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Journal of Synchrotron Radiation

Ulrike Boesenberg, Christopher G Ryan, Robin Kirkham, D Peter Siddons, Matthias Alfeld, Jan Garrevoet, Teresa Núñez, Thorsten Claussen, Thorsten Kracht, Gerald Falkenberg
The high brilliance of third-generation synchrotron sources increases the demand for faster detectors to utilize the available flux. The Maia detector is an advanced imaging scheme for energy-dispersive detection realising dwell times per image-pixel as low as 50 µs and count rates higher than 10 × 10(6) s(-1). In this article the integration of such a Maia detector in the Microprobe setup of beamline P06 at the storage ring PETRA III at the Deutsches Elektronen-Synchrotron (DESY) in Hamburg, Germany, is described...
November 1, 2016: Journal of Synchrotron Radiation
F A Lima, M E Saleta, R J S Pagliuca, M A Eleotério, R D Reis, J Fonseca Júnior, B Meyer, E M Bittar, N M Souza-Neto, E Granado
The majority of the beamlines at the Brazilian Synchrotron Light Source Laboratory (LNLS) use radiation produced in the storage-ring bending magnets and are therefore currently limited in the flux that can be used in the harder part of the X-ray spectrum (above ∼10 keV). A 4 T superconducting multipolar wiggler (SCW) was recently installed at LNLS in order to improve the photon flux above 10 keV and fulfill the demands set by the materials science community. A new multi-purpose beamline was then installed at the LNLS using the SCW as a photon source...
November 1, 2016: Journal of Synchrotron Radiation
Alessandra Gianoncelli, George Kourousias, Lucia Merolle, Matteo Altissimo, Anna Bianco
The current status of the TwinMic beamline at Elettra synchrotron light source, that hosts the European twin X-ray microscopy station, is reported. The X-ray source, provided by a short hybrid undulator with source size and divergence intermediate between bending magnets and conventional undulators, is energy-tailored using a collimated plane-grating monochromator. The TwinMic spectromicroscopy experimental station combines scanning and full-field imaging in a single instrument, with contrast modes such as absorption, differential phase, interference and darkfield...
November 1, 2016: Journal of Synchrotron Radiation
Ashwini Kumar Poswal, Ankur Agrawal, Himanshu Kumar Poswal, Dibyendu Bhattacharyya, Shambhu Nath Jha, Naba Kishore Sahoo
An innovative scheme to carry out continuous-scan X-ray absorption spectroscopy (XAS) measurements similar to quick-EXAFS mode at the Energy-Scanning EXAFS beamline BL-09 at INDUS-2 synchrotron source (Indore, India), which is generally operated in step-by-step scanning mode, is presented. The continuous XAS mode has been implemented by adopting a continuous-scan scheme of the double-crystal monochromator and on-the-fly measurement of incident and transmitted intensities. This enabled a high signal-to-noise ratio to be maintained and the acquisition time was reduced to a few seconds from tens of minutes or hours...
November 1, 2016: Journal of Synchrotron Radiation
Alessandro Barla, Josep Nicolás, Daniele Cocco, Secundino Manuel Valvidares, Javier Herrero-Martín, Pierluigi Gargiani, Jairo Moldes, Claude Ruget, Eric Pellegrin, Salvador Ferrer
The optical design of the BOREAS beamline operating at the ALBA synchrotron radiation facility is described. BOREAS is dedicated to resonant X-ray absorption and scattering experiments using soft X-rays, in an unusually extended photon energy range from 80 to above 4000 eV, and with full polarization control. Its optical scheme includes a fixed-included-angle, variable-line-spacing grating monochromator and a pair of refocusing mirrors, equipped with benders, in a Kirkpatrick-Baez arrangement. It is equipped with two end-stations, one for X-ray magnetic circular dichroism and the other for resonant magnetic scattering...
November 1, 2016: Journal of Synchrotron Radiation
A M G Carvalho, D H C Araújo, H F Canova, C B Rodella, D H Barrett, S L Cuffini, R N Costa, R S Nunes
Various upgrades have been completed at the XRD1 beamline at the Brazilian synchrotron light source (LNLS). The upgrades are comprehensive, with changes to both hardware and software, now allowing users of the beamline to conduct X-ray powder diffraction experiments with faster data acquisition times and improved quality. The main beamline parameters and the results obtained for different standards are presented, showing the beamline ability of performing high-quality experiments in transmission geometry. XRD1 operates in the 5...
November 1, 2016: Journal of Synchrotron Radiation
Mercedes Martinson, Dean Chapman
It has been established that for cylindrically bent crystals the optimal beam characteristics occur when the geometric and single-ray foci are matched. In the beam-expanding monochromator developed for the BioMedical Imaging and Therapy beamlines at the Canadian Light Source, it was unclear how critical this `magic condition' was for preserving the transverse coherence of the beam. A study was conducted to determine whether misalignments away from the ideal conditions would severely affect the transverse coherence of the beam, thereby limiting phase-based imaging techniques...
November 1, 2016: Journal of Synchrotron Radiation
Ian Robinson, Yang Yang, Fucai Zhang, Christophe Lynch, Mohammed Yusuf, Peter Cloetens
Scanning X-ray fluorescence microscopy has been used to probe the distribution of S, P and Fe within cell nuclei. Nuclei, which may have originated at different phases of the cell cycle, are found to show very different levels of Fe present with a strongly inhomogeneous distribution. P and S signals, presumably from DNA and associated nucleosomes, are high and relatively uniform across all the nuclei; these agree with X-ray phase contrast projection microscopy images of the same samples. Possible reasons for the Fe incorporation are discussed...
November 1, 2016: Journal of Synchrotron Radiation
Keiichi Hirano, Yumiko Takahashi, Kazuyuki Hyodo, Masao Kimura
X-ray analyzer-based phase-contrast imaging is combined with computed laminography for imaging regions of interest in laterally extended flat specimens of weak absorption contrast. The optics discussed here consist of an asymmetrically cut collimator crystal and a symmetrically cut analyzer crystal arranged in a nondispersive (+, -) diffraction geometry. A generalized algorithm is given for calculating multi-contrast (absorption, refraction and phase contrast) images of a sample. Basic formulae are also presented for laminographic reconstruction...
November 1, 2016: Journal of Synchrotron Radiation
N Gueninchault, H Proudhon, W Ludwig
Multi-modal characterization of polycrystalline materials by combined use of three-dimensional (3D) X-ray diffraction and imaging techniques may be considered as the 3D equivalent of surface studies in the electron microscope combining diffraction and other imaging modalities. Since acquisition times at synchrotron sources are nowadays compatible with four-dimensional (time lapse) studies, suitable mechanical testing devices are needed which enable switching between these different imaging modalities over the course of a mechanical test...
November 1, 2016: Journal of Synchrotron Radiation
Sebastian Cartier, Matias Kagias, Anna Bergamaschi, Zhentian Wang, Roberto Dinapoli, Aldo Mozzanica, Marco Ramilli, Bernd Schmitt, Martin Brückner, Erik Fröjdh, Dominic Greiffenberg, Davit Mayilyan, Davide Mezza, Sophie Redford, Christian Ruder, Lukas Schädler, Xintian Shi, Dhanya Thattil, Gemma Tinti, Jiaguo Zhang, Marco Stampanoni
MÖNCH is a 25 µm-pitch charge-integrating detector aimed at exploring the limits of current hybrid silicon detector technology. The small pixel size makes it ideal for high-resolution imaging. With an electronic noise of about 110 eV r.m.s., it opens new perspectives for many synchrotron applications where currently the detector is the limiting factor, e.g. inelastic X-ray scattering, Laue diffraction and soft X-ray or high-resolution color imaging. Due to the small pixel pitch, the charge cloud generated by absorbed X-rays is shared between neighboring pixels for most of the photons...
November 1, 2016: Journal of Synchrotron Radiation
Valeriy Titarenko
Ring artefacts are the most disturbing artefacts when reconstructed volumes are segmented. A lot of effort has already been put into better X-ray optics, scintillators and detectors in order to minimize the appearance of these artefacts. However, additional processing is often required after standard flat-field correction. Several methods exist to suppress artefacts. One group of methods is based on minimization of the Tikhonov functional. An analytical formula for processing of a single sinogram was developed...
November 1, 2016: Journal of Synchrotron Radiation
Malte Ogurreck, Jefferson J do Rosario, Elisabeth W Leib, Daniel Laipple, Imke Greving, Felix Marschall, Arndt Last, Gerold A Schneider, Tobias Vossmeyer, Horst Weller, Felix Beckmann, Martin Müller
Photonic glass is a material class that can be used as photonic broadband reflectors, for example in the infrared regime as thermal barrier coating films. Photonic properties such as the reflectivity depend on the ordering and material packing fraction over the complete film thickness of up to 100 µm. Nanotomography allows acquiring these key parameters throughout the sample volume at the required resolution in a non-destructive way. By performing a nanotomography measurement at the PETRA III beamline P05 on a photonic glass film, the packing fraction throughout the complete sample thickness was analyzed...
November 1, 2016: Journal of Synchrotron Radiation
Ondřej Šipr, Jiří Vackář, Alexei Kuzmin
Polarization-dependent damping of the fine structure in the Cu K-edge spectrum of creatinium tetrachlorocuprate [(creat)2CuCl4] in the X-ray absorption near-edge structure (XANES) region is shown to be due to atomic vibrations. These vibrations can be separated into two groups, depending on whether the respective atoms belong to the same molecular block; individual molecular blocks can be treated as semi-rigid entities while the mutual positions of these blocks are subject to large mean relative displacements...
November 1, 2016: Journal of Synchrotron Radiation
V N Rai, Parasmani Rajput, S N Jha, D Bhattacharyya, B N Raja Shekhar, U P Deshpande, T Shripathi
X-ray absorption near-edge structure (XANES) and X-ray photoelectron spectroscopy (XPS) of Nd-doped phosphate glasses have been studied before and after gamma irradiation. The intensity and the location of the white line peak of the L3-edge XANES of Nd are found to be dependent on the ratio O/Nd in the glass matrix. Gamma irradiation changes the elemental concentration of atoms in the glass matrix, which affects the peak intensity of the white line due to changes in the covalence of the chemical bonds with Nd atoms in the glass (structural changes)...
November 1, 2016: Journal of Synchrotron Radiation
Alexander Britz, Tadesse A Assefa, Andreas Galler, Wojciech Gawelda, Michael Diez, Peter Zalden, Dmitry Khakhulin, Bruno Fernandes, Patrick Gessler, Hamed Sotoudi Namin, Andreas Beckmann, Manuel Harder, Hasan Yavaş, Christian Bressler
The technical implementation of a multi-MHz data acquisition scheme for laser-X-ray pump-probe experiments with pulse limited temporal resolution (100 ps) is presented. Such techniques are very attractive to benefit from the high-repetition rates of X-ray pulses delivered from advanced synchrotron radiation sources. Exploiting a synchronized 3.9 MHz laser excitation source, experiments in 60-bunch mode (7.8 MHz) at beamline P01 of the PETRA III storage ring are performed. Hereby molecular systems in liquid solutions are excited by the pulsed laser source and the total X-ray fluorescence yield (TFY) from the sample is recorded using silicon avalanche photodiode detectors (APDs)...
November 1, 2016: Journal of Synchrotron Radiation
Raphael Urbani, Fabian Westermeier, Benjamin Banusch, Michael Sprung, Thomas Pfohl
Combining microfluidics with coherent X-ray illumination offers the possibility to not only measure the structure but also the dynamics of flowing samples in a single-scattering experiment. Here, the power of this combination is demonstrated by studying the advective and Brownian dynamics of colloidal suspensions in microflow of different geometries. Using an experimental setup with a fast two-dimensional detector and performing X-ray correlation spectroscopy by calculating two-dimensional maps of the intensity auto-correlation functions, it was possible to evaluate the sample structure and furthermore to characterize the detailed flow behavior, including flow geometry, main flow directions, advective flow velocities and diffusive dynamics...
November 1, 2016: Journal of Synchrotron Radiation
C Leclere, T W Cornelius, Z Ren, O Robach, J S Micha, A Davydok, O Ulrich, G Richter, O Thomas
A mapping technique has been developed where a sub-micrometer focused polychromatic X-ray beam is scanned across a stationary sample instead of scanning the sample in front of the X-ray microbeam. This method is applied to a gold nanowire during its mechanical loading using the tip of an atomic force microscope. During the loading process, such a sample is `accelero-phobic', i.e. the sample scanning stages must not to be moved to avoid parasitic additional load. Without beam scanning, only one single position within the sample can be probed during the test...
November 1, 2016: Journal of Synchrotron Radiation
Christoph Schwanke, Lifei Xi, Kathrin Maria Lange
A new cell for operando soft X-ray absorption spectroscopy in transmission mode is presented. Developed for investigations on solar water-splitting catalysts, the cell allows the study of solid films in direct contact with electrolyte solution while applying voltage and visible light. The design is optimized for fast sample exchange and the simultaneous measurement of fluorescence and transmission signal. The capability of the cell is presented on a manganese oxide (MnOx) film, where electronic structure changes are monitored during forward and backward potential changes...
November 1, 2016: Journal of Synchrotron Radiation
Michael Behr, James Rix, Brian Landes, Bryan Barton, Gerry Billovits, Eric Hukkanen, Jasson Patton, Weijun Wang, Denis Keane, Steven Weigand
A new high-temperature fibre tensile cell is described, developed for use at the Advanced Photon Source at Argonne National Laboratory to enable the investigation of the carbonization and graphitization processes during carbon fibre production. This cell is used to heat precursor fibre bundles to temperatures up to ∼2300°C in a controlled inert atmosphere, while applying tensile stress to facilitate formation of highly oriented graphitic microstructure; evolution of the microstructure as a function of temperature and time during the carbonization and higher-temperature graphitization processes can then be monitored by collecting real-time wide-angle X-ray diffraction (WAXD) patterns...
November 1, 2016: Journal of Synchrotron Radiation
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