Depth distribution of multiple order X-ray scatter

International Nuclear Information System (INIS)

Yao Weiguang; Leszczynski, Konrad

2008-01-01

Scatter can significantly affect quality of projectional X-ray radiographs and tomographic reconstructions. With this in mind, we examined some of the physical properties of multiple orders of scatter of X-ray photons traversing through a layer of scattering media such as water. Using Monte Carlo techniques, we investigated depth distributions of interactions between incident X-ray photons and water before the resulting scattered photons reach the detector plane. Effects of factors such as radiation field size, air gap, thickness of the layer of scattering medium and X-ray energy, on the scatter were included in the scope of this study. The following scatter characteristics were observed: (1) for a layer of scattering material corresponding to the typical subject thickness in medical imaging, frequency distribution of locations of the last scattering interaction increases approximately exponentially with depth, and the higher the order of scatter or the energy of the incident photon, the narrower is the distribution; (2) for the second order scatter, the distribution of locations of the first interaction is more uniform than that of the last interaction and is dependent on the energy of the primary photons. Theoretical proofs for some of these properties are given. These properties are important to better understanding of effects of scatter on the radiographic and tomographic imaging process and to developing effective methods for scatter correction

Basic X-ray scattering for soft matter

CERN Document Server

De Jeu, Wim H

2016-01-01

X-ray scattering is a well-established technique in materials science. Several excellent textbooks exist in the field, typically written by physicists who use mathematics to make things clear. Often these books do not reach students and scientists in the field of soft matter (polymers, liquid crystals, colloids, and self-assembled organic systems), who usually have a chemical-oriented background with limited mathematics. Moreover, often these people like to know more about x-ray scattering as a technique to be used, but do not necessarily intend to become an expert. This volume is unique in trying to accommodate both points. The aim of the book is to explain basic principles and applications of x-ray scattering in a simple way. The intention is a paperback of limited size that people will like to have on hand rather than on a shelf. Second, it includes a large variety of examples of x-ray scattering of soft matter with, at the end of each chapter, a more elaborate case study. Third, the book contains a separa...

Healing X-ray scattering images

Directory of Open Access Journals (Sweden)

Jiliang Liu

2017-07-01

Full Text Available X-ray scattering images contain numerous gaps and defects arising from detector limitations and experimental configuration. We present a method to heal X-ray scattering images, filling gaps in the data and removing defects in a physically meaningful manner. Unlike generic inpainting methods, this method is closely tuned to the expected structure of reciprocal-space data. In particular, we exploit statistical tests and symmetry analysis to identify the structure of an image; we then copy, average and interpolate measured data into gaps in a way that respects the identified structure and symmetry. Importantly, the underlying analysis methods provide useful characterization of structures present in the image, including the identification of diffuse versus sharp features, anisotropy and symmetry. The presented method leverages known characteristics of reciprocal space, enabling physically reasonable reconstruction even with large image gaps. The method will correspondingly fail for images that violate these underlying assumptions. The method assumes point symmetry and is thus applicable to small-angle X-ray scattering (SAXS data, but only to a subset of wide-angle data. Our method succeeds in filling gaps and healing defects in experimental images, including extending data beyond the original detector borders.

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

Science.gov (United States)

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

2015-01-01

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.

Workshop report on new directions in x-ray scattering

International Nuclear Information System (INIS)

Brown, G.; Del Grande, N.K.; Fuoss, P.; Mallett, J.H.; Pratt, R.; Templeton, D.

1987-01-01

This report is a summary of the Workshop on New Directions in X-Ray Scattering held at the Asilomar Conference Center, Pacific Grove, California, April 2-5, 1985. The report primarily consists of the edited transcript of the final review session of the workshop, in which members of a panel summarized the proceedings. It is clear that we are close to achieving an accurate theory of scattering in independent particle approximation, but for edge regions, there is need to go beyond this approach. Much of what is experimentally interesting in scattering is occurring between the photoabsorption edge and the photoelectric threshold. Applications in condensed matter and biological and chemical material studies are expanding, exploiting higher intensity sources and faster time resolution as in magnetic scattering and surface studies. Storage rings are now conventional sources, and new high-intensity beam lines are under development; the free electron laser is one of the more speculative sources. Recent work in x-ray scattering has led to advances in x-ray optics, and conversely, advances in x-ray optics have benefitted our understanding of x-ray scattering

Investigations of time resolved x-ray wide-angle scattering and x-ray small-angle scattering at DESY

International Nuclear Information System (INIS)

Zachmann, H.G.; Gehrke, R.; Prieske, W.; Riekel, C.

1985-01-01

Instrumentation is described for the simultaneous wide-angle and small-angle x-ray scattering. The method was applied to the study of the isothermal crystallization of polyethylene terephthalates. In agreement with the classical theories of crystallization, the data showed that the density difference between the crystals and the non-crystalline regions does not change with time. The mechanisms of melting, recrystallization, and crystal thickening were investigated by small-angle x-ray scattering with stepwise changes and continuous changes of temperature using polyethylene terephthalate

X-Ray-Scattering Measurements Of Strain In PEEK

Science.gov (United States)

Cebe, Peggy; Lowry, Lynn E.; Chung, Shirley Y.; Yavrouian, Andre H.; Gupta, Amitava

1988-01-01

Internal stress relieved by heating above glass-transition temperature. Report describes wide-angle x-ray scattering and differential scanning calorimetry of specimens of poly(etheretherketone) having undergone various thermal treatments. Wide-angle x-ray scattering particularly useful in determining distances between atoms, crystallinity, and related microstructurally generated phenomena, as thermal expansion and strain. Calorimetric measurements aid interpretation of scattering measurements by enabling correlation with thermal effects.

Resonant X-ray scattering in correlated systems

Energy Technology Data Exchange (ETDEWEB)

Murakami, Youichi [High Energy Accelerator Research Organization, Tsukuba, Ibaraki (Japan). Inst. of Materials Structure Science; Ishihara, Sumio (ed.) [Tohoku Univ., Sendai, Miyagi (Japan). Dept. of Physics

2017-03-01

The research and its outcomes presented here is devoted to the use of X-ray scattering to study correlated electron systems and magnetism. Different X-ray based methods are provided to analyze three dimensional electron systems and the structure of transition-metal oxides. Finally the observation of multipole orderings with X-ray diffraction is shown.

Resonant x-ray scattering in correlated systems

CERN Document Server

Ishihara, Sumio

2017-01-01

The research and its outcomes presented here is devoted to the use of x-ray scattering to study correlated electron systems and magnetism. Different x-ray based methods are provided to analyze three dimensional electron systems and the structure of transition-metal oxides. Finally the observation of multipole orderings with x-ray diffraction is shown.

Anisotropy enhanced X-ray scattering from solvated transition metal complexes

DEFF Research Database (Denmark)

Biasin, Elisa; van Driel, Tim B.; Levi, Gianluca

2018-01-01

Time-resolved X-ray scattering patterns from photoexcited molecules in solution are in many cases anisotropic at the ultrafast time scales accessible at X-ray free-electron lasers (XFELs). This anisotropy arises from the interaction of a linearly polarized UV-Vis pump laser pulse with the sample......, which induces anisotropic structural changes that can be captured by femtosecond X-ray pulses. In this work, a method for quantitative analysis of the anisotropic scattering signal arising from an ensemble of molecules is described, and it is demonstrated how its use can enhance the structural...... sensitivity of the time-resolved X-ray scattering experiment. This method is applied on time-resolved X-ray scattering patterns measured upon photoexcitation of a solvated di-platinum complex at an XFEL, and the key parameters involved are explored. It is shown that a combined analysis of the anisotropic...

A study on the measurement of effective energy of scattering X-rays

International Nuclear Information System (INIS)

Oogama, Noboru; Fujimoto, Nobuhisa; Nishitani, Motohiro; Yamada, Katsuhiko

1995-01-01

Only a few studies have been reported on the measurement and evaluation of the effective energy of scattering X-rays using an ionization chamber. The reason for this is due to the difficulty in accurately measuring attenuation curve in scattering X-rays lacking any directional properties. We could come up with a new method for calculating the effective energy of scattering X-rays by utilizing their spectra data. First, for analysing the accuracy of our calculation method with using primary X-rays, a comparison was made of calculated values of the effective energy obtained by our calculation method with the measurement values obtained using an ionization chamber. The results gave the calculated values agreeing with the measurement values within a maximum error of 2%, and this method was very helpful in measuring the effective energy of the scattering X-rays. Consequently, this method was capable of measuring the effective energy of scattering X-rays in the following parameters: X-ray tube voltage, scattering angle and size of scatterer. In conclusion, it is considered that our method could solve the present difficulty regarding the measurement of effective energy of the scattering X-rays, and provided a useful procedure concerning the study of radiation protection. (author)

Defect properties from X-ray scattering experiments

International Nuclear Information System (INIS)

Peisl, H.

1976-01-01

Lattice distortions due to defects in crystals can be studied most directly by elastic X-ray or neutron scattering experiments. The 'size' of the defects can be determined from the shift of the Bragg reflections. Defect induced diffuse scattering intensity close to and between Bragg reflections gives information on the strength and symmetry of the distortion fields and yields the atomic structure of point defects (interstitials, vacancies, small aggregates). Diffuse scattering is a very sensitive method to decide whether defects are present as isolated point defects or have formed aggregates. X-ray scattering has been used to study defects produced in various ionic crystals by γ- and neutron irradiation. After an introduction to the principles of the method the experimental results will be reviewed and discussed in some detail. (orig.) [de

A sample cell to study hydrate formation with x-ray scattering

International Nuclear Information System (INIS)

Conrad, Heiko; Lehmkuehler, Felix; Sternemann, Christian; Feroughi, Omid; Tolan, Metin; Simonelli, Laura; Huotari, Simo

2009-01-01

We present a new sample cell for measuring nonresonant inelastic x-ray scattering spectra of a tetrahydrofuran (THF)-water liquid mixture and THF hydrate. The hydrate is formed inside the cell after nucleation seeds have been offered by a special magnetic stirring mechanism. Hydrate formation was verified by wide angle x-ray scattering and nonresonant x-ray Raman scattering spectra at the oxygen K-edge. A broad range of scattering angles can be studied with this cell which is necessary for momentum transfer dependent inelastic x-ray scattering. This cell is ideal to examine other liquid hydrate formers or other liquid samples, which have to be mixed in situ during the measurements.

Diffuse scattering of neutrons and X-rays

International Nuclear Information System (INIS)

Novion, C.H. de

1978-01-01

Diffuse scattering is used to study defect concentrations of about 10 -4 in the case of X-rays and 10 -3 in the case of neutrons. The foundations of diffuse scattering formalism are given, some experimental devices described and a few applications discussed: study by diffraction on powders of defects in CeOsub(2-x); short-range order study by X-rays on Cusub(0.75) Ausub(0.25); short-range order study by neutrons on Cusub(0.435)Nisub(0.565); short-range order study by electrons TiOx; study of irradiation-induced self-interstitials in Al; study of holes created by neutrons in Al [fr

Combining NMR and small angle X-ray and neutron scattering in the structural analysis of a ternary protein-RNA complex

International Nuclear Information System (INIS)

Hennig, Janosch; Wang, Iren; Sonntag, Miriam; Gabel, Frank; Sattler, Michael

2013-01-01

Many processes in the regulation of gene expression and signaling involve the formation of protein complexes involving multi-domain proteins. Individual domains that mediate protein-protein and protein-nucleic acid interactions are typically connected by flexible linkers, which contribute to conformational dynamics and enable the formation of complexes with distinct binding partners. Solution techniques are therefore required for structural analysis and to characterize potential conformational dynamics. Nuclear magnetic resonance spectroscopy (NMR) provides such information but often only sparse data are obtained with increasing molecular weight of the complexes. It is therefore beneficial to combine NMR data with additional structural restraints from complementary solution techniques. Small angle X-ray/neutron scattering (SAXS/SANS) data can be efficiently combined with NMR-derived information, either for validation or by providing additional restraints for structural analysis. Here, we show that the combination of SAXS and SANS data can help to refine structural models obtained from data-driven docking using HADDOCK based on sparse NMR data. The approach is demonstrated with the ternary protein-protein-RNA complex involving two RNA recognition motif (RRM) domains of Sex-lethal, the N-terminal cold shock domain of Upstream-to-N-Ras, and msl-2 mRNA. Based on chemical shift perturbations we have mapped protein-protein and protein-RNA interfaces and complemented this NMR-derived information with SAXS data, as well as SANS measurements on subunit-selectively deuterated samples of the ternary complex. Our results show that, while the use of SAXS data is beneficial, the additional combination with contrast variation in SANS data resolves remaining ambiguities and improves the docking based on chemical shift perturbations of the ternary protein-RNA complex.

Combining NMR and small angle X-ray and neutron scattering in the structural analysis of a ternary protein-RNA complex

Energy Technology Data Exchange (ETDEWEB)

Hennig, Janosch; Wang, Iren; Sonntag, Miriam [Institute of Structural Biology, Helmholtz Zentrum Muenchen (Germany); Gabel, Frank [Extremophiles and Large Molecular Assemblies Group (ELMA), Institut de Biologie Structurale (IBS) CEA-CNRS-UJF (France); Sattler, Michael, E-mail: sattler@helmholtz-muenchen.de [Institute of Structural Biology, Helmholtz Zentrum Muenchen (Germany)

2013-05-15

Many processes in the regulation of gene expression and signaling involve the formation of protein complexes involving multi-domain proteins. Individual domains that mediate protein-protein and protein-nucleic acid interactions are typically connected by flexible linkers, which contribute to conformational dynamics and enable the formation of complexes with distinct binding partners. Solution techniques are therefore required for structural analysis and to characterize potential conformational dynamics. Nuclear magnetic resonance spectroscopy (NMR) provides such information but often only sparse data are obtained with increasing molecular weight of the complexes. It is therefore beneficial to combine NMR data with additional structural restraints from complementary solution techniques. Small angle X-ray/neutron scattering (SAXS/SANS) data can be efficiently combined with NMR-derived information, either for validation or by providing additional restraints for structural analysis. Here, we show that the combination of SAXS and SANS data can help to refine structural models obtained from data-driven docking using HADDOCK based on sparse NMR data. The approach is demonstrated with the ternary protein-protein-RNA complex involving two RNA recognition motif (RRM) domains of Sex-lethal, the N-terminal cold shock domain of Upstream-to-N-Ras, and msl-2 mRNA. Based on chemical shift perturbations we have mapped protein-protein and protein-RNA interfaces and complemented this NMR-derived information with SAXS data, as well as SANS measurements on subunit-selectively deuterated samples of the ternary complex. Our results show that, while the use of SAXS data is beneficial, the additional combination with contrast variation in SANS data resolves remaining ambiguities and improves the docking based on chemical shift perturbations of the ternary protein-RNA complex.

X-ray holography with an atomic scatterer

Energy Technology Data Exchange (ETDEWEB)

Mityureva, A.A.; Smirnov, V.V., E-mail: valery_smirnov@mail.ru

2016-08-15

X-ray holography scheme with reference scatterer consisting of heavy atom as reference center and its link to an object consisting of several light atoms and using controlled variation of the alignment is represented. The scheme can reproduce an object in three dimensions with atomic resolution. The distorting factors of reconstruction are considered. - Highlights: • X-ray holography scheme with a reference wave formed by atomic scatterer. • 3D object reconstruction with atomic resolution from the set of holograms. • Simple formula for the distorting factor in reconstruction.

X-ray generator based on Compton scattering

NARCIS (Netherlands)

Androsov, V.P.; Agafonov, A.V.; Botman, J.I.M.; Bulyak, E.V.; Drebot, I.; Gladkikh, P.I.; Grevtsev, V.; Ivashchenko, V.; Karnaukhov, I.M.; Lapshin, V.I.

2005-01-01

Nowadays, the sources of the X-rays based on a storage ring with low beam energy and Compton scattering of intense laser beam are under development in several laboratories. In the paper the state-of-art in development and construction of cooperative project of a Kharkov advanced X-ray source NESTOR

Multiple scattering approach to X-ray absorption spectroscopy

International Nuclear Information System (INIS)

Benfatto, M.; Wu Ziyu

2003-01-01

In this paper authors present the state of the art of the theoretical background needed for analyzing X-ray absorption spectra in the whole energy range. The multiple-scattering (MS) theory is presented in detail with some applications on real systems. Authors also describe recent progress in performing geometrical fitting of the XANES (X-ray absorption near-edge structure) energy region and beyond using a full multiple-scattering approach

Development of general X-ray scattering model

International Nuclear Information System (INIS)

Gray, Joe; Wendt, Scott

2015-01-01

X-ray scattering is a complex process made difficult to describe due to the effects of a complex energy spectrum interacting with a wide range of material types in complex geometry. The scattering is further complicated by the volume of material illuminated and the experimental configuration of the data acquisition. The importance of accounting for the key physics in scattering modeling is critical to the viability of the model. For example, scattering in the detector and the speed of the detector, as measured by the absorbed dose needed to produce a signal, are important in capturing undercut effects. Another example is the noise properties of the detectors are dependent on photon energy. We report on a semi-empirical treatment of x-ray scattering that includes a full energy treatment for a wide range of material types. We also include complex geometry effects that the part shape introduces. The treatment is based on experimental measurements using an energy dispersive germanium detector over energies from treatment is showing good results with experimental measurements of the scattering component agreeing with the model results to the 10% level over the range of x-ray energies and materials typical in industrial applications. Computation times for this model are in the 20 keV to 320 keV. Detector stripping routines for detector artifacts were developed. The computation time is in the range of a few minutes on a typical PC

Resonant inelastic x-ray scattering studies of elementary excitations

NARCIS (Netherlands)

Ament, Lucas Johannes Peter (Luuk)

2010-01-01

Resonant Inelastic X-ray Scattering (RIXS) is an X-ray in, X-ray out technique that enables one to study the dispersion of excitations in solids. In this thesis, we investigated how various elementary excitations of transition metal oxides show up in RIXS spectra.

Resonance magnetic x-ray scattering study of erbium

DEFF Research Database (Denmark)

Sanyal, M.K.; Gibbs, D.; Bohr, J.

1994-01-01

The magnetic phases of erbium have been studied by resonance x-ray-scattering techniques. When the incident x-ray energy is tuned near the L(III) absorption edge, large resonant enhancements of the magnetic scattering are observed above 18 K. We have measured the energy and polarization dependence...... of this magnetic scattering and analyzed it using a simple model based on electric dipole and quadrupole transitions among atomic orbitals. The line shapes can be fitted to a magnetic structure combining both c-axis-modulated and basal-plane components. Below 18 K, we have observed unusual behavior of the magnetic...

X-ray scattering studies of surfaces and interfaces

International Nuclear Information System (INIS)

Sanyal, M.K.

1998-01-01

Here we shall briefly review the basics and some applications of x-ray specular reflectivity and diffuse scattering techniques. These x-ray scattering techniques are uniquely suited to study of the structure of surfaces and interfaces at atomic resolutions as they are nondestructive and can probe even interfaces which are buried. The study of structure of surfaces and interfaces is not only required in understanding physics in reduced dimensions but is also essential in developing technologically important materials

X-ray coherent scattering tomography of textured material (Conference Presentation)

Science.gov (United States)

Zhu, Zheyuan; Pang, Shuo

2017-05-01

Small-angle X-ray scattering (SAXS) measures the signature of angular-dependent coherently scattered X-rays, which contains richer information in material composition and structure compared to conventional absorption-based computed tomography. SAXS image reconstruction method of a 2 or 3 dimensional object based on computed tomography, termed as coherent scattering computed tomography (CSCT), enables the detection of spatially-resolved, material-specific isotropic scattering signature inside an extended object, and provides improved contrast for medical diagnosis, security screening, and material characterization applications. However, traditional CSCT methods assumes materials are fine powders or amorphous, and possess isotropic scattering profiles, which is not generally true for all materials. Anisotropic scatters cannot be captured using conventional CSCT method and result in reconstruction errors. To obtain correct information from the sample, we designed new imaging strategy which incorporates extra degree of detector motion into X-ray scattering tomography for the detection of anisotropic scattered photons from a series of two-dimensional intensity measurements. Using a table-top, narrow-band X-ray source and a panel detector, we demonstrate the anisotropic scattering profile captured from an extended object and the reconstruction of a three-dimensional object. For materials possessing a well-organized crystalline structure with certain symmetry, the scatter texture is more predictable. We will also discuss the compressive schemes and implementation of data acquisition to improve the collection efficiency and accelerate the imaging process.

Small angle neutron scattering and small angle X-ray scattering ...

Indian Academy of Sciences (India)

Abstract. The morphology of carbon nanofoam samples comprising platinum nanopar- ticles dispersed in the matrix was characterized by small angle neutron scattering (SANS) and small angle X-ray scattering (SAXS) techniques. Results show that the structure of pores of carbon matrix exhibits a mass (pore) fractal nature ...

Low-angle X-ray scattering from spices

International Nuclear Information System (INIS)

Desouky, O.S.; Ashour, Ahmed H.; Abdullah, Mohamed I.; Elshemey, Wael M.

2002-01-01

Low-angle scattering of X-rays is characterized by the presence of one or more peaks in the forward direction of scattering. These peaks are due to the interference of photons coherently scattered from the molecules of the medium. Thus these patterns are closely linked to the molecular structure of the investigated medium. In this work, low-angle X-ray scattering (LAXS) profiles of five spices; pimpinella anisum (anise), coriandrum sativum (coriander), cuminum cyminum (cumin), foenculum vulgare (fennel) and nigella sativa (nigella or black cumin) are presented after extensive measurements. It is found that all spices exhibit one characteristic peak at a scattering angle around 10 deg. This is equivalent to a value x=0.0565 A -1 , where x=sin(θ/2)/λ. The full width at half maximum (FWHM) of this peak is found to be characteristic for each type of the investigated spices. The possibility to detect the irradiation of these spices from their LAXS profiles is also examined after 10, 20, 30 and 40 kGy doses of gamma radiation. Except for anise, coriander and cumin at 40 kGy, there are no detectable deviations from the control samples in the scattering profiles of irradiated samples. These results comply with the recommendations of the FDA (US Food and Drug Administration) which defines 30 kGy as the maximum dose for irradiation of spices. The present technique could be used to detect over-irradiation, which causes damage to the molecular structure of some spices

Resonant magnetic scattering of polarized soft x rays

Energy Technology Data Exchange (ETDEWEB)

Sacchi, M. [Centre Universitaire Paris-Sud, Orsay (France); Hague, C.F. [Universite Pierre et Marie Curie, Paris (France); Gullikson, E.M.; Underwood, J. [Ernest Orlando Lawrence Berkeley National Lab., CA (United States)

1997-04-01

Magnetic effects on X-ray scattering (Bragg diffraction, specular reflectivity or diffuse scattering) are a well known phenomenon, and they also represent a powerful tool for investigating magnetic materials since it was shown that they are strongly enhanced when the photon energy is tuned across an absorption edge (resonant process). The resonant enhancement of the magnetic scattering has mainly been investigated at high photon energies, in order to match the Bragg law for the typical lattice spacings of crystals. In the soft X-ray range, even larger effects are expected, working for instance at the 2p edges of transition metals of the first row or at the 3d edges of rare earths (300-1500 eV), but the corresponding long wavelengths prevent the use of single crystals. Two approaches have been recently adopted in this energy range: (i) the study of the Bragg diffraction from artificial structures of appropriate 2d spacing; (ii) the analysis of the specular reflectivity, which contains analogous information but has no constraints related to the lattice spacing. Both approaches have their own specific advantages: for instance, working under Bragg conditions provides information about the (magnetic) periodicity in ordered structures, while resonant reflectivity can easily be related to electronic properties and absorption spectra. An important aspect common to all the resonant X-ray scattering techniques is the element selectivity inherent to the fact of working at a specific absorption edge: under these conditions, X-ray scattering becomes in fact a spectroscopy. Results are presented for films of iron and cobalt.

Kharkov X-ray Generator Based On Compton Scattering

International Nuclear Information System (INIS)

Shcherbakov, A.; Zelinsky, A.; Mytsykov, A.; Gladkikh, P.; Karnaukhov, I.; Lapshin, V.; Telegin, Y.; Androsov, V.; Bulyak, E.; Botman, J.I.M.; Tatchyn, R.; Lebedev, A.

2004-01-01

Nowadays X-ray sources based on storage rings with low beam energy and Compton scattering of intense laser beams are under development in several laboratories. An international cooperative project of an advanced X-ray source of this type at the Kharkov Institute of Physics and Technology (KIPT) is described. The status of the project is reviewed. The design lattice of the storage ring and calculated X-ray beam parameters are presented. The results of numerical simulation carried out for proposed facility show a peak spectral X-ray intensity of about 1014 can be produced

Mechanism of adenylate kinase: Site-directed mutagenesis versus x-ray and NMR

International Nuclear Information System (INIS)

Tsai, Mingdaw; Yan, Honggao

1991-01-01

Controversy is an integral part of scientific research and is often a precursor to the truth. However, this lesson has been learned in a very hard way in the case of the structure-function relationship of adenylate kinase (AK), which catalyzes the interconversion between MgATP+AMP and MgADP+ADP. While this small kinase has been considered a model kinase and the enzyme-substrate interaction of AK was among the first investigated by X-ray crystallography and NMR the substrate binding sites deduced from the early studies by these two powerful techniques (termed the X-ray model and the NMR model, respectively) were dramatically different. Ironically, both models have had substantial impact on researchers in related fields. The problems have finally been dealt with since 1987 by the interplay between site-directed mutagenesis, X-ray, and NMR. The purpose of this review is not only to summarize the current knowledge in the structure-function relationship of adenylate kinase but also to accurately document and critically analyze historical developments in the hope that history will not be repeated

Anomalous scattering and isomorphous replacement in X-ray diffuse scattering holography

Czech Academy of Sciences Publication Activity Database

Kopecký, Miloš; Kub, Jiří; Busetto, E.; Lausi, A.; Fábry, Jan; Šourek, Zbyněk

2007-01-01

Roč. 204, č. 8 (2007), s. 2572-2577 ISSN 1862-6300 R&D Projects: GA AV ČR IAA100100529; GA MŠk LA 287 Institutional research plan: CEZ:AV0Z10100523; CEZ:AV0Z10100520 Keywords : x-ray difuse scattering * x-ray holography Subject RIV: BM - Solid Matter Physics ; Magnetism

Mapping of unfolding states of integral helical membrane proteins by GPS-NMR and scattering techniques

DEFF Research Database (Denmark)

Calcutta, Antonello; Jessen, Christian M; Behrens, Manja Annette

2012-01-01

induced by unfolding of an integral membrane protein, namely TFE-induced unfolding of KcsA solubilized by the n-dodecyl ß-d-maltoside (DDM) surfactant is investigated by the recently introduced GPS-NMR (Global Protein folding State mapping by multivariate NMR) (Malmendal et al., PlosONE 5, e10262 (2010......)) along with dynamic light scattering (DLS) and small-angle X-ray scattering (SAXS). GPS-NMR is used as a tool for fast analysis of the protein unfolding processes upon external perturbation, and DLS and SAXS are used for further structural characterization of the unfolding states. The combination allows...

Structural characterization of cellulosic materials using x-ray and neutron scattering

Energy Technology Data Exchange (ETDEWEB)

Penttila, P.

2013-11-01

Cellulosic biomass can be used as a feedstock for sustainable production of biofuels and various other products. A complete utilization of the raw material requires understanding on its structural aspects and their role in the various processes. In this thesis, x-ray and neutron scattering methods were applied to study the structure of various cellulosic materials and how they are affected in different processes. The obtained results were reviewed in the context of a model for the cellulose nanostructure. The dimensions of cellulose crystallites and the crystallinity were determined with wide-angle x-ray scattering (WAXS), whereas the nanoscale fibrillar structure of cellulose was characterized with small-angle x-ray and neutron scattering (SAXS and SANS). The properties determined with the small-angle scattering methods included specific surface areas and distances characteristic of the packing of cellulose microfibrils. Also other physical characterization methods, such as x-ray microtomography, infrared spectroscopy, and solid-state NMR were utilized in this work. In the analysis of the results, a comprehensive understanding of the structural changes throughout a range of length scales was aimed at. Pretreatment of birch sawdust by pressurized hot water extraction was observed to increase the crystal width of cellulose, as determined with WAXS, even though the cellulose crystallinity was slightly decreased. A denser packing of microfibrils caused by the removal of hemicelluloses and lignin in the extraction was evidenced by SAXS. This resulted in the opening of new pores between the microfibril bundles and an increase of the specific surface area. Enzymatic hydrolysis of microcrystalline cellulose (MCC) did not lead to differences in the average crystallinity or crystal size of the hydrolysis residues, which was explained to be caused by limitations due to the large size of the enzymes as compared to the pores inside the fibril aggregates. The SAXS intensities

Crystal defect studies using x-ray diffuse scattering

Energy Technology Data Exchange (ETDEWEB)

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.

Crystal defect studies using x-ray diffuse scattering

International Nuclear Information System (INIS)

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

Ultrafast x-ray scattering on nanoparticle dynamics

International Nuclear Information System (INIS)

Plech, A; Ibrahimkutty, S; Issenmann, D; Kotaidis, V; Siems, A

2013-01-01

Pulsed X-ray scattering is used for the determination of structural dynamics of laser-irradiated gold particles. By combining several scattering methods such as powder scattering, small angle scattering and diffuse wide angle scattering it is possible to reconstruct the kinetics of structure evolution on several lengths scales and derive complementary information on the particles and their local environment. A generic structural phase diagram for the reaction as function of delay time after laser excitation and laser fluence can be constructed.

X-ray scattering studies of non-equilibrium ordering processes

International Nuclear Information System (INIS)

Nagler, S.E.

1990-01-01

We report on the progress of our project entitled ''X-ray Scattering of Non-Equilibrium Ordering Processes.'' During the past year we have made the first synchrotron measurements of ordering in Cu 3 Au have revealed the presence of an intermediate, non-equilibrium ordered state. Preliminary work involving x-ray magnetic scattering has been carried out. Work is continuing in these areas as well as on related problems. 5 refs

Interference between magnetism and surface roughness in coherent soft X-ray scattering

International Nuclear Information System (INIS)

Rahmim, A.; Tixier, S.; Tiedje, T.; Eisebitt, S.; Lorgen, M.; Scherer, R.; Eberhardt, W.; Luning, J.; Scholl, A.

2002-01-01

In coherent soft x-ray scattering from magnetically ordered surfaces there are contributions to the scattering from the magnetic domains, from the surface roughness, and from the diffraction associated with the pinhole aperture used as a coherence filter. In the present work, we explore the interplay between these contributions by analyzing speckle patterns in diffusely scattered x rays from the surface of magnetic thin films. Magnetic contrast from the surface of anti ferro magnetically ordered LaFeO3 films is caused by magnetic linear dichroism in resonant x-ray scattering. The samples studied possess two types of domains with their magnetic orientations perpendicular to each other. By tuning the x-ray energy from one of the two Fe-L3 resonant absorption peaks to the other, the relative amplitudes of the x-ray scattering from the two domains is inverted which results in speckle pattern changes. A theoretical expression is derived for the intensity correlation between the speckle patterns with the magnetic contrast inverted and not inverted. The model is found to be in good agreement with the x-ray-scattering observations and independent measurements of the surface roughness. An analytical expression for the correlation function gives an explicit relation between the change in the speckle pattern and the roughness, and magnetic and aperture scattering. Changes in the speckle pattern are shown to arise from beating of magnetic scattering with the roughness scattering and diffraction from the aperture. The largest effect is found when the surface roughness scatter is comparable in intensity to the magnetic scatter

Preliminary Examination of X-ray Scattering from Human Tissues

International Nuclear Information System (INIS)

Desouky, O.S.; Wilkinson, S.; Hall, C.; Rogers, K.; Round, A.

2008-01-01

Small Angle x-ray scattering (SAXS) and wide angle x-ray scattering (WAXS) patterns have been recorded from different human soft tissues using x-ray synchrotron radiation.Pathological breast, normal kidney and lung tissues show SAXS peaks at q-values equal to 0.291 nm -1 and 0.481 nm -1 (d 21.6 nm and d =13. nm) which are the 3 r d and 5 t h order of the well known axial D-spacing of collagen fibrils. The diffraction is particularly intense in the meridional direction indicating some febrile alignment. In contrast, the normal tissue of brain, liver and heart shows diffuse scatter.The wide-angle coherent scattering from normal human tissues of brain, liver, heart, lung, and kidney is typical of that for amorphous materials. The scatter of the healthy adipose breast tissue shows a sharp peak at momentum transfer 1.24 nm -1 (d= 0.417 nm). The data of the other tissues appears to consist of a broad scattering peak. The two scattering regimes succeed in differentiating between the two major components of breast tissue, collagen and adipose tissue. The results of this study suggest that the soft tissues may have scattering patterns that are characteristics for the particular tissue types and tissue disease state. These results indicate that it may be possible use the coherent scattering as a diagnostic tool

Three-dimensional reciprocal space x-ray coherent scattering tomography of two-dimensional object.

Science.gov (United States)

Zhu, Zheyuan; Pang, Shuo

2018-04-01

X-ray coherent scattering tomography is a powerful tool in discriminating biological tissues and bio-compatible materials. Conventional x-ray scattering tomography framework can only resolve isotropic scattering profile under the assumption that the material is amorphous or in powder form, which is not true especially for biological samples with orientation-dependent structure. Previous tomography schemes based on x-ray coherent scattering failed to preserve the scattering pattern from samples with preferred orientations, or required elaborated data acquisition scheme, which could limit its application in practical settings. Here, we demonstrate a simple imaging modality to preserve the anisotropic scattering signal in three-dimensional reciprocal (momentum transfer) space of a two-dimensional sample layer. By incorporating detector movement along the direction of x-ray beam, combined with a tomographic data acquisition scheme, we match the five dimensions of the measurements with the five dimensions (three in momentum transfer domain, and two in spatial domain) of the object. We employed a collimated pencil beam of a table-top copper-anode x-ray tube, along with a panel detector to investigate the feasibility of our method. We have demonstrated x-ray coherent scattering tomographic imaging at a spatial resolution ~2 mm and momentum transfer resolution 0.01 Å -1 for the rotation-invariant scattering direction. For any arbitrary, non-rotation-invariant direction, the same spatial and momentum transfer resolution can be achieved based on the spatial information from the rotation-invariant direction. The reconstructed scattering profile of each pixel from the experiment is consistent with the x-ray diffraction profile of each material. The three-dimensional scattering pattern recovered from the measurement reveals the partially ordered molecular structure of Teflon wrap in our sample. We extend the applicability of conventional x-ray coherent scattering tomography to

Study on the influences of X Ray Scattering on radioscopic inspection

Energy Technology Data Exchange (ETDEWEB)

Wozniak, M.; Torrent, J.; Bancelin, A. [SNECMA NDE Dept. Laboratory, France, Evry Corbeil, 91 - Evry (France)

2007-07-01

This study issued from European project 'Verdict' (Virtual Evaluation and Robust Detection for engine Components non destructive Testing), aimed at developing and evaluating X Ray Non Destructive Method simulation. An qualitative appreciation and quantification for X Ray scattering for modelling (SINDBAD software) was identified. The effect of such radiation on radiogram results in a disturbing blur for interpretation of indications. The method and the results described are innovative in the analysis of X Ray scattering because for aeronautic field, the configurations used with this energy range are breakthrough. The approach followed consists in an experimental and practical method for evaluating scattered radiation on final image issued from the inspection. Experimental tests results confirmed that the influence of scattering radiation are linked to density variation, geometry of parts in the axis of direct radiation and spatial area. This study performed in industrial configurations contributed to improve X Ray scattering understanding. (authors)

Sources of the X-rays Based on Compton Scattering

International Nuclear Information System (INIS)

Androsov, V.; Bulyak, E.; Gladkikh, P.; Karnaukhov, I.; Mytsykov, A.; Telegin, Yu.; Shcherbakov, A.; Zelinsky, A.

2007-01-01

The principles of the intense X-rays generation by laser beam scattering on a relativistic electron beam are described and description of facilities assigned to produce the X-rays based on Compton scattering is presented. The possibilities of various types of such facilities are estimated and discussed. The source of the X-rays based on a storage ring with low beam energy is described in details and advantages of the sources of such type are discussed.The results of calculation and numerical simulation carried out for laser electron storage ring NESTOR that is under development in NSC KIPT show wide prospects of the accelerator facility of such type

Soft X-ray radiation damage in EM-CCDs used for Resonant Inelastic X-ray Scattering

Science.gov (United States)

Gopinath, D.; Soman, M.; Holland, A.; Keelan, J.; Hall, D.; Holland, K.; Colebrook, D.

2018-02-01

Advancement in synchrotron and free electron laser facilities means that X-ray beams with higher intensity than ever before are being created. The high brilliance of the X-ray beam, as well as the ability to use a range of X-ray energies, means that they can be used in a wide range of applications. One such application is Resonant Inelastic X-ray Scattering (RIXS). RIXS uses the intense and tuneable X-ray beams in order to investigate the electronic structure of materials. The photons are focused onto a sample material and the scattered X-ray beam is diffracted off a high resolution grating to disperse the X-ray energies onto a position sensitive detector. Whilst several factors affect the total system energy resolution, the performance of RIXS experiments can be limited by the spatial resolution of the detector used. Electron-Multiplying CCDs (EM-CCDs) at high gain in combination with centroiding of the photon charge cloud across several detector pixels can lead to sub-pixel spatial resolution of 2-3 μm. X-ray radiation can cause damage to CCDs through ionisation damage resulting in increases in dark current and/or a shift in flat band voltage. Understanding the effect of radiation damage on EM-CCDs is important in order to predict lifetime as well as the change in performance over time. Two CCD-97s were taken to PTB at BESSY II and irradiated with large doses of soft X-rays in order to probe the front and back surfaces of the device. The dark current was shown to decay over time with two different exponential components to it. This paper will discuss the use of EM-CCDs for readout of RIXS spectrometers, and limitations on spatial resolution, together with any limitations on instrument use which may arise from X-ray-induced radiation damage.

Oil classification using X-ray scattering and principal component analysis

Energy Technology Data Exchange (ETDEWEB)

Almeida, Danielle S.; Souza, Amanda S.; Lopes, Ricardo T., E-mail: dani.almeida84@gmail.com, E-mail: ricardo@lin.ufrj.br, E-mail: amandass@bioqmed.ufrj.br [Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ (Brazil); Oliveira, Davi F.; Anjos, Marcelino J., E-mail: davi.oliveira@uerj.br, E-mail: marcelin@uerj.br [Universidade do Estado do Rio de Janeiro (UERJ), Rio de Janeiro, RJ (Brazil). Inst. de Fisica Armando Dias Tavares

2015-07-01

X-ray scattering techniques have been considered promising for the classification and characterization of many types of samples. This study employed this technique combined with chemical analysis and multivariate analysis to characterize 54 vegetable oil samples (being 25 olive oils)with different properties obtained in commercial establishments in Rio de Janeiro city. The samples were chemically analyzed using the following indexes: iodine, acidity, saponification and peroxide. In order to obtain the X-ray scattering spectrum, an X-ray tube with a silver anode operating at 40kV and 50 μA was used. The results showed that oils cab ne divided in tow large groups: olive oils and non-olive oils. Additionally, in a multivariate analysis (Principal Component Analysis - PCA), two components were obtained and accounted for more than 80% of the variance. One component was associated with chemical parameters and the other with scattering profiles of each sample. Results showed that use of X-ray scattering spectra combined with chemical analysis and PCA can be a fast, cheap and efficient method for vegetable oil characterization. (author)

Oil classification using X-ray scattering and principal component analysis

International Nuclear Information System (INIS)

Almeida, Danielle S.; Souza, Amanda S.; Lopes, Ricardo T.; Oliveira, Davi F.; Anjos, Marcelino J.

2015-01-01

X-ray scattering techniques have been considered promising for the classification and characterization of many types of samples. This study employed this technique combined with chemical analysis and multivariate analysis to characterize 54 vegetable oil samples (being 25 olive oils)with different properties obtained in commercial establishments in Rio de Janeiro city. The samples were chemically analyzed using the following indexes: iodine, acidity, saponification and peroxide. In order to obtain the X-ray scattering spectrum, an X-ray tube with a silver anode operating at 40kV and 50 μA was used. The results showed that oils cab ne divided in tow large groups: olive oils and non-olive oils. Additionally, in a multivariate analysis (Principal Component Analysis - PCA), two components were obtained and accounted for more than 80% of the variance. One component was associated with chemical parameters and the other with scattering profiles of each sample. Results showed that use of X-ray scattering spectra combined with chemical analysis and PCA can be a fast, cheap and efficient method for vegetable oil characterization. (author)

Leakage and scattered radiation from hand-held dental x-ray unit

International Nuclear Information System (INIS)

Kim, Eun Kyung

2007-01-01

To compare the leakage and scattered radiation from hand-held dental X-ray unit with radiation from fixed dental X-ray unit. For evaluation we used one hand-held dental X-ray unit and Oramatic 558 (Trophy Radiologie, France), a fixed dental X-ray unit. Doses were measured with Unfors Multi-O-Meter 512L at the right and left hand levels of X-ray tube head part for the scattered and leakage radiation when human skull DXTTR ΙΙΙ was exposed to both dental X-ray units. And for the leakage radiation only, doses were measured at the immediately right, left, superior and posterior side of the tube head part when air was exposed. Exposure parameters of hand-held dental X-ray unit were 70 kVp, 3 mA , 0.1 second, and of fixed X-ray unit 70 kVp, 8 mA, 0.45 second. The mean dose at the hand level when human skull DXTTR ΙΙΙ was exposed with portable X-ray unit 6.39 μGy, and the mean dose with fixed X-ray unit 3.03 μGy (p<0.001). The mean dose at the immediate side of the tube head part when air was exposed with portable X-ray unit was 2.97 μGy and with fixed X-ray unit the mean dose was 0.68 μGy (p<0.01). The leakage and scattered radiation from hand-held dental radiography was greater than from fixed dental radiography

Leakage and scattered radiation from hand-held dental x-ray unit

Energy Technology Data Exchange (ETDEWEB)

Kim, Eun Kyung [Dankook Univ. School of Dentistry, Seoul (Korea, Republic of)

2007-06-15

To compare the leakage and scattered radiation from hand-held dental X-ray unit with radiation from fixed dental X-ray unit. For evaluation we used one hand-held dental X-ray unit and Oramatic 558 (Trophy Radiologie, France), a fixed dental X-ray unit. Doses were measured with Unfors Multi-O-Meter 512L at the right and left hand levels of X-ray tube head part for the scattered and leakage radiation when human skull DXTTR {iota}{iota}{iota} was exposed to both dental X-ray units. And for the leakage radiation only, doses were measured at the immediately right, left, superior and posterior side of the tube head part when air was exposed. Exposure parameters of hand-held dental X-ray unit were 70 kVp, 3 mA , 0.1 second, and of fixed X-ray unit 70 kVp, 8 mA, 0.45 second. The mean dose at the hand level when human skull DXTTR {iota}{iota}{iota} was exposed with portable X-ray unit 6.39 {mu}Gy, and the mean dose with fixed X-ray unit 3.03 {mu}Gy (p<0.001). The mean dose at the immediate side of the tube head part when air was exposed with portable X-ray unit was 2.97 {mu}Gy and with fixed X-ray unit the mean dose was 0.68 {mu}Gy (p<0.01). The leakage and scattered radiation from hand-held dental radiography was greater than from fixed dental radiography.

Anomalous x-ray scattering

International Nuclear Information System (INIS)

Wendin, G.

1979-01-01

The availability of tunable synchrotron radiation has made it possible systematically to perform x-ray diffraction studies in regions of anomalous scattering near absorption edges, e.g. in order to derive phase information for crystal structure determination. An overview is given of recent experimental and theoretical work and discuss the properties of the anomalous atomic scattering factor, with emphasis on threshold resonances and damping effects. The results are applied to a discussion of the very strong anomalous dispersion recently observed near the L 3 edge in a cesium complex. Also given is an overview of elements and levels where similar behavior can be expected. Finally, the influence of solid state and chemical effects on the absorption edge structure is discussed. 64 references

Search for photon–photon elastic scattering in the X-ray region

International Nuclear Information System (INIS)

Inada, T.; Yamaji, T.; Adachi, S.; Namba, T.; Asai, S.; Kobayashi, T.; Tamasaku, K.; Tanaka, Y.; Inubushi, Y.; Sawada, K.; Yabashi, M.; Ishikawa, T.

2014-01-01

We report the first results of a search for real photon–photon scattering using X rays. A novel system is developed to split and collide X-ray pulses by applying interferometric techniques. A total of 6.5×10 5 pulses (each containing about 10 11 photons) from an X-ray Free-Electron Laser are injected into the system. No scattered events are observed, and an upper limit of 1.7×10 −24  m 2 (95% C.L.) is obtained on the photon–photon elastic scattering cross section at 6.5 keV

Scattering of x-ray from crystal surfaces

International Nuclear Information System (INIS)

Andrews, S.R.; Cowley, R.A.

1985-01-01

X-ray measurements performed on a variety of materials demonstrate that it is possible to observe diffuse scattering that originates in the abrupt change of density at a crystal surface. Such a discontinuity gives rise, in general, to rods of scattering in reciprocal space which are most intense close to the Bragg peaks tau and are well defined for sufficiently smooth surfaces. For wave-vector transfer Q=tau+q the q-dependence of the intensity of scattering gives information on the topographic structure of the crystal surface. Experimental results on crystals of GaAs and KTaO 3 , with surfaces prepared in various ways, were obtained using conventional x-ray techniques with a rotating anode source and can be described by a continuum model of the surface. There are discrepancies between the predictions of the models and the experimental results and the suggest that further experiments are needed to achieve a more complete understanding. (author)

Identifying low and high density amorphous phases during zeolite amorphisation using small and wide angle X-ray scattering

International Nuclear Information System (INIS)

Meneau, F.; Greaves, G.N.

2005-01-01

In situ experiments following the thermal amorphisation of zeolites reveal massive increases in small angle X-ray scattering (SAXS), persisting well beyond the stage where wide angle X-ray scattering (WAXS) can detect that any crystalline phase is present. This heterogeneity in the amorphised phase is attributed to the transition from a low density amorphous phase (LDA) to a high density amorphous phase (HDA) at the glass transition. The fractions of zeolite, LDA and HDA phases obtained from SAXS analysis are discussed in the context of non-linear changes detected in 29 Si solid state NMR during zeolite amorphisation. Whilst the HDA phase is chemically disordered, the LDA phase exhibits much of the Al-Si ordering present in the starting zeolite. These findings are considered in the context of perfect glasses predicted to occur when super strong liquids are supercooled

Application of small-angle X-ray scattering for differentiation among breast tumors

International Nuclear Information System (INIS)

Changizi, V.; Kheradmand, A. Arab; Oghabian, M.A.

2008-01-01

Small-angle X-ray scattering (SAXS) is an X-ray diffraction-based technique where a narrow collimated beam of X-rays is focused onto a sample and the scattered X-rays recorded by a detector. The pattern of the scattered X-rays carries information on the molecular structure of the material. As breast cancer is the most widespread cancer in women and differentiation among its tumors is important, this project compared the results of coherent X-ray scattering measurements obtained from benign and malignant breast tissues. The energy-dispersive method with a setup including X-ray tube, primary collimator, sample holder, secondary collimator and high-purity germanium (HpGe) detector was used. One hundred thirty-one breast-tissue samples, including normal, fibrocystic changes and carcinoma, were studied at the 6 deg scattering angle. Diffraction profiles (corrected scattered intensity versus momentum transfer) of normal, fibrocystic changes and carcinoma were obtained. These profiles showed a few peak positions for adipose (1.15 ± 0.06 nm -1 ), mixed normal (1.15 ± 0.06 nm -1 and 1.4 ± 0.04 nm -1 ), fibrocystic changes (1.46 ± 0.05 nm -1 and 1.74 ± 0.04 nm -1 ) and carcinoma (1.55 ± 0.04 nm -1 , 1.73 ± 0.06 nm -1 , 1.85 ± 0.05 nm -1 ). We were able to differentiate between normal, fibrocystic changes (benign) and carcinoma (malignant) breast tissues by SAXS. However, we were unable to differentiate between different types of carcinoma. (author)

Application of small-angle X-ray scattering for differentiation among breast tumors

Directory of Open Access Journals (Sweden)

Changizi V

2008-01-01

Full Text Available Small-angle X-ray scattering (SAXS is an X-ray diffraction-based technique where a narrow collimated beam of X-rays is focused onto a sample and the scattered X-rays recorded by a detector. The pattern of the scattered X-rays carries information on the molecular structure of the material. As breast cancer is the most widespread cancer in women and differentiation among its tumors is important, this project compared the results of coherent X-ray scattering measurements obtained from benign and malignant breast tissues. The energy-dispersive method with a setup including X-ray tube, primary collimator, sample holder, secondary collimator and high-purity germanium (HpGe detector was used. One hundred thirty-one breast-tissue samples, including normal, fibrocystic changes and carcinoma, were studied at the 6° scattering angle. Diffraction profiles (corrected scattered intensity versus momentum transfer of normal, fibrocystic changes and carcinoma were obtained. These profiles showed a few peak positions for adipose (1.15 ± 0.06 nm -1 , mixed normal (1.15 ± 0.06 nm -1 and 1.4 ± 0.04 nm -1 , fibrocystic changes (1.46 ± 0.05 nm -1 and 1.74 ± 0.04 nm -1 and carcinoma (1.55 ± 0.04 nm -1 , 1.73 ± 0.06 nm -1 , 1.85 ± 0.05 nm -1 . We were able to differentiate between normal, fibrocystic changes (benign and carcinoma (malignant breast tissues by SAXS. However, we were unable to differentiate between different types of carcinoma.

Toroidal silicon polarization analyzer for resonant inelastic x-ray scattering

Energy Technology Data Exchange (ETDEWEB)

Gao, Xuan [Department of Physics, Western Michigan University, Kalamazoo, Michigan 49008-5252 (United States); Key Laboratory of Multi-scale Manufacturing Technology, Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing 400714 (China); Casa, Diego; Kim, Jungho; Gog, Thomas [Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Li, Chengyang [Department of Physics, Western Michigan University, Kalamazoo, Michigan 49008-5252 (United States); Department of Physics, South University of Science and Technology of China, Shenzhen 518055 (China); Burns, Clement [Department of Physics, Western Michigan University, Kalamazoo, Michigan 49008-5252 (United States)

2016-08-15

Resonant Inelastic X-ray Scattering (RIXS) is a powerful probe for studying electronic excitations in materials. Standard high energy RIXS measurements do not measure the polarization of the scattered x-rays, which is unfortunate since it carries information about the nature and symmetry of the excitations involved in the scattering process. Here we report the fabrication of thin Si-based polarization analyzers with a double-concave toroidal surface, useful for L-edge RIXS studies in heavier atoms such as the 5-d transition metals.

Measuring scatter radiation in diagnostic x rays for radiation protection purposes

International Nuclear Information System (INIS)

Panayiotakis, George; Vlachos, Ioannis; Delis, Harry; Tsantilas, Xenophon; Kalyvas, Nektarios; Kandarakis, Ioannis

2015-01-01

During the last decades, radiation protection and dosimetry in medical X-ray imaging practice has been extensively studied. The purpose of this study was to measure secondary radiation in a conventional radiographic room, in terms of ambient dose rate equivalent H*(10) and its dependence on the radiographic exposure parameters such as X-ray tube voltage, tube current and distance. With some exceptions, the results indicated that the scattered radiation was uniform in the space around the water cylindrical phantom. The results also showed that the tube voltage and filtration affect the dose rate due to the scatter radiation. Finally, the scattered X-ray energy distribution was experimentally calculated. (authors)

In situ microfluidic dialysis for biological small-angle X-ray scattering

DEFF Research Database (Denmark)

Skou, Magda; Skou, Soren; Jensen, Thomas Glasdam

2014-01-01

Owing to the demand for low sample consumption and automated sample changing capabilities at synchrotron small-angle X-ray (solution) scattering (SAXS) beamlines, X-ray microfluidics is receiving continuously increasing attention. Here, a remote-controlled microfluidic device is presented for sim...... in incidental sample purification. Hence, this versatile microfluidic device enables investigation of experimentally induced structural changes under dynamically controllable sample conditions. (C) 2014 International Union of Crystallography......Owing to the demand for low sample consumption and automated sample changing capabilities at synchrotron small-angle X-ray (solution) scattering (SAXS) beamlines, X-ray microfluidics is receiving continuously increasing attention. Here, a remote-controlled microfluidic device is presented...

X-ray, neutron, and electron scattering. Report of a materials sciences workshop

International Nuclear Information System (INIS)

1977-08-01

The ERDA Workshop on X-ray, Neutron, and Electron Scattering to assess needs and establish priorities for energy-related basic research on materials. The general goals of the Workshop were: (1) to review various energy technologies where x-ray, neutron, and electron scattering techniques might make significant contributions, (2) to identify present and future materials problems in the energy technologies and translate these problems into requirements for basic research by x-ray, neutron, and electron scattering techniques, (3) to recommend research areas utilizing these three scattering techniques that should be supported by the DPR Materials Sciences Program, and (4) to assign priorities to these research areas

X-ray scattering from periodic arrays of quantum dots

International Nuclear Information System (INIS)

Holy, V; Stangl, J; Lechner, R T; Springholz, G

2008-01-01

Three-dimensional periodic arrays of self-organized quantum dots in semiconductor multilayers are investigated by high-resolution x-ray scattering. We demonstrate that the statistical parameters of the dot array can be determined directly from the scattering data without performing a numerical simulation of the scattered intensity.

X-ray scattering at liquid surfaces and interfaces

International Nuclear Information System (INIS)

Daillant, Jean

2000-01-01

X-ray and neutron reflectivity techniques have become quite popular for the analysis of surfaces and interfaces over the last ten years. In this review, we discuss the specific aspects of both specular and diffuse x-ray reflectivity at liquid interfaces. We start from a model liquid surface for which the scattering cross-section can be calculated in terms of thermally excited capillary and acoustic waves, and we examine in detail the experimental consequences of the large bulk scattering and of the low q divergence of the surface scattering. Deviations from the simple calculated behaviour point to interesting phenomena which can be studied in detail, like the appearance of a bending stiffness. The method is illustrated through the discussion of representative studies of liquid surfaces, of surfactant monolayers, of liquid-liquid interfaces and of microemulsions. (author)

Protein NMR Structures Refined with Rosetta Have Higher Accuracy Relative to Corresponding X-ray Crystal Structures

Science.gov (United States)

2014-01-01

We have found that refinement of protein NMR structures using Rosetta with experimental NMR restraints yields more accurate protein NMR structures than those that have been deposited in the PDB using standard refinement protocols. Using 40 pairs of NMR and X-ray crystal structures determined by the Northeast Structural Genomics Consortium, for proteins ranging in size from 5–22 kDa, restrained Rosetta refined structures fit better to the raw experimental data, are in better agreement with their X-ray counterparts, and have better phasing power compared to conventionally determined NMR structures. For 37 proteins for which NMR ensembles were available and which had similar structures in solution and in the crystal, all of the restrained Rosetta refined NMR structures were sufficiently accurate to be used for solving the corresponding X-ray crystal structures by molecular replacement. The protocol for restrained refinement of protein NMR structures was also compared with restrained CS-Rosetta calculations. For proteins smaller than 10 kDa, restrained CS-Rosetta, starting from extended conformations, provides slightly more accurate structures, while for proteins in the size range of 10–25 kDa the less CPU intensive restrained Rosetta refinement protocols provided equally or more accurate structures. The restrained Rosetta protocols described here can improve the accuracy of protein NMR structures and should find broad and general for studies of protein structure and function. PMID:24392845

Resonant diffuse X-ray scattering from magnetic multilayers

International Nuclear Information System (INIS)

Spezzani, Carlo; Torelli, Piero; Delaunay, Renaud; Hague, C.F.; Petroff, Frederic; Scholl, Andreas; Gullikson, E.M.; Sacchi, Maurizio

2004-01-01

We have measured field-dependent resonant diffuse scattering from a magnetoresistive Co/Cu multilayer. We have observed that the magnetic domain size in zero field depends on the magnetic history of the sample. The results of the X-ray scattering analysis have been compared to PEEM images of the magnetic domains

Electron Dynamics by Inelastic X-Ray Scattering

CERN Document Server

Schülke, Winfried

2007-01-01

The book offers the first comprehensive review of experimental methods, theory, and successful applications of synchrotron radiation based inelastic X-ray scattering (IXS) spectroscopy, which enables the investigation of electron dynamics in condensed matter (correlated motion and excitation).

CHEMICAL APPLICATIONS OF INELASTIC X-RAY SCATTERING

Energy Technology Data Exchange (ETDEWEB)

HAYASHI,H.; UDAGAWA,Y.; GILLET,J.M.; CALIEBE,W.A.; KAO,C.C.

2001-08-01

Inelastic x-ray scattering (IXS), complementary to other more established inelastic scattering probes, such as light scattering, electron scattering, and neutron scattering, is becoming an important experimental technique in the study of elementary excitations in condensed matters. Over the past decade, IXS with total energy resolution of few meV has been achieved, and is being used routinely in the study of phonon dispersions in solids and liquids as well as dynamics in disordered and biological systems. In the study of electronic excitations, IXS with total energy resolution on the order of 100 meV to 1 eV is gaining wider applications also. For example, IXS has been used to study collective excitations of valence electrons, single electron excitations of valence electrons, as well as core electron excitations. In comparison with the alternative scattering techniques mentioned above, IXS has several advantages. First, IXS probes the full momentum transfer range of the dielectric response of the sample, whereas light scattering is limited to very small momentum transfers, and electron scattering suffers the effects of multiple scattering at large momentum transfers. Second, since IXS measures the bulk properties of the sample it is not surface sensitive, therefore it does not require special preparation of the sample. The greater flexibility in sample conditions and environments makes IXS an ideal probe in the study of liquids and samples under extreme temperature, pressure, and magnetic field. Third, the tunability of synchrotron radiation sources enables IXS to exploit element specificity and resonant enhancement of scattering cross sections. Fourth, IXS is unique in the study of dynamics of liquids and amorphous solids because it can probe the particular region of energy-momentum transfer phase space, which is inaccessible to inelastic neutron scattering. On the other hand, the main disadvantages of IXS are the small cross sections and the strong absorption of

Modeling X-Ray Scattering Process and Applications of the Scattering Model

Science.gov (United States)

Al-Jundi, Taher Lutfi

1995-01-01

Computer modeling of nondestructive inspections with x-rays is proving to be a very useful tool for enhancing the performance of these techniques. Two x-ray based inspection techniques are considered in this study. The first is "Radiographic Inspection", where an existing simulation model has been improved to account for scattered radiation effects. The second technique is "Inspection with Compton backscattering", where a new simulation model has been developed. The effect of scattered radiation on a simulated radiographic image can be insignificant, equally important, or more important than the effect of the uncollided flux. Techniques to account for the scattered radiation effects include Monte Carlo techniques, and solving the particle transport equation for photons. However, these two techniques although accurate, are computationally expensive and hence inappropriate for use in computer simulation of radiography. A less accurate approach but computationally efficient is the principle of buildup factors. Traditionally, buildup factors are defined for monoenergetic photons of energies typical of a nuclear reactor. In this work I have expanded the definition of buildup factors to include a bremsstrahlung spectrum of photons with energies typically used in radiography (keV's instead of MeV's). This expansion of the definition relies on an intensive experimental work to measure buildup factors for a white spectrum of x-rays. I have also developed a monte carlo code to reproduce the measured buildup factors. The code was then converted to a parallel code and distributed on a network of workstations to reduce the execution time. The second inspection technique is based on Compton backscattering, where photons are scattered at large angles, more than 90 degrees. The importance of this technique arises when the inspected object is very large, or when access is limited to only one side of the specimen. The downside of detecting photons from backscattering is the low

X-ray and neutron scattering studies of complex confined fluids

International Nuclear Information System (INIS)

Sinha, S. K.

1999-01-01

We review recent X-ray and neutron scattering studies of the structure and dynamics of confined complex fluids. This includes the study of polymer conformations and binary fluid phase transitions in porous media using Small Angle Neutron scattering, and the use of synchrotrons radiation to study ordering and fluctuation phenomena at solid/liquid and liquid/air interfaces. Ordering of liquids near a solid surface or in confinement will be discussed, and the study, via specular and off-specular X-ray reflectivity, of capillary wave fluctuations on liquid polymer films. Finally, we shall discuss the use of high-brilliance beams from X-ray synchrotrons to study via photon correlation spectroscopy the slow dynamics of soft condensed matter systems

X-ray crystal structure and small-angle X-ray scattering of sheep liver sorbitol dehydrogenase

Energy Technology Data Exchange (ETDEWEB)

Yennawar, Hemant [Pennsylvania State University, 8 Althouse Laboratory, University Park, PA 16802 (United States); Møller, Magda [Cornell High Energy Synchrotron Source, Ithaca, NY 14853 (United States); University of Copenhagen, DK-2100 Copenhagen (Denmark); Gillilan, Richard [Cornell High Energy Synchrotron Source, Ithaca, NY 14853 (United States); Yennawar, Neela, E-mail: nhy1@psu.edu [Pennsylvania State University, 8 Althouse Laboratory, University Park, PA 16802 (United States)

2011-05-01

The X-ray crystal structure and a small-angle X-ray scattering solution structure of sheep liver sorbitol dehydrogenase have been determined. The details of the interactions that enable the tetramer scaffold to be the functional biological unit have been analyzed. The X-ray crystal structure of sheep liver sorbitol dehydrogenase (slSDH) has been determined using the crystal structure of human sorbitol dehydrogenase (hSDH) as a molecular-replacement model. slSDH crystallized in space group I222 with one monomer in the asymmetric unit. A conserved tetramer that superposes well with that seen in hSDH (despite belonging to a different space group) and obeying the 222 crystal symmetry is seen in slSDH. An acetate molecule is bound in the active site, coordinating to the active-site zinc through a water molecule. Glycerol, a substrate of slSDH, also occupies the substrate-binding pocket together with the acetate designed by nature to fit large polyol substrates. The substrate-binding pocket is seen to be in close proximity to the tetramer interface, which explains the need for the structural integrity of the tetramer for enzyme activity. Small-angle X-ray scattering was also used to identify the quaternary structure of the tetramer of slSDH in solution.

X-ray scatter signatures for enhanced breast imaging

Energy Technology Data Exchange (ETDEWEB)

Kidane, Ghirmay; Speller, Robert; Royle, Gary [Medical Physics and Bioengineering Department, University College Landon, 11-20 Capper Street, London WC1E 6JA (United Kingdom)

1999-12-31

Conventional mammographic imaging suffers from a low specificity. The main cause is the small difference in the x-ray attenuation properties of healthy and diseased tissue leading to poor contrast in the image. It has been observed that additional information on breast tissue type can be obtained from x-ray diffraction effects. A study of excised normal and neoplastic breast tissue samples using x-ray diffraction apparatus has been observed that significant differences exist in the measured spectra between carcinoma and healthy tissue adjacent to the carcinoma. Such a difference allows tissue type to be characterised according to is diseased state. Furthermore the information can be applied to improve diagnosis. It is proposed that collection and analysis of the scattered x-rays present during a mammographic procedure can supply the additional information and be used to improve the image contrast. The ultimate aim of the project is to improve the specificity of x-ray mammography. (authors) 10 refs., 3 figs.

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

International Nuclear Information System (INIS)

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.

2015-01-01

A method of simulating X-ray diffuse scattering from multi-model PDB files is presented. Despite similar agreement with Bragg data, different translation–libration–screw refinement strategies produce unique diffuse intensity patterns. 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

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

Energy Technology Data Exchange (ETDEWEB)

Van Benschoten, Andrew H. [University of California San Francisco, San Francisco, CA 94158 (United States); Afonine, Pavel V. [Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Terwilliger, Thomas C.; Wall, Michael E. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Jackson, Colin J. [Australian National University, Canberra, ACT 2601 (Australia); Sauter, Nicholas K. [Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Adams, Paul D. [Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); University of California Berkeley, Berkeley, CA 94720 (United States); Urzhumtsev, Alexandre [Institut de Génétique et de Biologie Moléculaire et Cellulaire, CNRS–INSERM–UdS, 1 Rue Laurent Fries, BP 10142, 67404 Illkirch (France); Université de Lorraine, BP 239, 54506 Vandoeuvre-les-Nancy (France); Fraser, James S., E-mail: james.fraser@ucsf.edu [University of California San Francisco, San Francisco, CA 94158 (United States)

2015-07-28

A method of simulating X-ray diffuse scattering from multi-model PDB files is presented. Despite similar agreement with Bragg data, different translation–libration–screw refinement strategies produce unique diffuse intensity patterns. 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.

Small-angle X-ray scattering of solutions

International Nuclear Information System (INIS)

Koch, M.H.J.; Stuhrmann, H.B.; Vachette, P.; Tardieu, A.

1982-01-01

The use of synchrotron radiation in small-angle X-ray scattering (SAXS) techniques in biological structural studies is described. The main features of the monochromatic radiation systems and the white radiation systems are considered. The detectors, data acquisition and experimental procedures are briefly described. Experimental results are presented for 1) measurements on dilute solutions and weak scatterers, 2) measurement of conformational transitions, 3) contrast variation experiments, 4) time-resolved measurements and 5) complex contrast variation. (U.K.)

X-ray and neutron scattering from amorphous diamondlike carbon and hydrocarbon films

International Nuclear Information System (INIS)

Findeisen, E.

1994-10-01

In this report amorphous, diamondlike, carbon and hydrocarbon films are investigated by two different methods, namely, X-ray scattering and a combination of X-ray and neutron reflectivity. As specular reflectivity probes the scattering length density profile of a sample perpendicular to its surface, the combination of X-ray and neutron reflectivity reveals the nuclei density of both carbon and hydrogen separately. This allows to calculate the concentration of hydrogen in the films, which varies in the presented experiments between 0 and 36 atomic %. This method is a new and nondestructive technique to determine the concentration of hydrogen within an error of about ±1 at. % in samples with sharp interfaces. It is well suited for thin diamondlike carbon films. X-ray scattering is used to obtain structural information on the atomic scale, especially the average carbon-carbon distance and the average coordination number of the carbon atoms. As grazing incidence diffraction experiments were not successful, free-standing films are used for the scattering experiments with synchrotron light. However, the scattered intensity for large scattering vectors is, in spite of the intense primary beam, very weak, and therefore the accuracy of the obtained structural parameter is not sufficient to prove the diamondlike properties also on the atomic scale. (au) (10 tabs., 76 ills., 102 refs.)

Detectors for X-ray diffraction and scattering: a user's overview

International Nuclear Information System (INIS)

Bruegemann, Lutz; Gerndt, E.K.E.

2004-01-01

An overview of the applications of X-ray detectors to material research is given. Four experimental techniques and their specific detector requirements are described. Detector types are classified and critical parameters described in the framework of X-ray diffraction and X-ray scattering experiments. The article aims at building a bridge between detector end-users and detector developers. It gives limits of critical detector parameters, like angular resolution, energy resolution, dynamic range, and active area

Bone composition measured by x-ray scattering

International Nuclear Information System (INIS)

Newton, M.; Hukins, D.W.L.

1992-01-01

Ten composite samples consisting of cortical bone and adipose tissue, in known proportions, were made. The intensity of monochromatic x-rays (energy 8 keV) scattered by these samples was determined as a function of the modulus of the scattering vector, K. The ratio of the heights of peaks at K values of around 134 and 22 nm -1 provided a measure of the ratio of adipose tissue to bone mineral in these samples. This method was then used to determine the ratio of adipose tissue to mineral in samples of trabecular bone from 16 vertebral bodies. The results were correlated with measurements of the bone composition determined by ashing (r = 0.66) and histomorphometry (r = 0.66). Furthermore, the ashing and histomorphometry results were correlated with each other (r = 0.68). The feasibility of using higher energy x-rays (35-80 keV) for obtaining the same information from bone within the body is briefly discussed. (author)

Small-angle X-ray scattering studies of thermally-induced globular protein gels

International Nuclear Information System (INIS)

Clark, A.H.; Tuffnell, C.D.

1980-01-01

Small-angle X-ray scattering has been applied to gels formed by heating globular proteins, in aqueous solution, above their unfolding temperatures. A number of BSA gels, previously characterised by electron microscopy, have been studied, and by setting up theoretical models for the scattering process, the X-ray data have been shown to be consistent with the microscope conclusions regarding network structure. It is concluded that the networks form by a linearly-directed aggregation of unfolded, disc-like, protein molecules, three-dimensional geometry being achieved by occasional branching, and/or cross-linking. Long-range inhomogeneities in network structure, easily observed by electron microscopy, and correlated with variations in pH or ionic strength, have an effect on X-ray scattering, and hence the X-ray method is sensitive not only to different network strand thicknesses, but to different degrees of uniformity as well. (author)

X-ray scattering for the characterization of lyophilized breast tissue samples

International Nuclear Information System (INIS)

Elshemey, Wael M.; Mohamed, Fayrouz S.; Khater, Ibrahim M.

2013-01-01

This work investigates the possibility of characterizing breast cancer by measuring the X-ray scattering profiles of lyophilized excised breast tissue samples. Since X-ray scattering from water-rich tissue is dominated by scattering from water, the removal of water by lyophilization would enhance the characterization process. In the present study, X-ray scattering profiles of 22 normal, 22 malignant and 10 benign breast tissue samples are measured. The cut-offs of scatter diagrams, sensitivity, specificity and diagnostic accuracy of three characterization parameters (full width at half maximum (FWHM) for the peak at 1.1 nm −1 , area under curve (AUC), and ratio of 1st to 2nd scattering peak intensities (I 1 /I 2 %)) are calculated and compared to the data from non-lyophilized samples. Results show increased sensitivity (up to 100%) of the present data on lyophilized breast tissue samples compared to previously reported data for non-lyophilized samples while the specificity (up to 95.4%), diagnostic accuracy (up to 95.4%) and receiver operating characteristic (ROC) curve values (up to 0.9979) for both sets of data are comparable. The present study shows significant differences between normal samples and each of malignant and benign samples. Only subtle differences exist between malignant and benign lyophilized breast tissue samples where FWHM=0.7±0.1 and 0.8±0.3, AUC=1.3±0.2 and 1.4±0.2 and I 1 /I 2 %=44.9±11.0 and 52.4±7.6 for malignant and benign samples respectively. - Highlights: • X-ray scattering profiles of breast tissue samples are acquired. • Three X-ray profile characterization parameters are calculated. • The cut-offs, sensitivity, specificity and diagnostic accuracy are calculated. • They are compared to the data from non-lyophilized samples. • Results show increased sensitivity in case of lyophilized samples

Incoherent-scatter computed tomography with monochromatic synchrotron x ray: feasibility of multi-CT imaging system for simultaneous measurement-of fluorescent and incoherent scatter x rays

Science.gov (United States)

Yuasa, T.; Akiba, M.; Takeda, T.; Kazama, M.; Hoshino, A.; Watanabe, Y.; Hyodo, K.; Dilmanian, F. A.; Akatsuka, T.; Itai, Y.

1997-10-01

We describe a new system of incoherent scatter computed tomography (ISCT) using monochromatic synchrotron X rays, and we discuss its potential to be used in in vivo imaging for medical use. The system operates on the basis of computed tomography (CT) of the first generation. The reconstruction method for ISCT uses the least squares method with singular value decomposition. The research was carried out at the BLNE-5A bending magnet beam line of the Tristan Accumulation Ring in KEK, Japan. An acrylic cylindrical phantom of 20-mm diameter containing a cross-shaped channel was imaged. The channel was filled with a diluted iodine solution with a concentration of 200 /spl mu/gI/ml. Spectra obtained with the system's high purity germanium (HPGe) detector separated the incoherent X-ray line from the other notable peaks, i.e., the iK/sub /spl alpha// and K/sub /spl beta/1/ X-ray fluorescent lines and the coherent scattering peak. CT images were reconstructed from projections generated by integrating the counts In the energy window centering around the incoherent scattering peak and whose width was approximately 2 keV. The reconstruction routine employed an X-ray attenuation correction algorithm. The resulting image showed more homogeneity than one without the attenuation correction.

Propagation and scattering of high-intensity X-ray pulses in dense atomic gases and plasmas

International Nuclear Information System (INIS)

Weninger, Clemens

2015-10-01

Nonlinear spectroscopy in the X-ray domain is a promising technique to explore the dynamics of elementary excitations in matter. X-rays provide an element specificity that allows them to target individual chemical elements, making them a great tool to study complex molecules. The recent advancement of X-ray free electron lasers (XFELs) allows to investigate non-linear processes in the X-ray domain for the first time. XFELs provide short femtosecond X-ray pulses with peak powers that exceed previous generation synchrotron X-ray sources by more than nine orders of magnitude. This thesis focuses on the theoretical description of stimulated emission processes in the X-ray regime in atomic gases. These processes form the basis for more complex schemes in molecules and provide a proof of principle for nonlinear X-ray spectroscopy. The thesis also includes results from two experimental campaigns at the Linac Coherent Light Source and presents the first experimental demonstration of stimulated X-ray Raman scattering. Focusing an X-ray free electron laser beam into an elongated neon gas target generates an intense stimulated X-ray emission beam in forward direction. If the incoming X-rays have a photon energy above the neon K edge, they can efficiently photo-ionize 1s electrons and generate short-lived core excited states. The core-excited states decay mostly via Auger decay but have a small probability to emit a spontaneous X-ray photon. The spontaneous emission emitted in forward direction can stimulate X-ray emission along the medium and generate a highly directional and intense X-ray laser pulse. If the photon energy of the incoming X-rays however is below the ionization edge in the region of the pre-edge resonance the incoming X-rays can be inelastically scattered. This spontaneous X-ray Raman scattering process has a very low probability, but the spontaneously scattered photons in the beginning of the medium can stimulate Raman scattering along the medium. The

Development of a compact x-ray source via laser compton scattering at KEK-LUCX

International Nuclear Information System (INIS)

Sakaue, Kazuyuki; Washio, Masakazu; Aryshev, Alexander; Araki, Sakae; Urakawa, Junji; Terunuma, Nobuhiro; Fukuda, Masafumi; Miyoshi, Toshinobu; Takeda, Ayaki

2013-01-01

The compact X-ray source based on Laser-Compton scattering (LCS) has been developed at LUCX (Laser Undulator Compact X-ray source) facility in KEK. The multi-bunch high quality electron beam produced by a standing wave 3.6 cell RF Gun and accelerated by the followed S-band normal conducting 12 cells standing wave 'Booster' linear accelerator is scattered off the laser beam stored in the optical cavity. The 4-mirror planar optical cavity with finesse 335 is used. The MCP (Micro-Channer Plate) detector as well as SOI (Silicon-On-Insulator) pixel sensor was used for scattered X-ray detection. The SOI pixel sensor has been used for LCS X-ray detection for the first time and has demonstrated high spatial resolution and high SN ratio X-ray detection that in turn lead to clearest X-ray images achieved by LCS X-ray. We have also achieved generation of 6.38x10 6 ph./sec., which is more than 30 times larger LCS X-ray flux in comparison with our previous results. The complete details of LUCX LCS X-ray source, specifications of both electron and laser beams, and the results of LCS X-ray generation experiments are reported in this paper. (author)

High energy x-ray scattering studies of strongly correlated oxides

International Nuclear Information System (INIS)

Hatton, Peter D; Wilkins, S B; Spencer, P D; Zimmermann, M v; D'Almeida, T

2003-01-01

Many transition metal oxides display strongly correlated charge, spin, or orbital ordering resulting in varied phenomena such as colossal magnetoresistance, high temperature superconductivity, metal-insulator transitions etc. X-ray scattering is one of the principle techniques for probing the structural response to such effects. In this paper, we discuss and review the use of synchrotron radiation high energy x-rays (50-200 keV) for the study of transition metal oxides such as nickelates (La 2-x Sr x NiO 4 ) and manganites (La 2-2x Sr 1+2x Mn 2 O 7 ). High energy x-rays have sufficient penetration to allow us to study large flux-grown single crystals. The huge increase in sample scattering volume means that extremely weak peaks can be observed. This allows us to study very weak charge ordering. Measurements of the intensity, width and position of the charge ordering satellites as a function of temperature provide us with quantitative measures of the charge amplitude, inverse correlation length and wavevector of the charge ordering

Studies of oxide-based thin-layered heterostructures by X-ray scattering methods

Energy Technology Data Exchange (ETDEWEB)

Durand, O. [Thales Research and Technology France, Route Departementale 128, F-91767 Palaiseau Cedex (France)]. E-mail: olivier.durand@thalesgroup.com; Rogers, D. [Nanovation SARL, 103 bis rue de Versailles 91400 Orsay (France); Universite de Technologie de Troyes, 10-12 rue Marie Curie, 10010 (France); Teherani, F. Hosseini [Nanovation SARL, 103 bis rue de Versailles 91400 Orsay (France); Andrieux, M. [LEMHE, ICMMOCNRS-UMR 8182, Universite d' Orsay, Batiment 410, 91410 Orsay (France); Modreanu, M. [Tyndall National Institute, Lee Maltings, Prospect Row, Cork (Ireland)

2007-06-04

Some X-ray scattering methods (X-ray reflectometry and Diffractometry) dedicated to the study of thin-layered heterostructures are presented with a particular focus, for practical purposes, on the description of fast, accurate and robust techniques. The use of X-ray scattering metrology as a routinely working non-destructive testing method, particularly by using procedures simplifying the data-evaluation, is emphasized. The model-independent Fourier-inversion method applied to a reflectivity curve allows a fast determination of the individual layer thicknesses. We demonstrate the capability of this method by reporting X-ray reflectometry study on multilayered oxide structures, even when the number of the layers constitutive of the stack is not known a-priori. Fast Fourier transform-based procedure has also been employed successfully on high resolution X-ray diffraction profiles. A study of the reliability of the integral-breadth methods in diffraction line-broadening analysis applied to thin layers, in order to determine coherent domain sizes, is also reported. Examples from studies of oxides-based thin-layers heterostructures will illustrate these methods. In particular, X-ray scattering studies performed on high-k HfO{sub 2} and SrZrO{sub 3} thin-layers, a (GaAs/AlOx) waveguide, and a ZnO thin-layer are reported.

Quantitative Characterization of Configurational Space Sampled by HIV-1 Nucleocapsid Using Solution NMR, X-ray Scattering and Protein Engineering.

Science.gov (United States)

Deshmukh, Lalit; Schwieters, Charles D; Grishaev, Alexander; Clore, G Marius

2016-06-03

Nucleic-acid-related events in the HIV-1 replication cycle are mediated by nucleocapsid, a small protein comprising two zinc knuckles connected by a short flexible linker and flanked by disordered termini. Combining experimental NMR residual dipolar couplings, solution X-ray scattering and protein engineering with ensemble simulated annealing, we obtain a quantitative description of the configurational space sampled by the two zinc knuckles, the linker and disordered termini in the absence of nucleic acids. We first compute the conformational ensemble (with an optimal size of three members) of an engineered nucleocapsid construct lacking the N- and C-termini that satisfies the experimental restraints, and then validate this ensemble, as well as characterize the disordered termini, using the experimental data from the full-length nucleocapsid construct. The experimental and computational strategy is generally applicable to multidomain proteins. Differential flexibility within the linker results in asymmetric motion of the zinc knuckles which may explain their functionally distinct roles despite high sequence identity. One of the configurations (populated at a level of ≈40 %) closely resembles that observed in various ligand-bound forms, providing evidence for conformational selection and a mechanistic link between protein dynamics and function. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

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

International Nuclear Information System (INIS)

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

2015-01-01

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

Magnetism in heterogeneous thin film systems: Resonant X-ray scattering studies

International Nuclear Information System (INIS)

Kortright, J.B.; Jiang, J.S.; Bader, S.D.; Hellwig, O.; Marguiles, D.T.; Fullerton, E.E.

2002-01-01

Magnetic and chemical heterogeneity are common in a broad range of magnetic thin film systems. Emerging resonant soft x-ray scattering techniques are well suited to resolve such heterogeneity at relevant length scales. Resonant x-ray magneto-optical Kerr effect measurements laterally average over heterogeneity but can provide depth resolution in different ways, as illustrated in measurements resolving reversible and irreversible changes in different layers of exchange-spring heterostructures. Resonant small-angle scattering measures in-plane heterogeneity and can resolve magnetic and chemical scattering sources in different ways, as illustrated in measurements of granular alloy recording media

PREFACE: Structure and dynamics determined by neutron and x-ray scattering Structure and dynamics determined by neutron and x-ray scattering

Science.gov (United States)

Müller-Buschbaum, Peter

2011-06-01

Neutron and x-ray scattering have emerged as powerful methods for the determination of structure and dynamics. Driven by emerging new, powerful neutron and synchrotron radiation sources, the continuous development of new instrumentation and novel scattering techniques gives rise to exciting possibilities. For example, in situ observations become possible via a high neutron or x-ray flux at the sample and, as a consequence, morphological transitions with small time constants can be detected. This special issue covers a broad range of different materials from soft to hard condensed matter. Hence, different material classes such as colloids, polymers, alloys, oxides and metals are addressed. The issue is dedicated to the 60th birthday of Professor Winfried Petry, scientific director of the Research Neutron Source Heinz Maier-Leibnitz (FRM-II), Germany, advisor at the physics department for the Bayerische Elite-Akademie, chair person of the Arbeitsgemeinschaft Metall- und Materialphysik of the German Physical Society (DPG) and a member of the professional council of the German Science Foundation (Deutsche Forschungsgemeinschaft, DFG). We would like to acknowledge and thank all contributors for their submissions, which made this special issue possible in the first place. Moreover, we would like to thank the staff at IOP Publishing for helping us with the administrative aspects and for coordinating the refereeing process, and Valeria Lauter for the beautiful cover artwork. Finally, to the readers, we hope that you find this special issue a valuable resource that provides insights into the present possibilities of neutron and x-ray scattering as powerful tools for the investigation of structure and dynamics. Structure and dynamics determined by neutron and x-ray scattering contents In situ studies of mass transport in liquid alloys by means of neutron radiography F Kargl, M Engelhardt, F Yang, H Weis, P Schmakat, B Schillinger, A Griesche and A Meyer Magnetic spin

K-α X-ray Thomson Scattering From Dense Plasmas

International Nuclear Information System (INIS)

Kritcher, Andrea L.; Neumayer, Paul; Castor, John; Doeppner, Tilo; Landen, Otto L.; Ng, Andrew; Pollaine, Steve; Price, Dwight; Glenzer, Siegfried H.; Falcone, Roger W.; Ja Lee, Hae; Lee, Richard W.; Morse, Edward C.

2009-01-01

Spectrally resolved Thomson scattering using ultra-fast K-α x rays has measured the compression and heating of shocked compressed matter. The evolution and coalescence of two shock waves traveling through a solid density LiH target were characterized by the elastic scattering component. The density and temperature at shock coalescence, 2.2 eV and 1.7x10 23 cm -3 , were determined from the plasmon frequency shift and the relative intensity of the elastic and inelastic scattering features in the collective scattering regime. The observation of plasmon scattering at coalescence indicates a transition to the dense metallic state in LiH. The density and temperature regimes accessed in these experiments are relevant for inertial confinement fusion experiments and for the study of planetary formation.

K-(alpha) X-ray Thomson Scattering From Dense Plasmas

International Nuclear Information System (INIS)

Kritcher, A.L.; Neumayer, P.; Castor, J.; Doppner, T.; Falcone, R.W.; Landen, O.L.; Lee, H.J.; Lee, R.W.; Morse, E.C.; Ng, A.; Pollaine, S.; Price, D.; Glenzer, S.H.

2009-01-01

Spectrally resolved Thomson scattering using ultra-fast K-α x-rays has measured the compression and heating of shocked compressed matter. The evolution and coalescence of two shock waves traveling through a solid density LiH target were characterized by the elastic scattering component. The density and temperature at shock coalescence, 2.2 eV and 1.7 x 10 23 cm -3 , were determined from the plasmon frequency shift and the relative intensity of the elastic and inelastic scattering features in the collective scattering regime. The observation of plasmon scattering at coalescence indicates a transition to the dense metallic state in LiH. The density and temperature regimes accessed in these experiments are relevant for inertial confinement fusion experiments and for the study of planetary formation

Ultrashort hard x-ray pulses generated by 90 degrees Thomson scattering

International Nuclear Information System (INIS)

Chin, A.H.; Schoenlein, R.W.; Glover, T.E.

1997-01-01

Ultrashort x-ray pulses permit observation of fast structural dynamics in a variety of condensed matter systems. The authors have generated 300 femtosecond, 30 keV x-ray pulses by 90 degrees Thomson scattering between femtosecond laser pulses and relativistic electrons. The x-ray and laser pulses are synchronized on a femtosecond time scale, an important prerequisite for ultrafast pump-probe spectroscopy. Analysis of the x-ray beam properties also allows for electron bunch characterization on a femtosecond time scale

Multiple X-ray tomography using transmitted, scattered and fluorescent radiation

International Nuclear Information System (INIS)

Cesareo, R.; Brunetti, A.; Golosio, B.; Lopes, R.T.; Barroso, R.C.; Donativi, M.; Castellano, A.; Quarta, S.

2003-01-01

A multiple CT-scanner is described, which contemporaneously uses transmitted, scattered and fluorescent X-rays for Imaging. The scanner is characterized by a small size X-ray tube and by four detectors: a ''pencil'' X-ray NaI(Tl) for transmitted tomography, a larger size NaI(Tl) for 90 C o Compton tomography, a thermoelectrically cooled Si-PIN or CdZnTe for fluorescent imaging and a CdZnTe for Rayleigh (or diffraction) tomography. Examples of applications are shown

Soft X-ray resonant scattering from magnetic heterostructures

International Nuclear Information System (INIS)

Grabis, J.

2005-01-01

Heterogenous magnetic multilayers are of great interest both because of their relevance for technological applications and since they provide model systems to understand magnetic behavior and interactions. Soft x-ray resonant magnetic scattering (XRMS) allows to determine element-specific and depth-resolving information of the local magnetic order of such systems. Within the framework of the present thesis the diffractometer ALICE for soft XRMS has been constructed. XRMS measurements of two different physical systems are presented in this thesis: The antiferromagnetic and ferromagnetic order in interlayer exchange-coupled Fe/Cr(001) superlattices are studied as a function of the applied field by measuring the reflected intensity at different positions in reciprocal space. Thin films and multilayers of the Heusler compound Co 2 MnGe are studied by means of soft x-ray absorption spectroscopy, magnetic circular dichroism and resonant magnetic scattering

Measurement of scattered and transmitted X-rays from intra-oral and panoramic dental X-ray equipment.

Science.gov (United States)

Holroyd, John Richard

2018-04-10

To quantify the levels of transmitted radiation arising from the use of intra-oral dental X-ray equipment and scattered radiation arising from the use of both intra-oral and panoramic X-ray equipment. Methods: Levels of scattered radiation were measured at 1 m from a phantom, using an 1800 cc ion chamber. Transmitted radiation was measured using both: i) a phantom and Dose Area Product (DAP) meter, ii) a patient and an 1800 cc ion chamber. Results: For intra-oral radiography the patient study gave a maximum transmission of 1.80% (range 0.04% to 1.80%, mean 0.26%) and the phantom study gave a maximum transmission of 6% (range 2% to 6%, mean 5%). The maximum scattered radiation, per unit DAP, was 5.5 nGy (mGy cm2)-1 at 70 kVp and a distance of 1 m. For panoramic radiography the maximum scattered radiation was 9.3 nGy (mGy cm2)-1 at 80 kVp and a distance of 1 m. Conclusions: Typical doses from scattered and transmitted radiation in modern dental practice have been measured and values are presented to enable the calculation of adequate protection measures for dental radiography rooms. Advances in knowledge: Previous studies have used a phantom and measured radiation doses at 1 m from the phantom to determine the radiation dose transmitted through a patient, whereas this study uses both patient and phantom measurements together with a large area dose meter, positioned to capture the entire X-ray beam, to ensure more realistic dose measurements can be made. © 2018 IOP Publishing Ltd.

X-Band Linac Beam-Line for Medical Compton Scattering X-Ray Source

CERN Document Server

Dobashi, Katsuhiro; Ebina, Futaro; Fukasawa, Atsushi; Hayano, Hitoshi; Higo, Toshiyasu; Kaneyasu, Tatsuo; Ogino, Haruyuki; Sakamoto, Fumito; Uesaka, Mitsuru; Urakawa, Junji; Yamamoto, Tomohiko

2005-01-01

Compton scattering hard X-ray source for 10~80 keV are under construction using the X-band (11.424 GHz) electron linear accelerator and YAG laser at Nuclear Engineering Research laboratory, University of Tokyo. This work is a part of the national project on the development of advanced compact medical accelerators in Japan. National Institute for Radiological Science is the host institute and U. Tokyo and KEK are working for the X-ray source. Main advantage is to produce tunable monochromatic hard ( 10-80

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

International Nuclear Information System (INIS)

Macrander, A.T.

1996-08-01

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

Experiment and application of soft x-ray grazing incidence optical scattering phenomena

Science.gov (United States)

Chen, Shuyan; Li, Cheng; Zhang, Yang; Su, Liping; Geng, Tao; Li, Kun

2017-08-01

For short wavelength imaging systems，surface scattering effects is one of important factors degrading imaging performance. Study of non-intuitive surface scatter effects resulting from practical optical fabrication tolerances is a necessary work for optical performance evaluation of high resolution short wavelength imaging systems. In this paper, Soft X-ray optical scattering distribution is measured by a soft X-ray reflectometer installed by my lab, for different sample mirrors、wavelength and grazing angle. Then aim at space solar telescope, combining these scattered light distributions, and surface scattering numerical model of grazing incidence imaging system, PSF and encircled energy of optical system of space solar telescope are computed. We can conclude that surface scattering severely degrade imaging performance of grazing incidence systems through analysis and computation.

Fast scattering simulation tool for multi-energy x-ray imaging

Energy Technology Data Exchange (ETDEWEB)

Sossin, A., E-mail: artur.sossin@cea.fr [CEA-LETI MINATEC Grenoble, F-38054 Grenoble (France); Tabary, J.; Rebuffel, V. [CEA-LETI MINATEC Grenoble, F-38054 Grenoble (France); Létang, J.M.; Freud, N. [Université de Lyon, CREATIS, CNRS UMR5220, Inserm U1044, INSA-Lyon, Université Claude Bernard Lyon 1, Centre Léon Bérard (France); Verger, L. [CEA-LETI MINATEC Grenoble, F-38054 Grenoble (France)

2015-12-01

A combination of Monte Carlo (MC) and deterministic approaches was employed as a means of creating a simulation tool capable of providing energy resolved x-ray primary and scatter images within a reasonable time interval. Libraries of Sindbad, a previously developed x-ray simulation software, were used in the development. The scatter simulation capabilities of the tool were validated through simulation with the aid of GATE and through experimentation by using a spectrometric CdTe detector. A simple cylindrical phantom with cavities and an aluminum insert was used. Cross-validation with GATE showed good agreement with a global spatial error of 1.5% and a maximum scatter spectrum error of around 6%. Experimental validation also supported the accuracy of the simulations obtained from the developed software with a global spatial error of 1.8% and a maximum error of around 8.5% in the scatter spectra.

Resonant Soft X-ray Scattering of Cellulose Microstructure in Plant Primary Cell Walls

Science.gov (United States)

Ye, Dan; Kiemle, Sarah N.; Wang, Cheng; Cosgrove, Daniel J.; Gomez, Esther W.; Gomez, Enrique D.

Cellulosic biomass is the most abundant raw material available for the production of renewable and sustainable biofuels. Breaking down cellulose is the rate-limiting step in economical biofuel production; therefore, a detailed understanding of the microscopic structure of plant cell walls is required to develop efficient biofuel conversion methods. Primary cell walls are key determinants of plant growth and mechanics. Their structure is complex and heterogeneous, making it difficult to elucidate how various components such as pectin, hemicellulose, and cellulose contribute to the overall structure. The electron density of these wall components is similar; such that conventional hard X-ray scattering does not generate enough contrast to resolve the different elements of the polysaccharide network. The chemical specificity of resonant soft X-ray scattering allows contrast to be generated based on differences in chemistry of the different polysaccharides. By varying incident X-ray energies, we have achieved increased scattering contrast between cellulose and other polysaccharides from primary cell walls of onions. By performing scattering at certain energies, features of the network structure of the cell wall are resolved. From the soft X-ray scattering results, we obtained the packing distance of cellulose microfibrils embedded in the polysaccharide network.

X-ray scattering from thin organic films and multilayer

International Nuclear Information System (INIS)

Pietsch, U.; Barberka, T. A.; Geue, Th.; Stoemmer, R.

1997-01-01

The real structure of LB-multilayers prepared with fatty-acid salts is dominated by finite-sized scattering aggregates. Their different length scales become visible using AFM. It shows that not the whole substrate is wetted by the film. The molecular order is restricted into domains. These micrometer domains are not homogeneous. They contain mesoscopic subdomains of different heights which vary in steps of double layers. Finally high-resolution AFM-maps display a nearly hexagonal arrangement of molecules within subgrains with a diameter of several 10 nm. This domain structure has to be taken into account when interpreting X-ray diffraction data. The size of the crystalline aggregates is obtained by means of X-ray grazing incidence diffraction. On the mesoscopic scale the domain size is determined by X-ray diffuse scattering experiments. Because Sinha's model fails for the present kind of multilayers, they used another approach for data analysis. The lateral correlation length caused by height fluctuations is estimated without knowledge of a definite correlation function. Additionally the mosaicity of the domain orientation can be taken into account

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

International Nuclear Information System (INIS)

Iwazumi, Toshiaki

2004-01-01

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

Determination of X-ray anomalous scattering in silicon

International Nuclear Information System (INIS)

Cusatis, C.

1987-01-01

The linear attenuation coeficient for X-ray in silicon was measured with approximately 0,1% accuracy, for 6 diferent wavelenghts of caracteristic radiation. From these result the imaginary parts of the atomic scattering factors, for silicon and for those wavelenghts, were obtained with the same accuracy. The results are compared with the most recent published values. The proposed method to avoid Rayleigh scattering can be used for any type of ''perfect'' crystal. (author) [pt

FDTD parallel computational analysis of grid-type scattering filter characteristics for medical X-ray image diagnosis

International Nuclear Information System (INIS)

Takahashi, Koichi; Miyazaki, Yasumitsu; Goto, Nobuo

2007-01-01

X-ray diagnosis depends on the intensity of transmitted and scattered waves in X-ray propagation in biomedical media. X-ray is scattered and absorbed by tissues, such as fat, bone and internal organs. However, image processing for medical diagnosis, based on the scattering and absorption characteristics of these tissues in X-ray spectrum is not so much studied. To obtain precise information of tissues in a living body, the accurate characteristics of scattering and absorption are required. In this paper, X-ray scattering and absorption in biomedical media are studied using 2-dimensional finite difference time domain (FDTD) method. In FDTD method, the size of analysis space is very limited by the performance of available computers. To overcome this limitation, parallel and successive FDTD method is introduced. As a result of computer simulation, the amplitude of transmitted and scattered waves are presented numerically. The fundamental filtering characteristics of grid-type filter are also shown numerically. (author)

Simultaneous use of solution NMR and X-ray data in REFMAC5 for joint refinement/detection of structural differences

Energy Technology Data Exchange (ETDEWEB)

Rinaldelli, Mauro; Ravera, Enrico; Calderone, Vito; Parigi, Giacomo [University of Florence, Via L. Sacconi 6, 50019 Sesto Fiorentino (Finland) (Italy); University of Florence, Via della Lastruccia 3, 50019 Sesto Fiorentino (Finland) (Italy); Murshudov, Garib N., E-mail: garib@mrc-lmb.cam.ac.uk [MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge Biomedical Campus, Cambridge CB2 0QH (United Kingdom); Luchinat, Claudio, E-mail: garib@mrc-lmb.cam.ac.uk [University of Florence, Via L. Sacconi 6, 50019 Sesto Fiorentino (Finland) (Italy); University of Florence, Via della Lastruccia 3, 50019 Sesto Fiorentino (Finland) (Italy)

2014-04-01

Paramagnetic NMR data (pseudocontact shifts and self-orientation residual dipolar couplings) and diamagnetic residual dipolar couplings can now be used in the program REFMAC5 from CCP4 as structural restraints together with X-ray crystallographic data. These NMR restraints can reveal differences between solid state and solution conformations of molecules or, in their absence, can be used together with X-ray crystallographic data for structural refinement. The program REFMAC5 from CCP4 was modified to allow the simultaneous use of X-ray crystallographic data and paramagnetic NMR data (pseudocontact shifts and self-orientation residual dipolar couplings) and/or diamagnetic residual dipolar couplings. Incorporation of these long-range NMR restraints in REFMAC5 can reveal differences between solid-state and solution conformations of molecules or, in their absence, can be used together with X-ray crystallographic data for structural refinement. Since NMR and X-ray data are complementary, when a single structure is consistent with both sets of data and still maintains reasonably ‘ideal’ geometries, the reliability of the derived atomic model is expected to increase. The program was tested on five different proteins: the catalytic domain of matrix metalloproteinase 1, GB3, ubiquitin, free calmodulin and calmodulin complexed with a peptide. In some cases the joint refinement produced a single model consistent with both sets of observations, while in other cases it indicated, outside the experimental uncertainty, the presence of different protein conformations in solution and in the solid state.

Simultaneous use of solution NMR and X-ray data in REFMAC5 for joint refinement/detection of structural differences

International Nuclear Information System (INIS)

Rinaldelli, Mauro; Ravera, Enrico; Calderone, Vito; Parigi, Giacomo; Murshudov, Garib N.; Luchinat, Claudio

2014-01-01

Paramagnetic NMR data (pseudocontact shifts and self-orientation residual dipolar couplings) and diamagnetic residual dipolar couplings can now be used in the program REFMAC5 from CCP4 as structural restraints together with X-ray crystallographic data. These NMR restraints can reveal differences between solid state and solution conformations of molecules or, in their absence, can be used together with X-ray crystallographic data for structural refinement. The program REFMAC5 from CCP4 was modified to allow the simultaneous use of X-ray crystallographic data and paramagnetic NMR data (pseudocontact shifts and self-orientation residual dipolar couplings) and/or diamagnetic residual dipolar couplings. Incorporation of these long-range NMR restraints in REFMAC5 can reveal differences between solid-state and solution conformations of molecules or, in their absence, can be used together with X-ray crystallographic data for structural refinement. Since NMR and X-ray data are complementary, when a single structure is consistent with both sets of data and still maintains reasonably ‘ideal’ geometries, the reliability of the derived atomic model is expected to increase. The program was tested on five different proteins: the catalytic domain of matrix metalloproteinase 1, GB3, ubiquitin, free calmodulin and calmodulin complexed with a peptide. In some cases the joint refinement produced a single model consistent with both sets of observations, while in other cases it indicated, outside the experimental uncertainty, the presence of different protein conformations in solution and in the solid state

Ion chamber area monitor for low level scattered x-rays

International Nuclear Information System (INIS)

Fergus, R.W.; Robinet, M.J.

1978-01-01

An economical, high confidence instrument was developed for laboratories using low energy x-rays. The instrument detects increases in background caused by scattered radiation. Exposure rates close to the open part of the x-ray tubes are of the order of 10 3 to 10 6 R/min. A few meters away the background is a few tenths of a mR/hr

X-ray spectral determination by detection of radiation scattered at different angles

International Nuclear Information System (INIS)

Barrea, Raul; Mainardi, R.T.

1987-01-01

A precise knowledge of the spectral content of an X-ray beam is of fundamental importance in areas such as X-ray fluorescence analysis by absolute methods, radiodiagnosis, radiotherapy, computed tomography, etc. A simple practical method was developed to determine X-ray spectra emitted by X-ray tubes. It is based on the scattering of the beam on a solid target and detection of this radiation at different angles. This methodology can easily be adapted to the successive attenuation of the beam procedure. Numerical parameter values of a proposed analytical function for the energy spectrum are found measuring the radiation intensity with a suitable detector (ionization chamber or plastic scintillation detector) and equating it with the convolution integral of the proposed spectrum with the incoherent scattering function. This procedure of spectra determination is enclosed in the same group of those generically referred as successive modifications of the irradiation set up used in absolute methods of X-ray fluorescence analysis. (Author) [es

X-band RF gun and linac for medical Compton scattering X-ray source

International Nuclear Information System (INIS)

Dobashi, Katsuhito; Uesaka, Mitsuru; Fukasawa, Atsushi; Sakamoto, Fumito; Ebina, Futaro; Ogino, Haruyuki; Urakawa, Junji; Higo, Toshiyasu; Akemoto, Mitsuo; Hayano, Hitoshi; Nakagawa, Keiichi

2004-01-01

Compton scattering hard X-ray source for 10-80 keV are under construction using the X-band (11.424 GHz) electron linear accelerator and YAG laser at Nuclear Engineering Research laboratory, University of Tokyo. This work is a part of the national project on the development of advanced compact medical accelerators in Japan. National Institute for Radiological Science is the host institute and U.Tokyo and KEK are working for the X-ray source. Main advantage is to produce tunable monochromatic hard (10-80 keV) X-rays with the intensities of 108-1010 photons/s (at several stages) and the table-top size. Second important aspect is to reduce noise radiation at a beam dump by adopting the deceleration of electrons after the Compton scattering. This realizes one beamline of a 3rd generation SR source at small facilities without heavy shielding. The final goal is that the linac and laser are installed on the moving gantry. We have designed the X-band (11.424 GHz) traveling-wave-type linac for the purpose. Numerical consideration by CAIN code and luminosity calculation are performed to estimate the X-ray yield. X-band thermionic-cathode RF-gun and RDS(Round Detuned Structure)-type X-band accelerating structure are applied to generate 50 MeV electron beam with 20 pC microbunches (104) for 1 microsecond RF macro-pulse. The X-ray yield by the electron beam and Q-switch Nd:YAG laser of 2 J/10 ns is 107 photons/RF-pulse (108 photons/sec at 10 pps). We design to adopt a technique of laser circulation to increase the X-ray yield up to 109 photons/pulse (1010 photons/s). 50 MW X-band klystron and compact modulator have been constructed and now under tuning. The construction of the whole system has started. X-ray generation and medical application will be performed in the early next year

X-band RF gun and linac for medical Compton scattering X-ray source

Science.gov (United States)

Dobashi, Katsuhito; Uesaka, Mitsuru; Fukasawa, Atsushi; Sakamoto, Fumito; Ebina, Futaro; Ogino, Haruyuki; Urakawa, Junji; Higo, Toshiyasu; Akemoto, Mitsuo; Hayano, Hitoshi; Nakagawa, Keiichi

2004-12-01

Compton scattering hard X-ray source for 10-80 keV are under construction using the X-band (11.424 GHz) electron linear accelerator and YAG laser at Nuclear Engineering Research laboratory, University of Tokyo. This work is a part of the national project on the development of advanced compact medical accelerators in Japan. National Institute for Radiological Science is the host institute and U.Tokyo and KEK are working for the X-ray source. Main advantage is to produce tunable monochromatic hard (10-80 keV) X-rays with the intensities of 108-1010 photons/s (at several stages) and the table-top size. Second important aspect is to reduce noise radiation at a beam dump by adopting the deceleration of electrons after the Compton scattering. This realizes one beamline of a 3rd generation SR source at small facilities without heavy shielding. The final goal is that the linac and laser are installed on the moving gantry. We have designed the X-band (11.424 GHz) traveling-wave-type linac for the purpose. Numerical consideration by CAIN code and luminosity calculation are performed to estimate the X-ray yield. X-band thermionic-cathode RF-gun and RDS(Round Detuned Structure)-type X-band accelerating structure are applied to generate 50 MeV electron beam with 20 pC microbunches (104) for 1 microsecond RF macro-pulse. The X-ray yield by the electron beam and Q-switch Nd:YAG laser of 2 J/10 ns is 107 photons/RF-pulse (108 photons/sec at 10 pps). We design to adopt a technique of laser circulation to increase the X-ray yield up to 109 photons/pulse (1010 photons/s). 50 MW X-band klystron and compact modulator have been constructed and now under tuning. The construction of the whole system has started. X-ray generation and medical application will be performed in the early next year.

X-ray scattering from surfaces of organic crystals

DEFF Research Database (Denmark)

Gidalevitz, D.; Feidenhans'l, R.; Smilgies, D.-M.

1997-01-01

X-ray scattering experiments have been performed on the surfaces of organic crystals. The (010) cleavage planes of beta-alanine and alpha-glycine were investigated, and both specular and off-specular crystal truncation rods were measured. This allowed a determination of the molecular layering...

Experimental elucidation: microscopic mechanism of resonant X-ray scattering in manganite films

CERN Document Server

Ohsumi, H; Kiyama, T

2003-01-01

Resonant X-ray scattering experiments have been performed on perovskite manganite La sub 0 sub . sub 5 Sr sub 0 sub . sub 5 MnO sub 3 thin films, which are grown on three distinct perovskite with a coherent epitaxial strain and have a forced ferro-type orbital ordering of Mn 3d orbitals. Using an interference technique, we have successfully observed the resonant X-ray scattering signal from the system having the ferro-type orbital ordering and also revealed the energy scheme of Mn 4p bands. For the forced ferro-type orbital ordering system, the present results evidence that the resonant X-ray scattering signal originates from the band structure effect due to the Jahn-Teller distortion of a MnO sub 6 octahedron, and not from the Coulomb interaction between 3d and 4p electrons. (author)

Precise tests of x-ray scattering theories in the Compton regime

International Nuclear Information System (INIS)

Dunford, R. W.; Gemmell, D. S.; Kanter, E. P.; Kraessig, B.; Southworth, S. H.; Young, L.

1999-01-01

The authors report two experiments intended to test the accuracy of state-of-the-art theoretical predictions for x-ray scattering from low-Z atoms. The first one deals with the differential x-ray scattering cross sections in Ne and He from 11-22 keV and the Ne Compton-to-Rayleigh scattering ratio in this energy range. It was found that, in order to be consistent with the experimental results, an accurate description at low Z must include nonlocal exchange, electron correlation, and dynamic effects. The second experiment concerns the ratio of helium double-to-single ionization for Compton scattering in the 8-28 keV energy range where published experimental and theoretical results so far fail to give a consistent picture. The progress of the experiment and the data analysis is reported

Small angle X-ray scattering from hydrating tricalcium silicate

International Nuclear Information System (INIS)

Vollet, D.

1983-01-01

The small-angle X-ray scattering technique was used to study the structural evolution of hydrated tricalcium silicate at room temperature. The changes in specific area of the associated porosity and the evolution of density fluctuations in the solid hydrated phase were deduced from the scattering data. A correlation of these variations with the hydration mechanism is tried. (Author) [pt

X rays and condensed matter

International Nuclear Information System (INIS)

Daillant, J.

1997-01-01

After a historical review of the discovery and study of X rays, the various interaction processes between X rays and matter are described: Thomson scattering, Compton scattering, X-photon absorption through photoelectric effect, and magnetic scattering. X ray sources such as the European Synchrotron Radiation Facility (ESRF) are described. The various X-ray applications are presented: imagery such as X tomography, X microscopy, phase contrast; X-ray photoelectron spectroscopy and X-ray absorption spectroscopy; X-ray scattering and diffraction techniques

ORNL 10-m small-angle X-ray scattering camera

International Nuclear Information System (INIS)

Hendricks, R.W.

1979-12-01

A new small-angle x-ray scattering camera utilizing a rotating anode x-ray source, crystal monochromatization of the incident beam, pinhole collimation, and a two-dimensional position-sensitive proportional counter was developed. The sample, and the resolution element of the detector are each approximately 1 x 1 mm 2 , the camera was designed so that the focal spot-to-sample and sample-to-detector distances may each be varied in 0.5-m increments up to 5 m to provide a system resolution in the range 0.5 to 4.0 mrad. A large, general-purpose specimen chamber has been provided into which a wide variety of special-purpose specimen holders can be mounted. The detector has an active area of 200 x 200 mm and has up to 200 x 200 resolution elements. The data are recorded in the memory of a minicomputer by a high-speed interface which uses a microprocessor to map the position of an incident photon into an absolute minicomputer memory address. The data recorded in the computer memory can be processed on-line by a variety of programs designed to enhance the user's interaction with the experiment. At the highest angular resolution (0.4 mrad), the flux incident on the specimen is 1.0 x 10 6 photons/s with the x-ray source operating at 45 kV and 100 mA. SAX and its associated programs OVF and MOT are high-priority, pre-queued, nonresident foreground tasks which run under the ModComp II MAX III operating system to provide complete user control of the ORNL 10-m small-angle x-ray scattering camera

Status of Kharkov X-ray Generator based on Compton Scattering NESTOR

NARCIS (Netherlands)

Zelinsky, A.; Androsov, V.P.; Bulyak, E.V.; Drebot, I.; Gladkikh, P.I.; Grevtsev, V.; Botman, J.I.M.; Ivashchenko, V.; Karnaukhov, I.M.; Lapshin, V.I.; Markov, V.; Mocheshnikov, N.; Mytsykov, A.; Peev, F.A.; Rezaev, A.; Shcherbakov, A.; Skomorkohov, V.; Skyrda, V.; Telegin, Y.; Trotsenko, V.; Tatchyn, R.; Lebedev, B.; Agafonov, A.V.

2004-01-01

Nowadays the sources of the X-rays based on a storage ring with low beam energy and Compton scattering of intense laser beam are under development in several laboratories. In the paper the state-of-art in development and construction of cooperative project of a Kharkov advanced X-ray source NESTOR

Revealing inner shell dynamics with inelastic X-ray scattering

International Nuclear Information System (INIS)

Franck, C.

1990-01-01

One of the many opportunities provided by the Advanced Photon Source (APS) is to extend the study of intra-atomic dynamics. As a means of testing dynamic response, inelastic x-ray scattering is particularly promising since it allows us to independently vary the period of the exciting field in both space and time. As an example of this type of work, the author presents experiments performed at the Cornell High Energy Synchrotron Source (CHESS) laboratory, a prototype for the APS. This was inner shell inelastic scattering with a twist: in order to explore a new distance scale an x-ray fluorescence trigger was employed. Aside for the atomic insight gained, the experiment taught them the importance of the time structure of the synchrotron beam for coincidence experiments which are dominated by accidental events

Real-time, ray casting-based scatter dose estimation for c-arm x-ray system.

Science.gov (United States)

Alnewaini, Zaid; Langer, Eric; Schaber, Philipp; David, Matthias; Kretz, Dominik; Steil, Volker; Hesser, Jürgen

2017-03-01

Dosimetric control of staff exposure during interventional procedures under fluoroscopy is of high relevance. In this paper, a novel ray casting approximation of radiation transport is presented and the potential and limitation vs. a full Monte Carlo transport and dose measurements are discussed. The x-ray source of a Siemens Axiom Artix C-arm is modeled by a virtual source model using single Gaussian-shaped source. A Geant4-based Monte Carlo simulation determines the radiation transport from the source to compute scatter from the patient, the table, the ceiling and the floor. A phase space around these scatterers stores all photon information. Only those photons are traced that hit a surface of phantom that represents medical staff in the treatment room, no indirect scattering is considered; and a complete dose deposition on the surface is calculated. To evaluate the accuracy of the approximation, both experimental measurements using Thermoluminescent dosimeters (TLDs) and a Geant4-based Monte Carlo simulation of dose depositing for different tube angulations of the C-arm from cranial-caudal angle 0° and from LAO (Left Anterior Oblique) 0°-90° are realized. Since the measurements were performed on both sides of the table, using the symmetry of the setup, RAO (Right Anterior Oblique) measurements were not necessary. The Geant4-Monte Carlo simulation agreed within 3% with the measured data, which is within the accuracy of measurement and simulation. The ray casting approximation has been compared to TLD measurements and the achieved percentage difference was -7% for data from tube angulations 45°-90° and -29% from tube angulations 0°-45° on the side of the x-ray source, whereas on the opposite side of the x-ray source, the difference was -83.8% and -75%, respectively. Ray casting approximation for only LAO 90° was compared to a Monte Carlo simulation, where the percentage differences were between 0.5-3% on the side of the x-ray source where the highest dose

Quantitative characterization of fatty liver disease using x-ray scattering

International Nuclear Information System (INIS)

Elsharkawy, Wafaa B.; Elshemey, Wael M.

2013-01-01

Nonalcoholic fatty liver disease (NAFLD) is a dynamic condition in which fat abnormally accumulates within the hepatocytes. It is believed to be a marker of risk of later chronic liver diseases, such as liver cirrhosis and carcinoma. The fat content in liver biopsies determines its validity for liver transplantation. Transplantation of livers with severe NAFLD is associated with a high risk of primary non-function. Moreover, NAFLD is recognized as a clinically important feature that influences patient morbidity and mortality after hepatic resection. Unfortunately, there is a lack in a precise, reliable and reproducible method for quantification of NAFLD. This work suggests a method for the quantification of NAFLD. The method is based on the fact that fatty liver tissue would have a characteristic x-ray scattering profile with a relatively intense fat peak at a momentum transfer value of 1.1 nm −1 compared to a soft tissue peak at 1.6 nm −1 . The fat content in normal and fatty liver is plotted against three profile characterization parameters (ratio of peak intensities, ratio of area under peaks and ratio of area under fat peak to total profile area) for measured and Monte Carlo simulated x-ray scattering profiles. Results show a high linear dependence (R 2 >0.9) of the characterization parameters on the liver fat content with a reported high correlation coefficient (>0.9) between measured and simulated data. These results indicate that the current method probably offers reliable quantification of fatty liver disease. - Highlights: • A method for the quantification of NAFLD is suggested. • Fatty liver tissue has characteristic x-ray scattering profile. • Profile characterization parameters show differences between normal and fatty liver. • Monte Carlo simulated x-ray scattering profiles are compared to measured

Inelastic X-ray Scattering Beamline Collaborative Development Team Final Report

International Nuclear Information System (INIS)

Burns, Clement

2008-01-01

This is the final report for the project to create a beam line for inelastic x-ray scattering at the Advanced Photon Source. The facility is complete and operating well, with spectrometers for both high resolution and medium resolution measurements. With the advent of third generation synchrotron sources, inelastic x-ray scattering (IXS) has become a valuable technique to probe the electronic and vibrational states of a wide variety of systems of interest in physics, chemistry, and biology. IXS is a weak probe, and experimental setups are complex and require well-optimized spectrometers which need a dedicated beamline to function efficiently. This project was the result of a proposal to provide a world-class, user friendly beamline for IXS at the Advanced Photon Source. The IXS Collaborative Development Team (IXS-CDT) was formed from groups at the national laboratories and a number of different universities. The beamline was designed from the front end to the experimental stations. Two different experimental stations were provided, one for medium resolution inelastic x-ray scattering (MERIX) and a spectrometer for high resolution inelastic x-ray scattering (HERIX). Funding for this project came from several sources as well as the DOE. The beamline is complete with both spectrometers operating well. The facility is now open to the general user community and there has been a tremendous demand to take advantage of the beamline's capabilities. A large number of different experiments have already been carried out on the beamline. A detailed description of the beamline has been given in the final design report (FDR) for the beamline from which much of the material in this report came. The first part of this report contains a general overview of the project with more technical details given later.

Introducing a standard method for experimental determination of the solvent response in laser pump, x-ray probe time-resolved wide-angle x-ray scattering experiments on systems in solution

DEFF Research Database (Denmark)

Kjær, Kasper Skov; Brandt van Driel, Tim; Kehres, Jan

2013-01-01

In time-resolved laser pump, X-ray probe wide-angle X-ray scattering experiments on systems in solution the structural response of the system is accompanied by a solvent response. The solvent response is caused by reorganization of the bulk solvent following the laser pump event, and in order...... response-the solvent term-experimentally when applying laser pump, X-ray probe time-resolved wide-angle X-ray scattering. The solvent term describes difference scattering arising from the structural response of the solvent to changes in the hydrodynamic parameters: pressure, temperature and density. We...... is demonstrated to exhibit first order behaviour with respect to the amount of energy deposited in the solution. We introduce a standardized method for recording solvent responses in laser pump, X-ray probe time-resolved X-ray wide-angle scattering experiments by using dye mediated solvent heating. Furthermore...

X-ray magnetic scattering in SDW Cr - ab initio study

International Nuclear Information System (INIS)

Takahashi, M.; Igarashi, J.-I.; Hirai, K.

2004-01-01

Full text: Resonant x-ray scattering at the K-edge of transition metal atom has attracted much attention as a powerful tool for obtaining information on magnetic or orbital properties of 3d electrons. Recently Mannix et al. performed the x-ray magnetic scattering experiment in SDW Chromium and observed the finite scattering intensity with resonant enhancement at Cr K-edge on the SDW magnetic spot (0, 0, 1 ±δ). Applying ab-initio band structure calculation based on the local spin density approximation, we analyze the scattering spectra and elucidate the mechanism of the resonant enhancement in connection with the electronic structure. We assumed the bcc structure with the lattice constant a = 5.45a 0 and the SDW wavelength λ SDW = 20a, which are nearly equilibrium value at the spin-flip temperature T SF = 122K. The K-edge x-ray absorption and scattering spectra are calculated using Fermi's golden rule. We evaluate the non-resonant scattering amplitude within the spherical and dipolar approximations for spin and orbital moment contributions, respectively. The calculated absorption spectra are in good agreement with the experiment. This may assure the validity of the calculation. We obtained finite scattering amplitude with resonant enhancement at the K-edge. The calculated photon energy dependence of the scattering intensity shows good agreement with the experiment. The contribution of the 3d and 4p orbital moments to the non-resonant scattering amplitude is negligible in consequence of the smallness of their values, which are l max d ∼ 0.006ℎ and l max p ∼ 0.00007ℎ. On the other hand, although the 3d and 4p orbital moments are infinitesimal, they play important role on the resonant enhancement, which occurs through the 1s - 4p dipole transition and reflects the 4p orbital polarization. The 4p orbital polarization is caused by the on-site spin-orbit interaction in 4p orbital itself and the hybridization of the 4p orbital with the 3d orbital at neighboring

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

Energy Technology Data Exchange (ETDEWEB)

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

1989-11-10

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

Possibility of single biomolecule imaging with coherent amplification of weak scattering x-ray photons.

Science.gov (United States)

Shintake, Tsumoru

2008-10-01

The number of photons produced by coherent x-ray scattering from a single biomolecule is very small because of its extremely small elastic-scattering cross section and low damage threshold. Even with a high x-ray flux of 3 x 10;{12} photons per 100-nm -diameter spot and an ultrashort pulse of 10 fs driven by a future x-ray free electron laser (x-ray FEL), it has been predicted that only a few 100 photons will be produced from the scattering of a single lysozyme molecule. In observations of scattered x rays on a detector, the transfer of energy from wave to matter is accompanied by the quantization of the photon energy. Unfortunately, x rays have a high photon energy of 12 keV at wavelengths of 1A , which is required for atomic resolution imaging. Therefore, the number of photoionization events is small, which limits the resolution of imaging of a single biomolecule. In this paper, I propose a method: instead of directly observing the photons scattered from the sample, we amplify the scattered waves by superimposing an intense coherent reference pump wave on it and record the resulting interference pattern on a planar x-ray detector. Using a nanosized gold particle as a reference pump wave source, we can collect 10;{4}-10;{5} photons in single shot imaging where the signal from a single biomolecule is amplified and recorded as two-dimensional diffraction intensity data. An iterative phase retrieval technique can be used to recover the phase information and reconstruct the image of the single biomolecule and the gold particle at the same time. In order to precisely reconstruct a faint image of the single biomolecule in Angstrom resolution, whose intensity is much lower than that of the bright gold particle, I propose a technique that combines iterative phase retrieval on the reference pump wave and the digital Fourier transform holography on the sample. By using a large number of holography data, the three-dimensional electron density map can be assembled.

On-axis microscopes for the inelastic x-ray scattering beamline at NSLS-II

Energy Technology Data Exchange (ETDEWEB)

Gofron, K. J., E-mail: kgofron@bnl.gov; Cai, Y. Q.; Coburn, D. S.; Antonelli, S.; Suvorov, A. [National Synchrotron Light Source II, Brookhaven National Laboratory, Upton, NY 11973 (United States); Flores, J. [Department of Physics and Astronomy, Stony Brook University, NY 11794 (United States)

2016-07-27

A novel on-axis X-ray microscope with 3 µm resolution, 3x magnification, and a working distance of 600 mm for in-situ sample alignment and X-ray beam visualization for the Inelastic X-ray Scattering (IXS) beamline at NSLS-II is presented. The microscope uses reflective optics, which minimizes dispersion, and allows imaging from Ultraviolet (UV) to Infrared (IR) with specifically chosen objective components (coatings, etc.). Additionally, a portable high resolution X-ray microscope for KB mirror alignment and X-ray beam characterization was developed.

A preliminary study of breast cancer diagnosis using laboratory based small angle x-ray scattering

Science.gov (United States)

Round, A. R.; Wilkinson, S. J.; Hall, C. J.; Rogers, K. D.; Glatter, O.; Wess, T.; Ellis, I. O.

2005-09-01

Breast tissue collected from tumour samples and normal tissue from bi-lateral mastectomy procedures were examined using small angle x-ray scattering. Previous work has indicated that breast tissue disease diagnosis could be performed using small angle x-ray scattering (SAXS) from a synchrotron radiation source. The technique would be more useful to health services if it could be made to work using a conventional x-ray source. Consistent and reliable differences in x-ray scatter distributions were observed between samples from normal and tumour tissue samples using the laboratory based 'SAXSess' system. Albeit from a small number of samples, a sensitivity of 100% was obtained. This result encourages us to pursue the implementation of SAXS as a laboratory based diagnosis technique.

A preliminary study of breast cancer diagnosis using laboratory based small angle x-ray scattering

Energy Technology Data Exchange (ETDEWEB)

Round, A R [Daresbury Laboratories, Warrington, WA4 4AD (United Kingdom); Wilkinson, S J [Daresbury Laboratories, Warrington, WA4 4AD (United Kingdom); Hall, C J [Daresbury Laboratories, Warrington, WA4 4AD (United Kingdom); Rogers, K D [Department of Materials and Medical Sciences, Cranfield University, Swindon, SN6 8LA (United Kingdom); Glatter, O [Department of Chemistry, University of Graz (Austria); Wess, T [School of Optometry and Vision Sciences, Cardiff University, Cardiff CF10 3NB, Wales (United Kingdom); Ellis, I O [Nottingham City Hospital, Nottingham (United Kingdom)

2005-09-07

Breast tissue collected from tumour samples and normal tissue from bi-lateral mastectomy procedures were examined using small angle x-ray scattering. Previous work has indicated that breast tissue disease diagnosis could be performed using small angle x-ray scattering (SAXS) from a synchrotron radiation source. The technique would be more useful to health services if it could be made to work using a conventional x-ray source. Consistent and reliable differences in x-ray scatter distributions were observed between samples from normal and tumour tissue samples using the laboratory based 'SAXSess' system. Albeit from a small number of samples, a sensitivity of 100% was obtained. This result encourages us to pursue the implementation of SAXS as a laboratory based diagnosis technique.

A preliminary study of breast cancer diagnosis using laboratory based small angle x-ray scattering

International Nuclear Information System (INIS)

Round, A R; Wilkinson, S J; Hall, C J; Rogers, K D; Glatter, O; Wess, T; Ellis, I O

2005-01-01

Breast tissue collected from tumour samples and normal tissue from bi-lateral mastectomy procedures were examined using small angle x-ray scattering. Previous work has indicated that breast tissue disease diagnosis could be performed using small angle x-ray scattering (SAXS) from a synchrotron radiation source. The technique would be more useful to health services if it could be made to work using a conventional x-ray source. Consistent and reliable differences in x-ray scatter distributions were observed between samples from normal and tumour tissue samples using the laboratory based 'SAXSess' system. Albeit from a small number of samples, a sensitivity of 100% was obtained. This result encourages us to pursue the implementation of SAXS as a laboratory based diagnosis technique

Femtosecond X-ray scattering in condensed matter

Energy Technology Data Exchange (ETDEWEB)

Korff Schmising, Clemens von

2008-11-24

This thesis investigates the manifold couplings between electronic and structural properties in crystalline Perovskite oxides and a polar molecular crystal. Ultrashort optical excitation changes the electronic structure and the dynamics of the connected reversible lattice rearrangement is imaged in real time by femtosecond X-ray scattering experiments. An epitaxially grown superlattice consisting of alternating nanolayers of metallic and ferromagnetic strontium ruthenate (SRO) and dielectric strontium titanate serves as a model system to study optically generated stress. In the ferromagnetic phase, phonon-mediated and magnetostrictive stress in SRO display similar sub-picosecond dynamics, similar strengths but opposite sign and different excitation spectra. The amplitude of the magnetic component follows the temperature dependent magnetization square, whereas the strength of phononic stress is determined by the amount of deposited energy only. The ultrafast, phonon-mediated stress in SRO compresses ferroelectric nanolayers of lead zirconate titanate in a further superlattice system. This change of tetragonal distortion of the ferroelectric layer reaches up to 2 percent within 1.5 picoseconds and couples to the ferroelectric soft mode, or ion displacement within the unit cell. As a result, the macroscopic polarization is reduced by up to 100 percent with a 500 femtosecond delay that is due to final elongation time of the two anharmonically coupled modes. Femtosecond photoexcitation of organic chromophores in a molecular, polar crystal induces strong changes of the electronic dipole moment via intramolecular charge transfer. Ultrafast changes of transmitted X-ray intensity evidence an angular rotation of molecules around excited dipoles following the 10 picosecond kinetics of the charge transfer reaction. Transient X-ray scattering is governed by solvation, masking changes of the chromophore's molecular structure. (orig.)

Femtosecond X-ray scattering in condensed matter

International Nuclear Information System (INIS)

Korff Schmising, Clemens von

2008-01-01

This thesis investigates the manifold couplings between electronic and structural properties in crystalline Perovskite oxides and a polar molecular crystal. Ultrashort optical excitation changes the electronic structure and the dynamics of the connected reversible lattice rearrangement is imaged in real time by femtosecond X-ray scattering experiments. An epitaxially grown superlattice consisting of alternating nanolayers of metallic and ferromagnetic strontium ruthenate (SRO) and dielectric strontium titanate serves as a model system to study optically generated stress. In the ferromagnetic phase, phonon-mediated and magnetostrictive stress in SRO display similar sub-picosecond dynamics, similar strengths but opposite sign and different excitation spectra. The amplitude of the magnetic component follows the temperature dependent magnetization square, whereas the strength of phononic stress is determined by the amount of deposited energy only. The ultrafast, phonon-mediated stress in SRO compresses ferroelectric nanolayers of lead zirconate titanate in a further superlattice system. This change of tetragonal distortion of the ferroelectric layer reaches up to 2 percent within 1.5 picoseconds and couples to the ferroelectric soft mode, or ion displacement within the unit cell. As a result, the macroscopic polarization is reduced by up to 100 percent with a 500 femtosecond delay that is due to final elongation time of the two anharmonically coupled modes. Femtosecond photoexcitation of organic chromophores in a molecular, polar crystal induces strong changes of the electronic dipole moment via intramolecular charge transfer. Ultrafast changes of transmitted X-ray intensity evidence an angular rotation of molecules around excited dipoles following the 10 picosecond kinetics of the charge transfer reaction. Transient X-ray scattering is governed by solvation, masking changes of the chromophore's molecular structure. (orig.)

Resonant inelastic scattering at intermediate X-ray energies

CERN Document Server

Hague, C F; Journel, L; Gallet, J J; Rogalev, A; Krill, G; Kappler, J P

2000-01-01

We describe resonant inelastic X-ray scattering (RIXS) experiments and magnetic circular dichroism (MCD) in X-ray fluorescence performed in the 3-5 keV range. The examples chosen are X-ray fluorescence MCD of FeRh and RIXS experiments performed at the L/sub 3/ edge of Ce. Fe Rh is antiferromagnetic at room temperature but has a transition to the ferromagnetic state above 400 K. The Rh MCD signal is compared with an augmented spherical wave calculation. The experiment confirms the predicted spin polarization of the Rh 4d valence states. The RIXS measurements on Ce compounds and intermetallics address the problem of mixed valency especially in systems where degeneracy with the Fermi level remains small. Examples are taken from the 2p to (4f5d) /sup +1/ followed by 3d to 2p RIXS for a highly ionic compound CeF /sub 3/ and for almost gamma -like CeCuSi. (38 refs).

Small angle x-ray scattering from proteins in solution

International Nuclear Information System (INIS)

de Souza, C.F.; Torriani, I.L.; Bonafe, C.F.S.; Merrelles, N.C.; Vachette, P.

1989-01-01

In this work the authors report experiments performed with giant respiratory proteins from annelids (erythrocruorins), known to have a molecular weight in the order of four million Daltons. Preliminary x-ray scattering data was obtained using a conventional rotating anode source. High resolution small angle scattering curves were obtained with synchrotron radiation from the DCI storage ring at LURE. Data from solutions with several protein concentrations were analyzed in order to determine low resolution dimensional parameters, using Guinier plots from the smeared scattering curves and the inverse transformation method

Theory of inelastic scattering and absorption of X-rays

CERN Document Server

Veenendaal, Michel van

2015-01-01

This comprehensive, self-contained guide to X-ray spectroscopy will equip you with everything you need to begin extracting the maximum amount of information available from X-ray spectra. Key topics such as the interaction between X-rays and matter, the basic theory of spectroscopy, and selection and sum rules, are introduced from the ground up, providing a solid theoretical grounding. The book also introduces core underlying concepts such as atomic structure, solid-state effects, the fundamentals of tensor algebra and group theory, many-body interactions, scattering theory, and response functions, placing spectroscopy within a broader conceptual framework, and encouraging a deep understanding of this essential theoretical background. Suitable for graduate students, researchers, materials scientists and optical engineers, this is the definitive guide to the theory behind this powerful and widely used technique.

A synchrotron radiation camera and data acquisition system for time resolved x-ray scattering studies

International Nuclear Information System (INIS)

Bordas, J.; Koch, M.H.J.; Clout, P.N.; Dorrington, E.; Boulin, C.; Gabriel, A.

1980-01-01

Until recently, time resolved measurements of x-ray scattering patterns have not been feasible because laboratory x-ray sources were too weak and detectors unavailable. Recent developments in both these fields have changed the situation, and it is now possible to follow changes in x-ray scattering patterns with a time resolution of a few ms. The apparatus used to achieve this is described and some examples from recent biological experiments are given. (author)

New X-ray beam position monitors with submicron resolution utilizing imaging of scattered X-rays at CHESS

International Nuclear Information System (INIS)

Revesz, Peter; Temnykh, Alexander B.; Pauling, Alan K.

2011-01-01

At CHESS' A, F and G wiggler beam lines three new video beam position monitors (VBPMs) have been commissioned. These new VBPMs utilize X-rays scattered from the graphite filter (A and F line) or from a beryllium window (G-line) as the white wiggler beam passes through them. As the X-rays scatter in all directions from the scattering medium, a slit camera creates an image of the beam's footprint on a fluorescent screen. This image is then viewed by a CCD camera and analyzed using a computer program to calculate the intensity centroid, the beam profile and integrated intensity. These data are delivered to the CHESS signal archiving system for storage and display. The new systems employ digital cameras. These cameras are free of the noise inherent to the analog systems with long video signal connections. As a result, the beam position data delivered by the new systems are more reliable and accurate as shown by beam position traces using different beam position monitors on the same beam line.

New X-ray beam position monitors with submicron resolution utilizing imaging of scattered X-rays at CHESS

Energy Technology Data Exchange (ETDEWEB)

Revesz, Peter, E-mail: pr20@cornell.edu [Cornell University, Cornell High Energy Synchrotron Source, Ithaca 14850, NY (United States); Temnykh, Alexander B. [Cornell University, Laboratory for Elem-Particle Physics, Ithaca 14850, NY (United States); Pauling, Alan K. [Cornell University, Cornell High Energy Synchrotron Source, Ithaca 14850, NY (United States)

2011-09-01

At CHESS' A, F and G wiggler beam lines three new video beam position monitors (VBPMs) have been commissioned. These new VBPMs utilize X-rays scattered from the graphite filter (A and F line) or from a beryllium window (G-line) as the white wiggler beam passes through them. As the X-rays scatter in all directions from the scattering medium, a slit camera creates an image of the beam's footprint on a fluorescent screen. This image is then viewed by a CCD camera and analyzed using a computer program to calculate the intensity centroid, the beam profile and integrated intensity. These data are delivered to the CHESS signal archiving system for storage and display. The new systems employ digital cameras. These cameras are free of the noise inherent to the analog systems with long video signal connections. As a result, the beam position data delivered by the new systems are more reliable and accurate as shown by beam position traces using different beam position monitors on the same beam line.

Dichroism in resonant inelastic soft X-ray scattering

International Nuclear Information System (INIS)

Braicovich, L.

2004-01-01

Full text: The dichroism (and in particular the magnetic dichroism) has emerged in the last decade as a key method in the study of electronic states in solids. This has been largely due to the exploitation of the modern sources of Synchrotron Radiation. This approach has been extensively used in X ray Absorption Spectroscopy i.e. in a first order process giving a straightforward access, trough sum rules, to the ground state properties of the sample. On the other hand the studies of dichroism in second order processes as the photon scattering experiments has been up to now relatively limited probably due to experimental difficulties. This is too bad because, at least in principle, the scattering experiments offer unique opportunities typical of second order processes, beyond the possibilities offered by absorption spectroscopy. This requires specific scattering experiments able to give information that cannot be obtained in the absorption mode. A typical example is the circular magnetic dichroism in resonant inelastic scattering in perpendicular geometry i.e. with the light incident perpendicular to the magnetisation. In this case the circular dichroism in absorption is zero by symmetry while the detection of the scattered photons at an angle breaks the left-right symmetry and allows a dichroism to be observed. The aim of the present talk is to review critically the dichroism in resonant X-ray scattering and to show the potential of this approach. In particular it will be shown how to recover, in magnetic samples, the ground state information up to the moments of order four. In this connection original results will be presented including the demonstration of a new experimental approach. The perspectives of the field will be also discussed

Generation of Attosecond X-Ray Pulse through Coherent Relativistic Nonlinear Thomson Scattering

CERN Document Server

Lee, K; Jeong, Y U; Lee, B C; Park, S H

2005-01-01

In contrast to some recent experimental results, which state that the Nonlinear Thomson Scattered (NTS) radiation is incoherent, a coherent condition under which the scattered radiation of an incident laser pulse by a bunch of electrons can be coherently superposed has been investigated. The Coherent Relativistic Nonlinear Thomson Scattered (C-RNTS) radiation makes it possible utilizing the ultra-short pulse nature of NTS radiation with a bunch of electrons, such as plasma or electron beams. A numerical simulation shows that a 25 attosecond X-ray pulse can be generated by irradiating an ultra-intense laser pulse of 4x10(19) W/cm2 on an ultra-thin solid target of 50 nm thickness, which is commercially available. The coherent condition can be easily extended to an electron beam from accelerators. Different from the solid target, much narrower electron beam is required for the generation of an attosecond pulse. Instead, this condition could be applied for the generation of intense Compton scattered X-rays with a...

International workshop on resonant X-ray scattering in electrically-ordered systems

Energy Technology Data Exchange (ETDEWEB)

Collins, S.P.; Pettifer, R.F.; Laundy, D.; Ishida, K.; Kokubun, J.; Giles, C.; Yokaichiya, F.; Song, C.; Lee, K.B.; Ji, S.; Koo, J.; Park, Y.J.; Kim, J.Y.; Park, J.H.; Shin, H.J.; Rhyee, J.S.; Oh, B.H.; Cho, B.K.; Wilkins Stuart, B.; Paixao, J.A.; Caciuffo, R.; Javorsky, P.; Wastin, F.; Rebizant, J.; Detlefs, C.; Bernheoft, N.; Lander, G.H.; Bombardi, A.; Bergevin, F. de; Matteo, S. di; Paolasini, L.; Rodriguez-Carvajal, J.; Carretta, P.; Millet, P.; Caciuffo, R.; Goff, J.P.; Deen, P.P.; Lee, S.; Stunault, A.; Brown, S.; Mannix, D.; McIntyre, G.J.; Ward, R.C.C.; Wells, M.R.; Lorenzo, J.E.; Joly, Y.; Nazarenko, E.; Staub, U.; Srajer, G.; Haskel, D.; Choi, Y.; Lee, D.R.; Lang, J.C.; Meersschaut, J.; Jiang, J.S.; Bader, S.D.; Bouchenoire, L.; Brown, S.D.; Beesley, A.; Herring, A.; Thomas, M.; Thompson, P.; Langridge, S.; Stirling, W.G.; Mirone, A.; Lander, G.; Wilkins, S.; Ward, R.C.C.; Wells, M.R.; Zochowski, S.W.; Garcia, J.; Subias, G.; Blasco, J.; Sanchez, M.C.; Proietti, M.G.; Lovesey, S.W.; Dmitrienko, V.E.; Ovchinnikova, E.N.; Ishida, K.; Kokubun, J.; Kirfel, A.; Collins, S.P.; Laundy, D.; Oreshko, A.P.; Strange, P.; Horne, M.; Arola, E.; Winter, H.; Szotek, Z.; Temmerman, W.M.; Igarashi, J.; Usuda, M.; Takahashi, M.; Matteo, S. di; Bernhoeft, N.; Hill, J.P.; Lang, J.C.; McWhan, D.; Lee, D.R.; Haskel, D.; Srajer, G.; Hatton Peter, D.; Katsumata, K.; Braithwaite, D

2004-07-01

The research field of Resonant X-ray Scattering (RXS) has achieved tremendous progress in the last years. Nowadays RXS is rapidly becoming the crucial technique for investigating the subtleties of microscopic magnetism in systems where the ground state properties reflect a delicate balance between several different correlated processes. The aim of this workshop is to discuss present and future possibilities for RXS investigations of electronic order, including studies of charge, magnetic, and multipolar ordered states. The sessions will cover experimental and theoretical aspects of hard and soft X-ray resonant scattering from single crystals and thin films. This document gathers the summaries of the presentations.

International workshop on resonant X-ray scattering in electrically-ordered systems

International Nuclear Information System (INIS)

Collins, S.P.; Pettifer, R.F.; Laundy, D.; Ishida, K.; Kokubun, J.; Giles, C.; Yokaichiya, F.; Song, C.; Lee, K.B.; Ji, S.; Koo, J.; Park, Y.J.; Kim, J.Y.; Park, J.H.; Shin, H.J.; Rhyee, J.S.; Oh, B.H.; Cho, B.K.; Wilkins Stuart, B.; Paixao, J.A.; Caciuffo, R.; Javorsky, P.; Wastin, F.; Rebizant, J.; Detlefs, C.; Bernheoft, N.; Lander, G.H.; Bombardi, A.; Bergevin, F. de; Matteo, S. di; Paolasini, L.; Rodriguez-Carvajal, J.; Carretta, P.; Millet, P.; Caciuffo, R.; Goff, J.P.; Deen, P.P.; Lee, S.; Stunault, A.; Brown, S.; Mannix, D.; McIntyre, G.J.; Ward, R.C.C.; Wells, M.R.; Lorenzo, J.E.; Joly, Y.; Nazarenko, E.; Staub, U.; Srajer, G.; Haskel, D.; Choi, Y.; Lee, D.R.; Lang, J.C.; Meersschaut, J.; Jiang, J.S.; Bader, S.D.; Bouchenoire, L.; Brown, S.D.; Beesley, A.; Herring, A.; Thomas, M.; Thompson, P.; Langridge, S.; Stirling, W.G.; Mirone, A.; Lander, G.; Wilkins, S.; Ward, R.C.C.; Wells, M.R.; Zochowski, S.W.; Garcia, J.; Subias, G.; Blasco, J.; Sanchez, M.C.; Proietti, M.G.; Lovesey, S.W.; Dmitrienko, V.E.; Ovchinnikova, E.N.; Ishida, K.; Kokubun, J.; Kirfel, A.; Collins, S.P.; Laundy, D.; Oreshko, A.P.; Strange, P.; Horne, M.; Arola, E.; Winter, H.; Szotek, Z.; Temmerman, W.M.; Igarashi, J.; Usuda, M.; Takahashi, M.; Matteo, S. di; Bernhoeft, N.; Hill, J.P.; Lang, J.C.; McWhan, D.; Lee, D.R.; Haskel, D.; Srajer, G.; Hatton Peter, D.; Katsumata, K.; Braithwaite, D.

2004-01-01

The research field of Resonant X-ray Scattering (RXS) has achieved tremendous progress in the last years. Nowadays RXS is rapidly becoming the crucial technique for investigating the subtleties of microscopic magnetism in systems where the ground state properties reflect a delicate balance between several different correlated processes. The aim of this workshop is to discuss present and future possibilities for RXS investigations of electronic order, including studies of charge, magnetic, and multipolar ordered states. The sessions will cover experimental and theoretical aspects of hard and soft X-ray resonant scattering from single crystals and thin films. This document gathers the summaries of the presentations

Thin film growth studies using time-resolved x-ray scattering

Science.gov (United States)

Kowarik, Stefan

2017-02-01

Thin-film growth is important for novel functional materials and new generations of devices. The non-equilibrium growth physics involved is very challenging, because the energy landscape for atomic scale processes is determined by many parameters, such as the diffusion and Ehrlich-Schwoebel barriers. We review the in situ real-time techniques of x-ray diffraction (XRD), x-ray growth oscillations and diffuse x-ray scattering (GISAXS) for the determination of structure and morphology on length scales from Å to µm. We give examples of time resolved growth experiments mainly from molecular thin film growth, but also highlight growth of inorganic materials using molecular beam epitaxy (MBE) and electrochemical deposition from liquids. We discuss how scaling parameters of rate equation models and fundamental energy barriers in kinetic Monte Carlo methods can be determined from fits of the real-time x-ray data.

Observations of non-collective x-ray scattering in warm dense carbon plasma

International Nuclear Information System (INIS)

Bao Lihua; Zhang Jiyan; Zhao Yang; Ding Yongkun; Zhang Xiaoding

2012-01-01

An experiment for observing the spectrally resolved non-collective x-ray scattering in warm dense carbon plasma is presented in this paper. The experiment used Ta M-band x-rays to heat a foamed carbon cylinder sample isochorically and measured the scattering spectrum with a HOPG crystal spectrometer. The spectrum was compared with the calculation results using a Born-Mermin-approximation model. The best fitting was found at an electron temperature of T e =34 eV and an electron density of n e =1.6×10 23 cm −3 .

Density Determination of Metallic Melts from Diffuse X-Ray Scattering

Science.gov (United States)

Brauser, N.; Davis, A.; Greenberg, E.; Prakapenka, V. B.; Campbell, A.

2017-12-01

Liquids comprise several important structural components of the deep Earth, for example, the present outer core and a hypothesized magma ocean early in Earth history. However, the physical properties of the constituent materials of these structures at high pressures and temperatures are less well constrained than their crystalline counterparts. Determination of the physical properties of these liquids can inform geophysical models of the composition and structure of the Earth, but methods for studying the physical properties of liquids at high pressure and temperatures are underdeveloped. One proposed method for direct determination of density of a melt requires analysis of the diffuse scattered X-ray signal of the liquid. Among the challenges to applying this technique to high-pressure melts within a laser heated diamond anvil cell are the low signal-to-noise ratio and overlapping diffraction peaks from the crystalline components of the sample assembly interfering with the diffuse scattering from the liquid. Recent advances in instrumentation at synchrotron X-ray sources have made this method more accessible for determination of density of melted material. In this work we present the technique and report the densities of three high-pressure melts of the FCC metals iron, nickel, and gold derived from diffuse scattered X-ray spectra collected from in situ laser-heated diamond anvil cell synchrotron experiments. The results are compared to densities derived from shock wave experiments.

Small angle X-ray scattering from protein in solution

International Nuclear Information System (INIS)

Souza, C.F. de; Torriani, I.L.

1988-01-01

In this work we report experiments performed with giant respiratory proteins from annelids. X-ray scattering data were obtained both by the use of conventional rotating anod source and synchotron radiation. Data from solutions with several protein concentrations were analyzed. (A.C.A.S.) [pt

Diffuse X-Ray Scattering from Several Platinum Chain Compounds

DEFF Research Database (Denmark)

Braude, A.; Lindegaard-Andersen, Asger; Carneiro, K.

1980-01-01

Values of the Fermi wavevector for several platinum based one-dimensional conductors were determined from diffuse X-ray scattering measurements. The values were compared with those expected from the chemical compositions. The importance of conclusive values of this parameter is stressed and the c...

X-ray diffraction and NMR data for the study of the location of idebenone and idebenol in model membranes

Directory of Open Access Journals (Sweden)

Victoria Gómez-Murcia

2016-06-01

Full Text Available Here we present some of our data about the interaction of idebenone and idebenol with dipalmitoyl-phosphatidylcholine (DPPC. In particular, we include data of small angle X-ray diffraction (SAXD and wide angle X-ray diffraction experiments, obtention of electronic profiles of the membranes, 2H-NMR and 31P-NMR, as part of the research article: “Both idebenone and idebenol are localized near the lipid-water interface of the membrane and increase its fluidity” (Gomez-Murcia et al., 2016 [1]. These data were obtained from model membranes that included different proportions of idebenone and idebenol, at temperatures both above and below of the gel to fluid phase. The X-ray experiments were carried out by using a modified Kratky compact camera (MBraun-Graz-Optical Systems, Graz Austria, incorporating two coupled linear position sensitive detectors. The NMR data were collected from a a Bruker Avance 600 instrument.

A filter based analyzer for studies of X-ray Raman scattering

CERN Document Server

Seidler, G T

2001-01-01

Non-resonant X-ray Raman scattering (XRS) with hard X-rays holds the potential for measuring local structure and local electronic properties around low-Z atoms in environments where traditional soft X-ray techniques are inapplicable. However, the small cross-section for XRS requires that experiments must simultaneously achieve high detection efficiency, large collection solid angles, and good energy resolution. We report here that a simple X-ray analyzer consisting of an absorber and a point-focusing spatial filter can be used to study some X-ray Raman near-edge features. This apparatus has greater than 10% detection efficiency, has an energy resolution of 8 eV, and can be readily extended to collection angles of more than 1 sr. We present preliminary measurements of the XRS from the nitrogen 1 s shell in pyrolitic boron nitride.

Creation of X-Ray Transparency of Matter by Stimulated Elastic Forward Scattering.

Science.gov (United States)

Stöhr, J; Scherz, A

2015-09-04

X-ray absorption by matter has long been described by the famous Beer-Lambert law. Here, we show how this fundamental law needs to be modified for high-intensity coherent x-ray pulses, now available at x-ray free electron lasers, due to the onset of stimulated elastic forward scattering. We present an analytical expression for the modified polarization-dependent Beer-Lambert law for the case of resonant core-to-valence electronic transitions and incident transform limited x-ray pulses. Upon transmission through a solid, the resonant absorption and dichroic contrasts are found to vanish with increasing x-ray intensity, with the stimulation threshold lowered by orders of magnitude through a resonant superradiantlike effect. Our results have broad implications for the study of matter with x-ray lasers.

A customizable software for fast reduction and analysis of large X-ray scattering data sets: applications of the new DPDAK package to small-angle X-ray scattering and grazing-incidence small-angle X-ray scattering.

Science.gov (United States)

Benecke, Gunthard; Wagermaier, Wolfgang; Li, Chenghao; Schwartzkopf, Matthias; Flucke, Gero; Hoerth, Rebecca; Zizak, Ivo; Burghammer, Manfred; Metwalli, Ezzeldin; Müller-Buschbaum, Peter; Trebbin, Martin; Förster, Stephan; Paris, Oskar; Roth, Stephan V; Fratzl, Peter

2014-10-01

X-ray scattering experiments at synchrotron sources are characterized by large and constantly increasing amounts of data. The great number of files generated during a synchrotron experiment is often a limiting factor in the analysis of the data, since appropriate software is rarely available to perform fast and tailored data processing. Furthermore, it is often necessary to perform online data reduction and analysis during the experiment in order to interactively optimize experimental design. This article presents an open-source software package developed to process large amounts of data from synchrotron scattering experiments. These data reduction processes involve calibration and correction of raw data, one- or two-dimensional integration, as well as fitting and further analysis of the data, including the extraction of certain parameters. The software, DPDAK (directly programmable data analysis kit), is based on a plug-in structure and allows individual extension in accordance with the requirements of the user. The article demonstrates the use of DPDAK for on- and offline analysis of scanning small-angle X-ray scattering (SAXS) data on biological samples and microfluidic systems, as well as for a comprehensive analysis of grazing-incidence SAXS data. In addition to a comparison with existing software packages, the structure of DPDAK and the possibilities and limitations are discussed.

Characterizing the behavior of scattered radiation in multi-energy x-ray imaging

Energy Technology Data Exchange (ETDEWEB)

Sossin, Artur, E-mail: artur.sossin@gmail.com [CEA-LETI MINATEC Grenoble, F-38054 Grenoble (France); Rebuffel, V.; Tabary, J. [CEA-LETI MINATEC Grenoble, F-38054 Grenoble (France); Létang, J.M.; Freud, N. [Univ Lyon, INSA-Lyon, Université Lyon 1, UJM-Saint Etienne, CNRS, Inserm, Centre Léon Bérard, CREATIS UMR 5220 U1206, F-69373 Lyon (France); Verger, L. [CEA-LETI MINATEC Grenoble, F-38054 Grenoble (France)

2017-04-01

Scattered radiation results in various undesirable effects in medical diagnostics, non-destructive testing (NDT) and security x-ray imaging. Despite numerous studies characterizing this phenomenon and its effects, the knowledge of its behavior in the energy domain remains limited. The present study aims at summarizing some key insights on scattered radiation originating from the inspected object. In addition, various simulations and experiments with limited collimation on both simplified and realistic phantoms were conducted in order to study scatter behavior in multi-energy x-ray imaging. Results showed that the spectrum shape of the scatter component can be considered preserved in the first approximation across the image plane for various acquisition geometries and phantoms. The variations exhibited by the scatter spectrum were below 10% for most examined cases. Furthermore, the corresponding spectrum shape proved to be also relatively invariant for different experimental angular projections of one of the examined phantoms. The observed property of scattered radiation can potentially lead to the decoupling of spatial and energy scatter components, which can in turn enable speed ups in scatter simulations and reduce the complexity of scatter correction.

Computational time-resolved and resonant x-ray scattering of strongly correlated materials

Energy Technology Data Exchange (ETDEWEB)

Bansil, Arun [Northeastern Univ., Boston, MA (United States)

2016-11-09

Basic-Energy Sciences of the Department of Energy (BES/DOE) has made large investments in x-ray sources in the U.S. (NSLS-II, LCLS, NGLS, ALS, APS) as powerful enabling tools for opening up unprecedented new opportunities for exploring properties of matter at various length and time scales. The coming online of the pulsed photon source, literally allows us to see and follow the dynamics of processes in materials at their natural timescales. There is an urgent need therefore to develop theoretical methodologies and computational models for understanding how x-rays interact with matter and the related spectroscopies of materials. The present project addressed aspects of this grand challenge of x-ray science. In particular, our Collaborative Research Team (CRT) focused on developing viable computational schemes for modeling x-ray scattering and photoemission spectra of strongly correlated materials in the time-domain. The vast arsenal of formal/numerical techniques and approaches encompassed by the members of our CRT were brought to bear through appropriate generalizations and extensions to model the pumped state and the dynamics of this non-equilibrium state, and how it can be probed via x-ray absorption (XAS), emission (XES), resonant and non-resonant x-ray scattering, and photoemission processes. We explored the conceptual connections between the time-domain problems and other second-order spectroscopies, such as resonant inelastic x-ray scattering (RIXS) because RIXS may be effectively thought of as a pump-probe experiment in which the incoming photon acts as the pump, and the fluorescent decay is the probe. Alternatively, when the core-valence interactions are strong, one can view K-edge RIXS for example, as the dynamic response of the material to the transient presence of a strong core-hole potential. Unlike an actual pump-probe experiment, here there is no mechanism for adjusting the time-delay between the pump and the probe. However, the core hole

Strong Three-magnon Scattering in Cuprates by Resonant X-rays

OpenAIRE

Ament, Luuk J. P.; Brink, Jeroen van den

2010-01-01

We show that Resonant Inelastic X-ray scattering (RIXS) is sensitive to three-magnon excitations in cuprates. Even if it requires three electrons to simultaneously flip their spin, the RIXS tri-magnon scattering amplitude is not small. At the Cu $L$-edge its intensity is generally larger than the bi-magnon one and at low transferred momentum even larger than the single-magnon intensity. At the copper $M$-edge the situation is yet more extreme: in this case three-magnon scattering is dominatin...

Imaging Molecular Motion: Femtosecond X-Ray Scattering of an Electrocyclic Chemical Reaction

Science.gov (United States)

Minitti, M. P.; Budarz, J. M.; Kirrander, A.; Robinson, J. S.; Ratner, D.; Lane, T. J.; Zhu, D.; Glownia, J. M.; Kozina, M.; Lemke, H. T.; Sikorski, M.; Feng, Y.; Nelson, S.; Saita, K.; Stankus, B.; Northey, T.; Hastings, J. B.; Weber, P. M.

2015-06-01

Structural rearrangements within single molecules occur on ultrafast time scales. Many aspects of molecular dynamics, such as the energy flow through excited states, have been studied using spectroscopic techniques, yet the goal to watch molecules evolve their geometrical structure in real time remains challenging. By mapping nuclear motions using femtosecond x-ray pulses, we have created real-space representations of the evolving dynamics during a well-known chemical reaction and show a series of time-sorted structural snapshots produced by ultrafast time-resolved hard x-ray scattering. A computational analysis optimally matches the series of scattering patterns produced by the x rays to a multitude of potential reaction paths. In so doing, we have made a critical step toward the goal of viewing chemical reactions on femtosecond time scales, opening a new direction in studies of ultrafast chemical reactions in the gas phase.

Simbol-X Mirror Module Thermal Shields: II-Small Angle X-Ray Scattering Measurements

Science.gov (United States)

Barbera, M.; Ayers, T.; Collura, A.; Nasillo, G.; Pareschi, G.; Tagliaferri, G.

2009-05-01

The formation flight configuration of the Simbol-X mission implies that the X-ray mirror module will be open to Space on both ends. In order to reduce the power required to maintain the thermal stability and, therefore, the high angular resolution of the shell optics, a thin foil thermal shield will cover the mirror module. Different options are presently being studied for the foil material of these shields. We report results of an experimental investigation conducted to verify that the scattering of X-rays, by interaction with the thin foil material of the thermal shield, will not significantly affect the performances of the telescope.

Simbol-X Mirror Module Thermal Shields: II-Small Angle X-Ray Scattering Measurements

International Nuclear Information System (INIS)

Barbera, M.; Ayers, T.; Collura, A.; Nasillo, G.; Pareschi, G.; Tagliaferri, G.

2009-01-01

The formation flight configuration of the Simbol-X mission implies that the X-ray mirror module will be open to Space on both ends. In order to reduce the power required to maintain the thermal stability and, therefore, the high angular resolution of the shell optics, a thin foil thermal shield will cover the mirror module. Different options are presently being studied for the foil material of these shields. We report results of an experimental investigation conducted to verify that the scattering of X-rays, by interaction with the thin foil material of the thermal shield, will not significantly affect the performances of the telescope.

Design of a scattering polarimeter for hard X-ray astronomy

International Nuclear Information System (INIS)

Costa, E.; Cinti, M.N.; Feroci, M.; Matt, G.; Rapisarda, M.

1995-01-01

The design of a new hard X-ray Compton scattering polarimeter based on scintillating fibre technology is presented and studied in detail by means of Monte Carlo calculations. Several different configurations and materials have been tested in order to optimise the sensitivity in the medium/high energy X-ray band. A high sensitivity over the energy band 20-200 keV is obtained for a two material configuration. The advantages deriving from employing a new scintillating material, the YAP (YAlO 3 ), are also discussed. (orig.)

Au-coated X-ray Anti-scattering Grid Performance Test by MCNP

Energy Technology Data Exchange (ETDEWEB)

Bae, JunWoo; Yoo, Dong Han; Kim, Hee Reyoung [Ulsan National Institute of Science and Technology, Ulsan (Korea, Republic of)

2014-10-15

It is required to protect individual against the dangers of ionizing radiation from medical exposure. And increasing of resolution for x-ray radiography tools can give radiation protectoral benefits. Because the image device has higher resolution in same energy source, it requires low energy level source and it can reduce individual dose. The anti-scattering grid is sub-device that is attached in front of detector (direction of source). It is square lattice shape generally. It is composed of penetration parts and shielding parts. Penetration part is generally air (the void) and in some studies it uses wood or aluminum. Shielding part is composed of various materials such as lead or copper. In this study, it is focused on the gold as one of X-ray grid materials, where gold is generally known as excellent shielding material and the performance test on the gold coated anti-scattering grid is carried out by MCNP simulation. X-ray grid was simulated by using MCNP code and its performance was investigated. It was understood that glass based and Au-coated grid could lessen the scattered photons more where the reduction was about two third. In further study, geometry optimization or material selection will be conducted by MCNP simulation for giving benefits to design proper grid for various instruments.

Difference in x-ray scattering between metallic and non-metallic liquids due to conduction electrons

International Nuclear Information System (INIS)

Chihara, Junzo

1987-01-01

X-ray scattered intensity from a liquid metal as an electron-ion mixture is described using the structure factors, which are exactly expressed in terms of the static and dynamic direct correlation functions. This intensity for a metal is shown to differ from the usual scattered intensity from a non-metal in two points: the atomic form factor and the incoherent (Compton) scattering factor. It is shown that the valence electron form factor, which constitutes the atomic form factor in a liquid metal, leads to a determination of the electron-electron and electron-ion structure factors by combining the ionic structure factor. It is also shown that a part of the electron structure factor, which appears as the incoherent x-ray scattering, is usually approximated as the electron structure factor of the jellium model in the case of a simple metal. As a by-product, the x-ray scattered intensity from a crystalline metal and the inelastic scattering from a liquid metal are given by taking account of the presence of conduction electrons. In this way, we clarify some confusion which appeared in the proposal by Egelstaff et al for extracting the electron-electron correlation function in a metal from x-ray and neutron scattering experiments. A procedure to extract the electron-electron and electron-ion structure factors in a liquid metal is proposed on the basis of formula for scattered intensity derived here. (author)

X-Ray Scattering Applications Using Pulsed X-Ray Sources

Energy Technology Data Exchange (ETDEWEB)

Larson, B.C.

1999-05-23

Pulsed x-ray sources have been used in transient structural phenomena investigations for over fifty years; however, until the advent of synchrotrons sources and the development of table-top picosecond lasers, general access to ligh temporal resolution x-ray diffraction was relatively limited. Advances in diffraction techniques, sample excitation schemes, and detector systems, in addition to IncEased access to pulsed sources, have ld tO what is now a diverse and growing array of pulsed-source measurement applications. A survey of time-resolved investigations using pulsed x-ray sources is presented and research opportunities using both present and planned pulsed x-ray sources are discussed.

Structural investigation of bistrifluron using x-ray crystallography, NMR spectroscopy, and molecular modeling

CERN Document Server

Moon, J K; Rhee, S K; Kim, G B; Yun, H S; Chung, B J; Lee, S S; Lim, Y H

2002-01-01

A new insecticide, bistrifluron acts as an inhibitor of insect development and interferes with the cuticle formation of insects. Since it shows low acute oral and dermal toxicities, it can be one of potent insecticides. Based on X-ray crystallography, NMR spectroscopy and molecular modeling, the structural studies of bistrifluron have been carried out.

X-ray Thomson Scattering from Spherically Imploded ICF Ablators

Science.gov (United States)

Kritcher, Andrea; Doeppner, Tilo; Landen, Otto; Glenzer, Siegfried

2010-11-01

Time-resolved X-ray Thomson scattering measurements from spherically imploded inertial fusion capsules-type targets have been obtained for the first time at the Omega OMEGA laser facility to characterize the in-flight properties of ICF ablators. In these experiments, the non-collective, or microscopic particle behavior, of imploding CH and Be shells, was probed using a 9 keV Zn He-alpha x-ray source at scattering angles of 113^o and 135^o. for two drive pulse shapes.As an example, the analysis of In-flight scattering measurements from one set of directly-driven compressed 8600 μm-diameter, 40-μm thick Be shells taken (4.2 ns after the start of the compression beamswhen compressed a factor of 4.83x) yielded electron densities of ˜ 1.2±0.23x10^24cm-3, temperatures of ˜13±32 eV, and an ionization state of Be(+2), with uncertainties in the temperature and density of about 40% and 20%. These conditions resulting in an inferred adiabat (ratio of plasma pressure to Fermi degenerate pressure) of 1.797 +0.3/-.5 with an error of about 30%. The high signal-to-noise and high signal-to-background ratio of data obtained in these experiments provides a platform for studying the adiabat of other indirect-drive ICF ablators such as CH and High Density Carbon (HDC) ablators and demonstrates the viability of using this diagnostic to study the in-flight properties adiabat of implosion targets at the National Ignition Facility (NIF).

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

International Nuclear Information System (INIS)

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

2005-01-01

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

X-ray scattering in giant magneto-resistive multilayers

International Nuclear Information System (INIS)

Fulthorpe, B.D.

1999-01-01

The scattering mechanisms responsible for Giant Magneto-Resistance (GMR) in magnetic multilayers are believed to be related to many aspects of the multilayer structure. X-ray scattering techniques provide a powerful method with which to study the bulk and interface morphology in these systems, and are therefore crucial in developing an understanding of the dominant factors influencing the magnitude of the GMR. Reflectivity measurements performed on a series of Co/Cu multilayers, sputter deposited onto etched silicon, reveal no variation in the interface roughness with etching voltage, the thickness of the individual layers also remaining constant. The observed decrease in the GMR cannot, therefore, be attributed to variations in spacer thickness or interfacial spin-independent scattering. Electron and X-ray Diffraction measurements suggest the reduction in GMR is due to a loss of antiferromagnetic coupling associated with a transformation of the texture from a randomly oriented to well oriented (111) polycrystalline texture, and subsequent reduction in the volume fraction of (100) oriented grains. Interfaces within Co/Cu are found to propagate with a high degree of conformality with increasing bilayer number, with an out-of-plane correlation length well in excess of 300A. In contrast, the Co/Pt system exhibits a limiting out-of-plane correlation length of the order of 350A arising from a columnar growth mode. X-ray Reflectivity and Diffraction measurements provide' no structural interpretation for the 3-fold enhancement in the rate of increase of the saturation conductivity, as a function of spacer thickness, in Fe/Au (100) compared to Fe/Au (111), or why large oscillations in the GMR occur for the (100) orientation only. Such observations are, however, consistent with the existence of a channelling mechanism in Fe/Au (100). Grazing Incidence Fluorescence data indicates that Nb acts as a surfactant in Fe/Au (111) growth on sapphire. The influence of different

Interplay between structure and magnetism in HoxPr1-x alloys. 2. Resonant x-ray magnetic scattering

DEFF Research Database (Denmark)

Vigliante, A.; Christensen, M.J.; Hill, J.P.

1998-01-01

X-ray-scattering techniques have been used to study the crystal and magnetic structures of HoxPr1-x alloys in the form of thin films. Three distinct crystal structures are found as a function of concentration x, each of which has a characteristic magnetic structure. For x greater than or equal to 0.......6 a hexagonal-close-packed phase is found with the magnetic moments ordered in a basal-plane helix, whereas for 0.4 less than or equal to x... hexagonal-close-packed and remain nonmagnetic down to the lowest temperatures studied. Using x-ray magnetic resonance scattering techniques, we demonstrate that a small, static spin-density wave is induced within the alloy 5d band at both the Pr and Ho sites in both of the magnetically ordered phases...

Methods for reduction of scattered x-ray in measuring MTF with the square chart

International Nuclear Information System (INIS)

Hatagawa, Masakatsu; Yoshida, Rie

1982-01-01

A square wave chart has been used to measure the MTF of a screen-film system. The problem is that the scattered X-ray from the chart may give rise to measurement errors. In this paper, the authors proposed two methods to reduce the scattered X-ray: the first method is the use of a Pb mask and second is to provide for an air gap between the chart and the screen-film system. In these methods, the scattered X-ray from the chart was reduced. MTFs were measured by both of the new methods and the conventional method, and MTF values of the new methods were in good agreement while that of the conventional method was not. It was concluded that these new methods are able to reduce errors in the measurement of MTF. (author)

Multiple scattering theory of X-ray absorption. A review

International Nuclear Information System (INIS)

Fonda, L.

1991-11-01

We review the basic elements of the theory of X-ray absorption using the tools provided by the theory of multiple scattering. A momentum space approach of clear physical insight is used where the final formulas expressing EXAFS and XANES, i.e. the structures appearing in the absorption coefficient above the edge of a deep core level threshold, are given in terms of eigenstates of the photoelectron momentum. A simple graphic representation is given for the multiple scattering function. (author). 38 refs, 4 figs, 1 tab

Evolution of elastic x-ray scattering in laser-shocked warm dense lithium.

Science.gov (United States)

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

2009-12-01

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 degrees using a highly oriented pyrolytic graphite 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 Z[over ] and by extension to the choice of ionization model in the radiation-hydrodynamics simulations used to predict plasma properties within the shocked Li.

Evolution of elastic x-ray scattering in laser-shocked warm dense lithium

International Nuclear Information System (INIS)

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

2009-01-01

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-α photons for x-ray scattering, and the spectrum of scattered photons was recorded at a scattering angle of 120 deg. using a highly oriented pyrolytic graphite 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 Z and by extension to the choice of ionization model in the radiation-hydrodynamics simulations used to predict plasma properties within the shocked Li.

RESONANT MAGNETIC-X-RAY SCATTERING FROM MIXED-VALENCE TMSE

NARCIS (Netherlands)

MCWHAN, DB; ISAACS, ED; CARRA, P; SHAPIRO, SM; THOLE, BT; HOSHINO, S

1993-01-01

The mixed-valent compound TmSe has been studied in its antiferromagnetic state (T x-ray scattering. The (003) magnetic reflection shows two peaks as a function of incident energy corresponding to the L(III) absorption edges of its Tm2+ and Tm2+ configurations. This

Solution Structures of Highly Active Molecular Ir Water-Oxidation Catalysts from Density Functional Theory Combined with High-Energy X-ray Scattering and EXAFS Spectroscopy.

Science.gov (United States)

Yang, Ke R; Matula, Adam J; Kwon, Gihan; Hong, Jiyun; Sheehan, Stafford W; Thomsen, Julianne M; Brudvig, Gary W; Crabtree, Robert H; Tiede, David M; Chen, Lin X; Batista, Victor S

2016-05-04

The solution structures of highly active Ir water-oxidation catalysts are elucidated by combining density functional theory, high-energy X-ray scattering (HEXS), and extended X-ray absorption fine structure (EXAFS) spectroscopy. We find that the catalysts are Ir dimers with mono-μ-O cores and terminal anionic ligands, generated in situ through partial oxidation of a common catalyst precursor. The proposed structures are supported by (1)H and (17)O NMR, EPR, resonance Raman and UV-vis spectra, electrophoresis, etc. Our findings are particularly valuable to understand the mechanism of water oxidation by highly reactive Ir catalysts. Importantly, our DFT-EXAFS-HEXS methodology provides a new in situ technique for characterization of active species in catalytic systems.

An x ray scatter approach for non-destructive chemical analysis of low atomic numbered elements

Science.gov (United States)

Ross, H. Richard

1993-01-01

A non-destructive x-ray scatter (XRS) approach has been developed, along with a rapid atomic scatter algorithm for the detection and analysis of low atomic-numbered elements in solids, powders, and liquids. The present method of energy dispersive x-ray fluorescence spectroscopy (EDXRF) makes the analysis of light elements (i.e., less than sodium; less than 11) extremely difficult. Detection and measurement become progressively worse as atomic numbers become smaller, due to a competing process called 'Auger Emission', which reduces fluorescent intensity, coupled with the high mass absorption coefficients exhibited by low energy x-rays, the detection and determination of low atomic-numbered elements by x-ray spectrometry is limited. However, an indirect approach based on the intensity ratio of Compton and Rayleigh scattered has been used to define light element components in alloys, plastics and other materials. This XRS technique provides qualitative and quantitative information about the overall constituents of a variety of samples.

Low-angle polarized neutron and X-ray scattering from magnetic nanolayers and nanostructures

CERN Document Server

Paul, Amitesh

2017-01-01

This research monograph presents the latest results related to the characterization of low dimensional systems. Low-angle polarized neutron scattering and X-ray scattering at grazing incidence are used as the two main techniques to explore various physical phenomena of these systems. Special focus is put on systems like thin film transition metal and rare-earth layers, oxide heterostructures, hybrid systems, self-assembled nanostructures and self-diffusion.  Readers will gain in-depth knowledge about the usage of specular scattering and off-specular scattering techniques. Investigation of in-plane and out-of-plane structures and magnetism with vector magnetometric information is illustrated comprehensively. The book caters to a wide audience working in the field of nano-dimensional magnetic systems and the neutron and X-ray reflectometry community in particular.

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

Energy Technology Data Exchange (ETDEWEB)

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

2016-02-12

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

Theoretical model of x-ray scattering as a dense matter probe.

Science.gov (United States)

Gregori, G; Glenzer, S H; Rozmus, W; Lee, R W; Landen, O L

2003-02-01

We present analytical expressions for the dynamic structure factor, or form factor S(k,omega), which is the quantity describing the x-ray cross section from a dense plasma or a simple liquid. Our results, based on the random phase approximation for the treatment on the charged particle coupling, can be applied to describe scattering from either weakly coupled classical plasmas or degenerate electron liquids. Our form factor correctly reproduces the Compton energy down-shift and the known Fermi-Dirac electron velocity distribution for S(k,omega) in the case of a cold degenerate plasma. The usual concept of scattering parameter is also reinterpreted for the degenerate case in order to include the effect of the Thomas-Fermi screening. The results shown in this work can be applied to interpreting x-ray scattering in warm dense plasmas occurring in inertial confinement fusion experiments or for the modeling of solid density matter found in the interior of planets.

Magnetic x-ray scattering studies of holmium using synchro- tron radiation

International Nuclear Information System (INIS)

Gibbs, D.; Moncton, D.E.; D'Amico, K.L.; Bohr, J.; Grier, B.H.

1985-01-01

We present the results of magnetic x-ray scattering experiments on the rare-earth metal holmium using synchrotron radiation. Direct high-resolution measurements of the nominally incommensurate magnetic satellite reflections reveal new lock-in behavior which we explain within a simple spin-discommensuration model. As a result of magnetoelastic coupling, the spin-discommensuration array produces additional x-ray diffraction satellites. Their observation further substantiates the model and demonstrates additional advantages of synchrotron radiation for magnetic-structure studies

The 7th Japan-Taiwan joint meeting on neutron and X-ray scattering. Proceedings

International Nuclear Information System (INIS)

2016-03-01

The 7th Japan-Taiwan joint meeting on neutron and X-ray scattering in Kumatori is held bilaterally in Japan and Taiwan. This meeting provides the recent outstanding results in the fields of fundamental polymer and biological sciences and their applications as well. In the fields of the X-ray and/or neutron scattering, the methodological progress expands the research fields and gives us new scientific insights. This meeting invites the researchers developing new methodologies, such as dynamics measurement utilizing nuclear Bragg resonance, subunit-kinetics measurement with deuteration-assisted small-angle neutron scattering and so on. (J.P.N.)

Experimental validation of a multi-energy x-ray adapted scatter separation method

Science.gov (United States)

Sossin, A.; Rebuffel, V.; Tabary, J.; Létang, J. M.; Freud, N.; Verger, L.

2016-12-01

Both in radiography and computed tomography (CT), recently emerged energy-resolved x-ray photon counting detectors enable the identification and quantification of individual materials comprising the inspected object. However, the approaches used for these operations require highly accurate x-ray images. The accuracy of the images is severely compromised by the presence of scattered radiation, which leads to a loss of spatial contrast and, more importantly, a bias in radiographic material imaging and artefacts in CT. The aim of the present study was to experimentally evaluate a recently introduced partial attenuation spectral scatter separation approach (PASSSA) adapted for multi-energy imaging. For this purpose, a prototype x-ray system was used. Several radiographic acquisitions of an anthropomorphic thorax phantom were performed. Reference primary images were obtained via the beam-stop (BS) approach. The attenuation images acquired from PASSSA-corrected data showed a substantial increase in local contrast and internal structure contour visibility when compared to uncorrected images. A substantial reduction of scatter induced bias was also achieved. Quantitatively, the developed method proved to be in relatively good agreement with the BS data. The application of the proposed scatter correction technique lowered the initial normalized root-mean-square error (NRMSE) of 45% between the uncorrected total and the reference primary spectral images by a factor of 9, thus reducing it to around 5%.

X-ray scattering studies of non-equilibrium ordering processes

International Nuclear Information System (INIS)

Nagler, S.E.

1991-01-01

We report on the progress of the project entitled ''X-ray Scattering Studies of Non-Equilibrium Ordering Processes.'' The past year has seen continued progress in the study of kinetic effects in metallic binary alloys and polymers. In addition, work has begun on a low dimensional CDW system: blue bronze. A sample chamber has been constructed to perform small angle neutron scattering measurements on a model quantum system with phase separation: solid He3/He4. Work is continuing on magnetic systems. Planned future experiments include an investigation of crystallization in Rubidium

Rayleigh scatter in kilovoltage x-ray imaging: is the independent atom approximation good enough?

OpenAIRE

Poludniowski, G; Evans, PM; Webb, S

2009-01-01

Monte Carlo simulation is the gold standard method for modelling scattering processes in medical x-ray imaging. General-purpose Monte Carlo codes, however, typically use the independent atom approximation (IAA). This is known to be inaccurate for Rayleigh scattering, for many materials, in the forward direction. This work addresses whether the IAA is sufficient for the typical modelling tasks in medical kilovoltage x-ray imaging. As a means of comparison, we incorporate a more realistic 'inte...

Rayleigh scatter in kilovoltage x-ray imaging: is the independent atom approximation good enough?

Science.gov (United States)

Poludniowski, G.; Evans, P. M.; Webb, S.

2009-11-01

Monte Carlo simulation is the gold standard method for modelling scattering processes in medical x-ray imaging. General-purpose Monte Carlo codes, however, typically use the independent atom approximation (IAA). This is known to be inaccurate for Rayleigh scattering, for many materials, in the forward direction. This work addresses whether the IAA is sufficient for the typical modelling tasks in medical kilovoltage x-ray imaging. As a means of comparison, we incorporate a more realistic 'interference function' model into a custom-written Monte Carlo code. First, we conduct simulations of scatter from isolated voxels of soft tissue, adipose, cortical bone and spongiosa. Then, we simulate scatter profiles from a cylinder of water and from phantoms of a patient's head, thorax and pelvis, constructed from diagnostic-quality CT data sets. Lastly, we reconstruct CT numbers from simulated sets of projection images and investigate the quantitative effects of the approximation. We show that the IAA can produce errors of several per cent of the total scatter, across a projection image, for typical x-ray beams and patients. The errors in reconstructed CT number, however, for the phantoms simulated, were small (typically < 10 HU). The IAA can therefore be considered sufficient for the modelling of scatter correction in CT imaging. Where accurate quantitative estimates of scatter in individual projection images are required, however, the appropriate interference functions should be included.

X-ray diffuse scattering holography of a centrosymmetric sample

Czech Academy of Sciences Publication Activity Database

Kopecký, Miloš; Fábry, Jan; Kub, Jiří; Bussetto, E.; Lausi, A.

2005-01-01

Roč. 87, č. 23 (2005), 231914/1-231914/3 ISSN 0003-6951 R&D Projects: GA AV ČR IAA100100529 Grant - others:EU(XE) HPRI-CT-1999-00033 Institutional research plan: CEZ:AV0Z10100520 Keywords : x-ray holography * diffuse scattering Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 4.127, year: 2005

Modern X-ray spectroscopy 3. X-ray fluorescence holography

International Nuclear Information System (INIS)

Hayashi, Kouichi

2008-01-01

X-ray fluorescence holography (XFH) provides three dimensional atomic images around specified elements. The XFH uses atoms as a wave source or monitor of interference field within a crystal sample, and therefore it can record both intensity and phase of scattered X-rays. Its current performance makes it possible to apply to ultra thin film, impurity and quasicrystal. In this article, I show the theory including solutions for twin image problem, advanced measuring system, data processing for reconstruction of the atomic images and for obtaining accurate atomic positions, applications using resonant X-ray scattering and X-ray excited optical luminescence, and an example of XFH result on the local structure around copper in silicon steal. (author)

Source of X-ray radiation based on back compton scattering

CERN Document Server

Bulyak, E V; Karnaukhov, I M; Kononenko, S G; Lapshin, V G; Mytsykov, A O; Telegin, Yu P; Shcherbakov, A A; Zelinsky, Andrey Yurij

2000-01-01

Applicability was studied and previous estimation was done of power X-ray beams generation by backward Compton scattering of a laser photon beam on a cooled down electron beam. The few MeV electron beam circulating in a compact storage ring can be cooled down by interaction of that beam with powerful laser radiation of micrometer wavelength to achieve normalized emittance of 10 sup - sup 7 m. A tunable X-ray source of photons of energy ranging from few keV up to a hundred keV could result from the interaction of the laser beam with a dense electron beam.

Source of X-ray radiation based on back compton scattering

Energy Technology Data Exchange (ETDEWEB)

Bulyak, E.V.; Gladkikh, P.I.; Karnaukhov, I.M.; Kononenko, S.G.; Lapshin, V.I.; Mytsykov, A.O.; Telegin, Yu.N.; Shcherbakov, A.A. E-mail: shcherbakov@kipt.kharkov.ua; Zelinsky, A.Yu

2000-06-21

Applicability was studied and previous estimation was done of power X-ray beams generation by backward Compton scattering of a laser photon beam on a cooled down electron beam. The few MeV electron beam circulating in a compact storage ring can be cooled down by interaction of that beam with powerful laser radiation of micrometer wavelength to achieve normalized emittance of 10{sup -7} m. A tunable X-ray source of photons of energy ranging from few keV up to a hundred keV could result from the interaction of the laser beam with a dense electron beam.

Source of X-ray radiation based on back compton scattering

International Nuclear Information System (INIS)

Bulyak, E.V.; Gladkikh, P.I.; Karnaukhov, I.M.; Kononenko, S.G.; Lapshin, V.I.; Mytsykov, A.O.; Telegin, Yu.N.; Shcherbakov, A.A.; Zelinsky, A.Yu.

2000-01-01

Applicability was studied and previous estimation was done of power X-ray beams generation by backward Compton scattering of a laser photon beam on a cooled down electron beam. The few MeV electron beam circulating in a compact storage ring can be cooled down by interaction of that beam with powerful laser radiation of micrometer wavelength to achieve normalized emittance of 10 -7 m. A tunable X-ray source of photons of energy ranging from few keV up to a hundred keV could result from the interaction of the laser beam with a dense electron beam

LIGHT SOURCE: A simulation study of Tsinghua Thomson scattering X-ray source

Science.gov (United States)

Tang, Chuan-Xiang; Li, Ren-Kai; Huang, Wen-Hui; Chen, Huai-Bi; Du, Ying-Chao; Du, Qiang; Du, Tai-Bin; He, Xiao-Zhong; Hua, Jian-Fei; Lin, Yu-Zhen; Qian, Hou-Jun; Shi, Jia-Ru; Xiang, Dao; Yan, Li-Xin; Yu, Pei-Cheng

2009-06-01

Thomson scattering X-ray sources are compact and affordable facilities that produce short duration, high brightness X-ray pulses enabling new experimental capacities in ultra-fast science studies, and also medical and industrial applications. Such a facility has been built at the Accelerator Laboratory of Tsinghua University, and upgrade is in progress. In this paper, we present a proposed layout of the upgrade with design parameters by simulation, aiming at high X-ray pulses flux and brightness, and also enabling advanced dynamics studies and applications of the electron beam. Design and construction status of main subsystems are also presented.

Resonant Inelastic X-ray Scattering: From band mapping to inter-orbital excitations

International Nuclear Information System (INIS)

Luning, J.; Hague, C.F.

2008-01-01

Resonant inelastic X-ray scattering (also known as resonant X-ray Raman spectroscopy when only valence and conduction states are involved in the final state excitation) has developed into a major tool for understanding the electronic properties of complex materials. Presently it provides access to electron excitations in the few hundred meV range with element and bulk selectivity. Recent progress in X-ray optics and synchrotron radiation engineering have opened up new perspectives for this powerful technique to improve resolving power and efficiency. We briefly present the basics of the method and illustrate its potential with examples chosen from the literature. (authors)

Interpretation and Utility of the Moments of Small-Angle X-Ray Scattering Distributions.

Science.gov (United States)

Modregger, Peter; Kagias, Matias; Irvine, Sarah C; Brönnimann, Rolf; Jefimovs, Konstantins; Endrizzi, Marco; Olivo, Alessandro

2017-06-30

Small angle x-ray scattering has been proven to be a valuable method for accessing structural information below the spatial resolution limit implied by direct imaging. Here, we theoretically derive the relation that links the subpixel differential phase signal provided by the sample to the moments of scattering distributions accessible by refraction sensitive x-ray imaging techniques. As an important special case we explain the scatter or dark-field contrast in terms of the sample's phase signal. Further, we establish that, for binary phase objects, the nth moment scales with the difference of the refractive index decrement to the power of n. Finally, we experimentally demonstrate the utility of the moments by quantitatively determining the particle sizes of a range of powders with a laboratory-based setup.

Measurements of ionic structure in shock compressed lithium hydride from ultrafast x-ray Thomson scattering.

Science.gov (United States)

Kritcher, A L; Neumayer, P; Brown, C R D; Davis, P; Döppner, T; Falcone, R W; Gericke, D O; Gregori, G; Holst, B; Landen, O L; Lee, H J; Morse, E C; Pelka, A; Redmer, R; Roth, M; Vorberger, J; Wünsch, K; Glenzer, S H

2009-12-11

We present the first ultrafast temporally, spectrally, and angularly resolved x-ray scattering measurements from shock-compressed matter. The experimental spectra yield the absolute elastic and inelastic scattering intensities from the measured density of free electrons. Laser-compressed lithium-hydride samples are well characterized by inelastic Compton and plasmon scattering of a K-alpha x-ray probe providing independent measurements of temperature and density. The data show excellent agreement with the total intensity and structure when using the two-species form factor and accounting for the screening of ion-ion interactions.

X-ray diffuse scattering effects from Coulomb-type defects in multilayered structures

International Nuclear Information System (INIS)

Olikhovskii, S.I.; Molodkin, V.B.; Skakunova, E.S.; Kislovskii, E.N.; Fodchuk, I.M.

2009-01-01

The theoretical X-ray diffraction model starting from Takagi-Taupin equation has been developed for the description of coherent and diffuse components of the rocking curve (RC) measured from the multilayered crystal structure with randomly distributed Coulomb-type defects in all the layers and substrate. The model describes both diffuse scattering (DS) intensity distribution and influence of DS on attenuation and angular redistribution of the coherent X-ray scattering intensity. By analyzing the total measured RC with using the proposed diffraction model, the chemical compositions, strains, and characteristics of dislocation loops in layers and substrate of the multilayered structure with InGaAsN/GaAs single quantum well have been determined. (Abstract Copyright [2009], Wiley Periodicals, Inc.)

Atomic dynamics in fluids studied by inelastic x-ray scattering

International Nuclear Information System (INIS)

Inui, Masanori; Kajihara, Yukio; Matsuda, Kazuhiro; Ishikawa, Daisuke; Tsutsui, Satoshi; Baron, Alfred Q.

2010-01-01

Studies on atomic dynamics in supercritical fluids at high temperature and high pressure have remarkably been advanced by using an inelastic x-ray scattering technique that achieved a meV-energy resolution in the middle of 1990's. In this article, we describe a brief review of the theoretical background on liquid dynamics, our own high-temperature high-pressure technique and recent results of atomic dynamics in supercritical fluids. In particular, we report the results of inelastic x-ray scattering measurements for expanding fluid Hg at high temperature and high pressure, which were conduced at BL35XU/SPring-8. We found that in the metal-nonmetal transition in fluid Hg, the excitation energy of the acoustic mode disperses three times faster than the adiabatic sound velocity obtained by ultrasonic measurements. This phenomenon must be crucial to understand how a metallic state is formed during atomic condensation accurately. Finally we put a future development of this field in perspective. (author)

Tissue Equivalent Phantom Design for Characterization of a Coherent Scatter X-ray Imaging System

Science.gov (United States)

Albanese, Kathryn Elizabeth

Scatter in medical imaging is typically cast off as image-related noise that detracts from meaningful diagnosis. It is therefore typically rejected or removed from medical images. However, it has been found that every material, including cancerous tissue, has a unique X-ray coherent scatter signature that can be used to identify the material or tissue. Such scatter-based tissue-identification provides the advantage of locating and identifying particular materials over conventional anatomical imaging through X-ray radiography. A coded aperture X-ray coherent scatter spectral imaging system has been developed in our group to classify different tissue types based on their unique scatter signatures. Previous experiments using our prototype have demonstrated that the depth-resolved coherent scatter spectral imaging system (CACSSI) can discriminate healthy and cancerous tissue present in the path of a non-destructive x-ray beam. A key to the successful optimization of CACSSI as a clinical imaging method is to obtain anatomically accurate phantoms of the human body. This thesis describes the development and fabrication of 3D printed anatomical scatter phantoms of the breast and lung. The purpose of this work is to accurately model different breast geometries using a tissue equivalent phantom, and to classify these tissues in a coherent x-ray scatter imaging system. Tissue-equivalent anatomical phantoms were designed to assess the capability of the CACSSI system to classify different types of breast tissue (adipose, fibroglandular, malignant). These phantoms were 3D printed based on DICOM data obtained from CT scans of prone breasts. The phantoms were tested through comparison of measured scatter signatures with those of adipose and fibroglandular tissue from literature. Tumors in the phantom were modeled using a variety of biological tissue including actual surgically excised benign and malignant tissue specimens. Lung based phantoms have also been printed for future

Fingerprints of orbital physics in magnetic resonant inelastic X-ray scattering

Science.gov (United States)

Marra, Pasquale

2012-09-01

Orbital degrees of freedom play a major role in the physics of many strongly correlated transition metal compounds. However, they are still very difficult to access experimentally, in particular by neutron scattering. We propose here how to reveal orbital occupancies of the system ground state by magnetic resonant inelastic x-ray scattering (RIXS). This is possible because, unlike in neutron scattering, the intensity of the magnetic excitations in RIXS depends essentially on the symmetry of the orbitals where the spins are in.

Revisiting Bragg's X-ray microscope: Scatter based optical transient grating detection of pulsed ionising radiation

International Nuclear Information System (INIS)

Fullagar, Wilfred K.; Paganin, David M.; Hall, Chris J.

2011-01-01

Transient optical gratings for detecting ultrafast signals are routine for temporally resolved photochemical investigations. Many processes can contribute to the formation of such gratings; we indicate use of optically scattering centres that can be formed with highly variable latencies in different materials and devices using ionising radiation. Coherent light scattered by these centres can form the short-wavelength-to-optical-wavelength, incoherent-to-coherent basis of a Bragg X-ray microscope, with inherent scope for optical phasing. Depending on the dynamics of the medium chosen, the way is open to both ultrafast pulsed and integrating measurements. For experiments employing brief pulses, we discuss high-dynamic-range short-wavelength diffraction measurements with real-time optical reconstructions. Applications to optical real-time X-ray phase-retrieval are considered. -- Research highlights: → It is timely that the concept of Bragg's X-ray microscope be revisited. → Transient gratings can be used for X-ray all-optical information processing. → Applications to optical real-time X-ray phase-retrieval are considered.

Development of a computer model using the EGS4 simulation code to calculate scattered X-rays through some materials

International Nuclear Information System (INIS)

Al-Ghorabie, F.H.H.

2003-01-01

In this paper a computer model based on the use of the well-known Monte Carlo simulation code EGS4 was developed to simulate the scattering of polyenergetic X-ray beams through some materials. These materials are: lucite, polyethylene, polypropylene and aluminium. In particular, the ratio of the scattered to total X-ray fluence (scatter fraction) has been calculated for X-ray beams in the energy region 30-120 keV. In addition scatter fractions have been determined experimentally using a polyenergetic superficial X-ray unit. Comparison of the measured and the calculated results has been performed. The Monte Carlo calculations have also been carried out for water, bakelite and bone to examine the dependence of scatter fraction on the density of the scatterer. Good agreement (estimated statistical error < 5%) was obtained between the measured and the calculated values of the scatter fractions for materials with Z < 20 that were studied in this paper. Copyright (2003) Australasian College of Physical Scientists and Engineers in Medicine

A neutron-X-ray, NMR and calorimetric study of glassy Probucol synthesized using containerless techniques

International Nuclear Information System (INIS)

Weber, J.K.R.; Benmore, C.J.; Tailor, A.N.; Tumber, S.K.; Neuefeind, J.; Cherry, B.; Yarger, J.L.; Mou, Q.; Weber, W.; Byrn, S.R.

2013-01-01

Highlights: • Acoustic levitation was used to make phase-pure glassy forms of pharmaceutical compounds. • Neutrons, X-rays and NMR were used to characterize the glasses. • The glass comprised of slightly distorted molecules packed in a random network. • Potential for new drug synthesis routes is discussed. - Abstract: Acoustic levitation was used to trap 1–3 mm diameter drops of Probucol and other pharmaceutical materials in containerless conditions. Samples were studied in situ using X-ray diffraction and ex situ using neutron diffraction, NMR and DSC techniques. The materials were brought into non-equilibrium states by supersaturating solutions or by supercooling melts. The glass transition and crystallization temperatures of glassy Probucol were 29 ± 1 and 71 ± 1 °C respectively. The glassy form was stable with a shelf life of at least 8 months. A neutron/X-ray difference function of the glass showed that while molecular sub-groups remain rigid, many of the hydrogen correlations observed in the crystal become smeared out in the disordered material. The glass is principally comprised of slightly distorted Form I Probucol molecules with disordered packing rather than large changes in the individual molecular structure. Avoiding surface contact-induced nucleation provided access to highly non-equilibrium phases and enabled synthesis of phase-pure glasses

A neutron-X-ray, NMR and calorimetric study of glassy Probucol synthesized using containerless techniques

Energy Technology Data Exchange (ETDEWEB)

Weber, J.K.R., E-mail: rweber@anl.gov [Materials Development, Inc., Arlington Heights, IL 60004 (United States); Argonne National Laboratory, Argonne, IL 60439 (United States); Benmore, C.J. [Argonne National Laboratory, Argonne, IL 60439 (United States); Department of Physics, Arizona State University, AZ 85287 (United States); Tailor, A.N.; Tumber, S.K. [Materials Development, Inc., Arlington Heights, IL 60004 (United States); Neuefeind, J. [Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States); Cherry, B. [Magnetic Resonance Research Center, Arizona State University, AZ 85287 (United States); Department of Chemistry and Biochemistry, Arizona State University, AZ 85287 (United States); Yarger, J.L. [Department of Physics, Arizona State University, AZ 85287 (United States); Magnetic Resonance Research Center, Arizona State University, AZ 85287 (United States); Department of Chemistry and Biochemistry, Arizona State University, AZ 85287 (United States); Mou, Q. [Magnetic Resonance Research Center, Arizona State University, AZ 85287 (United States); Department of Chemistry and Biochemistry, Arizona State University, AZ 85287 (United States); Weber, W. [Department of Physics, Arizona State University, AZ 85287 (United States); Department of Chemistry and Biochemistry, Arizona State University, AZ 85287 (United States); Byrn, S.R. [Department of Industrial and Physical Pharmacy, Purdue University, IN 47907 (United States)

2013-10-16

Highlights: • Acoustic levitation was used to make phase-pure glassy forms of pharmaceutical compounds. • Neutrons, X-rays and NMR were used to characterize the glasses. • The glass comprised of slightly distorted molecules packed in a random network. • Potential for new drug synthesis routes is discussed. - Abstract: Acoustic levitation was used to trap 1–3 mm diameter drops of Probucol and other pharmaceutical materials in containerless conditions. Samples were studied in situ using X-ray diffraction and ex situ using neutron diffraction, NMR and DSC techniques. The materials were brought into non-equilibrium states by supersaturating solutions or by supercooling melts. The glass transition and crystallization temperatures of glassy Probucol were 29 ± 1 and 71 ± 1 °C respectively. The glassy form was stable with a shelf life of at least 8 months. A neutron/X-ray difference function of the glass showed that while molecular sub-groups remain rigid, many of the hydrogen correlations observed in the crystal become smeared out in the disordered material. The glass is principally comprised of slightly distorted Form I Probucol molecules with disordered packing rather than large changes in the individual molecular structure. Avoiding surface contact-induced nucleation provided access to highly non-equilibrium phases and enabled synthesis of phase-pure glasses.

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

Energy Technology Data Exchange (ETDEWEB)

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 feasibility 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.

A compact X-ray source based on Compton scattering

Energy Technology Data Exchange (ETDEWEB)

Bulyak, E.; Gladkikh, P.; Grigor' ev, Yu.; Guk, I.; Karnaukhov, I.; Khodyachikh, A.; Kononenko, S.; Mocheshnikov, N.; Mytsykov, A.; Shcherbakov, A. E-mail: shcherbakov@kipt.kharkov.ua; Tarasenko, A.; Telegin, Yu.; Zelinsky, A

2001-07-21

The main parameters of Kharkov electron storage ring N-100 with a beam energy range from 70 to 150 MeV are presented. The main results that were obtained in experimental researches are briefly described. The future of the N-100 upgrade to the development of the X-ray generator based on Compton back-scattering are presented. The electron beam energy range will be extended up to 250 MeV and the circumference of the storage ring will be 13.72 m. The lattice, parameters of the electron beam and the Compton back-scattering photons flux are described.

A compact X-ray source based on Compton scattering

International Nuclear Information System (INIS)

Bulyak, E.; Gladkikh, P.; Grigor'ev, Yu.; Guk, I.; Karnaukhov, I.; Khodyachikh, A.; Kononenko, S.; Mocheshnikov, N.; Mytsykov, A.; Shcherbakov, A.; Tarasenko, A.; Telegin, Yu.; Zelinsky, A.

2001-01-01

The main parameters of Kharkov electron storage ring N-100 with a beam energy range from 70 to 150 MeV are presented. The main results that were obtained in experimental researches are briefly described. The future of the N-100 upgrade to the development of the X-ray generator based on Compton back-scattering are presented. The electron beam energy range will be extended up to 250 MeV and the circumference of the storage ring will be 13.72 m. The lattice, parameters of the electron beam and the Compton back-scattering photons flux are described

Using X-ray Thomson Scattering to Characterize Highly Compressed, Near-Degenerate Plasmas at the NIF

Science.gov (United States)

Doeppner, Tilo; Kraus, D.; Neumayer, P.; Bachmann, B.; Divol, L.; Kritcher, A. L.; Landen, O. L.; Fletcher, L.; Glenzer, S. H.; Falcone, R. W.; MacDonald, M. J.; Saunders, A.; Witte, B.; Redmer, R.; Chapman, D.; Baggott, R.; Gericke, D. O.; Yi, S. A.

2017-10-01

We are developing x-ray Thomson scattering for implosion experiments at the National Ignition Facility to characterize plasma conditions in plastic and beryllium capsules near stagnation, reaching more than 20x compression and electron densities of 1025 cm-3, corresponding to a Fermi energy of 170 eV. Using a zinc He- α x-ray source at 9 keV, experiments at a large scattering angle of 120° measure non-collective scattering spectra with high sensitivity to K-shell ionization, and find higher charge states than predicted by widely used ionization models. Reducing the scattering angle to 30° probes the collective scattering regime with sensitivity to collisions and conductivity. We will discuss recent results and future plans. This work was performed under the auspices of the US Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

Coherent scattering X-ray imaging at the Brazilian National Synchrotron Laboratory: Preliminary breast images

Energy Technology Data Exchange (ETDEWEB)

Castro, C.R.F. [Nuclear Instrumentation Laboratory-COPPE/UFRJ, P.O. Box 68509, Rio de Janeiro 21945-970 (Brazil); Barroso, R.C. [Physics Institute-University of Rio de Janeiro State, Rio de Janeiro 20559-900 (Brazil)]. E-mail: cely@uerij.br; Oliveira, L.F. de [Physics Institute-University of Rio de Janeiro State, Rio de Janeiro 20559-900 (Brazil); Lopes, R.T. [Nuclear Instrumentation Laboratory-COPPE/UFRJ, P.O. Box 68509, Rio de Janeiro 21945-970 (Brazil)

2005-08-11

The angular distribution of coherent scatter (low-momentum transfer) carries information about atomic structures, resulting in a pattern, which can be used to reconstruct a series of images. Coherent-scatter computed tomography is a novel imaging method developed to produce cross-sectional images based on the X-ray diffraction properties of an object. A different approach to coherent X-ray imaging is possible by fixing the detector at a given scatter angle {theta}, which produces an interference peak and then, carried out a tomography in the standard way. The cross-sectional images obtained allow determining the spatial dependence of coherent scatter cross-section of selected volume elements of inhomogeneous, extend objects for a single predetermined value of {theta} of interest, leading to a simplification of the data processing and the complexity of the apparatus. This work presents preliminary coherent scattering images carried out at the X-ray Diffraction beamline of the National Synchrotron Light Laboratory in Campinas, Brazil. The specimens were excised human breast tissues fixed in formaline. No frozen procedure was used in order to minimize preferred orientation during sample preparation. About 1mm thick slices cut from each of the fresh samples were mounted in frames without windows and placed on a translator to allow acquisition of scattering spectra. Cylinders containing healthy and cancerous (infiltrating ductal carcinoma) breast tissues were imagined at the characteristic angle for adipose tissue. Transmission and coherent scatter images are compared.

Superhydrophobic surfaces allow probing of exosome self organization using X-ray scattering

KAUST Repository

Accardo, Angelo; Tirinato, Luca; Altamura, Davide; Sibillano, Teresa; Giannini, Cinzia; Riekel, Christian; Di Fabrizio, Enzo M.

2013-01-01

Drops of exosome dispersions from healthy epithelial colon cell line and colorectal cancer cells were dried on a superhydrophobic PMMA substrate. The residues were studied by small- and wide-angle X-ray scattering using both a synchrotron radiation micrometric beam and a high-flux table-top X-ray source. Structural differences between healthy and cancerous cells were detected in the lamellar lattices of the exosome macro-aggregates. © 2013 The Royal Society of Chemistry.

Computer simulation tools for X-ray analysis scattering and diffraction methods

CERN Document Server

Morelhão, Sérgio Luiz

2016-01-01

The main goal of this book is to break down the huge barrier of difficulties faced by beginners from many fields (Engineering, Physics, Chemistry, Biology, Medicine, Material Science, etc.) in using X-rays as an analytical tool in their research. Besides fundamental concepts, MatLab routines are provided, showing how to test and implement the concepts. The major difficult in analyzing materials by X-ray techniques is that it strongly depends on simulation software. This book teaches the users on how to construct a library of routines to simulate scattering and diffraction by almost any kind of samples. It provides to a young student the knowledge that would take more than 20 years to acquire by working on X-rays and relying on the available textbooks. In this book, fundamental concepts in applied X-ray physics are demonstrated through available computer simulation tools. Using MatLab, more than eighty routines are developed for solving the proposed exercises, most of which can be directly used in experimental...

RESONANT X-RAY SCATTERING AS A PROBE OF ORBITAL AND CHARGE ORDERING

International Nuclear Information System (INIS)

NELSON, C.S.; HILL, J.P.; GIBBS, D.

2002-01-01

Resonant x-ray scattering is a powerful experimental technique for probing orbital and charge ordering. It involves tuning the incident photon energy to an absorption edge of the relevant ion and observing scattering at previously 'forbidden' Bragg peaks, and it allows high-resolution, quantitative studies of orbital and charge order--even from small samples. Further, resonant x-ray scattering from orbitally ordered systems exhibits polarization- and azimuthal-dependent properties that provide additional information about the details of the orbital order that is difficult, or impossible, to obtain with any other technique. In the manganites, the sensitivity to charge and orbital ordering is enhanced when the incident photon energy is tuned near the Mn K absorption edge (6.539 keV), which is the lowest energy at which a 1s electron can be excited into an unoccupied state. In this process, the core electron is promoted to an intermediate excited state, which decays with the emission of a photon. The sensitivity to charge ordering is believed to be due to the small difference in K absorption edges of the Mn 3+ and Mn 4+ sites. For orbital ordering, the sensitivity arises from a splitting--or difference in the weight of the density of states [239]--of the orbitals occupied by the excited electron in the intermediate state. In the absence of such a splitting, there is no resonant enhancement of the scattering intensity. In principle, other absorption edges in which the intermediate state is anisotropic could be utilized, but the strong dipole transition to the Mn 4p levels--and their convenient energies for x-ray diffraction--make the K edge well-suited to studies of manganites. The Mn 4p levels are affected by the symmetry of the orbital ordering, which makes the technique sensitive to the orbital degree of freedom. Therefore resonant x-ray scattering can be used to obtain important quantitative information concerning the details of this electronic order. Two

Ultrashort X-ray pulse science

Energy Technology Data Exchange (ETDEWEB)

Chin, Alan Hap [Univ. of California, Berkeley, CA (US). Dept. of Physics; Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

1998-05-01

A variety of phenomena involves atomic motion on the femtosecond time-scale. These phenomena have been studied using ultrashort optical pulses, which indirectly probe atomic positions through changes in optical properties. Because x-rays can more directly probe atomic positions, ultrashort x-ray pulses are better suited for the study of ultrafast structural dynamics. One approach towards generating ultrashort x-ray pulses is by 90° Thomson scattering between terawatt laser pulses and relativistic electrons. Using this technique, the author generated ~ 300 fs, 30 keV (0.4 Å) x-ray pulses. These x-ray pulses are absolutely synchronized with ultrashort laser pulses, allowing femtosecond optical pump/x-ray probe experiments to be performed. Using the right-angle Thomson scattering x-ray source, the author performed time-resolved x-ray diffraction studies of laser-perturbated InSb. These experiments revealed a delayed onset of lattice expansion. This delay is due to the energy relaxation from a dense electron-hole plasma to the lattice. The dense electron-hole plasma first undergoes Auger recombination, which reduces the carrier concentration while maintaining energy content. Longitudinal-optic (LO) phonon emission then couples energy to the lattice. LO phonon decay into acoustic phonons, and acoustic phonon propagation then causes the growth of a thermally expanded layer. Source characterization is instrumental in utilizing ultrashort x-ray pulses in time-resolved x-ray spectroscopies. By measurement of the electron beam diameter at the generation point, the pulse duration of the Thomson scattered x-rays is determined. Analysis of the Thomson scattered x-ray beam properties also provides a novel means of electron bunch characterization. Although the pulse duration is inferred for the Thomson scattering x-ray source, direct measurement is required for other x-ray pulse sources. A method based on the laser-assisted photoelectric effect (LAPE) has been demonstrated as a

Ultrashort X-ray pulse science

International Nuclear Information System (INIS)

Chin, A.H.; Lawrence Berkeley National Lab., CA

1998-01-01

A variety of phenomena involves atomic motion on the femtosecond time-scale. These phenomena have been studied using ultrashort optical pulses, which indirectly probe atomic positions through changes in optical properties. Because x-rays can more directly probe atomic positions, ultrashort x-ray pulses are better suited for the study of ultrafast structural dynamics. One approach towards generating ultrashort x-ray pulses is by 90 o Thomson scattering between terawatt laser pulses and relativistic electrons. Using this technique, the author generated ∼ 300 fs, 30 keV (0.4 (angstrom)) x-ray pulses. These x-ray pulses are absolutely synchronized with ultrashort laser pulses, allowing femtosecond optical pump/x-ray probe experiments to be performed. Using the right-angle Thomson scattering x-ray source, the author performed time-resolved x-ray diffraction studies of laser-perturbated InSb. These experiments revealed a delayed onset of lattice expansion. This delay is due to the energy relaxation from a dense electron-hole plasma to the lattice. The dense electron-hole plasma first undergoes Auger recombination, which reduces the carrier concentration while maintaining energy content. Longitudinal-optic (LO) phonon emission then couples energy to the lattice. LO phonon decay into acoustic phonons, and acoustic phonon propagation then causes the growth of a thermally expanded layer. Source characterization is instrumental in utilizing ultrashort x-ray pulses in time-resolved x-ray spectroscopies. By measurement of the electron beam diameter at the generation point, the pulse duration of the Thomson scattered x-rays is determined. Analysis of the Thomson scattered x-ray beam properties also provides a novel means of electron bunch characterization. Although the pulse duration is inferred for the Thomson scattering x-ray source, direct measurement is required for other x-ray pulse sources. A method based on the laser-assisted photoelectric effect (LAPE) has been

Neutron, x-ray scattering and TEM studies of Ni-Ti multilayers

International Nuclear Information System (INIS)

Keem, J.E.; Wood, J.; Grupido, N.; Hart, K.; Nutt, S.; Reichel, D.G.; Yelon, W.B.

1988-01-01

The authors present an analysis of Ni-Ti multilayer neutron reflectors and supermirrors undertaken to identify the causes of the lower than expected observed scattering power and critical angle enhancement of Ni-Ti supermirrors. Results of these investigations focus attention on cusp formation in the Ni-Ti bilayers as probable cause for the reduced neutron scattering power. Grazing angle x-ray and neutron scattering, wide angle neutron diffraction and analytical cross sectional TEM have been used. The multilayers were produced by magnetron sputtering and ion-beam deposition on float glass substrates and silicon wafers

Small-angle x-ray scattering from the early growth stages of zeolite A

International Nuclear Information System (INIS)

Singh, P.; White, J.

1999-01-01

Full text: The work presented here with the use of SAXS (Small-Angle X-ray Scattering) is in attempt to identify a different paradigm to the organic template induced crystallization of zeolites, in particular zeolite 'A'. The reactions have been followed by small angle X-ray scattering from the time of first mixing of the constituents until the final separation of zeolite A crystals. The processes happening during the growth are expected to follow successive transformation of intermediate metastable phases until the formation of thermodynamically most stable phase and scattering signatures from these developments may be useful for extracting interesting information about the processes in situ. The scattering functions from a synthesis system of zeolite 'A' at the initial and final stage of reaction are presented.The different growth processes of zeolite 'A' from different silicate and aluminium sources are found. The differences are attributed to different rate limiting steps in the syntheses

2,6-Lutidine-isatinecate, a semi-synthetic pyrrolizidine alkaloid: X-ray and n.m.r. studies

International Nuclear Information System (INIS)

Drewes, S.E.; Field, J.S.; Pitchford, A.T.; Van Rooyen, P.H.; Dillen, J.L.M.

1985-01-01

A semi-synthetic pyrrolizidine alkaloid has been prepared from a necic acid and a pyridine base moiety. N.m.r. and X-ray analyses of this compound were carried out in order to establish the relationship between the structure and chemical shift

Deterministic simulation of first-order scattering in virtual X-ray imaging

Energy Technology Data Exchange (ETDEWEB)

Freud, N. E-mail: nicolas.freud@insa-lyon.fr; Duvauchelle, P.; Pistrui-Maximean, S.A.; Letang, J.-M.; Babot, D

2004-07-01

A deterministic algorithm is proposed to compute the contribution of first-order Compton- and Rayleigh-scattered radiation in X-ray imaging. This algorithm has been implemented in a simulation code named virtual X-ray imaging. The physical models chosen to account for photon scattering are the well-known form factor and incoherent scattering function approximations, which are recalled in this paper and whose limits of validity are briefly discussed. The proposed algorithm, based on a voxel discretization of the inspected object, is presented in detail, as well as its results in simple configurations, which are shown to converge when the sampling steps are chosen sufficiently small. Simple criteria for choosing correct sampling steps (voxel and pixel size) are established. The order of magnitude of the computation time necessary to simulate first-order scattering images amounts to hours with a PC architecture and can even be decreased down to minutes, if only a profile is computed (along a linear detector). Finally, the results obtained with the proposed algorithm are compared to the ones given by the Monte Carlo code Geant4 and found to be in excellent accordance, which constitutes a validation of our algorithm. The advantages and drawbacks of the proposed deterministic method versus the Monte Carlo method are briefly discussed.

Fast estimation of first-order scattering in a medical x-ray computed tomography scanner using a ray-tracing technique.

Science.gov (United States)

Liu, Xin

2014-01-01

This study describes a deterministic method for simulating the first-order scattering in a medical computed tomography scanner. The method was developed based on a physics model of x-ray photon interactions with matter and a ray tracing technique. The results from simulated scattering were compared to the ones from an actual scattering measurement. Two phantoms with homogeneous and heterogeneous material distributions were used in the scattering simulation and measurement. It was found that the simulated scatter profile was in agreement with the measurement result, with an average difference of 25% or less. Finally, tomographic images with artifacts caused by scatter were corrected based on the simulated scatter profiles. The image quality improved significantly.

Visualizing a protein quake with time-resolved X-ray scattering at a free-electron laser

DEFF Research Database (Denmark)

Arnlund, David; Johansson, Linda C.; Wickstrand, Cecilia

2014-01-01

We describe a method to measure ultrafast protein structural changes using time-resolved wide-angle X-ray scattering at an X-ray free-electron laser. We demonstrated this approach using multiphoton excitation of the Blastochloris viridis photosynthetic reaction center, observing an ultrafast glob...

Time-resolved X-ray scattering by electronic wave packets: analytic solutions to the hydrogen atom

DEFF Research Database (Denmark)

Simmermacher, Mats; Henriksen, Niels Engholm; Møller, Klaus Braagaard

2017-01-01

Modern pulsed X-ray sources permit time-dependent measurements of dynamical changes in atoms and molecules via non-resonant scattering. The planning, analysis, and interpretation of such experiments, however, require a firm and elaborated theoretical framework. This paper provides a detailed...... description of time-resolved X-ray scattering by non-stationary electronic wave packets in atomic systems. A consistent application of the Waller-Hartree approximation is discussed and different contributions to the total differential scattering signal are identified and interpreted. Moreover......, it is demonstrated how the scattering signal of wave packets in the hydrogen atom can be expressed analytically. This permits simulations without numerical integration and establishes a benchmark for both efficiency and accuracy. Based on that, scattering patterns of an exemplary wave packet in the hydrogen atom...

Scatter and transmission doses from several pediatric X-ray examinations in a nursery

International Nuclear Information System (INIS)

Burrage, John W.; Rampant, Peter L.; Beeson, Brendan P.

2003-01-01

While several studies have investigated the dose from scattered radiation from X-ray procedures in a pediatric nursery, they examined scatter from chest procedures only, or the types of examination were not specified. The aim of this study was to collect scatter and transmission data from several types of X-ray examinations. Using a ''newborn'' anthropomorphic phantom and an ion chamber, a series of scatter and transmission dose measurements were performed using typical exposure factors for chest, chest and abdomen, skull, skeletal long bone and spine procedures. The phantom was inside a crib for all exposures. The maximum scatter dose measured at 1 m from the field center was about 0.05 μGy per exposure for lateral skulls. Transmission doses for lateral exams were around 0.1 μGy per exposure at 1 m from the isocenter. The study demonstrated that scatter dose to other patients in a neonatal unit is not significant, assuming the distance between adjacent cribs is in the order of 1 m. Transmission doses are also low provided the beam is fully intercepted by the cassette. For an average workload the dose received by imaging technologists would be small. (orig.)

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

Science.gov (United States)

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

2015-04-14

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

Resonant x-ray scattering in manganites: study of the orbital degree of freedom

International Nuclear Information System (INIS)

Ishihara, Sumio; Maekawa, Sadamichi

2002-01-01

The orbital degree of freedom of electrons and its interplay with spin, charge and lattice degrees of freedom are some of the central issues in colossal magnetoresistive manganites. The orbital degree of freedom has until recently remained hidden, since it does not couple directly to most experimental probes. Development of synchrotron light sources has changed the situation; by the resonant x-ray scattering (RXS) technique the orbital ordering has successfully been observed. In this article, we review progress in the recent studies of RXS in manganites. We start with a detailed review of the RXS experiments applied to the orbital-ordered manganites and other correlated electron systems. We derive the scattering cross section of RXS, where the tensor character of the atomic scattering factor (ASF) with respect to the x-ray polarization is stressed. Microscopic mechanisms of the anisotropic tensor character of the ASF are introduced and numerical results of the ASF and the scattering intensity are presented. The azimuthal angle scan is a unique experimental method to identify RXS from the orbital degree of freedom. A theory of the azimuthal angle and polarization dependence of the RXS intensity is presented. The theoretical results show good agreement with the experiments in manganites. Apart from the microscopic description of the ASF, a theoretical framework of RXS to relate directly to the 3d orbital is presented. The scattering cross section is represented by the correlation function of the pseudo-spin operator for the orbital degree of freedom. A theory is extended to the resonant inelastic x-ray scattering and methods to observe excitations of the orbital degree of freedom are proposed. (author)

Degradation of periodic multilayers as seen by small-angle x-ray scattering and x-ray diffraction

CERN Document Server

Rafaja, D; Simek, D; Zdeborova, L; Valvoda, V

2002-01-01

The capabilities of small-angle x-ray scattering (SAXS) and wide-angle x-ray diffraction (XRD) to recognize structural changes in periodic multilayers were compared on Fe/Au multilayers with different degrees of structural degradation. Experimental results have shown that both methods are equally sensitive to the multilayer degradation, i.e., to the occurrence of non-continuous interfaces, to short-circuits in the multilayer structure and to the multilayer precipitation. XRD yielded additional information on the multilayer crystallinity, whilst SAXS could better recognize fragments of a long-range periodicity (remnants of the original multilayer structure). Changes in the multilayer structure were initiated by successive annealing at 200 and 300 deg. C. Experimental data were complemented by numerical simulations performed using a combination of optical theory and the distorted wave Born approximation for SAXS or the kinematical Born approximation for XRD.

A software-based x-ray scatter correction method for breast tomosynthesis

International Nuclear Information System (INIS)

Jia Feng, Steve Si; Sechopoulos, Ioannis

2011-01-01

Purpose: To develop a software-based scatter correction method for digital breast tomosynthesis (DBT) imaging and investigate its impact on the image quality of tomosynthesis reconstructions of both phantoms and patients. Methods: A Monte Carlo (MC) simulation of x-ray scatter, with geometry matching that of the cranio-caudal (CC) view of a DBT clinical prototype, was developed using the Geant4 toolkit and used to generate maps of the scatter-to-primary ratio (SPR) of a number of homogeneous standard-shaped breasts of varying sizes. Dimension-matched SPR maps were then deformed and registered to DBT acquisition projections, allowing for the estimation of the primary x-ray signal acquired by the imaging system. Noise filtering of the estimated projections was then performed to reduce the impact of the quantum noise of the x-ray scatter. Three dimensional (3D) reconstruction was then performed using the maximum likelihood-expectation maximization (MLEM) method. This process was tested on acquisitions of a heterogeneous 50/50 adipose/glandular tomosynthesis phantom with embedded masses, fibers, and microcalcifications and on acquisitions of patients. The image quality of the reconstructions of the scatter-corrected and uncorrected projections was analyzed by studying the signal-difference-to-noise ratio (SDNR), the integral of the signal in each mass lesion (integrated mass signal, IMS), and the modulation transfer function (MTF). Results: The reconstructions of the scatter-corrected projections demonstrated superior image quality. The SDNR of masses embedded in a 5 cm thick tomosynthesis phantom improved 60%-66%, while the SDNR of the smallest mass in an 8 cm thick phantom improved by 59% (p < 0.01). The IMS of the masses in the 5 cm thick phantom also improved by 15%-29%, while the IMS of the masses in the 8 cm thick phantom improved by 26%-62% (p < 0.01). Some embedded microcalcifications in the tomosynthesis phantoms were visible only in the scatter

Temperature- and density-dependent x-ray scattering in a low-Z plasma

International Nuclear Information System (INIS)

Brown, R.T.

1976-06-01

A computer program is described which calculates temperature- and density-dependent differential and total coherent and incoherent x-ray scattering cross sections for a low-Z scattering medium. Temperature and density are arbitrary within the limitations of the validity of local thermodynamic equilbrium, since ionic populations are calculated under this assumption. Scattering cross sections are calculated in the form factor approximation. The scattering medium may consist of any mixure of elements with Z less than or equal to 8, with this limitation imposed by the availability of atomic data

Soft X-ray production by photon scattering in pulsating binary neutron star sources

International Nuclear Information System (INIS)

Bussard, R.W.; Meszaros, P.; Alexander, S.

1985-01-01

A new mechanism is proposed as a source of soft (less than 1 keV) radiation in binary pulsating X-ray sources, in the form of photon scattering which leaves the electron in an excited Landau level. In a plasma with parameters typical of such sources, the low-energy X-ray emissivity of this mechanism far exceeds that of bremsstrahlung. This copious source of soft photons is quite adequate to provide the seed photons needed to explain the power-law hard X-ray spectrum by inverse Comptonization on the hot electrons at the base of the accretion column. 13 references

X-ray scattering studies of non-equilibrium ordering processes

International Nuclear Information System (INIS)

Nagler, S.E.

1992-01-01

This report summarizes the major results obtained under US DOE Grant Number FG05-90ER45280 from the dates November 1, 1989 through October 31, 1992 inclusive. The principal work includes x-ray scattering studies of phase transition kinetics in binary alloy order-disorder transitions, block co-polymer crystallization, and charge density wave solids under applied electric fields, and studies of magnetic excitations in low dimensional quantum systems

Building a Unified Computational Model for the Resonant X-Ray Scattering of Strongly Correlated Materials

International Nuclear Information System (INIS)

Bansil, Arun

2016-01-01

Basic-Energy Sciences of the Department of Energy (BES/DOE) has made large investments in x-ray sources in the U.S. (NSLS-II, LCLS, NGLS, ALS, APS) as powerful enabling tools for opening up unprecedented new opportunities for exploring properties of matter at various length and time scales. The coming online of the pulsed photon source literally allows us to see and follow the dynamics of processes in materials at their natural timescales. There is an urgent need therefore to develop theoretical methodologies and computational models for understanding how x-rays interact with matter and the related spectroscopies of materials. The present project addressed aspects of this grand challenge of X-ray science. In particular, our Collaborative Research Team (CRT) focused on understanding and modeling of elastic and inelastic resonant X-ray scattering processes. We worked to unify the three different computational approaches currently used for modeling X-ray scattering-density functional theory, dynamical mean-field theory, and small-cluster exact diagonalization-to achieve a more realistic material-specific picture of the interaction between X-rays and complex matter. To achieve a convergence in the interpretation and to maximize complementary aspects of different theoretical methods, we concentrated on the cuprates, where most experiments have been performed. Our team included both US and international researchers, and it fostered new collaborations between researchers currently working with different approaches. In addition, we developed close relationships with experimental groups working in the area at various synchrotron facilities in the US. Our CRT thus helped toward enabling the US to assume a leadership role in the theoretical development of the field, and to create a global network and community of scholars dedicated to X-ray scattering research.

Small angle X-ray scattering experiments with three-dimensional imaging gas detectors

International Nuclear Information System (INIS)

La Monaca, A.; Iannuzzi, M.; Messi, R.

1985-01-01

Measurements of small angle X-ray scattering of lupolen - R, dry collagen and dry cornea are presented. The experiments have been performed with synchrotron radiation and a new three-dimensional imaging drif-chamber gas detector

Progresses in the measurement and evaluation of small-angle x-ray scattering data

International Nuclear Information System (INIS)

Bergmann, A.

2000-08-01

Scattering methods are a widely used technique for determining size and shape of particles in the mesoscopic size range. This work deals on the one hand with the development of instruments in the field of Small Angle x-ray Scattering (SAXS) and on the other hand with methodical contributions concerning the interpretation of small angle scattering data. After a short introduction about Small Angle Scattering (SAS) and its application in chapter one, follows in chapter two a derivation of the theory of Small Angle x-ray scattering. Thereafter indirect transformations (Generalized Indirect Fourier Transformation [GIFT], Indirect Fourier Transformation [IFT]) are discussed and in this connection the optimization of multidimensional hyper surfaces is described. There are different possibilities for optimizing such multidimensional surfaces. The pros and contras of the different optimization methods with respect to the evaluation of small angle scattering data from interacting systems are discussed in detail. Global optimization methods are mainly used, if the hypersurface, which has to be optimized, shows many local minima. The goal of the optimization is it to find the global minimum. It is essential, that the parameters of the hyper surface are independent of each other, as it is the case in the GIFT. If someone deals with problems in only few dimensions or with many boundary conditions, mostly local optimization routines are sufficient. Therefore a number of starting parameters for the optimization is chosen, which can be obtained systematically or randomly. The best solution obtained represents the result of the optimization procedure. Chapter 3 deals with the description of instruments used in the field of Small Angle x-ray Scattering. After a description of the components (x-ray sources, monochromators, detectors) of these instruments, the different beam geometries are discussed. In chapter 4 improvements of SAXS measurements on Kratky slit systems by Goebel

Dynamical X-ray scattering from the relaxed structures

International Nuclear Information System (INIS)

Benediktovitch, A.; Feranchuk, I.; Ulyanenkov, A.

2009-01-01

High-resolution X-ray diffraction is now widely used analytical tool for investigation of nano scale multilayered structures in semiconductor and optical technologies. The HRXRD method delivers unique information on the crystallographic lattice of the samples, concentration of solid solutions, lattice mismatches, layer thicknesses, defect distribution, and relaxation degree of the epitaxial layers. The evaluation of the experimental results, however, requires a robust and precise theory due to complex dynamical scattering of X-rays from near perfect crystallographic structure of the samples. Usually, the Takagi-Taupin approach [1] or the recurrent matrix methods [2] are used for the simulation of the X-ray diffraction profiles from the epitaxial multilayered structures. The use of these theories, however, becomes essentially difficult, when the lateral lattice mismatches are present in multilayers, for example, in the case of partially or fully relaxed epitaxially grown samples. In the present work, the general solution of this problem is found analytically. The angular divergence of the incident beam is also considered and the algorithm for the diffracted profile mapping in the reciprocal space is developed. The experimental reciprocal space mapping of typical AlGaN/GaN/AlN samples with partially relaxed layers is compared to the simulated maps, which describe well the location and character of the diffraction spots caused by different layers. (author)

Monte Carlo simulation of photon scattering in x-ray absorption imaging of high-intensity discharge lamps

Energy Technology Data Exchange (ETDEWEB)

Curry, J J, E-mail: jjcurry@nist.go [National Institute of Standards and Technology, Gaithersburg, MD 20899-8422 (United States)

2010-06-16

Coherent and incoherent scattering of x-rays during x-ray absorption imaging of high-intensity discharge lamps have been studied with Monte Carlo simulations developed specifically for this purpose. The Monte Carlo code is described and some initial results are discussed. Coherent scattering, because of its angular concentration in the forward direction, is found to be the most significant scattering mechanism. Incoherent scattering, although comparably strong, is not as significant because it results primarily in photons being scattered in the rearward direction and therefore out of the detector. Coherent scattering interferes with the detected absorption signal because the path of a scattered photon through the object to be imaged is unknown. Although scattering is usually a small effect, it can be significant in regions of high contrast. At the discharge/wall interface, as many as 50% of the detected photons are scattered photons. The effect of scattering on analysis of Hg distributions has not yet been quantified.

Study of the grazing-incidence X-ray scattering of strongly disturbed fractal surfaces

Energy Technology Data Exchange (ETDEWEB)

Roshchin, B. S., E-mail: ross@crys.ras.ru; Chukhovsky, F. N.; Pavlyuk, M. D.; Opolchentsev, A. M.; Asadchikov, V. E. [Russian Academy of Sciences, Shubnikov Institute of Crystallography, Federal Research Centre “Crystallography and Photonics” (Russian Federation)

2017-03-15

The applicability of different approaches to the description of hard X-ray scattering from rough surfaces is generally limited by a maximum surface roughness height of no more than 1 nm. Meanwhile, this value is several times larger for the surfaces of different materials subjected to treatment, especially in the initial treatment stages. To control the roughness parameters in all stages of surface treatment, a new approach has been developed, which is based on a series expansion of wavefield over the plane eigenstate-function waves describing the small-angle scattering of incident X-rays in terms of plane q-waves propagating through the interface between two media with a random function of relief heights. To determine the amplitudes of reflected and transmitted plane q-waves, a system of two linked integral equations was derived. The solutions to these equations correspond (in zero order) to the well-known Fresnel expressions for a smooth plane interface. Based on these solutions, a statistical fractal model of an isotropic rough interface is built in terms of root-mean-square roughness σ, two-point correlation length l, and fractal surface index h. The model is used to interpret X-ray scattering data for polished surfaces of single-crystal cadmium telluride samples.

The performance test of anti-scattering x-ray grid with inclined shielding material by MCNP code simulation

Energy Technology Data Exchange (ETDEWEB)

Bae, Jun Woo; Kim, Hee Reyoung [Ulsan National Institute of Science and Technology, Ulsan (Korea, Republic of)

2016-06-15

The scattered photons cause reduction of the contrast of radiographic image and it results in the degradation of the quality of the image. In order to acquire better quality image, an anti-scattering x-ray gird should be equipped in radiography system. The X-ray anti-scattering grid of the inclined type based on the hybrid concept for that of parallel and focused type was tested by MCNP code. The MCNPX 2.7.0 was used for the simulation based test. The geometry for the test was based on the IEC 60627 which was an international standard for diagnostic X-ray imaging equipment-Characteristics of general purpose and mammographic anti-scatter grids. The performance of grids with four inclined shielding material types was compared with that of the parallel type. The grid with completely tapered type the best performance where there were little performance difference according to the degree of inclination.

X-ray resonant Raman scattering cross sections of Mn, Fe, Cu and Zn

International Nuclear Information System (INIS)

Sanchez, Hector Jorge; Valentinuzzi, MarIa Cecilia; Perez, Carlos

2006-01-01

X-ray fluorescence spectra present singular characteristics produced by the different scattering processes. When atoms are irradiated with incident energy lower and close to an absorption edge, scattering peaks appear due to an inelastic process known as resonant Raman scattering. It constitutes an important contribution to the background of the fluorescent line. The resonant Raman scattering must be taken into account in the determination of low concentration contaminants, especially when the elements have proximate atomic numbers. The values of the mass attenuation coefficients experimentally obtained when materials are analysed with monochromatic x-ray beams under resonant conditions differ from the theoretical values (between 5% and 10%). This difference is due, in part, to the resonant Raman scattering. Monochromatic synchrotron radiation was used to study the Raman effect on pure samples of Mn, Fe, Cu and Zn. Energy scans were carried out in different ranges of energy near the absorption edge of the target element. As the Raman peak has a non-symmetric shape, theoretical models for the differential cross section, convoluted with the instrument function, were used to determine the RRS cross section as a function of the incident energy

Buffer-induced swelling and vesicle budding in binary lipid mixtures of dioleoylphosphatidylcholine:dioleoylphosphatidylethanolamine and dioleoylphosphatidylcholine:lysophosphatidylcholine using small-angle X-ray scattering and ³¹P static NMR.

Science.gov (United States)

Barriga, Hanna M G; Bazin, Richard; Templer, Richard H; Law, Robert V; Ces, Oscar

2015-03-17

A large variety of data exists on lipid phase behavior; however, it is mostly in nonbuffered systems over nonbiological temperature ranges. We present biophysical data on lipid mixtures of dioleoylphosphatidylcholine (DOPC), dioleoylphosphatidylethanolamine (DOPE), and lysophosphatidylcholine (LysoPC) examining their behaviors in excess water and buffer systems over the temperature range 4-34 °C. These mixtures are commonly used to investigate the effects of spontaneous curvature on integral membrane proteins. Using small-angle X-ray scattering (SAXS) and (31)P NMR, we observed lamellar and vesicle phases, with the buffer causing an increase in the layer spacing. Increasing amounts of DOPE in a DOPC bilayer decreased the layer spacing of the mesophase, while the opposite trend was observed for increasing amounts of LysoPC. (31)P static NMR was used to analyze the DOPC:LysoPC samples to investigate the vesicle sizes present, with evidence of vesicle budding observed at LysoPC concentrations above 30 mol %. NMR line shapes were fitted using an adapted program accounting for the distortion of the lipids within the magnetic field. The distortion of the vesicle, because of magnetic susceptibility, varied with LysoPC content, and a discontinuity was found in both the water and buffer samples. Generally, the distortion increased with LysoPC content; however, at a ratio of DOPC:LysoPC 60:40, the sample showed a level of distortion of the vesicle similar to that of pure DOPC. This implies an increased flexibility in the membrane at this point. Commonly, the assumption is that for increasing LysoPC concentration there is a reduction in membrane tension, implying that estimations of membrane tension based on spontaneous curvature assumptions may not be accurate.

XUV and x-ray elastic scattering of attosecond electromagnetic pulses on atoms

Science.gov (United States)

Rosmej, F. B.; Astapenko, V. A.; Lisitsa, V. S.

2017-12-01

Elastic scattering of electromagnetic pulses on atoms in XUV and soft x-ray ranges is considered for ultra-short pulses. The inclusion of the retardation term, non-dipole interaction and an efficient scattering tensor approximation allowed studying the scattering probability in dependence of the pulse duration for different carrier frequencies. Numerical calculations carried out for Mg, Al and Fe atoms demonstrate that the scattering probability is a highly nonlinear function of the pulse duration and has extrema for pulse carrier frequencies in the vicinity of the resonance-like features of the polarization charge spectrum. Closed expressions for the non-dipole correction and the angular dependence of the scattered radiation are obtained.

A library for X-ray-matter interaction cross sections for X-ray fluorescence applications

Energy Technology Data Exchange (ETDEWEB)

Brunetti, A. [Istituto di Matematica e Fisica, Universita di Sassari, via Vienna 2, 07100 Sassari (Italy) and INFN, Sezione di Cagliari (Italy)]. E-mail: brunetti@uniss.it; Sanchez del Rio, M. [European Synchrotron Radiation Facility, 6 rue Jules Horowitz, 38043 Grenoble Cedex (France); Golosio, B. [INFN, Sezione di Cagliari (Italy); European Synchrotron Radiation Facility, 6 rue Jules Horowitz, 38043 Grenoble Cedex (France); Simionovici, A. [European Synchrotron Radiation Facility, 6 rue Jules Horowitz, 38043 Grenoble Cedex (France); Laboratoire de Sciences de la Terre, Ecole Normale Superieure, Lyon, F-69364 (France); Somogyi, A. [European Synchrotron Radiation Facility, 6 rue Jules Horowitz, 38043 Grenoble Cedex (France)

2004-10-08

Quantitative estimate of elemental composition by spectroscopic and imaging techniques using X-ray fluorescence requires the availability of accurate data of X-ray interaction with matter. Although a wide number of computer codes and data sets are reported in literature, none of them is presented in the form of freely available library functions which can be easily included in software applications for X-ray fluorescence. This work presents a compilation of data sets from different published works and an xraylib interface in the form of callable functions. Although the target applications are on X-ray fluorescence, cross sections of interactions like photoionization, coherent scattering and Compton scattering, as well as form factors and anomalous scattering functions, are also available.

Recent developments in X-ray and neutron small-angle scattering instrumentation and data analysis

International Nuclear Information System (INIS)

Schelten, J.

1978-01-01

The developments in instrumentation and data analysis that have occurred in the field of small-angle X-ray and neutron scattering since 1973 are reviewed. For X-rays, the cone camera collimation was invented, synchrotrons and storage rings were demonstrated to be intense sources of X-radiation, and one- and two-dimensional position-sensitive detectors were interfaced to cameras with both point and line collimation. For neutrons, the collimators and detectors on the Juelich and Grenoble machines were improved, new D11-type instruments were built or are under construction at several sites, double-crystal instruments were set up, and various new machines have been proposed. Significant progress in data analysis and evaluation has been made through application of mathematical techniques such as the use of spline functions, error minimization with constraints, and linear programming. Several special experiments, unusual in respect to the anisotropy of the scattering pattern, gravitational effects, moving scatterers, and dynamic fast time slicing, are discussed. (Auth.)

Small-angle scattering of polychromatic X-rays: effects of bandwidth, spectral shape and high harmonics

Energy Technology Data Exchange (ETDEWEB)

Chen, Sen; Luo, Sheng-Nian

2018-02-16

Polychromatic X-ray sources can be useful for photon-starved small-angle X-ray scattering given their high spectral fluxes. Their bandwidths, however, are 10–100 times larger than those using monochromators. To explore the feasibility, ideal scattering curves of homogeneous spherical particles for polychromatic X-rays are calculated and analyzed using the Guinier approach, maximum entropy and regularization methods. Monodisperse and polydisperse systems are explored. The influence of bandwidth and asymmetric spectra shape are exploredviaGaussian and half-Gaussian spectra. Synchrotron undulator spectra represented by two undulator sources of the Advanced Photon Source are examined as an example, as regards the influence of asymmetric harmonic shape, fundamental harmonic bandwidth and high harmonics. The effects of bandwidth, spectral shape and high harmonics on particle size determination are evaluated quantitatively.

Small-angle scattering of polychromatic X-rays: effects of bandwidth, spectral shape and high harmonics.

Science.gov (United States)

Chen, Sen; Luo, Sheng Nian

2018-03-01

Polychromatic X-ray sources can be useful for photon-starved small-angle X-ray scattering given their high spectral fluxes. Their bandwidths, however, are 10-100 times larger than those using monochromators. To explore the feasibility, ideal scattering curves of homogeneous spherical particles for polychromatic X-rays are calculated and analyzed using the Guinier approach, maximum entropy and regularization methods. Monodisperse and polydisperse systems are explored. The influence of bandwidth and asymmetric spectra shape are explored via Gaussian and half-Gaussian spectra. Synchrotron undulator spectra represented by two undulator sources of the Advanced Photon Source are examined as an example, as regards the influence of asymmetric harmonic shape, fundamental harmonic bandwidth and high harmonics. The effects of bandwidth, spectral shape and high harmonics on particle size determination are evaluated quantitatively.

Development study of the X-ray scattering properties of a group of optically polished flat samples

Science.gov (United States)

Froechtenigt, J. F.

1973-01-01

A group of twelve optically polished flat samples were used to study the scattering of X-rays. The X-ray beam reflected from the twelve optical flat samples was analyzed by means of a long vacuum system of special design for these tests. The scattering measurements were made at 8.34A and 0.92 deg angle of incidence. The results for ten of the samples are comparable, the two exceptions being the fire polished samples.

Data Analysis Of Small Angle X-Ray Solution Scattering And Its ...

African Journals Online (AJOL)

Small Angle X-ray Scattering analysis was used for the study of the protein, Human Tumour Necrosis Factor (TNF) homogeneously dispersed in solution. The experiment consisted in sending a well collimated beam of synchrotron radiation of wavelength, λ through the sample and measuring the variation of the intensity as a ...

1s2p resonant inelastic x-ray scattering in a-Fe2O3

NARCIS (Netherlands)

Caliebe, W.A.; Kao, C.-C.; Hastings, J.B.; Taguchi, M.; Kotani, A.; Uozumi, T.; Groot, F.M.F. de

1998-01-01

We report experimental and theoretical results on the Fe K edge x-ray absorption spectrum and 1s2p resonant inelastic x-ray scattering (RIXS) spectra in a-Fe2O3 . The results are interpreted using an FeO6^9- cluster model with intra-atomic multiplet coupling and interatomic covalency

Use of a solar panel as a directionally sensitive large-area radiation monitor for direct and scattered x-rays and gamma-rays.

Science.gov (United States)

Abdul-Majid, S

1987-01-01

The characteristics of a 25.4 X 91 cm solar cell panel used as an x-ray and gamma-ray radiation monitor are presented. Applications for monitoring the primary x-ray beam are described at different values of operating currents and voltages as well as for directional dependence of scattered radiation. Other applications in gamma-ray radiography are also given. The detector showed linear response to both x-ray and gamma-ray exposures. The equipment is rigid, easy to use, relatively inexpensive and requires no power supply or any complex electronic equipment.

Watching Nanoparticles Form: An In Situ (Small-/Wide-Angle X-ray Scattering/Total Scattering) Study of the Growth of Yttria-Stabilised Zirconia in Supercritical Fluids

DEFF Research Database (Denmark)

Tyrsted, Christoffer; Pauw, Brian; Jensen, Kirsten Marie Ørnsbjerg

2012-01-01

Understanding nanoparticle formation reactions requires multitechnique in situ characterisation, since no single characterisation technique provides adequate information. Here, the first combined small-angle X-ray scattering (SAXS)/wide-angle X-ray scattering (WAXS)/total-scattering study of nano...... of nanoparticle formation is presented. We report on the formation and growth of yttria-stabilised zirconia (YSZ) under the extreme conditions of supercritical methanol for particles with Y2O3 equivalent molar fractions of 0, 4, 8, 12 and 25%....

Compact X-ray sources: X-rays from self-reflection

Science.gov (United States)

Mangles, Stuart P. D.

2012-05-01

Laser-based particle acceleration offers a way to reduce the size of hard-X-ray sources. Scientists have now developed a simple scheme that produces a bright flash of hard X-rays by using a single laser pulse both to generate and to scatter an electron beam.

K-edge resonant x-ray magnetic scattering from a transition-metal oxide: NiO

DEFF Research Database (Denmark)

Hill, J.P.; Kao, C.C.; McMorrow, D.F.

1997-01-01

We report the observation of resonant x-ray magnetic scattering in the vicinity of the Ni K edge in the antiferromagnet NiO. An approximately twofold increase in the scattering is observed as the incident photon energy is tuned through a pre-edge feature in the absorption spectrum, associated...

Status of Kharkov X-Ray Generator Based on Compton Scattering NESTOR

Energy Technology Data Exchange (ETDEWEB)

Zelinsky, A.

2005-04-11

Nowadays the sources of the X-rays based on a storage ring with low beam energy and Compton scattering of intense laser beam are under development in several laboratories. In the paper the state-of-art in development and construction of cooperative project of a Kharkov advanced X-ray source NESTOR based on electron storage ring with beam energy 43-225 MeV and Nd:YAG laser is described. The layout of the facility is presented and latest results are described. The designed lattice includes 4 dipole magnets with combined focusing functions, 20 quadrupole magnets and 19 sextupoles with correcting components of magnetic field. At the present time a set of quadrupole magnet is under manufacturing and bending magnet reconstruction is going on. The main parameters of developed vacuum system providing residual gas pressure in the storage ring vacuum chamber up to 10{sup -9} torr are presented. The basic parameters of the X-ray source laser and injection systems are presented. The facility is going to be in operation in the middle of 2006 and generated X-rays flux is expected to be of about 10{sup 13} phot/s.

Resonant X-ray Scattering of carbonyl sulfide at the sulfur K edge

International Nuclear Information System (INIS)

Journel, Loïc; Marchenko, Tatiana; Guillemin, Renaud; Kawerk, Elie; Simon, Marc; Kavčič, Matjaž; Žit-nik, Matjaž; Bučar, Klemen; Bohinc, Rok

2015-01-01

New results on free OCS molecules have been obtained using Resonant X-ray Inelastic Scattering spectroscopy. A deconvolution algorithm has been applied to improve the energy resolution spectra of which we can extract detailed information on nuclear dynamics in the system. (paper)

Resonant X-ray Scattering of carbonyl sulfide at the sulfur K edge

OpenAIRE

Journel , Loïc; Marchenko , Tatiana; Guillemin , Renaud; Kawerk , Elie; Kavčič , Matjaž; Žit-nik , Matjaž; Bučar , Klemen; Bohinc , Rok; Simon , Marc

2015-01-01

International audience; New results on free OCS molecules have been obtained using Resonant X-ray Inelastic Scattering spectroscopy. A deconvolution algorithm has been applied to improve the energy resolution spectra of which we can extract detailed information on nuclear dynamics in the system.

X-ray electromagnetic application technology

International Nuclear Information System (INIS)

2011-01-01

The investigating committee aimed at research on electromagnetic fields in functional devices and X-ray fibers for efficient coherent X-ray generation and their material science, high-precision manufacturing, particularly for X-ray electromagnetic application technology from January 2006 to December 2008. In this report, we describe our research results, in particular, on the topics of synchrotron radiation and free-electron laser, Saga Synchrotron Project, X-ray waveguides and waveguide-based lens-less hard-X-ray imaging, X-ray nanofocusing for capillaries and zone plates, dispersion characteristics in photonics crystal consisting of periodic atoms for nanometer waveguides, electromagnetic characteristics of grid structures for scattering fields of nano-meter electromagnetic waves and X-rays, FDTD parallel computing of fundamental scattering and attenuation characteristics of X-ray for medical imaging diagnosis, orthogonal relations of electromagnetic fields including evanescent field in dispersive medium. (author)

Monitoring the recrystallisation of amorphous xylitol using Raman spectroscopy and wide-angle X-ray scattering.

Science.gov (United States)

Palomäki, Emmi; Ahvenainen, Patrik; Ehlers, Henrik; Svedström, Kirsi; Huotari, Simo; Yliruusi, Jouko

2016-07-11

In this paper we present a fast model system for monitoring the recrystallization of quench-cooled amorphous xylitol using Raman spectroscopy and wide-angle X-ray scattering. The use of these two methods enables comparison between surface and bulk crystallization. Non-ordered mesoporous silica micro-particles were added to the system in order to alter the rate of crystallization of the amorphous xylitol. Raman measurements showed that adding silica to the system increased the rate of surface crystallization, while X-ray measurements showed that the rate of bulk crystallization decreased. Using this model system it is possible to measure fast changes, which occur in minutes or within a few hours. Raman-spectroscopy and wide-angle X-ray scattering were found to be complementary techniques when assessing surface and bulk crystallization of amorphous xylitol. Copyright © 2016 Elsevier B.V. All rights reserved.

Power spectrum analysis of the x-ray scatter signal in mammography and breast tomosynthesis projections.

Science.gov (United States)

Sechopoulos, Ioannis; Bliznakova, Kristina; Fei, Baowei

2013-10-01

To analyze the frequency domain characteristics of the signal in mammography images and breast tomosynthesis projections with patient tissue texture due to detected scattered x-rays. Acquisitions of x-ray projection images of 19 different patient breasts were simulated using previously acquired volumetric patient images. Acquisition of these images was performed with a dedicated breast CT prototype system, and the images were classified into voxels representing skin, adipose, and glandular tissue with a previously validated automated algorithm. The classified three dimensional images then underwent simulated mechanical compression representing that which is performed during acquisition of mammography and breast tomosynthesis images. The acquisition of projection images of each patient breast was simulated using Monte Carlo methods with each simulation resulting in two images: one of the primary (non-scattered) signal and one of the scatter signal. To analyze the scatter signal for both mammography and breast tomosynthesis, two projections images of each patient breast were simulated, one with the x-ray source positioned at 0° (mammography and central tomosynthesis projection) and at 30° (wide tomosynthesis projection). The noise power spectra (NPS) for both the scatter signal alone and the total signal (primary + scatter) for all images were obtained and the combined results of all patients analyzed. The total NPS was fit to the expected power-law relationship NPS(f) = k/f β and the results were compared with those previously published on the power spectrum characteristics of mammographic texture. The scatter signal alone was analyzed qualitatively and a power-law fit was also performed. The mammography and tomosynthesis projections of three patient breasts were too small to analyze, so a total of 16 patient breasts were analyzed. The values of β for the total signal of the 0° projections agreed well with previously published results. As expected, the scatter

X-ray scattering on liquid-gas interfaces; Roentgenstreuung an Fluessigkeits-Gas Grenzflaechen

Energy Technology Data Exchange (ETDEWEB)

Paulus, Michael

2006-07-01

In the framework of this thesis two different theme-fields were studied with dhe methods of the elastic, surface sensitive X-ray scattering. In the first part of the thesis the liquid-gas interfaces water-propane and glycerol-isobutane were studied concerning the structure formation on these interfaces. The system water-propane served for the study of the gas hydrate formation on the water-gas interface. Studies on this interface could give no hints on the formation of propane hydrates or propane-hydrate fragments. However the adsorption of molecularly thin propane films on the water surface was observed. The adsorption behaviour of gases on liquid surfaces was studied by further experiments on the glycerol-isobutane interface. In the second part of the thesis the surfaces of aqueous salt solutions and water were studied. The lateralstructure of these liquid-gas interfaces was studied by the method of the diffuse X-ray scattering.

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

Directory of Open Access Journals (Sweden)

S.Hosokawa

2008-03-01

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

Low angle X-ray scattering in biological tissues

International Nuclear Information System (INIS)

Lemos, Carla; Braz, Delson; Pinto, Nivia G.V.; Lima, Joao C.; Castro, Carlos R.F.; Filgueiras, R.A.; Mendonca, Leonardo; Lopes, Ricardo T.; Barroso, Regina C.

2007-01-01

Low-angle x-ray scatter (LAXS) for tissue characterization is based on the differences which result from the interference of photons coherently scattered from molecules of each sample. Biological samples (bone, blood and blood components) have been studied in recent years in our laboratory using powder diffractometer. The scattering information was obtained using a Shimadzu DRX 6000 diffractometer at the Nuclear Instrumentation Laboratory, Rio de Janeiro, Brazil. Unpolarized monoenergetic Kα radiation from Cu provided 8.04 keV photons. The measurements were made in reflection mode (θ-2θ geometry), with the sample stationary on a goniometer which rotates the sample and detector about an axis lying in the plane of the top of the sample holder. LAXS profiles from whole blood, plasma and formed elements were measured to investigate the nature of scattering from such lyophilized samples. The statistical analysis shows that the variation found for the characterization parameters is significant for whole blood considering the age. Gender was positively associated with the variation of the second peak position for the profiles obtained for formed elements. The correlation of the measured relative coherent intensity with the mineral content in the bone samples was investigated. These results suggest that the measurement of bone mineral content within trabecular bone can be performed by using quantitative coherent scattering information. (author)

X-ray and neutron scattering investigations of YCo sub 3 -H

Energy Technology Data Exchange (ETDEWEB)

Benham, M J; Bennington, S M; Ross, D K [Birmingham Univ. (UK). School of Physics and Space Research; Noreus, D [Stockholm Univ. (Sweden). Dept. of Structural Chemistry; Yamaguchi, M [Yokohoma National Univ. (Japan). Dept. of Electrical and Computer Engineering

1989-01-01

Various structural studies of YCo{sub 3}H(D){sub x} in the {beta}-phase (0<x<2) are described, where hydrogenation induces a cyclic variation between ferromagnetic and paramagnetic states. X-ray diffraction measurements determined that the expansion of the lattice is localised to components of the structure which are related to the Laves phase, YCo{sub 2}. Neutron diffraction and inelastic neutron scattering were also used in tandem, and hydrogen occupation of a single (36i) tetrahedral site was inferred for the entire concentration range. (orig.).

Scatter fractions from linear accelerators with x-ray energies from 6 to 24 MV.

Science.gov (United States)

Taylor, P L; Rodgers, J E; Shobe, J

1999-08-01

Computation of shielding requirements for a linear accelerator must take into account the amount of radiation scattered from the patient to areas outside the primary beam. Currently, the most frequently used data are from NCRP 49 that only includes data for x-ray energies up to 6 MV and angles from 30 degrees to 135 degrees. In this work we have determined by Monte Carlo simulation the scattered fractions of dose for a wide range of energies and angles of clinical significance including 6, 10, 18, and 24 MV and scattering angles from 10 degrees to 150 degrees. Calculations were made for a 400 cm2 circular field size impinging onto a spherical phantom. Scattered fractions of dose were determined at 1 m from the phantom. Angles from 10 degrees to 30 degrees are of concern for higher energies where the scatter is primarily in the forward direction. An error in scatter fraction may result in too little secondary shielding near the junction with the primary barrier. The Monte Carlo code ITS (Version 3.0) developed at Sandia National Laboratory and NIST was used to simulate scatter from the patient to the barrier. Of significance was the variation of calculated scattered dose with depth of measurement within the barrier indicating that accurate values may be difficult to obtain. Mean energies of scatter x-ray spectra are presented.

Identification of human breast pathologies by X-ray elastic scattering; Identificacao de patologias mamarias atraves do espalhamento elastico de raios X

Energy Technology Data Exchange (ETDEWEB)

Conceicao, Andre L.C.; Antoniassi, Marcelo; Poletti, Martin E., E-mail: andre_conceicao@yahoo.com.b [Universidade de Sao Paulo (FFCLRP/USP), Ribeirao Preto, SP (Brazil). Faculdade de Filosofia, Ciencias e Letras. Dept. de Fisica e Matematica

2011-07-01

In this paper we determine the scattering profiles of normal, benign and malignant human breast samples in a momentum transfer range of 0.07nm{sup -1} {<=}q{<=}70.55nm{sup -1}, resulted from combining WAXS (wide angle x-ray scattering) and SAXS (small angle x-ray scattering) data. The results showed considerable differences between the scattering profiles of each tissue type. Based on this fact, some parameters, representing structural features, were extracted from these scattering profiles and submitted to a discriminant analysis. From statistical analysis, the ratio between the peak intensities at q=19.8nm{sup -1} and q=13.9nm{sup -1} and the intensity of third order axial collagen peak arose as two potentials breast tissue classifiers and, from combining them it was possible differentiate among normal, benign and malignant lesions. (author)

Simulated x-ray scattering of protein solutions using explicit-solvent models

International Nuclear Information System (INIS)

Park, Sanghyun; Bardhan, Jaydeep P.; Makowski, Lee; Roux, Benoit

2009-01-01

X-ray solution scattering shows new promise for the study of protein structures, complementing crystallography and nuclear magnetic resonance. In order to realize the full potential of solution scattering, it is necessary to not only improve experimental techniques but also develop accurate and efficient computational schemes to relate atomistic models to measurements. Previous computational methods, based on continuum models of water, have been unable to calculate scattering patterns accurately, especially in the wide-angle regime which contains most of the information on the secondary, tertiary, and quaternary structures. Here we present a novel formulation based on the atomistic description of water, in which scattering patterns are calculated from atomic coordinates of protein and water. Without any empirical adjustments, this method produces scattering patterns of unprecedented accuracy in the length scale between 5 and 100 A, as we demonstrate by comparing simulated and observed scattering patterns for myoglobin and lysozyme.

Preliminary small-angle X-ray scattering and X-ray diffraction studies of the BTB domain of lola protein from Drosophila melanogaster

Science.gov (United States)

Boyko, K. M.; Nikolaeva, A. Yu.; Kachalova, G. S.; Bonchuk, A. N.; Dorovatovskii, P. V.; Popov, V. O.

2017-11-01

The Drosophila genome has several dozens of transcription factors (TTK group) containing BTB domains assembled into octamers. The LOLA protein belongs to this family. The purification, crystallization, and preliminary X-ray diffraction and small-angle X-ray scattering (SAXS) studies of the BTB domain of this protein are reported. The crystallization conditions were found by the vapor-diffusion technique. A very low diffraction resolution (8.7 Å resolution) of the crystals was insufficient for the determination of the threedimensional structure of the BTB domain. The SAXS study demonstrated that the BTB domain of the LOLA protein exists as an octamer in solution.

Dichroism and resonant diffraction in x-ray scattering by complex materials

International Nuclear Information System (INIS)

Collins, S P; Lovesey, S W; Balcar, E

2007-01-01

We survey universal concepts that influence dichroism and resonant Bragg diffraction, aiming to reach across the range of scientific disciplines that benefit from x-ray techniques, namely, chemistry, physics, life-sciences, and the science of materials. To this end, we adopt a top down discussion of the aspects of symmetry and concomitant selection rules. Starting from selection rules that can be deduced from the global condition that an observable quantity is unchanged on reversing the directions of both space and time separately, to selection rules that flow from bulk symmetry properties of electrons imposed by elements of a point group or crystal class to, finally, atomic selection rules that emerge from the details of the electronic structure. As a motivation for the latter we discuss, with a new calculation of the x-ray scattering length, E 1-M 1 absorption and scattering events that particularly interest scientists studying the chirality of life. In the main text there is modest use of mathematics, with appropriate details relegated to a few appendices. (topical review)

Measurement of x-ray scattering cross sections of hydrogen and helium with synchrotron radiation

International Nuclear Information System (INIS)

Ice, G.E.

1977-01-01

Total x-ray scattering is a two-electron expectation value. The prominence of the electron correlation effect was demonstrated in recent theoretical work. Only one measurement of x-ray scattering from H 2 has been reported heretofore, nearly fifty years ago. New measurements were carried out using the virtually monochromatic, intense flux of synchrotron radiation in the SSRP EXAFS line. The targets, at 1 atm pressure, were UHP He and ultrapure H 2 that had been passed through a hot Pd--Ag alloy diffusion purifier. The scattered-photon spectra were measured with a Xe-filled proportional counter and fast multichannel analyzer. The incident flux was monitored with a parallel-plate ion chamber, calibrated by direct counting of the absorber-attenuated beam. Measurements were performed at 5, 6, and 7 keV photon energy, as a function of scattering angle (60, 90, and 135 deg) and azimuthal angle (i.e., polarization). The relative total differential photon scattering cross sections for H 2 over the range 3.0 less than or equal to x = 4πsin (theta/2)lambda less than or equal to 5.6 A -1 agree to within approx. 1% with the correlated calculations of Bentley and Stewart. The ratios of measured cross sections for H 2 to those for He at x = 3.0 and 5.6 A -1 agree to within 1% with the ratios of the Bentley--Stewart H 2 cross sections to the correlated wave-function calculations of Brown for He

Anomalous X-ray scattering studies on semiconducting and metallic glasses

International Nuclear Information System (INIS)

Hosokawa, S.; Pilgrim, W.C.; Berar, J.F.; Kohara, S.

2012-01-01

In order to explore local- and intermediate-range atomic structures of several semiconducting and metallic glasses, anomalous X-ray scattering (AXS) experiments were performed using an improved detecting system suitable for third-generation synchrotron radiation facilities, and the obtained data were analyzed using reverse Monte Carlo (RMC) modelling to obtain partial structure factors and to construct three-dimensional atomic configurations of these glasses. Examples of GeSe 2 semiconducting and Pd 40 Ni 40 P 20 metallic glasses are demonstrated to exhibit the feasibility of the combination of AXS and RMC techniques. Importance of an additional combination with neutron scattering is also described for alloys containing light elements. (authors)

Small-angle x-ray scattering investigation of the solution structure of troponin C

International Nuclear Information System (INIS)

Hubbard, S.R.; Hodgson, K.O.; Doniach, S.

1988-01-01

X-ray crystallographic studies of troponin C have revealed a novel protein structure consisting of two globular domains, each containing two Ca 2+ -binding sites, connected via a nine-turn alpha-helix, three turns of which are fully exposed to solvent. Since the crystals were grown at pH approximately 5, it is of interest to determine whether this structure is applicable to the protein in solution under physiological conditions. We have used small-angle x-ray scattering to examine the solution structure of troponin C at pH 6.8 and the effect of Ca 2+ on the structure. The scattering data are consistent with an elongated structure in solution with a radius of gyration of approximately 23.0 A, which is quite comparable to that computed for the crystal structure. The experimental scattering profile and the scattering profile computed from the crystal structure coordinates do, however, exhibit differences at the 40-A level. A weak Ca 2+ -facilitated dimerization of troponin C was observed. The data rule out large Ca 2+ -induced structural changes, indicating rather that the molecule with Ca 2+ bound is only slightly more compact than the Ca 2+ -free molecule

X-ray data booklet. Revision

Energy Technology Data Exchange (ETDEWEB)

Vaughan, D. (ed.)

1986-04-01

A compilation of data is presented. Included are properties of the elements, electron binding energies, characteristic x-ray energies, fluorescence yields for K and L shells, Auger energies, energy levels for hydrogen-, helium-, and neonlike ions, scattering factors and mass absorption coefficients, and transmission bands of selected filters. Also included are selected reprints on scattering processes, x-ray sources, optics, x-ray detectors, and synchrotron radiation facilities. (WRF)

X-ray and neutron diffuse scattering in LiNbO3 from 38 to 1200 K

International Nuclear Information System (INIS)

Zotov, N.; Mayer, H.M.; Guethoff, F.; Hohlwein, D.

1995-01-01

A semi-quantitative description of X-ray and neutron diffuse scattering from congruent lithium niobate, LiNbO 3 , is given. The diffuse scattering is concentrated in three sets of diffuse planes perpendicular to the pseudo-cubic symmetry-related [221], [241] and [ anti 4 anti 21] directions and can be attributed to one-dimensional displacive and chemical disorder along these directions. The variation of the X-ray and neutron diffuse intensities with the scattering vector, as well as the comparison between X-ray and neutron data, indicate that more than one type of atom is involved. Temperature variations are followed from 38 to 1200 K. Different disorder models are discussed. The increase of the integrated intensities of the diffuse lines along the [0 1k 2l] * and [0 anti 1k 4l] * directions (i.e. sections of the diffuse planes) up to 800 K followed by a slight decrease at higher temperatures may be interpreted either by static disorder related to temperature-dependent variation of disorder/defect clusters or by dynamic disorder. Inelastic neutron scattering experiments do not show any anomaly of the transversal acoustic (TA) modes. (orig.)

Geant4 simulations of soft proton scattering in X-ray optics. A tentative validation using laboratory measurements

Science.gov (United States)

Fioretti, Valentina; Mineo, Teresa; Bulgarelli, Andrea; Dondero, Paolo; Ivanchenko, Vladimir; Lei, Fan; Lotti, Simone; Macculi, Claudio; Mantero, Alfonso

2017-12-01

Low energy protons (process responsible for the grazing angle scattering processes is mandatory to evaluate the impact of such events on the performance (e.g. observation time, sensitivity) of future X-ray telescopes as the ESA ATHENA mission. The Remizovich model describes particles reflected by solids at glancing angles in terms of the Boltzmann transport equation using the diffuse approximation and the model of continuous slowing down in energy. For the first time this solution, in the approximation of no energy losses, is implemented, verified, and qualitatively validated on top of the Geant4 release 10.2, with the possibility to add a constant energy loss to each interaction. This implementation is verified by comparing the simulated proton distribution to both the theoretical probability distribution and with independent ray-tracing simulations. Both the new scattering physics and the Coulomb scattering already built in the official Geant4 distribution are used to reproduce the latest experimental results on grazing angle proton scattering. At 250 keV multiple scattering delivers large proton angles and it is not consistent with the observation. Among the tested models, the single scattering seems to better reproduce the scattering efficiency at the three energies but energy loss obtained at small scattering angles is significantly lower than the experimental values. In general, the energy losses obtained in the experiment are higher than what obtained by the simulation. The experimental data are not completely representative of the soft proton scattering experienced by current X-ray telescopes because of the lack of measurements at low energies (distribution at the exit of X-ray optics.

Quantitative anomalous small-angle X-ray scattering - The determination of chemical concentrations in nano-scale phases

International Nuclear Information System (INIS)

Goerigk, G.; Huber, K.; Mattern, N.; Williamson, D.L.

2012-01-01

In the last years Anomalous Small-Angle X-ray Scattering became a precise quantitative method resolving scattering contributions two or three orders of magnitude smaller compared to the overall small-angle scattering, which are related to the so-called pure-resonant scattering contribution. Additionally to the structural information precise quantitative information about the different constituents of multi-component systems like the fraction of a chemical component implemented into the materials nano-structures are obtained from these scattering contributions. The application of the Gauss elimination algorithm to the vector equation established by ASAXS measurements at three X-ray energies is demonstrated for three examples from chemistry and solid state physics. All examples deal with the quantitative analysis of the Resonant Invariant (RI-analysis). From the integrals of the pure-resonant scattering contribution the chemical concentrations in nano-scaled phases are determined. In one example the correlated analysis of the Resonant Invariant and the Non-resonant Invariant (NI-analysis) is employed. (authors)

Design of a 4.8-m ring for inverse Compton scattering x-ray source

Directory of Open Access Journals (Sweden)

H. S. Xu

2014-07-01

Full Text Available In this paper we present the design of a 50 MeV compact electron storage ring with 4.8-meter circumference for the Tsinghua Thomson scattering x-ray source. The ring consists of four dipole magnets with properly adjusted bending radii and edge angles for both horizontal and vertical focusing, and a pair of quadrupole magnets used to adjust the horizontal damping partition number. We find that the dynamic aperture of compact storage rings depends essentially on the intrinsic nonlinearity of the dipole magnets with small bending radius. Hamiltonian dynamics is found to agree well with results from numerical particle tracking. We develop a self-consistent method to estimate the equilibrium beam parameters in the presence of the intrabeam scattering, synchrotron radiation damping, quantum excitation, and residual gas scattering. We also optimize the rf parameters for achieving a maximum x-ray flux.

Ultra-High Field Magnets for X-Ray and Neutron Scattering using High Temperature Superconductors

Energy Technology Data Exchange (ETDEWEB)

Winn, Barry L. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Broholm, C. [Johns Hopkins Univ., Baltimore, MD (United States); Bird, M. [Florida State Univ., Tallahassee, FL (United States). National High Magnetic Field Lab. (MagLab); Breneman, Bruce C. [General Atomics, San Diego, CA (United States); Coffey, Michael [Cryomagnetics, Oak Ridge, TN (United States); Cutler, Roy I. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Duckworth, Robert C. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Erwin, R. [National Inst. of Standards and Technology (NIST), Gaithersburg, MD (United States); Hahn, Seungyong [Florida State Univ., Tallahassee, FL (United States). National High Magnetic Field Lab. (MagLab); Hernandez, Yamali [National Inst. of Standards and Technology (NIST), Gaithersburg, MD (United States); Herwig, Kenneth W. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Holland, Leo D. [General Atomics, San Diego, CA (United States); Lonergan, Kevin M. [Oxford Instruments, Abingdon (United Kingdom); Melhem, Ziad [Oxford Instruments, Abingdon (United Kingdom); Minter, Stephen J. [Cryomagnetics, Oak Ridge, TN (United States); Nelson, C. [Brookhaven National Lab. (BNL), Upton, NY (United States); Paranthaman, M. Parans [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Pierce, Josh [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Ruff, Jacob [Cornell Univ., Ithaca, NY (United States); Shen, Tengming [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Sherline, Todd E. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Smeibidl, Peter G. [Helmholtz-Zentrum Berlin (HZB), (Germany); Tennant, David [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); van der Laan, Danko [Advanced Conductor Technologies, LLC, Boulder, CO (United States); Wahle, Robert J. [Helmholtz-Zentrum Berlin (HZB), (Germany); Zhang, Yifei [SuperPower, Inc., Schenectady, NY (United States)

2017-01-01

X-ray and neutron scattering techniques are capable of acquiring information about the structure and dynamics of quantum matter. However, the high-field magnet systems currently available at x-ray and neutron scattering facilities in the United States are limited to fields of 16 tesla (T) at maximum, which precludes applications that require and/or study ultra-high field states of matter. This gap in capability—and the need to address it—is a central conclusion of the 2005 National Academy of Sciences report by the Committee on Opportunities in High Magnetic Field Science. To address this gap, we propose a magnet development program that would more than double the field range accessible to scattering experiments. With the development and use of new ultra-high field–magnets, the program would bring into view new worlds of quantum matter with profound impacts on our understanding of advanced electronic materials.

Hard synchrotron radiation scattering from a nonideal surface grating from multilayer X-ray mirrors

International Nuclear Information System (INIS)

Punegov, V.I.; Nesterets, Ya.I.; Mytnichenko, S.V.; Kovalenko, N.V.; Chernov, V.A.

2003-01-01

The hard synchrotron radiation scattering from a multilayer surface grating is theoretically and experimentally investigated. The numerical calculations of angular distribution of scattering intensity from X-ray mirror Ni/C are executed with use of recurrence formulae and statistical dynamical theory of diffraction. It is shown, that the essential role in formation of a diffraction pattern plays a diffuse scattering caused by structure imperfection of a multilayer grating [ru

Measurement and Interpretation of Diffuse Scattering in X-Ray Diffraction for Macromolecular Crystallography

Energy Technology Data Exchange (ETDEWEB)

Wall, Michael E. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2017-10-16

X-ray diffraction from macromolecular crystals includes both sharply peaked Bragg reflections and diffuse intensity between the peaks. The information in Bragg scattering reflects the mean electron density in the unit cells of the crystal. The diffuse scattering arises from correlations in the variations of electron density that may occur from one unit cell to another, and therefore contains information about collective motions in proteins.

Microdefects revealed by X-ray diffusion scattering in Czochralski-growth dislocation-free silicon single crystals

International Nuclear Information System (INIS)

Bublik, B.T.; Zotov, N.M.

1997-01-01

Microdefects in the regions of Si crystals having different thermal history defined by growth conditions was studied by the X-ray diffuse scattering method on a triple crystal X-ray diffractometer. It was shown that in such crystals the microdefects with positive strength are prevalent. However, between the above indicated regions the defects with the strength of opposite sign prevail

Guest–Host Interactions Investigated by Time-Resolved X-ray Spectroscopies and Scattering at MHz Rates

DEFF Research Database (Denmark)

Haldrup, Martin Kristoffer; Vanko, G.; Gawelda, W.

2012-01-01

We have studied the photoinduced low spin (LS) to high spin (HS) conversion of [Fe(bipy)3]2+ in aqueous solution. In a laser pump/X-ray probe synchrotron setup permitting simultaneous, time-resolved X-ray diffuse scattering (XDS) and X-ray spectroscopic measurements at a 3.26 MHz repetition rate...... lifetime, allowing the detection of an ultrafast change in bulk solvent density. An analysis approach directly utilizing the spectroscopic data in the XDS analysis effectively reduces the number of free parameters, and both combined permit extraction of information about the ultrafast structural dynamics...

Quantitative spectromicroscopy from inelastically scattered photoelectrons in the hard X-ray range

Energy Technology Data Exchange (ETDEWEB)

Renault, O., E-mail: olivier.renault@cea.fr; Zborowski, C.; Risterucci, P. [Univ. Grenoble Alpes, F-38000 Grenoble, France and CEA, LETI, MINATEC Campus, F-38054 Grenoble (France); Wiemann, C.; Schneider, C. M. [Peter Grünberg Institute (PGI-6) and JARA-FIT, Research Center Jülich, D-52425 Jülich (Germany); Grenet, G. [Institut des Nanotechnologies de Lyon, Ecole Centrale, 69134 Ecully Cedex (France); Tougaard, S. [Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, DK-5230 Odense M (Denmark)

2016-07-04

We demonstrate quantitative, highly bulk-sensitive x-ray photoelectron emission microscopy by analysis of inelastically scattered photoelectrons in the hard X-ray range, enabling elemental depth distribution analysis in deeply buried layers. We show results on patterned structures used in electrical testing of high electron mobility power transistor devices with an epitaxial Al{sub 0.25}Ga{sub 0.75}N channel and a Ti/Al metal contact. From the image series taken over an energy range of up to 120 eV in the Ti 1s loss feature region and over a typical 100 μm field of view, one can accurately retrieve, using background analysis together with an optimized scattering cross-section, the Ti depth distribution from 14 nm up to 25 nm below the surface. The method paves the way to multi-elemental, bulk-sensitive 3D imaging and investigation of phenomena at deeply buried interfaces and microscopic scales by photoemission.

Management of diagnostic x-ray radiation in developing countries

International Nuclear Information System (INIS)

Date, T.

2000-01-01

The purpose of this study is to provide a simple, inexpensive, and effective method to prevent the scattering of x-ray radiation by using a lead apron in the x-ray rooms of developing countries. In developed countries, the scattering of x-ray radiation among patients and radiographers in diagnostic x-ray rooms has been minimized by various methods. However, in some developing countries, scattered x-ray radiation has not yet been adequately contained. The policy of As Law As Reasonably Achievable (ALARA) requires that patients who are waiting for their examinations must be protected from scattered x-ray radiation. However, from the author's experience, protection from scattered x-ray radiation in x-ray rooms is often insufficient in developing countries. In addition, major public hospitals in big cities are overwhelmed with patients because radiology resources in developing countries are concentrated in the big cities. Moreover, the situation is made worse by short working hours in public hospitals. Hours from 10 a.m. to 3 p.m. are typical. Because of the circumstances, radiographers, who are in a rush to finish all of the examinations within their normal working hours, sometimes allow patients to enter the x-ray rooms while they are waiting for their examinations. Chest and abdominal x-rays are the most common kinds of diagnostic x-ray examination in developing countries. Thus, in this study, anthropomorphic chest and abdominal phantoms were x-rayed for measuring the scattered x-ray radiation with and without protection using a 0.25mmPb lead apron at specific points from the anthropomorphic phantoms in the x-ray room. The lead apron was hung on a mobile apron-hanger and placed next to the anthropomorphic phantom. The scattered radiation dosimetry for chest x-rays proves that this simple method reduces scattered x-ray radiation to 15% at one-meter point and to almost 0% at the two-meter point from the anthropomorphic phantom in the x-ray room. Lead aprons are

Compact structure of ribosomal protein S4 in solution as revealed by small-angle X-ray scattering

International Nuclear Information System (INIS)

Serdyuk, I.N.; Sarkisyan, M.A.; Gogia, Z.V.

1981-01-01

The authors report the results of a small-angle X-ray scattering study of ribosomal protein preparations obtained by neutron scattering method. The theoretical resolution of the diffractometer (Kratky camera, the entrance slit 80 μm, the receiving slit 190 μm, the sample-detector distance 20.4 cm) was the same as the resolution of X-ray diffractometers, on which high rsub(g) values for ribosomal proteins were obtained. They used protein S4 adjusted to 20 mg/ml without any essential loss of solubility. The scattering indicatrix obtained in a wide range of angles has demonstrated that the X-ray rsub(g) obtained here coincides with the earlier obtained neutron rsub(g) and the outer part of the scattering curve is similar to that of slightly elongated compact bodies. They conclude that all discrepancies between their data on the study of ribosomal protein structure in solution and other data are not connected with the characteristics of the instruments used but only with the quality of the protein preparations. (Auth.)

Development of a methodology for low-energy X-ray absorption correction in biological samples using radiation scattering techniques

International Nuclear Information System (INIS)

Pereira, Marcelo O.; Anjos, Marcelino J.; Lopes, Ricardo T.

2009-01-01

Non-destructive techniques with X-ray, such as tomography, radiography and X-ray fluorescence are sensitive to the attenuation coefficient and have a large field of applications in medical as well as industrial area. In the case of X-ray fluorescence analysis the knowledge of photon X-ray attenuation coefficients provides important information to obtain the elemental concentration. On the other hand, the mass attenuation coefficient values are determined by transmission methods. So, the use of X-ray scattering can be considered as an alternative to transmission methods. This work proposes a new method for obtain the X-ray absorption curve through superposition peak Rayleigh and Compton scattering of the lines L a e L β of Tungsten (Tungsten L lines of an X-ray tube with W anode). The absorption curve was obtained using standard samples with effective atomic number in the range from 6 to 16. The method were applied in certified samples of bovine liver (NIST 1577B) , milk powder and V-10. The experimental measurements were obtained using the portable system EDXRF of the Nuclear Instrumentation Laboratory (LIN-COPPE/UFRJ) with Tungsten (W) anode. (author)

Analysis of Order Formation in Block Copolymer Thin Films UsingResonant Soft X-Ray Scattering

Energy Technology Data Exchange (ETDEWEB)

Virgili, Justin M.; Tao, Yuefei; Kortright, Jeffrey B.; Balsara,Nitash P.; Segalman, Rachel A.

2006-11-27

The lateral order of poly(styrene-block-isoprene) copolymer(PS-b-PI) thin films is characterized by the emerging technique ofresonant soft X-ray scattering (RSOXS) at the carbon K edge and comparedto ordering in bulk samples of the same materials measured usingconventional small-angle X-ray scattering. We show resonance using theoryand experiment that the loss of scattering intensity expected with adecrease in sample volume in the case of thin films can be overcome bytuning X-rays to the pi* resonance of PS or PI. Using RSOXS, we study themicrophase ordering of cylinder- and phere-forming PS-b-PI thin films andcompare these results to position space data obtained by atomic forcemicroscopy. Our ability to examine large sample areas (~;9000 mu m2) byRSOXS enables unambiguous identification of the lateral lattice structurein the thin films. In the case of the sphere-forming copolymer thin film,where the spheres are hexagonally arranged, the average sphere-to-spherespacing is between the bulk (body-centered cubic) nearest neighbor andbulk unit cell spacings. In the case of the cylinder-forming copolymerthin film, the cylinder-to-cylinder spacing is within experimental errorof that obtained in the bulk.

Alamethicin in lipid bilayers: combined use of X-ray scattering and MD simulations.

Science.gov (United States)

Pan, Jianjun; Tieleman, D Peter; Nagle, John F; Kucerka, Norbert; Tristram-Nagle, Stephanie

2009-06-01

We study fully hydrated bilayers of two di-monounsaturated phospholipids diC18:1PC (DOPC) and diC22:1PC with varying amounts of alamethicin (Alm). We combine the use of X-ray diffuse scattering and molecular dynamics simulations to determine the orientation of alamethicin in model lipids. Comparison of the experimental and simulated form factors shows that Alm helices are inserted transmembrane at high humidity and high concentrations, in agreement with earlier results. The X-ray scattering data and the MD simulations agree that membrane thickness changes very little up to 1/10 Alm/DOPC. In contrast, the X-ray data indicate that the thicker diC22:1PC membrane thins with added Alm, a total decrease in thickness of 4 A at 1/10 Alm/diC22:1PC. The different effect of Alm on the thickness changes of the two bilayers is consistent with Alm having a hydrophobic thickness close to the hydrophobic thickness of 27 A for DOPC; Alm is then mismatched with the 7 A thicker diC22:1PC bilayer. The X-ray data indicate that Alm decreases the bending modulus (K(C)) by a factor of approximately 2 in DOPC and a factor of approximately 10 in diC22:1PC membranes (P/L approximately 1/10). The van der Waals and fluctuational interactions between bilayers are also evaluated through determination of the anisotropic B compressibility modulus.

Diffuse x-ray scattering and transmission electron microscopy study of defects in antimony-implanted silicon

Science.gov (United States)

Takamura, Y.; Marshall, A. F.; Mehta, A.; Arthur, J.; Griffin, P. B.; Plummer, J. D.; Patel, J. R.

2004-04-01

Ion implantation followed by laser annealing has been used to create supersaturated and electrically active concentrations of antimony in silicon. Upon subsequent thermal annealing, however, these metastable dopants deactivate towards the equilibrium solubility limit. In this work, the formation of inactive antimony structures has been studied with grazing incidence diffuse x-ray scattering, and transmission electron microscopy, and the results are correlated to previous high-resolution x-ray diffraction data. We find that at a concentration of 6.0×1020 cm-3, small, incoherent clusters of radius 3-4 Å form during annealing at 900 °C. At a higher concentration of 2.2×1021 cm-3, deactivation at 600 °C occurs through the formation of small, antimony aggregates and antimony precipitates. The size of these precipitates from diffuse x-ray scattering is roughly 15 Å in radius for anneal times from 15 to 180 seconds. This value is consistent with the features observed in high-resolution and mass contrast transmission electron microscopy images. The coherent nature of the aggregates and precipitates causes the expansion of the surrounding silicon matrix as the deactivation progresses. In addition, the sensitivity of the diffuse x-ray scattering technique has allowed us to detect the presence of small clusters of radius ˜2 Å in unprocessed Czochralski silicon wafers. These defects are not observed in floating zone silicon wafers, and are tentatively attributed to thermal donors.

Combined Approach for the Structural Characterization of Alkali Fluoroscandates: Solid-State NMR, Powder X-ray Diffraction, and Density Functional Theory Calculations.

Science.gov (United States)

Rakhmatullin, Aydar; Polovov, Ilya B; Maltsev, Dmitry; Allix, Mathieu; Volkovich, Vladimir; Chukin, Andrey V; Boča, Miroslav; Bessada, Catherine

2018-02-05

The structures of several fluoroscandate compounds are presented here using a characterization approach combining powder X-ray diffraction and solid-state NMR. The structure of K 5 Sc 3 F 14 was fully determined from Rietveld refinement performed on powder X-ray diffraction data. Moreover, the local structures of NaScF 4 , Li 3 ScF 6 , KSc 2 F 7 , and Na 3 ScF 6 compounds were studied in detail from solid-state 19 F and 45 Sc NMR experiments. The 45 Sc chemical shift ranges for six- and seven-coordinated scandium environments were defined. The 19 F chemical shift ranges for bridging and terminal fluorine atoms were also determined. First-principles calculations of the 19 F and 45 Sc NMR parameters were carried out using plane-wave basis sets and periodic boundary conditions (CASTEP), and the results were compared with the experimental data. A good agreement between the calculated shielding constants and experimental chemical shifts was obtained. This demonstrates the good potential of computational methods in spectroscopic assignments of solid-state 45 Sc NMR spectroscopy.

Measurement of illite particle thickness using a direct Fourier transform of small-angle X-ray scattering data

Science.gov (United States)

Shang, Chao; Rice, James A.; Eberl, Dennis D.; Lin, Jar-Shyong

2003-01-01

It has been suggested that interstratified illite-smectite (I-S) minerals are composed of aggregates of fundamental particles. Many attempts have been made to measure the thickness of such fundamental particles, but each of the methods used suffers from its own limitations and uncertainties. Small-angle X-ray scattering (SAXS) can be used to measure the thickness of particles that scatter X-rays coherently. We used SAXS to study suspensions of Na-rectorite and other illites with varying proportions of smectite. The scattering intensity (I) was recorded as a function of the scattering vector, q = (4 /) sin(/2), where  is the X-ray wavelength and  is the scattering angle. The experimental data were treated with a direct Fourier transform to obtain the pair distance distribution function (PDDF) that was then used to determine the thickness of illite particles. The Guinier and Porod extrapolations were used to obtain the scattering intensity beyond the experimental q, and the effects of such extrapolations on the PDDF were examined. The thickness of independent rectorite particles (used as a reference mineral) is 18.3 Å. The SAXS results are compared with those obtained by X-ray diffraction peak broadening methods. It was found that the power-law exponent (α) obtained by fitting the data in the region of q = 0.1-0.6 nm-1 to the power law (I = I0q-α) is a linear function of illite particle thickness. Therefore, illite particle thickness could be predicted by the linear relationship as long as the thickness is within the limit where α <4.0.

Bone X-Ray (Radiography)

Medline Plus

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

Effects of electron scattering on the oscillations of an X-ray source

International Nuclear Information System (INIS)

Kylafis, N.D.; Klimis, G.S.

1987-01-01

The time variability observed at infinity due to a variable point source at the center of a spherical cloud of radius R and optical depth to electron scattering tau is analytically determined. The emissin pattern of the source and its time variability are assumed to be of the following three forms: (1) isotropic emission with intensity varying sinusoidally in time with angular frequency Omega(L), (2) emission in the form of a delta-function beam rotating with angular frequency Omega(R) about a fixed axis and with intensity constant in time, and (3) emission in the form of a delta-function beam rotating with angular frequency Omega(R) about a fixed axis and with intensity varying sinusoidally in time with angular frequency Omega(L). More complicated source emissions and variabilities are studied by superposing the above forms. The results of our calculations reveal the conditions under which quasi-periodic oscillations can be observed from X-ray sources, while periodic oscillations are completely smeared out. Furthermore, these results can be used to study the X-ray oscillations of such sources as Her X-1, Cyg X-3, and the Vela pulsar, which are believed to be embedded in scattering clouds. 35 references

Diffuse X-ray scattering near the Bragg reflection of P-doped Czochralski silicon

International Nuclear Information System (INIS)

Stojanoff, V.; Pimentel, C.A.F.

1983-01-01

Bragg line profile and high resolution diffuse X-ray scattering measurements around the (400) reciprocal lattice point of dislocation-free Czochralski Si single crystals P-doped have shown defects of interstitial nature with typical size about 1000 A. (Author) [pt

Resonant soft x-ray scattering and charge density waves in correlated systems

NARCIS (Netherlands)

Rusydi, Andrivo

2006-01-01

Summary This work describes results obtained on the study of charge density waves (CDW) in strongly correlated systems with a new experimental method: resonant soft x-ray scattering (RSXS). The basic motivation is the 1986 discovery by Bednorz and Müler of a new type of superconductor, based on Cu

Novel micro-reactor flow cell for investigation of model catalysts using in situ grazing-incidence X-ray scattering.

Science.gov (United States)

Kehres, Jan; Pedersen, Thomas; Masini, Federico; Andreasen, Jens Wenzel; Nielsen, Martin Meedom; Diaz, Ana; Nielsen, Jane Hvolbæk; Hansen, Ole; Chorkendorff, Ib

2016-03-01

The design, fabrication and performance of a novel and highly sensitive micro-reactor device for performing in situ grazing-incidence X-ray scattering experiments of model catalyst systems is presented. The design of the reaction chamber, etched in silicon on insulator (SIO), permits grazing-incidence small-angle X-ray scattering (GISAXS) in transmission through 10 µm-thick entrance and exit windows by using micro-focused beams. An additional thinning of the Pyrex glass reactor lid allows simultaneous acquisition of the grazing-incidence wide-angle X-ray scattering (GIWAXS). In situ experiments at synchrotron facilities are performed utilizing the micro-reactor and a designed transportable gas feed and analysis system. The feasibility of simultaneous in situ GISAXS/GIWAXS experiments in the novel micro-reactor flow cell was confirmed with CO oxidation over mass-selected Ru nanoparticles.

Neutron and x-ray scattering studies of premartensitic phenomena

International Nuclear Information System (INIS)

Shapiro, S.M.

1987-01-01

This paper discusses neutron and x-ray investigations of some metallic alloys which are known to exhibit martensitic transformations. It is shown that precursor effects are usually present in the diffuse scattering and in the phonon dispersion curves, but the transition cannot be described in terms of the soft mode picture used in the Landau and Devonshire theory to describe structural phase transitions. In addition, it is noted that it is inappropriate to look at these microstructures as incommensurate systems, but more correctly as a coherent coexistence of two phases

Testing ion structure models with x-ray Thomson scattering

Directory of Open Access Journals (Sweden)

Wünsch K.

2013-11-01

Full Text Available We investigate the influence of various ionic structure models on the interpretation of the X-ray Thomson scattering signal. For the calculation of the ion structure, classical hypernetted chain equations are used applying different effective inter-particle potentials. It is shown that the different models lead to significant discrepancies in the theoretically predicted weight of the Rayleigh peak, in particular for small k-values where correlation effects are important. Here, we propose conditions which might allow for an experimental verification of the theories under consideration of experimental constraints of k-vector blurring.

An upgrade beamline for combined wide, small and ultra small-angle x-ray scattering at the ESRF

Energy Technology Data Exchange (ETDEWEB)

Van Vaerenbergh, Pierre; Léonardon, Joachim; Sztucki, Michael; Boesecke, Peter; Gorini, Jacques; Claustre, Laurent; Sever, Franc; Morse, John; Narayanan, Theyencheri [ESRF - The European Synchrotron, F-38043 Grenoble (France)

2016-07-27

This contribution presents the main design features of the upgraded beamline ID02 (TRUSAXS). The beamline combines different small-angle X-ray scattering techniques in one unique instrument. The key component of this instrument is an evacuated (5×10{sup −3} mbar) stainless steel detector tube of length 34 m and diameter 2 m. Three different detectors (Rayonix MX170, Pilatus 300 K and FReLoN 4M) are housed inside a motorized wagon which travels along a rail system with very low parasitic lateral movements (± 0.3 mm). This system allows automatically changing the sample-to-detector distance from about 1 m to 31 m and selecting the desired detector. In addition, a wide angle detector (Rayonix LX170) is installed just above the entrance cone of the tube for optional wide-angle X-ray scattering measurements. The beamstop system enables monitoring of the X-ray beam intensity in addition to blocking the primary beam, and automated insertion of selected masks behind the primary beamstop. The focusing optics and collimation system permit to cover a scattering vector (q) range of 0.002 nm{sup −1} ≤ q ≤ 50 nm{sup −1} with one unique setting using 0.1 nm X-ray wavelength for moderate flux (5×10{sup 12} photons/sec). However, for higher flux (6x10{sup 13} photons/sec) or higher resolution (minimum q < 0.001 nm{sup −1}), focusing and collimation, respectively need to be varied. For a sample-to-detector distance of 31 m and 0.1 nm wavelength, two dimensional ultra small-angle X-ray scattering patterns can be recorded down to q≈0.001 nm{sup −1} with far superior quality as compared to one dimensional profiles obtained with a Bonse-Hart instrument.

Real-time x-ray scattering study of the initial growth of organic crystals on polymer brushes

Energy Technology Data Exchange (ETDEWEB)

An, Sung Yup; Ahn, Kwangseok; Kim, Doris Yangsoo; Lee, Dong Ryeol, E-mail: drlee@ssu.ac.kr [Department of Physics, Soongsil University, Seoul 156-743 (Korea, Republic of); Lee, Hyun-Hwi [Pohang Accelerator Laboratory, Pohang University of Science and Technology, Pohang 790-784 (Korea, Republic of); Cho, Jeong Ho, E-mail: jhcho94@skku.edu [Department of Chemical Engineering, SKKU Advanced Institute of Nanotechnology (SAINT) and Center for Human Interface Nano Technology (HINT), Sungkyunkwan University, Suwon 440-476 (Korea, Republic of)

2014-04-21

We studied the early-stage growth structures of pentacene organic crystals grown on polymer brushes using real-time x-ray scattering techniques. In situ x-ray reflectivity and atomic force microscopy analyses revealed that at temperatures close to the glass transition temperature of polymer brush, the pentacene overlayer on a polymer brush film showed incomplete condensation and 3D island structures from the first monolayer. A growth model based on these observations was used to quantitatively analyze the real-time anti-Bragg x-ray scattering intensities measured during pentacene growth to obtain the time-dependent layer coverage of the individual pentacene monolayers. The extracted total coverage confirmed significant desorption and incomplete condensation in the pentacene films deposited on the polymer brushes. These effects are ascribed to the change in the surface viscoelasticity of the polymer brushes around the glass transition temperature.

Theoretical concepts of X-ray nanoscale analysis theory and applications

CERN Document Server

Benediktovitch, Andrei; Ulyanenkov, Alexander

2013-01-01

This book provides a concise survey of modern theoretical concepts of X-ray materials analysis. The principle features of the book are: basics of X-ray scattering, interaction between X-rays and matter and new theoretical concepts of X-ray scattering. The various X-ray techniques are considered in detail: high-resolution X-ray diffraction, X-ray reflectivity, grazing-incidence small-angle X-ray scattering and X-ray residual stress analysis. All the theoretical methods presented use the unified physical approach. This makes the book especially useful for readers learning and performing data ana

Application of focused-beam flat-sample method to synchrotron powder X-ray diffraction with anomalous scattering effect

International Nuclear Information System (INIS)

Tanaka, M; Katsuya, Y; Matsushita, Y

2013-01-01

The focused-beam flat-sample method (FFM), which is a method for high-resolution and rapid synchrotron X-ray powder diffraction measurements by combination of beam focusing optics, a flat shape sample and an area detector, was applied for diffraction experiments with anomalous scattering effect. The advantages of FFM for anomalous diffraction were absorption correction without approximation, rapid data collection by an area detector and good signal-to-noise ratio data by focusing optics. In the X-ray diffraction experiments of CoFe 2 O 4 and Fe 3 O 4 (By FFM) using X-rays near the Fe K absorption edge, the anomalous scattering effect between Fe/Co or Fe 2+ /Fe 3+ can be clearly detected, due to the change of diffraction intensity. The change of observed diffraction intensity as the incident X-ray energy was consistent with the calculation. The FFM is expected to be a method for anomalous powder diffraction.

Measurements of accurate x-ray scattering data of protein solutions using small stationary sample cells

Science.gov (United States)

Hong, Xinguo; Hao, Quan

2009-01-01

In this paper, we report a method of precise in situ x-ray scattering measurements on protein solutions using small stationary sample cells. Although reduction in the radiation damage induced by intense synchrotron radiation sources is indispensable for the correct interpretation of scattering data, there is still a lack of effective methods to overcome radiation-induced aggregation and extract scattering profiles free from chemical or structural damage. It is found that radiation-induced aggregation mainly begins on the surface of the sample cell and grows along the beam path; the diameter of the damaged region is comparable to the x-ray beam size. Radiation-induced aggregation can be effectively avoided by using a two-dimensional scan (2D mode), with an interval as small as 1.5 times the beam size, at low temperature (e.g., 4 °C). A radiation sensitive protein, bovine hemoglobin, was used to test the method. A standard deviation of less than 5% in the small angle region was observed from a series of nine spectra recorded in 2D mode, in contrast to the intensity variation seen using the conventional stationary technique, which can exceed 100%. Wide-angle x-ray scattering data were collected at a standard macromolecular diffraction station using the same data collection protocol and showed a good signal/noise ratio (better than the reported data on the same protein using a flow cell). The results indicate that this method is an effective approach for obtaining precise measurements of protein solution scattering.

Measurements of accurate x-ray scattering data of protein solutions using small stationary sample cells

International Nuclear Information System (INIS)

Hong Xinguo; Hao Quan

2009-01-01

In this paper, we report a method of precise in situ x-ray scattering measurements on protein solutions using small stationary sample cells. Although reduction in the radiation damage induced by intense synchrotron radiation sources is indispensable for the correct interpretation of scattering data, there is still a lack of effective methods to overcome radiation-induced aggregation and extract scattering profiles free from chemical or structural damage. It is found that radiation-induced aggregation mainly begins on the surface of the sample cell and grows along the beam path; the diameter of the damaged region is comparable to the x-ray beam size. Radiation-induced aggregation can be effectively avoided by using a two-dimensional scan (2D mode), with an interval as small as 1.5 times the beam size, at low temperature (e.g., 4 deg. C). A radiation sensitive protein, bovine hemoglobin, was used to test the method. A standard deviation of less than 5% in the small angle region was observed from a series of nine spectra recorded in 2D mode, in contrast to the intensity variation seen using the conventional stationary technique, which can exceed 100%. Wide-angle x-ray scattering data were collected at a standard macromolecular diffraction station using the same data collection protocol and showed a good signal/noise ratio (better than the reported data on the same protein using a flow cell). The results indicate that this method is an effective approach for obtaining precise measurements of protein solution scattering.

Modern X-ray difraction. X-ray diffractometry for material scientists, physicists, and chemicists

International Nuclear Information System (INIS)

Spiess, L.; Schwarzer, R.; Behnken, H.; Teichert, G.

2005-01-01

The book yields a comprehensive survey over the applications of X-ray diffraction in fields like material techniques, metallurgy, electrotechniques, machine engineering, as well as micro- and nanotechniques. The necessary fundamental knowledge on X-ray diffraction are mediated foundedly and illustratively. Thereby new techniques and evaluation procedures are presented as well as well known methods. The content: Production and properties of X radiation, diffraction of X radiation, hardware for X-ray diffraction, methods of X-ray diffraction, lattice-constant determination, phase analysis, X-ray profile analysis, crystal structure analysis, X-ray radiographic stress analysis, X-ray radiographic texture analysis, crystal orientation determination, pecularities at thin films, small angle scattering

On the calculation of x-ray scattering signals from pairwise radial distribution functions

DEFF Research Database (Denmark)

Dohn, Asmus Ougaard; Biasin, Elisa; Haldrup, Kristoffer

2015-01-01

We derive a formulation for evaluating (time-resolved) x-ray scattering signals of solvated chemical systems, based on pairwise radial distribution functions, with the aim of this formulation to accompany molecular dynamics simulations. The derivation is described in detail to eliminate any possi...

X-ray small-angle scattering of polytetrahydrofuran solution, 3

International Nuclear Information System (INIS)

Izumi, Yoshinobu; Fuji, Masayuki; Shinbo, Kazuyuki; Miyake, Yasuhiro

1975-01-01

In a previous report, the conformation of polytetrahydrofuran (PTHF) in isopropyl alcohol as a theta solvent and in n-butyl alcohol as an intermediate solvent was examined by the small angle scattering of X-ray. As the result, the experimental scattering curve at theta temperature was explained well with the calculated curve obtained by superposing, while it was impossible to apply the similar method to the analysis of the scattering curve in the intermediate solvent. Recently, as the results of the calculation by Koyama on the angular distribution of light intensity scattered by stiff chain polymers and of the studies by Edwards and de Gennes on the asymptotic behavior of scattering curves in good solvents, the direct comparison of experimental and calculated scattering curves became possible. In this report, the comparison of the scattering curves of PTHF-alcohol systems is described. The systems employed were PTHF-n-propyl alcohol, PTHF-isobutyl alcohol, PTHF-sec-butyl alcohol, and PTHF-tert-butyl alcohol in addition to the previous two systems. The Guinier plots of the cross section factors of the PTHF-alcohol systems showed that the Guinier approximation on cross sections was not satisfied in cases of PTHF-isobutyl alcohol and PTHF-sec-butyl alcohol. The light scattering data at 44.6 0 C, the theta temperature of PTHF-isopropyl alcohol, are given. From the figures comparing experimental and calculated scattering curves, it was shown that there was appreciable solvent effect on the scattering curves of PTHF-alcohol systems. The relation predicted by Edwards and de Gennes was satisfied well in case of the systems in good solvents. (Kako, I.)

NATURAL CYCLOPENTANOID CYANOHYDRIN GLYCOSIDES .13. STRUCTURE DETERMINATION OF NATURAL EPOXYCYCLOPENTANES BY X-RAY CRYSTALLOGRAPHY AND NMR-SPECTROSCOPY

DEFF Research Database (Denmark)

Olafsdottir, E. S.; Sorensen, A. M.; Cornett, Claus

1991-01-01

nonannellated cyclopentane derivatives. The new glucosides were shown, by NMR spectroscopy (including NOE measurements), X-ray crystallography, and enzymatic hydrolysis to the corresponding cyanohydrins, to be (1R,2R,3R,4R)- and (1S,2S,3S,4S)-1-(beta-D-glucopyranosyloxy)-2,3-epoxy-4-hydroxycyclopenta ne-1...

Nonspherical atomic ground-state densities and chemical deformation densities from x-ray scattering

International Nuclear Information System (INIS)

Ruedenberg, K.; Schwarz, W.H.E.

1990-01-01

Presuming that chemical insight can be gained from the difference between the molecular electron density and the superposition of the ground-state densities of the atoms in a molecule, it is pointed out that, for atoms with degenerate ground states, an unpromoted ''atom in a molecule'' is represented by a specific ensemble of the degenerate atomic ground-state wave functions and that this ensemble is determined by the anisotropic local surroundings. The resulting atomic density contributions are termed oriented ground state densities, and the corresponding density difference is called the chemical deformation density. The constraints implied by this conceptual approach for the atomic density contributions are formulated and a method is developed for determining them from x-ray scattering data. The electron density of the appropriate promolecule and its x-ray scattering are derived, the determination of the parameters of the promolecule is outlined, and the chemical deformation density is formulated

Structure of liposome encapsulating proteins characterized by X-ray scattering and shell-modeling

International Nuclear Information System (INIS)

Hirai, Mitsuhiro; Kimura, Ryota; Takeuchi, Kazuki; Hagiwara, Yoshihiko; Kawai-Hirai, Rika; Ohta, Noboru; Igarashi, Noriyuki; Shimuzu, Nobutaka

2013-01-01

Wide-angle X-ray scattering data using a third-generation synchrotron radiation source are presented. Lipid liposomes are promising drug delivery systems because they have superior curative effects owing to their high adaptability to a living body. Lipid liposomes encapsulating proteins were constructed and the structures examined using synchrotron radiation small- and wide-angle X-ray scattering (SR-SWAXS). The liposomes were prepared by a sequential combination of natural swelling, ultrasonic dispersion, freeze-throw, extrusion and spin-filtration. The liposomes were composed of acidic glycosphingolipid (ganglioside), cholesterol and phospholipids. By using shell-modeling methods, the asymmetric bilayer structure of the liposome and the encapsulation efficiency of proteins were determined. As well as other analytical techniques, SR-SWAXS and shell-modeling methods are shown to be a powerful tool for characterizing in situ structures of lipid liposomes as an important candidate of drug delivery systems

Building a Unified Computational Model for the Resonant X-Ray Scattering of Strongly Correlated Materials

Energy Technology Data Exchange (ETDEWEB)

Bansil, Arun [Northeastern Univ., Boston, MA (United States)

2016-12-01

Basic-Energy Sciences of the Department of Energy (BES/DOE) has made large investments in x-ray sources in the U.S. (NSLS-II, LCLS, NGLS, ALS, APS) as powerful enabling tools for opening up unprecedented new opportunities for exploring properties of matter at various length and time scales. The coming online of the pulsed photon source literally allows us to see and follow the dynamics of processes in materials at their natural timescales. There is an urgent need therefore to develop theoretical methodologies and computational models for understanding how x-rays interact with matter and the related spectroscopies of materials. The present project addressed aspects of this grand challenge of X-ray science. In particular, our Collaborative Research Team (CRT) focused on understanding and modeling of elastic and inelastic resonant X-ray scattering processes. We worked to unify the three different computational approaches currently used for modeling X-ray scattering—density functional theory, dynamical mean-field theory, and small-cluster exact diagonalization—to achieve a more realistic material-specific picture of the interaction between X-rays and complex matter. To achieve a convergence in the interpretation and to maximize complementary aspects of different theoretical methods, we concentrated on the cuprates, where most experiments have been performed. Our team included both US and international researchers, and it fostered new collaborations between researchers currently working with different approaches. In addition, we developed close relationships with experimental groups working in the area at various synchrotron facilities in the US. Our CRT thus helped toward enabling the US to assume a leadership role in the theoretical development of the field, and to create a global network and community of scholars dedicated to X-ray scattering research.

Physical characteristics of chemically modified starch from potatoes, evaluated by X-ray diffraction, SEM and NMR

International Nuclear Information System (INIS)

Sivolil; Perez, E.

1995-01-01

The aim of this study was to compare the physical characteristics of chemically modified starch by cross-linking and methylation in order to observe the changes occurred in the molecule which could give it a positive and specific application. The physical characteristics were evaluated by morphometric analysis using analytical methods as scanning electron microscopy, x-ray diffraction and nuclear magnetic resonance in solid state. The results point for all the evaluated characteristics that the cross-linked starch from potato maintains a granular size and shape similar to native starch, through some granules were affected since they presented cracks and outlet of internal material; the introduction of phosphate groups in the molecule is evident in the NMR spectra: the methylated starch from potato changed in a drastic way the structure of granules since the size increased from 9 to 53 μm of the native starch to 44 to 181 μm for the methylated, the X-ray spectra shows a formation of crystals, banishing the characteristic standard type B, likewise with NMR a modification of starch was observed due to the presence of methyl groups. (Author)

Structural characterization of oxidized allotaxially grown CoSi2 layers by x-ray scattering

International Nuclear Information System (INIS)

Kaendler, I. D.; Seeck, O. H.; Schlomka, J.-P.; Tolan, M.; Press, W.; Stettner, J.; Kappius, L.; Dieker, C.; Mantl, S.

2000-01-01

A series of buried CoSi 2 layers prepared by a modified molecular beam epitaxy process (allotaxy) and a subsequent wet-oxidation process was investigated by x-ray scattering. The oxidation time which determines the depth in which the CoSi 2 layers are located within the Si substrates has been varied during the preparation. The electron density profiles and the structure of the interfaces were extracted from specular reflectivity and diffuse scattering measurements. Crystal truncation rod investigations yielded the structure on an atomic level (crystalline quality). It turns out that the roughness of the CoSi 2 layers increases drastically with increasing oxidation time, i.e., with increasing depth of the buried layers. Furthermore, the x-ray data reveal that the oxidation growth process is diffusion limited. (c) 2000 American Institute of Physics

Center for X-Ray Optics, 1992

International Nuclear Information System (INIS)

1993-08-01

This report discusses the following topics: Center for X-Ray Optics; Soft X-Ray Imaging wit Zone Plate Lenses; Biological X-Ray microscopy; Extreme Ultraviolet Lithography for Nanoelectronic Pattern Transfer; Multilayer Reflective Optics; EUV/Soft X-ray Reflectometer; Photoemission Microscopy with Reflective Optics; Spectroscopy with Soft X-Rays; Hard X-Ray Microprobe; Coronary Angiography; and Atomic Scattering Factors

Water structure as a function of temperature from X-ray scattering experiments and ab initio molecular dynamics

International Nuclear Information System (INIS)

Hura, Greg; Russo, Daniela; Glaeser, Robert M.; Head-Gordon, Teresa; Krack, Matthias; Parrinello, Michele

2003-01-01

We present high-quality X-ray scattering experiments on pure water taken over a temperature range of 2 to 77 C using a synchrotron beam line at the advanced light source (ALS) at Lawrence Berkeley National Laboratory. The ALS X-ray scattering intensities are qualitatively different in trend of maximum intensity over this temperature range compared to older X-ray experiments. While the common procedure is to report both the intensity curve and radial distribution function(s), the proper extraction of the real-space pair correlation functions from the experimental scattering is very difficult due to uncertainty introduced in the experimental corrections, the proper weighting of OO, OH, and HH contributions, and numerical problems of Fourier transforming truncated data in Q-space. Instead, we consider the direct calculation of X-ray scattering spectra using electron densities derived from density functional theory based on real-space configurations generated with classical water models. The simulation of the experimental intensity is therefore definitive for determining radial distribution functions over a smaller Q-range. We find that the TIP4P, TIP5P and polarizable TIP4P-Pol2 water models, with DFT-LDA densities, show very good agreement with the experimental intensities, and TIP4P-Pol2 in particular shows quantitative agreement over the full temperature range. The resulting radial distribution functions from TIP4P-Pol2 provide the current best benchmarks for real-space water structure over the biologically relevant temperature range studied here

X-ray holography: X-ray interactions and their effects

International Nuclear Information System (INIS)

London, R.A.; Trebes, J.E.; Rosen, M.D.

1988-01-01

The authors summarize a theoretical study of the interactions of x-rays with a biological sample during the creation of a hologram. The choice of an optimal wavelength for x-ray holography is discussed, based on a description of scattering by objects within an aqueous environment. The problem of the motion resulting from the absorption of x-rays during a short exposure is described. The possibility of using very short exposures in order to capture the image before motion can compromise the resolution is explored. The impact of these calculation on the question of the feasibility of using an x-ray laser for holography of biological structures is discussed. 12 refs., 2 figs

Electrochemically adsorbed Pb on Ag (111) studied with grazing- incidence x-ray scattering

International Nuclear Information System (INIS)

Kortright, J.B.; Ross, P.N.; Melroy, O.R.; Toney, M.F.; Borges, G.L.; Samant, M.G.

1989-04-01

Grazing-incidence x-ray scattering studies of the evolution of electrochemically deposited layers of lead on silver (111) as a function of applied electrochemical potential are presented. Measurements were made with the adsorbed layers in contact with solution in a specially designed sample cell. The observed lead structures are a function of the applied potential and range from an incommensurate monolayer, resulting from underpotential deposition, to randomly oriented polycrystalline bulk lead, resulting from lower deposition potentials. These early experiments demonstrate the ability of in situ x-ray diffraction measurements to determine structures associated with electrochemical deposition. 6 refs., 4 figs

The modular small-angle X-ray scattering data correction sequence.

Science.gov (United States)

Pauw, B R; Smith, A J; Snow, T; Terrill, N J; Thünemann, A F

2017-12-01

Data correction is probably the least favourite activity amongst users experimenting with small-angle X-ray scattering: if it is not done sufficiently well, this may become evident only during the data analysis stage, necessitating the repetition of the data corrections from scratch. A recommended comprehensive sequence of elementary data correction steps is presented here to alleviate the difficulties associated with data correction, both in the laboratory and at the synchrotron. When applied in the proposed order to the raw signals, the resulting absolute scattering cross section will provide a high degree of accuracy for a very wide range of samples, with its values accompanied by uncertainty estimates. The method can be applied without modification to any pinhole-collimated instruments with photon-counting direct-detection area detectors.

Fractal morphology in lignite coal: a small angle x-ray scattering investigation

International Nuclear Information System (INIS)

Chitra, R.; Sen, D.; Mazumder, S.; Chandrasekaran, K.S.

1999-01-01

Small angle x-ray scattering technique has been used to study the pore morphology in lignite coal from Neyveli lignite mine (Tamilnadu, India). The sample were collected from three different locations of the same mine. SAXS profiles from all the three samples show almost identical functionality, irrespective of the locations from where the samples were collected. SAXS experiment using two different wavelengths also exhibit same functionality indicating the absence of multiple scattering. The analysis indicates the surface fractal nature of the pore morphology. The surface fractal dimension is calculated to be 2.58. (author)

Performance of a micro-strip gas chamber in solution X-ray scattering

CERN Document Server

Toyokawa, H; Inoko, Y; Nagayoshi, T; Nishi, Y; Nishikawa, Y; Ochi, A; Suzuki, M; Tanimori, T

2001-01-01

The performance of a Micro-Strip Gas Chamber in solution X-ray scattering was studied at the RIKEN structural biology beamline I of the SPring-8 facility. The practical dynamic range was confirmed to be approx 1,000,000 : 1 by measuring S sup - sup 4 decay from a polystyrene latex solution. Steep troughs of scattering profile from an apoferritin solution were clearly obtained without smearing. An unfolding process of a pH jump of cytochrome c was measured. A time resolution of 500 mu s was achieved.

Use of x-ray scattering in absorption corrections for x-ray fluorescence analysis of aerosol loaded filters

International Nuclear Information System (INIS)

Nielson, K.K.; Garcia, S.R.

1976-09-01

Two methods are described for computing multielement x-ray absorption corrections for aerosol samples collected in IPC-1478 and Whatman 41 filters. The first relies on scatter peak intensities and scattering cross sections to estimate the mass of light elements (Z less than 14) in the sample. This mass is used with the measured heavy element (Z greater than or equal to 14) masses to iteratively compute sample absorption corrections. The second method utilizes a linear function of ln(μ) vs ln(E) determined from the scatter peak ratios and estimates sample mass from the scatter peak intensities. Both methods assume a homogeneous depth distribution of aerosol in a fraction of the front of the filters, and the assumption is evaluated with respect to an exponential aerosol depth distribution. Penetration depths for various real, synthethic and liquid aerosols were measured. Aerosol penetration appeared constant over a 1.1 mg/cm 2 range of sample loading for IPC filters, while absorption corrections for Si and S varied by a factor of two over the same loading range. Corrections computed by the two methods were compared with measured absorption corrections and with atomic absorption analyses of the same samples

Experimental characterization of an ultrafast Thomson scattering x-ray source with three-dimensional time and frequency-domain analysis

Directory of Open Access Journals (Sweden)

W. J. Brown

2004-06-01

Full Text Available We present a detailed comparison of the measured characteristics of Thomson backscattered x rays produced at the Picosecond Laser-Electron Interaction for the Dynamic Evaluation of Structures facility at Lawrence Livermore National Laboratory to predicted results from a newly developed, fully three-dimensional time and frequency-domain code. Based on the relativistic differential cross section, this code has the capability to calculate time and space dependent spectra of the x-ray photons produced from linear Thomson scattering for both bandwidth-limited and chirped incident laser pulses. Spectral broadening of the scattered x-ray pulse resulting from the incident laser bandwidth, perpendicular wave vector components in the laser focus, and the transverse and longitudinal phase spaces of the electron beam are included. Electron beam energy, energy spread, and transverse phase space measurements of the electron beam at the interaction point are presented, and the corresponding predicted x-ray characteristics are determined. In addition, time-integrated measurements of the x rays produced from the interaction are presented and shown to agree well with the simulations.

Background radiation in inelastic X-ray scattering and X-ray emission spectroscopy. A study for Johann-type spectrometers

Science.gov (United States)

Paredes Mellone, O. A.; Bianco, L. M.; Ceppi, S. A.; Goncalves Honnicke, M.; Stutz, G. E.

2018-06-01

A study of the background radiation in inelastic X-ray scattering (IXS) and X-ray emission spectroscopy (XES) based on an analytical model is presented. The calculation model considers spurious radiation originated from elastic and inelastic scattering processes along the beam paths of a Johann-type spectrometer. The dependence of the background radiation intensity on the medium of the beam paths (air and helium), analysed energy and radius of the Rowland circle was studied. The present study shows that both for IXS and XES experiments the background radiation is dominated by spurious radiation owing to scattering processes along the sample-analyser beam path. For IXS experiments the spectral distribution of the main component of the background radiation shows a weak linear dependence on the energy for the most cases. In the case of XES, a strong non-linear behaviour of the background radiation intensity was predicted for energy analysis very close to the backdiffraction condition, with a rapid increase in intensity as the analyser Bragg angle approaches π / 2. The contribution of the analyser-detector beam path is significantly weaker and resembles the spectral distribution of the measured spectra. Present results show that for usual experimental conditions no appreciable structures are introduced by the background radiation into the measured spectra, both in IXS and XES experiments. The usefulness of properly calculating the background profile is demonstrated in a background subtraction procedure for a real experimental situation. The calculation model was able to simulate with high accuracy the energy dependence of the background radiation intensity measured in a particular XES experiment with air beam paths.

Bone X-Ray (Radiography)

Medline Plus

Full Text Available ... current x-ray images for diagnosis and disease management. top of page How is the procedure performed? ... have very controlled x-ray beams and dose control methods to minimize stray (scatter) radiation. This ensures ...

X-ray crystallography

Science.gov (United States)

2001-01-01

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

The complex ion structure of warm dense carbon measured by spectrally resolved x-ray scattering

Energy Technology Data Exchange (ETDEWEB)

Kraus, D.; Barbrel, B.; Falcone, R. W. [Department of Physics, University of California, Berkeley, California 94720 (United States); Vorberger, J. [Max-Planck-Institut für Physik komplexer Systeme, Nöthnitzer Straße 38, 01187 Dresden (Germany); Helfrich, J.; Frydrych, S.; Ortner, A.; Otten, A.; Roth, F.; Schaumann, G.; Schumacher, D.; Siegenthaler, K.; Wagner, F.; Roth, M. [Institut für Kernphysik, Technische Universität Darmstadt, Schlossgartenstraße 9, 64289 Darmstadt (Germany); Gericke, D. O.; Wünsch, K. [Centre for Fusion, Space and Astrophysics, Department of Physics, University of Warwick, Coventry CV4 7AL (United Kingdom); Bachmann, B.; Döppner, T. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Bagnoud, V.; Blažević, A. [GSI Helmholtzzentrum für Schwerionenforschung GmbH, Planckstraße 1, 64291 Darmstadt (Germany); and others

2015-05-15

We present measurements of the complex ion structure of warm dense carbon close to the melting line at pressures around 100 GPa. High-pressure samples were created by laser-driven shock compression of graphite and probed by intense laser-generated x-ray sources with photon energies of 4.75 keV and 4.95 keV. High-efficiency crystal spectrometers allow for spectrally resolving the scattered radiation. Comparing the ratio of elastically and inelastically scattered radiation, we find evidence for a complex bonded liquid that is predicted by ab-initio quantum simulations showing the influence of chemical bonds under these conditions. Using graphite samples of different initial densities we demonstrate the capability of spectrally resolved x-ray scattering to monitor the carbon solid-liquid transition at relatively constant pressure of 150 GPa. Showing first single-pulse scattering spectra from cold graphite of unprecedented quality recorded at the Linac Coherent Light Source, we demonstrate the outstanding possibilities for future high-precision measurements at 4th Generation Light Sources.

THE X-RAY HALO OF CEN X-3

International Nuclear Information System (INIS)

Thompson, Thomas W. J.; Rothschild, Richard E.

2009-01-01

Using two Chandra observations, we have derived estimates of the dust distribution and distance to the eclipsing high-mass X-ray binary Cen X-3 using the energy-resolved dust-scattered X-ray halo. By comparing the observed X-ray halos in 200 eV bands from 2-5 keV to the halo profiles predicted by the Weingartner and Draine interstellar grain model, we find that the vast majority (∼ 70%) of the dust along the line of sight to the system is located within about 300 pc of the Sun, although the halo measurements are insensitive to dust very close to the source. One of the Chandra observations occurred during an egress from eclipse as the pulsar emerged from behind the mass-donating primary. By comparing model halo light curves during this transition to the halo measurements, a source distance of 5.7 ± 1.5 kpc (68% confidence level) is estimated, although we find this result depends on the distribution of dust on very small scales. Nevertheless, this value is marginally inconsistent with the commonly accepted distance to Cen X-3 of 8 kpc. We also find that the energy scaling of the scattering optical depth predicted by the Weingartner and Draine interstellar grain model does not accurately represent the results determined by X-ray halo studies of Cen X-3. Relative to the model, there appears to be less scattering at low energies or more scattering at high energies in Cen X-3.

A Monte Carlo simulation of scattering reduction in spectral x-ray computed tomography

DEFF Research Database (Denmark)

Busi, Matteo; Olsen, Ulrik Lund; Bergbäck Knudsen, Erik

2017-01-01

In X-ray computed tomography (CT), scattered radiation plays an important role in the accurate reconstruction of the inspected object, leading to a loss of contrast between the different materials in the reconstruction volume and cupping artifacts in the images. We present a Monte Carlo simulation...

Low-angle X-ray scattering properties of irradiated spices

International Nuclear Information System (INIS)

Almeida, A.P.G.; Braz, D.; Barroso, R.C.; Lopes, R.T.

2007-01-01

The scattering of X-rays at low angles (LAXS) is a technique dominated by the coherent scattering process. One characteristic observation of low-angle coherent scattering is the so-called molecular interference effect, being characterized by the presence of one or more peaks in the forward direction of scattering. In the present study, LAXS profiles from five different spices are carefully measured in order to establish characteristic scattering signatures. Samples of Ceylon cinnamon, cumin, nutmeg, paprika and black pepper were bought in local market in Rio de Janeiro, Brazil. The LAXS patterns were obtained using a Shimadzu DRX 6000 diffractometer in reflection geometry. Coherent scattering patterns are measured for the samples for θ=5-35 o . The data were collected in 0.05 o increments every 3 s. In order to evaluate the possible molecular structure changes caused to the irradiation procedure, the signatures obtained for control (non-irradiated) spices were compared with spice samples irradiated with different doses varying from 3 to 40 kGy. The LAXS patterns of all samples were obtained after 30, 60, 90, 120 days to evaluate the effect of storage period. Scattering profiles from spices irradiated with different irradiation doses were obtained and the results compared. For each spice, there is no considerable deviation in shape in function of the irradiation dose. It indicates that the molecular structure of each analyzed spices is preserved considering the dose range chosen. The results show that the molecular structure was found to be stable during storage at the ambient temperature for up to 4 months

X-ray small angle scattering of polymer solutions

International Nuclear Information System (INIS)

Koyama, Ryuzo

1975-01-01

In recent papers, the calculated results were reported on the angular dependence of the intensity of scattered light or X-ray by chain polymers, on the basis of a stiff chain model. As the results, the curves of S 2 P (theta) corresponding to Kratky plot, for different molecular expansion, showed a plateau, and the height of the plateau was proportional to the inverse of molecular expansion coefficient α 2 . But as seen later, there is some possibility that the assumption made in the calculation overestimated the expansion of small segments which theoretically determines scattering curves at large scattering angles, such as the plateau. Accordingly, modified calculation was carried out by adopting the stiff chain polymer model as the previous case. When the contour length of a chain segment is very long, it can be treated approximately as a Gaussian coil, thus the equation for a chain segment expansion coefficient α (t) was obtained. Then the mean square distance of chain segments of polymer molecules was able to be determined, and the equation for a particle scattering factor P(theta) was obtained. The numerical calculation of P(theta) showed that this modified assumption considerably decreased the effect of molecular expansion on P(theta), and the curves of S 2 P(theta) increased monotonously without showing the plateau. The result of this calculation was compared with the experimental curves of polystyrene-toluene solution, and the agreement better than before was obtained. (Kako, I.)

Simulation tools for scattering corrections in spectrally resolved x-ray computed tomography using McXtrace

Science.gov (United States)

Busi, Matteo; Olsen, Ulrik L.; Knudsen, Erik B.; Frisvad, Jeppe R.; Kehres, Jan; Dreier, Erik S.; Khalil, Mohamad; Haldrup, Kristoffer

2018-03-01

Spectral computed tomography is an emerging imaging method that involves using recently developed energy discriminating photon-counting detectors (PCDs). This technique enables measurements at isolated high-energy ranges, in which the dominating undergoing interaction between the x-ray and the sample is the incoherent scattering. The scattered radiation causes a loss of contrast in the results, and its correction has proven to be a complex problem, due to its dependence on energy, material composition, and geometry. Monte Carlo simulations can utilize a physical model to estimate the scattering contribution to the signal, at the cost of high computational time. We present a fast Monte Carlo simulation tool, based on McXtrace, to predict the energy resolved radiation being scattered and absorbed by objects of complex shapes. We validate the tool through measurements using a CdTe single PCD (Multix ME-100) and use it for scattering correction in a simulation of a spectral CT. We found the correction to account for up to 7% relative amplification in the reconstructed linear attenuation. It is a useful tool for x-ray CT to obtain a more accurate material discrimination, especially in the high-energy range, where the incoherent scattering interactions become prevailing (>50 keV).

X-RAYING THE DARK SIDE OF VENUS—SCATTER FROM VENUS’ MAGNETOTAIL?

International Nuclear Information System (INIS)

Afshari, M.; Peres, G.; Petralia, A.; Reale, F.; Jibben, P. R.; Weber, M.

2016-01-01

We analyze significant X-ray, EUV, and UV emission coming from the dark side of Venus observed with Hinode /XRT and Solar Dynamics Observatory /Atmospheric Imaging Assembly ( SDO /AIA) during a transit across the solar disk that occurred in 2012. As a check we have analyzed an analogous Mercury transit that occurred in 2006. We have used the latest version of the Hinode /XRT point spread function to deconvolve Venus and Mercury X-ray images, to remove instrumental scattering. After deconvolution, the flux from Venus’ shadow remains significant while that of Mercury becomes negligible. Since stray light contamination affects the XRT Ti-poly filter data we use, we performed the same analysis with XRT Al-mesh filter data, not affected by the light leak. Even the latter data show residual flux. We have also found significant EUV (304 Å, 193 Å, 335 Å) and UV (1700 Å) flux in Venus’ shadow, measured with SDO /AIA. The EUV emission from Venus’ dark side is reduced, but still significant, when deconvolution is applied. The light curves of the average flux of the shadow in the X-ray, EUV, and UV bands appear different as Venus crosses the solar disk, but in any of them the flux is, at any time, approximately proportional to the average flux in a ring surrounding Venus, and therefore proportional to that of the solar regions around Venus’ obscuring disk line of sight. The proportionality factor depends on the band. This phenomenon has no clear origin; we suggest that it may be due to scatter occurring in the very long magnetotail of Venus.

Time Resolved X-Ray Scattering of molecules in Solution

DEFF Research Database (Denmark)

Brandt van Driel, Tim

The dissertation describes the use of Time-Resolved X-ray Diffuse Scattering (TR-XDS) to study photo-induced structural changes in molecules in solution. The application of the technique is exemplified with experiments on two bimetallic molecules. The main focus is on the data-flow and process......)42+ obtained at European Synchrotron Radiation Facility (ESRF) are presented to exemplify TR-XDS at synchrotrons. Similarly, measurements on Ir2(dimen)42+ are used to show the XFEL data-flow and how it deviates from the prior. A method to identify and account for systematic fluctuations...

Final Report - X-ray Studies of Highly Correlated Systems

Energy Technology Data Exchange (ETDEWEB)

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

2017-11-27

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

First observation of multi-pulse X-ray train via multi-collision laser Compton scattering

International Nuclear Information System (INIS)

Kuroda, R.; Toyokawa, H.; Yasumoto, M.; Ikeura-Sekiguchi, H.; Koike, M.; Yamada, K.; Yanagida, T.; Nakajyo, T.; Sakai, F.

2009-01-01

A compact hard X-ray source via laser Compton scattering (LCS) has been developed for biological and medical applications at the National Institute of Advanced Industrial Science and Technology (AIST) in Japan. The multi-collision LCS has been investigated in order to enhance the X-ray yields. The first observation of multi-pulse X-ray train with 6 pulses via the multi-collision LCS has been successfully demonstrated between the multi-bunch electron train with 6 bunches and the multi-pulse Ti:Sa laser train with 6 pulses. The 32 MeV electron train was generated from a Cs 2 Te photocathode rf gun with a multi-pulse UV laser and the S-band linac. The Ti:Sa laser train was obtained with the chirp pulse amplification (CPA) including the modified regenerative amplifier. The X-ray train with 6 pulses with 12.6 ns spacing was observed with the micro-channel plate (MCP). The maximum energy of the X-ray is analytically estimated to be about 24 keV and the total number of generated photons was calculated to be about 1.8x10 6 photons/train.

Modelling of cation displacements in SrTiO.sub.3./sub. by means of multi-energy anomalous X-ray diffuse scattering

Czech Academy of Sciences Publication Activity Database

Kopecký, Miloš; Fábry, Jan; Kub, Jiří

2016-01-01

Roč. 49, Jun (2016), 1016-1020 ISSN 1600-5767 R&D Projects: GA ČR GA15-04121S Institutional support: RVO:68378271 Keywords : X-ray diffuse scattering * atomic displacements * anomalous X-ray scattering * SrTiO 3 Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.495, year: 2016

X-ray scattering evaluation of ultrastructural changes in human dental tissues with thermal treatment.

Science.gov (United States)

Sandholzer, Michael A; Sui, Tan; Korsunsky, Alexander M; Walmsley, Anthony Damien; Lumley, Philip J; Landini, Gabriel

2014-05-01

Micro- and ultrastructural analysis of burned skeletal remains is crucial for obtaining a reliable estimation of cremation temperature. Earlier studies mainly focused on heat-induced changes in bone tissue, while this study extends this research to human dental tissues using a novel quantitative analytical approach. Twelve tooth sections were burned at 400-900°C (30-min exposure, increments of 100°C). Subsequent combined small- and wide-angle X-ray scattering (SAXS/WAXS) experiments were performed at the Diamond Light Source synchrotron facility, where 28 scattering patterns were collected within each tooth section. In comparison with the control sample, an increase in mean crystal thickness was found in burned dentine (2.8-fold) and enamel (1.4-fold), however at a smaller rate than reported earlier for bone tissue (5-10.7-fold). The results provide a structural reference for traditional X-ray scattering methods and emphasize the need to investigate bone and dental tissues separately to obtain a reliable estimation of cremation temperature. © 2014 American Academy of Forensic Sciences.

Determination of coal ash content by the combined x-ray fluorescence and scattering spectrum

Science.gov (United States)

Mikhailov, I. F.; Baturin, A. A.; Mikhailov, A. I.; Borisova, S. S.; Fomina, L. P.

2018-02-01

An alternative method is proposed for the determination of the inorganic constituent mass fraction (ash) in solid fuel by the ratio of Compton and Rayleigh X-ray scattering peaks IC/IR subject to the iron fluorescence intensity. An original X-ray optical scheme with a Ti/Mo (or Sc/Cu) double-layer secondary radiator allows registration of the combined fluorescence-and-scattering spectrum at the specified scattering angle. An algorithm for linear calibration of the Compton-to-Rayleigh IC/IR ratio is proposed which uses standard samples with two certified characteristics: mass fractions of ash (Ad) and iron oxide (WFe2O3). Ash mass fractions have been determined for coals of different deposits in the wide range of Ad from 9.4% to 52.7% mass and WFe2O3 from 0.3% to 4.95% mass. Due to the high penetrability of the probing radiation with energy E > 17 keV, the sample preparation procedure is rather simplified in comparison with the traditional method of Ad determination by the sum of fluorescence intensities of all constituent elements.

Novel micro-reactor flow cell for investigation of model catalysts using in situ grazing-incidence X-ray scattering

DEFF Research Database (Denmark)

Kehres, Jan; Pedersen, Thomas; Masini, Federico

2016-01-01

at synchrotron facilities are performed utilizing the micro-reactor and a designed transportable gas feed and analysis system. The feasibility of simultaneous in situ GISAXS/GIWAXS experiments in the novel micro-reactor flow cell was confirmed with CO oxidation over mass-selected Ru nanoparticles.......The design, fabrication and performance of a novel and highly sensitive micro-reactor device for performing in situ grazing-incidence X-ray scattering experiments of model catalyst systems is presented. The design of the reaction chamber, etched in silicon on insulator (SIO), permits grazing......-incidence small-angle X-ray scattering (GISAXS) in transmission through 10 µm-thick entrance and exit windows by using micro-focused beams. An additional thinning of the Pyrex glass reactor lid allows simultaneous acquisition of the grazing-incidence wide-angle X-ray scattering (GIWAXS). In situ experiments...

Novel micro-reactor flow cell for investigation of model catalysts using in situ grazing-incidence X-ray scattering

Science.gov (United States)

Kehres, Jan; Pedersen, Thomas; Masini, Federico; Andreasen, Jens Wenzel; Nielsen, Martin Meedom; Diaz, Ana; Nielsen, Jane Hvolbæk; Hansen, Ole

2016-01-01

The design, fabrication and performance of a novel and highly sensitive micro-reactor device for performing in situ grazing-incidence X-ray scattering experiments of model catalyst systems is presented. The design of the reaction chamber, etched in silicon on insulator (SIO), permits grazing-incidence small-angle X-ray scattering (GISAXS) in transmission through 10 µm-thick entrance and exit windows by using micro-focused beams. An additional thinning of the Pyrex glass reactor lid allows simultaneous acquisition of the grazing-incidence wide-angle X-ray scattering (GIWAXS). In situ experiments at synchrotron facilities are performed utilizing the micro-reactor and a designed transportable gas feed and analysis system. The feasibility of simultaneous in situ GISAXS/GIWAXS experiments in the novel micro-reactor flow cell was confirmed with CO oxidation over mass-selected Ru nanoparticles. PMID:26917133

A portable high-field pulsed-magnet system for single-crystal x-ray scattering studies

International Nuclear Information System (INIS)

Islam, Zahirul; Lang, Jonathan C.; Ruff, Jacob P. C.; Ross, Kathryn A.; Gaulin, Bruce D.; Nojiri, Hiroyuki; Matsuda, Yasuhiro H.; Qu Zhe

2009-01-01

We present a portable pulsed-magnet system for x-ray studies of materials in high magnetic fields (up to 30 T). The apparatus consists of a split-pair of minicoils cooled on a closed-cycle cryostat, which is used for x-ray diffraction studies with applied field normal to the scattering plane. A second independent closed-cycle cryostat is used for cooling the sample to near liquid helium temperatures. Pulsed magnetic fields (∼1 ms in total duration) are generated by discharging a configurable capacitor bank into the magnet coils. Time-resolved scattering data are collected using a combination of a fast single-photon counting detector, a multichannel scaler, and a high-resolution digital storage oscilloscope. The capabilities of this instrument are used to study a geometrically frustrated system revealing strong magnetostrictive effects in the spin-liquid state.

X-ray scattering studies of non-equilibrium ordering processes: Progress report, November 1, 1988--October 31, 1989

International Nuclear Information System (INIS)

Nagler, S.E.

1989-01-01

We report on the progress of our project entitled ''X-ray Scattering Studies of Non-Equilibrium Ordering Processes.'' In-house time-resolved x-ray scattering has been used to investigate ordering kinetics in single crystal thin films of Cu 3 Au. Scaling analysis of the results shows that two dimensional kinetic behavior is observed in 260 /angstrom/ thick films. Significant improvements have been made in the local capabilities for fast time resolved measurements and data analysis. Measurements of microphase separation and ordering kinetics have been made in block-co-polymers, and experiments on Au-Cd martensitic material are continuing. 15 refs., 7 figs

Strongly correlated electrons at high pressure: an approach by inelastic X-Ray scattering

International Nuclear Information System (INIS)

Rueff, J.P.

2007-06-01

Inelastic X-ray scattering (IXS) and associated methods has turn out to be a powerful alternative for high-pressure physics. It is an all-photon technique fully compatible with high-pressure environments and applicable to a vast range of materials. Standard focalization of X-ray in the range of 100 microns is typical of the sample size in the pressure cell. Our main aim is to provide an overview of experimental results obtained by IXS under high pressure in 2 classes of materials which have been at the origin of the renewal of condensed matter physics: strongly correlated transition metal oxides and rare-earth compounds. Under pressure, d and f-electron materials show behaviors far more complex that what would be expected from a simplistic band picture of electron delocalization. These spectroscopic studies have revealed unusual phenomena in the electronic degrees of freedom, brought up by the increased density, the changes in the charge-carrier concentration, the over-lapping between orbitals, and hybridization under high pressure conditions. Particularly we discuss about pressure induced magnetic collapse and metal-insulator transitions in 3d compounds and valence fluctuations phenomena in 4f and 5f compounds. Thanks to its superior penetration depth, chemical selectivity and resonant enhancement, resonant inelastic X-ray scattering has appeared extremely well suited to high pressure physics in strongly correlated materials. (A.C.)

Quantitative X-ray mapping, scatter diagrams and the generation of correction maps to obtain more information about your material

Science.gov (United States)

Wuhrer, R.; Moran, K.

2014-03-01

Quantitative X-ray mapping with silicon drift detectors and multi-EDS detector systems have become an invaluable analysis technique and one of the most useful methods of X-ray microanalysis today. The time to perform an X-ray map has reduced considerably with the ability to map minor and trace elements very accurately due to the larger detector area and higher count rate detectors. Live X-ray imaging can now be performed with a significant amount of data collected in a matter of minutes. A great deal of information can be obtained from X-ray maps. This includes; elemental relationship or scatter diagram creation, elemental ratio mapping, chemical phase mapping (CPM) and quantitative X-ray maps. In obtaining quantitative x-ray maps, we are able to easily generate atomic number (Z), absorption (A), fluorescence (F), theoretical back scatter coefficient (η), and quantitative total maps from each pixel in the image. This allows us to generate an image corresponding to each factor (for each element present). These images allow the user to predict and verify where they are likely to have problems in our images, and are especially helpful to look at possible interface artefacts. The post-processing techniques to improve the quantitation of X-ray map data and the development of post processing techniques for improved characterisation are covered in this paper.

Quantitative X-ray mapping, scatter diagrams and the generation of correction maps to obtain more information about your material

International Nuclear Information System (INIS)

Wuhrer, R; Moran, K

2014-01-01

Quantitative X-ray mapping with silicon drift detectors and multi-EDS detector systems have become an invaluable analysis technique and one of the most useful methods of X-ray microanalysis today. The time to perform an X-ray map has reduced considerably with the ability to map minor and trace elements very accurately due to the larger detector area and higher count rate detectors. Live X-ray imaging can now be performed with a significant amount of data collected in a matter of minutes. A great deal of information can be obtained from X-ray maps. This includes; elemental relationship or scatter diagram creation, elemental ratio mapping, chemical phase mapping (CPM) and quantitative X-ray maps. In obtaining quantitative x-ray maps, we are able to easily generate atomic number (Z), absorption (A), fluorescence (F), theoretical back scatter coefficient (η), and quantitative total maps from each pixel in the image. This allows us to generate an image corresponding to each factor (for each element present). These images allow the user to predict and verify where they are likely to have problems in our images, and are especially helpful to look at possible interface artefacts. The post-processing techniques to improve the quantitation of X-ray map data and the development of post processing techniques for improved characterisation are covered in this paper

Multiple scattering in grazing-incidence X-ray diffraction: impact on lattice-constant determination in thin films

Energy Technology Data Exchange (ETDEWEB)

Resel, Roland, E-mail: roland.resel@tugraz.at; Bainschab, Markus; Pichler, Alexander [Graz University of Technology, Graz (Austria); Dingemans, Theo [Delft University of Technology, Delft (Netherlands); Simbrunner, Clemens [Johannes Kepler University, Linz (Austria); University of Bremen, Bremen (Germany); Stangl, Julian [Johannes Kepler University, Linz (Austria); Salzmann, Ingo [Humboldt University, Berlin (Germany)

2016-04-20

The use of grazing-incidence X-ray diffraction to determine the crystal structure from thin films requires accurate positions of Bragg peaks. Refraction effects and multiple scattering events have to be corrected or minimized. Dynamical scattering effects are observed in grazing-incidence X-ray diffraction experiments using an organic thin film of 2,2′:6′,2′′-ternaphthalene grown on oxidized silicon as substrate. Here, a splitting of all Bragg peaks in the out-of-plane direction (z-direction) has been observed, the magnitude of which depends both on the incidence angle of the primary beam and the out-of-plane angle of the scattered beam. The incident angle was varied between 0.09° and 0.25° for synchrotron radiation of 10.5 keV. This study reveals comparable intensities of the split peaks with a maximum for incidence angles close to the critical angle of total external reflection of the substrate. This observation is rationalized by two different scattering pathways resulting in diffraction peaks at different positions at the detector. In order to minimize the splitting, the data suggest either using incident angles well below the critical angle of total reflection or angles well above, which sufficiently attenuates the contributions from the second scattering path. This study highlights that the refraction of X-rays in (organic) thin films has to be corrected accordingly to allow for the determination of peak positions with sufficient accuracy. Based thereon, a reliable determination of the lattice constants becomes feasible, which is required for crystallographic structure solutions from thin films.

Bone X-Ray (Radiography)

Medline Plus

Full Text Available ... standards used by radiology professionals. Modern x-ray systems have very controlled x-ray beams and dose control methods to minimize stray (scatter) radiation. This ensures that those parts of a patient's body not being imaged receive minimal radiation exposure. ...

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

International Nuclear Information System (INIS)

Chubar, Oleg; Kocharyan, Vitali; Saldin, Evgeni; Serkez, Svitozar; Shvyd'ko, Yuri

2015-08-01

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

Introducing a New Capability at SSRL: Resonant Soft X-ray Scattering

Science.gov (United States)

Lee, Jun-Sik; Jang, Hoyoung; Lu, Donghui; Kao, Chi-Chang

Stanford Synchrotron Radiation Lightsource (SSRL) at SLAC recently developed a setup for the resonant soft x-ray scattering (RSXS). In general, the RSXS technique uniquely probes not only structural information, but also chemical specific information. This is because this technique can explore the spatial periodicities of charge, orbital, spin, and lattice with spectroscopic aspect. Moreover, the soft x-ray range is particularly relevant for a study of soft materials as it covers the K-edge of C, N, F, and O, as well as the L-edges of transition metals and M-edges of rare-earth elements. Hence, the RSXS capability has been regarded as a very powerful technique for investigating the intrinsic properties of materials such as quantum- and energy-materials. The RSXS capability at the SSRL composes of in-vacuum 4-circle diffractometer. There are also the fully motorized sample-motion manipulations. Also, the sample can be cooled down to 25 K via the liquid helium. This capability has been installed at BL 13-3, where the photon source is from elliptically polarized undulator (EPU). Covering the photon energies is from 230 eV to 1400 eV. Furthermore, this EPU system offers more degree of freedoms for controlling x-ray polarizations (linear and circular). Using the advance of controlling x-ray polarization, we can also investigate a morphology effect of local domain/grain in materials. The detailed introduction of the RSXS end-station and several results will be touched in this poster presentation.

Study of human blood and hemocomponents irradiated by low angle x ray scattering (LAXS)

Energy Technology Data Exchange (ETDEWEB)

Pinto, Nivia G. Villela; Barroso, Regina C. [Universidade do Estado do Rio de Janeiro (UERJ), RJ (Brazil). Inst. de Fisica. Dept. de Fisica Aplicada e Termodinamica], e-mail: nitatag@gmail.com; Mota, Carla L.S.; Almeida, Andre P.; Azeredo, Soraia R.; Braz, Delson [Coordenacao dos Programas de Pos-graduacao em Engenharia (COPPE/UFRJ), RJ (Brazil). Lab. de Instrumentacao Nuclear], e-mail: delson@lin.ufrj.br

2009-07-01

Irradiation of blood and blood components is currently practiced in developed and in a few developing countries. The main purpose of this process is the prevention of graft versus host disease in immunodeficient patients. The Food and Drug Administration recommends a dose range of 15 Gy to 25 Gy for these blood components. When x-ray photons are scattered from biological samples, their angular distribution shows one or more peaks in the forward direction of scattering. These peaks are characteristic for the investigated samples. Due to its wide range of biological and medical applications, low-angle x-ray scattering has attracted the attention of many authors. Thus in this present work was studied the possible variations in scattering profiles due to the irradiation when the gender of patients was considered. Fresh blood specimens were obtained from volunteers using vacutainer tubes containing EDTA, at the Dr. Eliel Figueiredo Laboratory, Rio de Janeiro. All the samples were lyophilized for 48 hours in a freeze drier in order to remove the water. The scattering measurements were carried out in e-2e reflection geometry using a powder diffractometer Shimadzu XRD- 6000. The measured characterization parameters for LAXS were associated with epidemiological data (gender). The mean values of the different parameters were compared using the Students's t-test for each characterization parameters. The scattering profiles from plasma and formed elements are characterized by the presence of two peaks in the forward direction of scattering. For epidemiological data (gender) analyzed was not found significant changes in the mostly of characterization parameters (p>0.05). (author)

Study of human blood and hemocomponents irradiated by low angle x ray scattering (LAXS)

International Nuclear Information System (INIS)

Pinto, Nivia G. Villela; Barroso, Regina C.; Mota, Carla L.S.; Almeida, Andre P.; Azeredo, Soraia R.; Braz, Delson

2009-01-01

Irradiation of blood and blood components is currently practiced in developed and in a few developing countries. The main purpose of this process is the prevention of graft versus host disease in immunodeficient patients. The Food and Drug Administration recommends a dose range of 15 Gy to 25 Gy for these blood components. When x-ray photons are scattered from biological samples, their angular distribution shows one or more peaks in the forward direction of scattering. These peaks are characteristic for the investigated samples. Due to its wide range of biological and medical applications, low-angle x-ray scattering has attracted the attention of many authors. Thus in this present work was studied the possible variations in scattering profiles due to the irradiation when the gender of patients was considered. Fresh blood specimens were obtained from volunteers using vacutainer tubes containing EDTA, at the Dr. Eliel Figueiredo Laboratory, Rio de Janeiro. All the samples were lyophilized for 48 hours in a freeze drier in order to remove the water. The scattering measurements were carried out in e-2e reflection geometry using a powder diffractometer Shimadzu XRD- 6000. The measured characterization parameters for LAXS were associated with epidemiological data (gender). The mean values of the different parameters were compared using the Students's t-test for each characterization parameters. The scattering profiles from plasma and formed elements are characterized by the presence of two peaks in the forward direction of scattering. For epidemiological data (gender) analyzed was not found significant changes in the mostly of characterization parameters (p>0.05). (author)

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

Energy Technology Data Exchange (ETDEWEB)

Coleman, J. E. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Welch, D. R.; Miller, C. L. [Voss Scientific, Albuquerque, New Mexico 87108 (United States)

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.

Femtosecond X-Ray Scattering Study of Ultrafast Photoinduced Structural Dynamics in Solvated [Co(terpy)2]2+

DEFF Research Database (Denmark)

Biasin, Elisa; Brandt van Driel, Tim; Kjær, Kasper Skov

2016-01-01

We study the structural dynamics of photoexcited [Co(terpy)2]2+ in an aqueous solution with ultrafast x-ray diffuse scattering experiments conducted at the Linac Coherent Light Source. Through direct comparisons with density functional theory calculations, our analysis shows that the photoexcitat......We study the structural dynamics of photoexcited [Co(terpy)2]2+ in an aqueous solution with ultrafast x-ray diffuse scattering experiments conducted at the Linac Coherent Light Source. Through direct comparisons with density functional theory calculations, our analysis shows...... find that the equilibrium bond-elongated structure of the high spin state is established on a single-picosecond time scale and that this state has a lifetime of ∼7 ps....

Quantitative characterization of fatty liver disease using x-ray scattering

Science.gov (United States)

Elsharkawy, Wafaa B.; Elshemey, Wael M.

2013-11-01

Nonalcoholic fatty liver disease (NAFLD) is a dynamic condition in which fat abnormally accumulates within the hepatocytes. It is believed to be a marker of risk of later chronic liver diseases, such as liver cirrhosis and carcinoma. The fat content in liver biopsies determines its validity for liver transplantation. Transplantation of livers with severe NAFLD is associated with a high risk of primary non-function. Moreover, NAFLD is recognized as a clinically important feature that influences patient morbidity and mortality after hepatic resection. Unfortunately, there is a lack in a precise, reliable and reproducible method for quantification of NAFLD. This work suggests a method for the quantification of NAFLD. The method is based on the fact that fatty liver tissue would have a characteristic x-ray scattering profile with a relatively intense fat peak at a momentum transfer value of 1.1 nm-1 compared to a soft tissue peak at 1.6 nm-1. The fat content in normal and fatty liver is plotted against three profile characterization parameters (ratio of peak intensities, ratio of area under peaks and ratio of area under fat peak to total profile area) for measured and Monte Carlo simulated x-ray scattering profiles. Results show a high linear dependence (R2>0.9) of the characterization parameters on the liver fat content with a reported high correlation coefficient (>0.9) between measured and simulated data. These results indicate that the current method probably offers reliable quantification of fatty liver disease.

Structure factor of dimyristoylphosphatidylcholine unilamellar vesicles: small-angle x-ray scattering study

International Nuclear Information System (INIS)

Kiselev, M.A.; Aksenov, V.L.; Lombardo, D.; Kisselev, A.M.; Lesieur, P.

2003-01-01

Small-angle X-ray scattering (SAXS) experiments have been performed on dimyristoylphosphatidylcholine (DMPC) unilamellar vesicles in 40% aqueous sucrose solution. Model of separated form factors was applied for the evaluation of SAXS curves from large unilamellar vesicles. For the first time vesicle structure factor, polydispersity, average radius and membrane thickness were calculated simultaneously from the SAXS curves at T=30 deg C for DMPC concentrations in the range from 15 to 75 mM (1-5% w/w). Structure factor correction to the scattering curve was shown to be negligibly small for the lipid concentration of 15 mM (1% w/w). It was proved to be necessary to introduce structure factor correction to the scattering curves for lipid concentrations ≥ 30 mM (2% w/w)

Structure Factor of Dimyristoylphosphatidylcholine Unilamellar Vesicles Small-Angle X-Ray Scattering Study

CERN Document Server

Kiselev, M A; Kisselev, A M; Lesieur, P; Aksenov, V L

2003-01-01

Small-angle X-ray scattering (SAXS) experiments have been performed on dimyristoylphosphatidylcholine (DMPC) unilamellar vesicles in 40 % aqueous sucrose solution. Model of separated form factors was applied for the evaluation of SAXS curves from large unilamellar vesicles. For the first time vesicle structure factor, polydispersity, average radius and membrane thickness were calculated simultaneously from the SAXS curves at T=306{\\circ}C for DMPC concentrations in the range from 15 to 75 mM (1-5 % w/w). Structure factor correction to the scattering curve was shown to be negligibly small for the lipid concentration of 15 mM (1 % w/w). It was proved to be necessary to introduce structure factor correction to the scattering curves for lipid concentrations {\\ge}30 mM (2 % w/w).

Revisiting Bragg's X-ray microscope: scatter based optical transient grating detection of pulsed ionising radiation.

Science.gov (United States)

Fullagar, Wilfred K; Paganin, David M; Hall, Chris J

2011-06-01

Transient optical gratings for detecting ultrafast signals are routine for temporally resolved photochemical investigations. Many processes can contribute to the formation of such gratings; we indicate use of optically scattering centres that can be formed with highly variable latencies in different materials and devices using ionising radiation. Coherent light scattered by these centres can form the short-wavelength-to-optical-wavelength, incoherent-to-coherent basis of a Bragg X-ray microscope, with inherent scope for optical phasing. Depending on the dynamics of the medium chosen, the way is open to both ultrafast pulsed and integrating measurements. For experiments employing brief pulses, we discuss high-dynamic-range short-wavelength diffraction measurements with real-time optical reconstructions. Applications to optical real-time X-ray phase-retrieval are considered. Copyright © 2010 Elsevier B.V. All rights reserved.

Human soft tissue analysis using x-ray or gamma-ray techniques

International Nuclear Information System (INIS)

Theodorakou, C; Farquharson, M J

2008-01-01

This topical review is intended to describe the x-ray techniques used for human soft tissue analysis. X-ray techniques have been applied to human soft tissue characterization and interesting results have been presented over the last few decades. The motivation behind such studies is to provide improved patient outcome by using the data obtained to better understand a disease process and improve diagnosis. An overview of theoretical background as well as a complete set of references is presented. For each study, a brief summary of the methodology and results is given. The x-ray techniques include x-ray diffraction, x-ray fluorescence, Compton scattering, Compton to coherent scattering ratio and attenuation measurements. The soft tissues that have been classified using x-rays or gamma rays include brain, breast, colon, fat, kidney, liver, lung, muscle, prostate, skin, thyroid and uterus. (topical review)

Synchrotron X-ray scattering studies at mineral-water interfaces

International Nuclear Information System (INIS)

Chiarello, R.P.; Sturchio, N.C.

1995-01-01

Synchrotron X-ray scattering techniques provide a powerful tool for the in situ study of atomic scale processes occurring at solid-liquid interfaces. We have applied these techniques to characterize and study reactions at mineral-water interfaces. Here we present two examples. The first is the characterization of the calcite (CaCO 3 ) (10 bar 14) cleavage surface, in equilibrium with deionized water, by crystal truncation rod measurements. The second is the in situ study of the heteroepitaxial growth of otavite (CdCO 3 ) on the calcite (10 bar 14) cleavage surface. The results of such studies will lead to significant progress in understanding mineral-water interface geochemistry

Breast tissue classification using x-ray scattering measurements and multivariate data analysis

Science.gov (United States)

Ryan, Elaine A.; Farquharson, Michael J.

2007-11-01

This study utilized two radiation scatter interactions in order to differentiate malignant from non-malignant breast tissue. These two interactions were Compton scatter, used to measure the electron density of the tissues, and coherent scatter to obtain a measure of structure. Measurements of these parameters were made using a laboratory experimental set-up comprising an x-ray tube and HPGe detector. The breast tissue samples investigated comprise five different tissue classifications: adipose, malignancy, fibroadenoma, normal fibrous tissue and tissue that had undergone fibrocystic change. The coherent scatter spectra were analysed using a peak fitting routine, and a technique involving multivariate analysis was used to combine the peak fitted scatter profile spectra and the electron density values into a tissue classification model. The number of variables used in the model was refined by finding the sensitivity and specificity of each model and concentrating on differentiating between two tissues at a time. The best model that was formulated had a sensitivity of 54% and a specificity of 100%.

Breast tissue classification using x-ray scattering measurements and multivariate data analysis

Energy Technology Data Exchange (ETDEWEB)

Ryan, Elaine A; Farquharson, Michael J [School of Allied Health Sciences, City University, Charterhouse Square, London EC1M 6PA (United Kingdom)

2007-11-21

This study utilized two radiation scatter interactions in order to differentiate malignant from non-malignant breast tissue. These two interactions were Compton scatter, used to measure the electron density of the tissues, and coherent scatter to obtain a measure of structure. Measurements of these parameters were made using a laboratory experimental set-up comprising an x-ray tube and HPGe detector. The breast tissue samples investigated comprise five different tissue classifications: adipose, malignancy, fibroadenoma, normal fibrous tissue and tissue that had undergone fibrocystic change. The coherent scatter spectra were analysed using a peak fitting routine, and a technique involving multivariate analysis was used to combine the peak fitted scatter profile spectra and the electron density values into a tissue classification model. The number of variables used in the model was refined by finding the sensitivity and specificity of each model and concentrating on differentiating between two tissues at a time. The best model that was formulated had a sensitivity of 54% and a specificity of 100%.

Crystal structure and tautomerism of Pigment Yellow 138 determined by X-ray powder diffraction and solid-state NMR

DEFF Research Database (Denmark)

Gumbert, Silke D.; Körbitzer, Meike; Alig, Edith

2016-01-01

The crystal structure of C.I. Pigment Yellow 138 was determined from X-ray powder diffraction data using real-space methods with subsequent Rietveld refinements. The tautomeric state was investigated by solid-state 1D and 2D multinuclear NMR experiments. In the crystals, the compound exhibits...... the NH-tautomer with a hydrogen atom situated at the nitrogen of the quinoline moiety. Direct evidence of the presence of the NH-tautomer is provided by 1H–14N HMQC solid-state NMR at very fast MAS. Solid-state dispersion-corrected density functional theory calculations with BLYP-D3 confirm...

Compton scattering artifacts in electron excited X-ray spectra measured with a silicon drift detector.

Science.gov (United States)

Ritchie, Nicholas W M; Newbury, Dale E; Lindstrom, Abigail P

2011-12-01

Artifacts are the nemesis of trace element analysis in electron-excited energy dispersive X-ray spectrometry. Peaks that result from nonideal behavior in the detector or sample can fool even an experienced microanalyst into believing that they have trace amounts of an element that is not present. Many artifacts, such as the Si escape peak, absorption edges, and coincidence peaks, can be traced to the detector. Others, such as secondary fluorescence peaks and scatter peaks, can be traced to the sample. We have identified a new sample-dependent artifact that we attribute to Compton scattering of energetic X-rays generated in a small feature and subsequently scattered from a low atomic number matrix. It seems likely that this artifact has not previously been reported because it only occurs under specific conditions and represents a relatively small signal. However, with the advent of silicon drift detectors and their utility for trace element analysis, we anticipate that more people will observe it and possibly misidentify it. Though small, the artifact is not inconsequential. Under some conditions, it is possible to mistakenly identify the Compton scatter artifact as approximately 1% of an element that is not present.

Magnetic excitations and phase separation in the underdoped La2-xSrxCuO4 superconductor measured by resonant inelastic X-ray scattering.

Science.gov (United States)

Braicovich, L; van den Brink, J; Bisogni, V; Sala, M Moretti; Ament, L J P; Brookes, N B; De Luca, G M; Salluzzo, M; Schmitt, T; Strocov, V N; Ghiringhelli, G

2010-02-19

We probe the collective magnetic modes of La2CuO4 and underdoped La2-xSrxCuO4 (LSCO) by momentum resolved resonant inelastic x-ray scattering (RIXS) at the Cu L3 edge. For the undoped antiferromagnetic sample, we show that the single magnon dispersion measured with RIXS coincides with the one determined by inelastic neutron scattering, thus demonstrating that x rays are an alternative to neutrons in this field. In the spin dynamics of LSCO, we find a branch dispersing up to approximately 400 meV coexisting with one at lower energy. The high-energy branch has never been seen before. It indicates that underdoped LSCO is in a dynamic inhomogeneous spin state.

An experimental implementation of the 90 .deg. compton scattering inspection method for identifying explosive materials using dual energy x-ray

International Nuclear Information System (INIS)

Park, Ji Sung

2012-02-01

In order to obtain the physical properties of an inspection object using an X-ray source, the energy-resolving X-ray method, reflecting the characteristic of continuous energy, is a very useful tool. In this study, the effective atomic number (Z eff ) and normal density (ρ) obtained by the source weighting method on a dual energy X-ray inspection system are presented and demonstrated by experimental implementation. Two X-ray beams of the suggested method were designed using the XCOMP5r code. The filter design of a high energy X-ray source was fixed as 3.5 mm Sn at 150 kVp tube voltage, and the new high energy X-ray beam was named as IN150. The filter design of a low energy X-ray source was also fixed as 0.5 mm Sn at 90 kVp tube voltage, and the new beam was named as IN90. Benchmark calculations by MCNP simulation experiments were performed using four different materials, i.e., Polyethylene, Acetal, Urethane, and TNT. The results of the benchmark calculation showed that the new method can estimate the effective atomic number and the normal density of a scattered object accurately, even when the object was arbitrarily located in samples. Finally to verify the proposed new method, scattering experiments using various polymerized compounds were carried out. The effective attenuation coefficients (μ 1 , μ 2 ) of the experiment objects at the source energies E 1 and E 2 , were calculated using scattered spectra. The effective atomic number and the normal density were then calculated by using the ratio of μ 1 to μ 2 . As a result in case of all sample geometries, the relative differences between the calculation value and the reference value for the effective atomic numbers of each material were within 14 %, and the relative differences for the normal densities were within 12 %. This observation led us to the conclusion that the new 90 .deg. Compton scattering method for identifying explosive materials using a dual-energy X-ray is valid for calculating effective

X-Ray Scattering Studies of the Liquid-Vapor Interface of Gallium.

Science.gov (United States)

Kawamoto, Eric Hitoshi

A UHV system was developed for performing X-ray scattering studies and in situ analyses of liquid metal surfaces. A nearly ideal choice for this study, gallium has a melting point just above room temperature; is amenable to handling in both air and vacuum; its surface oxides can be removed while its cleanliness is maintained and monitored. Using argon glow-discharge sputtering techniques to remove intervening surface oxides, thin wetting layers of gallium were prepared atop nonreactive substrates, to be used as samples suited for liquid surface scattering experiments. Preliminary measurements of X-ray reflectivity from the liquid-vapor interface of gallium were performed with the X-ray UHV chamber configured for use in conjunction with liquid surface spectrometers at two synchrotron beamlines. A novel technique for carrying out and interpreting scattering measurements from curved liquid surfaces was demonstrated. The energy tunability and intense focused white beam flux from a wiggler source was shown to place within reach the large values of wavevector transfer at which specular reflectivity data yield small length scale information about surface structure. Various theoretical treatments and simulations predict quasi-lamellar ordering of atoms near the free surface of metallic liquids due to energetics particular to metals (electron delocalization, the dependence of system energy on ion and electron densities, surface tension and electrostatic energy). However, the experimental data reported to date is insufficient to distinguish between a monotonic, sigmoidal electron density profile found at the free surfaces of dielectric liquids, and the damped oscillatory layer-like profiles anticipated for metallic liquids. Out to a wavevector transfer of Q = 0.55 A ^{-1}, the reflectivity data measured from a curved Ga surface is not inconsistent with what is expected for a liquid-vapor electron density profile of Gaussian width sigma = 1.3 +/- 0.2 A. Subsequent

Disappearance of the laue spots of the downward X-ray diffraction and huge recoil Thomson scattering in solid helium as some prominent peculiarities of a quantum crystal

Energy Technology Data Exchange (ETDEWEB)

Nakajima, Tetsuo

1996-02-01

In topographs of the downward X-ray diffraction, no Laue spots could be observed using a horizontally thin line-focussed beam. The disappearance of the Laue spots by the downward X-ray diffraction could be explained by two main factors besides a synergistic effect of the smallness of the atomic-scattering factors, the absorption coefficients, the densities etc. One is that the downward X-ray diffraction is completely inelastic scattering, and, as a result, diffracted X-ray beams may become entirely diffuse scattering. The other is that the great difference in the linear scatterer density between the forward and downward directions resulted from the fact that the irradiation of a line-focussed X-ray beam to take section topographs weakens the downward X-ray diffraction. The main reason is not due to the zero-point vibration. (J.P.N.).

Disappearance of the laue spots of the downward X-ray diffraction and huge recoil Thomson scattering in solid helium as some prominent peculiarities of a quantum crystal

International Nuclear Information System (INIS)

Nakajima, Tetsuo.

1996-02-01

In topographs of the downward X-ray diffraction, no Laue spots could be observed using a horizontally thin line-focussed beam. The disappearance of the Laue spots by the downward X-ray diffraction could be explained by two main factors besides a synergistic effect of the smallness of the atomic-scattering factors, the absorption coefficients, the densities etc. One is that the downward X-ray diffraction is completely inelastic scattering, and, as a result, diffracted X-ray beams may become entirely diffuse scattering. The other is that the great difference in the linear scatterer density between the forward and downward directions resulted from the fact that the irradiation of a line-focussed X-ray beam to take section topographs weakens the downward X-ray diffraction. The main reason is not due to the zero-point vibration. (J.P.N.)

Bone X-Ray (Radiography)

Medline Plus

Full Text Available ... have very controlled x-ray beams and dose control methods to minimize stray (scatter) radiation. This ensures that those parts of a patient's body not being imaged receive minimal radiation exposure. top of page What are the limitations of Bone X-ray (Radiography)? ...

Energy-angle correlation correction algorithm for monochromatic computed tomography based on Thomson scattering X-ray source

Science.gov (United States)

Chi, Zhijun; Du, Yingchao; Huang, Wenhui; Tang, Chuanxiang

2017-12-01

The necessity for compact and relatively low cost x-ray sources with monochromaticity, continuous tunability of x-ray energy, high spatial coherence, straightforward polarization control, and high brightness has led to the rapid development of Thomson scattering x-ray sources. To meet the requirement of in-situ monochromatic computed tomography (CT) for large-scale and/or high-attenuation materials based on this type of x-ray source, there is an increasing demand for effective algorithms to correct the energy-angle correlation. In this paper, we take advantage of the parametrization of the x-ray attenuation coefficient to resolve this problem. The linear attenuation coefficient of a material can be decomposed into a linear combination of the energy-dependent photoelectric and Compton cross-sections in the keV energy regime without K-edge discontinuities, and the line integrals of the decomposition coefficients of the above two parts can be determined by performing two spectrally different measurements. After that, the line integral of the linear attenuation coefficient of an imaging object at a certain interested energy can be derived through the above parametrization formula, and monochromatic CT can be reconstructed at this energy using traditional reconstruction methods, e.g., filtered back projection or algebraic reconstruction technique. Not only can monochromatic CT be realized, but also the distributions of the effective atomic number and electron density of the imaging object can be retrieved at the expense of dual-energy CT scan. Simulation results validate our proposal and will be shown in this paper. Our results will further expand the scope of application for Thomson scattering x-ray sources.

Preparing Monodisperse Macromolecular Samples for Successful Biological Small-Angle X-ray and Neutron Scattering Experiments

Science.gov (United States)

Jeffries, Cy M.; Graewert, Melissa A.; Blanchet, Clément E.; Langley, David B.; Whitten, Andrew E.; Svergun, Dmitri I

2017-01-01

Small-angle X-ray and neutron scattering (SAXS and SANS) are techniques used to extract structural parameters and determine the overall structures and shapes of biological macromolecules, complexes and assemblies in solution. The scattering intensities measured from a sample contain contributions from all atoms within the illuminated sample volume including the solvent and buffer components as well as the macromolecules of interest. In order to obtain structural information, it is essential to prepare an exactly matched solvent blank so that background scattering contributions can be accurately subtracted from the sample scattering to obtain the net scattering from the macromolecules in the sample. In addition, sample heterogeneity caused by contaminants, aggregates, mismatched solvents, radiation damage or other factors can severely influence and complicate data analysis so it is essential that the samples are pure and monodisperse for the duration of the experiment. This Protocol outlines the basic physics of SAXS and SANS and reveals how the underlying conceptual principles of the techniques ultimately ‘translate’ into practical laboratory guidance for the production of samples of sufficiently high quality for scattering experiments. The procedure describes how to prepare and characterize protein and nucleic acid samples for both SAXS and SANS using gel electrophoresis, size exclusion chromatography and light scattering. Also included are procedures specific to X-rays (in-line size exclusion chromatography SAXS) and neutrons, specifically preparing samples for contrast matching/variation experiments and deuterium labeling of proteins. PMID:27711050

Study of humic acids by small-angle X-ray and neutron scattering

International Nuclear Information System (INIS)

Timchenko, A.; Trubetskaya, O.; Kihara, H.

1999-01-01

Humic acids are an important component of natural ecological system and represent a polydisperse complex of natural biopolymers with molecular masses from several to hundreds kilodaltons. They are both a source of organic compounds and a protector against anthropogenic pollutions of biosphere. The aim of the report is to underline some possibilities of small-angle X-ray and neutron scattering to study HA and their fractions. (author)

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

International Nuclear Information System (INIS)

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

The magnetic order of GdMn₂Ge₂ studied by neutron diffraction and x-ray resonant magnetic scattering.

Science.gov (United States)

Granovsky, S A; Kreyssig, A; Doerr, M; Ritter, C; Dudzik, E; Feyerherm, R; Canfield, P C; Loewenhaupt, M

2010-06-09

The magnetic structure of GdMn₂Ge₂ (tetragonal I4/mmm) has been studied by hot neutron powder diffraction and x-ray resonant magnetic scattering techniques. These measurements, along with the results of bulk experiments, confirm the collinear ferrimagnetic structure with moment direction parallel to the c-axis below T(C) = 96 K and the collinear antiferromagnetic phase in the temperature region T(C) < T < T(N) = 365 K. In the antiferromagnetic phase, x-ray resonant magnetic scattering has been detected at Mn K and Gd L₂ absorption edges. The Gd contribution is a result of an induced Gd 5d electron polarization caused by the antiferromagnetic order of Mn-moments.

Measurement of high-dynamic range x-ray Thomson scattering spectra for the characterization of nano-plasmas at LCLS

Energy Technology Data Exchange (ETDEWEB)

MacDonald, M. J., E-mail: macdonm@umich.edu [University of Michigan, Ann Arbor, Michigan 48109 (United States); SLAC National Accelerator Laboratory, Menlo Park, California 94025 (United States); Gorkhover, T. [SLAC National Accelerator Laboratory, Menlo Park, California 94025 (United States); Technische Universität, 10623 Berlin (Germany); Bachmann, B.; Hau-Riege, S. P.; Pardini, T.; Döppner, T. [Lawrence Livermore National Laboratory, Livermore, California 94551 (United States); Bucher, M. [SLAC National Accelerator Laboratory, Menlo Park, California 94025 (United States); Argonne National Lab, Lemont, Illinois 60439 (United States); Carron, S. [California Lutheran University, Thousand Oaks, California 91360 (United States); Coffee, R. N.; Fletcher, L. B.; Gamboa, E. J.; Glenzer, S. H.; Göde, S.; Krzywinski, J.; O’Grady, C. P.; Osipov, T.; Swiggers, M. [SLAC National Accelerator Laboratory, Menlo Park, California 94025 (United States); Drake, R. P. [University of Michigan, Ann Arbor, Michigan 48109 (United States); Ferguson, K. R. [SLAC National Accelerator Laboratory, Menlo Park, California 94025 (United States); Stanford University, Stanford, California 94305 (United States); Kraus, D. [University of California, Berkeley, California 94720 (United States); and others

2016-11-15

Atomic clusters can serve as ideal model systems for exploring ultrafast (∼100 fs) laser-driven ionization dynamics of dense matter on the nanometer scale. Resonant absorption of optical laser pulses enables heating to temperatures on the order of 1 keV at near solid density conditions. To date, direct probing of transient states of such nano-plasmas was limited to coherent x-ray imaging. Here we present the first measurement of spectrally resolved incoherent x-ray scattering from clusters, enabling measurements of transient temperature, densities, and ionization. Single shot x-ray Thomson scattering signals were recorded at 120 Hz using a crystal spectrometer in combination with a single-photon counting and energy-dispersive pnCCD. A precise pump laser collimation scheme enabled recording near background-free scattering spectra from Ar clusters with an unprecedented dynamic range of more than 3 orders of magnitude. Such measurements are important for understanding collective effects in laser-matter interactions on femtosecond time scales, opening new routes for the development of schemes for their ultrafast control.

Small-angle and wide-angle X-ray scattering study on the bilayer structure of synthetic and bovine heart cardiolipins

International Nuclear Information System (INIS)

Takahashi, Hiroshi; Hayakawa, Tomohiro; Ito, Kazuki; Takata, Masaki; Kobayashi, Toshihide

2010-01-01

Cardiolipin (CL) is a membrane phospholipid containing four fatty acid chains. CL plays an important role in energy transformation in mitochondria. The disorder of CL biosynthesis is involved in a genetic disease, Barth syndrome. Alteration of fatty acid composition of CLs has been found in Barth syndrome patients, i.e., the decrease of unsaturated fatty acid chains. In this study, we investigated how the degree of saturation alters the structure of CL bilayers by using X-ray scattering. Bovine heart CL and two synthetic CLs were compared. Fatty acid compositions of these three CLs have different saturation. Small-angle X-ray scattering data showed that the decrease of the number of double bonds in the unsaturated fatty acid chains causes to thicken the CL bilayers. In addition, wide-angle X-ray scattering data suggested that the decrease reduces the degree of disorder of the hydrophobic region in a liquid crystalline phase. These results may be related to the dysfunction of mitochondria in Barth syndrome.

Small-angle and wide-angle X-ray scattering study on the bilayer structure of synthetic and bovine heart cardiolipins

Energy Technology Data Exchange (ETDEWEB)

Takahashi, Hiroshi [Biophysics Laboratory, Department of Chemistry and Chemical Biology, Gunma University, Maebashi, Gunma, 371-8510 (Japan); Hayakawa, Tomohiro [Life Science Laboratory, Advanced Materials Laboratories, Sony Corporation, Yushima, Bunkyo-ku, Tokyo, 113-8510 (Japan); Ito, Kazuki; Takata, Masaki [Structural Materials Science Laboratory, RIKEN SPring-8 Center, Sayo, Hyogo 679-5148 (Japan); Kobayashi, Toshihide, E-mail: htakahas@chem-bio.gunma-u.ac.j [Lipid Biology Laboratory, RIKEN, Wako, Saitama 351-0198 (Japan)

2010-10-01

Cardiolipin (CL) is a membrane phospholipid containing four fatty acid chains. CL plays an important role in energy transformation in mitochondria. The disorder of CL biosynthesis is involved in a genetic disease, Barth syndrome. Alteration of fatty acid composition of CLs has been found in Barth syndrome patients, i.e., the decrease of unsaturated fatty acid chains. In this study, we investigated how the degree of saturation alters the structure of CL bilayers by using X-ray scattering. Bovine heart CL and two synthetic CLs were compared. Fatty acid compositions of these three CLs have different saturation. Small-angle X-ray scattering data showed that the decrease of the number of double bonds in the unsaturated fatty acid chains causes to thicken the CL bilayers. In addition, wide-angle X-ray scattering data suggested that the decrease reduces the degree of disorder of the hydrophobic region in a liquid crystalline phase. These results may be related to the dysfunction of mitochondria in Barth syndrome.

Diffuse x-ray scattering study of interfacial structure of self-assembled conjugated polymers

International Nuclear Information System (INIS)

Wang Jun; Park, Y.J.; Lee, K.-B.; Hong, H.; Davidov, D.

2002-01-01

The interfacial structures of self-assembled heterostructures through alternate deposition of conjugated and nonconjugated polymers were studied by x-ray reflectivity and nonspecular scattering. We found that the interfacial width including the effects of both interdiffusion and interfacial roughness (correlated) was mainly contributed by the latter one. The self-assembled deposition induced very small interdiffusion between layers. The lateral correlation length ξ parallel grew as a function of deposition time (or film thickness) described by a power law ξ parallel ∝t β/H and was also observed from the off-specular scattering

Design and Tests of the Hard X-ray Polarimeter X-Calibur

Directory of Open Access Journals (Sweden)

M. Beilicke

2014-12-01

Full Text Available X-ray polarimetry promises to give qualitatively new information bout high-energy astrophysical sources, such as binary black hole  systems, micro-quasars, active galactic nuclei, and gamma-ray bursts. We designed, built and tested ahard X-ray polarimeter, X-Calibur, to be used in the focal plane of the InFOCuS grazing incidence hard X-ray telescope.X-Calibur combines a low-Z Compton scatterer with a CZT detector assembly to measure the polarization of 20−60 keV X-rays making use of the fact that polarized photons Compton scatter preferentially perpendicular to the electric field orientation; in principal, a similar space-borne experiment could be operated in the 5−100 keV regime. X-Calibur achieves a high detection efficiency of order unity.

LabVIEW-based X-ray detection system for laser compton scattering experiment

International Nuclear Information System (INIS)

Luo Wen; Xu Wang; Pan Qiangyan

2010-01-01

A LabVIEW-based X-ray detection system has been developed for laser-Compton scattering (LCS) experiment at the 100 MeV Linac of the Shanghai Institute of Applied Physics (SINAP). It mainly consists of a Si (Li) detector, readout electronics and a LabVIEW-based Data Acquisition (DAQ), and possesses the functions of signal spectrum displaying, acquisition control and simple online data analysis and so on. The performance test shows that energy and time resolutions of the system are 184 eV at 5.9 keV and ≤ 1% respectively and system instability is found to be 0.3‰ within a week. As a result, this X-ray detection system has low-cost and high-performance features and can meet the requirements of LCS experiment. (authors)

More accurate X-ray scattering data of deeply supercooled bulk liquid water

Energy Technology Data Exchange (ETDEWEB)

Neuefeind, Joerg C [ORNL; Benmore, Chris J [Argonne National Laboratory (ANL); Weber, Richard [Argonne National Laboratory (ANL); Paschek, Dietmar [Rostock University, Rostock, Germany

2011-01-01

Deeply supercooled water droplets held container-less in an acoustic levitator are investigated with high energy X-ray scattering. The temperature dependence X-ray structure function is found to be non-linear. Comparison with two popular computer models reveals that structural changes are predicted too abrupt by the TIP5P model, while the rate of change predicted by TIP4P is in much better agreement with experiment. The abrupt structural changes predicted by the TIP5P model to occur in the temperature range between 260-240K as water approaches the homogeneous nucleation limit are unrealistic. Both models underestimate the distance between neighbouring oxygen atoms and overestimate the sharpness of the OO distance distribution, indicating that the strength of the H-bond is overestimated in these models.

Influence of multiple scattering of a relativistic electron in a periodic layered medium on coherent X-ray radiation

Energy Technology Data Exchange (ETDEWEB)

Blazhevich, S. V.; Kos’kova, T. V.; Noskov, A. V., E-mail: noskovbupk@mail.ru [Belgorod State National Research University (Russian Federation)

2016-01-15

A dynamic theory of coherent X-ray radiation generated in a periodic layered medium by a relativistic electron multiply scattered by target atoms has been developed. The expressions describing the spectral–angular characteristics of parametric X-ray radiation and diffracted transition radiation are derived. Numerical calculations based on the derived expressions have been performed.

PAL-XFEL soft X-ray scientific instruments and X-ray optics: First commissioning results

Science.gov (United States)

Park, Sang Han; Kim, Minseok; Min, Changi-Ki; Eom, Intae; Nam, Inhyuk; Lee, Heung-Soo; Kang, Heung-Sik; Kim, Hyeong-Do; Jang, Ho Young; Kim, Seonghan; Hwang, Sun-min; Park, Gi-Soo; Park, Jaehun; Koo, Tae-Yeong; Kwon, Soonnam

2018-05-01

We report an overview of soft X-ray scientific instruments and X-ray optics at the free electron laser (FEL) of the Pohang Accelerator Laboratory, with selected first-commissioning results. The FEL exhibited a pulse energy of 200 μJ/pulse, a pulse width of power of 10 500 was achieved. The estimated total time resolution between optical laser and X-ray pulses was <270 fs. A resonant inelastic X-ray scattering spectrometer was set up; its commissioning results are also reported.

Investigation of nanoscale structures by small-angle X-ray scattering in a radiochromic dosimeter

DEFF Research Database (Denmark)

Skyt, Peter Sandegaard; Jensen, Grethe Vestergaard; Wahlstedt, Isak Hannes

2014-01-01

This study examines the nanoscale structures in a radiochromic dosimeter that was based on leuco-malachite-green dye and the surfactant sodium dodecyl sulfate (SDS) suspended in a gelatin matrix. Small-angle X-ray scattering was used to investigate the structures of a range of compositions...

Surface x-ray scattering and scanning tunneling microscopy studies at the Au(111) electrode

International Nuclear Information System (INIS)

Ocko, B.M.; Magnussen, O.M.; Wang, J.X.; Adzic, R.R.

1993-01-01

This chapter reviews Surface X-ray Scattering and Scanning Tunneling Microscopy results carried out at the Au(111) surface under electrochemical conditions. Results are presented for the reconstructed surface, and for bromide and thallium monolayers. These examples are used to illustrate the complementary nature of the techniques

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

International Nuclear Information System (INIS)

Monaco, G.

2008-01-01

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

Comparison of X-ray and neutron small-angle scattering from an Al-Zn alloy

International Nuclear Information System (INIS)

Gerold, V.; Epperson, J.E.; Gerstenberg, K.W.

1978-01-01

The normalized integrated small-angle scattered intensity for Al-Zn alloys should be independent of whether the measurements are made with X-rays or neutrons. In order to check this, and thus the correction and standardization processes, the small-angle scattering from an Al-5.05 at.% Zn alloy containing GP zones was measured with these two types of radiation. The data were corrected and converted to absolute units with reference to the commonly accepted secondary standards: vanadium for the neutron data and polyethylene (Lupolen) for the X-ray data. The results are shown to differ by, at best, 6% if reasonable values for the change in atomic volume with alloy composition are taken into account. These findings are compared with those available from the literature, and the consistency is found to be somewhat lacking. Additional careful work is clearly needed to determine if the difficulty is traceable to the data correction or to the conversion to absolute units. (Auth.)

The scattering problem in X-ray adsorptiometry using an MWPC; and its solution

International Nuclear Information System (INIS)

Bateman, J.E.

1978-03-01

It is shown that a large aperture imaging X-ray absorptiometric system (in this case a xenon filled MWPC) suffers very badly from scattering in the water bath and soft tissue components of the imaged system in the bone mass measuring case. Applications of a fine focused collimator provides a satisfactory solution to the problem. (author)

Investigation of polydisperse, disordered, and fractal systems by small-angle x-ray and neutron scattering

International Nuclear Information System (INIS)

Schmidt, P.W.; Tang, Y.; Roell, A.; Steiner, M.; Hoehr, A.; Neumann, H.B.

1990-01-01

Small-angle x-ray and neutron scattering are useful methods for investigating the structure of materials on a scale from about 10 to 2000 A. Some experimental procedures and methods of data analysis for small-angle scattering are outlined, and the use of small-angle scattering for studies of polydisperse systems (i.e., systems of particles of different size) of independently scattering particles is reviewed. Some general properties of the small-angle scattering from mass and surface fractals are discussed, and some applications of these concepts in recent experimental studies are presented. Results obtained in calculations of the small-angle scattering from a model of a surface are summarized. (author) 3 figs., 18 refs

Effects of Interstellar Dust Scattering on the X-ray Eclipses of the LMXB AX J1745.6-2901 in the Galactic Center

Science.gov (United States)

Jin, Chichuan; Ponti, Gabriele; Haberl, Frank; Smith, Randall; Valencic, Lynne

2018-04-01

AX J1745.6-2901 is an eclipsing low mass X-ray binary (LMXB) in the Galactic Centre (GC). It shows significant X-ray excess emission during the eclipse phase, and its eclipse light curve shows an asymmetric shape. We use archival XMM-Newton and Chandra observations to study the origin of these peculiar X-ray eclipsing phenomena. We find that the shape of the observed X-ray eclipse light curves depends on both photon energy and the shape of the source extraction region, and also shows differences between the two instruments. By performing detailed simulations for the time-dependent X-ray dust scattering halo, as well as directly modelling the observed eclipse and non-eclipse halo profiles of AX J1745.6-2901, we obtained solid evidence that its peculiar eclipse phenomena are indeed caused by the X-ray dust scattering in multiple foreground dust layers along the line-of-sight (LOS). The apparent dependence on the instruments is caused by different instrumental point-spread-functions. Our results can be used to assess the influence of dust scattering in other eclipsing X-ray sources, and raise the importance of considering the timing effects of dust scattering halo when studying the variability of other X-ray sources in the GC, such as Sgr A⋆. Moreover, our study of halo eclipse reinforces the existence of a dust layer local to AX J1745.6-2901 as reported by Jin et al. (2017), as well as identifying another dust layer within a few hundred parsecs to Earth, containing up to several tens of percent LOS dust, which is likely to be associated with the molecular clouds in the Solar neighbourhood. The remaining LOS dust is likely to be associated with the molecular clouds located in the Galactic disk in-between.

Magnetic hysteresis of an artificial square ice studied by in-plane Bragg x-ray resonant magnetic scattering

Directory of Open Access Journals (Sweden)

J. P. Morgan

2012-06-01

Full Text Available We report X-ray resonant magnetic scattering studies of a Permalloy artificial square ice nanomagnet array, focussing on the field-driven evolution of the sum Σ and difference Δ signals of left and right handed circularly polarized synchrotron X-rays at different lateral positions in reciprocal space Qx. We used X-rays tuned to the Fe L3 resonance energy, with the scattering plane aligned along a principal symmetry axis of the array. Details of the specular Δ hysteresis curve are discussed, following the system magnetization from an initial demagnetized state. The periodic structure gives rise to distinct peaks at in-plane reciprocal Bragg positions, as shown by fitting Σ(Qx to a model based on a simple unit cell structure. Diffraction order-dependent hysteresis in Δ is observed, indicative of the reordering of magnetization on the system's two interpenetrating sublattices, which markedly deviates from an ideal Ising picture under strong applied fields.

Small-angle x-ray scattering in amorphous silicon: A computational study

Science.gov (United States)

Paudel, Durga; Atta-Fynn, Raymond; Drabold, David A.; Elliott, Stephen R.; Biswas, Parthapratim

2018-05-01

We present a computational study of small-angle x-ray scattering (SAXS) in amorphous silicon (a -Si) with particular emphasis on the morphology and microstructure of voids. The relationship between the scattering intensity in SAXS and the three-dimensional structure of nanoscale inhomogeneities or voids is addressed by generating large high-quality a -Si networks with 0.1%-0.3% volume concentration of voids, as observed in experiments using SAXS and positron annihilation spectroscopy. A systematic study of the variation of the scattering intensity in the small-angle scattering region with the size, shape, number density, and the spatial distribution of the voids in the networks is presented. Our results suggest that the scattering intensity in the small-angle region is particularly sensitive to the size and the total volume fraction of the voids, but the effect of the geometry or shape of the voids is less pronounced in the intensity profiles. A comparison of the average size of the voids obtained from the simulated values of the intensity, using the Guinier approximation and Kratky plots, with that of the same from the spatial distribution of the atoms in the vicinity of void surfaces is presented.

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

Energy Technology Data Exchange (ETDEWEB)

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

2015-08-15

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

Inelastic x-ray scattering from polycrystalline materials

International Nuclear Information System (INIS)

Fischer, I.

2008-09-01

Inelastic X-ray scattering (IXS) is a tool to determine the phonon dispersion along high symmetry directions in single crystals. However, novel materials and crystals under extreme conditions are often only available in form of polycrystalline samples. Thus the investigation is limited to orientation-averaged properties. To overcome these limitations, a methodology to extract the single crystal phonon dispersion from polycrystalline materials was developed. The approach consists of recording IXS spectra over a large momentum transfer region and confront them with a Born - von Karman model calculation. A least-square refinement of the model IXS spectra then provides the single crystal dispersion scheme. In this work the method is developed on the test case Be. Further studies were performed on more and more complex systems, in order to explore the limitations. This novel application of IXS promises to be a valuable tool in cases where single crystalline materials are not available. (author)

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

Energy Technology Data Exchange (ETDEWEB)

Braicovich, L., E-mail: lucio.braicovich@polimi.it; Minola, M.; Dellea, G.; Ghiringhelli, G. [CNR-SPIN and Dipartimento di Fisica, Politecnico di Milano, piazza Leonardo Da Vinci 32, Milano I-20133 (Italy); Le Tacon, M. [Max-Planck-Institut für Festkörperforschung, Heisenbergstrasse 1, D-70569 Stuttgart (Germany); Moretti Sala, M.; Morawe, C.; Peffen, J.-Ch.; Yakhou, F.; Brookes, N. B. [European Synchrotron Radiation Facility, 71 Avenue des Martyrs, Grenoble F-38043 (France); Supruangnet, R. [Synchrotron Light Research Institute, Nakhon Ratchasima (Thailand)

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%.

 X-RAYING THE DARK SIDE OF VENUS—SCATTER FROM VENUS’ MAGNETOTAIL?

Energy Technology Data Exchange (ETDEWEB)

Afshari, M.; Peres, G.; Petralia, A.; Reale, F. [Dipartimento di Fisica e Chimica, Università di Palermo, Piazza del Parlamento 1, I-90134 (Italy); Jibben, P. R.; Weber, M., E-mail: peres@astropa.unipa.it [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)

2016-10-01

We analyze significant X-ray, EUV, and UV emission coming from the dark side of Venus observed with Hinode /XRT and Solar Dynamics Observatory /Atmospheric Imaging Assembly ( SDO /AIA) during a transit across the solar disk that occurred in 2012. As a check we have analyzed an analogous Mercury transit that occurred in 2006. We have used the latest version of the Hinode /XRT point spread function to deconvolve Venus and Mercury X-ray images, to remove instrumental scattering. After deconvolution, the flux from Venus’ shadow remains significant while that of Mercury becomes negligible. Since stray light contamination affects the XRT Ti-poly filter data we use, we performed the same analysis with XRT Al-mesh filter data, not affected by the light leak. Even the latter data show residual flux. We have also found significant EUV (304 Å, 193 Å, 335 Å) and UV (1700 Å) flux in Venus’ shadow, measured with SDO /AIA. The EUV emission from Venus’ dark side is reduced, but still significant, when deconvolution is applied. The light curves of the average flux of the shadow in the X-ray, EUV, and UV bands appear different as Venus crosses the solar disk, but in any of them the flux is, at any time, approximately proportional to the average flux in a ring surrounding Venus, and therefore proportional to that of the solar regions around Venus’ obscuring disk line of sight. The proportionality factor depends on the band. This phenomenon has no clear origin; we suggest that it may be due to scatter occurring in the very long magnetotail of Venus.

Gamma detector for use with luggage X-ray systems

International Nuclear Information System (INIS)

McHugh, H.; Quam, W.

1998-01-01

A new gamma radiation sensor has been designed for installation on several types of luggage x-ray machines and mobile x-ray vans operated by the U.S. Customs Service and the U.S. Department of State. The use of gamma detectors on x-ray machines imposed difficulties not usually encountered in the design of gamma detectors because the spectrum of scattered x-rays, which varied from machine to machine, extended to energies significantly higher than those of the low-energy isotopic emissions. In the original design, the lower level discriminator was raised above the x-ray end point energy resulting in the loss of the americium line associated with plutonium. This reduced the overall sensitivity to unshielded plutonium by a factor of approximately 100. An improved method was subsequently developed wherein collimation was utilized in conjunction with a variable counting threshold to permit accommodation of differing conditions of x-ray scattering. This design has been shown to eliminate most of the problems due to x-ray scattering while still capturing the americium emissions. The overall sensitivity has remained quite high, though varying slightly from one model of x-ray machine to another, depending upon the x-ray scattering characteristics of each model. (author)

Small-angle X-ray scattering studies on the X-ray induced aggregation of ribonnuclease, lactate dehydrogenase, glyceraldehyde-3-phosphate dehydrogenase and serum albumin. A comparison with malate synthase

International Nuclear Information System (INIS)

Zipper, P.; Gatterer, H.G.; Schutz, J.; Durchschlag, H.

1980-01-01

The X-ray induced aggregation of ribonuclease, lactate dehydrogenase (LDH), glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and serum albumin in aqueous solution was monitored in situ by means of small-angle X-ray scattering. Measurements carried out with ribonuclease, LDH and serum albumin in the absence of dithiothreitol (DTT) and with GAPDH in the presence of 0.2mM DTT established the following series for the rates of aggregation of the proteins under these conditions: ribonuclease >LDH> >GAPDH> serum albumin. Within six hours from the beginning of irradiation (i.e. about the time required for the exposure of one complete scattering curve under the conditions of our experiments) the following increases of R tilde resulted: ribonuclease 9%, LDH 7%, GAPDH 4%, serum albumin <1%. Changes of R tilde exceeding 1% are, of course, too high to be tolerated in conventional scattering experiments. Measurements carried out with LDH and GAPDH in the presence of 2mM DTT established a strong protective effect of DTT against the X-ray induced aggregation of these enzymes. The initial increase of R tilde upon irradiation of LDH and GAPDH in the presence of 2mM DTT was found to be even lower than the increase of R tilde observed when serum albumin was irradiated in the absence of DTT. However, the observed decrease of anti x of LDH and GAPDH at the early stages of irradiation suggested the occurrence of fragmentation of the enzymes as another consequence of radiation damage. This finding is discussed in context with the results from previous scattering experiments and electrophoretic studies on malate synthase. (author)

X-ray and neutron small-angle scattering studies of human serum lipoproteins

International Nuclear Information System (INIS)

Luzzati, V.; Tardieu, A.; Mateu, L.; Sardet, C.; Stuhrmann, H.B.; Aggerbeck, L.; Scanu, A.M.

1976-01-01

The paper describes an extended x-ray study of two types of human serum lipoproteins and a neutron study of one of them. The results are similar and to some extent complementary. Serum lipoproteins provide an excellent illustration of the wealth of information that can be obtained by a small-angle scattering approach to the structure of particles with non-uniform density distribution, by using solvents of variable density

Effects of phosphonium-based ionic liquids on phospholipid membranes studied by small-angle X-ray scattering

Czech Academy of Sciences Publication Activity Database

Kontro, I.; Svedström, K.; Duša, Filip; Ahvenainen, P.; Ruokonen, S. K.; Witos, J.; Wiedmer, S. K.

2016-01-01

Roč. 201, DEC (2016), s. 59-66 ISSN 0009-3084 Institutional support: RVO:68081715 Keywords : phospholipids * x-ray scattering Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 3.361, year: 2016

In-situ real-time x-ray scattering for probing the processing-structure-performance relation

KAUST Repository

Smilgies, Detlef-M.

2014-01-01

© 2014 Materials Research Society. In-situ X-ray scattering methodology is discussed, in order to analyze the microstructure development of soft functional materials during coating, annealing, and drying processes in real-time. The relevance of a fundamental understanding of coating processes for future industrial production is pointed out.

Determination of line profiles on nano-structured surfaces using EUV and x-ray scattering

Science.gov (United States)

Soltwisch, Victor; Wernecke, Jan; Haase, Anton; Probst, Jürgen; Schoengen, Max; Krumrey, Michael; Scholze, Frank; Pomplun, Jan; Burger, Sven

2014-09-01

Non-imaging techniques like X-ray scattering are supposed to play an important role in the further development of CD metrology for the semiconductor industry. Grazing Incidence Small Angle X-ray Scattering (GISAXS) provides directly assessable information on structure roughness and long-range periodic perturbations. The disadvantage of the method is the large footprint of the X-ray beam on the sample due to the extremely shallow angle of incidence. This can be overcome by using wavelengths in the extreme ultraviolet (EUV) spectral range, EUV small angle scattering (EUVSAS), which allows for much steeper angles of incidence but preserves the range of momentum transfer that can be observed. Generally, the potentially higher momentum transfer at shorter wavelengths is counterbalanced by decreasing diffraction efficiency. This results in a practical limit of about 10 nm pitch for which it is possible to observe at least the +/- 1st diffraction orders with reasonable efficiency. At the Physikalisch-Technische Bundesanstalt (PTB), the available photon energy range extends from 50 eV up to 10 keV at two adjacent beamlines. PTB commissioned a new versatile Ellipso-Scatterometer which is capable of measuring 6" square substrates in a clean, hydrocarbon-free environment with full flexibility regarding the direction of the incident light polarization. The reconstruction of line profiles using a geometrical model with six free parameters, based on a finite element method (FEM) Maxwell solver and a particle swarm based least-squares optimization yielded consistent results for EUV-SAS and GISAXS. In this contribution we present scatterometry data for line gratings and consistent reconstruction results of the line geometry for EUV-SAS and GISAXS.