National Library of Energy BETA

Sample records for angle x-ray scattering

  1. Small Angle X-Ray Scattering Detector

    DOE Patents [OSTI]

    Hessler, Jan P.

    2004-06-15

    A detector for time-resolved small-angle x-ray scattering includes a nearly constant diameter, evacuated linear tube having an end plate detector with a first fluorescent screen and concentric rings of first fiber optic bundles for low angle scattering detection and an annular detector having a second fluorescent screen and second fiber optic bundles concentrically disposed about the tube for higher angle scattering detection. With the scattering source, i.e., the specimen under investigation, located outside of the evacuated tube on the tube's longitudinal axis, scattered x-rays are detected by the fiber optic bundles, to each of which is coupled a respective photodetector, to provide a measurement resolution, i.e., dq/q, where q is the momentum transferred from an incident x-ray to an x-ray scattering specimen, of 2% over two (2) orders of magnitude in reciprocal space, i.e., qmax/qmin approx=lO0.

  2. Small Angle X-Ray Scattering Detector

    DOE Patents [OSTI]

    Hessler, Jan P.

    2004-06-15

    A detector for time-resolved small-angle x-ray scattering includes a nearly constant diameter, evacuated linear tube having an end plate detector with a first fluorescent screen and concentric rings of first fiber optic bundles for low angle scattering detection and an annular detector having a second fluorescent screen and second fiber optic bundles concentrically disposed about the tube for higher angle scattering detection. With the scattering source, i.e., the specimen under investigation, located outside of the evacuated tube on the tube's longitudinal axis, scattered x-rays are detected by the fiber optic bundles, to each of which is coupled a respective photodetector, to provide a measurement resolution, i.e., dq/q, where q is the momentum transferred from an incident x-ray to an x-ray scattering specimen, of 2% over two (2) orders of magnitude in reciprocal space, i.e., q.sub.max /q.sub.min.congruent.100.

  3. Small-Angle X-Ray Scattering From RNA, Proteins, And Protein...

    Office of Scientific and Technical Information (OSTI)

    Small-Angle X-Ray Scattering From RNA, Proteins, And Protein Complexes Citation Details In-Document Search Title: Small-Angle X-Ray Scattering From RNA, Proteins, And Protein ...

  4. Small-angle X-ray scattering: a bridge between RNA secondary...

    Office of Scientific and Technical Information (OSTI)

    Small-angle X-ray scattering: a bridge between RNA secondary structures and three-dimensional topological structures Prev Next Title: Small-angle X-ray scattering: a bridge ...

  5. X-ray small-angle scattering from sputtered CeO{sub 2}/C bilayers

    SciTech Connect (OSTI)

    Haviar, S.; Dubau, M.; Khalakhan, I.; Vorokhta, M.; Matolinova, I.; Matolin, V.; Vales, V.; Endres, J.; Holy, V.; Buljan, M.; Bernstorff, S.

    2013-01-14

    Surface and interface morphology of cerium oxide/carbon bilayers used as thin-film catalysts is studied by grazing-incidence small-angle x-ray scattering, scanning electron microscopy, and atomic-force microscopy, and the dependence of the structural parameters on the thicknesses of the constituting layers is investigated. The applicability of x-ray scattering and its advantages over standard analytical methods are discussed.

  6. BIOISIS: Biological Macromolecules by Small Angle X-ray Scattering (SAXS)

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Tainer, John [Scripps Research Institute; Hura, Greg [LBNL; Rambo, Robert P. [LBNL

    BIOISIS is an open access database dedicated to the study of biological macromolecules by small angle X-ray scattering (SAXS). BIOISIS aims to become the complete source for the deposition, distribution and maintenance of small angle X-ray scattering data and technologies. The database is designed around the concept of an experiment and relates a specific experiment to a set of genes, organisms, computational models and experimental data. As of May 2012, BIOSIS contains 7,118 genes covering four different organisms. Forty-two modeled structures are available. Clicking on a structures reveals scattering curves, experimental conditions, and experimental values. The data are collected at Beamline 12.3.1 of the Advanced Light Source (ALS).[Copied with editing from http://www.bioisis.net/about

  7. BIOISIS: Biological Macromolecules by Small Angle X-ray Scattering (SAXS)

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Tainer, John [Scripps Research Institute; Hura, Greg [LBNL; Rambo, Robert P. [LBNL

    BIOISIS is an open access database dedicated to the study of biological macromolecules by small angle X-ray scattering (SAXS). BIOISIS aims to become the complete source for the deposition, distribution and maintenance of small angle X-ray scattering data and technologies. The database is designed around the concept of an ôexperimentö and relates a specific experiment to a set of genes, organisms, computational models and experimental data. As of May 2012, BIOSIS contains 7,118 genes covering four different organisms. Forty-two modeled structures are available. Clicking on a structures reveals scattering curves, experimental conditions, and experimental values. The data are collected at Beamline 12.3.1 of the Advanced Light Source (ALS).[Copied with editing from http://www.bioisis.net/about

  8. Small-angle X-ray Scattering from Magnetic Clusters and Structural Grains

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    in Magnetic Recording Media | Stanford Synchrotron Radiation Lightsource Small-angle X-ray Scattering from Magnetic Clusters and Structural Grains in Magnetic Recording Media Friday, July 31, 2015 Historically, areal density increases in longitudinal hard disk drive media technology have been driven by reduction of grain size. However, since its introduction in 2006, the perpendicular magnetic recording media grain size has remained more or less constant at around 9 nm. Perpendicular

  9. Wide angle x-ray scattering of proteins : effect of beam exposure on protein integrity.

    SciTech Connect (OSTI)

    Fischetti, R. F.; Rodi, D. J.; Mirza, A.; Makowski, L.; Illinois Inst. of Tech.

    2003-01-01

    Wide-angle X-ray scattering patterns from proteins in solution contain information relevant to the determination of protein fold. At relevant scattering angles, however, these data are weak, and the degree to which they might be used to categorize the fold of a protein is unknown. Preliminary work has been performed at the BioCAT insertion-device beamline at the Advanced Photon Source which demonstrates that one can collect X-ray scattering data from proteins in solution to spacings of at least 2.2 {angstrom} (q = 2.8 {angstrom}-1). These data are sensitive to protein conformational states, and are in good agreement with the scattering predicted by the program CRYSOL using the known three-dimensional atomic coordinates of the protein. An important issue in the exploitation of this technique as a tool for structural genomics is the extent to which the high intensity of X-rays available at third-generation synchrotron sources chemically or structurally damage proteins. Various data-collection protocols have been investigated demonstrating conditions under which structural degradation of even sensitive proteins can be minimized, making this technique a viable tool for protein fold categorization, the study of protein folding, unfolding, protein-ligand interactions and domain movement.

  10. Characterization of porous materials using combined small-angle X-ray and neutron scattering techniques

    SciTech Connect (OSTI)

    Hu, Naiping; Borkar, Neha; Kohls, Doug; Schaefer, Dale W. (UCIN)

    2014-09-24

    A combination of ultra small angle X-ray scattering (USAXS) and ultra small angle neutron scattering (USANS) is used to characterize porous materials. The analysis methods yield quantitative information, including the mean skeletal chord length, mean pore chord length, skeletal density, and composition. A mixed cellulose ester (MCE) membrane with a manufacturer-labeled pore size of 0.1 {mu}m was used as a model to elucidate the specifics of the method. Four approaches describing four specific scenarios (different known parameters and form of the scattering data) are compared. Pore chords determined using all four approaches are in good agreement with the scanning electron microscopy estimates but are larger than the manufacturer's nominal pore size. Our approach also gives the average chord of the skeletal solid (struts) of the membrane, which is also consistent for all four approaches. Combined data from USAXS and USANS gives the skeletal density and the strut composition.

  11. Imaging method based on attenuation, refraction and ultra-small-angle-scattering of x-rays

    DOE Patents [OSTI]

    Wernick, Miles N.; Chapman, Leroy Dean; Oltulu, Oral; Zhong, Zhong

    2005-09-20

    A method for detecting an image of an object by measuring the intensity at a plurality of positions of a transmitted beam of x-ray radiation emitted from the object as a function of angle within the transmitted beam. The intensity measurements of the transmitted beam are obtained by a crystal analyzer positioned at a plurality of angular positions. The plurality of intensity measurements are used to determine the angular intensity spectrum of the transmitted beam. One or more parameters, such as an attenuation property, a refraction property and a scatter property, can be obtained from the angular intensity spectrum and used to display an image of the object.

  12. Time Resolved Collapse of a Folding Protein Observed with Small Angle X-Ray Scattering

    SciTech Connect (OSTI)

    Pollack, L.; Tate, M. W.; Finnefrock, A. C.; Kalidas, C.; Trotter, S.; Darnton, N. C.; Lurio, L.; Austin, R. H.; Batt, C. A.; Gruner, S. M. (and others)

    2001-05-21

    High-intensity, ''pink'' beam from an undulator was used in conjunction with microfabricated rapid-fluid mixing devices to monitor the early events in protein folding with time resolved small angle x-ray scattering. This Letter describes recent work on the protein bovine {beta} -lactoglobulin where collapse from an expanded to a compact set of states was directly observed on the millisecond time scale. The role of chain collapse, one of the initial stages of protein folding, is not currently understood. The characterization of transient, compact states is vital in assessing the validity of theories and models of the folding process.

  13. The accurate assessment of small-angle X-ray scattering data

    SciTech Connect (OSTI)

    Grant, Thomas D.; Luft, Joseph R.; Carter, Lester G.; Matsui, Tsutomu; Weiss, Thomas M.; Martel, Anne; Snell, Edward H.

    2015-01-23

    Small-angle X-ray scattering (SAXS) has grown in popularity in recent times with the advent of bright synchrotron X-ray sources, powerful computational resources and algorithms enabling the calculation of increasingly complex models. However, the lack of standardized data-quality metrics presents difficulties for the growing user community in accurately assessing the quality of experimental SAXS data. Here, a series of metrics to quantitatively describe SAXS data in an objective manner using statistical evaluations are defined. These metrics are applied to identify the effects of radiation damage, concentration dependence and interparticle interactions on SAXS data from a set of 27 previously described targets for which high-resolution structures have been determined via X-ray crystallography or nuclear magnetic resonance (NMR) spectroscopy. Studies show that these metrics are sufficient to characterize SAXS data quality on a small sample set with statistical rigor and sensitivity similar to or better than manual analysis. The development of data-quality analysis strategies such as these initial efforts is needed to enable the accurate and unbiased assessment of SAXS data quality.

  14. The accurate assessment of small-angle X-ray scattering data

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Grant, Thomas D.; Luft, Joseph R.; Carter, Lester G.; Matsui, Tsutomu; Weiss, Thomas M.; Martel, Anne; Snell, Edward H.

    2015-01-23

    Small-angle X-ray scattering (SAXS) has grown in popularity in recent times with the advent of bright synchrotron X-ray sources, powerful computational resources and algorithms enabling the calculation of increasingly complex models. However, the lack of standardized data-quality metrics presents difficulties for the growing user community in accurately assessing the quality of experimental SAXS data. Here, a series of metrics to quantitatively describe SAXS data in an objective manner using statistical evaluations are defined. These metrics are applied to identify the effects of radiation damage, concentration dependence and interparticle interactions on SAXS data from a set of 27 previously described targetsmore » for which high-resolution structures have been determined via X-ray crystallography or nuclear magnetic resonance (NMR) spectroscopy. Studies show that these metrics are sufficient to characterize SAXS data quality on a small sample set with statistical rigor and sensitivity similar to or better than manual analysis. The development of data-quality analysis strategies such as these initial efforts is needed to enable the accurate and unbiased assessment of SAXS data quality.« less

  15. The accurate assessment of small-angle X-ray scattering data

    SciTech Connect (OSTI)

    Grant, Thomas D.; Luft, Joseph R.; Carter, Lester G.; Matsui, Tsutomu; Weiss, Thomas M.; Martel, Anne; Snell, Edward H.

    2015-01-01

    A set of quantitative techniques is suggested for assessing SAXS data quality. These are applied in the form of a script, SAXStats, to a test set of 27 proteins, showing that these techniques are more sensitive than manual assessment of data quality. Small-angle X-ray scattering (SAXS) has grown in popularity in recent times with the advent of bright synchrotron X-ray sources, powerful computational resources and algorithms enabling the calculation of increasingly complex models. However, the lack of standardized data-quality metrics presents difficulties for the growing user community in accurately assessing the quality of experimental SAXS data. Here, a series of metrics to quantitatively describe SAXS data in an objective manner using statistical evaluations are defined. These metrics are applied to identify the effects of radiation damage, concentration dependence and interparticle interactions on SAXS data from a set of 27 previously described targets for which high-resolution structures have been determined via X-ray crystallography or nuclear magnetic resonance (NMR) spectroscopy. The studies show that these metrics are sufficient to characterize SAXS data quality on a small sample set with statistical rigor and sensitivity similar to or better than manual analysis. The development of data-quality analysis strategies such as these initial efforts is needed to enable the accurate and unbiased assessment of SAXS data quality.

  16. Density of hydrophobically confined deeply cooled water investigated by small angle X-ray scattering

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Liu, Kao-Hsiang; Zhang, Yang; Jeng, U-Ser; Mou, Chung-Yuan

    2015-09-07

    The behavior of water near hydrophobic surfaces has attracted great attention due to chemical and geological applications. Here, we report small angle X-ray scattering (SAXS) studies of water confined in the hydrophobic nanoporous carbon material, CMK-1-14, from ambient to deeply cooled temperatures. Moreover, by monitoring the scattering intensity of the first Bragg peak, which is directly related to the scattering length density contrast between the carbon matrix and the confined water, the average density of the hydrophobically confined water was determined from 300 K to 150 K at ambient pressure. Furthermore, differential scanning calorimetry and X-ray diffraction measurements showed thatmore » the majority of such hydrophobically confined water did not crystallize in the investigated temperature range. By exploiting the fast speed of SAXS measurements and the continuous temperature ramping, the average density profile and the deduced thermal expansion coefficient (alpha(p)) were obtained. We found that the well-known density maximum of water at 277 K downshifted to 260 K, and the density minimum which has been observed in hydrophilic confinement disappeared. Additionally, the previously measured large density decreasing of 18% at low temperature was recalibrated to a more reasonable 10% instead. Consequently, the recalculated ap peak was found to be quite similar to that of the water confined in hydrophilic MCM-41-S-15 suggesting an intrinsic property of water, which does not sensitively depend on the confinement surface.« less

  17. Density of hydrophobically confined deeply cooled water investigated by small angle X-ray scattering

    SciTech Connect (OSTI)

    Liu, Kao-Hsiang; Zhang, Yang; Jeng, U-Ser; Mou, Chung-Yuan

    2015-09-07

    The behavior of water near hydrophobic surfaces has attracted great attention due to chemical and geological applications. Here, we report small angle X-ray scattering (SAXS) studies of water confined in the hydrophobic nanoporous carbon material, CMK-1-14, from ambient to deeply cooled temperatures. Moreover, by monitoring the scattering intensity of the first Bragg peak, which is directly related to the scattering length density contrast between the carbon matrix and the confined water, the average density of the hydrophobically confined water was determined from 300 K to 150 K at ambient pressure. Furthermore, differential scanning calorimetry and X-ray diffraction measurements showed that the majority of such hydrophobically confined water did not crystallize in the investigated temperature range. By exploiting the fast speed of SAXS measurements and the continuous temperature ramping, the average density profile and the deduced thermal expansion coefficient (alpha(p)) were obtained. We found that the well-known density maximum of water at 277 K downshifted to 260 K, and the density minimum which has been observed in hydrophilic confinement disappeared. Additionally, the previously measured large density decreasing of 18% at low temperature was recalibrated to a more reasonable 10% instead. Consequently, the recalculated ap peak was found to be quite similar to that of the water confined in hydrophilic MCM-41-S-15 suggesting an intrinsic property of water, which does not sensitively depend on the confinement surface.

  18. Density of hydrophobically confined deeply cooled water investigated by small angle X-ray scattering

    SciTech Connect (OSTI)

    Liu, Kao-Hsiang; Zhang, Yang; Jeng, U-Ser; Mou, Chung-Yuan

    2015-09-07

    Water’s behavior near hydrophobic surfaces has attracted great attention due to chemical and geological applications. Here, we report small angle X-ray scattering (SAXS) studies of water confined in the hydrophobic nanoporous carbon material, CMK-1-14, from ambient to deeply cooled temperatures. By monitoring the scattering intensity of the first Bragg peak, which is directly related to the scattering length density contrast between the carbon matrix and the confined water, the average density of the hydrophobically confined water was determined from 300 K to 150 K at ambient pressure. Furthermore, differential scanning calorimetry and X-ray diffraction measurements showed that the majority of such hydrophobically confined water did not crystallize in the investigated temperature range. By exploiting the fast speed of SAXS measurements and the continuous temperature ramping, the average density profile and the deduced thermal expansion coefficient (α{sub p}) were obtained. We found that the well-known density maximum of water at 277 K downshifted to 260 K, and the density minimum which has been observed in hydrophilic confinement disappeared. In addition, the previously measured large density decreasing of 18% at low temperature was recalibrated to a more reasonable 10% instead. Consequently, the recalculated α{sub p} peak was found to be quite similar to that of the water confined in hydrophilic MCM-41-S-15 suggesting an intrinsic property of water, which does not sensitively depend on the confinement surface.

  19. Ultrasmall-angle X-ray scattering analysis of photonic crystal structure

    SciTech Connect (OSTI)

    Abramova, V. V.; Sinitskii, A. S.; Grigor'eva, N. A.; Grigor'ev, S. V.; Belov, D. V.; Petukhov, A. V.; Mistonov, A. A.; Vasil'eva, A. V.; Tret'yakov, Yu. D.

    2009-07-15

    The results of an ultrasmall-angle X-ray scattering study of iron(III) oxide inverse opal thin films are presented. The photonic crystals examined are shown to have fcc structure with amount of stacking faults varying among the samples. The method used in this study makes it possible to easily distinguish between samples with predominantly twinned fcc structure and nearly perfect fcc stacking. The difference observed between samples fabricated under identical conditions is attributed to random layer stacking in the self-assembled colloidal crystals used as templates for fabricating the inverse opals. The present method provides a versatile tool for analyzing photonic crystal structure in studies of inverse opals made of various materials, colloidal crystals, and three-dimensional photonic crystals of other types.

  20. Structural Significance of Lipid Diversity as Studied by Small Angle Neutron and X-ray Scattering

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Kučerka, Norbert; Heberle, Frederick A.; Pan, Jianjun; Katsaras, John

    2015-09-21

    In this paper, we review recent developments in the rapidly growing field of membrane biophysics, with a focus on the structural properties of single lipid bilayers determined by different scattering techniques, namely neutron and X-ray scattering. The need for accurate lipid structural properties is emphasized by the sometimes conflicting results found in the literature, even in the case of the most studied lipid bilayers. Increasingly, accurate and detailed structural models require more experimental data, such as those from contrast varied neutron scattering and X-ray scattering experiments that are jointly refined with molecular dynamics simulations. This experimental and computational approach producesmore » robust bilayer structural parameters that enable insights, for example, into the interplay between collective membrane properties and its components (e.g., hydrocarbon chain length and unsaturation, and lipid headgroup composition). Finally, from model studies such as these, one is better able to appreciate how a real biological membrane can be tuned by balancing the contributions from the lipid’s different moieties (e.g., acyl chains, headgroups, backbones, etc.).« less

  1. Structural Significance of Lipid Diversity as Studied by Small Angle Neutron and X-ray Scattering

    SciTech Connect (OSTI)

    Kučerka, Norbert; Heberle, Frederick A.; Pan, Jianjun; Katsaras, John

    2015-09-21

    In this paper, we review recent developments in the rapidly growing field of membrane biophysics, with a focus on the structural properties of single lipid bilayers determined by different scattering techniques, namely neutron and X-ray scattering. The need for accurate lipid structural properties is emphasized by the sometimes conflicting results found in the literature, even in the case of the most studied lipid bilayers. Increasingly, accurate and detailed structural models require more experimental data, such as those from contrast varied neutron scattering and X-ray scattering experiments that are jointly refined with molecular dynamics simulations. This experimental and computational approach produces robust bilayer structural parameters that enable insights, for example, into the interplay between collective membrane properties and its components (e.g., hydrocarbon chain length and unsaturation, and lipid headgroup composition). Finally, from model studies such as these, one is better able to appreciate how a real biological membrane can be tuned by balancing the contributions from the lipid’s different moieties (e.g., acyl chains, headgroups, backbones, etc.).

  2. Grazing-incidence small-angle X-ray scattering: application to the study of quantum dot lattices

    SciTech Connect (OSTI)

    Buljan, Maja Radi?, Nikola; Bernstorff, Sigrid; Drai?, Goran; Bogdanovi?-Radovi?, Iva; Hol, Vclav

    2012-01-01

    The modelling of grazing-incidence small-angle X-ray scattering (GISAXS) from three-dimensional quantum dot lattices is described. The ordering of quantum dots in three-dimensional quantum dot lattices is investigated by grazing-incidence small-angle X-ray scattering (GISAXS). Theoretical models describing GISAXS intensity distributions for three general classes of lattices of quantum dots are proposed. The classes differ in the type of disorder of the positions of the quantum dots. The models enable full structure determination, including lattice type, lattice parameters, the type and degree of disorder in the quantum dot positions and the distributions of the quantum dot sizes. Applications of the developed models are demonstrated using experimentally measured data from several types of quantum dot lattices formed by a self-assembly process.

  3. Anomalous small-angle X-ray scattering of nanoporous two-phase atomistic models for amorphous silicon–germanium alloys

    SciTech Connect (OSTI)

    Chehaidar, A.

    2015-09-15

    The present work deals with a detailed analysis of the anomalous small-angle X-ray scattering in amorphous silicon–germanium alloy using the simulation technique. We envisage the nanoporous two-phase alloy model consisting in a mixture of Ge-rich and Ge-poor domains and voids at the nanoscale. By substituting Ge atoms for Si atoms in nanoporous amorphous silicon network, compositionally heterogeneous alloys are generated with various composition-contrasts between the two phases. After relaxing the as-generated structure, we compute its radial distribution function, and then we deduce by the Fourier transform technique its anomalous X-ray scattering pattern. Using a smoothing procedure, the computed X-ray scattering patterns are corrected for the termination errors due to the finite size of the model, allowing so a rigorous quantitative analysis of the anomalous small-angle scattering. Our simulation shows that, as expected, the anomalous small-angle X-ray scattering technique is a tool of choice for characterizing compositional heterogeneities coexisting with structural inhomogeneities in an amorphous alloy. Furthermore, the sizes of the compositional nanoheterogeneities, as measured by anomalous small-angle X-ray scattering technique, are X-ray energy independent. A quantitative analysis of the separated reduced anomalous small-angle X-ray scattering, as defined in this work, provided a good estimate of their size.

  4. Multiaxial deformation of polyethylene and polyethylene/clay nanocomposites: In situ synchrotron small angle and wide angle X-ray scattering study

    SciTech Connect (OSTI)

    Gurun, Bilge; Bucknall, David G.; Thio, Yonathan S.; Teoh, Chin Ching; Harkin-Jones, Eileen

    2013-01-10

    A unique in situ multiaxial deformation device has been designed and built specifically for simultaneous synchrotron small angle X-ray scattering (SAXS) and wide angle X-ray scattering (WAXS) measurements. SAXS and WAXS patterns of high-density polyethylene (HDPE) and HDPE/clay nanocomposites were measured in real time during in situ multiaxial deformation at room temperature and at 55 C. It was observed that the morphological evolution of polyethylene is affected by the existence of clay platelets as well as the deformation temperature and strain rate. Martensitic transformation of orthorhombic into monoclinic crystal phases was observed under strain in HDPE, which is delayed and hindered in the presence of clay nanoplatelets. From the SAXS measurements, it was observed that the thickness of the interlamellar amorphous region increased with increasing strain, which is due to elongation of the amorphous chains. The increase in amorphous layer thickness is slightly higher for the nanocomposites compared to the neat polymer.

  5. Turbulent pitch-angle scattering and diffusive transport of hard X-ray-producing electrons in flaring coronal loops

    SciTech Connect (OSTI)

    Kontar, Eduard P.; Bian, Nicolas H.; Emslie, A. Gordon; Vilmer, Nicole E-mail: emslieg@wku.edu

    2014-01-10

    Recent observations from RHESSI have revealed that the number of non-thermal electrons in the coronal part of a flaring loop can exceed the number of electrons required to explain the hard X-ray-emitting footpoints of the same flaring loop. Such sources cannot, therefore, be interpreted on the basis of the standard collisional transport model, in which electrons stream along the loop while losing their energy through collisions with the ambient plasma; additional physical processes, to either trap or scatter the energetic electrons, are required. Motivated by this and other observations that suggest that high-energy electrons are confined to the coronal region of the source, we consider turbulent pitch-angle scattering of fast electrons off low-frequency magnetic fluctuations as a confinement mechanism, modeled as a spatial diffusion parallel to the mean magnetic field. In general, turbulent scattering leads to a reduction of the collisional stopping distance of non-thermal electrons along the loop, and hence to an enhancement of the coronal hard X-ray source relative to the footpoints. The variation of source size L with electron energy E becomes weaker than the quadratic behavior pertinent to collisional transport, with the slope of L(E) depending directly on the mean free path ? associated with the non-collisional scattering mechanism. Comparing the predictions of the model with observations, we find that ? ? (10{sup 8}-10{sup 9}) cm for ?30 keV, less than the length of a typical flaring loop and smaller than, or comparable to, the size of the electron acceleration region.

  6. Small-angle x-ray scattering measurements of the microstructure of liquid helium mixtures adsorbed in aerogel

    SciTech Connect (OSTI)

    Lurio, L. B.; Mulders, N.; Paetkau, M.; Chan, M. H. W.; Mochrie, S. G. J. [Department of Physics, Northern Illinois University, DeKalb, Illinois 60115 (United States); Department of Physics, University of Delaware, Newark, Delaware 19716 (United States); Department of Physics and Astronomy, Okanagan College, British Columbia V1Y4X8 (Canada); Department of Physics, Pennsylvania State University, University Park, Pennsylvania 16802 (United States); Department of Physics, Yale University, New Haven, Connecticut 06511 (United States)

    2007-07-15

    Small-angle x-ray scattering (SAXS) was used to measure the microstructure of isotopic mixtures of {sup 3}He and {sup 4}He adsorbed into silica aerogels as a function of temperature and {sup 3}He concentration. The SAXS measurements could be well described by the formation of a nearly pure film of {sup 4}He which separates from the bulk mixture onto the aerogel strands and which thickens with decreasing temperature. Previous observations of a superfluid {sup 3}He-rich phase are consistent with superfluidity existing within this film phase. Observed differences between different density aerogels are explained in terms of the depletion of {sup 4}He from the bulk mixture due to film formation.

  7. Measurement of carbon condensates using small-angle x-ray scattering during detonation of the high explosive hexanitrostilbene

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Bagge-Hansen, M.; Lauderbach, L.; Hodgin, R.; Bastea, S.; Fried, L.; Jones, A.; van Buuren, T.; Hansen, D.; Benterou, J.; May, C.; et al

    2015-06-24

    In this study, the dynamics of carbon condensation in detonating high explosives remains controversial. Detonation model validation requires data for processes occurring at nanometer length scales on time scales ranging from nanoseconds to microseconds. A new detonation end station has been commissioned to acquire and provide time-resolved small-angle x-ray scattering (SAXS) from detonating explosives. Hexanitrostilbene (HNS) was selected as the first to investigate due to its ease of initiation using exploding foils and flyers, vacuum compatibility, high thermal stability, and stoichiometric carbon abundance that produces high carbon condensate yields. The SAXS data during detonation, collected with 300 ns time resolution,more » provide unprecedented signal fidelity over a broad q-range. This fidelity permits the first analysis of both the Guinier and Porod/power-law regions of the scattering profile during detonation, which contains information about the size and morphology of the resultant carbon condensate nanoparticles. To bolster confidence in these data, the scattering angle and intensity were additionally cross-referenced with a separate, highly calibrated SAXS beamline. The data show that HNS produces carbon particles with a radius of gyration of 2.7 nm in less than 400 ns after the detonation front has passed, and this size and morphology are constant over the next several microseconds. These data directly contradict previous pioneering work on RDX/TNT mixtures and TATB, where observations indicate significant particle growth (50% or more) continues over several microseconds. The power-law slope is about -3, which is consistent with a complex disordered, irregular, or folded sp2 sub-arrangement within a relatively monodisperse structure possessing radius of gyration of 2.7 nm after the detonation of HNS.« less

  8. Measurement of carbon condensation using small-angle x-ray scattering during detonation of the high explosive hexanitrostilbene

    SciTech Connect (OSTI)

    Bagge-Hansen, M.; Lauderbach, L. M.; Hodgin, R.; Bastea, S.; Fried, L.; Jones, A.; van Buuren, T.; Hansen, D.; Benterou, J.; May, C.; Graber, T.; Jensen, B. J.; Ilavsky, J.; Willey, T. M.

    2015-06-24

    The dynamics of carboncondensation in detonating high explosives remains controversial. Detonation model validation requires data for processes occurring at nanometer length scales on time scales ranging from nanoseconds to microseconds. A new detonation endstation has been commissioned to acquire and provide time-resolved small-angle x-ray scattering (SAXS) from detonating explosives. Hexanitrostilbene (HNS) was selected as the first to investigate due to its ease of initiation using exploding foils and flyers, vacuum compatibility, high thermal stability, and stoichiometric carbon abundance that produces high carbon condensate yields. The SAXS data during detonation, collected with 300 ns time resolution, provide unprecedented signal fidelity over a broad q-range. This fidelity permits the first analysis of both the Guinier and Porod/power-law regions of the scattering profile during detonation, which contains information about the size and morphology of the resultant carbon condensate nanoparticles. To bolster confidence in these data, the scattering angle and intensity were additionally cross-referenced with a separate, highly calibrated SAXS beamline. The data show that HNS produces carbon particles with a radius of gyration of 2.7 nm in less than 400 ns after the detonation front has passed, and this size and morphology are constant over the next several microseconds. These data directly contradict previous pioneering work on RDX/TNT mixtures and TATB, where observations indicate significant particle growth (50% or more) continues over several microseconds. As a result, the power-law slope is about –3, which is consistent with a complex disordered, irregular, or folded sp2 sub-arrangement within a relatively monodisperse structure possessing radius of gyration of 2.7 nm after the detonation of HNS.

  9. Poisson's ratio of collagen fibrils measured by small angle X-ray scattering of strained bovine pericardium

    SciTech Connect (OSTI)

    Wells, Hannah C.; Sizeland, Katie H.; Kayed, Hanan R.; Haverkamp, Richard G.; Kirby, Nigel; Hawley, Adrian; Mudie, Stephen T.

    2015-01-28

    Type I collagen is the main structural component of skin, tendons, and skin products, such as leather. Understanding the mechanical performance of collagen fibrils is important for understanding the mechanical performance of the tissues that they make up, while the mechanical properties of bulk tissue are well characterized, less is known about the mechanical behavior of individual collagen fibrils. In this study, bovine pericardium is subjected to strain while small angle X-ray scattering (SAXS) patterns are recorded using synchrotron radiation. The change in d-spacing, which is a measure of fibril extension, and the change in fibril diameter are determined from SAXS. The tissue is strained 0.25 (25%) with a corresponding strain in the collagen fibrils of 0.045 observed. The ratio of collagen fibril width contraction to length extension, or the Poisson's ratio, is 2.1 ± 0.7 for a tissue strain from 0 to 0.25. This Poisson's ratio indicates that the volume of individual collagen fibrils decreases with increasing strain, which is quite unlike most engineering materials. This high Poisson's ratio of individual fibrils may contribute to high Poisson's ratio observed for tissues, contributing to some of the remarkable properties of collagen-based materials.

  10. Protein Folding Dynamics Detected By Time-Resolved Synchrotron X-ray Small-Angle Scattering Technique

    SciTech Connect (OSTI)

    Fujisawa, Tetsuro; Takahashi, Satoshi [RIKEN Harima Institute, SPring-8 Center, Laboratory for Biometal Science, Hyogo 679-5148 (Japan); Institute for Protein Research, Osaka University Suita Osaka 565-0871/CREST, JST (Japan)

    2007-03-30

    The polypeptide collapse is an essential dynamics in protein folding. To understand the mechanism of the collapse, in situ observation of folding by various probes is necessary. The changes in secondary and tertiary structures in the folding process of globular proteins, whose chain lengths are less than 300 polypeptides, were observed by circular dichrosim and intrinsic fluorescence spectroscopies, respectively. On the other hand, those in protein compactness could be only detected by using time-resolved synchrotron x-ray small-angle scattering technique. The observed dynamics for several proteins with different topologies suggested a common folding mechanism termed 'collapse and search' dynamics, in which the polypeptide collapse precedes the formation of the native contact formation. In 'collapse and search' dynamics, the most outstanding feature lied in the compactness of the initial intermediates. The collapsed intermediates demonstrated the scaling relationship between radius of gyration (Rg) and chain length with a scaling exponent of 0.35 {+-} 0.11, which is close to the value (1/3) predicted by mechano-statistical theory for the collapsed globules of polymers in poor solvent. Thus, it was suggested that the initial collapse is caused by the coil-globule transition of polymers. Since the collapse is essential to the folding of larger proteins, further investigations on the collapse likely lead to an important insight into the protein folding phenomena.

  11. Mass fractal characteristics of silica sonogels as determined by small-angle x-ray scattering and nitrogen adsorption

    SciTech Connect (OSTI)

    Donatti, D.A.; Vollet, D.R.; Ibanez Ruiz, A.; Mesquita, A.; Silva, T.F.P. [Unesp-Universidade Estadual Paulista, IGCE, Departamento de Fisica, P.O. Box 178 CEP, 13500-970 Rio Claro, Sao Paulo (Brazil)

    2005-01-01

    A sample series of silica sonogels was prepared using different water-tetraethoxysilane molar ratio (r{sub w}) in the gelation step of the process in order to obtain aerogels with different bulk densities after the supercritical drying. The samples were analyzed by means of small-angle x-ray-scattering (SAXS) and nitrogen-adsorption techniques. Wet sonogels exhibit mass fractal structure with fractal dimension D increasing from {approx}2.1 to {approx}2.4 and mass-fractal correlation length {xi} diminishing from {approx}13 nm to {approx}2 nm, as r{sub w} is changed in the nominal range from 66 to 6. The process of obtaining aerogels from sonogels and heat treatment at 500 deg. C, in general, increases the mass-fractal dimension D, diminishes the characteristic length {xi} of the fractal structure, and shortens the fractal range at the micropore side for the formation of a secondary structured particle, apparently evolved from the original wet structure at a high resolution level. The overall mass-fractal dimension D of aerogels was evaluated as {approx}2.4 and {approx}2.5, as determined from SAXS and from pore-size distribution by nitrogen adsorption, respectively. The fine structure of the 'secondary particle' developed in the obtaining of aerogels could be described as a surface-mass fractal, with the correlated surface and mass-fractal dimensions decreasing from {approx}2.4 to {approx}2.0 and from {approx}2.7 to {approx}2.5, respectively, as the aerogel bulk density increases from 0.25 (r{sub w}=66) up to 0.91 g/cm{sup 3} (r{sub w}=6)

  12. Mass fractal characteristics of wet sonogels as determined by small-angle x-ray scattering and differential scanning calorimetry

    SciTech Connect (OSTI)

    Vollet, D. R.; Donatti, D. A.; Ibanez Ruiz, A.; Gatto, F. R. [Departamento de Fisica, Unesp-Univerisdade Estadual Paulista, IGCE, P.O. Box 178 CEP 13500-970 Rio Claro, SP (Brazil)

    2006-07-01

    Low density silica sonogels were prepared from acid sonohydrolysis of tetraethoxysilane. Wet gels were studied by small-angle x-ray scattering (SAXS) and differential scanning calorimetry (DSC). The DSC tests were carried out under a heating rate of 2 deg. C/min from -120 deg. C up to 30 deg. C. Aerogels were obtained by CO{sub 2} supercritical extraction and characterized by nitrogen adsorption and SAXS. The DSC thermogram displays two distinct endothermic peaks. The first, a broad peak extending from about -80 deg. C up to practically 0 deg. C, was associated to the melting of ice nanocrystals with a crystal size distribution with 'pore' diameter ranging from 1 or 2 nm up to about 60 nm, as estimated from Thomson's equation. The second, a sharp peak with onset temperature close to 0 deg. C, was attributed to the melting of macroscopic crystals. The DSC incremental 'nanopore' volume distribution is in reasonable agreement with the incremental pore volume distribution of the aerogel as determined from nitrogen adsorption. No macroporosity was detected by nitrogen adsorption, probably because the adsorption method applies stress on the sample during measurement, leading to a underestimation of pore volume, or because often positive curvature of the solid surface is in aerogels, making the nitrogen condensation more difficult. According to the SAXS results, the solid network of the wet gels behaves as a mass fractal structure with mass fractal dimension D=2.20{+-}0.01 in a characteristic length scale below {xi}=7.9{+-}0.1 nm. The mass fractal characteristics of the wet gels have also been probed from DSC data by means of an earlier applied modeling for generation of a mass fractal from the incremental ''pore'' volume distribution curves. The results are shown to be in interesting agreement with the results from SAXS.

  13. Microstructure of amorphous-silicon-based solar cell materials by small-angle x-ray scattering. Annual subcontract report, 6 April 1994--5 April 1995

    SciTech Connect (OSTI)

    Williamson, D.L.

    1995-08-01

    The general objective of this research is to provide detailed microstructural information on the amorphous-silicon-based, thin-film materials under development for improved multijunction solar cells. The experimental technique used is small-angle x-ray scattering (SAXS) providing microstructural data on microvoid fractions, sizes, shapes, and their preferred orientations. Other microstructural features such as alloy segregation, hydrogen-rich clusters and alloy short-range order are probed.

  14. Neutron and X-ray Scattering

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Neutron and X-ray Scattering Neutron and X-ray Scattering When used together, neutrons and high-energy x-rays provide a supremely powerful scientific tool for mining details about the structure of materials. Combining neutrons and high-energy x-rays to explore the frontiers of materials in extreme environments. Illuminating previously inaccessible time and spatial scales. Enabling in situ research to design, discover, and control materials. Get Expertise Donald Brown Email Pushing the limits of

  15. Ultra-small-angle X-ray scattering study of second- phase particles in heat-treated Zircaloy-4

    SciTech Connect (OSTI)

    Srirangam, Prakash; Idrees, Yasir; Ilavsky, Jan; Daymond, Mark R.

    2015-01-01

    The ultra-small-angle X-ray scattering (USAXS) technique has been used to investigate and to quantify the morphology and size distribution of secondphase particles in Zircaloy-4 under various heat-treatment conditions. The alloy samples were solutionized in the phase field at 1293 K for 15 min and then cooled at different rates, including water quenching, air cooling and furnace cooling. The water-quenched samples were subsequently subjected to a thermal aging treatment at 873 K for different aging times (30, 60, 120 and 300 min). The USAXS results show that water quenching and air cooling from the phase field produces a narrow size distribution of fine-size precipitates with an average diameter of 300–800 A ° , while furnace cooling resulted in coarsening of the particles, with a broad size distribution having an average precipitate size of 600–1200 A ° . Further, the furnace-cooled sample shows a higher volume fraction of particles than the water-quenched or air-cooled sample. The USAXS results on the quenched then aged samples show that aging at 873 K for 10 min resulted in very fine size precipitates with an average diameter of 200–350 A ° . A rapid precipitation with the highest number density of second-phase particles amongst all the heat-treated samples (4.3 1020 m3) was observed in the sample aged for 10 min at 873 K. Particles of larger size and with a broad size distribution were observed in the sample aged at 873 K for 300 min. A bimodal type of particle size distribution was observed in all the heat-treated samples. Important parameters in the characterization of second-phase particles, such as the average size, size distribution, volume fraction and number density, were evaluated and quantified. These parameters are discussed for both heat-treated and aged specimens. Transmission and scanning transmission electron microscopy characterization were carried out on all heat-treated samples, to assist in interpretation and to substantiate the

  16. Fluctuation X-Ray Scattering

    SciTech Connect (OSTI)

    Saldin, PI: D. K.; Co-I's: J. C. H. Spence and P. Fromme

    2013-01-25

    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

  17. SXST 2014 - 7th SSRL School on Synchrotron X-Ray Scattering Techniques

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    important techniques including small angle scattering, thin-film scattering, powder diffraction, structure refinement and surface x-ray scattering. The school will address topics...

  18. Ray tracing flux calculation for the small and wide angle x-ray...

    Office of Scientific and Technical Information (OSTI)

    Ray tracing flux calculation for the small and wide angle x-ray scattering diffraction station at the SESAME synchrotron radiation facility Citation Details In-Document Search ...

  19. Interrogation of Surface, Skin, and Core Orientation in Thermotropic Liquid-Crystalline Copolyester Moldings by Near-Edge X-ray Absorption Fine Structure and Wide-Angle X-ray Scattering

    SciTech Connect (OSTI)

    Rendon,S.; Bubeck, R.; Thomas, L.; Burghardt, W.; Hexemer, A.; Fischer, D.

    2007-01-01

    Injection molding thermotropic liquid-crystalline polymers (TLCPs) usually results in the fabrication of molded articles that possess complex states of orientation that vary greatly as a function of thickness. 'Skin-core' morphologies are often observed in TLCP moldings. Given that both 'core' and 'skin' orientation states may often differ both in magnitude and direction, deconvolution of these complex orientation states requires a method to separately characterize molecular orientation in the surface region. A combination of two-dimensional wide-angle X-ray scattering (WAXS) in transmission and near-edge X-ray absorption fine structure (NEXAFS) spectroscopy is used to probe the molecular orientation in injection molded plaques fabricated from a 4,4'-dihydroxy-{alpha}-methylstilbene (DH{alpha}MS)-based thermotropic liquid crystalline copolyester. Partial electron yield (PEY) mode NEXAFS is a noninvasive ex situ characterization tool with exquisite surface sensitivity that samples to a depth of 2 nm. The effects of plaque geometry and injection molding processing conditions on surface orientation in the regions on- and off- axis to the centerline of injection molded plaques are presented and discussed. Quantitative comparisons are made between orientation parameters obtained by NEXAFS and those from 2D WAXS in transmission, which are dominated by the microstructure in the skin and core regions. Some qualitative comparisons are also made with 2D WAXS results from the literature.

  20. Ray tracing flux calculation for the small and wide angle x-ray scattering diffraction station at the SESAME synchrotron radiation facility

    SciTech Connect (OSTI)

    Salah, Wa'el; Sanchez del Rio, M.; Hoorani, H.

    2009-09-15

    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).

  1. Crystal Structures and Small-angle X-ray Scattering Analysis of UDP-galactopyranose Mutase from the Pathogenic Fungus Aspergillus fumigatus

    SciTech Connect (OSTI)

    Dhatwalia, Richa; Singh, Harkewal; Oppenheimer, Michelle; Karr, Dale B.; Nix, Jay C.; Sobrado, Pablo; Tanner, John J.

    2015-10-15

    UDP-galactopyranose mutase (UGM) is a flavoenzyme that catalyzes the conversion of UDP-galactopyranose to UDP-galactofuranose, which is a central reaction in galactofuranose biosynthesis. Galactofuranose has never been found in humans but is an essential building block of the cell wall and extracellular matrix of many bacteria, fungi, and protozoa. The importance of UGM for the viability of many pathogens and its absence in humans make UGM a potential drug target. Here we report the first crystal structures and small-angle x-ray scattering data for UGM from the fungus Aspergillus fumigatus, the causative agent of aspergillosis. The structures reveal that Aspergillus UGM has several extra secondary and tertiary structural elements that are not found in bacterial UGMs yet are important for substrate recognition and oligomerization. Small-angle x-ray scattering data show that Aspergillus UGM forms a tetramer in solution, which is unprecedented for UGMs. The binding of UDP or the substrate induces profound conformational changes in the enzyme. Two loops on opposite sides of the active site move toward each other by over 10 {angstrom} to cover the substrate and create a closed active site. The degree of substrate-induced conformational change exceeds that of bacterial UGMs and is a direct consequence of the unique quaternary structure of Aspergillus UGM. Galactopyranose binds at the re face of the FAD isoalloxazine with the anomeric carbon atom poised for nucleophilic attack by the FAD N5 atom. The structural data provide new insight into substrate recognition and the catalytic mechanism and thus will aid inhibitor design.

  2. Extracting magnetic cluster size and its distributions in advanced perpendicular recording media with shrinking grain size using small angle x-ray scattering

    SciTech Connect (OSTI)

    Mehta, Virat; Ikeda, Yoshihiro; Takano, Ken; Terris, Bruce D.; Hellwig, Olav; Wang, Tianhan; Wu, Benny; Graves, Catherine; Dürr, Hermann A.; Scherz, Andreas; Stöhr, Jo

    2015-05-18

    We analyze the magnetic cluster size (MCS) and magnetic cluster size distribution (MCSD) in a variety of perpendicular magnetic recording (PMR) media designs using resonant small angle x-ray scattering at the Co L{sub 3} absorption edge. The different PMR media flavors considered here vary in grain size between 7.5 and 9.5 nm as well as in lateral inter-granular exchange strength, which is controlled via the segregant amount. While for high inter-granular exchange, the MCS increases rapidly for grain sizes below 8.5 nm, we show that for increased amount of segregant with less exchange the MCS remains relatively small, even for grain sizes of 7.5 and 8 nm. However, the MCSD still increases sharply when shrinking grains from 8 to 7.5 nm. We show evidence that recording performance such as signal-to-noise-ratio on the spin stand correlates well with the product of magnetic cluster size and magnetic cluster size distribution.

  3. In situ ultra-small-angle X-ray scattering study under uniaxial stretching of colloidal crystals prepared by silica nanoparticles bearing hydrogen-bonding polymer grafts

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Ishige, Ryohei; Williams, Gregory A.; Higaki, Yuji; Ohta, Noboru; Sato, Masugu; Takahara, Atsushi; Guan, Zhibin

    2016-04-19

    A molded film of single-component polymer-grafted nanoparticles (SPNP), consisting of a spherical silica core and densely grafted polymer chains bearing hydrogen-bonding side groups capable of physical crosslinking, was investigated byin situultra-small-angle X-ray scattering (USAXS) measurement during a uniaxial stretching process. Static USAXS revealed that the molded SPNP formed a highly oriented twinned face-centered cubic (f.c.c.) lattice structure with the [11-1] plane aligned nearly parallel to the film surface in the initial state. Structural analysis ofin situUSAXS using a model of uniaxial deformation induced by rearrangement of the nanoparticles revealed that the f.c.c. lattice was distorted in the stretching direction inmore » proportion to the macroscopic strain until the strain reached 35%, and subsequently changed into other f.c.c. lattices with different orientations. The lattice distortion and structural transition behavior corresponded well to the elastic and plastic deformation regimes, respectively, observed in the stress–strain curve. The attractive interaction of the hydrogen bond is considered to form only at the top surface of the shell and then plays an effective role in cross-linking between nanoparticles. The rearrangement mechanism of the nanoparticles is well accounted for by a strong repulsive interaction between the densely grafted polymer shells of neighboring particles.« less

  4. Morphological transformations in the magnetite biomineralizing protein Mms6 in iron solutions: A small-angle x-ray scattering study

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Zhang, Honghu; Liu, Xunpei; Feng, Shuren; Wang, Wenjie; Schmidt-Rohr, Klaus; Akinc, Mufit; Nilsen-Hamilton, Marit; Vaknin, David; Mallapragada, Surya

    2015-02-10

    In this study, magnetotactic bacteria that produce magnetic nanocrystals of uniform size and well-defined morphologies have inspired the use of biomineralization protein Mms6 to promote formation of uniform magnetic nanocrystals in vitro. Small angle X-ray scattering (SAXS) studies in physiological solutions reveal that Mms6 forms compact globular three-dimensional (3D) micelles (approximately 10 nm in diameter) that are, to a large extent, independent of concentration. In the presence of iron ions in the solutions, the general micellar morphology is preserved, however, with associations among micelles that are induced by iron ions. Compared with Mms6, the m2Mms6 mutant (with the sequence ofmore » hydroxyl/carboxyl containing residues in the C-terminal domain shuffled) exhibits subtle morphological changes in the presence of iron ions in solutions. The analysis of the SAXS data is consistent with a hierarchical core–corona micellar structure similar to that found in amphiphilic polymers. The addition of ferric and ferrous iron ions to the protein solution induces morphological changes in the micellar structure by transforming the 3D micelles into objects of reduced dimensionality of 2, with fractal-like characteristics (including Gaussian-chain-like) or, alternatively, platelet-like structures.« less

  5. Morphological transformations in the magnetite biomineralizing protein Mms6 in iron solutions: A small-angle x-ray scattering study

    SciTech Connect (OSTI)

    Zhang, Honghu; Liu, Xunpei; Feng, Shuren; Wang, Wenjie; Schmidt-Rohr, Klaus; Akinc, Mufit; Nilsen-Hamilton, Marit; Vaknin, David; Mallapragada, Surya

    2015-02-10

    In this study, magnetotactic bacteria that produce magnetic nanocrystals of uniform size and well-defined morphologies have inspired the use of biomineralization protein Mms6 to promote formation of uniform magnetic nanocrystals in vitro. Small angle X-ray scattering (SAXS) studies in physiological solutions reveal that Mms6 forms compact globular three-dimensional (3D) micelles (approximately 10 nm in diameter) that are, to a large extent, independent of concentration. In the presence of iron ions in the solutions, the general micellar morphology is preserved, however, with associations among micelles that are induced by iron ions. Compared with Mms6, the m2Mms6 mutant (with the sequence of hydroxyl/carboxyl containing residues in the C-terminal domain shuffled) exhibits subtle morphological changes in the presence of iron ions in solutions. The analysis of the SAXS data is consistent with a hierarchical core–corona micellar structure similar to that found in amphiphilic polymers. The addition of ferric and ferrous iron ions to the protein solution induces morphological changes in the micellar structure by transforming the 3D micelles into objects of reduced dimensionality of 2, with fractal-like characteristics (including Gaussian-chain-like) or, alternatively, platelet-like structures.

  6. Characterization of nanostructured zirconia prepared by hydrolysis and reverse micelle synthesis by small-angle neutron and X-ray scattering

    SciTech Connect (OSTI)

    Thiyagarajan, P.; Li, X.; Littrell, K.; Seifert, S.; Csencsits, R.; Loong, C.

    1999-12-07

    Low temperature techniques such as hydrolysis and reverse micelle syntheses provide the opportunity to determine the relationship between the structural properties and preparation conditions of zirconia powders as well as to tailor their physicochemical properties. The authors have performed small-angle neutron and synchrotron X-ray scattering (SANS and SAXS) experiments to study the nucleation and organization of zirconia nanoparticles via different preparation routes. First, the formation of reverse micelles in individual and mixed solutions of (ZrOCl{sub 2}+D{sub 2}O)/AOT/C{sub 6}D{sub 5}CD{sub 3}, and (NH{sub 4}OH+H{sub 2}O)/AOT/C{sub 6}D{sub 5}CD{sub 3} systems at water/AOT molar ratio of 20 was characterized. Second, the aggregation of zirconia gels obtained from the reaction of the reverse micelle solutions after heat treatments was studied. Third, the nanostructure of zirconia powders prepared by the reverse micelle method is compared with the corresponding powders prepared by hydrolysis after different heat treatments.

  7. Inelastic X-ray and Nuclear Resonant Scattering | Advanced Photon...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    XSD-IXN XSD-IXN Home Staff Inelastic X-ray and Nuclear Resonant Scattering The Inelastic X-ray and Nuclear Resonant Scattering group operates beamlines at APS Sectors 3, 9 and 30....

  8. In-Situ Monitoring of the Microstructure of TATB-based Explosive Formulations During Temperature Cycling using Ultra-small Angle X-ray Scattering

    SciTech Connect (OSTI)

    Willey, T M; Hoffman, D M; van Buuren, T; Lauderbach, L; Ilavsky, J; Gee, R H; Maiti, A; Overturf, G; Fried, L

    2008-02-06

    TATB (1,3,5 triamino-2,4,6-trinitrobenzene), an extremely insensitive explosive, is used both in plastic-bonded explosives (PBXs) and as an ultra-fine pressed powder (UFTATB). With both PBXs and UFTATB, an irreversible expansion occurs with temperature cycling known as ratchet growth. In TATB-based explosives using Kel-F 800 as binder (LX-17 and PBX-9502), additional voids, sizes hundreds of nanometers to a few microns account for much of the volume expansion caused by temperature cycling. These voids are in the predicted size regime for hot-spot formation during ignition and detonation, and thus an experimental measure of these voids is important feedback for hot-spot theory and for determining the relationship between void size distributions and detonation properties. Also, understanding the mechanism of ratchet growth allows future choice of explosive/binder mixtures to minimize these types of changes to explosives, further extending PBX shelf life. This paper presents the void size distributions of LX-17, UFTATB, and PBXs using commercially available Cytop M, Cytop A, and Hyflon AD60 binders during temperature cycling between -55 C and 70 C. These void size distributions are derived from ultra-small angle x-ray scattering (USAXS), a technique sensitive to structures from about 10 nm to about 2 mm. Structures with these sizes do not appreciably change in UFTATB, indicating voids or cracks larger than a few microns appear in UFTATB during temperature cycling. Compared to Kel-F 800 binders, Cytop M and Cytop A show relatively small increases in void volume from 0.9% to 1.3% and 0.6% to 1.1%, respectively, while Hyflon fails to prevent irreversible volume expansion (1.2% to 4.6%). Computational mesoscale models of ratchet growth and binder wetting and adhesion properties point to mechanisms of ratchet growth, and are discussed in combination with the experimental results.

  9. Small-angle x-ray scattering studies of the porosity of coals and chars. Quarterly progress report, July 1-September 30, 1980

    SciTech Connect (OSTI)

    Schmidt, P.W.

    1980-09-01

    Considerable effort has been devoted to checking and verifying some of the preliminary data reported previously. The technique employed in the past for measuring the x-ray transmission of the samples has been modified to provide more accurate values of the transmission. These transmission measurements are important for quantitative interpretation of the scattering data both because they are needed to determine the amount of background scattering that must be subtracted from a measured scattering curve and also because the value of the transmission is required for calculating the specific surface from the scattering data. Previous determinations of the specific surface have been checked and modified when corrected transmission values made recalculation necessary. Evaluation of the specific surface from the scattering data also requires a measurement of the absolute scattered intensity, or scattering cross section. In other words, the fraction of the incident radiation which is scattered must be known. For this scattering investigation of coals, the absolute intensity for the scattering system was determined by measurement of the scattering from a colloidal silica suspension. The details of this technique are described by I.S. Patel and P.W. Schmidt, J. Appl. Cryst. 4, 50 to 55. (1971).

  10. Sector 3 : High Resolution X-ray Scattering | Advanced Photon...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    & workshops IXN Group Useful Links Current APS status ESAF System GUP System X-Ray Science Division My APS Portal Sector 3 : High Resolution X-ray Scattering Sector 3 is...

  11. Magnetism studies using resonant, coherent, x-ray scattering | Stanford

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Synchrotron Radiation Lightsource Magnetism studies using resonant, coherent, x-ray scattering Monday, September 10, 2012 - 10:00am SLAC, Bldg. 137, Room 226 Keoki Seu Seminar: With the advent of free electron lasers there has been interest in using coherent x-rays to probe condensed matter systems. Resonant scattering with x-rays allow elemental specificity with magnetic contrast, and coherent light leads to speckle in the scattered pattern due to interference from waves exiting the sample.

  12. Structure of low-density nanoporous dielectrics revealed by low-vacuum electron microscopy and small-angle x-ray scattering

    SciTech Connect (OSTI)

    Kucheyev, S O; Toth, M; Baumann, T F; Hamza, A V; Ilavsky, J; Knowles, W R; Thiel, B L; Tileli, V; van Buuren, T; Wang, Y M; Willey, T M

    2006-06-05

    We use low-vacuum scanning electron microscopy to image directly the ligament and pore size and shape distributions of representative aerogels over a wide range of length scales ({approx} 10{sup 0}-10{sup 5} nm). The images are used for unambiguous, real-space interpretation of small-angle scattering data for these complex nanoporous systems.

  13. Resonant x-ray magnetic scattering in holmium

    SciTech Connect (OSTI)

    Gibbs, D.

    1991-01-01

    We review the results of resonant x-ray magnetic scattering experiments on the rare earth metal holmium. When the incident incident x-ray energy is tuned near the L{sub III} absorption edge, large resonant enhancements of the magnetic scattering and resonant integer harmonics are observed. These results are analyzed within the theory of x-ray resonance exchange scattering assuming electric dipole (2p {yields} 5d) and quadrupole (2p {yields} 4f) transitions among atomic orbitals. 30 refs., 5 figs.

  14. Intensity Pattern of Diffuse X-Ray Scattering From Thermally...

    Office of Scientific and Technical Information (OSTI)

    Populated Phonons in Fcc d-Pu-Ga Citation Details In-Document Search Title: Intensity Pattern of Diffuse X-Ray Scattering From Thermally Populated Phonons in Fcc d-Pu-Ga ...

  15. Linear Dichroism in Resonant Inelastic X-Ray Scattering to Molecular

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Spin-Orbit States Linear Dichroism in Resonant Inelastic X-Ray Scattering to Molecular Spin-Orbit States Linear Dichroism in Resonant Inelastic X-Ray Scattering to Molecular Spin-Orbit States Print Thursday, 17 December 2009 13:47 Schematic representation of linear dichroism observed in KL x-ray emission. Coupling between the spin-orbit interaction and the molecular field, oriented along the chemical bond, leads to different spin-orbit ratios as a function of the angle between the incoming

  16. Probing Spatial, Electronic Structures with X-ray Scattering, Spectroscopic

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Techniques | Stanford Synchrotron Radiation Lightsource Probing Spatial, Electronic Structures with X-ray Scattering, Spectroscopic Techniques Wednesday, September 5, 2012 - 10:45am SLAC, Bldg. 137, Room 226 Gang Chen Seminar: Structures at atomic scales are traditionally determined through X-ray crystallography that amplifies scattering intensities by introducing spatial periodicity. For amorphous materials and many macromolecules, such as viruses, proteins and biofilms, it is hard to

  17. Wide-angle point-to-point x-ray imaging with almost arbitrarily...

    Office of Scientific and Technical Information (OSTI)

    Wide-angle point-to-point x-ray imaging with almost arbitrarily large angles of incidence Citation Details In-Document Search Title: Wide-angle point-to-point x-ray imaging with ...

  18. High performance x-ray anti-scatter grid

    DOE Patents [OSTI]

    Logan, Clinton M.

    1995-01-01

    An x-ray anti-scatter grid for x-ray imaging, particularly for screening mammography, and method for fabricating same, x-rays incident along a direct path pass through a grid composed of a plurality of parallel or crossed openings, microchannels, grooves, or slots etched in a substrate, such as silicon, having the walls of the microchannels or slots coated with a high opacity material, such as gold, while x-rays incident at angels with respect to the slots of the grid, arising from scatter, are blocked. The thickness of the substrate is dependent on the specific application of the grid, whereby a substrate of the grid for mammography would be thinner than one for chest radiology. Instead of coating the walls of the slots, such could be filed with an appropriate liquid, such as mercury.

  19. High performance x-ray anti-scatter grid

    DOE Patents [OSTI]

    Logan, C.M.

    1995-05-23

    Disclosed are an x-ray anti-scatter grid for x-ray imaging, particularly for screening mammography, and method for fabricating same, x-rays incident along a direct path pass through a grid composed of a plurality of parallel or crossed openings, microchannels, grooves, or slots etched in a substrate, such as silicon, having the walls of the microchannels or slots coated with a high opacity material, such as gold, while x-rays incident at angels with respect to the slots of the grid, arising from scatter, are blocked. The thickness of the substrate is dependent on the specific application of the grid, whereby a substrate of the grid for mammography would be thinner than one for chest radiology. Instead of coating the walls of the slots, such could be filed with an appropriate liquid, such as mercury. 4 Figs.

  20. Imaging X-ray Thomson Scattering Spectrometer Design and Demonstration

    SciTech Connect (OSTI)

    Gamboa, E.J.; Huntington, C.M.; Trantham, M.R.; Keiter, P.A; Drake, R.P.; Montgomery, David; Benage, John F.; Letzring, Samuel A.

    2012-05-04

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

  1. Structural characterization of Green River oil-shale at high-pressure using pair distribution function analysis and small angle x-ray scattering.

    SciTech Connect (OSTI)

    Locke, D. R.; Chupas, P. J.; Chapman, K. W.; Pugmire, R. J.; Winans, R. E.; Univ. of Utah

    2008-01-01

    The compression behavior of a silicate-rich oil shale from the Green River formation in the pressure range 0.0-2.4 GPa was studied using in situ high pressure X-ray pair distribution function (PDF) measurements for the sample contained within a Paris-Edinburgh cell. The real-space local structural information in the PDF, G(r), was used to evaluate the compressibility of the oil shale. Specifically, the pressure-induced reduction in the medium- to long-range atom distances (6-20 {angstrom}) yielded an average sample compressibility corresponding to a bulk modulus of ca. 61-67 GPa. A structural model consisting of a three phase mixture of the principal crystalline oil shale components (quartz, albite and Illite) provided a good fit to the ambient pressure PDF data (R 30.7%). Indeed the features in the PDF beyond 6 {angstrom}, were similarly well fit by a single phase model of the highest symmetry, highly crystalline quartz component.

  2. Focusing polycapillary to reduce parasitic scattering for inelastic x-ray measurements at high pressure

    SciTech Connect (OSTI)

    Chow, P. Xiao, Y. M.; Rod, E.; Bai, L. G.; Shen, G. Y.; Sinogeikin, S.; Gao, N.; Ding, Y.; Mao, H.-K.

    2015-07-15

    The double-differential scattering cross-section for the inelastic scattering of x-ray photons from electrons is typically orders of magnitude smaller than that of elastic scattering. With samples 10-100 μm size in a diamond anvil cell at high pressure, the inelastic x-ray scattering signals from samples are obscured by scattering from the cell gasket and diamonds. One major experimental challenge is to measure a clean inelastic signal from the sample in a diamond anvil cell. Among the many strategies for doing this, we have used a focusing polycapillary as a post-sample optic, which allows essentially only scattered photons within its input field of view to be refocused and transmitted to the backscattering energy analyzer of the spectrometer. We describe the modified inelastic x-ray spectrometer and its alignment. With a focused incident beam which matches the sample size and the field of view of polycapillary, at relatively large scattering angles, the polycapillary effectively reduces parasitic scattering from the diamond anvil cell gasket and diamonds. Raw data collected from the helium exciton measured by x-ray inelastic scattering at high pressure using the polycapillary method are compared with those using conventional post-sample slit collimation.

  3. Operational properties of fluctuation X-ray scattering data

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Malmerberg, Erik; Kerfeld, Cheryl A.; Zwart, Petrus H.

    2015-03-20

    X-ray scattering images collected on timescales shorter than rotation diffusion times using a (partially) coherent beam result in a significant increase in information content in the scattered data. These measurements, named fluctuation X-ray scattering (FXS), are typically performed on an X-ray free-electron laser (XFEL) and can provide fundamental insights into the structure of biological molecules, engineered nanoparticles or energy-related mesoscopic materials beyond what can be obtained with standard X-ray scattering techniques. In order to understand, use and validate experimental FXS data, the availability of basic data characteristics and operational properties is essential, but has been absent up to this point.more » In this communication, an intuitive view of the nature of FXS data and their properties is provided, the effect of FXS data on the derived structural models is highlighted, and generalizations of the Guinier and Porod laws that can ultimately be used to plan experiments and assess the quality of experimental data are presented.« less

  4. RESONANT INELASTIC X-RAY SCATTERING FROM TRANSITION METAL OXIDES.

    SciTech Connect (OSTI)

    HILL,J.P.

    1999-08-23

    Recent developments in hard x-ray resonant inelastic x-ray scattering as a probe of strongly correlated systems are reviewed. Particular attention is paid to studies of Nd{sub 2}CuO{sub 4}. A charge transfer excitation is observed when the incident photon energy is tuned in the vicinity of the copper K-edge. It is shown that the presence of resonant enhancements is controlled by the polarization dependence of the excitation process and by the overlap between a given intermediate state and the particular excitation being studied. This latter observation has shed light on the non-local effects present in certain intermediate states.

  5. Crystal defect studies using x-ray diffuse scattering

    SciTech Connect (OSTI)

    Larson, B.C.

    1980-01-01

    Microscopic lattice defects such as point (single atom) defects, dislocation loops, and solute precipitates are characterized by local electronic density changes at the defect sites and by distortions of the lattice structure surrounding the defects. The effect of these interruptions of the crystal lattice on the scattering of x-rays is considered in this paper, and examples are presented of the use of the diffuse scattering to study the defects. X-ray studies of self-interstitials in electron irradiated aluminum and copper are discussed in terms of the identification of the interstitial configuration. Methods for detecting the onset of point defect aggregation into dislocation loops are considered and new techniques for the determination of separate size distributions for vacancy loops and interstitial loops are presented. Direct comparisons of dislocation loop measurements by x-rays with existing electron microscopy studies of dislocation loops indicate agreement for larger size loops, but x-ray measurements report higher concentrations in the smaller loop range. Methods for distinguishing between loops and three-dimensional precipitates are discussed and possibilities for detailed studies considered. A comparison of dislocation loop size distributions obtained from integral diffuse scattering measurements with those from TEM show a discrepancy in the smaller sizes similar to that described above.

  6. The roles of RIIbeta linker and N-terminal cyclic nucleotide-binding domain in determining the unique structures of Type IIbeta Protein Kinase A. A small angle X-ray and neutron scattering study

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Blumenthal, Donald K.; Copps, Jeffrey; Smith-Nguyen, Eric V.; Zhang, Ping; Heller, William T.; Taylor, Susan S.

    2014-08-11

    Protein kinase A (PKA) is ubiquitously expressed and is responsible for regulating many important cellular functions in response to changes in intracellular cAMP concentrations. Moreover, the PKA holoenzyme is a tetramer (R2:C2), with a regulatory subunit homodimer (R2) that binds and inhibits two catalytic (C) subunits; binding of cAMP to the regulatory subunit homodimer causes activation of the catalytic subunits. Four different R subunit isoforms exist in mammalian cells, and these confer different structural features, subcellular localization, and biochemical properties upon the PKA holoenzymes they form. The holoenzyme containing RIIβ is structurally unique in that the type IIβ holoenzyme ismore » much more compact than the free RIIβ homodimer. We have used small angle x-ray scattering and small angle neutron scattering to study the solution structure and subunit organization of a holoenzyme containing an RIIβ C-terminal deletion mutant (RIIβ(1–280)), which is missing the C-terminal cAMP-binding domain to better understand the structural organization of the type IIβ holoenzyme and the RIIβ domains that contribute to stabilizing the holoenzyme conformation. These results demonstrate that compaction of the type IIβ holoenzyme does not require the C-terminal cAMP-binding domain but rather involves large structural rearrangements within the linker and N-terminal cyclic nucleotide-binding domain of the RIIβ homodimer. The structural rearrangements are significantly greater than seen previously with RIIα and are likely to be important in mediating short range and long range interdomain and intersubunit interactions that uniquely regulate the activity of the type IIβ isoform of PKA.« less

  7. X-ray and Neutron Scattering Study of the Formation of Core–Shell-Type Polyoxometalates

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Yin, Panchao; Wu, Bin; Mamontov, Eugene; Daemen, Luke L.; Cheng, Yongqiang; Li, Tao; Seifert, Soenke; Hong, Kunlun; Bonnesen, Peter V.; Keum, Jong Kahk; et al

    2016-02-05

    A typical type of core-shell polyoxometalates can be obtained through the Keggin-type polyoxometalate-templated growth of a layer of spherical shell structure of {Mo72Fe30}. Small angle X-ray scattering is used to study the structural features and stability of the core-shell structures in aqueous solutions. Time-resolved small angle X-ray scattering is applied to monitor the synthetic reactions and a three-stage formation mechanism is proposed to describe the synthesis of the core-shell polyoxometalates based on the monitoring results. Quasi-elastic and inelastic neutron scattering are used to probe the dynamics of water molecules in the core-shell structures and two different types of water molecules,more » the confined and structured water, are observed. These water molecules play an important role in bridging core and shell structures and stabilizing the cluster structures. A typical type of core shell polyoxometalates can be obtained through the Keggin-type polyoxometalate-templated growth of a layer of spherical shell structure of {Mo72Fe30}. Small-angle X-ray scattering is used to study the structural features and stability of the core shell structures in aqueous solutions. Time-resolved small-angle X-ray scattering is applied to monitor the synthetic reactions, and a three-stage formation mechanism is proposed to describe the synthesis of the core shell polyoxometalates based on the monitoring results. New protocols have been developed by fitting the X-ray data with custom physical models, which provide more convincing, objective, and completed data interpretation. Quasi-elastic and inelastic neutron scattering are used to probe the dynamics of water molecules in the core shell structures, and two different types of water molecules, the confined and structured water, are observed. These water molecules play an important role in bridging core and shell structures and stabilizing the cluster structures.« less

  8. X-ray and Neutron Scattering Study of the Formation of Core-Shell Type Polyoxometalates

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Yin, Panchao; Wu, Bin; Mamontov, Eugene; Daemen, Luke L; Cheng, Yongqiang; Hong, Kunlun; Bonnesen, Peter V; Keum, Jong Kahk; Ramirez-Cuesta, Anibal J

    2016-01-01

    A typical type of core-shell polyoxometalates can be obtained through the Keggin-type polyoxometalate-templated growth of a layer of spherical shell structure of {Mo72Fe30}. Small angle X-ray scattering is used to study the structural features and stability of the core-shell structures in aqueous solutions. Time-resolved small angle X-ray scattering is applied to monitor the synthetic reactions and a three-stage formation mechanism is proposed to describe the synthesis of the core-shell polyoxometalates based on the monitoring results. Quasi-elastic and inelastic neutron scattering are used to probe the dynamics of water molecules in the core-shell structures and two different types of water molecules,morethe confined and structured water, are observed. These water molecules play an important role in bridging core and shell structures and stabilizing the cluster structures.A typical type of core shell polyoxometalates can be obtained through the Keggin-type polyoxometalate-templated growth of a layer of spherical shell structure of {Mo72Fe30}. Small-angle X-ray scattering is used to study the structural features and stability of the core shell structures in aqueous solutions. Time-resolved small-angle X-ray scattering is applied to monitor the synthetic reactions, and a three-stage formation mechanism is proposed to describe the synthesis of the core shell polyoxometalates based on the monitoring results. New protocols have been developed by fitting the X-ray data with custom physical models, which provide more convincing, objective, and completed data interpretation. Quasi-elastic and inelastic neutron scattering are used to probe the dynamics of water molecules in the core shell structures, and two different types of water molecules, the confined and structured water, are observed. These water molecules play an important role in bridging core and shell structures and stabilizing the cluster structures.less

  9. Structural dynamics and ssDNA binding activity of the three N-terminal domains of the large subunit of Replication Protein A from small angle X-ray scattering

    SciTech Connect (OSTI)

    Pretto, Dalyir I.; Tsutakawa, Susan; Brosey, Chris A.; Castillo, Amalchi; Chagot, Marie-Eve; Smith, Jarrod A.; Tainer, John A.; Chazin, Walter J.

    2010-03-11

    Replication Protein A (RPA) is the primary eukaryotic ssDNA binding protein utilized in diverse DNA transactions in the cell. RPA is a heterotrimeric protein with seven globular domains connected by flexible linkers, which enable substantial inter-domain motion that is essential to its function. Small angle X-ray scattering (SAXS) experiments on two multi-domain constructs from the N-terminus of the large subunit (RPA70) were used to examine the structural dynamics of these domains and their response to the binding of ssDNA. The SAXS data combined with molecular dynamics simulations reveal substantial interdomain flexibility for both RPA70AB (the tandem high affinity ssDNA binding domains A and B connected by a 10-residue linker) and RPA70NAB (RPA70AB extended by a 70-residue linker to the RPA70N protein interaction domain). Binding of ssDNA to RPA70NAB reduces the interdomain flexibility between the A and B domains, but has no effect on RPA70N. These studies provide the first direct measurements of changes in orientation of these three RPA domains upon binding ssDNA. The results support a model in which RPA70N remains structurally independent of RPA70AB in the DNA bound state and therefore freely available to serve as a protein recruitment module.

  10. X-ray Thomson Scattering from Dense Plasmas

    SciTech Connect (OSTI)

    Glenzer, S

    2007-05-14

    Advances in the development of laser-produced x-ray sources have enabled a new class of high-energy density physics experiments. Powerful narrow-bandwidth x rays penetrate through short-lived hot dense states of matter and probe the physical properties with spectrally resolved x-ray scattering. Experiments from isochorically-heated plasmas with electron densities in the range of solid density and above have been demonstrated allowing for the first time exploration of the microscopic properties of dense matter regime close to strongly-coupled and Fermi degenerate conditions. Backscatter measurements have accessed the non-collective Compton scattering regime, which provides accurate diagnostic information on the temperature, density and ionization states. The forward scattering spectrum has been shown to measure the collective plasmon oscillations. Besides extracting the standard plasma parameters, density and temperature, forward scattering yields new observables such as a direct measure of collisions, quantum effects and detailed balance. In this talk, we will discuss new results important for applications of this technique for novel experiments in a wide range of research areas such as inertial confinement fusion, radiation-hydrodynamics, material science, and laboratory astrophysics.

  11. Inelastic X-ray Scattering from Shocked Liquid Deuterium

    SciTech Connect (OSTI)

    Regan, S. P.; Falk, K.; Gregori, G.; Radha, P. B.; Hu, S. X.; Boehly, T. R.; Crowley, B.; Glenzer, S. H.; Landen, O.; Gericke, D. O.; Doeppner, T.; Meyerhofer, D. D.; Murphy, C. D.; Sangster, T. C.; Vorberger, J.

    2012-12-28

    The Fermi-degenerate plasma conditions created in liquid deuterium by a laser-ablation—driven shock wave were probed with noncollective, spectrally resolved, inelastic x-ray Thomson scattering employing Cl Lyα line emission at 2.96 keV. Thus, these first x-ray Thomson scattering measurements of the microscopic properties of shocked deuterium show an inferred spatially averaged electron temperature of 8±5 eV, an electron density of 2.2(±0.5)×1023 cm-3, and an ionization of 0.8 (-0.25, +0.15). Our two-dimensional hydrodynamic simulations using equation-of-state models suited for the extreme parameters occurring in inertial confinement fusion research and planetary interiors are consistent with the experimental results.

  12. Inelastic X-ray Scattering from Shocked Liquid Deuterium

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Regan, S. P.; Falk, K.; Gregori, G.; Radha, P. B.; Hu, S. X.; Boehly, T. R.; Crowley, B.; Glenzer, S. H.; Landen, O.; Gericke, D. O.; et al

    2012-12-28

    The Fermi-degenerate plasma conditions created in liquid deuterium by a laser-ablation—driven shock wave were probed with noncollective, spectrally resolved, inelastic x-ray Thomson scattering employing Cl Lyα line emission at 2.96 keV. Thus, these first x-ray Thomson scattering measurements of the microscopic properties of shocked deuterium show an inferred spatially averaged electron temperature of 8±5 eV, an electron density of 2.2(±0.5)×1023 cm-3, and an ionization of 0.8 (-0.25, +0.15). Our two-dimensional hydrodynamic simulations using equation-of-state models suited for the extreme parameters occurring in inertial confinement fusion research and planetary interiors are consistent with the experimental results.

  13. SMB, Small Angle X-Ray Scattering

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    ligula metus convallis tellus, sit amet consequat ante neque iaculis augue. Cras ut erat id diam aliquam volutpat quis ac tellus. Ut eget vulputate sem, nec lobortis...

  14. Combining THz laser excitation with resonant soft X-ray scattering...

    Office of Scientific and Technical Information (OSTI)

    resonant soft X-ray scattering at the Linac Coherent Light Source Citation Details In-Document Search Title: Combining THz laser excitation with resonant soft X-ray scattering ...

  15. Linear Dichroism in Resonant Inelastic X-Ray Scattering to Molecular...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Linear Dichroism in Resonant Inelastic X-Ray Scattering to Molecular Spin-Orbit States Linear Dichroism in Resonant Inelastic X-Ray Scattering to Molecular Spin-Orbit States Print...

  16. In Situ X-Ray Scattering Helps Optimize Printed Solar Cells

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    In Situ X-Ray Scattering Helps Optimize Printed Solar Cells In Situ X-Ray Scattering Helps Optimize Printed Solar Cells Print Wednesday, 25 February 2015 00:00 Plastic solar cells...

  17. Resonant Soft X-Ray Scattering of Tri-Block Copolymers

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Resonant Soft X-Ray Scattering of Tri-Block Copolymers Resonant Soft X-Ray Scattering of Tri-Block Copolymers Print Wednesday, 30 May 2012 00:00 In principle, tri-block copolymers...

  18. Resonant Soft X-Ray Scattering of Tri-Block Copolymers

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Resonant Soft X-Ray Scattering of Tri-Block Copolymers Print In principle, tri-block ... has succeeded in combining resonant soft x-ray scattering (RSoXS) at ALS Beamline 11.0.1 ...

  19. SSRL School 2007 on Hard X-ray Scattering Techniques in MES

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    May 15-17, 2007 SSRL School on Hard X-ray Scattering Techniques in Materials and Environmental Sciences Group photo taken at the SSRL School on Hard X-ray Scattering Techniques in...

  20. Predictions of x-ray scattering spectra in warm dense matter...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Technical Report: Predictions of x-ray scattering spectra in warm dense matter Citation Details In-Document Search Title: Predictions of x-ray scattering spectra in warm dense ...

  1. X-ray and neutron scattering from nano-mgantic clusters | The...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    X-ray and neutron scattering from nano-mgantic clusters The student will participate in hands on X-ray scattering experiments on bio-inspired inorganic materials (i.e., magnetic...

  2. IN SITU SURFACE X-RAY SCATTERING STUDIES OF ELECTROSORPTION

    SciTech Connect (OSTI)

    WANG,J.X.; ADZIC,R.R.; OCKO,B.M.

    1998-07-01

    A short review of the application of surface x-ray scattering techniques to the electrode/electrolyte interfaces is presented. Recent results on metal, halide, and metal-halide adlayers with three specific systems: Bi on Au(100) and Au(110); Br on Au(100) and Ag(100); and the coadsorption of Tl with Br or I on Au(111), are given as an illustration. Factors affecting ordering of pure metal and halide adlayers and the metal-halide surface compounds are discussed in some detail.

  3. In situ small angle x-ray studies of coal gasification

    SciTech Connect (OSTI)

    Jensen, K F

    1983-01-01

    This report summarizes the progress made the first 12 months of a planned 36 month project on small angle x-ray studies of coal and char pore structure. Model carbon studies have been employed to demonstrate the usefulness of small angle x-ray scattering (SAXS) in monitoring the structural changes in porous carbonaceous materials during gasification. Scattering data from particles gasified to varying levels of conversion show increases in the micropore sizes with conversion. This is also supported by surface area measurements by SAXS showing a maximum at intermediate conversion in agreements with previous studies by conventional means. The application of SAXS to PSOC coal samples is also demonstrated. Existing models for the porous structure have been reviewed and percolation theory has been selected as a consistent framework for both the modelling and the data analysis. This theory will make it possible to describe the porous structure in terms of its geometry and connectivity, rather than being limited to a fixed geometry as in conventional approaches. Two graduate students and the PI have been trained in SAXS and the associated theory. Results from the model carbon studies have been published. 18 references, 9 figures, 2 tables.

  4. Air-core grid for scattered x-ray rejection

    DOE Patents [OSTI]

    Logan, Clinton M.; Lane, Stephen M.

    1995-01-01

    The invention is directed to a grid used in x-ray imaging applications to block scattered radiation while allowing the desired imaging radiation to pass through, and to process for making the grid. The grid is composed of glass containing lead oxide, and eliminates the spacer material used in prior known grids, and is therefore, an air-core grid. The glass is arranged in a pattern so that a large fraction of the area is open allowing the imaging radiation to pass through. A small pore size is used and the grid has a thickness chosen to provide high scatter rejection. For example, the grid may be produced with a 200 .mu.m pore size, 80% open area, and 4 mm thickness.

  5. Air-core grid for scattered x-ray rejection

    DOE Patents [OSTI]

    Logan, C.M.; Lane, S.M.

    1995-10-03

    The invention is directed to a grid used in x-ray imaging applications to block scattered radiation while allowing the desired imaging radiation to pass through, and to process for making the grid. The grid is composed of glass containing lead oxide, and eliminates the spacer material used in prior known grids, and is therefore, an air-core grid. The glass is arranged in a pattern so that a large fraction of the area is open allowing the imaging radiation to pass through. A small pore size is used and the grid has a thickness chosen to provide high scatter rejection. For example, the grid may be produced with a 200 {micro}m pore size, 80% open area, and 4 mm thickness. 2 figs.

  6. Large-scale Nanostructure Simulations from X-ray Scattering Data On Graphics Processor Clusters

    SciTech Connect (OSTI)

    Sarje, Abhinav; Pien, Jack; Li, Xiaoye; Chan, Elaine; Chourou, Slim; Hexemer, Alexander; Scholz, Arthur; Kramer, Edward

    2012-01-15

    X-ray scattering is a valuable tool for measuring the structural properties of materialsused in the design and fabrication of energy-relevant nanodevices (e.g., photovoltaic, energy storage, battery, fuel, and carbon capture andsequestration devices) that are key to the reduction of carbon emissions. Although today's ultra-fast X-ray scattering detectors can provide tremendousinformation on the structural properties of materials, a primary challenge remains in the analyses of the resulting data. We are developing novelhigh-performance computing algorithms, codes, and software tools for the analyses of X-ray scattering data. In this paper we describe two such HPCalgorithm advances. Firstly, we have implemented a flexible and highly efficient Grazing Incidence Small Angle Scattering (GISAXS) simulation code based on theDistorted Wave Born Approximation (DWBA) theory with C++/CUDA/MPI on a cluster of GPUs. Our code can compute the scattered light intensity from any givensample in all directions of space; thus allowing full construction of the GISAXS pattern. Preliminary tests on a single GPU show speedups over 125x compared tothe sequential code, and almost linear speedup when executing across a GPU cluster with 42 nodes, resulting in an additional 40x speedup compared to usingone GPU node. Secondly, for the structural fitting problems in inverse modeling, we have implemented a Reverse Monte Carlo simulation algorithm with C++/CUDAusing one GPU. Since there are large numbers of parameters for fitting in the in X-ray scattering simulation model, the earlier single CPU code required weeks ofruntime. Deploying the AccelerEyes Jacket/Matlab wrapper to use GPU gave around 100x speedup over the pure CPU code. Our further C++/CUDA optimization deliveredan additional 9x speedup.

  7. Evolution of Elastic X-ray Scattering in Laser-Shocked Warm Dense Li

    SciTech Connect (OSTI)

    Kugland, N L; Gregori, G; Bandyopadhyay, S; Brenner, C; Brown, C; Constantin, C; Glenzer, S H; Khattak, F; Kritcher, A L; Niemann, C; Otten, A; Pasley, J; Pelka, A; Roth, M; Spindloe, C; Riley, D

    2009-06-02

    We have studied the dynamics of warm dense Li with near-elastic x-ray scattering. Li foils were heated and compressed using shock waves driven by 4 ns long laser pulses. Separate 1 ns long laser pulses were used to generate a bright source of 2.96 keV Cl Ly-{alpha} photons for x-ray scattering, and the spectrum of scattered photons was recorded at a scattering angle of 120{sup o} using a HOPG crystal operated in the von Hamos geometry. A variable delay between the heater and backlighter laser beams measured the scattering time evolution. Comparison with radiation hydrodynamics simulations shows that the plasma is highly coupled during the first several nanoseconds, then relaxes to a moderate coupling state at later times. Near-elastic scattering amplitudes have been successfully simulated using the screened one-component plasma model. Our main finding is that the near-elastic scattering amplitudes are quite sensitive to the mean ionization state {bar Z}, and by extension to the choice of ionization model in the radiation-hydrodynamics simulations used to predict plasma properties within the shocked Li.

  8. White dwarfs as the maximal soft x-ray scatterers

    SciTech Connect (OSTI)

    Akbari-Moghanjoughi, M.; International Centre for Advanced Studies in Physical Sciences and Institute for Theoretical Physics, Ruhr University Bochum, D-44780 Bochum

    2013-09-15

    In this paper, we explore the effect of density on the structure formation and the electromagnetic wave (EMw) elastic scattering on quantum plasmas, using the generalized quantum hydrodynamic model valid for a wide range of the plasma density and relativistic degeneracy. It is found that the electron quantum diffraction effect caused by the Bohm potential has a fundamental effect on the ion correlations in a degenerate electron fluid and crystallization in quantum plasmas in the solid-density regime and beyond. The ion correlations and structure formation are shown to be fundamentally affected by the plasma density and the relativistic degeneracy parameters. Moreover, distinct behavior is shown to exist between the non-relativistic and relativistic matter density regimes, regarding the normalized EMw elastic scattering cross-sections. It is theoretically discovered that the maximal Thomson scattering coincides with the average density of a typical white dwarf corresponding to the soft X-ray wavelength regime. Current research can be very useful in plasma optical diagnostic methods for a wide range of electron number-density from warm dense matter and inertial confinement fusion to the astrophysical compact objects.

  9. OSTIblog Articles in the x-ray scattering Topic | OSTI, US Dept...

    Office of Scientific and Technical Information (OSTI)

    X-ray scattering has been used to gather clues about materials' atomic structures for about a century. Once reactors were built that could provide intense neutron beams, ...

  10. 6th Annual SSRL School on Synchrotron X-ray Scattering, May 29...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Transportation About 6th Annual SSRL School on Synchrotron X-ray Scattering Techniques in Materials and Environmental Sciences: Theory and Application May 29-31 2012...

  11. Spectral softening in the X-RAY afterglow of GRB 130925A as predicted by the dust scattering model

    SciTech Connect (OSTI)

    Zhao, Yi-Nan; Shao, Lang, E-mail: lshao@hebtu.edu.cn [Department of Space Science and Astronomy, Hebei Normal University, Shijiazhuang 050024 (China)

    2014-07-01

    Gamma-ray bursts (GRBs) usually occur in a dense star-forming region with a massive circumburst medium. The small-angle scattering of intense prompt X-ray emission off the surrounding dust grains will have observable consequences and sometimes can dominate the X-ray afterglow. In most of the previous studies, only the Rayleigh-Gans (RG) approximation is employed for describing the scattering process, which works accurately for the typical size of grains (with radius of a ? 0.1 ?m) in the diffuse interstellar medium. When the size of the grains may significantly increase, as in a more dense region where GRBs would occur, the RG approximation may not be valid enough for modeling detailed observational data. In order to study the temporal and spectral properties of the scattered X-ray emission more accurately with potentially larger dust grains, we provide a practical approach using the series expansions of anomalous diffraction (AD) approximation based on the complicated Mie theory. We apply our calculations to understand the puzzling X-ray afterglow of recently observed GRB 130925A that showed a significant spectral softening. We find that the X-ray scattering scenarios with either AD or RG approximation adopted could well reproduce both the temporal and spectral profile simultaneously. Given the plateau present in the early X-ray light curve, a typical distribution of smaller grains as in the interstellar medium would be suggested for GRB 130925A.

  12. K-alpha conversion efficiency measurments for x-ray scattering in inertial confinement fusion plasmas

    SciTech Connect (OSTI)

    Kritcher, A L; Neumayer, P; Urry, M K; Robey, H; Niemann, C; Landen, O L; Morse, E; Glenzer, S H

    2006-11-21

    The conversion efficiency of ultra short-pulse laser radiation to K-{alpha} x-rays has been measured for various chlorine-containing targets to be used as x-ray scattering probes of dense plasmas. The spectral and temporal properties of these sources will allow spectrally-resolved x-ray scattering probing with picosecond temporal resolution required for measuring the plasma conditions in inertial confinement fusion experiments. Simulations of x-ray scattering spectra from these plasmas show that fuel capsule density, capsule ablator density, and shock timing information may be inferred.

  13. Transmission X-ray scattering as a probe for complex liquid-surface structures

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Fukuto, Masafumi; Yang, Lin; Nykypanchuk, Dmytro; Kuzmenko, Ivan

    2016-01-28

    The need for functional materials calls for increasing complexity in self-assembly systems. As a result, the ability to probe both local structure and heterogeneities, such as phase-coexistence and domain morphologies, has become increasingly important to controlling self-assembly processes, including those at liquid surfaces. The traditional X-ray scattering methods for liquid surfaces, such as specular reflectivity and grazing-incidence diffraction, are not well suited to spatially resolving lateral heterogeneities due to large illuminated footprint. A possible alternative approach is to use scanning transmission X-ray scattering to simultaneously probe local intermolecular structures and heterogeneous domain morphologies on liquid surfaces. To test the feasibilitymore » of this approach, transmission small- and wide-angle X-ray scattering (TSAXS/TWAXS) studies of Langmuir films formed on water meniscus against a vertically immersed hydrophilic Si substrate were recently carried out. First-order diffraction rings were observed in TSAXS patterns from a monolayer of hexagonally packed gold nanoparticles and in TWAXS patterns from a monolayer of fluorinated fatty acids, both as a Langmuir monolayer on water meniscus and as a Langmuir–Blodgett monolayer on the substrate. The patterns taken at multiple spots have been analyzed to extract the shape of the meniscus surface and the ordered-monolayer coverage as a function of spot position. These results, together with continual improvement in the brightness and spot size of X-ray beams available at synchrotron facilities, support the possibility of using scanning-probe TSAXS/TWAXS to characterize heterogeneous structures at liquid surfaces.« less

  14. A semianalytic model to extract differential linear scattering coefficients of breast tissue from energy dispersive x-ray diffraction measurements

    SciTech Connect (OSTI)

    LeClair, Robert J.; Boileau, Michel M.; Wang Yinkun [Department of Physics and Astronomy, Laurentian University, 935 Ramsey Lake Road, Sudbury, Ontario, P3E 2C6 (Canada) and Biomolecular Sciences Program, Laurentian University, 935 Ramsey Lake Road, Sudbury, Ontario, P3E 2C6 (Canada); Department of Physics and Astronomy, Laurentian University, 935 Ramsey Lake Road, Sudbury, Ontario, P3E 2C6 (Canada); Department of Physics and Astronomy, Laurentian University, 935 Ramsey Lake Road, Sudbury, Ontario, P3E 2C6 (Canada)

    2006-04-15

    The goal of this work is to develop a technique to measure the x-ray diffraction signals of breast biopsy specimens. A biomedical x-ray diffraction technology capable of measuring such signals may prove to be of diagnostic use to the medical field. Energy dispersive x-ray diffraction measurements coupled with a semianalytical model were used to extract the differential linear scattering coefficients [{mu}{sub s}(x)] of breast tissues on absolute scales. The coefficients describe the probabilities of scatter events occurring per unit length of tissue per unit solid angle of detection. They are a function of the momentum transfer argument, x=sin({theta}/2)/{lambda}, where {theta}=scatter angle and {lambda}=incident wavelength. The technique was validated by using a 3 mm diameter 50 kV polychromatic x-ray beam incident on a 5 mm diameter 5 mm thick sample of water. Water was used because good x-ray diffraction data are available in the literature. The scatter profiles from 6 deg. to 15 deg. in increments of 1 deg. were measured with a 3 mmx3 mmx2 mm thick cadmium zinc telluride detector. A 2 mm diameter Pb aperture was placed on top of the detector. The target to detector distance was 29 cm and the duration of each measurement was 10 min. Ensemble averages of the results compare well with the gold standard data of A. H. Narten [''X-ray diffraction data on liquid water in the temperature range 4 deg. C-200 deg. C, ORNL Report No. 4578 (1970)]. An average 7.68% difference for which most of the discrepancies can be attributed to the background noise at low angles was obtained. The preliminary measurements of breast tissue are also encouraging.

  15. Azimuthal anisotropy of the scattered radiation in grazing incidence X-ray fluorescence

    SciTech Connect (OSTI)

    Das, Gangadhar Tiwari, M. K.; Singh, A. K.; Ghosh, Haranath

    2015-06-24

    The Compton and elastic scattering radiations are the major contributor to the spectral background of an x-ray fluorescence spectrum, which eventually limits the element detection sensitivities of the technique to µg/g (ppm) range. In the present work, we provide a detail mathematical descriptions and show that how polarization properties of the synchrotron radiation influence the spectral background in the x-ray fluorescence technique. We demonstrate our theoretical understandings through experimental observations using total x-ray fluorescence measurements on standard reference materials. Interestingly, the azimuthal anisotropy of the scattered radiation is shown to have a vital role on the significance of the x-ray fluorescence detection sensitivities.

  16. Resonant Soft X-Ray Scattering - Combining Structural with Spectroscop...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    28, 2012 - 10:00am SLAC, Bldg. 137, Room 322 SSRL Presents Kevin Stone X-ray absorption spectroscopy has become an important tool in understanding the electronic structure...

  17. Probing Spatial, Electronic Structures with X-ray Scattering...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Wednesday, September 5, 2012 - 10:45am SLAC, Bldg. 137, Room 226 Gang Chen Seminar: Structures at atomic scales are traditionally determined through X-ray crystallography that ...

  18. Protein folding and protein metallocluster studies using synchrotron small angler X-ray scattering

    SciTech Connect (OSTI)

    Eliezer, D.

    1994-06-01

    Proteins, biological macromolecules composed of amino-acid building blocks, possess unique three dimensional shapes or conformations which are intimately related to their biological function. All of the information necessary to determine this conformation is stored in a protein`s amino acid sequence. The problem of understanding the process by which nature maps protein amino-acid sequences to three-dimensional conformations is known as the protein folding problem, and is one of the central unsolved problems in biophysics today. The possible applications of a solution are broad, ranging from the elucidation of thousands of protein structures to the rational modification and design of protein-based drugs. The scattering of X-rays by matter has long been useful as a tool for the characterization of physical properties of materials, including biological samples. The high photon flux available at synchrotron X-ray sources allows for the measurement of scattering cross-sections of dilute and/or disordered samples. Such measurements do not yield the detailed geometrical information available from crystalline samples, but do allow for lower resolution studies of dynamical processes not observable in the crystalline state. The main focus of the work described here has been the study of the protein folding process using time-resolved small-angle x-ray scattering measurements. The original intention was to observe the decrease in overall size which must accompany the folding of a protein from an extended conformation to its compact native state. Although this process proved too fast for the current time-resolution of the technique, upper bounds were set on the probable compaction times of several small proteins. In addition, an interesting and unexpected process was detected, in which the folding protein passes through an intermediate state which shows a tendency to associate. This state is proposed to be a kinetic molten globule folding intermediate.

  19. XRS 2016 - 8th SSRL School on Synchrotron X-Ray Scattering Techniques

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    XRS 2016 - 8th SSRL School on Synchrotron X-Ray Scattering Techniques Home Registration Location Visitor Information Transportation About XRS 2016 - 8th SSRL School on Synchrotron X-Ray Scattering Techniques Materials and Environmental Sciences: Theory and Application June 21-23 2016 BL2-1 Feedback Form Agenda 2016 Agenda Maps & Directions Visiting SLAC This school will provide a practical users' guide to planning and conducting scattering measurements at SSRL beam lines, and will cover

  20. Resonant elastic soft x-ray scattering in oxygen-ordered YBa2Cu3O6...

    Office of Scientific and Technical Information (OSTI)

    Resonant elastic soft x-ray scattering in oxygen-ordered YBa2Cu3O6+ Citation Details In-Document Search Title: Resonant elastic soft x-ray scattering in oxygen-ordered...

  1. 16th National School on Neutron and X-ray Scattering

    SciTech Connect (OSTI)

    Chakoumakos, Bryan; Achilles, Cherie; Cybulskis, Viktor; Gilbert, Ian

    2014-07-02

    Students talk about their experience at the 16th National School on Neutron and X-ray Scattering, or NXS 2014. Jointly conducted by Oak Ridge and Argonne national laboratories, NXS immerses graduate students in national user facilities to learn in a hands-on environment how to use neutrons and X-rays in their research.

  2. 16th National School on Neutron and X-ray Scattering

    ScienceCinema (OSTI)

    Chakoumakos, Bryan; Achilles, Cherie; Cybulskis, Viktor; Gilbert, Ian

    2014-07-23

    Students talk about their experience at the 16th National School on Neutron and X-ray Scattering, or NXS 2014. Jointly conducted by Oak Ridge and Argonne national laboratories, NXS immerses graduate students in national user facilities to learn in a hands-on environment how to use neutrons and X-rays in their research.

  3. Acquisition of an In-House X-ray Scattering Facility for Nanostructure Characterization and Student Training

    SciTech Connect (OSTI)

    Schuller, Ivan K [UC San Diego

    2013-08-02

    This equipment grant was specifically dedicated to the development of a "state of the art" x-ray scattering facility...

  4. Wide-angle point-to-point x-ray imaging with almost arbitrarily large angles of incidence

    SciTech Connect (OSTI)

    Bitter, M.; Hill, K. W.; Scott, S.; Feder, R.; Ko, Jinseok; Ince-Cushman, A.; Rice, J. E.

    2008-10-15

    The paper describes a new scheme for wide-angle point-to-point x-ray imaging with almost arbitrarily large angles of incidence by a matched pair of spherically bent crystals to eliminate the astigmatism, which is a well-known imaging error of spherical mirrors. In addition to x rays, the scheme should be applicable to a very broad spectrum of the electromagnetic radiation, including microwaves, infrared and visible light, as well as UV and extreme UV radiation, if the crystals are replaced with appropriate spherical reflectors. The scheme may also be applicable to the imaging with ultrasound.

  5. Reflection thermal diffuse x-ray scattering for quantitative determination of phonon dispersion relations

    SciTech Connect (OSTI)

    Mei, A. B.; Hellman, O.; Schlepuetz, C. M.; Rockett, A.; Chiang, T. -C.; Hultman, L.; Petrov, I.; Greene, J. E.

    2015-11-03

    Synchrotron reflection x-ray thermal diffuse scattering (TDS) measurements, rather than previously reported transmission TDS, are carried out at room temperature and analyzed using a formalism based upon second-order interatomic force constants and long-range Coulomb interactions to obtain quantitative determinations of MgO phonon dispersion relations (h) over bar omega(j) (q), phonon densities of states g((h) over bar omega), and isochoric temperature-dependent vibrational heat capacities cv (T). We use MgO as a model system for investigating reflection TDS due to its harmonic behavior as well as its mechanical and dynamic stability. Resulting phonon dispersion relations and densities of states are found to be in good agreement with independent reports from inelastic neutron and x-ray scattering experiments. Temperature-dependent isochoric heat capacities cv (T), computed within the harmonic approximation from (h) over bar omega(j) (q) values, increase with temperature from 0.4 x 10-4 eV/atom K at 100 K to 1.4 x 10-4 eV/atom K at 200 K and 1.9 x 10-4 eV/atom K at 300 K, in excellent agreement with isobaric heat capacity values cp (T) between 4 and 300 K. We anticipate that the experimental approach developed here will be valuable for determining vibrational properties of heteroepitaxial thin films since the use of grazing-incidence (θ ≲ θc where θc is the density-dependent critical angle) allows selective tuning of x-ray penetration depths to ≲ 10 nm.

  6. Reflection thermal diffuse x-ray scattering for quantitative determination of phonon dispersion relations

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Mei, A. B.; Hellman, O.; Schlepuetz, C. M.; Rockett, A.; Chiang, T. -C.; Hultman, L.; Petrov, I.; Greene, J. E.

    2015-11-03

    Synchrotron reflection x-ray thermal diffuse scattering (TDS) measurements, rather than previously reported transmission TDS, are carried out at room temperature and analyzed using a formalism based upon second-order interatomic force constants and long-range Coulomb interactions to obtain quantitative determinations of MgO phonon dispersion relations (h) over bar omega(j) (q), phonon densities of states g((h) over bar omega), and isochoric temperature-dependent vibrational heat capacities cv (T). We use MgO as a model system for investigating reflection TDS due to its harmonic behavior as well as its mechanical and dynamic stability. Resulting phonon dispersion relations and densities of states are found tomore » be in good agreement with independent reports from inelastic neutron and x-ray scattering experiments. Temperature-dependent isochoric heat capacities cv (T), computed within the harmonic approximation from (h) over bar omega(j) (q) values, increase with temperature from 0.4 x 10-4 eV/atom K at 100 K to 1.4 x 10-4 eV/atom K at 200 K and 1.9 x 10-4 eV/atom K at 300 K, in excellent agreement with isobaric heat capacity values cp (T) between 4 and 300 K. We anticipate that the experimental approach developed here will be valuable for determining vibrational properties of heteroepitaxial thin films since the use of grazing-incidence (θ ≲ θc where θc is the density-dependent critical angle) allows selective tuning of x-ray penetration depths to ≲ 10 nm.« less

  7. Resonant Soft X-Ray Scattering of Tri-Block Copolymers

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Resonant Soft X-Ray Scattering of Tri-Block Copolymers Print In principle, tri-block copolymers (tri-BCPs), consisting of three chemically distinct polymers covalently joined...

  8. An X-ray and Neutron Scattering Study of the Formation of Core...

    Office of Scientific and Technical Information (OSTI)

    of the Formation of Core-Shell Type Polyoxometalates Citation Details In-Document Search Title: An X-ray and Neutron Scattering Study of the Formation of Core-Shell Type ...

  9. X Ray Scattering | U.S. DOE Office of Science (SC)

    Office of Science (SC) Website

    Research Areas X Ray Scattering Print Text Size: A A A FeedbackShare Page This activity ... matter to achieve an understanding of atomic, electronic, and magnetic structures and ...

  10. 5th Annual SSRL School on Synchrotron X-ray Scattering Techniques...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Web | People Search SSRL Go 5th Annual SSRL School on Synchrotron X-ray Scattering Techniques in Materials and Environmental Sciences: Theory and Application June 1-3, 2010...

  11. The 3D-architecture of individual free silver nanoparticles captured by X-ray scattering

    SciTech Connect (OSTI)

    Barke, Ingo; Hartmann, Hannes; Rupp, Daniela; Flückiger, Leonie; Sauppe, Mario; Adolph, Marcus; Schorb, Sebastian; Bostedt, Christoph; Treusch, Rolf; Peltz, Christian; Bartling, Stephan; Fennel, Thomas; Meiwes-Broer, Karl-Heinz; Möller, Thomas

    2015-02-04

    The diversity of nanoparticle shapes generated by condensation from gaseous matter reflects the fundamental competition between thermodynamic equilibration and the persistence of metastable configurations during growth. In the kinetically limited regime, intermediate geometries that are favoured only in early formation stages can be imprinted in the finally observed ensemble of differently structured specimens. Here we demonstrate that single-shot wide-angle scattering of femtosecond soft X-ray free-electron laser pulses allows three-dimensional characterization of the resulting metastable nanoparticle structures. For individual free silver particles, which can be considered frozen in space for the duration of photon exposure, both shape and orientation are uncovered from measured scattering images. We identify regular shapes, including species with fivefold symmetry and surprisingly large aspect ratio up to particle radii of the order of 100 nm. Our approach includes scattering effects beyond Born’s approximation and is remarkably efficient—opening up new routes in ultrafast nanophysics and free-electron laser science

  12. The 3D-architecture of individual free silver nanoparticles captured by X-ray scattering

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Barke, Ingo; Hartmann, Hannes; Rupp, Daniela; Flückiger, Leonie; Sauppe, Mario; Adolph, Marcus; Schorb, Sebastian; Bostedt, Christoph; Treusch, Rolf; Peltz, Christian; et al

    2015-02-04

    The diversity of nanoparticle shapes generated by condensation from gaseous matter reflects the fundamental competition between thermodynamic equilibration and the persistence of metastable configurations during growth. In the kinetically limited regime, intermediate geometries that are favoured only in early formation stages can be imprinted in the finally observed ensemble of differently structured specimens. Here we demonstrate that single-shot wide-angle scattering of femtosecond soft X-ray free-electron laser pulses allows three-dimensional characterization of the resulting metastable nanoparticle structures. For individual free silver particles, which can be considered frozen in space for the duration of photon exposure, both shape and orientation are uncoveredmore » from measured scattering images. We identify regular shapes, including species with fivefold symmetry and surprisingly large aspect ratio up to particle radii of the order of 100 nm. Our approach includes scattering effects beyond Born’s approximation and is remarkably efficient—opening up new routes in ultrafast nanophysics and free-electron laser science« less

  13. Magnetism studies using resonant, coherent, x-ray scattering...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    where the scattering vector q that can only be reached in reflection. The method is Fourier transform holography, where the exit wave from a sample interferes with a reference...

  14. X-ray Diffuse Scattering Measurements of Nucleation Dynamics...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    ... The spontaneous development of voids (green circles) below the surface (red circles) is observed, leading to a quasi-divergence in the low-Q scattering. surface region for laser ...

  15. Resonant Soft X-Ray Scattering of Tri-Block Copolymers

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Resonant Soft X-Ray Scattering of Tri-Block Copolymers Resonant Soft X-Ray Scattering of Tri-Block Copolymers Print Wednesday, 30 May 2012 00:00 In principle, tri-block copolymers (tri-BCPs), consisting of three chemically distinct polymers covalently joined together at the ends of each polymer chain, can serve as scaffolds and templates for fabricating a vast number of nanostructures. While quantitatively understanding the details of the morphology and the manner in which the different blocks

  16. OSTIblog Articles in the National School on Neutron and X-ray Scattering

    Office of Scientific and Technical Information (OSTI)

    (NXS) Topic | OSTI, US Dept of Energy Office of Scientific and Technical Information School on Neutron and X-ray Scattering (NXS) Topic The NXS Class of 2014 by Kathy Chambers 19 Nov, 2014 in Every summer for the past 16 years, the Department of Energy has invited the best and brightest graduates from across the country to attend the National School on Neutron and X-ray Scattering (NXS). This year, 65 graduate students attending North American universities, and studying physics, chemistry,

  17. In Situ X-Ray Scattering Helps Optimize Printed Solar Cells

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    In Situ X-Ray Scattering Helps Optimize Printed Solar Cells In Situ X-Ray Scattering Helps Optimize Printed Solar Cells Print Wednesday, 25 February 2015 00:00 Plastic solar cells that can be printed on flexible sheets with an ink-like solution show a lot of potential as a source of lightweight, inexpensive renewable energy. However, much of the power-conversion efficiency of such cells gets lost in the translation from small-scale lab studies to large-scale manufacturing processes. To help gain

  18. Spatial frequency spectrum of the x-ray scatter distribution in CBCT projections

    SciTech Connect (OSTI)

    Bootsma, G. J.; Verhaegen, F.; Department of Oncology, Medical Physics Unit, McGill University, Montreal, Quebec H3G 1A4 ; Jaffray, D. A.; Radiation Medicine Program, Princess Margaret Hospital, Toronto, Ontario M5G 2M9; Ontario Cancer Institute, Princess Margaret Hospital, Toronto, Ontario M5G 2M9; Department of Radiation Oncology, University of Toronto, Toronto, Ontario M5G 2M9

    2013-11-15

    Purpose: X-ray scatter is a source of significant image quality loss in cone-beam computed tomography (CBCT). The use of Monte Carlo (MC) simulations separating primary and scattered photons has allowed the structure and nature of the scatter distribution in CBCT to become better elucidated. This work seeks to quantify the structure and determine a suitable basis function for the scatter distribution by examining its spectral components using Fourier analysis.Methods: The scatter distribution projection data were simulated using a CBCT MC model based on the EGSnrc code. CBCT projection data, with separated primary and scatter signal, were generated for a 30.6 cm diameter water cylinder [single angle projection with varying axis-to-detector distance (ADD) and bowtie filters] and two anthropomorphic phantoms (head and pelvis, 360 projections sampled every 1, with and without a compensator). The Fourier transform of the resulting scatter distributions was computed and analyzed both qualitatively and quantitatively. A novel metric called the scatter frequency width (SFW) is introduced to determine the scatter distribution's frequency content. The frequency content results are used to determine a set basis functions, consisting of low-frequency sine and cosine functions, to fit and denoise the scatter distribution generated from MC simulations using a reduced number of photons and projections. The signal recovery is implemented using Fourier filtering (low-pass Butterworth filter) and interpolation. Estimates of the scatter distribution are used to correct and reconstruct simulated projections.Results: The spatial and angular frequencies are contained within a maximum frequency of 0.1 cm{sup ?1} and 7/(2?) rad{sup ?1} for the imaging scenarios examined, with these values varying depending on the object and imaging setup (e.g., ADD and compensator). These data indicate spatial and angular sampling every 5 cm and ?/7 rad (?25) can be used to properly capture the scatter

  19. Kevin Yager on the Nanoscience of Studying Scattered X-Rays

    ScienceCinema (OSTI)

    Yager; Kevin

    2014-06-04

    Kevin Yager, a scientist at Brookhaven Lab's Center for Functional Nanomaterials, discusses his research on materials spanning just billionths of a meter. Yager specializes in making new materials through meticulously guided self-assembly and probing nanoscale structures with a technique called x-ray scattering.

  20. X-ray Thomson scattering measurements of temperature and density from multi-shocked CH capsules

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Fletcher, L. B.; Glenzer, S. H.; Kritcher, A.; Pak, A.; Ma, T.; Doppner, T.; Fortmann, C.; Divol, L.; Landen, O. L.; Vorberger, J.; et al

    2013-05-24

    Proof-of-principle measurements of the electron densities, temperatures, and ionization states of spherically compressed multi-shocked CH (polystyrene) capsules have been achieved using spectrally resolved x-ray Thomson scattering. A total energy of 13.5 kJ incident on target is used to compress a 70 μm thick CH shell above solid-mass density using three coalescing shocks. Separately, a laser-produced zinc He-α x-ray source at 9 keV delayed 200 ps-800 ps after maximum compression is used to probe the plasma in the non-collective scattering regime. The data show that x-ray Thomson scattering enables a complete description of the time-dependent hydrodynamic evolution of shock-compressed CH capsules,more » with a maximum measured density of ρ > 6 g cm–3. Additionally, the results demonstrate that accurate measurements of x-ray scattering from bound-free transitions in the CH plasma demonstrate strong evidence that continuum lowering is the primary ionization mechanism of carbon L-shell electrons.« less

  1. Soft X-Ray Thomson Scattering in Warm Dense Hydrogen at FLASH

    SciTech Connect (OSTI)

    Faustlin, R R; Toleikis, S; Bornath, T; Doppner, T; Dusterer, S; Forster, E; Fortmann, C; Glenzer, S H; Gode, S; Gregori, G; Irsig, R; Laarmann, T; Lee, H J; Li, B; Meiwes-Broer, K; Mithen, J; Przystawik, A; Redlin, H; Redmer, R; Reinholz, H; Ropke, G; Tavella, F; Thiele, R; Tiggesbaumker, J; Uschmann, I; Zastrau, U; Tschentscher, T

    2009-07-15

    We present collective Thomson scattering with soft x-ray free electron laser radiation as a method to track the evolution of warm dense matter plasmas with {approx}200 fs time resolution. In a pump-probe scheme an 800 nm laser heats a 20 {micro}m hydrogen droplet to the plasma state. After a variable time delay in the order of ps the plasma is probed by an x-ray ultra violet (XUV) pulse which scatters from the target and is recorded spectrally. Alternatively, in a self-Thomson scattering experiment, a single XUV pulse heats the target while a portion of its photons are being scattered probing the target. From such inelastic x-ray scattering spectra free electron temperature and density can be inferred giving insight on relaxation time scales in plasmas as well as the equation of state. We prove the feasibility of this method in the XUV range utilizing the free electron laser facility in Hamburg, FLASH. We recorded Thomson scattering spectra for hydrogen plasma, both in the self-scattering and in the pump-probe mode using optical laser heating.

  2. High energy x-ray phase contrast CT using glancing-angle grating interferometers

    SciTech Connect (OSTI)

    Sarapata, A.; Stayman, J. W.; Siewerdsen, J. H.; Finkenthal, M.; Stutman, D.; Pfeiffer, F.

    2014-02-15

    Purpose: The authors present initial progress toward a clinically compatible x-ray phase contrast CT system, using glancing-angle x-ray grating interferometry to provide high contrast soft tissue images at estimated by computer simulation dose levels comparable to conventional absorption based CT. Methods: DPC-CT scans of a joint phantom and of soft tissues were performed in order to answer several important questions from a clinical setup point of view. A comparison between high and low fringe visibility systems is presented. The standard phase stepping method was compared with sliding window interlaced scanning. Using estimated dose values obtained with a Monte-Carlo code the authors studied the dependence of the phase image contrast on exposure time and dose. Results: Using a glancing angle interferometer at high x-ray energy (∼45 keV mean value) in combination with a conventional x-ray tube the authors achieved fringe visibility values of nearly 50%, never reported before. High fringe visibility is shown to be an indispensable parameter for a potential clinical scanner. Sliding window interlaced scanning proved to have higher SNRs and CNRs in a region of interest and to also be a crucial part of a low dose CT system. DPC-CT images of a soft tissue phantom at exposures in the range typical for absorption based CT of musculoskeletal extremities were obtained. Assuming a human knee as the CT target, good soft tissue phase contrast could be obtained at an estimated absorbed dose level around 8 mGy, similar to conventional CT. Conclusions: DPC-CT with glancing-angle interferometers provides improved soft tissue contrast over absorption CT even at clinically compatible dose levels (estimated by a Monte-Carlo computer simulation). Further steps in image processing, data reconstruction, and spectral matching could make the technique fully clinically compatible. Nevertheless, due to its increased scan time and complexity the technique should be thought of not as

  3. Predicting X-ray diffuse scattering from translation–libration–screw structural ensembles

    SciTech Connect (OSTI)

    Van Benschoten, Andrew H.; Afonine, Pavel V.; Terwilliger, Thomas C.; Wall, Michael E.; Jackson, Colin J.; Sauter, Nicholas K.; Adams, Paul D.; Urzhumtsev, Alexandre; Fraser, James S.

    2015-07-28

    Identifying the intramolecular motions of proteins and nucleic acids is a major challenge in macromolecular X-ray crystallography. Because Bragg diffraction describes the average positional distribution of crystalline atoms with imperfect precision, the resulting electron density can be compatible with multiple models of motion. Diffuse X-ray scattering can reduce this degeneracy by reporting on correlated atomic displacements. Although recent technological advances are increasing the potential to accurately measure diffuse scattering, computational modeling and validation tools are still needed to quantify the agreement between experimental data and different parameterizations of crystalline disorder. A new tool, phenix.diffuse, addresses this need by employing Guinier's equation to calculate diffuse scattering from Protein Data Bank (PDB)-formatted structural ensembles. As an example case, phenix.diffuse is applied to translation–libration–screw (TLS) refinement, which models rigid-body displacement for segments of the macromolecule. To enable the calculation of diffuse scattering from TLS-refined structures, phenix.tls_as_xyz builds multi-model PDB files that sample the underlying T, L and S tensors. In the glycerophosphodiesterase GpdQ, alternative TLS-group partitioning and different motional correlations between groups yield markedly dissimilar diffuse scattering maps with distinct implications for molecular mechanism and allostery. These methods demonstrate how, in principle, X-ray diffuse scattering could extend macromolecular structural refinement, validation and analysis.

  4. Predicting X-ray diffuse scattering from translation–libration–screw structural ensembles

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Van Benschoten, Andrew H.; Afonine, Pavel V.; Terwilliger, Thomas C.; Wall, Michael E.; Jackson, Colin J.; Sauter, Nicholas K.; Adams, Paul D.; Urzhumtsev, Alexandre; Fraser, James S.

    2015-07-28

    Identifying the intramolecular motions of proteins and nucleic acids is a major challenge in macromolecular X-ray crystallography. Because Bragg diffraction describes the average positional distribution of crystalline atoms with imperfect precision, the resulting electron density can be compatible with multiple models of motion. Diffuse X-ray scattering can reduce this degeneracy by reporting on correlated atomic displacements. Although recent technological advances are increasing the potential to accurately measure diffuse scattering, computational modeling and validation tools are still needed to quantify the agreement between experimental data and different parameterizations of crystalline disorder. A new tool, phenix.diffuse, addresses this need by employing Guinier'smore » equation to calculate diffuse scattering from Protein Data Bank (PDB)-formatted structural ensembles. As an example case, phenix.diffuse is applied to translation–libration–screw (TLS) refinement, which models rigid-body displacement for segments of the macromolecule. To enable the calculation of diffuse scattering from TLS-refined structures, phenix.tls_as_xyz builds multi-model PDB files that sample the underlying T, L and S tensors. In the glycerophosphodiesterase GpdQ, alternative TLS-group partitioning and different motional correlations between groups yield markedly dissimilar diffuse scattering maps with distinct implications for molecular mechanism and allostery. These methods demonstrate how, in principle, X-ray diffuse scattering could extend macromolecular structural refinement, validation and analysis.« less

  5. The diagnostic capability of x-ray scattering parameters for the characterization of breast cancer

    SciTech Connect (OSTI)

    Elshemey, Wael M.; Desouky, Omar S.; Fekry, Mostafa M.; Talaat, Sahar M.; Elsayed, Anwar A.

    2010-08-15

    Purpose: The evaluation of the diagnostic capability of easy to measure x-ray scattering profile characterization parameters for the detection of breast cancer in excised samples. The selected parameters are the full width at half maximum (FWHM) and area under the x-ray scattering profile of breast tissue in addition to the ratio of scattering intensities (I{sub 2}/I{sub 1}%) at 1.6 nm{sup -1} to that at 1.1 nm{sup -1} (corresponding to scattering from soft and adipose tissues, respectively). Methods: A histopathologist is asked to classify 36 excised breast tissue samples into healthy or malignant. A conventional x-ray diffractometer is used to acquire the scattering profiles of the investigated samples. The values of three profile characterization parameters are calculated and the diagnostic capability of each is evaluated by determining the optimal cutoffs of scatter diagrams, calculating the diagnostic indices, and plotting the receiver operating characteristic (ROC) curves. Results: At the calculated optimal cutoff for each of the examined parameters, the sensitivity ranged from 78% (for area under curve) up to 94% (for FWHM), the specificity ranged from 94%[for I{sub 2}/I{sub 1}% and area under curve] up to 100% (for FWHM), and the diagnostic accuracy ranged from 86% (for area under curve) up to 97% (for FWHM). The area under the ROC curves is greater than 0.95 for all of the investigated parameters, reflecting a highly accurate diagnostic performance. Conclusions: The discussed tests offered a means to quantitatively evaluate the performance of the suggested breast tissue x-ray scattering characterization parameters. The performance results are promising, indicating that the evaluated parameters would be considered a tool for fast, on spot probing of breast cancer in excised tissue samples.

  6. The life science X-ray scattering beamline at NSLS-II

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    DiFabio, Jonathan; Yang, Lin; Chodankar, Shirish; Pjerov, Sal; Jakoncic, Jean; Lucas, Michael; Krywka, Christina; Graziano, Vito

    2015-09-30

    We report the current development status of the High Brightness X-ray Scattering for Life Sciences (or Life Science X-ray Scattering, LiX) beamline at the NSLS-II facility of Brookhaven National Laboratory. This instrument will operate in the x-ray energy range of 2.1-18 keV, provide variable beam sizes from 1 micron to ~0.5 mm, and support user experiments in three scientific areas: (1) high-throughput solution scattering, in-line size exclusion chromatography and flow mixers-based time-resolved solution scattering of biological macro-molecules, (2) diffraction from single- and multi-layered lipid membranes, and (3) scattering-based scanning probe imaging of biological tissues. In order to satisfy the beammore » stability required for these experiments and to switch rapidly between different types of experiments, we have adopted a secondary source with refractive lenses for secondary focusing, a detector system consisting of three Pilatus detectors, and specialized experimental modules that can be quickly exchanged and each dedicated to a defined set of experiments. The construction of this beamline is on schedule for completion in September 2015. User experiments are expected to start in Spring 2016.« less

  7. Inelastic x-ray scattering studies on dynamic structure factor of polymeric liquid Se under pressure

    SciTech Connect (OSTI)

    Inui, Masanori; Kajihara, Yukio; Kimura, Koji; Matsuda, Kazuhiro; Ohara, Koji; Tsutsui, Satoshi; Ishikawa, Daisuke

    2015-08-17

    Inelastic X-ray scattering measurements at 25 MPa using synchrotron radiation were carried out for semiconducting liquid Se at high temperatures up to 1673 K. The excitation energy of the acoustic mode disperses approximately 10-50 % faster than the ultrasonic sound velocity in the observed temperature range while the ultrasonic sound rapidly slows down with increasing temperature. We carried out X-ray scattering measurements and found that the average coordination number at 1673 K is 1.3, indicating that the high temperature liquid consists of short chain molecules. These results suggest that weakening of the interatomic interaction is correlated with breaking of polymeric chain molecules.

  8. Resonant Soft X-Ray Scattering of Tri-Block Copolymers

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Resonant Soft X-Ray Scattering of Tri-Block Copolymers Print In principle, tri-block copolymers (tri-BCPs), consisting of three chemically distinct polymers covalently joined together at the ends of each polymer chain, can serve as scaffolds and templates for fabricating a vast number of nanostructures. While quantitatively understanding the details of the morphology and the manner in which the different blocks interact with surfaces and interfaces is critical to success, previous experiments

  9. Resonant Soft X-Ray Scattering of Tri-Block Copolymers

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Resonant Soft X-Ray Scattering of Tri-Block Copolymers Print In principle, tri-block copolymers (tri-BCPs), consisting of three chemically distinct polymers covalently joined together at the ends of each polymer chain, can serve as scaffolds and templates for fabricating a vast number of nanostructures. While quantitatively understanding the details of the morphology and the manner in which the different blocks interact with surfaces and interfaces is critical to success, previous experiments

  10. Resonant Soft X-Ray Scattering of Tri-Block Copolymers

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Resonant Soft X-Ray Scattering of Tri-Block Copolymers Print In principle, tri-block copolymers (tri-BCPs), consisting of three chemically distinct polymers covalently joined together at the ends of each polymer chain, can serve as scaffolds and templates for fabricating a vast number of nanostructures. While quantitatively understanding the details of the morphology and the manner in which the different blocks interact with surfaces and interfaces is critical to success, previous experiments

  11. Resonant Soft X-Ray Scattering of Tri-Block Copolymers

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Resonant Soft X-Ray Scattering of Tri-Block Copolymers Print In principle, tri-block copolymers (tri-BCPs), consisting of three chemically distinct polymers covalently joined together at the ends of each polymer chain, can serve as scaffolds and templates for fabricating a vast number of nanostructures. While quantitatively understanding the details of the morphology and the manner in which the different blocks interact with surfaces and interfaces is critical to success, previous experiments

  12. Resonant Soft X-Ray Scattering of Tri-Block Copolymers

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Resonant Soft X-Ray Scattering of Tri-Block Copolymers Print In principle, tri-block copolymers (tri-BCPs), consisting of three chemically distinct polymers covalently joined together at the ends of each polymer chain, can serve as scaffolds and templates for fabricating a vast number of nanostructures. While quantitatively understanding the details of the morphology and the manner in which the different blocks interact with surfaces and interfaces is critical to success, previous experiments

  13. Resonant Soft X-Ray Scattering of Tri-Block Copolymers

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Resonant Soft X-Ray Scattering of Tri-Block Copolymers Print In principle, tri-block copolymers (tri-BCPs), consisting of three chemically distinct polymers covalently joined together at the ends of each polymer chain, can serve as scaffolds and templates for fabricating a vast number of nanostructures. While quantitatively understanding the details of the morphology and the manner in which the different blocks interact with surfaces and interfaces is critical to success, previous experiments

  14. Resonant Soft X-Ray Scattering of Tri-Block Copolymers

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Resonant Soft X-Ray Scattering of Tri-Block Copolymers Print In principle, tri-block copolymers (tri-BCPs), consisting of three chemically distinct polymers covalently joined together at the ends of each polymer chain, can serve as scaffolds and templates for fabricating a vast number of nanostructures. While quantitatively understanding the details of the morphology and the manner in which the different blocks interact with surfaces and interfaces is critical to success, previous experiments

  15. X-ray and neutron scattering studies of the complex compounds | Stanford

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Synchrotron Radiation Lightsource X-ray and neutron scattering studies of the complex compounds Wednesday, September 25, 2013 - 1:00pm SLAC, Conference Room 137-322 Presented by Dr. Hoyoung Jang, Max Planck Institute for Solid State Research in Stuttgart, Germany In condensed matter physics, in particular a field of complex oxide materials, most of the research-activity is focusing on finding a new functionality in materials as well as its understanding. In this fashion, during past few

  16. Structure and dynamics of cadmium telluride studied by x-ray and inelastic neutron scattering

    SciTech Connect (OSTI)

    Niedziela, J. L., E-mail: niedzielajl@ornl.gov [Instrument and Source Division, Neutron Sciences Directorate, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States); Stone, M. B., E-mail: stonemb@ornl.gov [Quantum Condensed Matter Division, Neutron Sciences Directorate, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States)

    2014-09-08

    We present a combined study of density functional theory, x-ray diffraction, and inelastic neutron scattering examining the temperature dependent structure and lattice dynamics of commercially available cadmium telluride. A subtle change in the structure is evinced near 80?K, which manifests also in the measured phonon density of states. There is no change to the long-range ordered structure. The implications of the change in relation to structural defects are discussed.

  17. Structure and dynamics of cadmium telluride studied by x-ray and inelastic neutron scattering

    SciTech Connect (OSTI)

    Niedziela, Jennifer L [ORNL; Stone, Matthew B [ORNL

    2014-01-01

    We present a combined study of density functional theory, x-ray diffraction, and inelastic neutron scattering examining the temperature dependent structure and lattice dynamics of commercially available cadmium telluride. A subtle change in the structure is evinced near 80~K, which manifests also in the measured phonon density of states. There is no change to the long-range ordered structure. The implications of the change in relation to structural defects are discussed.

  18. X-ray scatter imaging of hepatocellular carcinoma in a mouse model using nanoparticle contrast agents

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Rand, Danielle; Derdak, Zoltan; Carlson, Rolf; Wands, Jack R.; Rose-Petruck, Christoph

    2015-10-29

    Hepatocellular carcinoma (HCC) is one of the most common malignant tumors worldwide and is almost uniformly fatal. Current methods of detection include ultrasound examination and imaging by CT scan or MRI; however, these techniques are problematic in terms of sensitivity and specificity, and the detection of early tumors (<1 cm diameter) has proven elusive. Better, more specific, and more sensitive detection methods are therefore urgently needed. Here we discuss the application of a newly developed x-ray imaging technique called Spatial Frequency Heterodyne Imaging (SFHI) for the early detection of HCC. SFHI uses x-rays scattered by an object to form anmore » image and is more sensitive than conventional absorption-based x-radiography. We show that tissues labeled in vivo with gold nanoparticle contrast agents can be detected using SFHI. We also demonstrate that directed targeting and SFHI of HCC tumors in a mouse model is possible through the use of HCC-specific antibodies. As a result, the enhanced sensitivity of SFHI relative to currently available techniques enables the x-ray imaging of tumors that are just a few millimeters in diameter and substantially reduces the amount of nanoparticle contrast agent required for intravenous injection relative to absorption-based x-ray imaging.« less

  19. X-ray scatter imaging of hepatocellular carcinoma in a mouse model using nanoparticle contrast agents

    SciTech Connect (OSTI)

    Rand, Danielle; Derdak, Zoltan; Carlson, Rolf; Wands, Jack R.; Rose-Petruck, Christoph

    2015-10-29

    Hepatocellular carcinoma (HCC) is one of the most common malignant tumors worldwide and is almost uniformly fatal. Current methods of detection include ultrasound examination and imaging by CT scan or MRI; however, these techniques are problematic in terms of sensitivity and specificity, and the detection of early tumors (<1 cm diameter) has proven elusive. Better, more specific, and more sensitive detection methods are therefore urgently needed. Here we discuss the application of a newly developed x-ray imaging technique called Spatial Frequency Heterodyne Imaging (SFHI) for the early detection of HCC. SFHI uses x-rays scattered by an object to form an image and is more sensitive than conventional absorption-based x-radiography. We show that tissues labeled in vivo with gold nanoparticle contrast agents can be detected using SFHI. We also demonstrate that directed targeting and SFHI of HCC tumors in a mouse model is possible through the use of HCC-specific antibodies. As a result, the enhanced sensitivity of SFHI relative to currently available techniques enables the x-ray imaging of tumors that are just a few millimeters in diameter and substantially reduces the amount of nanoparticle contrast agent required for intravenous injection relative to absorption-based x-ray imaging.

  20. X-ray phase-contrast imaging with an Inverse Compton Scattering source

    SciTech Connect (OSTI)

    Endrizzi, M.; Carpinelli, M.; Oliva, P.; Golosio, B.; Delogu, P.; Stefanini, A.; Gureyev, T. E.; Bottigli, U.

    2010-07-23

    Single-shot in-line phase-contrast imaging with the Inverse Compton Scattering X-ray source available at ATF (Accelerator Test Facility) at Brookhaven National Laboratory is experimentally demonstrated. Phase-contrast images of polymer wires are obtained with a single X-ray pulse whose time length is about 1 picosecond. The edge-enhancement effect is clearly visible in the images and simulations show a quantitative agreement with experimental data. A phase-retrieval step in the image processing leads to a accurate estimation of the projected thickness of our samples. Finally, a single-shot image of a wasp is presented as an example of a biological sample.

  1. Attosecond Thomson-scattering x-ray source driven by laser-based electron acceleration

    SciTech Connect (OSTI)

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

    2013-10-21

    The possibility of producing attosecond x-rays through Thomson scattering of laser light off laser-driven relativistic electron beams is investigated. For a ≤200-as, tens-MeV electron bunch produced with laser ponderomotive-force acceleration in a plasma wire, exceeding 10{sup 6} photons/s in the form of ∼160 as pulses in the range of 3–300 keV are predicted, with a peak brightness of ≥5 × 10{sup 20} photons/(s mm{sup 2} mrad{sup 2} 0.1% bandwidth). Our study suggests that the physical scheme discussed in this work can be used for an ultrafast (attosecond) x-ray source, which is the most beneficial for time-resolved atomic physics, dubbed “attosecond physics.”.

  2. An angle-dependent estimation of CT x-ray spectrum from rotational transmission measurements

    SciTech Connect (OSTI)

    Lin, Yuan Samei, Ehsan; Ramirez-Giraldo, Juan Carlos; Gauthier, Daniel J.; Stierstorfer, Karl

    2014-06-15

    Purpose: Computed tomography (CT) performance as well as dose and image quality is directly affected by the x-ray spectrum. However, the current assessment approaches of the CT x-ray spectrum require costly measurement equipment and complicated operational procedures, and are often limited to the spectrum corresponding to the center of rotation. In order to address these limitations, the authors propose an angle-dependent estimation technique, where the incident spectra across a wide range of angular trajectories can be estimated accurately with only a single phantom and a single axial scan in the absence of the knowledge of the bowtie filter. Methods: The proposed technique uses a uniform cylindrical phantom, made of ultra-high-molecular-weight polyethylene and positioned in an off-centered geometry. The projection data acquired with an axial scan have a twofold purpose. First, they serve as a reflection of the transmission measurements across different angular trajectories. Second, they are used to reconstruct the cross sectional image of the phantom, which is then utilized to compute the intersection length of each transmission measurement. With each CT detector element recording a range of transmission measurements for a single angular trajectory, the spectrum is estimated for that trajectory. A data conditioning procedure is used to combine information from hundreds of collected transmission measurements to accelerate the estimation speed, to reduce noise, and to improve estimation stability. The proposed spectral estimation technique was validated experimentally using a clinical scanner (Somatom Definition Flash, Siemens Healthcare, Germany) with spectra provided by the manufacturer serving as the comparison standard. Results obtained with the proposed technique were compared against those obtained from a second conventional transmission measurement technique with two materials (i.e., Cu and Al). After validation, the proposed technique was applied to measure

  3. A high resolution and large solid angle x-ray Raman spectroscopy end-station at the Stanford Synchrotron Radiation Lightsource

    SciTech Connect (OSTI)

    Sokaras, D.; Nordlund, D.; Weng, T.-C.; Velikov, P.; Wenger, D.; Garachtchenko, A.; George, M.; Borzenets, V.; Johnson, B.; Rabedeau, T.; Mori, R. Alonso; Bergmann, U.; Qian, Q.

    2012-04-15

    We present a new x-ray Raman spectroscopy end-station recently developed, installed, and operated at the Stanford Synchrotron Radiation Lightsource. The end-station is located at wiggler beamline 6-2 equipped with two monochromators-Si(111) and Si(311) as well as collimating and focusing optics. It consists of two multi-crystal Johann type spectrometers arranged on intersecting Rowland circles of 1 m diameter. The first one, positioned at the forward scattering angles (low-q), consists of 40 spherically bent and diced Si(110) crystals with 100 mm diameters providing about 1.9% of 4{pi} sr solid angle of detection. When operated in the (440) order in combination with the Si (311) monochromator, an overall energy resolution of 270 meV is obtained at 6462.20 eV. The second spectrometer, consisting of 14 spherically bent Si(110) crystal analyzers (not diced), is positioned at the backward scattering angles (high-q) enabling the study of non-dipole transitions. The solid angle of this spectrometer is about 0.9% of 4{pi} sr, with a combined energy resolution of 600 meV using the Si (311) monochromator. These features exceed the specifications of currently existing relevant instrumentation, opening new opportunities for the routine application of this photon-in/photon-out hard x-ray technique to emerging research in multidisciplinary scientific fields, such as energy-related sciences, material sciences, physical chemistry, etc.

  4. In Situ X-Ray Scattering Helps Optimize Printed Solar Cells

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    In Situ X-Ray Scattering Helps Optimize Printed Solar Cells Print Plastic solar cells that can be printed on flexible sheets with an ink-like solution show a lot of potential as a source of lightweight, inexpensive renewable energy. However, much of the power-conversion efficiency of such cells gets lost in the translation from small-scale lab studies to large-scale manufacturing processes. To help gain an understanding of why that happens, researchers have developed at the ALS a miniature

  5. In Situ X-Ray Scattering Helps Optimize Printed Solar Cells

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    In Situ X-Ray Scattering Helps Optimize Printed Solar Cells Print Plastic solar cells that can be printed on flexible sheets with an ink-like solution show a lot of potential as a source of lightweight, inexpensive renewable energy. However, much of the power-conversion efficiency of such cells gets lost in the translation from small-scale lab studies to large-scale manufacturing processes. To help gain an understanding of why that happens, researchers have developed at the ALS a miniature

  6. In Situ X-Ray Scattering Helps Optimize Printed Solar Cells

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    In Situ X-Ray Scattering Helps Optimize Printed Solar Cells Print Plastic solar cells that can be printed on flexible sheets with an ink-like solution show a lot of potential as a source of lightweight, inexpensive renewable energy. However, much of the power-conversion efficiency of such cells gets lost in the translation from small-scale lab studies to large-scale manufacturing processes. To help gain an understanding of why that happens, researchers have developed at the ALS a miniature

  7. In Situ X-Ray Scattering Helps Optimize Printed Solar Cells

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    In Situ X-Ray Scattering Helps Optimize Printed Solar Cells Print Plastic solar cells that can be printed on flexible sheets with an ink-like solution show a lot of potential as a source of lightweight, inexpensive renewable energy. However, much of the power-conversion efficiency of such cells gets lost in the translation from small-scale lab studies to large-scale manufacturing processes. To help gain an understanding of why that happens, researchers have developed at the ALS a miniature

  8. In Situ X-Ray Scattering Helps Optimize Printed Solar Cells

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    In Situ X-Ray Scattering Helps Optimize Printed Solar Cells Print Plastic solar cells that can be printed on flexible sheets with an ink-like solution show a lot of potential as a source of lightweight, inexpensive renewable energy. However, much of the power-conversion efficiency of such cells gets lost in the translation from small-scale lab studies to large-scale manufacturing processes. To help gain an understanding of why that happens, researchers have developed at the ALS a miniature

  9. In Situ X-Ray Scattering Helps Optimize Printed Solar Cells

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    In Situ X-Ray Scattering Helps Optimize Printed Solar Cells Print Plastic solar cells that can be printed on flexible sheets with an ink-like solution show a lot of potential as a source of lightweight, inexpensive renewable energy. However, much of the power-conversion efficiency of such cells gets lost in the translation from small-scale lab studies to large-scale manufacturing processes. To help gain an understanding of why that happens, researchers have developed at the ALS a miniature

  10. In Situ X-Ray Scattering Helps Optimize Printed Solar Cells

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    In Situ X-Ray Scattering Helps Optimize Printed Solar Cells Print Plastic solar cells that can be printed on flexible sheets with an ink-like solution show a lot of potential as a source of lightweight, inexpensive renewable energy. However, much of the power-conversion efficiency of such cells gets lost in the translation from small-scale lab studies to large-scale manufacturing processes. To help gain an understanding of why that happens, researchers have developed at the ALS a miniature

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

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Chubar, Oleg; Geloni, Gianluca; Kocharyan, Vitali; Madsen, Anders; Saldin, Evgeni; Serkez, Svitozar; Shvyd'ko, Yuri; Sutter, John

    2016-02-12

    Inelastic X-ray scattering (IXS) is an important tool for studies of equilibrium dynamics in condensed matter. A new spectrometer recently proposed for ultra-high-resolution IXS (UHRIX) has achieved 0.6 meV and 0.25 nm₋1spectral and momentum-transfer resolutions, respectively. However, further improvements down to 0.1 meV and 0.02 nm₋1are required to close the gap in energy–momentum space between high- and low-frequency probes. It is shown that this goal can be achieved by further optimizing the X-ray optics and by increasing the spectral flux of the incident X-ray pulses. UHRIX performs best at energies from 5 to 10 keV, where a combination of self-seedingmore » and undulator tapering at the SASE-2 beamline of the European XFEL promises up to a 100-fold increase in average spectral flux compared with nominal SASE pulses at saturation, or three orders of magnitude more than what is possible with storage-ring-based radiation sources. Wave-optics calculations show that about 7 × 1012 photons s₋1in a 90 µeV bandwidth can be achieved on the sample. Ultimately, this will provide unique new possibilities for dynamics studies by IXS.« less

  12. Measuring and modeling diffuse scattering in protein X-ray crystallography

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Van Benschoten, Andrew H.; Liu, Lin; Gonzalez, Ana; Brewster, Aaron S.; Sauter, Nicholas K.; Fraser, James S.; Wall, Michael E.

    2016-03-28

    X-ray diffraction has the potential to provide rich information about the structural dynamics of macromolecules. To realize this potential, both Bragg scattering, which is currently used to derive macromolecular structures, and diffuse scattering, which reports on correlations in charge density variations, must be measured. Until now, measurement of diffuse scattering from protein crystals has been scarce because of the extra effort of collecting diffuse data. Here, we present 3D measurements of diffuse intensity collected from crystals of the enzymes cyclophilin A and trypsin. The measurements were obtained from the same X-ray diffraction images as the Bragg data, using best practicesmore » for standard data collection. To model the underlying dynamics in a practical way that could be used during structure refinement, we tested translation–libration–screw (TLS), liquid-like motions (LLM), and coarse-grained normal-modes (NM) models of protein motions. The LLM model provides a global picture of motions and was refined against the diffuse data, whereas the TLS and NM models provide more detailed and distinct descriptions of atom displacements, and only used information from the Bragg data. Whereas different TLS groupings yielded similar Bragg intensities, they yielded different diffuse intensities, none of which agreed well with the data. In contrast, both the LLM and NM models agreed substantially with the diffuse data. In conclusion, these results demonstrate a realistic path to increase the number of diffuse datasets available to the wider biosciences community and indicate that dynamics-inspired NM structural models can simultaneously agree with both Bragg and diffuse scattering.« less

  13. SMB, X-ray Emission Spectroscopy

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    include X-ray Emission Spectroscopy (XES), Resonant Inelastic X-ray Scattering (RIXS), High Energy Resolution Fluorescence Detection (HERFD) and X-ray Raman Spectroscopy (XRS). ...

  14. X-ray Imaging Workshop

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    microscopy (PEEM), angle resolved photoemission spectroscopy (ARPES), coherent diffraction imaging, x-ray microscopy, micro-tomography, holographic imaging, and x-ray...

  15. An In-situ X-ray Scattering Study During Uniaxial Stretching of Ionic Liquid/Ultra-high Molecular Weight Polyethylene Blends

    SciTech Connect (OSTI)

    X Li; Y Mao; H Ma; F Zuo; B Hsiao; B Chu

    2011-12-31

    An ionic liquid (IL) 1-docosanyl-3-methylimidazolium bromide was incorporated into ultra-high molecular weight polyethylene (UHMWPE) and formed IL/UHMWPE blends by solution mixing. The structure evolution of these blends during uniaxial stretching was followed by in-situ synchrotron wide-angle X-ray diffraction (WAXD) and small-angle X-ray scattering (SAXS) techniques. During deformation at room temperature, deformation-induced phase transformation from orthorhombic to monoclinic phase was observed in both IL/UHMWPE blends and neat UHMWPE. The elongation-to-break ratios of IL/UHMWPE blends were found to increase by 2-3 times compared with that of pure UHMWPE, while the tensile strength remained about the same. In contrast, during deformation at high temperature (120 C), no phase transformation was observed. However, the blend samples showed much better toughness, higher crystal orientation and higher tilting extent of lamellar structure at high strains.

  16. Scattered hard X-ray and γ-ray generation from a chromatic electron beam

    SciTech Connect (OSTI)

    Coleman, J. E.; Welch, D. R.; Miller, C. L.

    2015-11-14

    An array of photon diagnostics has been deployed on a high power relativistic electron beam diode. Electrons are extracted through a 17.8 cm diode from the surface discharge of a carbon fiber velvet cathode with a nominal diode voltage of 3.8 MV. <10% of the 100 ns electron pulse is composed of off energy electrons (1–3 MeV) accelerated during the rise and fall of the pulse that impact the stainless steel beam pipe and generate a Bremsstrahlung spectrum of 0.1–3 MeV photons with a total count of 10{sup 11}. The principal objective of these experiments is to quantify the electron beam dynamics and spatial dynamics of the hard X-ray and γ-ray flux generated in the diode region. A qualitative comparison of experimental and calculated results are presented, including time and energy resolved electron beam propagation and scattered photon measurements with X-ray PIN diodes and a photomultiplier tube indicating a dose dependence on the diode voltage >V{sup 4} and detected photon counts of nearly 10{sup 6} at a radial distance of 1 m which corresponds to dose ∼40 μrad at 1 m.

  17. In Situ X-Ray Scattering Helps Optimize Printed Solar Cells

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    that can operate in an x-ray beamline. With this capability, researchers can, for the first time, apply grazing-incidence x-ray diffraction (GIXD) and grazing-incidence...

  18. The simultaneous measurement of energy and linear polarization of the scattered radiation in resonant inelastic soft x-ray scattering

    SciTech Connect (OSTI)

    Braicovich, L. Minola, M.; Dellea, G.; Ghiringhelli, G.; Le Tacon, M.; Moretti Sala, M.; Morawe, C.; Peffen, J.-Ch.; Yakhou, F.; Brookes, N. B.; Supruangnet, R.

    2014-11-15

    Resonant Inelastic X-ray Scattering (RIXS) in the soft x-ray range is an element-specific energy-loss spectroscopy used to probe the electronic and magnetic excitations in strongly correlated solids. In the recent years, RIXS has been progressing very quickly in terms of energy resolution and understanding of the experimental results, but the interpretation of spectra could further improve, sometimes decisively, from a full knowledge of the polarization of incident and scattered photons. Here we present the first implementation, in a high resolution soft-RIXS spectrometer used to analyze the scattered radiation, of a device allowing the measurement of the degree of linear polarization. The system, based on a graded W/B{sub 4}C multilayer mirror installed in proximity of the CCD detector, has been installed on the AXES spectrometer at the ESRF (European Synchrotron Radiation Facility); it has been fully characterized and it has been used for a demonstration experiment at the Cu L{sub 3} edge on a high-T{sub c} superconducting cuprate. The loss in efficiency suffered by the spectrometer equipped with this test facility was a factor 17.5. We propose also a more advanced version, suitable for a routine use on the next generation of RIXS spectrometers and with an overall efficiency up to 10%.

  19. Nuclear resonant inelastic X-ray scattering at high pressure and low temperature

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Bi, Wenli; Zhao, Jiyong; Lin, Jung -Fu; Jia, Quanjie; Hu, Michael Y.; Jin, Changqing; Ferry, Richard; Yang, Wenge; Struzhkin, Viktor; Alp, E. Ercan

    2015-01-01

    In this study, a new synchrotron radiation experimental capability of coupling nuclear resonant inelastic X-ray scattering with the cryogenically cooled high-pressure diamond anvil cell technique is presented. The new technique permits measurements of phonon density of states at low temperature and high pressure simultaneously, and can be applied to studies of phonon contribution to pressure- and temperature-induced magnetic, superconducting and metal–insulator transitions in resonant isotope-bearing materials. In this report, a pnictide sample, EuFe2As2, is used as an example to demonstrate this new capability at beamline 3-ID of the Advanced Photon Source, Argonne National Laboratory. A detailed description of the technicalmore » development is given. The Fe-specific phonon density of states and magnetism from the Fe sublattice in Eu57Fe2As2 at high pressure and low temperature were derived by using this new capability.« less

  20. Nematicity in stripe ordered cuprates probed via resonant x-ray scattering

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Achkar, A. J.; Zwiebler, M.; McMahon, Christopher; He, F.; Sutarto, R.; Dijianto, Isaiah; Hao, Zhihao; Gingras, Michael J.P.; Hucker, M.; Gu, G. D.; et al

    2016-02-05

    We found that in underdoped cuprate superconductors, a rich competition occurs between superconductivity and charge density wave (CDW) order. Whether rotational symmetry-breaking (nematicity) occurs intrinsically and generically or as a consequence of other orders is under debate. Here, we employ resonant x-ray scattering in stripe-ordered superconductors (La,M)2CuO4 to probe the relationship between electronic nematicity of the Cu 3d orbitals, structure of the (La,M)2O2 layers, and CDW order. We find distinct temperature dependences for the structure of the (La,M)2O2 layers and the electronic nematicity of the CuO2 planes, with only the latter being enhanced by the onset of CDW order. Ourmore » results identify electronic nematicity as an order parameter that is distinct from a purely structural order parameter in underdoped striped cuprates.« less

  1. Flat panel X-ray detector with reduced internal scattering for improved attenuation accuracy and dynamic range

    DOE Patents [OSTI]

    Smith, Peter D.; Claytor, Thomas N.; Berry, Phillip C.; Hills, Charles R.

    2010-10-12

    An x-ray detector is disclosed that has had all unnecessary material removed from the x-ray beam path, and all of the remaining material in the beam path made as light and as low in atomic number as possible. The resulting detector is essentially transparent to x-rays and, thus, has greatly reduced internal scatter. The result of this is that x-ray attenuation data measured for the object under examination are much more accurate and have an increased dynamic range. The benefits of this improvement are that beam hardening corrections can be made accurately, that computed tomography reconstructions can be used for quantitative determination of material properties including density and atomic number, and that lower exposures may be possible as a result of the increased dynamic range.

  2. CHESS X-rays show how to grow crystals from crystals > EMC2 News...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    done one at the time. Wide-angle X-ray scattering is used for relatively smaller-scale characterization, revealing information on how atomic planes within individual...

  3. Concept to diagnose mix with imaging x-ray Thomson scattering

    SciTech Connect (OSTI)

    Keiter, Paul A.; Gamboa, Eliseo J.; Huntington, Channing M.; Kuranz, Carolyn C.

    2012-10-15

    Turbulent mixing of two fluid species is a ubiquitous problem, prevalent in systems such as inertial confinement fusion (ICF) capsule implosions, supernova remnants, and other astrophysical systems. In complex, high Reynolds number compressible high energy density (HED) flows such as these, hydrodynamic instabilities initiate the turbulent mixing process, which can then feedback and alter the mean hydrodynamic motion through nonlinear processes. In order to predict how these systems evolve under turbulent conditions, models are used. However, these models require detailed quantitative data to validate and constrain their detailed physics models as well as improve them. Providing this much needed data is currently at the forefront of HED research but is proving elusive due to a lack of available diagnostics capable of directly measuring detailed flow variables. Thomson scattering is a promising technique in this regard as it provides fundamental conditions of the flow ({rho}, T, Zbar) due to its direct interaction with the small scales of the fluid or plasma and was recently considered as a possible mix diagnostic. With the development of imaging x-ray Thomson scattering (IXRTS) obtaining spatial profiles of these variables is within reach. We propose a novel use of the IXRTS technique that will provide more detailed quantitative data required for model validation in mix experiments.

  4. X-ray scattering measurements of dissociation-induced metallization of dynamically compressed deuterium

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Davis, P.; Döppner, T.; Rygg, J. R.; Fortmann, C.; Divol, L.; Pak, A.; Fletcher, L.; Becker, A.; Holst, B.; Sperling, P.; et al

    2016-04-18

    Hydrogen, the simplest element in the universe, has a surprisingly complex phase diagram. Because of applications to planetary science, inertial confinement fusion and fundamental physics, its high-pressure properties have been the subject of intense study over the past two decades. While sophisticated static experiments have probed hydrogen’s structure at ever higher pressures, studies examining the higher-temperature regime using dynamic compression have mostly been limited to optical measurement techniques. Here we present spectrally resolved x-ray scattering measurements from plasmons in dynamically compressed deuterium. Combined with Compton scattering, and velocity interferometry to determine shock pressure and mass density, this allows us tomore » extract ionization state as a function of compression. Finally, the onset of ionization occurs close in pressure to where density functional theory-molecular dynamics (DFT-MD) simulations show molecular dissociation, suggesting hydrogen transitions from a molecular and insulating fluid to a conducting state without passing through an intermediate atomic phase.« less

  5. Crystal Dynamics of (delta) fcc Pu-Ga by High Resolution Inelastic X-Ray Scattering

    SciTech Connect (OSTI)

    Wong, J; Krisch, M; Farber, D; Occelli, F; Xu, R; Chiang, T C; Clatterbuck, D; Schwartz, A J; Wall, M; Boro, C

    2004-09-28

    We have used a microbeam on large grain sample concept to carry out an inelastic x-ray scattering experiment to map the full phonon dispersion curves of an fcc {delta}-phase Pu-Ga alloy. This approach obviates experimental difficulties with conventional inelastic neutron scattering due to the high absorption cross section of the common {sup 239}Pu isotope and the non-availability of large (mm size) single crystal materials for Pu and its alloys. A classical Born von-Karman force constant model was used to model the experimental results, and no less than 4th nearest neighbor interactions had to be included to account for the observation. Several unusual features including, a large elastic anisotropy, a small shear elastic modulus, (C{sub 11}-C{sub 12})/2, a Kohn-like anomaly in the T{sub 1}[011] branch, and a pronounced softening of the T[111] branch towards the L point in the Brillouin are found. These features can be related to the phase transitions of plutonium and to strong coupling between the crystal structure and the 5f valence instabilities. Our results represent the first full phonon dispersions ever obtained for any Pu-bearing material, thus ending a 40-year quest for this fundamental data. The phonon data also provide a critical test for theoretical treatments of highly correlated 5f electron systems as exemplified by recent dynamical mean field theory (DMFT) calculations for {delta}-plutonium.

  6. X-Ray Interactions with Matter from the Center for X-Ray Optics (CXRO)

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Henke, B. L.; Gullikson, E. M.; Davis, J. C.

    The primary interactions of low-energy x-rays within condensed matter, viz. photoabsorption and coherent scattering, are described for photon energies outside the absorption threshold regions by using atomic scattering factors. The atomic scattering factors may be accurately determined from the atomic photoabsorption cross sections using modified Kramers-Kronig dispersion relations. From a synthesis of the currently available experimental data and recent theoretical calculations for photoabsorption, the angle-independent, forward-scattering components of the atomic scattering factors have been thus semiempirically determined and tabulated here for 92 elements and for the region 50-30,000 eV. Atomic scattering factors for all angles of coherent scattering and at the higher photon energies are obtained from these tabulated forward-scattering values by adding a simple angle-dependent form-factor correction. The incoherent scattering contributions that become significant for the light elements at the higher photon energies are similarly determined. The basic x-ray interaction relations that are used in applied x-ray physics are presented here in terms of the atomic scattering factors. The bulk optical constants are also related to the atomic scattering factors. These atomic and optical relations are applied to the detailed calculation of the reflectivity characteristics of a series of practical x-ray mirror, multilayer, and crystal monochromators. Comparisons of the results of this semiempirical,"atom-like", description of x-ray interactions for the low-energy region with those of experiment and ab initio theory are presented.

  7. Large angle solid state position sensitive x-ray detector system

    DOE Patents [OSTI]

    Kurtz, David S.; Ruud, Clay O.

    1998-01-01

    A method and apparatus for x-ray measurement of certain properties of a solid material. In distinction to known methods and apparatus, this invention employs a specific fiber-optic bundle configuration, termed a reorganizer, itself known for other uses, for coherently transmitting visible light originating from the scintillation of diffracted x-radiation from the solid material gathered along a substantially one dimensional linear arc, to a two-dimensional photo-sensor array. The two-dimensional photodetector array, with its many closely packed light sensitive pixels, is employed to process the information contained in the diffracted radiation and present the information in the form of a conventional x-ray diffraction spectrum. By this arrangement, the angular range of the combined detector faces may be increased without loss of angular resolution. Further, the prohibitively expensive coupling together of a large number of individual linear diode photodetectors, which would be required to process signals generated by the diffracted radiation, is avoided.

  8. Large angle solid state position sensitive x-ray detector system

    DOE Patents [OSTI]

    Kurtz, D.S.; Ruud, C.O.

    1998-03-03

    A method and apparatus for x-ray measurement of certain properties of a solid material are disclosed. In distinction to known methods and apparatus, this invention employs a specific fiber-optic bundle configuration, termed a reorganizer, itself known for other uses, for coherently transmitting visible light originating from the scintillation of diffracted x-radiation from the solid material gathered along a substantially one dimensional linear arc, to a two-dimensional photo-sensor array. The two-dimensional photodetector array, with its many closely packed light sensitive pixels, is employed to process the information contained in the diffracted radiation and present the information in the form of a conventional x-ray diffraction spectrum. By this arrangement, the angular range of the combined detector faces may be increased without loss of angular resolution. Further, the prohibitively expensive coupling together of a large number of individual linear diode photodetectors, which would be required to process signals generated by the diffracted radiation, is avoided. 7 figs.

  9. Large angle solid state position sensitive x-ray detector system

    DOE Patents [OSTI]

    Kurtz, D.S.; Ruud, C.O.

    1998-07-21

    A method and apparatus are disclosed for x-ray measurement of certain properties of a solid material. In distinction to known methods and apparatus, this invention employs a specific fiber-optic bundle configuration, termed a reorganizer, itself known for other uses, for coherently transmitting visible light originating from the scintillation of diffracted x-radiation from the solid material gathered along a substantially one dimensional linear arc, to a two-dimensional photo-sensor array. The two-dimensional photodetector array, with its many closely packed light sensitive pixels, is employed to process the information contained in the diffracted radiation and present the information in the form of a conventional x-ray diffraction spectrum. By this arrangement, the angular range of the combined detector faces may be increased without loss of angular resolution. Further, the prohibitively expensive coupling together of a large number of individual linear diode photodetectors, which would be required to process signals generated by the diffracted radiation, is avoided. 7 figs.

  10. Diagnostics for the optimization of an 11 keV inverse Compton scattering x-ray source

    SciTech Connect (OSTI)

    Chauchat, A.-S.; Brasile, J.-P; Le Flanchec, V.; Negre, J.-P.; Binet, A.; Ortega, J.-M.

    2013-04-19

    In a scope of a collaboration between Thales Communications and Security and CEA DAM DIF, 11 keV Xrays were produced by inverse Compton scattering on the ELSA facility. In this type of experiment, X-ray observation lies in the use of accurate electron and laser beam interaction diagnostics and on fitted X-ray detectors. The low interaction probability between < 100 {mu}m width, 12 ps [rms] length electron and photon pulses requires careful optimization of pulse spatial and temporal covering. Another issue was to observe 11 keV X-rays in the ambient radioactive noise of the linear accelerator. For that, we use a very sensitive detection scheme based on radio luminescent screens.

  11. Boron phosphide under pressure: In situ study by Raman scattering and X-ray diffraction

    SciTech Connect (OSTI)

    Solozhenko, Vladimir L.; Kurakevych, Oleksandr O.; Le Godec, Yann; Kurnosov, Aleksandr V.; Oganov, Artem R.

    2014-07-21

    Cubic boron phosphide, BP, has been studied in situ by X-ray diffraction and Raman scattering up to 55?GPa at 300?K in a diamond anvil cell. The bulk modulus of B{sub 0}?=?174(2) GPa has been established, which is in excellent agreement with our ab initio calculations. The data on Raman shift as a function of pressure, combined with equation-of-state (EOS) data, allowed us to estimate the Grneisen parameters of the TO and LO modes of zinc-blende structure, ?{sub G}{sup TO?}=?1.26 and ?{sub G}{sup LO?}=?1.13, just like in the case of other A{sup III}B{sup V} diamond-like phases, for which ?{sub G}{sup TO?}>??{sub G}{sup LO?}??1. We also established that the pressure dependence of the effective electro-optical constant ? is responsible for a strong change in relative intensities of the TO and LO modes from I{sub TO}/I{sub LO}???0.25 at 0.1?MPa to I{sub TO}/I{sub LO}???2.5 at 45?GPa, for which we also find excellent agreement between experiment and theory.

  12. Models of the elastic x-ray scattering feature for warm dense aluminum

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Starrett, Charles Edward; Saumon, Didier

    2015-09-03

    The elastic feature of x-ray scattering from warm dense aluminum has recently been measured by Fletcher et al. [Nature Photonics 9, 274 (2015)] with much higher accuracy than had hitherto been possible. This measurement is a direct test of the ionic structure predicted by models of warm dense matter. We use the method of pseudoatom molecular dynamics to predict this elastic feature for warm dense aluminum with temperatures of 1–100 eV and densities of 2.7–8.1g/cm3. We compare these predictions to experiments, finding good agreement with Fletcher et al. and corroborating the discrepancy found in analyses of an earlier experiment ofmore » Ma et al. [Phys. Rev. Lett. 110, 065001 (2013)]. Lastly, we also evaluate the validity of the Thomas-Fermi model of the electrons and of the hypernetted chain approximation in computing the elastic feature and find them both wanting in the regime currently probed by experiments.« less

  13. Models of the elastic x-ray scattering feature for warm dense aluminum

    SciTech Connect (OSTI)

    Starrett, Charles Edward; Saumon, Didier

    2015-09-03

    The elastic feature of x-ray scattering from warm dense aluminum has recently been measured by Fletcher et al. [Nature Photonics 9, 274 (2015)] with much higher accuracy than had hitherto been possible. This measurement is a direct test of the ionic structure predicted by models of warm dense matter. We use the method of pseudoatom molecular dynamics to predict this elastic feature for warm dense aluminum with temperatures of 1–100 eV and densities of 2.7–8.1g/cm3. We compare these predictions to experiments, finding good agreement with Fletcher et al. and corroborating the discrepancy found in analyses of an earlier experiment of Ma et al. [Phys. Rev. Lett. 110, 065001 (2013)]. Lastly, we also evaluate the validity of the Thomas-Fermi model of the electrons and of the hypernetted chain approximation in computing the elastic feature and find them both wanting in the regime currently probed by experiments.

  14. Raman and fluorescence characteristics of resonant inelastic X-ray scattering from doped superconducting cuprates

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Huang, H. Y.; Jia, C. J.; Chen, Z. Y.; Wohlfeld, K.; Moritz, B.; Devereaux, T. P.; Wu, W. B.; Okamoto, J.; Lee, W. S.; Hashimoto, M.; et al

    2016-01-22

    Measurements of spin excitations are essential for an understanding of spin-mediated pairing for superconductivity; and resonant inelastic X-ray scattering (RIXS) provides a considerable opportunity to probe high-energy spin excitations. However, whether RIXS correctly measures the collective spin excitations of doped superconducting cuprates remains under debate. Here we demonstrate distinct Raman- and fluorescence-like RIXS excitations of Bi1.5Pb0.6Sr1.54CaCu2O8+δ. Combining photon-energy and momentum dependent RIXS measurements with theoretical calculations using exact diagonalization provides conclusive evidence that the Raman-like RIXS excitations correspond to collective spin excitations, which are magnons in the undoped Mott insulators and evolve into paramagnons in doped superconducting compounds. In contrast,more » the fluorescence-like shifts are due primarily to the continuum of particle-hole excitations in the charge channel. Our results show that under the proper experimental conditions RIXS indeed can be used to probe paramagnons in doped high-Tc cuprate superconductors.« less

  15. SSRL School 2008 on Hard X-ray Scattering Techniques in MES

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    May 20-22, 2008 SSRL School on Synchrotron X-ray Absorption Spectroscopy Techniques in Environmental and Materials Sciences: Theory and Application Group photo from the 2008 SSRL...

  16. Biological Imaging by Soft X-Ray Diffraction Microscopy

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    and angles of x rays scattered from the sample rather than transmitted through it). Shapiro et al. have now chimed in with the first lensless imaging of a sample as complex as a...

  17. Commissioning of a Soft X-ray Beamline PF-BL-16A with a Variable-Included-Angle Varied-Line-Spacing Grating Monochromator

    SciTech Connect (OSTI)

    Amemiya, Kenta; Toyoshima, Akio; Kikuchi, Takashi; Kosuge, Takashi; Nigorikawa, Kazuyuki; Sumii, Ryohei; Ito, Kenji

    2010-06-23

    The design and commissioning of a new soft X-ray beamline, BL-16A, at the Photon Factory is presented. The beamline consists of a pre-focusing mirror, an entrance slit, a variable-included-angle varied-line-spacing plane grating monochromator, and a post-focusing system as usual, and provides circularly and linearly polarized soft X rays in the energy range 200-1500 eV with an APPLE-II type undulator. The commissioning procedure for the beamline optics is described in detail, especially the check of the focal position for the zero-th order and diffracted X rays.

  18. Realizing in-plane surface diffraction by x-ray multiple-beam diffraction with large incidence angle

    SciTech Connect (OSTI)

    Huang, Xian-Rong Gog, Thomas; Assoufid, Lahsen; Peng, Ru-Wen; Siddons, D. P.

    2014-11-03

    Based on rigorous dynamical-theory calculations, we demonstrate the principle of an x-ray multiple-beam diffraction (MBD) scheme that overcomes the long-lasting difficulties of high-resolution in-plane diffraction from crystal surfaces. This scheme only utilizes symmetric reflection geometry with large incident angles but activates the out-of-plane and in-plane diffraction processes simultaneously and separately in the continuous MBD planes. The in-plane diffraction is realized by detoured MBD, where the intermediate diffracted waves propagate parallel to the surface, which corresponds to an absolute Bragg surface diffraction configuration that is extremely sensitive to surface structures. A series of MBD diffraction and imaging techniques may be developed from this principle to study surface/interface (misfit) strains, lateral nanostructures, and phase transitions of a wide range of (pseudo)cubic crystal structures, including ultrathin epitaxial films and multilayers, quantum dots, strain-engineered semiconductor or (multi)ferroic materials, etc.

  19. Phase-based x-ray scatteringA possible method to detect cancer cells in a very early stage

    SciTech Connect (OSTI)

    Feye-Treimer, U. Treimer, W.

    2014-05-15

    Purpose: This theoretical work contains a detailed investigation of the potential and sensitivity of phase-based x-ray scattering for cancer detection in biopsies if cancer is in a very early stage of development. Methods: Cancer cells in their early stage of development differ from healthy ones mainly due to their faster growing cell nuclei and the enlargement of their densities. This growth is accompanied by an altered nucleusplasma relation for the benefit of the cell nuclei, that changes the physical properties especially the index of refraction of the cell and the one of the cell nuclei. Interaction of radiation with matter is known to be highly sensitive to small changes of the index of refraction of matter; therefore a detection of such changes of volume and density of cell nuclei by means of high angular resolved phase-based scattering of x rays might provide a technique to distinguish malignant cells from healthy ones ifthe cellcell nucleus system is considered as a coherent phase shifting object. Then one can observe from a thin biopsy which represents a monolayer of cells (no multiple scattering) that phase-based x-ray scattering curves from healthy cells differ from those of cancer cells in their early stage of development. Results: Detailed calculations of x-ray scattering patterns from healthy and cancer cell nuclei yield graphs and numbers with which one can distinguish healthy cells from cancer ones, taking into account that both kinds of cells occur in a tissue within a range of size and density. One important result is the role and the influence of the (lateral) coherence width of the radiation on the scattering curves and the sensitivity of phase-based scattering for cancer detection. A major result is that a larger coherence width yields a larger sensitivity for cancer detection. Further import results are calculated limits for critical sizes and densities of cell nuclei in order to attribute the investigated tissue to be healthy or diseased

  20. Simulations of Microchannel Plate Sensitivity to <20 keV X-rays as a Function of Energy and Incident Angle

    SciTech Connect (OSTI)

    Kruschwitz, Craig; Wu, M.; Rochau, G. A.

    2013-06-13

    We present results of Monte Carlo simulations of microchannel plate (MCP) response to x-rays in the 250 eV to 20 keV energy range as a function of both x-ray energy and impact angle. The model is based on the model presented in Rochau et al. (2006). However, while the Rochau et al. (2006) model was two-dimensional, and their results only went to 5 keV, our results have been expanded to 20 keV, and our model has been incorporated into a three-dimensional Monte Carlo MCP model that we have developed over the past several years (Kruschwitz et al. 2011). X-ray penetration through multiple MCP pore walls is increasingly important above 5 keV. The effect of x-ray penetration through multiple pores on MCP performance was studied and is presented.

  1. Probing single magnon excitations in Sr₂IrO₄ using O K-edge resonant inelastic x-ray scattering

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Liu, X.; Dean, M. P. M.; Liu, J.; Chiuzbaian, S. G.; Jaouen, N.; Nicolaou, A.; Yin, W. G.; Rayan Serrao, C.; Ramesh, R.; Ding, H.; et al

    2015-04-28

    Resonant inelastic X-ray scattering (RIXS) at the L-edge of transition metal elements is now commonly used to probe single magnon excitations. Here we show that single magnon excitations can also be measured with RIXS at the K-edge of the surrounding ligand atoms when the center heavy metal elements have strong spin-orbit coupling. This is demonstrated with oxygen K-edge RIXS experiments on the perovskite Sr₂IrO₄, where low energy peaks from single magnon excitations were observed. This new application of RIXS has excellent potential to be applied to a wide range of magnetic systems based on heavy elements, for which the L-edgemore » RIXS energy resolutions in the hard X-ray region is usually poor.« less

  2. Probing single magnon excitations in Sr₂IrO₄ using O K-edge resonant inelastic x-ray scattering

    SciTech Connect (OSTI)

    Liu, X.; Dean, M. P. M.; Liu, J.; Chiuzbaian, S. G.; Jaouen, N.; Nicolaou, A.; Yin, W. G.; Rayan Serrao, C.; Ramesh, R.; Ding, H.; Hill, J. P.

    2015-04-28

    Resonant inelastic X-ray scattering (RIXS) at the L-edge of transition metal elements is now commonly used to probe single magnon excitations. Here we show that single magnon excitations can also be measured with RIXS at the K-edge of the surrounding ligand atoms when the center heavy metal elements have strong spin-orbit coupling. This is demonstrated with oxygen K-edge RIXS experiments on the perovskite Sr₂IrO₄, where low energy peaks from single magnon excitations were observed. This new application of RIXS has excellent potential to be applied to a wide range of magnetic systems based on heavy elements, for which the L-edge RIXS energy resolutions in the hard X-ray region is usually poor.

  3. Experimental methods in the study of neutron scattering at small angles

    SciTech Connect (OSTI)

    Dragolici, Cristian A.

    2014-11-24

    Small angle scattering (SAS) is the collective name given to the techniques of small angle neutron (SANS) and X-ray (SAXS) scattering. They offer the possibility to analyze particles without disturbing their natural environment. In each of these techniques radiation is elastically scattered by a sample and the resulting scattering pattern is analyzed to provide information about the size, shape and orientation of some component of the sample. Accordingly, a large number of methods and experimental patterns have been developed to ease the investigation of condensed matter by use of these techniques. Some of them are the discussed in this paper.

  4. BioSAXS Sample Changer: a robotic sample changer for rapid and reliable high-throughput X-ray solution scattering experiments

    SciTech Connect (OSTI)

    Round, Adam, E-mail: around@embl.fr; Felisaz, Franck [European Molecular Biology Laboratory, Grenoble Outstation, 71 Avenue des Martyrs, CS 90181, 38042 Grenoble (France); Universit Grenoble AlpesEMBLCNRS, 71 Avenue des Martyrs, CS 90181, 38042 Grenoble (France); Fodinger, Lukas; Gobbo, Alexandre [European Molecular Biology Laboratory, Grenoble Outstation, 71 Avenue des Martyrs, CS 90181, 38042 Grenoble (France); Huet, Julien [European Molecular Biology Laboratory, Grenoble Outstation, 71 Avenue des Martyrs, CS 90181, 38042 Grenoble (France); Universit Grenoble AlpesEMBLCNRS, 71 Avenue des Martyrs, CS 90181, 38042 Grenoble (France); Villard, Cyril [European Molecular Biology Laboratory, Grenoble Outstation, 71 Avenue des Martyrs, CS 90181, 38042 Grenoble (France); Blanchet, Clement E., E-mail: around@embl.fr [EMBL c/o DESY, Notkestrasse 85, 22603 Hamburg (Germany); Pernot, Petra; McSweeney, Sean [ESRF, 6 Rue Jules Horowitz, 38000 Grenoble (France); Roessle, Manfred; Svergun, Dmitri I. [EMBL c/o DESY, Notkestrasse 85, 22603 Hamburg (Germany); Cipriani, Florent, E-mail: around@embl.fr [European Molecular Biology Laboratory, Grenoble Outstation, 71 Avenue des Martyrs, CS 90181, 38042 Grenoble (France); Universit Grenoble AlpesEMBLCNRS, 71 Avenue des Martyrs, CS 90181, 38042 Grenoble (France)

    2015-01-01

    A robotic sample changer for solution X-ray scattering experiments optimized for speed and to use the minimum amount of material has been developed. This system is now in routine use at three high-brilliance European synchrotron sites, each capable of several hundred measurements per day. Small-angle X-ray scattering (SAXS) of macromolecules in solution is in increasing demand by an ever more diverse research community, both academic and industrial. To better serve user needs, and to allow automated and high-throughput operation, a sample changer (BioSAXS Sample Changer) that is able to perform unattended measurements of up to several hundred samples per day has been developed. The Sample Changer is able to handle and expose sample volumes of down to 5 l with a measurement/cleaning cycle of under 1 min. The samples are stored in standard 96-well plates and the data are collected in a vacuum-mounted capillary with automated positioning of the solution in the X-ray beam. Fast and efficient capillary cleaning avoids cross-contamination and ensures reproducibility of the measurements. Independent temperature control for the well storage and for the measurement capillary allows the samples to be kept cool while still collecting data at physiological temperatures. The Sample Changer has been installed at three major third-generation synchrotrons: on the BM29 beamline at the European Synchrotron Radiation Facility (ESRF), the P12 beamline at the PETRA-III synchrotron (EMBL@PETRA-III) and the I22/B21 beamlines at Diamond Light Source, with the latter being the first commercial unit supplied by Bruker ASC.

  5. Bent crystal spectrometer for both frequency and wavenumber resolved x-ray scattering at a seeded free-electron laser

    SciTech Connect (OSTI)

    Zastrau, Ulf; Fletcher, Luke B.; Galtier, Eric Ch.; Gamboa, Eliseo; Glenzer, Siegfried H.; Heimann, Philipp; Nagler, Bob; Schropp, Andreas; Lee, Hae Ja; Frster, Eckhart; Marschner, Heike; Wehrhan, Ortrud

    2014-09-15

    We present a cylindrically curved GaAs x-ray spectrometer with energy resolution ?E/E = 1.1 ?10{sup ?4} and wave-number resolution of ?k/k = 3 ?10{sup ?3}, allowing plasmon scattering at the resolution limits of the Linac Coherent Light Source (LCLS) x-ray free-electron laser. It spans scattering wavenumbers of 3.6 to 5.2/ in 100 separate bins, with only 0.34% wavenumber blurring. The dispersion of 0.418 eV/13.5??m agrees with predictions within 1.3%. The reflection homogeneity over the entire wavenumber range was measured and used to normalize the amplitude of scattering spectra. The proposed spectrometer is superior to a mosaic highly annealed pyrolytic graphite spectrometer when the energy resolution needs to be comparable to the LCLS seeded bandwidth of 1 eV and a significant range of wavenumbers must be covered in one exposure.

  6. Resonant inelastic X-ray scattering spectrometer with 25meV resolution at the Cu K -edge

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Ketenoglu, Didem; Harder, Manuel; Klementiev, Konstantin; Upton, Mary; Taherkhani, Mehran; Spiwek, Manfred; Dill, Frank-Uwe; Wille, Hans-Christian; Yavaş, Hasan

    2015-06-27

    An unparalleled resolution is reported with an inelastic X-ray scattering instrument at the CuK-edge. Based on a segmented concave analyzer, featuring single-crystal quartz (SiO2) pixels, the spectrometer delivers a resolution near 25meV (FWHM) at 8981eV. Besides the quartz analyzer, the performance of the spectrometer relies on a four-bounce Si(553) high-resolution monochromator and focusing Kirkpatrick–Baez optics. The measured resolution agrees with the ray-tracing simulation of an ideal spectrometer. The performance of the spectrometer is demonstrated by reproducing the phonon dispersion curve of a beryllium single-crystal.

  7. Focus characterization at an X-ray free-electron laser by coherent scattering and speckle analysis

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Sikorski, Marcin; Song, Sanghoon; Schropp, Andreas; Deutsches Elektronen-Synchrotron, Hamburg; Seiboth, Frank; Feng, Yiping; Alonso-Mori, Roberto; Chollet, Matthieu; Lemke, Henrik T.; Sokaras, Dimosthenis; et al

    2015-04-14

    X-ray focus optimization and characterization based on coherent scattering and quantitative speckle size measurements was demonstrated at the Linac Coherent Light Source. Its performance as a single-pulse free-electron laser beam diagnostic was tested for two typical focusing configurations. The results derived from the speckle size/shape analysis show the effectiveness of this technique in finding the focus' location, size and shape. In addition, its single-pulse compatibility enables users to capture pulse-to-pulse fluctuations in focus properties compared with other techniques that require scanning and averaging.

  8. The Investigation of Decomposition of Supersaturated Si Solid Solution by X-Ray Diffuse Scattering

    SciTech Connect (OSTI)

    Shcherbachev, Kirill; Privezentsev, Vladimir

    2010-04-06

    The results of investigation of microstructure of Zn doped n-type Si by X-ray Diffuse Scattering (XRDS) are presented. Experimental samples were made by a high-temperature Zn diffusion annealing with subsequent quenching and tempering. Reciprocal space maps of XRDS were obtained. They resulted in that crystal lattice of the samples contains spherical MDs of vacancy type and plane shape MDs of interstitial type. The MDs average radius and their type depend on Zn doping level and thermal treatment after Zn diffusion.

  9. X-ray absorption and resonant inelastic x-ray scattering (RIXS) show the presence of Cr{sup +} at the surface and in the bulk of CrF{sub 2}

    SciTech Connect (OSTI)

    Jiménez-Mier, J.; Olalde-Velasco, P.; Yang, W.-L.; Denlinger, J.

    2015-07-23

    X-Ray absorption and resonant inelastic x-ray scattering (RIXS) spectra of CrF{sub 2} recorded at the chromium L{sub 2,3} are presented. An atomic multiplet crystal field calculation is compared with the experimental data. Experiment and theory are in agreement once the calculation includes three chromium oxidation states, namely Cr{sup +}, Cr{sup 2+}, and Cr{sup 3+}. X-Ray absorption allows a direct determination of the surface oxidation, while the RIXS spectra shows the presence of these three oxidation states in the sample bulk. To give a quantitative interpretation of the RIXS data the effect of the incomming and outgoing photon penetration depth and self-absorption must be considered. For the much simpler case of MnF{sub 2}, with only one metal oxidation state, the measured RIXS spectra relative intensities are found to be proportional to the square of the sample attenuation length.

  10. Polarization periodicity in the B1 columnar phase determined by resonant x-ray scattering

    SciTech Connect (OSTI)

    Folcia, C.L.; Pindak, R.; Ortega, J.; Etxebarria, J.; Pan, L.; Wang, S.; Huang, C.C.; Ponsinet, V.; Barois, P. and Gimeno, N.

    2011-07-14

    We report structural results that evidence the polarization distribution of the blocks in the columnar phase of an achiral bent-core liquid crystal. The study was performed using resonant x-ray diffraction at the sulfur K edge on oriented samples aligned on substrates. The extra periodicity is revealed through the violation of the systematic extinction rule of the structural symmetry group along the experimentally accessible diffraction direction. Further data obtained from the polarization analysis of a resonant reflection give information concerning the transition mechanism between B{sub 1} and B{sub 2} phases.

  11. Polarization Periodicity in the B(1) Columnar Phase Determined by Resonant X-ray Scattering

    SciTech Connect (OSTI)

    C Folcia; J Ortega; J Etxebarria; L Pan; S Wang; C Huang; V Ponsinet; P Barois; R Pindak; N Gimeno

    2011-12-31

    We report structural results that evidence the polarization distribution of the blocks in the columnar phase of an achiral bent-core liquid crystal. The study was performed using resonant x-ray diffraction at the sulfur K edge on oriented samples aligned on substrates. The extra periodicity is revealed through the violation of the systematic extinction rule of the structural symmetry group along the experimentally accessible diffraction direction. Further data obtained from the polarization analysis of a resonant reflection give information concerning the transition mechanism between B{sub 1} and B{sub 2} phases.

  12. Tunable X-ray source

    DOE Patents [OSTI]

    Boyce, James R.

    2011-02-08

    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.

  13. Ultrabright x-ray laser scattering for dynamic warm dense matter physics

    SciTech Connect (OSTI)

    Fletcher, L. B.; Lee, H. J.; Doppner, T.; Galtier, E.; Nagler, B.; Heimann, P.; Fortmann, C.; Mao, T.; Millot, M.; Pak, A.; Turnbull, D.; Chapman, D. A.; Gericke, D. O.; Vorberger, J.; White, T.; Gregori, G.; Wei, M.; Barbrel, B.; Falcone, R. W.; Kao, C. -C.; Nuhn, H.; Welch, J.; Zastrau, U.; Neumayer, P.; Hastings, J. B.; Glenzer, S. H.

    2015-03-23

    In megabar shock waves, materials compress and undergo a phase transition to a dense charged-particle system that is dominated by strong correlations and quantum effects. This complex state, known as warm dense matter, exists in planetary interiors and many laboratory experiments (for example, during high-power laser interactions with solids or the compression phase of inertial confinement fusion implosions). Here, we apply record peak brightness X-rays at the Linac Coherent Light Source to resolve ionic interactions at atomic (ångström) scale lengths and to determine their physical properties. Our in situ measurements characterize the compressed lattice and resolve the transition to warm dense matter, demonstrating that short-range repulsion between ions must be accounted for to obtain accurate structure factor and equation of state data. Additionally, the unique properties of the X-ray laser provide plasmon spectra that yield the temperature and density with unprecedented precision at micrometre-scale resolution in dynamic compression experiments.

  14. A general framework and review of scatter correction methods in x-ray cone-beam computerized tomography. Part 1: Scatter compensation approaches

    SciTech Connect (OSTI)

    Ruehrnschopf, Ernst-Peter; Klingenbeck, Klaus

    2011-07-15

    Since scattered radiation in cone-beam volume CT implies severe degradation of CT images by quantification errors, artifacts, and noise increase, scatter suppression is one of the main issues related to image quality in CBCT imaging. The aim of this review is to structurize the variety of scatter suppression methods, to analyze the common structure, and to develop a general framework for scatter correction procedures. In general, scatter suppression combines hardware techniques of scatter rejection and software methods of scatter correction. The authors emphasize that scatter correction procedures consist of the main components scatter estimation (by measurement or mathematical modeling) and scatter compensation (deterministic or statistical methods). The framework comprises most scatter correction approaches and its validity also goes beyond transmission CT. Before the advent of cone-beam CT, a lot of papers on scatter correction approaches in x-ray radiography, mammography, emission tomography, and in Megavolt CT had been published. The opportunity to avail from research in those other fields of medical imaging has not yet been sufficiently exploited. Therefore additional references are included when ever it seems pertinent. Scatter estimation and scatter compensation are typically intertwined in iterative procedures. It makes sense to recognize iterative approaches in the light of the concept of self-consistency. The importance of incorporating scatter compensation approaches into a statistical framework for noise minimization has to be underscored. Signal and noise propagation analysis is presented. A main result is the preservation of differential-signal-to-noise-ratio (dSNR) in CT projection data by ideal scatter correction. The objective of scatter compensation methods is the restoration of quantitative accuracy and a balance between low-contrast restoration and noise reduction. In a synopsis section, the different deterministic and statistical methods are

  15. SSRL School 2007 on Hard X-ray Scattering: Techniques in MES

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    peak intensities, A. Vailionis SAXS, J. Pople Tuesday Afternoon, Bulk-Structure Techniques Structure characterization, A. Mehta In-situ scattering, S. Webb Amorphous...

  16. Direct comparisons of X-ray scattering and atomistic molecular dynamics simulations for precise acid copolymers and ionomers

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Buitrago, C. Francisco; Bolintineanu, Dan; Seitz, Michelle E.; Opper, Kathleen L.; Wagener, Kenneth B.; Stevens, Mark J.; Frischknecht, Amalie Lucile; Winey, Karen I.

    2015-02-09

    Designing acid- and ion-containing polymers for optimal proton, ion, or water transport would benefit profoundly from predictive models or theories that relate polymer structures with ionomer morphologies. Recently, atomistic molecular dynamics (MD) simulations were performed to study the morphologies of precise poly(ethylene-co-acrylic acid) copolymer and ionomer melts. Here, we present the first direct comparisons between scattering profiles, I(q), calculated from these atomistic MD simulations and experimental X-ray data for 11 materials. This set of precise polymers has spacers of exactly 9, 15, or 21 carbons between acid groups and has been partially neutralized with Li, Na, Cs, or Zn. Inmore » these polymers, the simulations at 120 °C reveal ionic aggregates with a range of morphologies, from compact, isolated aggregates (type 1) to branched, stringy aggregates (type 2) to branched, stringy aggregates that percolate through the simulation box (type 3). Excellent agreement is found between the simulated and experimental scattering peak positions across all polymer types and aggregate morphologies. The shape of the amorphous halo in the simulated I(q) profile is in excellent agreement with experimental I(q). We found that the modified hard-sphere scattering model fits both the simulation and experimental I(q) data for type 1 aggregate morphologies, and the aggregate sizes and separations are in agreement. Given the stringy structure in types 2 and 3, we develop a scattering model based on cylindrical aggregates. Both the spherical and cylindrical scattering models fit I(q) data from the polymers with type 2 and 3 aggregates equally well, and the extracted aggregate radii and inter- and intra-aggregate spacings are in agreement between simulation and experiment. Furthermore, these dimensions are consistent with real-space analyses of the atomistic MD simulations. By combining simulations and experiments, the ionomer scattering peak can be associated with the

  17. Silicon nanocrystals with high boron and phosphorus concentration hydrophilic shell—Raman scattering and X-ray photoelectron spectroscopic studies

    SciTech Connect (OSTI)

    Fujii, Minoru Sugimoto, Hiroshi; Hasegawa, Masataka; Imakita, Kenji

    2014-02-28

    Boron (B) and phosphorus (P) codoped silicon (Si) nanocrystals, which exhibit very wide range tunable luminescence due to the donor to acceptor transitions and can be dispersed in polar liquids without organic ligands, are studied by Raman scattering and X-ray photoelectron spectroscopies. Codoped Si nanocrystals exhibit a Raman spectrum significantly different from those of intrinsic ones. First, the Raman peak energy is almost insensitive to the size and is very close to that of bulk Si crystal in the diameter range of 2.7 to 14 nm. Second, the peak is much broader than that of intrinsic ones. Furthermore, an additional broad peak, the intensity of which is about 20% of the main peak, appears around 650 cm{sup −1}. The peak can be assigned to local vibrational modes of substitutional B and B-P pairs, B clusters, B-interstitial clusters, etc. in Si crystal. The Raman and X-ray photoelectron spectroscopic studies suggest that a crystalline shell heavily doped with these species is formed at the surface of a codoped Si nanocrystal and it induces the specific properties, i.e., hydrophilicity, high-stability in water, high resistance to hydrofluoric acid, etc.

  18. Demonstration of space-resolved x-ray Thomson scattering capability for warm dense matter experiments on the Z accelerator

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Ao, T.; Harding, E. C.; Bailey, J. E.; Lemke, R. W.; Desjarlais, M. P.; Hansen, S. B.; Smith, I. C.; Geissel, M.; Maurer, A.; Reneker, J.; et al

    2016-01-13

    Experiments on the Sandia Z pulsed-power accelerator demonstrated the ability to produce warm dense matter (WDM) states with unprecedented uniformity, duration, and size, which are ideal for investigations of fundamental WDM properties. For the first time, space-resolved x-ray Thomson scattering (XRTS) spectra from shocked carbon foams were recorded on Z. The large (> 20 MA) electrical current produced by Z was used to launch Al flyer plates up to 25 km/s. The impact of the flyer plate on a CH2 foam target produced a shocked state with an estimated pressure of 0.75 Mbar, density of 0.52 g/cm3, and temperature ofmore » 4.3 eV. Both unshocked and shocked portions of the foam target were probed with 6.2 keV x-rays produced by focusing the Z-Beamlet laser onto a nearby Mn foil. The data is composed of three spatially distinct spectra that were simultaneously captured with a single spectrometer with high spectral (4.8 eV) and spatial (190 μm) resolutions. Furthermore, these spectra provide detailed information on three target locations: the laser spot, the unshocked foam, and the shocked foam.« less

  19. Conformational dynamics of a crystalline protein from microsecond-scale molecular dynamics simulations and diffuse X-ray scattering

    SciTech Connect (OSTI)

    Wall, Michael E.; Van Benschoten, Andrew H.; Sauter, Nicholas K.; Adams, Paul D.; Fraser, James S.; Terwilliger, Thomas C.

    2014-12-01

    X-ray diffraction from protein crystals includes both sharply peaked Bragg reflections and diffuse intensity between the peaks. The information in Bragg scattering is limited to what is available in the mean electron density. The diffuse scattering arises from correlations in the electron density variations and therefore contains information about collective motions in proteins. Previous studies using molecular-dynamics (MD) simulations to model diffuse scattering have been hindered by insufficient sampling of the conformational ensemble. To overcome this issue, we have performed a 1.1-?s MD simulation of crystalline staphylococcal nuclease, providing 100-fold more sampling than previous studies. This simulation enables reproducible calculations of the diffuse intensity and predicts functionally important motions, including transitions among at least eight metastable states with different active-site geometries. The total diffuse intensity calculated using the MD model is highly correlated with the experimental data. In particular, there is excellent agreement for the isotropic component of the diffuse intensity, and substantial but weaker agreement for the anisotropic component. The decomposition of the MD model into protein and solvent components indicates that proteinsolvent interactions contribute substantially to the overall diffuse intensity. In conclusion, diffuse scattering can be used to validate predictions from MD simulations and can provide information to improve MD models of protein motions.

  20. Conformational dynamics of a crystalline protein from microsecond-scale molecular dynamics simulations and diffuse X-ray scattering

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Wall, Michael E.; Van Benschoten, Andrew H.; Sauter, Nicholas K.; Adams, Paul D.; Fraser, James S.; Terwilliger, Thomas C.

    2014-12-01

    X-ray diffraction from protein crystals includes both sharply peaked Bragg reflections and diffuse intensity between the peaks. The information in Bragg scattering is limited to what is available in the mean electron density. The diffuse scattering arises from correlations in the electron density variations and therefore contains information about collective motions in proteins. Previous studies using molecular-dynamics (MD) simulations to model diffuse scattering have been hindered by insufficient sampling of the conformational ensemble. To overcome this issue, we have performed a 1.1-μs MD simulation of crystalline staphylococcal nuclease, providing 100-fold more sampling than previous studies. This simulation enables reproducible calculationsmore » of the diffuse intensity and predicts functionally important motions, including transitions among at least eight metastable states with different active-site geometries. The total diffuse intensity calculated using the MD model is highly correlated with the experimental data. In particular, there is excellent agreement for the isotropic component of the diffuse intensity, and substantial but weaker agreement for the anisotropic component. The decomposition of the MD model into protein and solvent components indicates that protein–solvent interactions contribute substantially to the overall diffuse intensity. In conclusion, diffuse scattering can be used to validate predictions from MD simulations and can provide information to improve MD models of protein motions.« less

  1. Electron-electron correlations in fullerene C{sub 60} probed by incoherent scattering of x rays

    SciTech Connect (OSTI)

    Petrillo, C.; Sacchetti, F.; Orecchini, A.; De Renzi, R.; Ricco, M.

    2006-08-15

    The static structure factor of electrons in fullerene has been obtained by a properly designed x-ray diffraction experiment. Due to the intense diffuse scattering caused by the orientational disorder of the C{sub 60} molecules in fullerene, the experiment presented several difficulties. Nonetheless, the data were accurate enough to provide an estimate of the exchange-correlation energy and to make a valuable comparison of the static structure factors of fullerene and diamond. The observed value of the exchange-correlation energy, which is larger in fullerene than in diamond, suggests a clear link between carbon polymorphism and dynamic electron correlations. The experimental data of static structure factor of fullerene, together with the derived exchange-correlation contribution to the cohesion and the pair-correlation function, offer an interesting test on the validity of the local-density treatment of the electron correlations in solids.

  2. Inelastic X-ray Scattering Investigations of Lattice Dynamics in SmFeAsO1-xFy Superconductors

    SciTech Connect (OSTI)

    Hill, J.P.; Le Tacon, M.; Forrest, T.R.; Ruegg, Ch.; Bosak, A.; Noffsinger, J.; Walters, A.C.; Toulemonde, P.; Palenzona, A.; Zhigadlo, N.D.; Karpinski, J.; Krisch, M.; McMorrow, D.F.

    2010-05-23

    We report measurements of the phonon density of states as measured with inelastic x-ray scattering in SmFeAsO{sub 1-x}F{sub y} powders. An unexpected strong renormalization of phonon branches around 23 meV is observed as fluorine is substituted for oxygen. Phonon dispersion measurements on SmFeAsO{sub 1-x}F{sub y} single crystals allow us to identify the 21 meV A{sub 1g} in-phase (Sm,As) and the 26 meV B{sub 1g} (Fe,O) modes to be responsible for this renormalization, and may reaveal unusual electron-phonon coupling through the spin channel in iron-based superconductors.

  3. Theoretical approach to resonant inelastic x-ray scattering in iron-based superconductors at the energy scale of the superconducting gap

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Marra, Pasquale; van den Brink, Jeroen; Sykora, Steffen

    2016-05-06

    Here, we develop a phenomenological theory to predict the characteristic features of the momentumdependent scattering amplitude in resonant inelastic x-ray scattering (RIXS) at the energy scale of the superconducting gap in iron-based super-conductors. Taking into account all relevant orbital states as well as their specific content along the Fermi surface we evaluate the charge and spin dynamical structure factors for the compounds LaOFeAs and LiFeAs, based on tight-binding models which are fully consistent with recent angle-resolved photoemission spectroscopy (ARPES) data. We find a characteristic intensity redistribution between charge and spin dynamical structure factors which discriminates between sign-reversing and sign-preserving quasiparticlemore » excitations. Consequently, our results show that RIXS spectra can distinguish between s± and s++ wave gap functions in the singlet pairing case. In addition, we find that an analogous intensity redistribution at small momenta can reveal the presence of a chiral p-wave triplet pairing.« less

  4. Investigation of chromophore-chromophore interaction by electro-optic measurements, linear dichroism, x-ray scattering, and density-functional calculations

    SciTech Connect (OSTI)

    Apitz, D.; Bertram, R.P.; Benter, N.; Buse, K.; Hieringer, W.; Andreasen, J.W.; Nielsen, M.M.; Johansen, P.M.

    2005-09-01

    Free-beam interferometry and angle-resolved absorption spectra are used to investigate the linear electro-optic coefficients and the linear dichroism in photoaddressable bis-azo copolymer thin films. From the first- and second order parameters deduced, the chromophore orientation distribution is calculated and displayed for several poling temperatures and chromophore concentrations. The influence of dipole-dipole interaction on the overall polymer dynamics is discussed. The first order parameter, and therefore the Pockels effect, peaks for a poling temperature of around 10 deg. C above the glass transition. The decrease of the Pockels effect above this temperature region is triggered by a head-to-tail chromophore orientation, i.e., a transition to a microcrystalline phase, increasing the second order parameter. Comparison of the experimentally observed absorption spectra and those obtained by density-functional calculations support the picture of differently aligned bis-azo dye molecules in a trans,trans configuration. Complementary wide-angle x-ray scattering is recorded to confirm the various kinds of ordering in samples poled at different temperatures.

  5. Electronic and magnetic properties of manganite thin films with different compositions and its correlation with transport properties: An X-ray resonant magnetic scattering study

    SciTech Connect (OSTI)

    Singh, Surendra; Freeland, J. W.; Fitzsimmons, M. R.; Jeen, H.; Biswas, A.

    2014-12-14

    Here, we present x-ray resonant magnetic dichroism and x-ray resonant magnetic scattering measurements of the temperature dependence of magnetism in Pr-doped La-Ca-Mn-O films grown on (110) NdGaO{sub 3} substrates. We observed thermal hysteresis of the ferromagnetism in one film that also showed large thermal hysteresis of ?18?K in transport measurements. While in a second film of a different nominal chemistry, which showed very small thermal hysteresis ?3?K in transport measurements, no thermal hysteresis of the ferromagnetism was observed. These macroscopic properties are correlated with evolution of surface magnetization across metal insulator transition for these films as observed by soft x-ray resonant magnetic scattering measurements.

  6. Electronic and magnetic properties of manganite thin films with different compositions and its correlation with transport properties: An X-ray resonant magnetic scattering study

    SciTech Connect (OSTI)

    Singh, Surendra; Freeland, J. W.; Fitzsimmons, M. R.; Jeen, H.; Biswas, A.

    2014-12-08

    Here, we present x-ray resonant magnetic dichroism and x-ray resonant magnetic scattering measurements of the temperature dependence of magnetism in Pr-doped La-Ca-Mn-O films grown on (110) NdGaO3 substrates. We observed thermal hysteresis of the ferromagnetism in one film that also showed large thermal hysteresis of ~18K in transport measurements. While in a second film of a different nominal chemistry, which showed very small thermal hysteresis ~3K in transport measurements, no thermal hysteresis of the ferromagnetism was observed. As a result, these macroscopic properties are correlated with evolution of surface magnetization across metal insulator transition for these films as observed by soft x-ray resonant magnetic scattering measurements.

  7. Electronic and magnetic properties of manganite thin films with different compositions and its correlation with transport properties: An X-ray resonant magnetic scattering study

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Singh, Surendra; Freeland, J. W.; Fitzsimmons, M. R.; Jeen, H.; Biswas, A.

    2014-12-08

    Here, we present x-ray resonant magnetic dichroism and x-ray resonant magnetic scattering measurements of the temperature dependence of magnetism in Pr-doped La-Ca-Mn-O films grown on (110) NdGaO3 substrates. We observed thermal hysteresis of the ferromagnetism in one film that also showed large thermal hysteresis of ~18K in transport measurements. While in a second film of a different nominal chemistry, which showed very small thermal hysteresis ~3K in transport measurements, no thermal hysteresis of the ferromagnetism was observed. As a result, these macroscopic properties are correlated with evolution of surface magnetization across metal insulator transition for these films as observed bymore » soft x-ray resonant magnetic scattering measurements.« less

  8. Pressure-induced valence change in YbAl3: a combined high pressure inelastic x-ray scattering and theoretical investigation

    SciTech Connect (OSTI)

    Bauer, E D; Kumar, R S; Svane, A; Vaitheeswaran, G; Nicol, M F; Kanchana, V; Hu, M; Cornelius, A L

    2008-01-01

    High resolution x-ray absorption (XAS) experiments in the partial fluorescence yield mode (PFY) and resonant inelastic x-ray emission (RXES) measurements under pressure were performed on the intermediate valence compound YbAl{sub 3} up to 38 GPa. The results of the Yb L{sub 3} PFY-XAS and RXES studies show a smooth valence increase in YbAl{sub 3} from 2.75 to 2.93 at ambient to 38 GPa. In-situ angle dispersive synchrotron high pressure x-ray diffraction experiments carried out using a diamond cell at room temperature to study the equation of state showed the ambient cubic phase stable up to 40 GPa. The results obtained from self-interaction corrected local spin density functional calculations to understand the pressure effect on the Yb valence and compressibility are in good agreement with the experimental results.

  9. Angle-resolved environmental X-ray photoelectron spectroscopy: A new laboratory setup for photoemission studies at pressures up to 0.4 Torr

    SciTech Connect (OSTI)

    Mangolini, F.; Wabiszewski, G. E.; Egberts, P.; Ahlund, J.; Backlund, K.; Karlsson, P. G.; Adiga, V. P.; Streller, F.; Wannberg, B.; Carpick, R. W.

    2012-09-15

    The paper presents the development and demonstrates the capabilities of a new laboratory-based environmental X-ray photoelectron spectroscopy system incorporating an electrostatic lens and able to acquire spectra up to 0.4 Torr. The incorporation of a two-dimensional detector provides imaging capabilities and allows the acquisition of angle-resolved data in parallel mode over an angular range of 14 Degree-Sign without tilting the sample. The sensitivity and energy resolution of the spectrometer have been investigated by analyzing a standard Ag foil both under high vacuum (10{sup -8} Torr) conditions and at elevated pressures of N{sub 2} (0.4 Torr). The possibility of acquiring angle-resolved data at different pressures has been demonstrated by analyzing a silicon/silicon dioxide (Si/SiO{sub 2}) sample. The collected angle-resolved spectra could be effectively used for the determination of the thickness of the native silicon oxide layer.

  10. Small-angle X-ray Scattering from Magnetic Clusters and Structural...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    grain size is reduced. References: T. Wang, V. Mehta, Y. Ikeda, H. Do, K. Takano, S. Florez, B. D. Terris, B. Wu, C. Graves, M. Shu, R. Rick, A. Scherz, J. Sthr and O. Hellwig,...

  11. Time-Resolved Small-Angle X-ray Scattering Studies Revealed Three...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Stages of a T4 Virus Maturation Most eukaryotic viruses, including HIV, influenza and herpes viruses, undergo maturation when transitioning from the noninfectious provirion to the...

  12. Measurement of Carbon Condensation Using Small-angle X-ray Scattering...

    Office of Scientific and Technical Information (OSTI)

    Laboratory (LLNL), Livermore, CA Sponsoring Org: USDOE Country of Publication: United States Language: English Subject: 37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY...

  13. A short note on physical properties to irradiated nuclear fuel by means of X-ray diffraction and neutron scattering techniques

    SciTech Connect (OSTI)

    Abdullah, Yusof Husain, Hishamuddin; Hak, Cik Rohaida Che; Alias, Nor Hayati; Yusof, Mohd Reusmaazran; Kasim, Norasiah Ab; Zali, Nurazila Mat; Mohamed, Abdul Aziz

    2015-04-29

    For nuclear reactor applications, understanding the evolution of the fuel materials microstructure during irradiation are of great importance. This paper reviews the physical properties of irradiated nuclear fuel analysis which are considered to be of most importance in determining the performance behavior of fuel. X-rays diffraction was recognize as important tool to investigate the phase identification while neutron scattering analyses the interaction between uranium and other materials and also investigation of the defect structure.

  14. X-ray diffraction study of the structure of detonation nanodiamonds

    SciTech Connect (OSTI)

    Ozerin, A. N. Kurkin, T. S.; Ozerina, L. A.; Dolmatov, V. Yu.

    2008-01-15

    The spatial structure of aggregates formed by detonation nanodiamonds is investigated using the wide-angle and small-angle X-ray scattering techniques. The effective sizes of crystallites and the crystallite size distribution function are determined. The shape of scattering aggregates is restored from the small-angle X-ray scattering data. An analysis of the results obtained allowed the conclusion that the nanodiamond aggregates have an extended spatial structure composed of nine to ten clusters, each involving four to five crystallites with a crystal lattice of the diamond type.

  15. Combining THz laser excitation with resonant soft X-ray scattering at the Linac Coherent Light Source

    SciTech Connect (OSTI)

    Turner, Joshua J.; Dakovski, Georgi L.; Hoffmann, Matthias C.; Hwang, Harold Y.; Zarem, Alex; Schlotter, William F.; Moeller, Stefan; Minitti, Michael P.; Staub, Urs; Johnson, Steven; Mitra, Ankush; Swiggers, Michele; Noonan, Peter; Curiel, G. Ivan; Holmes, Michael

    2015-04-11

    This paper describes the development of new instrumentation at the Linac Coherent Light Source for conducting THz excitation experiments in an ultra high vacuum environment probed by soft X-ray diffraction. This consists of a cantilevered, fully motorized mirror system which can provide 600 kV cm⁻¹ electric field strengths across the sample and an X-ray detector that can span the full Ewald sphere with in-vacuum motion. The scientific applications motivated by this development, the details of the instrument, and spectra demonstrating the field strengths achieved using this newly developed system are discussed.

  16. Combining THz laser excitation with resonant soft X-ray scattering at the Linac Coherent Light Source

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Turner, Joshua J.; Dakovski, Georgi L.; Hoffmann, Matthias C.; Hwang, Harold Y.; Zarem, Alex; Schlotter, William F.; Moeller, Stefan; Minitti, Michael P.; Staub, Urs; Johnson, Steven; et al

    2015-04-11

    This paper describes the development of new instrumentation at the Linac Coherent Light Source for conducting THz excitation experiments in an ultra high vacuum environment probed by soft X-ray diffraction. This consists of a cantilevered, fully motorized mirror system which can provide 600 kV cm? electric field strengths across the sample and an X-ray detector that can span the full Ewald sphere with in-vacuum motion. The scientific applications motivated by this development, the details of the instrument, and spectra demonstrating the field strengths achieved using this newly developed system are discussed.

  17. Structural and magnetic properties of transition metal substituted BaFe{sub 2}As{sub 2} compounds studied by x-ray and neutron scattering

    SciTech Connect (OSTI)

    Kim, Min Gyu

    2012-08-28

    The purpose of my dissertation is to understand the structural and magnetic properties of the newly discovered FeAs-based superconductors and the interconnection between superconductivity, antiferromagnetism, and structure. X-ray and neutron scattering techniques are powerful tools to directly observe the structure and magnetism in this system. I used both xray and neutron scattering techniques on di#11;erent transition substituted BaFe2As2 compounds in order to investigate the substitution dependence of structural and magnetic transitions and try to understand the connections between them.

  18. A Survey of Students from the National School on Neutron and X-ray Scattering: Communication Habits and Preferences

    SciTech Connect (OSTI)

    Bryant, Rebecca

    2010-12-01

    Oak Ridge National Laboratory (ORNL) offers the scientific community unique access to two types of world-class neutron sources at a single site - the Spallation Neutron Source (SNS) and the High Flux Isotope Reactor (HFIR). The 85-MW HFIR provides one of the highest steady-state neutron fluxes of any research reactor in the world. And the SNS is one of the world's most intense pulse neutron beams. Management of these resources is the responsibility of the Neutron Sciences Directorate (NScD). NScD started conducting the National School on Neutron and X-ray Scattering (NXS) in conjunction with the Advanced Photon Source (APS) at Argonne National Laboratory in 2007. This survey was conducted to determine the most effective ways to reach students with information about what SNS and HFIR offer the scientific community, including content and communication vehicles. The emphasis is on gaining insights into compelling messages and the most effective channels, e.g., Web sites and social media, for communicating with students about neutron science The survey was conducted in two phases using a classic qualitative investigation to confirm language and content followed by a survey designed to quantify issues, assumptions, and working hypotheses. Phase I consisted of a focus group in late June 2010 with students attending NXS. The primary intent of the group was to inform development of an online survey. Phase two consisted of an online survey that was developed and pre-tested in July 2010 and launched on August 9, 2010 and remained in the field until September 9, 2010. The survey achieved an overall response rate of 48% for a total of 157 completions. The objective of this study is to determine the most effective ways to reach students with information about what SNS and HFIR offer the scientific community, including content and communication vehicles. The emphasis is on gaining insights into compelling messages and the most effective channels, e.g., Web sites, social media

  19. Structural phase transition of ternary dielectric SmGdO{sub 3}: Evidence from angle dispersive x-ray diffraction and Raman spectroscopic studies

    SciTech Connect (OSTI)

    Sharma, Yogesh E-mail: satya504@gmail.com Sahoo, Satyaprakash E-mail: satya504@gmail.com Misra, Pankaj; Pavunny, Shojan P.; Katiyar, Ram S. E-mail: satya504@gmail.com; Mishra, A. K.; Dwivedi, Abhilash; Sharma, S. M.

    2015-03-07

    High-pressure synchrotron based angle dispersive x-ray diffraction (ADXRD) studies were carried out on SmGdO{sub 3} (SGO) up to 25.7 GPa at room temperature. ADXRD results indicated a reversible pressure-induced phase transition from ambient monoclinic to hexagonal phase at ∼8.9 GPa. The observed pressure-volume data were fitted with the third order Birch-Murnaghan equation of state yielding zero pressure bulk modulus B{sub 0} = 132(22) and 177(9) GPa for monoclinic (B-type) and hexagonal (A-type) phases, respectively. Pressure dependent micro-Raman spectroscopy further confirmed the monoclinic to hexagonal phase transition at about 5.24 GPa. The mode Grüneisen parameters and pressure coefficients for different Raman modes corresponding to each individual phases of SGO were calculated using pressure dependent Raman mode analysis.

  20. SU-C-18C-02: Specifcation of X-Ray Projection Angles Which Are Aligned with the Aortic Valve Plane From a Planar Image of a Valvuloplasty Balloon Inflated Across the Aortic Valve

    SciTech Connect (OSTI)

    Fetterly, K; Mathew, V

    2014-06-01

    Purpose: Transcatheter aortic valve replacement (TAVR) procedures provide a method to implant a prosthetic aortic valve via a minimallyinvasive, catheter-based procedure. TAVR procedures require use of interventional fluoroscopy c-arm projection angles which are aligned with the aortic valve plane to minimize prosthetic valve positioning error due to x-ray imaging parallax. The purpose of this work is to calculate the continuous range of interventional fluoroscopy c-arm projection angles which are aligned with the aortic valve plane from a single planar image of a valvuloplasty balloon inflated across the aortic valve. Methods: Computational methods to measure the 3D angular orientation of the aortic valve were developed. Required inputs include a planar x-ray image of a known valvuloplasty balloon inflated across the aortic valve and specifications of x-ray imaging geometry from the DICOM header of the image. A-priori knowledge of the species-specific typical range of aortic orientation is required to specify the sign of the angle of the long axis of the balloon with respect to the x-ray beam. The methods were validated ex-vivo and in a live pig. Results: Ex-vivo experiments demonstrated that the angular orientation of a stationary inflated valvuloplasty balloon can be measured with precision less than 1 degree. In-vivo pig experiments demonstrated that cardiac motion contributed to measurement variability, with precision less than 3 degrees. Error in specification of x-ray geometry directly influences measurement accuracy. Conclusion: This work demonstrates that the 3D angular orientation of the aortic valve can be calculated precisely from a planar image of a valvuloplasty balloon inflated across the aortic valve and known x-ray geometry. This method could be used to determine appropriate c-arm angular projections during TAVR procedures to minimize x-ray imaging parallax and thereby minimize prosthetic valve positioning errors.

  1. Influence of static Jahn-Teller distortion on the magnetic excitation spectrum of PrO{sub 2}: A synchrotron x-ray and neutron inelastic scattering study

    SciTech Connect (OSTI)

    Webster, C. H.; Helme, L. M.; Boothroyd, A. T.; McMorrow, D. F.; Wilkins, S. B.; Detlefs, C.; Detlefs, B.; Bewley, R. I.; McKelvy, M. J.

    2007-10-01

    A synchrotron x-ray diffraction study of the crystallographic structure of PrO{sub 2} in the Jahn-Teller distorted phase is reported. The distortion of the oxygen sublattice, which was previously ambiguous, is shown to be a chiral structure in which neighboring oxygen chains have opposite chiralities. A temperature dependent study of the magnetic excitation spectrum, probed by neutron inelastic scattering, is also reported. Changes in the energies and relative intensities of the crystal field transitions provide an insight into the interplay between the static and dynamic Jahn-Teller effects.

  2. Scattering

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Scattering Print When a crystalline sample is illuminated with x-rays, the x-rays are scattered (diffracted) into very specific directions with various intensities. Detectors are used to measure this "diffraction pattern," which is then processed by computers to deduce the arrangement of atoms within the crystal. Hard x-rays have wavelengths comparable to the distance between atoms. Essentially everything we know about the atomic structure of materials is based on results from x-ray

  3. Scattering

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Scattering Print When a crystalline sample is illuminated with x-rays, the x-rays are scattered (diffracted) into very specific directions with various intensities. Detectors are used to measure this "diffraction pattern," which is then processed by computers to deduce the arrangement of atoms within the crystal. Hard x-rays have wavelengths comparable to the distance between atoms. Essentially everything we know about the atomic structure of materials is based on results from x-ray

  4. Serial femtosecond X-ray diffraction of enveloped virus microcrystals

    SciTech Connect (OSTI)

    Lawrence, Robert M.; Conrad, Chelsie E.; Zatsepin, Nadia A.; Grant, Thomas D.; Liu, Haiguang; James, Daniel; Nelson, Garrett; Subramanian, Ganesh; Aquila, Andrew; Hunter, Mark S.; Liang, Mengning; Boutet, Sbastien; Coe, Jesse; Spence, John C. H.; Weierstall, Uwe; Liu, Wei; Fromme, Petra; Cherezov, Vadim; Hogue, Brenda G.

    2015-08-20

    Serial femtosecond crystallography (SFX) using X-ray free-electron lasers has produced high-resolution, room temperature, time-resolved protein structures. We report preliminary SFX of Sindbis virus, an enveloped icosahedral RNA virus with ~700 diameter. Microcrystals delivered in viscous agarose medium diffracted to ~40 resolution. Small-angle diffuse X-ray scattering overlaid Bragg peaks and analysis suggests this results from molecular transforms of individual particles. Viral proteins undergo structural changes during entry and infection, which could, in principle, be studied with SFX. This is a pertinent step toward determining room temperature structures from virus microcrystals that may enable time-resolved studies of enveloped viruses.

  5. Serial femtosecond X-ray diffraction of enveloped virus microcrystals

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Lawrence, Robert M.; Conrad, Chelsie E.; Zatsepin, Nadia A.; Grant, Thomas D.; Liu, Haiguang; James, Daniel; Nelson, Garrett; Subramanian, Ganesh; Aquila, Andrew; Hunter, Mark S.; et al

    2015-08-20

    Serial femtosecond crystallography (SFX) using X-ray free-electron lasers has produced high-resolution, room temperature, time-resolved protein structures. We report preliminary SFX of Sindbis virus, an enveloped icosahedral RNA virus with ~700 Å diameter. Microcrystals delivered in viscous agarose medium diffracted to ~40 Å resolution. Small-angle diffuse X-ray scattering overlaid Bragg peaks and analysis suggests this results from molecular transforms of individual particles. Viral proteins undergo structural changes during entry and infection, which could, in principle, be studied with SFX. This is a pertinent step toward determining room temperature structures from virus microcrystals that may enable time-resolved studies of enveloped viruses.

  6. Glassy carbon as an absolute intensity calibration standard for small-angle scattering.

    SciTech Connect (OSTI)

    Zhang, F.; Ilavsky, J.; Long, G.; Allen, A.; Quintana, J.; Jemian, P.; NIST

    2010-05-01

    Absolute calibration of small-angle scattering (SAS) intensity data (measured in terms of the differential scattering cross section per unit sample volume per unit solid angle) is essential for many important aspects of quantitative SAS analysis, such as obtaining the number density, volume fraction, and specific surface area of the scatterers. It also enables scattering data from different instruments (light, X-ray, or neutron scattering) to be combined, and it can even be useful to detect the existence of artifacts in the experimental data. Different primary or secondary calibration methods are available. In the latter case, absolute intensity calibration requires a stable artifact with the necessary scattering profile. Glassy carbon has sometimes been selected as this intensity calibration standard. Here we review the spatial homogeneity and temporal stability of one type of commercially available glassy carbon that is being used as an intensity calibration standard at a number of SAS facilities. We demonstrate that glassy carbon is sufficiently homogeneous and stable during routine use to be relied upon as a suitable standard for absolute intensity calibration of SAS data.

  7. High-energy magnetic excitations in overdoped La 2 - x Sr x CuO 4 studied by neutron and resonant inelastic x-ray scattering

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Wakimoto, S.; Ishii, K.; Kimura, H.; Fujita, M.; Dellea, G.; Kummer, K.; Braicovich, L.; Ghiringhelli, G.; Debeer-Schmitt, L. M.; Granroth, G. E.

    2015-05-21

    We have performed neutron inelastic scattering and resonant inelastic x-ray scattering (RIXS) at the Cu-L₃ edge to study high-energy magnetic excitations at energy transfers of more than 100 meV for overdoped La2-xSrxCuO₄ with x=0.25 (Tc=15 K) and x=0.30 (nonsuperconducting) using identical single-crystal samples for the two techniques. From constant-energy slices of neutron-scattering cross sections, we have identified magnetic excitations up to ~250 meV for x=0.25. Although the width in the momentum direction is large, the peak positions along the (π,π) direction agree with the dispersion relation of the spin wave in the nondoped La₂CuO₄ (LCO), which is consistent with themore » previous RIXS results of cuprate superconductors. Using RIXS at the Cu-L₃ edge, we have measured the dispersion relations of the so-called paramagnon mode along both (π,π) and (π,0) directions. Although in both directions the neutron and RIXS data connect with each other and the paramagnon along (π,0) agrees well with the LCO spin-wave dispersion, the paramagnon in the (π,π) direction probed by RIXS appears to be less dispersive and the excitation energy is lower than the spin wave of LCO near (π/2,π/2). Thus, our results indicate consistency between neutron inelastic scattering and RIXS, and elucidate the entire magnetic excitation in the (π,π) direction by the complementary use of two probes. The polarization dependence of the RIXS profiles indicates that appreciable charge excitations exist in the same energy range of magnetic excitations, reflecting the itinerant character of the overdoped sample. A possible anisotropy in the charge excitation intensity might explain the apparent differences in the paramagnon dispersion in the (π,π) direction as detected by the x-ray scattering.« less

  8. Reflection soft X-ray microscope and method

    DOE Patents [OSTI]

    Suckewer, S.; Skinner, C.H.; Rosser, R.

    1993-01-05

    A reflection soft X-ray microscope is provided by generating soft X-ray beams, condensing the X-ray beams to strike a surface of an object at a predetermined angle, and focusing the X-ray beams reflected from the surface onto a detector, for recording an image of the surface or near surface features of the object under observation.

  9. Reflection soft X-ray microscope and method

    DOE Patents [OSTI]

    Suckewer, Szymon; Skinner, Charles H.; Rosser, Roy

    1993-01-01

    A reflection soft X-ray microscope is provided by generating soft X-ray beams, condensing the X-ray beams to strike a surface of an object at a predetermined angle, and focusing the X-ray beams reflected from the surface onto a detector, for recording an image of the surface or near surface features of the object under observation.

  10. Investigation of defect clusters in ion-irradiated Ni and NiCo using diffuse X-ray scattering and electron microscopy

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Olsen, Raina J.; Jin, Ke; Lu, Chenyang; Beland, Laurent K.; Wang, Lumin M.; Bei, Hongbin; Specht, Eliot D.; Larson, Bennett C.

    2016-01-01

    The nature of defect clusters in Ni and Nimore » $$_{50}$$Co$$_{50}$$ (NiCo) irradiated at room temperature with 2–16 MeV Ni ions is studied using asymptotic diffuse X-ray scattering and transmission electron microscopy (TEM). Analysis of the scattering data provides separate size distributions for vacancy and interstitial type defect clusters, showing that both types of defect clusters have a smaller size and higher density in NiCo than in Ni. Diffuse scattering results show good quantitative agreement with TEM results for cluster sizes greater than 4 nm diameter, but find that the majority of vacancy clusters are under 2 nm in NiCo, which, if not detected, would lead to the conclusion that defect density was actually lower in the alloy. Interstitial dislocation loops and stacking fault tetrahedra are identified by TEM. Lastly comparison of diffuse scattering lineshapes to those calculated for dislocation loops and SFTs indicates that most of the vacancy clusters are SFTs.« less

  11. Investigation of defect clusters in ion-irradiated Ni and NiCo using diffuse X-ray scattering and electron microscopy

    SciTech Connect (OSTI)

    Olsen, Raina J.; Jin, Ke; Lu, Chenyang; Beland, Laurent K.; Wang, Lumin M.; Bei, Hongbin; Specht, Eliot D.; Larson, Bennett C.

    2016-01-01

    The nature of defect clusters in Ni and Ni$_{50}$Co$_{50}$ (NiCo) irradiated at room temperature with 2–16 MeV Ni ions is studied using asymptotic diffuse X-ray scattering and transmission electron microscopy (TEM). Analysis of the scattering data provides separate size distributions for vacancy and interstitial type defect clusters, showing that both types of defect clusters have a smaller size and higher density in NiCo than in Ni. Diffuse scattering results show good quantitative agreement with TEM results for cluster sizes greater than 4 nm diameter, but find that the majority of vacancy clusters are under 2 nm in NiCo, which, if not detected, would lead to the conclusion that defect density was actually lower in the alloy. Interstitial dislocation loops and stacking fault tetrahedra are identified by TEM. Lastly comparison of diffuse scattering lineshapes to those calculated for dislocation loops and SFTs indicates that most of the vacancy clusters are SFTs.

  12. Vacancy-induced nanoscale phase separation in KxFe2–ySe₂ single crystals evidenced by Raman scattering and powder x-ray diffraction

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Lazarević, N.; Abeykoon, M.; Stephens, P. W.; Lei, Hechang; Bozin, E. S.; Petrovic, C.; Popović, Z. V.

    2012-08-06

    Polarized Raman scattering spectra of KxFe2–ySe₂ were analyzed in terms of peculiarities of both I4/m and I4/mmm space group symmetries. The presence of the Raman active modes from both space group symmetries (16 Raman-active modes of the I4/m phase and two Raman-active modes of the I4/mmm phase) confirmed the existence of two crystallographic domains with different space group symmetry in a KxFe2–ySe₂ sample. High-resolution synchrotron powder x-ray diffraction structural refinement of the same sample confirmed the two-phase description, and determined the atomic positions and occupancies for both domains.

  13. Resonant inelastic x-ray scattering study of charge excitations in superconducting and nonsuperconducting PrFeAsO₁₋y

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Jarrige, I.; Nomura, T.; Ishii, K.; Gretarsson, H.; Kim, Y.-J.; Kim, J.; Upton, M.; Casa, D.; Gog, T.; Ishikado, M.; et al

    2012-09-05

    We report the first observation by momentum-resolved resonant inelastic x-ray scattering of charge excitations in an iron-based superconductor and its parent compound, PrFeAsO₀.₇ and PrFeAsO, respectively, with two main results. First, using calculations based on a 16-band dp model, we show that the energy of the lowest-lying excitations, identified as dd interband transitions of dominant xz,yz orbital character, exhibits a dramatic dependence on electron correlation. This enables us to estimate the Coulomb repulsion U and Hund's coupling J, and to highlight the role played by J in these peculiar orbital-dependent electron correlation effects. Second, we show that short-range antiferromagnetic correlations,more » which are a prerequisite to the occurrence of these excitations at the Γ point, are still present in the superconducting state.« less

  14. Combined x-ray scattering, radiography, and velocity interferometry/streaked optical pyrometry measurements of warm dense carbon using a novel technique of shock-and-release

    SciTech Connect (OSTI)

    Falk, K.; Collins, L. A.; Kagan, G.; Kress, J. D.; Montgomery, D. S.; Srinivasan, B.; Gamboa, E. J.; Tzeferacos, P.; Benage, J. F.

    2014-05-15

    This work focused on a new application of the shock-and-release technique for equation of state (EOS) measurements. Warm dense matter states at near normal solid density and at temperatures close to 10 eV in diamond and graphite samples were created using a deep release from a laser-driven shock at the OMEGA laser facility. Independent temperature, density, and pressure measurements that do not depend on any theoretical models or simulations were obtained using imaging x-ray Thomson scattering, radiography, velocity interferometry, and streaked optical pyrometry. The experimental results were reproduced by the 2-D FLASH radiation hydrodynamics simulations finding a good agreement. The final EOS measurement was then compared with widely used SESAME EOS models as well as quantum molecular dynamics simulation results for carbon, which were very consistent with the experimental data.

  15. On the absence of a positive sound dispersion in the THz dynamics of glycerol: an inelastic x-ray scattering study

    SciTech Connect (OSTI)

    Cunsolo, Alessandro

    2012-10-23

    The high frequency transport properties of glycerol are derived from inelastic x-ray scattering spectra measured at different pressures and compared with ultrasound absorption data. As a result, the presence of two distinct relaxation processes is inferred: a slow one, occurring in the GHz window and having an essentially structural character, and a fast one, related instead to microscopic degrees of freedom. While the former originates a neat increase of the apparent, i.e. frequency-dependent, sound velocity, the latter induces no visible dispersive effects on the acoustic propagation. The observed behavior is likely paradigmatic of all glass formers near or below the melting and it is here discussed and explained in some detail.

  16. X-Ray Diagnostics

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    including film developing and scanning, and image plate scanning. Related images X-ray framing camera being loaded into the TIM in the Trident North Target Area. X-ray framing...

  17. Synthesis of 1 nm Pd Nanoparticles in a Microfluidic Reactor: Insights from in Situ X ray Absorption Fine Structure Spectroscopy and Small-Angle X ray Scattering

    SciTech Connect (OSTI)

    Karim, Ayman M.; Al Hasan, Naila M.; Ivanov, Sergei A.; Siefert, Soenke; Kelly, Ryan T.; Hallfors, Nicholas G.; Benavidez, Angelica D.; Kovarik, Libor; Jenkins, Aaron; Winans, R. E.; Datye, Abhaya K.

    2015-06-11

    In this paper we show that the temporal separation of nucleation and growth is not a necessary condition for the colloidal synthesis of monodisperse nanoparticles. The synthesis mechanism of Pd nanoparticles was determined by in situ XAFS and SAXS in a microfluidic reactor capable of millisecond up to an hour time resolution. The SAXS results showed two autocatalytic growth phases, a fast growth phase followed by a very slow growth phase. The steady increase in the number of particles throughout the two growth phases indicates the synthesis is limited by slow continuous nucleation. The transition from fast to slow growth was caused by rapid increase in bonding with the capping agent as shown by XAFS. Based on this fundamental understanding of the synthesis mechanism, we show that 1 nm monodisperse Pd nanoparticles can be synthesized at low temperature using a strong binding capping agent such as trioctylphosphine (TOP).

  18. High-energy magnetic excitations in overdoped La2-xSrxCuO4 studied by neutron and resonant inelastic X-ray scattering

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Wakimoto, S.; Ishii, K.; Kimura, H.; Fujita, M.; Dellea, G.; Kummer, K.; Braicovich, L.; Ghiringhelli, G.; Debeer-Schmitt, Lisa M.; Granroth, Garrett E.

    2015-05-21

    We have performed neutron inelastic scattering and resonant inelastic x-ray scattering (RIXS) at the Cu-L3 edge to study high-energy magnetic excitations at energy transfers of more than 100 meV for overdoped La2₋xSrxCuO4 with x=0.25 (Tc=15 K) and x=0.30 (nonsuperconducting) using identical single-crystal samples for the two techniques. From constant-energy slices of neutron-scattering cross sections, we have identified magnetic excitations up to ~250 meV for x=0.25. Although the width in the momentum direction is large, the peak positions along the (π,π) direction agree with the dispersion relation of the spin wave in the nondoped La2CuO4 (LCO), which is consistent with themore » previous RIXS results of cuprate superconductors. Using RIXS at the Cu-L3 edge, we have measured the dispersion relations of the so-called paramagnon mode along both (π,π) and (π,0) directions. Although in both directions the neutron and RIXS data connect with each other and the paramagnon along (π,0) agrees well with the LCO spin-wave dispersion, the paramagnon in the (π,π) direction probed by RIXS appears to be less dispersive and the excitation energy is lower than the spin wave of LCO near (π/2,π/2). Thus, our results indicate consistency between neutron inelastic scattering and RIXS, and elucidate the entire magnetic excitation in the (π,π) direction by the complementary use of two probes. The polarization dependence of the RIXS profiles indicates that appreciable charge excitations exist in the same energy range of magnetic excitations, reflecting the itinerant character of the overdoped sample. Lastly, we find a possible anisotropy in the charge excitation intensity might explain the apparent differences in the paramagnon dispersion in the (π,π) direction as detected by the x-ray scattering.« less

  19. Toward a Taxonomy of the Denatured State: Small Angle Scattering Studies of Unfolded Proteins

    SciTech Connect (OSTI)

    Millett, I.S.; Doniach, S.; Plaxco, K.W. (Stanford); (UCSB)

    2005-02-15

    Despite the critical role the unfolded state plays in defining protein folding kinetics and thermodynamics (Berg et al., 2002; Dunker, 2002; Shortle, 2002; Wright and Dyson, 2002), our understanding of its detailed structure remains rather rudimentary; the heterogeneity of the unfolded ensemble renders difficult or impossible its study by traditional, atomic-level structural methods. Consequently, recent years have seen a significant expansion of small-angle X-ray and neutron scattering (SAXS and SANS, respectively) techniques that provide direct, albeit rotationally and time-averaged, measures of the geometric properties of the unfolded ensemble. These studies have reached a critical mass, allowing us for the first time to define general observations regarding the nature of the geometry - and possibly the chemistry and physics - of unfolded proteins.

  20. Combined Use of Residual Dipolar Couplings and Solution X-ray Scattering To Rapidly Probe Rigid-Body Conformational Transitions in a Non-phosphorylatable Active-Site Mutant of the 128 kDa Enzyme I Dimer

    SciTech Connect (OSTI)

    Takayama, Yuki; Schwieters, Charles D.; Grishaev, Alexander; Ghirlando, Rodolfo; Clore, G. Marius (NIH)

    2012-10-23

    The first component of the bacterial phosphotransferase system, enzyme I (EI), is a multidomain 128 kDa dimer that undergoes large rigid-body conformational transitions during the course of its catalytic cycle. Here we investigate the solution structure of a non-phosphorylatable active-site mutant in which the active-site histidine is substituted by glutamine. We show that perturbations in the relative orientations and positions of the domains and subdomains can be rapidly and reliably determined by conjoined rigid-body/torsion angle/Cartesian simulated annealing calculations driven by orientational restraints from residual dipolar couplings and shape and translation information afforded by small- and wide-angle X-ray scattering. Although histidine and glutamine are isosteric, the conformational space available to a Gln side chain is larger than that for the imidazole ring of His. An additional hydrogen bond between the side chain of Gln189 located on the EIN{sup {alpha}/{beta}} subdomain and an aspartate (Asp129) on the EIN{sup {alpha}} subdomain results in a small ({approx}9{sup o}) reorientation of the EIN{sup {alpha}} and EIN{sup {alpha}/{beta}} subdomains that is in turn propagated to a larger reorientation ({approx}26{sup o}) of the EIN domain relative to the EIC dimerization domain, illustrating the positional sensitivity of the EIN domain and its constituent subdomains to small structural perturbations.

  1. X-Ray Diagnostics

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    X-Ray Diagnostics X-Ray Diagnostics Maintenance of existing devices and development of advanced concepts Contact John Oertel (505) 665-3246 Email Hot, dense matter produced by intense laser interaction with a solid target often produces x-rays with energies from 100 eV to those exceeding 100 keV. A suite of diagnostics and methods have been deployed at Trident to diagnose the x-ray emission from laser-matter interaction experiments, or to use the x-rays as a probe of dense matter. These

  2. Spherical grating based x-ray Talbot interferometry

    SciTech Connect (OSTI)

    Cong, Wenxiang E-mail: xiy2@rpi.edu Xi, Yan E-mail: xiy2@rpi.edu Wang, Ge E-mail: xiy2@rpi.edu

    2015-11-15

    Purpose: Grating interferometry is a state-of-the-art x-ray imaging approach, which can acquire information on x-ray attenuation, phase shift, and small-angle scattering simultaneously. Phase-contrast imaging and dark-field imaging are very sensitive to microstructural variation and offers superior contrast resolution for biological soft tissues. However, a common x-ray tube is a point-like source. As a result, the popular planar grating imaging configuration seriously restricts the flux of photons and decreases the visibility of signals, yielding a limited field of view. The purpose of this study is to extend the planar x-ray grating imaging theory and methods to a spherical grating scheme for a wider range of preclinical and clinical applications. Methods: A spherical grating matches the wave front of a point x-ray source very well, allowing the perpendicular incidence of x-rays on the grating to achieve a higher visibility over a larger field of view than the planer grating counterpart. A theoretical analysis of the Talbot effect for spherical grating imaging is proposed to establish a basic foundation for x-ray spherical gratings interferometry. An efficient method of spherical grating imaging is also presented to extract attenuation, differential phase, and dark-field images in the x-ray spherical grating interferometer. Results: Talbot self-imaging with spherical gratings is analyzed based on the Rayleigh–Sommerfeld diffraction formula, featuring a periodic angular distribution in a polar coordinate system. The Talbot distance is derived to reveal the Talbot self-imaging pattern. Numerical simulation results show the self-imaging phenomenon of a spherical grating interferometer, which is in agreement with the theoretical prediction. Conclusions: X-ray Talbot interferometry with spherical gratings has a significant practical promise. Relative to planar grating imaging, spherical grating based x-ray Talbot interferometry has a larger field of view and

  3. X-ray diffraction and Raman scattering study of Cr-doped ZnFe{sub 2}O{sub 4} spinel ferrites

    SciTech Connect (OSTI)

    Kumar, Ashwini; Sharma, Poorva; Varshney, Dinesh

    2015-06-24

    XRD and Raman scattering measurements were made on polycrystalline ZnFe{sub 2-x}Cr{sub x}O{sub 4} (x=0.0, 0.1, 0.2) spinel ferrites as prepared by solid-state reaction route. Rietveld refined X-ray diffraction pattern confirmed the formation of single-phase and are indexed in cubic structure with Fd3m space group. Slight reduction in the lattice parameter from 8.435 to 8.410 Ǻ, with Cr{sup 3+} ion substitution has been observed. From Raman scattering spectra, the modes of ZnFe{sub 1.9}Cr{sub 0.1}O{sub 4} and ZnFe{sub 1.8}Cr{sub 0.2}O{sub 4} are shifted towards the lower frequency side as compared to ZnFe{sub 2}O{sub 4}, this red shift is attributed to higher atomic mass of Zn (65.39 amu) as compared to Fe (55.84 amu)

  4. Total reflection inelastic x-ray scattering from a 10 nm thick La{sub 0.6}Sr{sub 0.2}CoO{sub 3} thin film.

    SciTech Connect (OSTI)

    Fister, T. T.; Fong, D. D.; Eastman, J. A.; Iddir, H.; Zapol, P.; Fuoss, P. H.; Balasubramanian, M.; Gordon, R. A.; Balasubramaniam, K. R.; Salvador, P. A.; Simon Fraser Univ.; Carnegie Mellon Univ.

    2011-01-18

    To study equilibrium changes in composition, valence, and electronic structure near the surface and into the bulk, we demonstrate the use of a new approach, total-reflection inelastic x-ray scattering, as a sub-keV spectroscopy capable of depth profiling chemical changes in thin films with nanometer resolution. By comparing data acquired under total x-ray reflection and penetrating conditions, we are able to separate the O K-edge spectra from a 10 nm La{sub 0.6}Sr{sub 0.4}CoO{sub 3} thin film from that of the underlying SrTiO{sub 3} substrate. With a smaller wavelength probe than comparable soft x-ray absorption measurements, we also describe the ability to easily access dipole-forbidden final states, using the dramatic evolution of the La N{sub 4,5} edge with momentum transfer as an example.

  5. High-resolution ab initio three-dimensional x-ray diffraction microscopy

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Chapman, Henry N.; Barty, Anton; Marchesini, Stefano; Noy, Aleksandr; Hau-Riege, Stefan P.; Cui, Congwu; Howells, Malcolm R.; Rosen, Rachel; He, Haifeng; Spence, John C. H.; et al

    2006-01-01

    Coherent x-ray diffraction microscopy is a method of imaging nonperiodic isolated objects at resolutions limited, in principle, by only the wavelength and largest scattering angles recorded. We demonstrate x-ray diffraction imaging with high resolution in all three dimensions, as determined by a quantitative analysis of the reconstructed volume images. These images are retrieved from the three-dimensional diffraction data using no a priori knowledge about the shape or composition of the object, which has never before been demonstrated on a nonperiodic object. We also construct two-dimensional images of thick objects with greatly increased depth of focus (without loss of transverse spatialmore » resolution). These methods can be used to image biological and materials science samples at high resolution with x-ray undulator radiation and establishes the techniques to be used in atomic-resolution ultrafast imaging at x-ray free-electron laser sources.« less

  6. X-ray beamsplitter

    DOE Patents [OSTI]

    Ceglio, Natale M.; Stearns, Daniel S.; Hawryluk, Andrew M.; Barbee, Jr., Troy W.

    1989-01-01

    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.

  7. X-ray beamsplitter

    DOE Patents [OSTI]

    Ceglio, N.M.; Stearns, D.G.; Hawryluk, A.M.; Barbee, T.W. Jr.

    1987-08-07

    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. 6 figs.

  8. Chest x-Rays

    Broader source: Energy.gov [DOE]

    The B-reading is a special reading of a standard chest x-ray film performed by a physician certified by the National Institute for Occupational Safety and Health (NIOSH). The reading looks for changes on the chest x-ray that may indicate exposure and disease caused by agents such as asbestos or silica.

  9. X-Ray Data from the X-Ray Data Booklet Online

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Thompson, Albert C.; Attwood, David T.; Gullikson, Eric M.; Howells, Malcolm R.; Kortright, Jeffrey B.; Robinson, Arthur L.; Underwood, James H.; Kim, Kwang-Je; Kirz, Janos; Lindau, Ingolf; Pianetta, Piero; Winick, Herman; Williams, Gwyn P.; Scofield, James H.

    The original X-Ray Data Booklet, published in 1985, became a classic reference source. The online version has been significantly revised and updated to reflect today's science. Hundreds of pages of authoritative data provide the x-ray properties of elements, information on synchrotron radiation, scattering processes, optics and detectors, and other related calculations, formulas, and data tables.

  10. X-ray generator

    DOE Patents [OSTI]

    Dawson, John M.

    1976-01-01

    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.