{sub 2} and TlGaTe{sub 2} crystals.

Sheleg, A. U., E-mail: sheleg@ifttp.bas-net.by; Zub, E. M.; Yachkovskii, A. Ya. [National Academy of Sciences of Belarus, State Scientific and Production Association, Scientific and Practical Materials Research Center (Belarus); Mustafaeva, S. N.; Kerimova, E. M. [Azerbaijan National Academy of Sciences, Institute of Physics (Azerbaijan)

2012-03-15T23:59:59.000Z

289

X-ray diffraction study of residual stresses in metal-matrix composite-jacketed steel cylinders subjected to internal pressure. Final report  

Science Conference Proceedings (OSTI)

The study of aluminum/silicon carbide metal matrix composite (MMC)-jacketed steel structural components was made because of their light weight and high stiffness. Steel 'liner' cylinders were wrapped with MMC 'jackets' with an all-hoop layup and put through various degrees of hydraulic autofrettage and thermal soak. In this report, the results from our x-ray diffraction residual stress measurements on cylinders using a position-sensitive scintillation detection system are discussed. Our experimental results are compared with theoretical predictions from a model based on the elastic-plastic analysis of a thick-walled cylinder subjected to internal pressure. Interpretation of the interference effect caused by the MMC jacket on the steel liner is also discussed.

Lee, S.L.; Doxbeck, M.; Capsimalis, G.

1992-03-01T23:59:59.000Z

290

QUANTITATIVE X-RAY POWDER DIFFRACTION ANALYSES OF CLAYS USING AN ORIENTING INTERNAL STANDARD AND PRESSED DISKS OF BULK SHALE SAMPLES  

E-Print Network (OSTI)

Abstraet--Quantitative analysis of clay minerals by X-ray powder diffraction requires oriented clays in order to increase detection limits of the analyses. This is achieved commonly either by smear or sedimentation techniques; however, these techniques can lead to poor analytical precision when used with an internal standard because they often produce non-homogeneous internal standard-clay mineral mixtures. Compaction of bulk shale material at 8000 psi in an hydraulic press produces preferred orientations comparable to that produced by smear or sedimentation. When used with a suitable platy internal standard which provides an estimate of clay mineral preferred orientation, excellent analytical precision is achieved routinely. Several lines of experimental evidence indicate that 1-5 /tm MoS2 is an ideal orienting internal standard for use with compaction mounts.

R. D. Cody; G. L. Thompson

1976-01-01T23:59:59.000Z

291

Surface X-Ray Diffraction Results on the III-V Droplet Heteroepitaxy Growth Process for Quantum Dots: Recent Understanding and Open Questions  

SciTech Connect

In recent years, epitaxial growth of self-assembled quantum dots has offered a way to incorporate new properties into existing solid state devices. Although the droplet heteroepitaxy method is relatively complex, it is quite relaxed with respect to the material combinations that can be used. This offers great flexibility in the systems that can be achieved. In this paper we review the structure and composition of a number of quantum dot systems grown by the droplet heteroepitaxy method, emphasizing the insights that these experiments provide with respect to the growth process. Detailed structural and composition information has been obtained using surface X-ray diffraction analyzed by the COBRA phase retrieval method. A number of interesting phenomena have been observed: penetration of the dots into the substrate ('nano-drilling') is often encountered; interdiffusion and intermixing already start when the group III droplets are deposited, and structure and composition may be very different from the one initially intended.

Cohen, Eyal; Elfassy, Naomi; Koplovitz, Guy; Yochelis, Shira; Shusterman, Sergey; Kumah, Divine P.; Yacoby, Yizhak; Clarke, Roy; Paltiel, Yossi (Michigan); (Hebrew)

2012-04-24T23:59:59.000Z

292

Cryotomography x-ray microscopy state  

Science Conference Proceedings (OSTI)

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.

Le Gros, Mark (Berkeley, CA); Larabell, Carolyn A. (Berkeley, CA)

2010-10-26T23:59:59.000Z

293

X-Ray Diffraction Study of MBE-Grown CaF2-CdF2 Superlattices on ...  

Science Conference Proceedings (OSTI)

About this Abstract. Meeting, 13th International Conference on Defects-- Recognition, Imaging and Physics in Semiconductors. Symposium, 13th International ...

294

Soft x-ray microscopy - a powerful analytical tool to image magnetism down to fundamental length and times scales  

E-Print Network (OSTI)

of current third generation sources where due to themagnet source at a third generation X-ray synchrotron such

Fischer, Peter

2008-01-01T23:59:59.000Z

295

Effects of Sulfation Level on the Desulfation Behavior of Presulfated Pt-BaO/Al2O3 Lean NOx Trap Catalysts: A Combined H2 Temperature-Programmed Reaction, in Situ Sulfur K-Edge X-ray Absorption Near-Edge Spectroscopy, X-ray Photoelectron Spectroscopy, and Time-Resolved X-ray Diffraction Study  

SciTech Connect

Desulfation by hydrogen of presulfated Pt (2 wt %)-BaO(20 wt %)/Al{sub 2}O{sub 3} with various sulfur loading (S/Ba = 0.12, 0.31, and 0.62) were investigated by combining H{sub 2} temperature programmed reaction (TPRX), X-ray photoelectron spectroscopy (XPS), in situ sulfur K-edge X-ray absorption near-edge spectroscopy (XANES), and synchrotron time-resolved X-ray diffraction (TR-XRD) techniques. We find that the amount of H{sub 2}S desorbed during the desulfation in the H{sub 2} TPRX experiments is not proportional to the amount of initial sulfur loading. The results of both in situ sulfur K-edge XANES and TR-XRD show that at low sulfur loadings, sulfates were transformed to a BaS phase and remained in the catalyst rather than being removed as H{sub 2}S. On the other hand, when the deposited sulfur level exceeded a certain threshold (at least S/Ba = 0.31) sulfates were reduced to form H{sub 2}S, and the relative amount of the residual sulfide species in the catalyst was much less than at low sulfur loading. Unlike samples with high sulfur loading (e.g., S/Ba = 0.62), H{sub 2}O did not promote the desulfation for the sample with S/Ba of 0.12, implying that the formed BaS species originating from the reduction of sulfates at low sulfur loading are more stable to hydrolysis. The results of this combined spectroscopy investigation provide clear evidence to show that sulfates at low sulfur loadings are less likely to be removed as H{sub 2}S and have a greater tendency to be transformed to BaS on the material, leading to the conclusion that desulfation behavior of Pt-BaO/Al{sub 2}O{sub 3} lean NO{sub x} trap catalysts is markedly dependent on the sulfation levels.

Kim, D.H.; Hanson, J.; Szanyi, J.; Kwak, J.H.; Wang, X.; Hanson, J.C.; Engelhard, M.; and Peden, C.H.F.

2009-04-30T23:59:59.000Z

296

Materials Analysis by Soft x-ray Scanning Transmission X-ray ...  

Science Conference Proceedings (OSTI)

About this Abstract. Meeting, Materials Science & Technology 2013. Symposium, Optical and X-ray Imaging Techniques for Material Characterization.

297

X-ray Absorption and Diffraction Studies of the Mixed-phase State of (CrxV1-x)2O3  

Science Conference Proceedings (OSTI)

X-ray diffraction and vanadium x-ray absorption near-edge structure (XANES) data have been obtained for (V{sub 1-x}Cr{sub x}){sub 2}O{sub 3} samples containing several concentrations of Cr, crossing the metal-insulator transition boundary. For single-phase single-crystal samples our theoretical results are generally in good qualitative agreement with our experimental single-crystal XANES, for both crystal orientations relative to the incident-beam electric vector. However, an anomalous peak occurs for both orientations in the K pre-edge of the single-crystal sample containing 1.2% Cr, a paramagnetic insulator sample that is in the concentration regime corresponding to the room-temperature two-phase (coexistence) region of the phase diagram. Upon increasing the temperature of the 0.4% Cr powdered material to 400 K so that one enters the two-phase region of the phase diagram, a similar peak appears and then diminishes at 600 K. These results, as well as experiments done by others involving room-temperature and low-temperature XANES of a 1.1% Cr sample, suggest that this feature in the V pre-edge structure is associated with the appearance under some circumstances of a small amount of highly distorted VO{sub 6} octahedra in the interface region between coexisting metal and insulating phases. Finally, we find that, for the two-phase regime, the concentration ratio of the metal-to-insulating phase varies between different regions from a sample batch of uniform composition made by the skull melting method.

D Pease; A Frenkel; V Krayzman; T Huang; P Shanthakumar; J Budnick; P Metcalf; F Chudnovsky; E Stern

2011-12-31T23:59:59.000Z

298

Automated X-ray image annotation: single versus ensemble of support vector machines  

Science Conference Proceedings (OSTI)

Advances in the medical imaging technology has lead to an exponential growth in the number of digital images that needs to be acquired, analyzed, classified, stored and retrieved in medical centers. As a result, medical image classification and retrieval ...

Devrim Unay; Octavian Soldea; Sureyya Ozogur-Akyuz; Mujdat Cetin; Aytul Ercil

2009-09-01T23:59:59.000Z

299

Predicting Fracture Toughness of TRIP 800 using Phase Properties Characterized by In-Situ High Energy X-Ray Diffraction  

Science Conference Proceedings (OSTI)

TRansformation Induced Plasticity (TRIP) steel is a typical representative of 1st generation advanced high strength steel (AHSS) which exhibits a combination of high strength and excellent ductility due to its multiphase microstructure. In this paper, we study the crack propagation behavior and fracture resistance of a TRIP 800 steel using a microstructure-based finite element method with the various phase properties characterized by in-situ high energy Xray diffraction (HEXRD) technique. Uniaxial tensile tests on the notched TRIP 800 sheet specimens were also conducted, and the experimentally measured tensile properties and R-curves (Resistance curves) were used to calibrate the modeling parameters and to validate the overall modeling results. The comparison between the simulated and experimentally measured results suggests that the micromechanics based modeling procedure can well capture the overall complex crack propagation behaviors and the fracture resistance of TRIP steels. The methodology adopted here may be used to estimate the fracture resistance of various multiphase materials.

Soulami, Ayoub; Choi, Kyoo Sil; Liu, Wenning N.; Sun, Xin; Khaleel, Mohammad A.; Ren, Yang; Wang, Yan-Dong

2010-05-01T23:59:59.000Z

300

Crystallization and Preliminary X-ray Diffraction Analysis of Hemextin A: A Unique Anticoagulant Protein from Hemachatus haemachatus Venom  

Science Conference Proceedings (OSTI)

Hemextin A was isolated and purified from African Ringhals cobra (Hemachatus haemachatus). It is a three-finger toxin that specifically inhibits blood coagulation factor VIIa and clot formation and that also interacts with hemextin B to form a unique anticoagulant complex. Hemextin A was crystallized by the hanging-drop vapor-diffusion method by equilibration against 0.2 M ammonium acetate, 0.1 M sodium acetate trihydrate pH 4.6 and 30% PEG 4000 as the precipitating agent. The crystals belong to space group P2{sub 1}2{sub 1}2{sub 1}, with unit-cell parameters a = 49.27, b = 49.51, c = 57.87 {angstrom} and two molecules in the asymmetric unit. They diffracted to 1.5 {angstrom} resolution at beamline X25 at BNL.

Banerjee,Y.; Kumar, S.; Jobichen, C.; Kini, R.

2007-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "x-ray diffraction imaging" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


301

Lensless Imaging of Whole Biological Cells with Soft X-Rays  

NLE Websites -- All DOE Office Websites (Extended Search)

image (left) is focused through the cells and reveals internal structures. A scanning electron microscope image of the back of the cells (center) sees only their surfaces,...

302

Raman spectroscopy and x-ray diffraction of phase transitions in Cr2O3 to 61 GPa Sang-Heon Shim*  

E-Print Network (OSTI)

Radiation Laboratory SSRL using mono- chromatic x-ray beams ( 0.4959 Ã? at CHESS and 0.7277 Ã? at SSRL

Duffy, Thomas S.

303

Comparative Studies on C-coated and Uncoated LiFePO4 Cycling at Various Rates and Temperatures using Synchrotron Based in situ X-ray Diffraction  

DOE Green Energy (OSTI)

The structural changes of LiFePO{sub 4} and C-coated LiFePO{sub 4} during charging at various C-rates and temperatures are investigated using synchrotron based in situ X-ray diffraction technique. The XRD patterns collected during cycling show the structural evidence of the positive effects of carbon coating on LiFePO{sub 4} for the electrochemical performance improvements at different temperatures, especially at low temperatures. At -10 C, the C-coated LiFePO{sub 4} shows comparable capacities with the sample cycled at room temperature when cycled at C/5 rate with a slight shift of the plateau to a higher voltage during charging. The in situ XRD patterns collected simultaneously show a complete phase transformation from triphylite to heterosite. At -20 C, the C-coated LiFePO{sub 4} delivers 55.6% of its theoretical capacities at C/5 rate. However, the plateau in the charging curve becomes sloppy and shifts to a higher voltage. The in situ XRD patterns show that the phase transformation from triphylite to heterosite is not completed when charged to 4.5 V due to the larger polarization when charged at -20 C.

H Shin; K Nam; W Chang; B Cho; W Yoon; X Yang; K Chung

2011-12-31T23:59:59.000Z

304

Formation of deformation textures in face-centered-cubic materials studied by in-situ high-energy x-ray diffraction and self-consistent model.  

Science Conference Proceedings (OSTI)

The evolution of deformation textures in copper and a brass that are representative of fcc metals with different stacking fault energies (SFEs) during cold rolling is predicted using a self-consistent (SC) model. The material parameters used for describing the micromechanical behavior of each metal are determined from the high-energy X-ray (HEXRD) diffraction data. At small reductions, a reliable prediction of the evolution of the grain orientation distribution that is represented as the continuous increase of the copper and brass components is achieved for both metals when compared with the experimental textures. With increasing deformation, the model could characterize the textures of copper, i.e., the strengthening of the copper component, when dislocation slip is still the dominant mechanism. For a brass at moderate and large reductions, a reliable prediction of its unique feature of texture evolution, i.e., the weakening of the copper component and the strengthening of the brass component, could only be achieved when proper boundary conditions together with some specified slip/twin systems are considered in the continuum micromechanics mainly containing twinning and shear banding. The present investigation suggests that for fcc metals with a low SFE, the mechanism of shear banding is the dominant contribution to the texture development at large deformations.

Jia, N.; Nie, Z. H.; Ren, Y.; Peng, R. L.; Wang, Y. D.; Zhao, X.; X-Ray Science Division; Northeastern Univ.; Linkoping Univ.; Beijing Inst. of Tech.

2010-05-01T23:59:59.000Z

305

In-Situ Observations of Phase Transformations During Welding of 1045 Steel using Spatially Resolved and Time Resolved X-Ray Diffraction  

SciTech Connect

Synchrotron-based methods have been developed at Lawrence Livermore National Laboratory (LLNL) for the direct observation of microstructure evolution during welding. These techniques, known as spatially resolved (SRXRD) and time resolved (TRXRD) x-ray diffraction, allow in-situ experiments to be performed during welding and provide direct observations of high temperature phases that form under the intense thermal cycles that occur. This paper presents observations of microstructural evolution that occur during the welding of a medium carbon AISI 1045 steel, using SRXRD to map the phases that are present during welding, and TRXRD to dynamically observe transformations during rapid heating and cooling. SRXRD was further used to determine the influence of welding heat input on the size of the high temperature austenite region, and the time required to completely homogenize this region during welding. These data can be used to determine the kinetics of phase transformations under the steep thermal gradients of welds, as well as benchmark and verify phase transformation models.

Elmer, J; Palmer, T; DebRoy, T

2005-10-28T23:59:59.000Z

306

The T2 phase in the Nb-Si-B system studied by ab initio calculations and synchrotron X-ray diffraction  

Science Conference Proceedings (OSTI)

The solid solution based on Nb{sub 5}Si{sub 3} (Cr{sub 5}B{sub 3} structure type, D8{sub l}, tI32, I4/mcm, No140, a=6.5767 A, c=11.8967 A) in the Nb-Si-B system was studied from the structural and thermodynamic point of view both experimentally and by ab initio calculations. Rietveld refinement of powder X-ray synchrotron data allowed to determine the boron to silicon substitution mechanism and the structural parameters. Ab initio calculations of different ordered compounds and selected disordered alloys allowed to obtain in addition to the enthalpy of formation of the solution, substitution mechanism and structural parameters which are in excellent agreement with the experimental data. The stability of the phase is discussed. - Graphial abstract: Valence-charge electron localization function in the z=0 plane of the D8{sub l} structure for the ordered compound Nb{sub 5}SiB{sub 2}. Highlights: Black-Right-Pointing-Pointer Coupling between ab initio data and experimental results from synchrotron powder diffraction. Black-Right-Pointing-Pointer Excellent agreement between the two techniques for the site occupancies and internal coordinates. Black-Right-Pointing-Pointer Explanation of the phase stability up to Nb{sub 5}SiB{sub 2}.

Joubert, J.-M., E-mail: jean-marc.joubert@icmpe.cnrs.fr [Chimie Metallurgique des Terres Rares, Institut de Chimie et des Materiaux Paris-Est, CNRS, Universite Paris-Est, UMR 7182, 2-8 rue Henri Dunant, F-94320 Thiais, France. (France); Colinet, C. [Science et Ingenierie des Materiaux et Procedes, Grenoble INP, UJF, CNRS, 38402 Saint Martin d'Heres Cedex (France); Rodrigues, G. [Laboratorio de Materiais e Metalurgia, Instituto de Engenharia Mecanica, Universidade Federal de Itajuba, Av. BPS 1303, 37500-903 Itajuba-MG (Brazil); Mestrado Profissional em Materiais, Centro Universitario de Volta Redonda, Av. Paulo Erlei Alves Abrantes 1325, 27240-560 Volta Redonda-RJ (Brazil); Suzuki, P.A.; Nunes, C.A. [Departamento de Engenharia de Materiais, Escola de Engenharia de Lorena, Universidade de Sao Paulo, Caixa Posta 116, 12600-970 Lorena-SP (Brazil); Coelho, G.C. [Mestrado Profissional em Materiais, Centro Universitario de Volta Redonda, Av. Paulo Erlei Alves Abrantes 1325, 27240-560 Volta Redonda-RJ (Brazil); Departamento de Engenharia de Materiais, Escola de Engenharia de Lorena, Universidade de Sao Paulo, Caixa Posta 116, 12600-970 Lorena-SP (Brazil); Tedenac, J.-C. [Institut de Chimie Moleculaire et des Materiaux I.C.G., UMR-CNRS 5253, Universite Montpellier II, Place E. Bataillon, 34095 Montpellier Cedex 5 (France)

2012-06-15T23:59:59.000Z

307

Growth sequence and interface formation in the Fe/MgO/Fe(001) tunnel junction analyzed by surface x-ray diffraction  

Science Conference Proceedings (OSTI)

We present a surface x-ray diffraction study of the interface geometric structure in the Fe/MgO/Fe(001) magnetic tunnel junction (MTJ). While the lower MgO/Fe(001) interface is characterized by a substoichiometric FeO{sub x} (x=0.6{+-}0.1) layer in agreement with previous studies, growth of Fe on the MgO spacer and the upper Fe/MgO interface structure strongly depends on the preparation method. If 0.4 monolayers of Fe are initially deposited in ambient oxygen atmosphere (p=10{sup -7} mbar) followed by Fe deposition under ultrahigh-vacuum (UHV) conditions, structural coherence across the trilayer junction is observed. In this case, substoichiometric FeO{sub x} layers are present at both Fe/MgO interfaces corresponding to a symmetric MTJ structure. In contrast, lattice registry is not preserved if Fe deposition is carried out solely under UHV conditions. Our results might have important implications for the preparation of magnetic tunnel junctions optimized to achieve giant tunneling-magnetoresistance amplitudes.

Tusche, C.; Meyerheim, H. L.; Kirschner, J. [Max-Planck-Institut fuer Mikrostrukturphysik, Weinberg 2, D-06120 Halle (Germany); Jedrecy, N. [Institut des NanoSciences de Paris, Universites Paris 6 et 7 et CNRS-UMR 7588, 4 place Jussieu, F-75252 Paris Cedex 05 (France); Renaud, G. [CEA-Grenoble, 17 rue des Martyrs, F-38054 Grenoble (France)

2006-11-15T23:59:59.000Z

308

Externally controlled pressure and temperature microreactor for in situ x-ray diffraction, visual and spectroscopic reaction investigations under supercritical and subcritial conditions  

SciTech Connect

A microreactor has been developed for in situ, spectroscopic investigations of materials and reaction processes with full external pressure and temperature control from ambient conditions to 400 C and 310 bar. The sample chamber is in direct contact with an external manifold, whereby gases, liquids or fluids can be injected and their activities controlled prior to and under investigation conditions. The microreactor employs high strength, single crystal moissanite windows which allow direct probe beam interaction with a sample to investigate in situ reaction processes and other materials properties. The relatively large volume of the cell, along with full optical accessibility and external temperature and pressure control, make this reaction cell well suited for experimental investigations involving any combination of gas, fluid, and solid interactions. The microreactor's capabilities are demonstrated through an in situ x-ray diffraction study of the conversion of a meta-serpentine sample to magnesite under high pressure and temperature. Serpentine is one of the mineral candidates for the implementation of mineral carbonation, an intriguing carbon sequestration candidate technology.

Diefenbacher, J.; McKelvy, M.; Chizemeshya, A.V.; Wolf, G.H. (ASU)

2010-07-13T23:59:59.000Z

309

A combined solid-state NMR and synchrotron x-ray diffraction powder study on the structure of the antioxidant(+)-catechin 4.5 hydrate.  

DOE Green Energy (OSTI)

Analyses combining X-ray powder diffraction (XRD) and solid-state NMR (SSNMR) data can now provide crystal structures in challenging powders that are inaccessible by traditional methods. The flavonoid catechin is an ideal candidate for these methods, as it has eluded crystallographic characterization despite extensive study. Catechin was first described nearly two centuries ago, and its powders exhibit numerous levels of hydration. Here, synchrotron XRD data provide all heavy-atom positions in (+)-catechin 4.5-hydrate and establish the space group as C2. SSNMR data ({sup 13}C tensor and {sup 1}H/{sup 13}C correlation) complete the conformation by providing catechin's five OH hydrogen orientations. Since 1903, this phase has been erroneously identified as a 4.0 hydrate, but XRD and density data establish that this discrepancy is due to the facile loss of the water molecule located at a Wyckoff special position in the unit cell. A final improvement to heavy-atom positions is provided by a geometry optimization of bond lengths and valence angles with XRD torsion angles held constant. The structural enhancement in this final structure is confirmed by the significantly improved fit of computed {sup 13}C tensors to experimental data.

Harper, J. K.; Doebbler, J. A.; Jaccques, E.; Grant, D. M.; Von Dreele, R. B.; Univ. of Utah

2010-03-10T23:59:59.000Z

310

Imaging Wellbore Cement Degradation by Carbon Dioxide under Geologic Sequestration Conditions Using X?ray Computed Microtomography  

Science Conference Proceedings (OSTI)

ABSTRACT: X-ray microtomography (XMT), a nondestructive three-dimensional imaging technique, was applied to demonstrate its capability to visualize the mineralogical alteration and microstructure changes in hydrated Portland cement exposed to carbon dioxide under geologic sequestration conditions. Steel coupons and basalt fragments were added to the cement paste in order to simulate cement-steel and cement-rock interfaces. XMT image analysis showed the changes of material density and porosity in the degradation front (density: 1.98 g/cm3, porosity: 40%) and the carbonated zone (density: 2.27 g/cm3, porosity: 23%) after reaction with CO2- saturated water for 5 months compared to unaltered cement (density: 2.15 g/cm3, porosity: 30%). Three-dimensional XMT imaging was capable of displaying spatially heterogeneous alteration in cement pores, calcium carbonate precipitation in cement cracks, and preferential cement alteration along the cement-steel and cement-rock interfaces. This result also indicates that the interface between cement and host rock or steel casing is likely more vulnerable to a CO2 attack than the cement matrix in a wellbore environment. It is shown here that XMT imaging can potentially provide a new insight into the physical and chemical degradation of wellbore cement by CO2 leakage.

Jung, Hun Bok; Jansik, Danielle P.; Um, Wooyong

2013-01-01T23:59:59.000Z

311

Capabilities and limitations of Phase Contrast Imaging techniques with X-rays and neutrons  

E-Print Network (OSTI)

Phase Contrast Imaging (PCI) was studied with the goal of understanding its relevance and its requirements. Current literature does not provide insight on the effect of a relaxation in coherence requirements on the PCI ...

Damato, Antonio Leonardo

2009-01-01T23:59:59.000Z

312

SLAC National Accelerator Laboratory - SLAC X-rays Help Discover...  

NLE Websites -- All DOE Office Websites (Extended Search)

which pulses 120 times a second. In the instant before the intense X-rays destroy a nanocrystal, detectors record a flash of X-ray diffraction information. Finally, scientists use...

313

Effects of Fresnel fringes on TEM images of interfaces in X-ray multilayers  

Science Conference Proceedings (OSTI)

Fresnel fringe effects make assessment of interfacial structures from high-resolution TEM images of cross-sectional specimens difficult, producing different apparent structures in the images. Fresnel fringes have been observed in many TEM images of W/C, WC/C, Ru/C, and Mo/Si, multilayers. Visibility of these fringes depends on the thickness of the specimen and the defocus value. Contrast of the fringes becomes higher with increasing defocus. The effects of these fringes have been commonly over-looked in efforts of making quantitative interpretation of interfacial profiles. In this report, we present the observations of the Fresnel fringes in nanometer period Mo/Si, W/C, and WC/C multilayers in through-focus-series TEM images. Calculation of the Fresnel fringes of a Mo/Si multilayer using charge density approximation is used to illustrate the characteristics of the fringes from different interfacial structures. We find that the potential difference and the abruptness of the interfacial composition change are a strong function of the fringe contrast, while the fringes spacing depends more strongly on the thickness of the transition or interfacial layer.

Nguyen, Tai D.; O'Keefe, Michael A.; Kilaas, Roar; Gronsky, Ronald; Kortright, Jeffrey B.

1992-03-02T23:59:59.000Z

314

Oil-Well Cement and C3S Hydration Under High Pressure as Seen by In Situ X-Ray Diffraction, Temperatures ;= 80 degrees C with No Additives  

SciTech Connect

The hydration kinetics of a white cement and batches of both Class G and H oil-well cements were examined between 0 and 60 MPa, at {le}80 C, using in situ synchrotron X-ray diffraction. This gives a continuous measure of the C{sub 3}S (Ca{sub 3}SiO{sub 5}), CH (Ca(OH){sub 2}), C{sub 4}AF (Ca{sub 2}FeAlO{sub 5}), ettringite, and other phases in the hydrating slurries. Slurries prepared from single-phase C{sub 3}S; synthetic C{sub 4}AF, and gypsum; and white cement, synthetic C{sub 4}AF and gypsum were also examined. An increasing pressure enhanced the rate of hydration for all slurries. Analysis of the data, using a kinetic model, provided rate constants that were used to obtain activation volumes for C{sub 3}S hydration. For all the cement and C{sub 3}S slurries studied, similar activation volumes were obtained (average {Delta}V{double_dagger}{sup -}-35 cm{sup 3}/mol), indicating that the presence of cement phases other than C{sub 3}S has a modest influence on the pressure dependence of C{sub 3}S hydration. An alternative analysis, using the time at which 90% of the initial C{sub 3}S remained, gave similar activation volumes. Pressure accelerated the formation of ettringite from synthetic C{sub 4}AF in the presence of gypsum. However, in slurries containing cement, the pressure dependence of C{sub 3}S hydration plays a major role in determining the pressure dependence of ettringite formation.

Jupe, Andrew C.; Wilkinson, Angus P.; Funkhouser, Garry P. (Halliburton); (GIT)

2012-06-28T23:59:59.000Z

315

X-ray diffraction analysis and scanning micro-Raman spectroscopy of structural irregularities and strains deep inside the multilayered InGaN/GaN heterostructure  

SciTech Connect

High-resolution X-ray diffraction analysis and scanning confocal Raman spectroscopy are used to study the spatial distribution of strains in the In{sub x}Ga{sub 1-x}N/GaN layers and structural quality of these layers in a multilayered light-emitting diode structure produced by metal-organic chemical vapor deposition onto (0001)-oriented sapphire substrates. It is shown that elastic strains almost completely relax at the heterointerface between the thick GaN buffer layer and In{sub x}Ga{sub 1-x}N/GaN buffer superlattice. It is established that the GaN layers in the superlattice are in a stretched state, whereas the alloy layers are in a compressed state. In magnitude, the stretching strains in the GaN layers are lower than the compressive strains in the InGaN layers. It is shown that, as compared to the buffer layers, the layers of the superlattice contain a smaller number of dislocations and the distribution of dislocations is more randomly disordered. In micro-Raman studies on scanning through the thickness of the multilayered structure, direct evidence is obtained for the asymmetric gradient distributions of strains and crystal imperfections of the epitaxial nitride layers along the direction of growth. It is shown that the emission intensity of the In{sub x}Ga{sub 1-x}N quantum well is considerably (more than 30 times) higher than the emission intensity of the GaN barrier layers, suggesting the high efficiency of trapping of charge carriers by the quantum well.

Strelchuk, V. V., E-mail: Strelch@isp.kiev.ua; Kladko, V. P.; Avramenko, E. A.; Kolomys, O. F.; Safryuk, N. V.; Konakova, R. V. [National Academy of Sciences of Ukraine, Lashkaryov Institute of Semiconductor Physics (Ukraine); Yavich, B. S., E-mail: byavich@soptel.ru [ZAO Svetlana-Optoelectronics (Russian Federation); Valakh, M. Ya.; Machulin, V. F.; Belyaev, A. E. [National Academy of Sciences of Ukraine, Lashkaryov Institute of Semiconductor Physics (Ukraine)

2010-09-15T23:59:59.000Z

316

Hidden Superlattice in Tl2(SC6H4S) and Tl2(SeC6H4Se) Solved from Powder X-ray Diffraction  

SciTech Connect

The crystal structures of the isostructural title compounds poly[({mu}-benzene-1,4-dithiolato)dithallium], Tl{sub 2}(SC{sub 6}H{sub 4}S), and poly[({mu}-benzene-1,4-diselenolato)dithallium], Tl{sub 2}(SeC{sub 6}H{sub 4}Se), were solved by simulated annealing from high-resolution synchrotron X-ray powder diffraction. Rietveld refinements of an initial structure with one formula unit per triclinic cell gave satisfactory agreement with the data, but led to a structure with impossibly close non-bonded contacts. A disordered model was proposed to alleviate this problem, but an alternative supercell structure leads to slightly improved agreement with the data. The isostructural superlattice structures were confirmed for both compounds through additional data collection, with substantially better counting statistics, which revealed the presence of very weak superlattice peaks not previously seen. Overall, each structure contains Tl-S or Tl-Se two-dimensional networks, connected by phenylene bridges. The sulfur (or selenium) coordination sphere around each thallium is a highly distorted square pyramid or a 'see-saw' shape, depending upon how many Tl-S or Tl-Se interactions are considered to be bonds. In addition, the two compounds contain pairs of Tl{sup I} ions that interact through a closed-shell 'thallophilic' interaction: in the sulfur compound there are two inequivalent pairs of Tl atoms with Tl-Tl distances of 3.49 and 3.58 {angstrom}, while in the selenium compound those Tl-Tl interactions are at 3.54 and 3.63 {angstrom}.

K Stone; D Turner; M Singh; T Vaid; P Stephens

2011-12-31T23:59:59.000Z

317

X-Ray Diffraction Imaging of Improved Bulk Grown CdZnTe (211)  

Science Conference Proceedings (OSTI)

Accelerated Light Induced Degradation, ALID, for Monitoring of Defects in PV Silicon ... Silicon Solar Cells Evaluated by LBIC and Equivalent Circuit Model.

318

Evaluation of the geometric accuracy of surrogate-based gated VMAT using intrafraction kilovoltage x-ray images  

SciTech Connect

Purpose: To evaluate the geometric accuracy of beam targeting in external surrogate-based gated volumetric modulated arc therapy (VMAT) using kilovoltage (kV) x-ray images acquired during dose delivery. Methods: Gated VMAT treatments were delivered using a Varian TrueBeam STx Linac for both physical phantoms and patients. Multiple gold fiducial markers were implanted near the target. The reference position was created for each implanted marker, representing its correct position at the gating threshold. The gating signal was generated from the RPM system. During the treatment, kV images were acquired immediately before MV beam-on at every breathing cycle, using the on-board imaging system. All implanted markers were detected and their 3D positions were estimated using in-house developed software. The positioning error of a marker is defined as the distance of the marker from its reference position for each frame of the images. The overall error of the system is defined as the average over all markers. For the phantom study, both sinusoidal motion (1D and 3D) and real human respiratory motion was simulated for the target and surrogate. In the baseline case, the two motions were synchronized for the first treatment fraction. To assess the effects of surrogate-target correlation on the geometric accuracy, a phase shift of 5% and 10% between the two motions was introduced. For the patient study, intrafraction kV images of five stereotactic body radiotherapy (SBRT) patients were acquired for one or two fractions. Results: For the phantom study, a high geometric accuracy was achieved in the baseline case (average error: 0.8 mm in the superior-inferior or SI direction). However, the treatment delivery is prone to geometric errors if changes in the target-surrogate relation occur during the treatment: the average error was increased to 2.3 and 4.7 mm for the phase shift of 5% and 10%, respectively. Results obtained with real human respiratory curves show a similar trend. For a target with 3D motion, the technique is able to detect geometric errors in the left-right (LR) and anterior-posterior (AP) directions. For the patient study, the average intrafraction positioning errors are 0.8, 0.9, and 1.4 mm and 95th percentile errors are 1.7, 2.1, and 2.7 mm in the LR, AP, and SI directions, respectively. Conclusions: The correlation between external surrogate and internal target motion is crucial to ensure the geometric accuracy of surrogate-based gating. Real-time guidance based on kV x-ray images overcomes the potential issues in surrogate-based gating and can achieve accurate beam targeting in gated VMAT.

Li Ruijiang; Mok, Edward; Han, Bin; Koong, Albert; Xing Lei [Department of Radiation Oncology, Stanford University, Stanford, California 94305-5847 (United States)

2012-05-15T23:59:59.000Z

319

Earth Occultation Imaging Applied to BATSE -- Application to a Combined BATSE-GBM Survey of the Hard X-Ray Sky  

E-Print Network (OSTI)

A combined BATSE-GBM hard X-ray catalog is presented based on Earth Occultation Imaging applied to a reanalysis of BATSE data. An imaging approach has been developed for the reanalysis of Earth Occultation analysis of BATSE data. The standard occultation analysis depends on a predetermined catalog of potential sources, so that a real source not present in the catalog may induce systematic errors when source counts associated with an uncatalogued source are incorrectly attributed to catalog sources. The goal of the imaging analysis is to find a complete set of hard X-ray sources, including sources not in the original BATSE occultation catalog. Using the imaging technique, we have identified 15 known sources and 17 unidentified sources and added them to the BATSE occultation catalog. The resulting expanded BATSE catalog of sources observed during 1991-2000 is compared to the ongoing GBM survey.

Zhang, Yuan; Case, Gary; Ling, James; Wheaton, William

2013-01-01T23:59:59.000Z

320

Prospective-gated cardiac micro-CT imaging of free-breathing mice using carbon nanotube field emission x-ray  

Science Conference Proceedings (OSTI)

Purpose: Carbon nanotube (CNT) based field emission x-ray source technology has recently been investigated for diagnostic imaging applications because of its attractive characteristics including electronic programmability, fast switching, distributed source, and multiplexing. The purpose of this article is to demonstrate the potential of this technology for high-resolution prospective-gated cardiac micro-CT imaging. Methods: A dynamic cone-beam micro-CT scanner was constructed using a rotating gantry, a stationary mouse bed, a flat-panel detector, and a sealed CNT based microfocus x-ray source. The compact single-beam CNT x-ray source was operated at 50 KVp and 2 mA anode current with 100 {mu}mx100 {mu}m effective focal spot size. Using an intravenously administered iodinated blood-pool contrast agent, prospective cardiac and respiratory-gated micro-CT images of beating mouse hearts were obtained from ten anesthetized free-breathing mice in their natural position. Four-dimensional cardiac images were also obtained by gating the image acquisition to different phases in the cardiac cycle. Results: High-resolution CT images of beating mouse hearts were obtained at 15 ms temporal resolution and 6.2 lp/mm spatial resolution at 10% of system MTF. The images were reconstructed at 76 {mu}m isotropic voxel size. The data acquisition time for two cardiac phases was 44{+-}9 min. The CT values observed within the ventricles and the ventricle wall were 455{+-}49 and 120{+-}48 HU, respectively. The entrance dose for the acquisition of a single phase of the cardiac cycle was 0.10 Gy. Conclusions: A high-resolution dynamic micro-CT scanner was developed from a compact CNT microfocus x-ray source and its feasibility for prospective-gated cardiac micro-CT imaging of free-breathing mice under their natural position was demonstrated.

Cao Guohua; Burk, Laurel M.; Lee, Yueh Z.; Calderon-Colon, Xiomara; Sultana, Shabana; Lu Jianping; Zhou, Otto [Department of Physics and Astronomy, University of North Carolina, Chapel Hill, North Carolina 27599 (United States); Department of Physics and Astronomy, University of North Carolina, Chapel Hill, North Carolina 27599 and Department of Radiology, University of North Carolina, Chapel Hill, North Carolina 27599 (United States); Curriculum in Applied Sciences and Engineering, University of North Carolina, Chapel Hill, North Carolina 27599 (United States); Department of Physics and Astronomy, University of North Carolina, Chapel Hill, North Carolina 27599 (United States) and Curriculum in Applied Sciences and Engineering, University of North Carolina, Chapel Hill, North Carolina 27599 (United States); Department of Physics and Astronomy, University of North Carolina, Chapel Hill, North Carolina 27599 (United States); Curriculum in Applied Sciences and Engineering, University of North Carolina, Chapel Hill, North Carolina 27599 (United States) and Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, North Carolina 27599 (United States)

2010-10-15T23:59:59.000Z

Note: This page contains sample records for the topic "x-ray diffraction imaging" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


321

Instrument Series: Spectroscopy and Diffraction XPS Imaging  

NLE Websites -- All DOE Office Websites (Extended Search)

XPS Imaging XPS Imaging The X-ray photoelectron spectroscopy (XPS) imaging system provides fast, quantitative, real-time parallel imaging with highest resolution spectroscopy at all analysis areas. In addition, the system is equipped with temperature programmed desorption (TPD), ultraviolet photoelectron spectroscopy (UPS), ion scattering spectroscopy (ISS), a cluster/Ar + ion gun, and a five-axis automated stage with variable temperature sample environment at the analysis chamber. The system is also integrated with a radial distribution chamber (RDC), a full-size glove box, and a cold-stage at the sample introduction for air-sensitive, liquid-semisolid, biological and environmental sample transfers. In addition, the RDC has a simple sample transfer mechanism to the

322

In-line phase-contrast imaging of a biological specimen using a compact laser-Compton scattering-based x-ray source  

SciTech Connect

Laser-Compton scattering (LCS) x-ray sources have recently attracted much attention for their potential use at local medical facilities because they can produce ultrashort pulsed, high-brilliance, and quasimonochromatic hard x rays with a small source size. The feasibility of in-line phase-contrast imaging for a 'thick' biological specimens of rat lumbar vertebrae using the developed compact LCS-X in AIST was investigated for the promotion of clinical imaging. In the higher-quality images, anatomical details of the spinous processes of the vertebrae are more clearly observable than with conventional absorption radiography. The results demonstrate that phase-contrast radiography can be performed using LCS-X.

Ikeura-Sekiguchi, H.; Kuroda, R.; Yasumoto, M.; Toyokawa, H.; Koike, M.; Yamada, K. [National Institute of Advanced Industrial Science and Technology (AIST), Central 2-5, 1-1-1 Umezono, Tsukuba, Ibaraki 305-8568 (Japan); Sakai, F. [Sumitomo Heavy Industries, Ltd. (SHI), 2-1-1, Yatocho, Nishitokyo, Tokyo 188-8585 (Japan); Mori, K.; Maruyama, K. [Ibaraki Prefectural University of Health Sciences, 4669-2, Ami, Inashiki, Ibaraki 300-0394 (Japan); Oka, H.; Kimata, T. [St. Marianna University School of Medicine, 2-16-1, Sugao, Miyamae-ku, Kawasaki City 216-8512 (Japan)

2008-03-31T23:59:59.000Z

323

Development of a High Resolution X-Ray Imaging Crystal Spectrometer for Measurement of Ion-Temperature and Rotation-Velocity Profiles in Fusion Energy Research Plasmas  

SciTech Connect

A new imaging high resolution x-ray crystal spectrometer (XCS) has been developed to measure continuous profiles of ion temperature and rotation velocity in fusion plasmas. Following proof-of-principle tests on the Alcator C-Mod tokamak and the NSTX spherical tokamak, and successful testing of a new silicon, pixilated detector with 1MHz count rate capability per pixel, an imaging XCS is being designed to measure full profiles of Ti and v? on C-Mod. The imaging XCS design has also been adopted for ITER. Ion-temperature uncertainty and minimum measurable rotation velocity are calculated for the C-Mod spectrometer. The affects of x-ray and nuclear-radiation background on the measurement uncertainties are calculated to predict performance on ITER.

Hill, K W; Broennimann, Ch; Eikenberry, E F; Ince-Cushman, A; Lee, S G; Rice, J E; Scott, S

2008-02-27T23:59:59.000Z

324

The effect of exit beam phase aberrations on parallel beam coherent x-ray reconstructions.  

Science Conference Proceedings (OSTI)

Diffraction artifacts from imperfect x-ray windows near the sample are an important consideration in the design of coherent x-ray diffraction measurements. In this study, we used simulated and experimental diffraction patterns in two and three dimensions to explore the effect of phase imperfections in a beryllium window (such as a void or inclusion) on the convergence behavior of phasing algorithms and on the ultimate reconstruction. A predictive relationship between beam wavelength, sample size, and window position was derived to explain the dependence of reconstruction quality on beryllium defect size. Defects corresponding to this prediction cause the most damage to the sample exit wave and induce signature error oscillations during phasing that can be used as a fingerprint of experimental x-ray window artifacts. The relationship between x-ray window imperfection size and coherent x-ray diffractive imaging reconstruction quality explored in this work can play an important role in designing high-resolution in situ coherent imaging instrumentation and will help interpret the phasing behavior of coherent diffraction measured in these in situ environments.

Hruszkewycz, S. O.; Harder, R.; Xiao, X.; Fuoss, P. H. (Materials Science Division); ( XSD)

2010-12-01T23:59:59.000Z

325

The effect of exit beam phase aberrations on parallel beam coherent x-ray reconstructions  

Science Conference Proceedings (OSTI)

Diffraction artifacts from imperfect x-ray windows near the sample are an important consideration in the design of coherent x-ray diffraction measurements. In this study, we used simulated and experimental diffraction patterns in two and three dimensions to explore the effect of phase imperfections in a beryllium window (such as a void or inclusion) on the convergence behavior of phasing algorithms and on the ultimate reconstruction. A predictive relationship between beam wavelength, sample size, and window position was derived to explain the dependence of reconstruction quality on beryllium defect size. Defects corresponding to this prediction cause the most damage to the sample exit wave and induce signature error oscillations during phasing that can be used as a fingerprint of experimental x-ray window artifacts. The relationship between x-ray window imperfection size and coherent x-ray diffractive imaging reconstruction quality explored in this work can play an important role in designing high-resolution in situ coherent imaging instrumentation and will help interpret the phasing behavior of coherent diffraction measured in these in situ environments.

Hruszkewycz, S. O.; Fuoss, P. H. [Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Harder, R.; Xiao, X. [X-Ray Science Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States)

2010-12-15T23:59:59.000Z

326

Hard x-ray (>100 keV) imager to measure hot electron preheat for indirectly driven capsule implosions on the NIF  

Science Conference Proceedings (OSTI)

We have fielded a hard x-ray (>100 keV) imager with high aspect ratio pinholes to measure the spatially resolved bremsstrahlung emission from energetic electrons slowing in a plastic ablator shell during indirectly driven implosions at the National Ignition Facility. These electrons are generated in laser plasma interactions and are a source of preheat to the deuterium-tritium fuel. First measurements show that hot electron preheat does not limit obtaining the fuel areal densities required for ignition and burn.

Doeppner, T.; Dewald, E. L.; Divol, L.; Thomas, C. A.; Burns, S.; Celliers, P. M.; Izumi, N.; LaCaille, G.; McNaney, J. M.; Prasad, R. R.; Robey, H. F.; Glenzer, S. H.; Landen, O. L. [Lawrence Livermore National Laboratory, Livermore, California 94551 (United States); Kline, J. L. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

2012-10-15T23:59:59.000Z

327

4D Functional Materials Science with X-ray Microscopy  

Science Conference Proceedings (OSTI)

Ultrafast Electron Diffraction Studies of Lattice Dynamics in Thin Bismuth Films · Understanding Fatigue and Corrosion-Fatigue Behavior by In Situ 3D X-ray ...

328

Bibliography of NRL Works on X-Ray Fluorescence Authored ...  

Science Conference Proceedings (OSTI)

... LS Birks, and EJ Brooks, "Grain-Boundary Diffusion of Zinc in Copper ... 111 J. Gilfrich, "X-Ray Diffraction Studies on the Titanium-Nickel System," in ...

2012-10-05T23:59:59.000Z

329

The Center for X-ray Optics - Now hiring engineers. Apply Today.  

NLE Websites -- All DOE Office Websites (Extended Search)

Database Nanomagnetism X-Ray Microscopy EUV Lithography EUV Mask Database Nanomagnetism X-Ray Microscopy EUV Lithography EUV Mask Imaging Reflectometry Zoneplate Lenses Coherent Optics Nanofabrication Optical Coatings Engineering Education Careers Publications Contact LBNL-Logo The Center for X-Ray Optics is a multi-disciplined research group within Lawrence Berkeley National Laboratory's (LBNL) Materials Sciences Division (MSD). Notice to users. Precision Engineering Building the tools that make nanoscience possible. A high-precision stage fabricated by CXRO's Instrument Fabrication Facility Zone plates Diffractive lenses for a new generation of x-ray beamlines. SEM image of a zoneplate fabricated by CXRO Interferometry Wavefront control with sub-angstrom sensitivity Null interferogram, in preparation for EUV metrology of the SEMATECH Berkeley Microfield Exposure Tool (MET)

330

X-Ray Topography  

Science Conference Proceedings (OSTI)

Sep 17, 2009 ... Stress Mapping Analysis by Ray Tracing (SMART): A New Technique ... technique of synchrotron X-ray topography, where a grid made out of ...

331

Flight Performance of an advanced CZT Imaging Detector in a Balloon-borne Wide-Field Hard X-ray Telescope - ProtoEXIST1  

E-Print Network (OSTI)

We successfully carried out the first high-altitude balloon flight of a wide-field hard X-ray coded-aperture telescope ProtoEXIST1, which was launched from the Columbia Scientific Balloon Facility at Ft. Sumner, New Mexico on October 9, 2009. ProtoEXIST1 is the first implementation of an advanced CdZnTe (CZT) imaging detector in our ongoing program to establish the technology required for next generation wide-field hard X-ray telescopes. The CZT detector plane in ProtoEXIST1 consists of an 8 x 8 array of closely tiled 2 cm x 2 cm x 0.5 cm thick pixellated CZT crystals, each with 8 x 8 pixels, covering a 256 cm^2 active area with 2.5 mm pixels. A tungsten mask, mounted at 90 cm above the detector provides shadowgrams of X-ray sources in the 30 - 600 keV band for imaging, allowing a fully coded field of view of 9 Deg x 9 Deg with an angular resolution of 20 arcmin. To reduce the background radiation, the detector is surrounded by semi-graded (Pb/Sn/Cu) passive shields on the four sides all the way to the mask. ...

Hong, J; Grindlay, J; Barthelemy, S; Baker, R; Garson, A; Krawczynski, H; Apple, J; Cleveland, W H

2011-01-01T23:59:59.000Z

332

Quantitative characterization of the protein contents of the exocrine pancreatic acinar cell by soft x-ray microscopy and advanced digital imaging methods  

Science Conference Proceedings (OSTI)

The study of the exocrine pancreatic acinar cell has been central to the development of models of many cellular processes, especially of protein transport and secretion. Traditional methods used to examine this system have provided a wealth of qualitative information from which mechanistic models have been inferred. However they have lacked the ability to make quantitative measurements, particularly of the distribution of protein in the cell, information critical for grounding of models in terms of magnitude and relative significance. This dissertation describes the development and application of new tools that were used to measure the protein content of the major intracellular compartments in the acinar cell, particularly the zymogen granule. Soft x-ray microscopy permits image formation with high resolution and contrast determined by the underlying protein content of tissue rather than staining avidity. A sample preparation method compatible with x-ray microscopy was developed and its properties evaluated. Automatic computerized methods were developed to acquire, calibrate, and analyze large volumes of x-ray microscopic images of exocrine pancreatic tissue sections. Statistics were compiled on the protein density of several organelles, and on the protein density, size, and spatial distribution of tens of thousands of zymogen granules. The results of these measurements, and how they compare to predictions of different models of protein transport, are discussed.

Loo Jr., Billy W.

2000-06-09T23:59:59.000Z

333

Application of PILATUS II Detector Modules for High Resolution X-Ray Imaging Crystal Spectrometers on the Alcator C-Mod Tokamak  

Science Conference Proceedings (OSTI)

A new type of X-ray imaging crystal spectrometer for Doppler measurements of the radial profiles of the ion temperature and plasma rotation velocity in tokamak plasmas is presently being developed in a collaboration between various laboratories. The spectrometer will consist of a spherically bent crystal and a two-dimensional position sensitive detector; and it will record temporally and spatially resolved X-ray line spectra from highly-charged ions. The detector must satisfy challenging requirements with respect to count rate and spatial resolution. The paper presents the results from a recent test of a PILATUS II detector module on Alcator C-Mod, which demonstrate that the PILATUS II detector modules will satisfy these requirements.

M.L. Bitter, Ch. Borennimann, E.F. Eikenberry, K.W. Hill, A. Ince-Chushman, S.G. Lee, J.E. Rice, and S. Scott.

2007-07-23T23:59:59.000Z

334

X-ray beamsplitter  

DOE Patents (OSTI)

An x-ray beamsplitter which splits an x-ray beam into two coherent parts by reflecting and transmitting some fraction of an incident beam has applications for x-ray interferometry, x-ray holography, x-ray beam manipulation, and x-ray laser cavity output couplers. The beamsplitter is formed of a wavelength selective multilayer thin film supported by a very thin x-ray transparent membrane. The beamsplitter resonantly transmits and reflects x-rays through thin film interference effects. A thin film is formed of 5-50 pairs of alternate Mo/Si layers with a period of 20-250 A. The support membrane is 10-200 nm of silicon nitride or boron nitride. The multilayer/support membrane structure is formed across a window in a substrate by first forming the structure on a solid substrate and then forming a window in the substrate to leave a free-standing structure over the window.

Ceglio, Natale M. (Livermore, CA); Stearns, Daniel S. (Mountain View, CA); Hawryluk, Andrew M. (Modesto, CA); Barbee, Jr., Troy W. (Palo Alto, CA)

1989-01-01T23:59:59.000Z

335

Chandra ACIS Survey of M33 (ChASeM33): X-ray Imaging Spectroscopy of M33SNR21, the brightest X-ray Supernova Remnant in M33  

E-Print Network (OSTI)

We present and interpret new X-ray data for M33SNR21, the brightest X-ray supernova remnant (SNR) in M33. The SNR is in seen projection against (and appears to be interacting with) the bright Hii region NGC592. Data for this source were obtained as part of the Chandra ACIS Survey of M33 (ChASeM33) 1

Terrance J. Gaetz; William P. Blair; John P. Hughes; P. Frank Winkler; Knox S. Long; Thomas G; Benjamin Williams; Richard J. Edgar; Parviz Ghavamian; Paul P. Plucinsky; Manami Sasaki; Robert P. Kirshner; Miguel Avillez; Dieter Breitschwerdt

2007-01-01T23:59:59.000Z

336

X-ray generator  

DOE Patents (OSTI)

Apparatus and method for producing coherent secondary x-rays that are controlled as to direction by illuminating a mixture of high z and low z gases with an intense burst of primary x-rays. The primary x-rays are produced with a laser activated plasma, and these x-rays strip off the electrons of the high z atoms in the lasing medium, while the low z atoms retain their electrons. The neutral atoms transfer electrons to highly excited states of the highly striped high z ions giving an inverted population which produces the desired coherent x-rays. In one embodiment, a laser, light beam provides a laser spark that produces the intense burst of coherent x-rays that illuminates the mixture of high z and low z gases, whereby the high z atoms are stripped while the low z ones are not, giving the desired mixture of highly ionized and neutral atoms. To this end, the laser spark is produced by injecting a laser light beam, or a plurality of beams, into a first gas in a cylindrical container having an adjacent second gas layer co-axial therewith, the laser producing a plasma and the intense primary x-rays in the first gas, and the second gas containing the high and low atomic number elements for receiving the primary x-rays, whereupon the secondary x-rays are produced therein by stripping desired ions in a neutral gas and transfer of electrons to highly excited states of the stripped ions from the unionized atoms. Means for magnetically confining and stabilizing the plasma are disclosed for controlling the direction of the x-rays.

Dawson, John M. (Los Angeles, CA)

1976-01-01T23:59:59.000Z

337

Analyzing the growth of In{sub x}Ga{sub 1-x}N/GaN superlattices in self-induced GaN nanowires by x-ray diffraction  

Science Conference Proceedings (OSTI)

Self-induced GaN nanowires are grown by plasma-assisted molecular beam epitaxy, with In{sub x}Ga{sub 1-x}N quantum wells inserted to form an axial superlattice. From the {omega}-2{theta} scans of a laboratory x-ray diffraction experiment, we obtain the superlattice period, the thickness of the quantum wells, and the In content in this layer. The axial growth rate of the In{sub x}Ga{sub 1-x}N quantum wells is significantly enhanced, which we attribute to increased Ga diffusion along the nanowire sidewalls in the presence of In.

Woelz, M.; Kaganer, V. M.; Brandt, O.; Geelhaar, L.; Riechert, H.

2011-06-27T23:59:59.000Z

338

An iterative three-dimensional electron density imaging algorithm using uncollimated Compton scattered x rays from a polyenergetic primary pencil beam  

Science Conference Proceedings (OSTI)

X-ray film-screen mammography is currently the gold standard for detecting breast cancer. However, one disadvantage is that it projects a three-dimensional (3D) object onto a two-dimensional (2D) image, reducing contrast between small lesions and layers of normal tissue. Another limitation is its reduced sensitivity in women with mammographically dense breasts. Computed tomography (CT) produces a 3D image yet has had a limited role in mammography due to its relatively high dose, low resolution, and low contrast. As a first step towards implementing quantitative 3D mammography, which may improve the ability to detect and specify breast tumors, we have developed an analytical technique that can use Compton scatter to obtain 3D information of an object from a single projection. Imaging material with a pencil beam of polychromatic x rays produces a characteristic scattered photon spectrum at each point on the detector plane. A comparable distribution may be calculated using a known incident x-ray energy spectrum, beam shape, and an initial estimate of the object's 3D mass attenuation and electron density. Our iterative minimization algorithm changes the initially arbitrary electron density voxel matrix to reduce regular differences between the analytically predicted and experimentally measured spectra at each point on the detector plane. The simulated electron density converges to that of the object as the differences are minimized. The reconstruction algorithm has been validated using simulated data produced by the EGSnrc Monte Carlo code system. We applied the imaging algorithm to a cylindrically symmetric breast tissue phantom containing multiple inhomogeneities. A preliminary ROC analysis scores greater than 0.96, which indicate that under the described simplifying conditions, this approach shows promise in identifying and localizing inhomogeneities which simulate 0.5 mm calcifications with an image voxel resolution of 0.25 cm and at a dose comparable to mammography.

Van Uytven, Eric; Pistorius, Stephen; Gordon, Richard [Department of Physics and Astronomy, University of Manitoba, Winnipeg, Manitoba R3T 2N2 (Canada) and Medical Physics, CancerCare Manitoba, 675 McDermot Ave., Winnipeg, Manitoba, R3A 1R9 (Canada); Department of Physics and Astronomy, University of Manitoba, Winnipeg, Manitoba R3T 2N2 (Canada); Medical Physics, CancerCare Manitoba, 675 McDermot Ave., Winnipeg, Manitoba R3A 1R9 (Canada) and Department of Radiology, University of Manitoba, HSC Room GA216, 820 Sherbrook Street, Winnipeg, Manitoba R3A 1R9 (Canada); Department of Radiology, University of Manitoba, HSC Room GA216, 820 Sherbrook Street, Winnipeg, Manitoba R3A 1R9 (Canada) and Department of Electrical and Computer Engineering, University of Manitoba, HSC Room GA216, 820 Sherbrook Street, Winnipeg, Manitoba R3A 1R9 (Canada)

2007-01-15T23:59:59.000Z

339

Introduction to Neutron and X-Ray Scattering  

NLE Websites -- All DOE Office Websites (Extended Search)

Scattering Studies of Thin Scattering Studies of Thin Polymer Films Introduction to Neutron and X-Ray Scattering Sunil K. Sinha UCSD/LANL Acknowledgements: Prof. R.Pynn( Indiana U.) Prof. M.Tolan (U. Dortmund) Wilhelm Conrad Röntgen 1845-1923 1895: Discovery of X-Rays 1901 W. C. Röntgen in Physics for the discovery of x-rays. 1914 M. von Laue in Physics for x-ray diffraction from crystals. 1915 W. H. Bragg and W. L. Bragg in Physics for crystal structure determination. 1917 C. G. Barkla in Physics for characteristic radiation of elements. 1924 K. M. G. Siegbahn in Physics for x-ray spectroscopy. 1927 A. H. Compton in Physics for scattering of x-rays by electrons. 1936 P. Debye in Chemistry for diffraction of x-rays and electrons in gases.

340

Comparison of Unmonochromatized Synchrotron Radiation and Conventional X-rays in the Imaging of Mammographic Phantom and Human Breast Specimens: A Preliminary Result  

E-Print Network (OSTI)

A simple imaging setup based on the principle of coherence-based contrast X-ray imaging with unmonochromatized synchrotron radiation was used for studying mammographic phantom and human breast specimens. The use of unmonochromatized synchrotron radiation simplifies the instrumentation, decreases the cost and makes the procedure simpler and potentially more suitable for clinical applications. The imaging systems consisted of changeable silicon wafer attenuators, a tungsten slit system, a CdWO4 scintillator screen, a CCD (Charge Coupled Device) camera coupled to optical magnification lenses, and a personal computer. In preliminary studies, a spatial resolution test pattern and glass capillary filled with air bubbles were imaged to evaluate the resOolution characteristics and coherence-based contrast enhancement. Both the spatial resolution and image quality of the proposed system

Haijo Jung; Hee-joung Kim; Eun-kyung Kim; Jin-o Hong; Jung Ho Je; Yeukuang Hwu; Wen-li Tsai; Giorgio Magaritondo; Hyung-sik Yoo

2004-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "x-ray diffraction imaging" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


341

Scanning Transmission X-ray Microscopy: Applications in Atmospheric Aerosol Research  

E-Print Network (OSTI)

G. R. et al. Scanning transmission X-ray microscopy: A newwith the scanning transmission X-ray microscope at BESSY II.T. et al. Scanning transmission X-ray microscopy imaging of

Moffet, Ryan C.

2011-01-01T23:59:59.000Z

342

Novel motor design for rotating anode x-ray tubes operating in the fringe field of a magnetic resonance imaging system  

SciTech Connect

Purpose: Using hybrid x-ray/MR (XMR) systems for image guidance during interventional procedures could enhance the diagnosis and treatment of neurologic, oncologic, cardiovascular, and other disorders. The authors propose a close proximity hybrid system design in which a C-arm fluoroscopy unit is placed immediately adjacent to the solenoid magnet of a MR system with a minimum distance of 1.2 m between the x-ray and MR imaging fields of view. Existing rotating anode x-ray tube designs fail within MR fringe field environments because the magnetic fields alter the electron trajectories in the x-ray tube and act as a brake on the induction motor, reducing the rotation speed of the anode. In this study the authors propose a novel motor design that avoids the anode rotation speed reduction. Methods: The proposed design replaces the permanent magnet stator found in brushed dc motors with the radial component of the MR fringe field. The x-ray tube is oriented such that the radial component of the MR fringe field is orthogonal to the cathode-anode axis. Using a feedback position sensor and the support bearings as electrical slip rings, the authors use electrical commutation to eliminate the need for mechanical brushes and commutators. A vacuum compatible prototype of the proposed motor design was assembled, and its performance was evaluated at various operating conditions. The prototype consisted of a 3.1 in. diameter anode rated at 300 kHU with a ceramic rotor that was 5.6 in. in length and had a 2.9 in. diameter. The material chosen for all ceramic components was MACOR, a machineable glass ceramic developed by Corning Inc. The approximate weight of the entire assembly was 1750 g. The maximum rotation speed, angular acceleration, and acceleration time of the motor design were investigated, as well as the dependence of these parameters on rotor angular offset, magnetic field strength, and field orientation. The resonance properties of the authors' assembly were also evaluated to determine its stability during acceleration, and a pulse width modulation algorithm was implemented to control the rotation speed of the motor. Results: At a magnetic flux density of 41 mT orthogonal to the axis of rotation (on the lower end of the expected flux density in the MR suite) the maximum speed of the motor was found to be 5150 revolutions per minute (rpm). The acceleration time necessary to reach 3000 rpm was found to be approximately 10 s at 59 mT. The resonance frequency of the assembly with the anode attached was 1310 rpm (21.8 Hz) which is far below the desired operating speeds. Pulse width modulation provides an effective method to control the speed of the motor with a resolution of 100 rpm. Conclusions: The proposed design can serve as a direct replacement to the conventional induction motor used in rotating anode x-ray tubes. It does not suffer from a reduced rotation speed when operating in a MR environment. The presence of chromic steel bearings in the prototype prevented testing at the higher field strengths, and future iterations of the design could eliminate this shortcoming. The prototype assembly demonstrates proof of concept of the authors' design and overcomes one of the major obstacles for a MR compatible rotating anode x-ray tube.

Lillaney, Prasheel; Pelc, Norbert [Department of Radiology, Stanford University, Stanford, California 94305 and Department of Bioengineering, Stanford University, Stanford, California 94305 (United States); Shin Mihye [Department of Radiology, Stanford University, Stanford, California 94305 and Department of Mechanical Engineering, Stanford University, Stanford, California 94305 (United States); Hinshaw, Waldo; Fahrig, Rebecca [Department of Radiology, Stanford University, Stanford, California 94305 (United States); Bennett, N. Robert [Department of Radiology, Stanford University, Stanford, California 94305 and Qualcomm MEMS Technologies, San Jose, California 95134 (United States)

2013-02-15T23:59:59.000Z

343

Gamma Radiation & X-Rays  

NLE Websites -- All DOE Office Websites (Extended Search)

Gamma Radiation and X-Rays 1. Gamma radiation and X-rays are electromagnetic radiation like visible light, radio waves, and ultraviolet light. These electromagnetic radiations...

344

Spatial Imaging And Speciation of Lead in the Accumulator Plant Sedum Alfredii By Microscopically Focused Synchrotron X-Ray Investigation  

Science Conference Proceedings (OSTI)

Sedum alfredii (Crassulaceae), a species native to China, has been characterized as a Zn/Cd cohyperaccumulator and Pb accumulator though the mechanisms of metal tolerance and accumulation are largely unknown. Here, the spatial distribution and speciation of Pb in tissues of the accumulator plant was investigated using synchrotron-based X-ray microfluorescence and powder Extended X-ray absorption fine structure (EXAFS) spectroscopy. Lead was predominantly restricted to the vascular bundles of both leaf and stem of the accumulator. Micro-XRF analysis revealed that Pb distributed predominantly within the areas of vascular bundles, and a positive correlation between the distribution patterns of S and Pb was observed. The dominant chemical form of Pb (>60%) in tissues of both accumulating (AE) and nonaccumulating ecotype (NAE) S. alfredii was similar to prepared Pb-cell wall compounds. However, the percentage of the Pb-cell wall complex is lower in the stem and leaf of AE, and a small amount of Pb appeared to be associated with SH-compounds. These results suggested a very low mobility of Pb out of vascular bundles, and that the metal is largely retained in the cell walls during transportation in plants of S. alfredii.

Tian, S.; Lu, L.; Yang, X.; Webb, S.M.; Du, Y.; Brown, P.H.; /SLAC

2012-08-23T23:59:59.000Z

345

Ray tracing flux calculation for the small and wide angle x-ray scattering diffraction station at the SESAME synchrotron radiation facility  

SciTech Connect

The calculation for the optics of the synchrotron radiation small and wide angle x-ray scattering beamline, currently under construction at SESAME is described. This beamline is based on a cylindrically bent germanium (111) single crystal with an asymmetric cut of 10.5 deg., followed by a 1.2 m long rhodium coated plane mirror bent into a cylindrical form. The focusing properties of bent asymmetrically cut crystals have not yet been studied in depth. The present paper is devoted to study of a particular application of a bent asymmetrically cut crystal using ray tracing simulations with the SHADOW code. These simulations show that photon fluxes of order of 1.09x10{sup 11} photons/s will be available at the experimental focus at 8.79 keV. The focused beam dimensions will be 2.2 mm horizontal full width at half maximum (FWHM) by 0.12 mm vertical (FWHM).

Salah, Wa'el [Synchrotron-light for Experimental Science and Application in the Middle East (SESAME), P.O. Box 7, Allan 19252 (Jordan); Department of Physics, The Hashemite University, Zarqa 13115 (Jordan); Sanchez del Rio, M. [European Synchrotron Radiation Facility, Bp 220, 38043 Grenoble Cedex (France); Hoorani, H. [Synchrotron-light for Experimental Science and Application in the Middle East (SESAME), P.O. Box 7, Allan 19252 (Jordan)

2009-09-15T23:59:59.000Z

346

The structural properties of the multi-layer graphene/4H-SiC(000¯1) system as determined by Surface X-ray Diffraction  

E-Print Network (OSTI)

We present a structural analysis of the multi-layer graphene-4HSiC(000¯1) system using Surface X-Ray Reflectivity. We show for the first time that graphene films grown on the C-terminated (000¯1) surface have a graphene-substrate bond length that is very short (1.62?A). The measured distance rules out a weak Van der Waals interaction to the substrate and instead indicates a strong bond between the first graphene layer and the bulk as predicted by ab-initio calculations. The measurements also indicate that multi-layer graphene grows in a near turbostratic mode on this surface. This result may explain the lack of a broken graphene symmetry inferred from conduction

J. Hass; R. Feng; J. E. Millán-otoya; X. Li; M. Sprinkle; P. N. First; C. Berger; W. A. De Heer; E. H. Conrad

2007-01-01T23:59:59.000Z

347

X-ray phase contrast imaging of biological specimens with femtosecond pulses of betatron radiation from a compact laser plasma wakefield accelerator  

Science Conference Proceedings (OSTI)

We show that x-rays from a recently demonstrated table top source of bright, ultrafast, coherent synchrotron radiation [Kneip et al., Nat. Phys. 6, 980 (2010)] can be applied to phase contrast imaging of biological specimens. Our scheme is based on focusing a high power short pulse laser in a tenuous gas jet, setting up a plasma wakefield accelerator that accelerates and wiggles electrons analogously to a conventional synchrotron, but on the centimeter rather than tens of meter scale. We use the scheme to record absorption and phase contrast images of a tetra fish, damselfly and yellow jacket, in particular highlighting the contrast enhancement achievable with the simple propagation technique of phase contrast imaging. Coherence and ultrafast pulse duration will allow for the study of various aspects of biomechanics.

Kneip, S. [Blackett Laboratory, Imperial College London, London SW7 2AZ (United Kingdom); Center for Ultrafast Optical Science, University of Michigan, Ann Arbor 48109 (United States); McGuffey, C.; Dollar, F.; Chvykov, V.; Kalintchenko, G.; Krushelnick, K.; Maksimchuk, A.; Mangles, S. P. D.; Matsuoka, T.; Schumaker, W.; Thomas, A. G. R.; Yanovsky, V. [Center for Ultrafast Optical Science, University of Michigan, Ann Arbor 48109 (United States); Bloom, M. S.; Najmudin, Z.; Palmer, C. A. J.; Schreiber, J. [Blackett Laboratory, Imperial College London, London SW7 2AZ (United Kingdom)

2011-08-29T23:59:59.000Z

348

2-20 ns interframe time 2-frame 6.151 keV x-ray imaging on the recently upgraded Z Accelerator: A progress report  

SciTech Connect

When used for the production of an x-ray imaging backlighter source on Sandia National Laboratories' recently upgraded 26 MA Z Accelerator, the terawatt-class, multikilojoule, 526.57 nm Z-Beamlet laser (ZBL) [P. K. Rambo et al., Appl. Opt. 44, 2421 (2005)], in conjunction with the 6.151 keV (1s{sup 2}-1s2p triplet line of He-like Mn) curved-crystal imager [D. B. Sinars et al., Rev. Sci. Instrum. 75, 3672 (2004); G. R. Bennett et al., Rev. Sci. Instrum. 77, 10E322 (2006)], is capable of providing a high quality x radiograph per Z shot for inertial confinement fusion (ICF), complex hydrodynamics, and other high-energy-density physics experiments. For example, this diagnostic has recently afforded microgram-scale mass perturbation measurements on an imploding ignition-scale 1 mg ICF capsule [G. R. Bennett et al., Phys. Rev. Lett. 99, 205003 (2007)], where the perturbation was initiated by a surrogate deuterium-tritium (DT) fuel fill tube. Using an angle-time multiplexing technique, ZBL now has the capability to provide two spatially and temporally separated foci in the Z chamber, allowing 'two-frame' imaging to be performed, with an interframe time range of 2-20 ns. This multiplexing technique allows the full area of the four-pass amplifiers to be used for the two pulses, rather than split the amplifiers effectively into two rectangular sections, with one leg delayed with respect to the other, which would otherwise double the power imposed onto the various optics thereby halving the damage threshold, for the same irradiance on target. The 6.151 keV two frame technique has recently been used to image imploding wire arrays, using a 7.3 ns interframe time. The diagnostic will soon be converted to operate with p-rather than s-polarized laser light for enhanced laser absorption in the Mn foil, plus other changes (e.g., operation at the possibly brighter 6.181 keV Mn 1s{sup 2}-1s2p singlet line), to increase x-ray yields. Also, a highly sensitive inline multiframe ultrafast (1 ns gate time) digital x-ray camera is being developed [G. R. Bennett et al., Rev. Sci. Instrum. 77, 10E322 (2006)] to extend the system to 'four-frame' and markedly improve the signal-to-noise ratio. [At present, time-integrating Fuji BAS-TR2025 image plate (scanned with a Fuji BAS-5000 device) forms the time-integrated image-plane detector.].

Bennett, G. R.; Smith, I. C.; Shores, J. E.; Sinars, D. B.; Robertson, G.; Atherton, B. W.; Jones, M. C.; Porter, J. L. [Sandia National Laboratories, P.O. Box 5800, Albuquerque, New Mexico 87185-1193 (United States)

2008-10-15T23:59:59.000Z

349

X-ray Scattering Reveals Unusual Growth of Lead on Silicon  

NLE Websites -- All DOE Office Websites (Extended Search)

X-ray Scattering Reveals Unusual Growth of Lead on Silicon X-ray Scattering Reveals Unusual Growth of Lead on Silicon Most thin films grow on substrates in only three ways: layer by layer, formation of atomic islands, or layers followed by islands. The particular growth mode that a given material will follow crucially depends on the relative magnitudes of the surface energy of the film versus the interfacial energy of the film on the substrate. Recently, a team of researchers from the University of Illinois, Academica Sinica in Taiwan, Georgia Tech, and the City University of Hong Kong has discovered a remarkable anomaly. By means of real-time x-ray scattering measurements, the researchers found that lead films grown on silicon adopt a completely novel pattern of growth. X-ray diffraction images taken with a CCD camera during growth of Pb films on Si(111). The interference fringes yield information about island height and layer thickness. Fig. 1. X-ray diffraction images taken with a CCD camera during growth of Pb films on Si(111). The interference fringes yield information about island height and layer thickness.

350

Chandra ACIS Survey of M33 (ChASeM33): X-ray Imaging Spectroscopy of M33SNR21, the Brightest X-ray Supernova Remnant in M33  

E-Print Network (OSTI)

We present and interpret new X-ray data for M33SNR21, the brightest X-ray supernova remnant (SNR) in M33. The SNR is in seen projection against (and appears to be interacting with) the bright HII region NGC592. Data for this source were obtained as part of the Chandra ACIS Survey of M33 (ChASeM33) Very Large Project. The nearly on-axis Chandra data resolve the SNR into a ~5" diameter (20 pc at our assumed M33 distance of 817+/-58 kpc) slightly elliptical shell. The shell is brighter in the east, which suggests that it is encountering higher density material in that direction. The optical emission is coextensive with the X-ray shell in the north, but extends well beyond the X-ray rim in the southwest. Modeling the X-ray spectrum with an absorbed sedov model yields a shock temperature of 0.46(+0.01,-0.02) keV, an ionization timescale of n_e t = $2.1 (+0.2,-0.3) \\times 10^{12}$ cm$^{-3}$ s, and half-solar abundances (0.45 (+0.12, -0.09)). Assuming Sedov dynamics gives an average preshock H density of 1.7 +/- 0.3 cm$^{-3}$. The dynamical age estimate is 6500 +/- 600 yr, while the best fit $n_e t$ value and derived $n_e$ gives 8200 +/- 1700 yr; the weighted mean of the age estimates is 7600 +/- 600 yr. We estimate an X-ray luminosity (0.25-4.5 keV) of (1.2 +/- 0.2) times $10^{37}$ ergs s$^{-1}$ (absorbed), and (1.7 +/- 0.3) times $10^{37}$ ergs s$^{-1}$ (unabsorbed), in good agreement with the recent XMM-Newton determination. No significant excess hard emission was detected; the luminosity $\\le 1.2\\times 10^{35}$ ergs s$^{-1}$ (2-8 keV) for any hard point source.

Terrance J. Gaetz; William P. Blair; John P. Hughes; P. Frank Winkler; Knox S. Long; Thomas G. Pannuti; Benjamin Williams; Richard J. Edgar; Parviz Ghavamian; Paul P. Plucinsky; Manami Sasaki; Robert P. Kirshner; Miguel Avillez; Dieter Breitschwerdt

2007-06-18T23:59:59.000Z

351

In situ x-ray diffraction studies of a new LiMg{sub 0.125}Ni{sub 0.75}O{sub 2} cathode material  

DOE Green Energy (OSTI)

A Synchrotron x-ray source was used for In Situ x-ray diffraction studies during charge on a new LiMg{sub 0.125}Ti{sub 0.125}Ni{sub 0.75} cathode material synthesized by FMC Corp. It had been demonstrated by Gao that this new material has superior thermal stability than LiNiO{sub 2} and LiCo{sub 0.2}Ni{sub 0.8}O{sub 2} at over-charged state. In this current paper, studies on the relationship between the structural changes and thermal stability at over-charged state for these materials are presented. For the first time, the thermal stability of these materials are related to their structural changes during charge, especially to the formation and lattice constant change of a hexagonal phase (H3). The spectral evidence support the hypothesis that the improvement of thermal stability is obtained by suppressing the formation of H3 phase and reducing the shrinkage of its lattice constant c when charged above 4.3 V.

Yang, X.Q.; Sun, X.; McBreen, J. [Brookhaven National Lab., Upton, NY (US); Gao, Y.; Yakovleva, M.V. [FMC Corp., Princeton, NJ (US); Xing, X.K.; Daroux, M.L. [Gould Electronics Inc., Eastlake, OH (US); Mukerjee, S. [Northeastern Univ., Boston, MA (US). Dept. of Chemistry

1999-07-01T23:59:59.000Z

352

Charge-coupled-device/fiberoptic taper array X-ray detector for protein crystallography  

SciTech Connect

A large area, charge-couple-device (CCD) based fiberoptic taper array detector (APS-1) has been installed at the insertion-device beamline of the Structural Biology Center at the ANL Advanced Photon Source. The detector is used in protein crystallography diffraction experiments, where the objective is to measure the position and intensity of X-ray Bragg peaks in diffraction images. Large imaging area, very high spatial resolution, high X-ray sensitivity, good detective quantum efficiency, low noise, wide dynamic range, excellent stability and short readout time are all fundamental requirements in this application. The APS-1 detector converts the two-dimensional X-ray patterns to a visible light images by a thin layer of X-ray sensitive phosphor. The phosphor coating is directly deposited on the large ends of nine fiberoptic tapers arranged in a 3x3 array. Nine, thermoelectrically cooled 1024 x 1024 pixel CCD`s image the patterns, demagnified by the tapers. After geometrical and uniformity corrections, the nine areas give a continuous image of the detector face with virtually no gaps between the individual tapers. The 18 parallel analog signal-processing channels and analog-to-digital converters assure short readout time and low readout noise.

Naday, I.; Ross, S.; Westbrook, E.M.; Zentai, G.

1997-03-01T23:59:59.000Z

353

Ultra-short wavelength x-ray system  

DOE Patents (OSTI)

A method and apparatus to generate a beam of coherent light including x-rays or XUV by colliding a high-intensity laser pulse with an electron beam that is accelerated by a synchronized laser pulse. Applications include x-ray and EUV lithography, protein structural analysis, plasma diagnostics, x-ray diffraction, crack analysis, non-destructive testing, surface science and ultrafast science.

Umstadter, Donald (Ann Arbor, MI); He, Fei (Ann Arbor, MI); Lau, Yue-Ying (Potomac, MD)

2008-01-22T23:59:59.000Z

354

X-Ray diffraction and vibrational spectroscopic study of 2-chloro-N-{l_brace}4-[3-(2,5-dimethylphenyl)-3-methylcyclobutyl] -thiazol-2-yl{r_brace}-acetamide  

SciTech Connect

The title compound C{sub 18}H{sub 21}ClN{sub 2}SO crystallizes with Z = 4 in space group P2{sub 1}/c. The structure of the title compound was characterized by {sup 1}H-NMR, {sup 13}C-NMR, IR and single crystal diffraction. There are an intermolecular N-H-O hydrogen bond and a C-H-{pi} interactions in crystal packing. In addition to the molecular geometry and packing obtained from X-ray experiment, the molecular geometry and vibrational frequencies of the title compound in ground state have been calculated using density functional theory method DFT (B3LYP) with 6-31G (d, p) basis set. Calculated frequencies, bond lengths, angles and dihedral angles are in good agreement with the corresponding experimental data.

Caliskan, Nezihe, E-mail: nezihec@omu.edu.tr; Guentepe, Feyizan [Ondokuz Mayis University, Department of Physics, Faculty of Arts and Sciences (Turkey); Yueksektepe, Cigdem [Cankiri Karatekin University, Department of Physics, Faculty of Science (Turkey); Cukurovali, Alaaddin [Firat University, Department of Chemistry, Faculty of Science (Turkey); Bueyuekguengoer, Orhan [Ondokuz Mayis University, Department of Physics, Faculty of Arts and Sciences (Turkey)

2010-12-15T23:59:59.000Z

355

Direct evidence of a zigzag spin-chain structure in the honeycomb lattice: A neutron and x-ray diffraction investigation of single-crystal Na2IrO3  

Science Conference Proceedings (OSTI)

We have combined single crystal neutron and x-ray diffractions to investigate the magnetic and crystal structures of the honeycomb lattice $\\rm Na_2IrO_3$. The system orders magnetically below $18.1(2)$~K with Ir$^{4+}$ ions forming zigzag spin chains within the layered honeycomb network with ordered moment of $\\rm 0.22(1)~\\mu_B$/Ir site. Such a configuration sharply contrasts the N{\\'{e}}el or stripe states proposed in the Kitaev-Heisenberg model. The structure refinement reveals that the Ir atoms form nearly ideal 2D honeycomb lattice while the $\\rm IrO_6$ octahedra experience a trigonal distortion that is critical to the ground state. The results of this study provide much-needed experimental insights into the magnetic and crystal structure crucial to the understanding of the exotic magnetic order and possible topological characteristics in the 5$d$-electron based honeycomb lattice.

Ye, Feng [ORNL; Chi, Songxue [ORNL; Cao, Huibo [ORNL; Chakoumakos, Bryan C [ORNL; Fernandez-Baca, Jaime A [ORNL; Custelcean, Radu [ORNL; Qi, Tongfei [University of Kentucky; Korneta, O. B. [University of Kentucky, Lexington; Cao, Gang [University of Kentucky

2012-01-01T23:59:59.000Z

356

X-ray grid-detector apparatus  

DOE Patents (OSTI)

A hybrid grid-detector apparatus for x-ray systems wherein a microchannel plate structure has an air-interspaced grid portion and a phosphor/optical fluid-filled grid portion. The grids are defined by multiple adjacent channels separated by lead-glass septa. X-rays entering the air-interspaced grid portion at an angle of impingement upon the septa are attenuated, while non-impinging x-rays pass through to the phosphor/fluid filled portion. X-ray energy is converted to luminescent energy in the phosphor/fluid filled portion and the resultant beams of light are directed out of the phosphor/optical fluid filled portion to an imaging device.

Boone, John M. (Folsom, CA); Lane, Stephen M. (Oakland, CA)

1998-01-27T23:59:59.000Z

357

Synchrotron X-ray scattering techniques for microelectronics-related materials studies  

Science Conference Proceedings (OSTI)

X-ray diffraction techniques using synchrotron radiation play a vital role in the understanding of structural behavior for a wide range of materials important in microelectronics. The extremely high flux of X-rays produced by synchrotron storage rings ...

J. L. Jordan-Sweet

2000-07-01T23:59:59.000Z

358

Time-resolved x-ray imaging of high-power laser-irradiated under-dense silica aerogels and agar foams  

SciTech Connect

This paper presents the results of experiments in which a high-power laser was used to irradiate low density (4 - 9 mg/cm{sup 3}) silica aerogel and agar foam targets. The laser-solid interaction and energy transport through the material were monitored with time-resolved imaging diagnostics, and the data show the production and propagation of an x-ray emission front in the plasma. The emission-front trajectory data are found to be in significant disagreement with detailed simulations, which predict a much more rapid heating of the cold material, and the data suggest that this discrepancy is not explainable by target inhomogeneities. Evidence suggests that energy transport into the cold material may be dominated by thermal conduction; however, no completely satisfactory explanation for the discrepancies is identified, and further experimental and theoretical research is necessary in order to resolve this important problem in laser-plasma interaction physics.

Koch, J.A.; Estabrook, K.G.; Bauer, J.D. [and others

1995-08-01T23:59:59.000Z

359

Direct detection of x-rays for protein crystallography  

DOE Patents (OSTI)

An apparatus and method for directly determining the crystalline structure of a protein crystal. The crystal is irradiated by a finely collimated x-ray beam. The interaction o f the x-ray beam with the crystal produces scattered x-rays. These scattered x-rays are detected by means of a large area, thick CCD which is capable of measuring a significant number of scattered x-rays which impact its surface. The CCD is capable of detecting the position of impact of the scattered x-ray on the surface of the CCD and the quantity of scattered x-rays which impact the same cell or pixel. This data is then processed in real-time and the processed data is outputted to produce an image of the structure of the crystal. If this crystal is a protein the molecular structure of the protein can be determined from the data received.

Atac, Muzaffer; McKay, Timothy

1997-12-01T23:59:59.000Z

360

Fluctuation X-Ray Scattering  

SciTech Connect

The work supported by the grant was aimed at developing novel methods of finding the structures of biomolecules using x-rays from novel sources such as the x-ray free electron laser and modern synchrotrons

Saldin, PI: D. K.; Co-I's: J. C. H. Spence and P. Fromme

2013-01-25T23:59:59.000Z

Note: This page contains sample records for the topic "x-ray diffraction imaging" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


361

APS 7-BM Beamline: X-Ray Resources  

NLE Websites -- All DOE Office Websites (Extended Search)

Useful Websites Useful Websites X-Ray Interactions with Matter from CRXO at LBNL. Intuitive interface for x-ray transmission and reflectivity for a wide range of materials. X-Ray Data Booklet from LBNL. Slightly outdated in places, but many useful tables of edge energies, fluorescence lines, and crystal lattice spacings. NIST XCOM Database. Powerful database of photoelectric absorption, elastic scattering, and Compton scattering cross-sections for a wide range of materials. X-Ray Server. Maintained by Sergey Stepanov at GMCA at the APS, this website has several powerful calculators for simulating x-ray reflection and diffraction. Software X-Ray Oriented Programs (XOP). This program, written by scientists at the ESRF and APS, is widely used in the synchrotron research community.

362

Soft x-ray microscopy - a powerful analytical tool to image magnetism down to fundamental length and times scales  

E-Print Network (OSTI)

image magnetism down to fundamental length and time scalesmicroscopies have to tackle fundamental magnetic length andregard to addressing fundamental magnetic length and time

Fischer, Peter

2008-01-01T23:59:59.000Z

363

X-ray Security Screening  

Science Conference Proceedings (OSTI)

National and International Standards for X-ray Security Screening Applications. Summary: The primary objective of this ...

2013-03-13T23:59:59.000Z

364

Hydrogen in polar intermetallics: Syntheses and structures of the ternary Ca5Bi3D0.93, Yb5Bi3Hx, and Sm5Bi3H~1 by powder neutron or single crystal X-ray diffraction  

DOE Green Energy (OSTI)

The syntheses of the title compounds are described in detail. Structural characterizations from refinements of single crystal X-ray diffraction data for Yb{sub 5}Bi{sub 3}H{sub x} and Sm{sub 5}Bi{sub 3}H{sub 1} and of powder neutron diffraction data for Ca{sub 5}Bi{sub 3}D{sub 0.93(3)} are reported. These confirm that all three crystallize with the heavy atom structure type of {beta}-Yb{sub 5}Sb{sub 3}, and the third gives the first proof that the deuterium lies in the center of nominal calcium tetrahedra, isostructural with the Ca{sub 5}Sb{sub 3}F-type structure. These Ca and Yb phases are particularly stable with respect to dissociation to Mn{sub 5}Si{sub 3}-type product plus H{sub 2}. Some contradictions in the literature regarding Yb{sub 5}Sb{sub 3} and Yb{sub 5}Sb{sub 3}H{sub x} phases are considered in terms of adventitious hydrogen impurities that are generated during reactions in fused silica containers at elevated temperatures.

Leon-Escamilla, E. Alejandro; Dervenagas, Panagiotis; Stasis, Constantine; Corbett, John D.

2010-01-01T23:59:59.000Z

365

Tunable X-ray source  

DOE Patents (OSTI)

A method for the production of X-ray bunches tunable in both time and energy level by generating multiple photon, X-ray, beams through the use of Thomson scattering. The method of the present invention simultaneously produces two X-ray pulses that are tunable in energy and/or time.

Boyce, James R. (Williamsburg, VA)

2011-02-08T23:59:59.000Z

366

Workshops on Science Enabled by a Coherent, CW, Synchrotron X-ray Source, June 2011  

Science Conference Proceedings (OSTI)

In June of 2011 we held six two-day workshops called "XDL-2011: Science at the Hard X-ray Diffraction Limit". The six workshops covered (1) Diffraction-based imaging techniques, (2) Biomolecular structure from non-crystalline materials, (3) Ultra-fast science, (4) High-pressure science, (5) Materials research with nano-beams and (6) X-ray photon correlation spectroscopy (XPCS), In each workshop, invited speaker from around the world presented examples of novel experiments that require a CW, diffraction-limited source. During the workshop, each invited speaker provided a one-page description of the experiment and an illustrative graphic. The experiments identified by the workshops demonstrate the broad and deep scientific case for a CW coherent synchrotron x-ray source. The next step is to perform detailed simulations of the best of these ideas to test them quantitatively and to guide detailed x-ray beam-line designs. These designs are the first step toward developing detailed facility designs and cost estimates.

Brock, Joel

2012-01-03T23:59:59.000Z

367

Automated Registration of Volumes of Interest for a Combined X-Ray Tomosynthesis and Ultrasound Breast Imaging System  

Science Conference Proceedings (OSTI)

An intuitive display method was developed to enable a user to select and visualize corresponding volumes of interest in combined digital breast tomosynthesis (DBT) and automated breast ultrasound images. Details of this method are described including ...

Mitchell M. Goodsitt; Heang-Ping Chan; Lubomir Hadjiiski; Gerald L. Lecarpentier; Paul L. Carson

2008-07-01T23:59:59.000Z

368

Sharper Focusing of Hard X-rays  

NLE Websites -- All DOE Office Websites (Extended Search)

Sharper Focusing of Hard X-rays FROM: Physics News Update Number 773 #1, April 12, 2006, by Phil Schewe and Ben Stein Note: This text has been slightly modified from the original. Sharper focusing of hard x-rays has been achieved with a device developed at Argonne National Lab. Because of their high energy, x-rays are hard to focus: they can be reflected from a surface but only at a glancing angle (less than a tenth of a degree); they can be refracted but the index of refraction is very close to 1, so that making efficient lenses becomes a problem; and they can be diffracted, but the relatively thick, variable pitch grating required for focusing is tricky to achieve. The Argonne device is of the diffraction type, and it consists of a stack of alternating layers of metal and silicon, made by depositing progressively thicker layers. When the x-rays fall on such a structure, nearly edge-on, what they see is a grating (called a linear zone plate) consisting of a sort of bar-code pattern.

369

Purification, crystallization and preliminary X-ray diffraction analysis of the carbohydrate-binding region of the Streptococcus gordonii adhesin GspB  

Science Conference Proceedings (OSTI)

The carbohydrate-binding region of the bacterial adhesin GspB from Streptococcus gordonii strain M99 (GspB{sub BR}) was expressed in Escherichia coli and purified using affinity and size-exclusion chromatography. Separate sparse-matrix screening of GspB{sub BR} buffered in either 20 mM Tris pH 7.4 or 20 mM HEPES pH 7.5 resulted in different crystallographic behavior such that different precipitants, salts and additives supported crystallization of GspB{sub BR} in each buffer. While both sets of conditions supported crystal growth in space group P2{sub 1}2{sub 1}2{sub 1}, the crystals had distinct unit-cell parameters of a = 33.3, b = 86.7, c = 117.9 {angstrom} for crystal form 1 and a = 34.6, b = 98.3, c = 99.0 {angstrom} for crystal form 2. Additive screening improved the crystals grown in both conditions such that diffraction extended to beyond 2 {angstrom} resolution. A complete data set has been collected to 1.3 {angstrom} resolution with an overall R{sub merge} value of 0.04 and an R{sub merge} value of 0.33 in the highest resolution shell.

Pyburn, Tasia M.; Yankovskaya, Victoria; Bensing, Barbara A.; Cecchini, Gary; Sullam, Paul M.; Iverson, T.M. (VA); (Vanderbilt); (UCSF)

2012-07-11T23:59:59.000Z

370

Scanning x-ray microscope  

Science Conference Proceedings (OSTI)

A scanning x-ray microscope is described including: an x-ray source capable of emitting a beam of x-rays; a collimator positioned to receive the beam of x-rays and to collimate this beam, a focusing cone means to focus the beam of x-rays, directed by the collimator, onto a focal plane, a specimen mount for supporting a specimen in the focal plane to receive the focused beam of x-rays, and x-ray beam scanning means to relatively move the specimen and the focusing cone means and collimator to scan the focused x-ray beam across the specimen. A detector is disposed adjacent the specimen to detect flourescent photons emitted by the specimen upon exposure to the focused beam of x-rays to provide an electrical output representative of this detection. Means are included for displaying and/or recording the information provided by the output from the detector, as are means for providing information to the recording and/or display means representative of the scan rate and position of the focused x-ray beam relative to the specimen whereby the recording and/or display means can correlate the information received to record and/or display quantitive and distributive information as to the quantity and distribution of elements detected in the specimen. Preferably there is provided an x-ray beam modulation means upstream, relative to the direction of emission of the xray beam, of the focusing cone means.

Wang, C.

1982-02-23T23:59:59.000Z

371

X-ray lithography source  

SciTech Connect

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.

Piestrup, Melvin A. (Woodside, CA); Boyers, David G. (Mountain View, CA); Pincus, Cary (Sunnyvale, CA)

1991-01-01T23:59:59.000Z

372

X-ray lithography source  

DOE Patents (OSTI)

A high-intensity, inexpensive X-ray source for X-ray lithography for the production of integrated circuits is disclosed. 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 eliminating 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 excellent moderate-priced X-ray source for lithography. 26 figures.

Piestrup, M.A.; Boyers, D.G.; Pincus, C.

1991-12-31T23:59:59.000Z

373

Fabrication process for a gradient index x-ray lens  

DOE Patents (OSTI)

A process for fabricating high efficiency x-ray lenses that operate in the 0.5-4.0 keV region suitable for use in biological imaging, surface science, and x-ray lithography of integrated circuits. The gradient index x-ray optics fabrication process broadly involves co-sputtering multi-layers of film on a wire, followed by slicing and mounting on block, and then ion beam thinning to a thickness determined by periodic testing for efficiency. The process enables the fabrication of transmissive gradient index x-ray optics for the 0.5-4.0 keV energy range. This process allows the fabrication of optical elements for the next generation of imaging and x-ray lithography instruments m the soft x-ray region.

Bionta, Richard M. (Livermore, CA); Makowiecki, Daniel M. (Livermore, CA); Skulina, Kenneth M. (Livermore, CA)

1995-01-01T23:59:59.000Z

374

Fabrication process for a gradient index x-ray lens  

DOE Patents (OSTI)

A process is disclosed for fabricating high efficiency x-ray lenses that operate in the 0.5-4.0 keV region suitable for use in biological imaging, surface science, and x-ray lithography of integrated circuits. The gradient index x-ray optics fabrication process broadly involves co-sputtering multi-layers of film on a wire, followed by slicing and mounting on block, and then ion beam thinning to a thickness determined by periodic testing for efficiency. The process enables the fabrication of transmissive gradient index x-ray optics for the 0.5-4.0 keV energy range. This process allows the fabrication of optical elements for the next generation of imaging and x-ray lithography instruments in the soft x-ray region. 13 figures.

Bionta, R.M.; Makowiecki, D.M.; Skulina, K.M.

1995-01-17T23:59:59.000Z

375

Refractive Optics for Hard X-ray Transmission Microscopy  

Science Conference Proceedings (OSTI)

For hard x-ray transmission microscopy at photon energies higher than 15 keV we design refractive condenser and imaging elements to be used with synchrotron light sources as well as with x-ray tube sources. The condenser lenses are optimized for low x-ray attenuation--resulting in apertures greater than 1 mm--and homogeneous intensity distribution on the detector plane, whereas the imaging enables high-resolution (condenser and imaging lenses are being developed. The imaging lenses (compound refractive lenses, CRLs) are made of SU-8 negative resist by deep x-ray lithography. SU-8 shows high radiation stability. The fabrication technique enables high-quality lens structures regarding surface roughness and arrangement precision with arbitrary 2D geometry. To provide point foci, crossed pairs of lenses are used. Condenser lenses have been made utilizing deep x-ray lithographic patterning of thick SU-8 layers, too, whereas in this case, the aperture is limited due to process restrictions. Thus, in terms of large apertures, condenser lenses made of structured and rolled polyimide film are more attractive. Both condenser types, x-ray mosaic lenses and rolled x-ray prism lenses (RXPLs), are considered to be implemented into a microscope setup. The x-ray optical elements mentioned above are characterized with synchrotron radiation and x-ray laboratory sources, respectively.

Simon, M.; Last, A.; Mohr, J.; Nazmov, V.; Reznikova, E. [Institute for Microstructure Technology, Karlsruhe Institute of Technology Kaiserstrasse 12, 76131 Karlsruhe (Germany); Ahrens, G.; Voigt, A. [Microresist Technology, Koepenikerstrasse 325, 12555 Berlin (Germany)

2011-09-09T23:59:59.000Z

376

Design and development of a 3D X-ray microscope  

E-Print Network (OSTI)

The rapid development of needle-free injection systems demands better and faster imaging systems, capable of imaging the transient and steady state response of an injection into real tissue. X-ray radiography, x-ray ...

Brayanov, Jordan, 1981-

2006-01-01T23:59:59.000Z

377

Stokes imaging of AM Her systems using 3D inhomogeneous models-II. Modelling X-ray and optical data of CP Tucanae  

E-Print Network (OSTI)

The viewing geometry of the polar CP Tuc that better explains its optical and X-ray light curves is controversial. Previous modelling of white-light polarimetric data considered the partial self-eclipse of an extended inhomogeneous emitting region. Alternatively, phase-dependent absorption has been used to reproduce the X-ray data. This paper presents new optical polarimetric data of CP Tuc and a model that consistently explains its optical and X-ray data. The model was based on an extension of the CYCLOPS code that added X-ray bremsstrahlung emission and pre-shock region absorption to the original version, which only accounted for cyclotron emission. The new code creates the possibility of simultaneous optical and X-ray fitting. We show that self-eclipse and absorption data have distinct signatures on the X-ray spectra. Although we were able to reasonably fit the CP Tuc optical data to cases of absorption and self-eclipse, we were only able to reproduce the X-ray orbital modulation after considering the abso...

Silva, K M G; Costa, J E R; de Souza, C A; Cieslinski, D; Hickel, G R

2013-01-01T23:59:59.000Z

378

High Flux Water Window X-rays Driven by Ultrashort 1.8mm Laser ...  

Science Conference Proceedings (OSTI)

About this Abstract. Meeting, Materials Science & Technology 2013. Symposium, Optical and X-ray Imaging Techniques for Material Characterization.

379

In Situ X-ray Nanocharacterization of Defects in Solar Cells  

Science Conference Proceedings (OSTI)

About this Abstract. Meeting, Materials Science & Technology 2013. Symposium, Optical and X-ray Imaging Techniques for Material Characterization.

380

Enhanced x-ray imaging for a thin film cochlear implant with metal artefacts using phase retrieval tomography  

SciTech Connect

Phase retrieval tomography has been successfully used to enhance imaging in systems that exhibit poor absorption contrast. However, when highly absorbing regions are present in a sample, so-called metal artefacts can appear in the tomographic reconstruction. We demonstrate that straightforward approaches for metal artefact reconstruction, developed in absorption contrast tomography, can be applied when using phase retrieval. Using a prototype thin film cochlear implant that has high and low absorption components made from iridium (or platinum) and plastic, respectively, we show that segmentation of the various components is possible and hence measurement of the electrode geometry and relative location to other regions of interest can be achieved.

Arhatari, B. D. [Department of Physics, La Trobe University, Victoria 3086 (Australia); ARC Centre of Excellence for Coherent X-ray Science, Melbourne (Australia); Harris, A. R.; Paolini, A. G. [School of Psychological Science, La Trobe University, Victoria 3086 (Australia); ARC Centre of Excellence for Electromaterials Science, Melbourne (Australia); Peele, A. G. [Department of Physics, La Trobe University, Victoria 3086 (Australia); ARC Centre of Excellence for Coherent X-ray Science, Melbourne (Australia); Australian Synchrotron, Victoria 3168 (Australia)

2012-06-01T23:59:59.000Z

Note: This page contains sample records for the topic "x-ray diffraction imaging" from the National Library of EnergyBeta (NLEBeta).
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381

Epitaxial BaTiO{sub 3}(100) films on Pt(100): A low-energy electron diffraction, scanning tunneling microscopy, and x-ray photoelectron spectroscopy study  

Science Conference Proceedings (OSTI)

The growth of epitaxial ultrathin BaTiO{sub 3} films on a Pt(100) substrate has been studied by scanning tunneling microscopy (STM), low-energy electron diffraction (LEED), and x-ray photoelectron spectroscopy (XPS). The films have been prepared by radio-frequency-assisted magnetron sputter deposition at room temperature and develop a long-range order upon annealing at 900 K in O{sub 2}. By adjusting the Ar and O{sub 2} partial pressures of the sputter gas, the stoichiometry was tuned to match that of a BaTiO{sub 3}(100) single crystal as determined by XPS. STM reveals the growth of continuous BaTiO{sub 3} films with unit cell high islands on top. With LEED already for monolayer thicknesses, the formation of a BaTiO{sub 3}(100)-(1 x 1) structure has been observed. Films of 2-3 unit cell thickness show a brilliant (1 x 1) LEED pattern for which an extended set of LEED I-V data has been acquired. At temperatures above 1050 K the BaTiO{sub 3} thin film starts to decay by formation of vacancy islands. In addition (4 x 4) and (3 x 3) surface reconstructions develop upon prolonged heating.

Foerster, Stefan; Huth, Michael; Schindler, Karl-Michael; Widdra, Wolf [Institute of Physics, Martin-Luther-Universitaet Halle-Wittenberg, Halle (Germany)

2011-09-14T23:59:59.000Z

382

X-ray Science Division: Groups  

NLE Websites -- All DOE Office Websites (Extended Search)

Division: Groups Division: Groups Atomic, Molecular and Optical Physics (AMO) Primary Contact: Stephen Southworth Work focuses on understanding how strong optical and x-ray fields interact with matter, with an emphasis on photonic control of electronic, atomic and molecular motion. Chemical and Materials Science (CMS) Primary Contact: Randy Winans Research Disciplines: Chemistry, Materials Science Detectors (DET) Primary Contact: Antonino Miceli GMCA Structural Biology Facility (MX) Primary Contact: Robert Fischetti Research Disciplines: Biology, Life Sciences Imaging (IMG) Primary Contact: Francesco DeCarlo Research Disciplines: Materials Science, Biology, Physics, Life Sciences Inelastic X-ray & Nuclear Resonant Scattering (IXN) Primary Contact: Thomas Gog Research Disciplines: Condensed Matter Physics, Geophysics, Materials

383

Radiographic X-Ray Pulse Jitter  

Science Conference Proceedings (OSTI)

The Dual Beam Radiographic Facility consists of two identical radiographic sources. Major components of the machines are: Marx generator, water-filled pulse-forming line (PFL), water-filled coaxial transmission line, three-cell inductive voltage adder, and rod-pinch diode. The diode pulse has the following electrical specifications: 2.25-MV, 60-kA, 60-ns. Each source has the following x-ray parameters: 1-mm-diameter spot size, 4-rad at 1 m, 50-ns full width half max. The x-ray pulse is measured with PIN diode detectors. The sources were developed to produce high resolution images on single-shot, high-value experiments. For this application it is desirable to maintain a high level of reproducibility in source output. X-ray pulse jitter is a key metric for analysis of reproducibility. We will give measurements of x-ray jitter for each machine. It is expected that x-ray pulse jitter is predominantly due to PFL switch jitter, and therefore a correlation of the two will be discussed.

Mitton, C. V., Good, D. E., Henderson, D. J., Hogge, K. W.

2011-01-15T23:59:59.000Z

384

Frontiers in X-Ray Science  

Science Conference Proceedings (OSTI)

The year 2010 marked the fiftieth anniversary of the optical laser and the first anniversary of the world's first hard x-ray free-electron laser, the Linac Coherent Light Source (LCLS) at SLAC. This exciting, new accelerator-based source of x-rays provides peak brilliances roughly a billion times greater than currently available from synchrotron sources such as the Advanced Photon Source at Argonne, and thus explores a qualitatively different parameter space. This talk will describe the first experiments at the LCLS aimed at understanding the nature of high intensity x-ray interactions, related applications in ultrafast imaging on the atomic scale and sketch nascent plans for the extension of both linac and storage-ring based photon sources.

Linda Young

2011-02-23T23:59:59.000Z

385

Miniature x-ray source  

DOE Patents (OSTI)

A miniature x-ray source capable of producing broad spectrum x-ray emission over a wide range of x-ray energies. The miniature x-ray source comprises a compact vacuum tube assembly containing a cathode, an anode, a high voltage feedthru for delivering high voltage to the anode, a getter for maintaining high vacuum, a connection for an initial vacuum pump down and crimp-off, and a high voltage connection for attaching a compact high voltage cable to the high voltage feedthru. At least a portion of the vacuum tube wall is highly x-ray transparent and made, for example, from boron nitride. The compact size and potential for remote operation allows the x-ray source, for example, to be placed adjacent to a material sample undergoing analysis or in proximity to the region to be treated for medical applications.

Trebes, James E. (Livermore, CA); Stone, Gary F. (Livermore, CA); Bell, Perry M. (Tracy, CA); Robinson, Ronald B. (Modesto, CA); Chornenky, Victor I. (Minnetonka, MN)

2002-01-01T23:59:59.000Z

386

Direct Deposition of Microcolumnar Scintillator on CMOS SSPM Array: Toward a Photon Counting Detector for X-Ray/Gamma Ray Imaging  

SciTech Connect

We are developing a modular, low-cost, photon-counting detector based on a scintillator coupled to a solid-state photodetector. A working prototype was successfully developed by depositing CsI:Tl directly onto a CMOS SSPM array designed by RMD and custom-fabricated by a commercial foundry. The device comprised a 6x6 array of 1.5x1.5 mm{sup 2} macro-pixels, each containing a 36x36 array of resistively coupled micro-pixels, that was subjected to vapor deposition of columnar CsI:Tl. Direct deposition eliminates the gap between the scintillator and SSPM and creates a better optical bond than does index-matching grease. This paper compares the performance of SSPMs with directly deposited CsI:Tl, in terms of signal-to-noise ratio and light spread, against devices using monolithic single crystals or pixelated single crystals coupled to the SSPM. Due to the reduction in light scattering and optical losses in the interface, the directly deposited CsI:Tl demonstrated significantly better position sensitivity, with at least a factor of 2 increase in SNR compared to a single crystal. These data indicate that a photodetector with substantially smaller macro-pixel dimensions than used here could be used to implement a low-energy X-ray/gamma-ray imaging and spectroscopy detector, particularly for applications where high resolution is of prime importance.

Prekas, G.; Breen, M.; Sabet, H.; Bhandari, H.; Derderian, G.; Robertson, F. Jr; Stapels, C. J.; Christian, J.; Cool, S.; Nagarkar, V. V. [Radiation Monitoring Devices, Inc., 44 Hunt Street, Watertown, Massachusetts 02472 (United States)

2011-12-13T23:59:59.000Z

387

Synchrotron X-ray Measurements  

Science Conference Proceedings (OSTI)

... fine structure (EXAFS) spectroscopy; (3) variable kinetic energy X-ray ... advanced materials is critical to the development and optimization of products ...

2012-10-04T23:59:59.000Z

388

X-ray Absorption Spectroscopy  

SciTech Connect

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.

Yano, Junko; Yachandra, Vittal K.

2009-07-09T23:59:59.000Z

389

X-Ray and Neutron Diffraction  

Science Conference Proceedings (OSTI)

Oct 27, 2009 ... Use of the Advanced Photon Source at Argonne National Laboratory was supported by the U. S. Department of Energy, Office of Science, Office ...

390

High resolution x-ray microscope  

Science Conference Proceedings (OSTI)

The authors present x-ray images of grid meshes and biological material obtained using a microspot x-ray tube with a multilayer optic and a 92-element parabolic compound refractive lens (CRL) made of a plastic containing only hydrogen and carbon. Images obtained using this apparatus are compared with those using an area source with a spherical lens and a spherical lens with multilayer condenser. The authors found the best image quality using the multilayer condenser with a parabolic lens, compared to images with a spherical lens and without the multilayer optics. The resolution was measured using a 155-element parabolic CRL and a multilayer condenser with the microspot tube. The experiment demonstrates about 1.1 {mu}m resolution.

Gary, C. K.; Park, H.; Lombardo, L. W.; Piestrup, M. A.; Cremer, J. T.; Pantell, R. H.; Dudchik, Y. I. [Adelphi Technology, Inc. 981-B Industrial Road, San Carlos, California 94070 (United States); Department of Electrical Engineering, Stanford University, Stanford, California 94305 (United States); Institute of Applied Physics Problems, Kurchatova 7, Minsk 220064 (Belarus)

2007-04-30T23:59:59.000Z

391

Post-spinel transformations and equation of state in ZnGa[subscript 2]O[subscript 4]: Determination at high pressure by in situ x-ray diffraction  

Science Conference Proceedings (OSTI)

Room-temperature angle-dispersive x-ray diffraction measurements on spinel ZnGa{sub 2}O{sub 4} up to 56 GPa show evidence of two structural phase transformations. At 31.2 GPa, ZnGa{sub 2}O{sub 4} undergoes a transition from the cubic spinel structure to a tetragonal spinel structure similar to that of ZnMn{sub 2}O{sub 4}. At 55 GPa, a second transition to the orthorhombic marokite structure (CaMn{sub 2}O{sub 4}-type) takes place. The equation of state of cubic spinel ZnGa{sub 2}O{sub 4} is determined: V{sub 0} = 580.1(9) {angstrom}{sup 3}, B{sub 0} = 233(8) GPa, B'{sub 0} = 8.3(4), and B''{sub 0} = -0.1145 GPa{sup -1} (implied value); showing that ZnGa{sub 2}O{sub 4} is one of the less compressible spinels studied to date. For the tetragonal structure an equation of state is also determined: V{sub 0} = 287.8(9) {angstrom}{sup 3}, B{sub 0} = 257(11) GPa, B'{sub 0} = 7.5(6), and B''{sub 0} = -0.0764 GPa{sup -1} (implied value). The reported structural sequence coincides with that found in NiMn{sub 2}O{sub 4} and MgMn{sub 2}O{sub 4}.

Errandonea, D.; Kumar, Ravhi S.; Manjón, F.J.; Ursaki, V.V.; Rusu, E.V.; (UNLV); (Acad.Sci.-Moldova); (Valencia)

2009-01-15T23:59:59.000Z

392

Soft x-ray laser microscope  

Science Conference Proceedings (OSTI)

The program consisted of two phases (Phase I and Phase II). The goal of the Phase I (first year program) was to design and construct the Soft X-ray Laser Contact Microscope. Such microscope was constructed and adapted to PPL's 18.2nm soft X-ray Laser (SXL), which in turn was modified and prepared for microscopy experiments. Investigation of the photoresist response to 18.2nm laser radiation and transmissivity of 0.1m thick silicion-nitride (Si[sub 3]N[sub 4]) windows were important initial works. The goal of the first year of Phase II was to construct X-ray contact microscope in combination with existing optical phase microscope, already used by biologists. In the second year of Phase II study of dehydrated Horeseshoe Crab and Hela cancer cells were performed with COXRALM. Also during Phase II, the Imaging X-Ray Laser Microscope (IXRALM) was designed and constructed. This paper describes the development of each of the microscopes and their application for research.

Suckewer, P.I.

1990-10-01T23:59:59.000Z

393

Direct three-dimensional coherently scattered x-ray microtomography  

Science Conference Proceedings (OSTI)

Purpose: It has been shown that coherently scattered x rays can be used to discriminate and identify specific components in a mixture of low atomic weight materials. The authors demonstrated a new method of doing coherently scattered x-ray tomography with a thin sheet of x ray. Methods: A collimated x-ray fan-beam, a parallel polycapillary collimator, and a phantom consisting of several biocompatible materials of low attenuation-based contrast were used to investigate the feasibility of the method. Because of the particular experimental setup, only the phantom translation perpendicular to the x-ray beam is needed and, thus, there is no need of Radon-type tomographic reconstruction, except for the correction of the attenuation to the primary and scattered x rays, which was performed by using a conventional attenuation-based tomographic image data set. The coherent scatter image contrast changes with momentum transfer among component materials in the specimen were investigated with multiple x-ray sources with narrow bandwidth spectra generated with anode and filter combinations of Cu/Ni (8 keV), Mo/Zr (18 keV), and Ag/Pd (22 keV) and at multiple scatter angles by orienting the detector and polycapillary collimator at different angles to the illuminating x ray. Results: The contrast among different materials changes with the x-ray source energy and the angle at which the image was measured. The coherent scatter profiles obtained from the coherent scatter images are consistent with the published results. Conclusions: This method can be used to directly generate the three-dimensional coherent scatter images of small animal, biopsies, or other small objects with low atomic weight biological or similar synthetic materials with low attenuation contrast. With equipment optimized, submillimeter spatial resolution may be achieved.

Cui Congwu; Jorgensen, Steven M.; Eaker, Diane R.; Ritman, Erik L. [Department of Medical Physics, CancerCare Manitoba, 675 McDermot Avenue, Winnipeg, Manitoba R3E 0V9 (Canada); Department of Physiology and Biomedical Engineering, Mayo Clinic, 200 First Street Southwest, Alfred Building 2-409, Rochester, Minnesota 55905 (United States)

2010-12-15T23:59:59.000Z

394

Miniature x-ray source  

DOE Patents (OSTI)

A miniature x-ray source utilizing a hot filament cathode. The source has a millimeter scale size and is capable of producing broad spectrum x-ray emission over a wide range of x-ray energies. The miniature source consists of a compact vacuum tube assembly containing the hot filament cathode, an anode, a high voltage feedthru for delivering high voltage to the cathode, a getter for maintaining high vacuum, a connector for initial vacuum pump down and crimp-off, and a high voltage connection for attaching a compact high voltage cable to the high voltage feedthru. At least a portion of the vacuum tube wall is fabricated from highly x-ray transparent materials, such as sapphire, diamond, or boron nitride.

Trebes, James E. (Livermore, CA); Bell, Perry M. (Tracy, CA); Robinson, Ronald B. (Modesto, CA)

2000-01-01T23:59:59.000Z

395

High-energy x-ray production with pyroelectric crystals  

Science Conference Proceedings (OSTI)

The invention of pyroelectric x-ray generator technology has enabled researchers to develop ultraportable, low-power x-ray sources for use in imaging, materials analysis, and other applications. For many applications, the usefulness of an x-ray source is determined by its yield and endpoint energy. In x-ray fluorescence, for example, high-energy sources enable the excitation of the K-shell x-ray peaks for high-Z materials as well as the lower-energy L-shell peaks, allowing more positive sample identification. This report shows how a paired-crystal pyroelectric source can be used to approximately double the endpoint x-ray energy, in addition to doubling the x-ray yield, versus a single-crystal source. As an example of the advantage of a paired-crystal system, we present a spectrum showing the fluorescence of the K shell of thorium using a pyroelectric source, as well as a spectrum showing the fluorescence of the K shell of lead. Also shown is an x-ray spectrum with an endpoint energy of 215 keV.

Geuther, Jeffrey A.; Danon, Yaron [Department of Mechanical, Aerospace, and Nuclear Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180 (United States)

2005-05-15T23:59:59.000Z

396

Structural Characterization of Doped GaSb Single Crystals by X-ray Topography  

Science Conference Proceedings (OSTI)

We characterized GaSb single crystals containing different dopants (Al, Cd and Te), grown by the Czochralski method, by x-ray topography and high angular resolution x-ray diffraction. Lang topography revealed dislocations parallel and perpendicular to the crystal's surface. Double-crystal GaSb 333 x-ray topography shows dislocations and vertical stripes than can be associated with circular growth bands. We compared our high-angular resolution x-ray diffraction measurements (rocking curves) with the findings predicted by the dynamical theory of x-ray diffraction. These measurements show that our GaSb single crystals have a relative variation in the lattice parameter ({Delta}d/d) on the order of 10{sup -5}. This means that they can be used as electronic devices (detectors, for example) and as x-ray monochromators.

Honnicke, M.G.; Mazzaro, I.; Manica, J.; Benine, E.; M da Costa, E.; Dedavid, B. A.; Cusatis, C.; Huang, X. R.

2009-09-13T23:59:59.000Z

397

X-ray Transition Energies Search Form  

Science Conference Proceedings (OSTI)

[skip navigation] X-ray Transition Energies Database Main Page Search for X-ray transition energies by element(s), transition ...

398

Focal plane instrumentation for the Wide-Field X-ray Telescope  

E-Print Network (OSTI)

The three X-ray imaging focal planes of the Wide-Field X-ray Telescope (WFXT) Mission will each have a field of view up to 1 degree square, pixel pitch smaller than 1 arcsec, excellent X-ray detection efficiency and spectral ...

Bautz, Marshall W.

399

Chandra X-ray Observatory Detection of Extended X-ray Emission from the Planetary Nebula BD+303639  

E-Print Network (OSTI)

We report the detection of well resolved, extended X-ray emission from the young planetary nebula BD+303639 using the Advanced CCD Imaging Spectrometer (ACIS) aboard the Chandra X-ray Observatory. The X-ray emission from BD+303639 appears to lie within, but is concentrated to one side of, the interior of the shell of ionized gas seen in high-resolution optical and IR images. The relatively low X-ray temperature (Tx ~ 3x10^6 K) and asymmetric morphology of the X-ray emission suggests that conduction fronts are present and/or mixing of shock-heated and photoionized gas has occurred and, furthermore, hints at the presence of magnetic fields. The ACIS spectrum suggests that the X-ray emitting region is enriched in the products of helium burning. Our detection of extended X-ray emission from BD+303639 demonstrates the power and utility of Chandra imaging as applied to the study of planetary nebulae.

Kästner, J H; Vrtilek, S D; Dgani, R; Kastner, Joel H.; Soker, Noam; Vrtilek, Saeqa; Dgani, Ruth

2000-01-01T23:59:59.000Z

400

Chandra X-ray Observatory Detection of Extended X-ray Emission from the Planetary Nebula BD+303639  

E-Print Network (OSTI)

We report the detection of well resolved, extended X-ray emission from the young planetary nebula BD+303639 using the Advanced CCD Imaging Spectrometer (ACIS) aboard the Chandra X-ray Observatory. The X-ray emission from BD+303639 appears to lie within, but is concentrated to one side of, the interior of the shell of ionized gas seen in high-resolution optical and IR images. The relatively low X-ray temperature (Tx ~ 3x10^6 K) and asymmetric morphology of the X-ray emission suggests that conduction fronts are present and/or mixing of shock-heated and photoionized gas has occurred and, furthermore, hints at the presence of magnetic fields. The ACIS spectrum suggests that the X-ray emitting region is enriched in the products of helium burning. Our detection of extended X-ray emission from BD+303639 demonstrates the power and utility of Chandra imaging as applied to the study of planetary nebulae.

Joel H. Kastner; Noam Soker; Saeqa Vrtilek; Ruth Dgani

2000-10-09T23:59:59.000Z

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401

Single-crystal X-ray and neutron diffraction investigations of the temperature dependence of the structure of the Tc = 10 K organic superconductor. kappa. -(ET) sub 2 Cu(NCS) sub 2. [where ET or BEDT-TTF = bis(ethylenedithio)tetrathiafulvalene, C sub 10 H sub 8 S sub 8  

Science Conference Proceedings (OSTI)

The crystal structure of {kappa}-(ET){sub 2}Cu(NCS){sub 2} (ET or BEDT-TTF = bis(ethylenedithio)tetrathiafulvalene, C{sub 10}H{sub 8}S{sub 8}) has been examined by single-crystal neutron and X-ray diffraction at temperatures between 298 and 15 K. Comparison of the low temperature ordered structures determined by use of X-ray and neutron diffraction with the previously reported crystallographically disordered room temperature X-ray structure indicates the avoidance of close H{center dot}{center dot}{center dot}H contacts as the reason for the conformational disorder of the terminal ethylene groups of the ET molecules at high temperatures. The space group is monoclinic noncentrosymmetric P2{sub 1}, Z = 2. Unit cell parameters at 118 K are a = 16.359(4), b = 8.418(2), c = 12.855(3) {angstrom}, {beta} = 111.21(2){degree}, and V = 1650.3(7) {angstrom}{sup 3}; at 15 K, a = 16.373(5), b = 8.375(3), c = 12.775(6) {angstrom}, {beta} = 111.45(4){degree}, and V = 1630(1) {angstrom}{sup 3}. The interlayer spacing a {center dot} sin {beta} remains constant upon cooling from 298 to 15 K even though the a axis increases slightly in length.

Schultz, A.J.; Beno, M.A.; Geiser, U.; Wang, H.H.; Kini, A.; Williams, J.M. (Argonne National Lab., IL (United States)); Myunghwan Whangbo (North Carolina State Univ., Raleigh (United States))

1991-10-01T23:59:59.000Z

402

X-rays Illuminate Ancient Archimedes Text  

NLE Websites -- All DOE Office Websites (Extended Search)

Related Links: Related Links: May 2005 Headlines TIP Article Press Release Walters Art Museum SSRL Home Page SLAC Home Page Stanford Home Page Tuesday, 31 May 2005 X-rays Illuminate Ancient Archimedes Text (contact: Uwe Bergmann, bergmann@slac.stanford.edu) Archimedes Figure Image provided by Will Noel, The Walters Art Museum An early transcription of Archimedes' mathematical theories has been brought to light through the probing of high-intensity x-rays at SSRL's BL6-2. The text contains part of the Method of Mechanical Theorems, one of Archimedes' most important works, which was probably copied out by a scribe in the tenth century. The parchment on which it was written was later scraped down and reused as pages in a twelfth century prayer book, producing a document known as a palimpsest (which comes from the Greek,

403

Sixth International Conference on X-ray Microscopy  

SciTech Connect

More than 180 participants from around the world crowded the Clark Kerr Campus of the University of California, Berkeley, from August 1-6, 1999 for the Sixth International Conference on X-Ray Microscopy (XRM99). Held every three years since 1983, the XRM conferences have become the primary international forum for the presentation and discussion of advances in high-spatial-resolution x-ray imaging and applications (including the use of x-ray spectroscopic and analytical techniques) in biological and medical sciences, environmental and soil sciences, and materials and surface sciences.

Robinson, Arthur L.

1999-08-23T23:59:59.000Z

404

Real Time in situ hard X-ray texture evolution during the annealing of rolled CuNi tapes  

E-Print Network (OSTI)

1 Real Time in situ hard X-ray texture evolution during the annealing of rolled CuNi tapes Antoine monochromators. It uses a white hard X ray beam and works in transmission geometry. The 2D detector allows, used as substrate for high temperature superconductor, is presented. hard X-rays; diffraction; in

Paris-Sud XI, Université de

405

Low dose hard x-ray contact microscopy assisted by a photoelectric conversion layer  

SciTech Connect

Hard x-ray contact microscopy provides images of dense samples at resolutions of tens of nanometers. However, the required beam intensity can only be delivered by synchrotron sources. We report on the use of a gold photoelectric conversion layer to lower the exposure dose by a factor of 40 to 50, allowing hard x-ray contact microscopy to be performed with a compact x-ray tube. We demonstrate the method in imaging the transmission pattern of a type of hard x-ray grating that cannot be fitted into conventional x-ray microscopes due to its size and shape. Generally the method is easy to implement and can record images of samples in the hard x-ray region over a large area in a single exposure, without some of the geometric constraints associated with x-ray microscopes based on zone-plate or other magnifying optics.

Gomella, Andrew; Martin, Eric W.; Lynch, Susanna K.; Wen, Han [Imaging Physics Laboratory, Biophysics and Biochemistry Center, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD, 20892 (United States); Morgan, Nicole Y. [Intramural Research Programs, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, MD, 20892 (United States)

2013-04-15T23:59:59.000Z

406

X-ray streak and framing camera techniques  

SciTech Connect

This paper reviews recent developments and applications of ultrafast diagnostic techniques for x-ray measurements. These techniques, based on applications of image converter devices, are already capable of significantly important resolution capabilities. Techniques capable of time resolution in the sub-nanosecond regime are being considered. Mechanical cameras are excluded from considerations as are devices using phosphors or fluors as x-ray converters.

Coleman, L.W.; Attwood, D.T.

1975-12-23T23:59:59.000Z

407

Femtosecond Time-Delay X-ray Holography  

NLE Websites -- All DOE Office Websites (Extended Search)

Time-Delay X-ray Holography Time-Delay X-ray Holography X-ray free-electron lasers (XFELs) will produce photon pulses with a unique and desirable combination of properties. Their short X-ray wavelengths allow penetration into materials and the ability to probe structure at and below the nanometer scale. Their ultra-short duration gives information about this structure at the fundamental time-scales of atoms and molecules. The extreme intensity of the pulses will allow this information to be acquired in a single shot, so that these studies can be carried out on non-repeatable processes or on weakly-scattering objects that will be modified by the pulse. A fourth property of XFEL pulses is their high transverse coherence, which brings the promise of decades of innovation in visible optics to the X-ray regime, such as holography, interferometry, and laser-based imaging. Making an effective use of XFEL pulses, however, will benefit from innovations that are new to both X-ray science and coherent optics. One such innovation is the new method of time-delay X-ray holography [i], recently demonstrated at the FLASH FEL at DESY in Hamburg, to measure the evolution of objects irradiated by intense pulses.

408

Diffraction Metrology and Standards  

Science Conference Proceedings (OSTI)

... and X-ray diffraction on two different synchrotron beamlines, at energies of 25 ... that allowed for the calibration of both line position and intensity as a ...

2012-10-09T23:59:59.000Z

409

X-ray emission from colliding laser plasmas  

SciTech Connect

Colliding Au, CD and Ti-Cr plasmas have been generated by illuminating two opposing foils each with a {approximately} 100J, 0.5 nsec, 2{omega} Nd-glass laser beam from the Trident laser facility at Los Alamos. The plasmas are being used to study plasma interactions which span the parameter regime from interpenetrating to collisional stagnation.