X-ray optics for advanced ultrafast pump – probe X-ray experiments at SACLA
X-ray optics were implemented for advanced ultrafast X-ray experiments with different techniques at the hard X-ray beamline BL3 of SPring-8 Å ngstrom Compact free-electron LAser. A double channel-cut crystal monochromator (DCCM) and compound refractive lenses (CRLs) were installed to tailor the beam conditions. These X-ray optics can work simultaneously with an arrival-timing monitor that compensates for timing jitter and drift. Inner-walls of channel-cut crystals (CCs) in the DCCM were processed by plasma chemical vaporization machining to remove crystallographic damage. Four-bounced reflection profiles of the CCs w...
Source: Journal of Synchrotron Radiation - February 22, 2019 Category: Physics Authors: Katayama, T. Hirano, T. Morioka, Y. Sano, Y. Osaka, T. Owada, S. Togashi, T. Yabashi, M. Tags: X-ray free electron laser X-ray optics pump – probe X-ray measurements research papers Source Type: research

Standing wave approach in the theory of X-ray magnetic reflectivity
An extension of the exact X-ray resonant magnetic reflectivity theory has been developed, taking into account the small value of the magnetic terms in the X-ray susceptibility tensor. It is shown that squared standing waves (fourth power of the total electric field) determine the output of the magnetic addition to the total reflectivity from a magnetic multilayer. The obtained generalized kinematical approach essentially speeds up the calculation of the asymmetry ratio in the magnetic reflectivity. The developed approach easily explains the peculiarities of the angular dependence of the reflectivity with the rotated polari...
Source: Journal of Synchrotron Radiation - February 19, 2019 Category: Physics Authors: Andreeva, M.A. Baulin, R.A. Repchenko, Yu.L. Tags: X-ray standing waves ellipsometry X-ray magnetic reflectometry research papers Source Type: research

M-BLANK: a program for the fitting of X-ray fluorescence spectra
The X-ray fluorescence data from X-ray microprobe and nanoprobe measurements must be fitted to obtain reliable elemental maps. The most common approach in many fitting programs is to initially remove a per-pixel baseline. Using X-ray fluorescence data of yeast and glial cells, it is shown that per-pixel baselines can result in significant, systematic errors in quantitation and that significantly improved data can be obtained by calculating an average blank spectrum and subtracting this from each pixel. (Source: Journal of Synchrotron Radiation)
Source: Journal of Synchrotron Radiation - February 19, 2019 Category: Physics Authors: Crawford, A.M. Deb, A. Penner-Hahn, J.E. Tags: X-ray fluorescence per-pixel baselines X-ray microprobes elemental maps X-ray nanoprobes research papers Source Type: research

Pump – probe laser system at the FXE and SPB/SFX instruments of the European X-ray Free-Electron Laser Facility
User operation at the European X-ray Free-Electron Laser Facility started at the SASE1 undulator beamline in fall 2017. The majority of the experiments utilize optical lasers (mostly ultrafast) for pump – probe-type measurements in combination with X-ray pulses. This manuscript describes the purpose-developed pump – probe laser system as installed at SASE1, implemented features and plans for further upgrades. (Source: Journal of Synchrotron Radiation)
Source: Journal of Synchrotron Radiation - February 15, 2019 Category: Physics Authors: Palmer, G. Kellert, M. Wang, J. Emons, M. Wegner, U. Kane, D. Pallas, F. Jezynski, T. Venkatesan, S. Rompotis, D. Brambrink, E. Monoszlai, B. Jiang, M. Meier, J. Kruse, K. Pergament, M. Lederer, M.J. Tags: ultrafast lasers burst-mode laser X-ray FEL research papers Source Type: research

The validity of an experiment testing the influence of acceleration on time dilation using a rotating M ö ssbauer absorber and a Synchrotron M ö ssbauer Source
Three experiments are reviewed, performed (in 2014 – 2016) at ID18 of ESRF to measure the influence of acceleration on time dilation by measuring the relative shift between the absorption lines of two states of the same rotating absorber with accelerations anti-parallel and parallel to the incident beam. Statistically significant data for rotation frequencies up to 510   Hz in both directions of rotation were collected. For each run with high rotation, a stable statistically significant `vibration-free' relative shift between the absorption lines of the two states was measured. This may indicate the influence of ac...
Source: Journal of Synchrotron Radiation - February 15, 2019 Category: Physics Authors: Friedman, Y. Steiner, J.M. Livshitz, S. Perez, E. Nowik, I. Felner, I. Wille, H.-C. Wortmann, G. Efrati, O. Finkelstein, A. Petitgirard, S. Chumakov, A.I. Bessas, D. Tags: time dilation ö ssbauer spectrum synchrotron radiation nuclear lighthouse effect relative shift research papers Source Type: research

Zone plates for angle-resolved photoelectron spectroscopy providing sub-micrometre resolution in the extreme ultraviolet regime
This article reports on the fabrication and testing of dedicated Fresnel zone plates for use at the nano-ARPES branch of the I05-ARPES beamline of Diamond Light Source to perform angle-resolved photoelectron spectroscopy with sub-micrometre resolution in real space. The aim of the design was to provide high photon flux combined with sub-micrometre spot sizes. The focusing lenses were tested with respect to efficiency and spatial resolution in the extreme ultraviolet between 50   eV and 90   eV. The experimentally determined diffraction efficiencies of the zone plates are as high as 8.6% at 80   eV, and a real-space r...
Source: Journal of Synchrotron Radiation - February 15, 2019 Category: Physics Authors: R ö sner, B. Dudin, P. Bosgra, J. Hoesch, M. David, C. Tags: angle-resolved photoelectron spectroscopy (ARPES) Fresnel zone plates microspectroscopy nanofocus research papers Source Type: research

Distinguishing nitrogen-containing sites in SiO2/4H-SiC(0001) after nitric oxide annealing by X-ray absorption spectroscopy
The atomic structure of nitrogen at the SiO2/4H-SiC(0001) interface has been investigated using X-ray absorption spectroscopy (XAS) in two nitric oxide annealed samples, one of which was oxidized in dry O2 (NO-POA) prior to the experiment. The peak shapes and energies of the observed and simulated spectra are in agreement and indicate that the N-containing sites could be the substitutional C site at the interface for the NO-annealed sample and the interstitial site in the interior of SiC for the NO – POA-annealed sample. XAS analysis distinguished between the N-containing sites at the SiO2/SiC interface. (Source: Jou...
Source: Journal of Synchrotron Radiation - February 15, 2019 Category: Physics Authors: Isomura, N. Kutsuki, K. Kataoka, K. Watanabe, Y. Kimoto, Y. Tags: X-ray absorption spectroscopy XAS X-ray absorption fine structure XAFS SiC – MOS interface structure research papers Source Type: research

CT dosimetry at the Australian Synchrotron for 25 – 100   keV photons and 35 – 160   mm-diameter biological specimens
The dose length product (DLP) method for medical computed tomography (CT) dosimetry is applied on the Australian Synchrotron Imaging and Medical Beamline (IMBL). Beam quality is assessed from copper transmission measurements using image receptors, finding near 100% (20   keV), 3.3% (25   keV) and 0.5% (30 – 40   keV) relative contributions from third-harmonic radiation. The flat-panel-array medical image receptor is found to have a non-linear dose response curve. The amount of radiation delivered during an axial CT scan is measured as the dose in air alone, and inside cylindrical PMMA phantoms with diameters 35...
Source: Journal of Synchrotron Radiation - February 15, 2019 Category: Physics Authors: Midgley, S. Schleich, N. Merchant, A. Stevenson, A. Tags: Australian Synchrotron Imaging and Medical Beamline third harmonic CT dosimetry CT dose indices CT dose length product effective dose research papers Source Type: research

Fast beam monitor diamond-based devices for VUV and X-ray synchrotron radiation applications
The improved performance of third-generation light sources and the advent of next-generation synchrotron radiation facilities require the use of extremely precise monitoring of the main photon-beam parameters, such as position, absolute and relative intensity, and temporal structure. These parameters, and associated real-time feedbacks, are fundamental at the beamline control level and at the machine control level, to improve the stability of the photon beams and to provide bunch-to-bunch quantitative information. Fast response time, high radiation hardness and visible – blind response are main features of photon-bea...
Source: Journal of Synchrotron Radiation - February 13, 2019 Category: Physics Authors: Di Fraia, M. De Sio, A. Antonelli, M. Nesti, R. Panella, D. Menk, R.H. Cautero, G. Coreno, M. Catone, D. Zema, N. Callegari, C. Pace, E. Tags: CVD diamond synchrotron instrumentation beam monitor detectors research papers Source Type: research

Reactions of Rh2(CH3COO)4 with thiols and thiolates: a structural study
The structural differences between the aerobic reaction products of Rh2(AcO)4 (1; AcO − = CH3COO − ) with thiols and thiolates in non-aqueous media are probed by X-ray absorption spectroscopy. For this study, ethanethiol, dihydrolipoic acid (DHLA; a dithiol) and their sodium thiolate salts were used. Coordination of simple thiols to the axial positions of Rh2(AcO)4 with Rh — SH bonds of 2.5 – 2.6   Å keeps the RhII — RhII bond intact (2.41 ± 0.02   Å ) but leads to a colour change from emerald green to burgundy. Time-dependent density functional theory (TD-DFT) calculati...
Source: Journal of Synchrotron Radiation - February 13, 2019 Category: Physics Authors: Enriquez Garcia, A. Jalilehvand, F. Niksirat, P. Tags: dirhodium(II) tetraacetate thiol thiolate structure EXAFS UV – vis TD-DFT research papers Source Type: research

A microfluidic flow-focusing device for low sample consumption serial synchrotron crystallography experiments in liquid flow
This article presents a fast and optimized manufacturing route to metal – polyimide microfluidic flow-focusing devices which allow for the collection of X-ray diffraction data in flow. The flow-focusing conditions allow for sample consumption to be significantly decreased, while also opening up the possibility of more complex experiments such as rapid mixing for time-resolved serial crystallography. This high-repetition-rate experiment allows for full datasets to be obtained quickly ( ∼ 1   h) from crystal slurries in liquid flow. The X-ray compatible microfluidic chips are easily manufacturable, reliable and d...
Source: Journal of Synchrotron Radiation - February 13, 2019 Category: Physics Authors: Monteiro, D.C.F. Vakili, M. Harich, J. Sztucki, M. Meier, S.M. Horrell, S. Josts, I. Trebbin, M. Tags: serial synchrotron crystallography microfluidics flow focusing research papers Source Type: research

SyLMAND: a microfabrication beamline with wide spectral and beam power tuning range at the Canadian Light Source
SyLMAND, the Synchrotron Laboratory for Micro and Nano Devices, is a recently commissioned microfabrication bend magnet beamline with ancillary cleanroom facilities at the Canadian Light Source. The synchrotron radiation is applied to pattern high-aspect-ratio polymer microstructures used in the area of micro-electro-mechanical systems (MEMS). SyLMAND particularly focuses on spectral and beam power adjustability and large exposable area formats in an inert gas atmosphere; a rotating-disk intensity chopper allows for independent beam-power reduction, while continuous spectral tuning between 1 – 2   keV and>15  ...
Source: Journal of Synchrotron Radiation - February 12, 2019 Category: Physics Authors: Wells, G. Achenbach, S. Subramanian, V. Jacobs, M. Klymyshyn, D. Iyer, S. Moazed, B. Hanson, J. Shen, C. Haluzan, D. Tags: X-ray lithography beamlines microfabrication MEMS Source Type: research

Application of interference fits on cylindrical monochromator crystals to overcome clamping and cooling deformations
In order to provide adequate cryogenic cooling of both existing and next-generation crystal monochromators, a new approach to produce an optimum thermal interface between the first crystal and its copper heat exchanger is proposed. This will ensure that the increased heat load deposited by higher X-ray powers can be properly dissipated. Utilizing a cylindrical silicon crystal, a tubular copper heat exchanger and by exploiting the differing thermal and mechanical properties of the two, a very good thermal interface was achieved at liquid-nitrogen temperatures. The surface flatness of the diffracting plane at one end of the ...
Source: Journal of Synchrotron Radiation - February 12, 2019 Category: Physics Authors: Stimson, J. Ward, M. Sutter, J. Diaz-Moreno, S. Alcock, S. Docker, P. Tags: monochromator design interference fit first crystal cooling research papers Source Type: research

First results from the XMCD facility at the Energy-Dispersive EXAFS beamline of the Indus-2 synchrotron source
Setting up of the X-ray Magnetic Circular Dichroism (XMCD) measurement facility with hard X-rays at the Energy-Dispersive EXAFS beamline (BL-08) at the Indus-2 synchrotron source is reported. This includes the design and development of a water-cooled electromagnet having a highest magnetic field of 2   T in a good field volume of 125   mm3 and having a 10   mm hole throughout for passage of the synchrotron beam. This also includes the development of an (X – Z – θ ) motion stage for the heavy electromagnet for aligning its axis and the beam hole along the synchrotron beam direction. Along with the ab...
Source: Journal of Synchrotron Radiation - February 12, 2019 Category: Physics Authors: Patra, N. Sachan, U.G.P.S. SundarRajan, S. Malhotra, S. Harad, V. Agarwal, A. Divedi, A. Jha, S.N. Bhattacharyya, D. Tags: XMCD EXAFS beamline Indus-2 synchrotron radiation research papers Source Type: research

Data management and processing workflow for the Materials Physics and Engineering group beamlines at the Advanced Photon Source
The ability to store, organize, process and distribute experimental data effectively, efficiently and securely is particularly important for large user facilities like the Advanced Photon Source. In this article, the deployment of the APS Data Management System (DM) at the 1-ID and 6-BM beamlines of the APS is described. These two beamlines support a wide range of experimental techniques and generate data at relatively high rates, making them ideal candidates to illustrate the deployment and customization of the DM system and its tools. Using several usage examples at these beamlines, various capabilities of the DM system ...
Source: Journal of Synchrotron Radiation - February 12, 2019 Category: Physics Authors: Park, J.-S. Horn, C. Ramanathan, P. Kenesei, P. Veseli, S. Tags: data management data processing workflow research papers Source Type: research

Measurement of the absolute number of photons of the hard X-ray beamline at the Linac Coherent Light Source
X-ray free-electron lasers provide intense pulses of coherent X-rays with a short pulse duration. These sources are chaotic by nature and therefore, to be used at their full potential, require that every X-ray pulse is characterized in terms of various relevant properties such as intensity, photon energy, position and timing. Diagnostics are for example installed on an X-ray beamline to specifically monitor the intensity of individual X-ray pulses. To date, these can however only provide a single-shot value of the relative number of photons per shot. Here are reported measurements made in January 2015 of the absolute numbe...
Source: Journal of Synchrotron Radiation - February 11, 2019 Category: Physics Authors: Song, S. Alonso-Mori, R. Chollet, M. Feng, Y. Glownia, J.M. Lemke, H.T. Sikorski, M. Zhu, D. Moeller, S. Lee, H.J. Hunter, M.S. Carini, G. Tiedtke, K. Jastrow, U. Sorokin, A. Richter, M. Owada, S. Tono, K. Saito, N. Tanaka, T. Kato, M. Yabashi, M. Robert, Tags: FEL hard X-rays absolute intensity research papers Source Type: research

Post-reconstruction 3D single-distance phase retrieval for multi-stage phase-contrast tomography with photon-counting detectors
This article presents a modified computational protocol where a post-reconstruction 3D volume phase retrieval is applied. By comparing the conventional 2D and the proposed 3D reconstructions of a large mastectomy specimen (9   cm in diameter and 3   cm in height), it is here shown that the 3D approach compensates for the multi-stage artifacts, it avoids refined projection stitching, and the image quality in terms of spatial resolution, contrast and contrast-to-noise ratio is preserved. (Source: Journal of Synchrotron Radiation)
Source: Journal of Synchrotron Radiation - February 11, 2019 Category: Physics Authors: Brun, F. Brombal, L. Di Trapani, V. Delogu, P. Donato, S. Dreossi, D. Rigon, L. Longo, R. Tags: X-ray phase contrast computed tomography single-distance phase retrieval photon-counting detectors image artifacts research papers Source Type: research

Proposal for a photoelectron spectroscopy and microscopy beamline (0.5 – 11   keV) at the High Energy Photon Source
An optical design study of a beamline proposed for the new 6   GeV synchrotron, the High Energy Photon Source (HEPS), to be built in Beijing, China, is described. The beamline is designed to cover an energy range from 0.5 to 11   keV with two experimental stations, one for X-ray photoelectron spectroscopy (PES) experiments and the other for photoelectron emission microscopy (XPEEM) experiments. A 5   m APPLE   II-type undulator with a relatively long magnetic period (55   mm) is used as the only radiation source. To optimize the optical efficiency for the full energy range, the beamline is split into a soft X-ray...
Source: Journal of Synchrotron Radiation - February 7, 2019 Category: Physics Authors: Tang, K. Zheng, L. Wang, J. Zhao, Y. Tags: PES/HAXPES PEEM/HAXPEEM beamline X-ray optics beamlines Source Type: research

The LISA beamline at ESRF
This contribution provides a description of LISA, the new Italian Collaborating Research Group beamline operative at the European Synchrotron Radiation Facility. A presentation of the instruments available and optical devices is given as well as the main X-ray parameters (flux, energy resolution, focal spot dimensions, etc.) and comparison with theoretical calculations. The beamline has been open to users since April 2018 and will be ready at the opening of the Extremely Brilliant Source in late-2020. (Source: Journal of Synchrotron Radiation)
Source: Journal of Synchrotron Radiation - February 7, 2019 Category: Physics Authors: d'Acapito, F. Lepore, G.O. Puri, A. Laloni, A. La Manna, F. Dettona, E. De Luisa, A. Martin, A. Tags: X-ray absorption spectroscopy synchrotron radiation instrumentation beamlines LISA beamline Source Type: research

Design and performance of bending-magnet beamline BL02B at the SSRF
The BL02B bending-magnet beamline at the Shanghai Synchrotron Radiation Facility (SSRF) has been constructed and is now operational for ambient-pressure photoelectron spectroscopy (APPES) and photon-in/photon-out spectroscopy (PIPOS) experimental use. Optical optimization was implemented for realization of high performance, e.g. photon flux, energy-resolving power and focus spot size. X-ray photoelectron spectroscopy experiments show that the energy range extends from 40 to 2000   eV. Argon, nitrogen and neon gas core-shell excitation spectra indicate energy-resolving powers of over 1.4 × 104 @ 244   eV, 1.0 &tim...
Source: Journal of Synchrotron Radiation - February 7, 2019 Category: Physics Authors: Meng, X. Guo, Z. Wang, Y. Zhang, H. Han, Y. Zhao, G. Liu, Z. Tai, R. Tags: bending-magnet source photon flux energy-resolving power spot size beamlines Source Type: research

First operation of the SASE1 undulator system of the European X-ray Free-Electron Laser
The European XFEL comprises three undulator systems. All of the systems use standardized mechanical, magnetic and control components. The key elements such as undulators, phase shifters and quadrupole movers as well as their controls are described, with special emphasis on the SASE1 undulator system, which was the first to become operational and has been lasing since May 2017. The role of these systems for the commissioning is outlined with special emphasis on beam-based alignment, which was important to achieve first lasing. Radiation damage was observed. The exposure doses were measured with the online radiation dosimetr...
Source: Journal of Synchrotron Radiation - February 7, 2019 Category: Physics Authors: Abeghyan, S. Bagha-Shanjani, M. Chen, G. Englisch, U. Karabekyan, S. Li, Y. Preisskorn, F. Wolff-Fabris, F. Wuenschel, M. Yakopov, M. Pflueger, J. Tags: undulator systems beam-based alignment radiation damage phase shifters quadrupole movers high-duty-cycle machines research papers Source Type: research

The U125 insertion device beamline at the Metrology Light Source
At the Metrology Light Source, an electron storage ring dedicated to metrological applications, the U125 insertion device beamline utilizes undulator radiation for various applications over a broad spectral range. Using a hybrid normal-incidence and grazing-incidence in-vacuum switchable plane-grating monochromator, a spectral region ranging from the near-infrared to soft X-ray is covered. The beamline is dedicated to surface-analytical methods, e.g. ellipsometry, photoelectron spectroscopy or photoemission tomography. The traceability of radiometric quantities, i.e. quantitative determination of the available radiant powe...
Source: Journal of Synchrotron Radiation - February 6, 2019 Category: Physics Authors: Gottwald, A. Kaser, H. Kolbe, M. Tags: undulator beamline extreme ultraviolet radiometry spectral purity beamlines Source Type: research

Deep X-ray lithography system with a uniform and high-accuracy fabrication area established in beamline BL11 at NewSUBARU
A new lithography system to fabricate high-aspect-ratio 3D microstructures was developed at the NewSUBARU synchrotron radiation facility (University of Hyogo, Japan). The X-ray beam generated by this system has high parallelism (horizontal and vertical divergence angles of 278   µ rad and 14   µ rad, respectively) and high photon flux (31   mW   mm − 2 at a beam current of 300   mA). The high photon flux and exposure area of the system were validated and a beam-scan method for a large exposure area with a uniform dose distribution has been proposed. In addition, the deep X-ray lithography perfor...
Source: Journal of Synchrotron Radiation - February 6, 2019 Category: Physics Authors: Takeuchi, M. Yamaguchi, A. Utsumi, Y. Tags: deep X-ray lithography microfabrication LIGA process beamlines Source Type: research

Generation of ultrashort coherent radiation based on a laser plasma accelerator
A laser plasma accelerator (LPA) has the potential to realize compact free-electron laser (FEL) radiation at the regular laboratory scale. However, large initial angular divergence and energy spread dramatically hinder ways to transport the beam and realize FEL radiation. Although methods have been proposed to solve these problems, the relatively large jitter, including transverse position jitter and energy jitter, still limits the advance of these experiments. In this paper a simple method to realize coherent harmonic generation based on a LPA beam is proposed. The scheme is very compact, adopting a high-power laser split...
Source: Journal of Synchrotron Radiation - February 6, 2019 Category: Physics Authors: Liu, T. Feng, C. Xiang, D. Liu, J. Wang, D. Tags: laser plasma accelerator coherent harmonic generation free-electron lasers research papers Source Type: research

In situ synchrotron research of phase formation in mechanically activated 3Ti   +   Al powder composition during high-temperature synthesis under the condition of heating with high-frequency electromagnetic fields
An in situ synchrotron study of the specific features of the phase formation dynamics in mechanically activated 16   wt% Al   +   Ti powder composition is described, the high-temperature synthesis being carried out under the condition of high volume inflammation by means of inductive heating. The kinetics of the phase formation were registered with an experimental complex, especially designed, constructed and adjusted for the method of dynamic diffraction analysis in synchrotron radiation beams. It has been experimentally in situ shown that increasing the time of mechanical activation of the initial powder mixture re...
Source: Journal of Synchrotron Radiation - January 25, 2019 Category: Physics Authors: Loginova, M. Sobachkin, A. Sitnikov, A. Yakovlev, V. Filimonov, V. Myasnikov, A. Sharafutdinov, M. Tolochko, B. Tags: mechanically activated treatment high-temperature synthesis experimental complex inductive heating dynamics of phase formation X-ray diffractometry powder composition titanium aluminide research papers Source Type: research

Fast positioning for X-ray scanning microscopy by a combined motion of sample and beam-defining optics
Scanning X-ray microscopy such as X-ray ptychography requires accurate and fast positioning of samples in the X-ray beam. Sample stages often have a high mobile mass as they may carry additional mechanics or mirrors for position measurements. The high mobile mass of a piezo stage can introduce vibrations in the setup that will lead to imaging quality deterioration. Sample stages also require a large travel range which results in a slow positioning step response and thus high positioning overhead. Moving lightweight X-ray optics, such as focusing Fresnel zone plates, instead of the sample can improve the situation but it ma...
Source: Journal of Synchrotron Radiation - January 25, 2019 Category: Physics Authors: Odstrcil, M. Lebugle, M. Lachat, T. Raabe, J. Holler, M. Tags: ptychography X-ray imaging Fresnel zone plate research papers Source Type: research

Development of a crystal collimation system for high-resolution ultra-small-angle X-ray scattering applications
Crystal collimation offers a viable alternative to the commonly used pinhole collimation in small-angle X-ray scattering (SAXS) for specific applications requiring highest angular resolution. This scheme is not affected by the parasitic scattering and diffraction-limited beam broadening. The Darwin width of the rocking curve of the crystals mainly defines the ultimate beam divergence. For this purpose, a dispersive Si-111 crystal collimation set-up based on two well conditioned pseudo channel-cut crystals (pairs of well polished, independent parallel crystals) using a higher-order reflection (Si-333) has been developed. Th...
Source: Journal of Synchrotron Radiation - January 25, 2019 Category: Physics Authors: Sztucki, M. Leonardon, J. Van Vaerenbergh, P. Gorini, J. Boesecke, P. Narayanan, T. Tags: USAXS high-resolution SAXS crystal collimation pseudo channel-cut crystals research papers Source Type: research

Oriented Gaussian beams for high-accuracy computation with accuracy control of X-ray propagation through a multi-lens system
A highly accurate method for calculating X-ray propagation is developed. Within this approach, the propagating wave is represented as a superposition of oriented Gaussian beams. The direction of wave propagation in each Gaussian beam agrees with the local direction of propagation of the X-ray wavefront. When calculating the propagation of X-ray waves through lenses, the thin lens approximation is applied. In this approximation, the wave parameters change discontinuously when the wave passes through a lens; the corresponding explicit formulae are derived. The theory is applied to highly accurate calculation of the focusing ...
Source: Journal of Synchrotron Radiation - January 21, 2019 Category: Physics Authors: Wojda, P. Kshevetskii, S. Tags: X-ray wave X-ray optics X-ray propagation Helmholtz equation Gaussian beams wave propagation direction lens focusing control of calculation accuracy diffraction research papers Source Type: research

Scanning transmission X-ray microscopy with efficient X-ray fluorescence detection (STXM-XRF) for biomedical applications in the soft and tender energy range
Scanning transmission X-ray microscopy, especially in combination with X-ray fluorescence detection (STXM-XRF) in the soft X-ray energy range, is becoming an increasingly important tool for life sciences. Using X-ray fluorescence detection, the study of biochemical mechanisms becomes accessible. As biological matrices generally have a low fluorescence yield and thus a low fluorescence signal, high detector efficiency (e.g. large solid angle) is indispensable for avoiding long measurement times and radiation damage. Here, the new AnImaX STXM-XRF microscope equipped with a large solid angle of detection enabling fast scans a...
Source: Journal of Synchrotron Radiation - January 21, 2019 Category: Physics Authors: L ü hl, L. Andrianov, K. Dierks, H. Haidl, A. Dehlinger, A. Heine, M. Heeren, J. Nisius, T. Wilhein, T. Kanngie ß er, B. Tags: X-ray microscopy X-ray fluorescence biomedical applications research papers Source Type: research

Deducing density and strength of nanocrystalline Ta and diamond under extreme conditions from X-ray diffraction
In situ X-ray diffraction with advanced X-ray sources offers unique opportunities for investigating materials properties under extreme conditions such as shock-wave loading. Here, Singh's theory for deducing high-pressure density and strength from two-dimensional (2D) diffraction patterns is rigorously examined with large-scale molecular dynamics simulations of isothermal compression and shock-wave compression. Two representative solids are explored: nanocrystalline Ta and diamond. Analysis of simulated 2D X-ray diffraction patterns is compared against direct molecular dynamics simulation results. Singh's method is highly ...
Source: Journal of Synchrotron Radiation - January 21, 2019 Category: Physics Authors: Zhang, Y.Y. Tang, M.X. Cai, Y. E, J.C. Luo, S.N. Tags: high-pressure density and strength nanocrystalline Ta diamond diamond anvil cell compression shock compression X-ray diffraction simulation molecular dynamics research papers Source Type: research

Phenomenological and numerical analysis of power evolution and bunching in single-pass X-ray FELs
The harmonic power and bunching evolution in X-ray single-pass free-electron lasers (FELs) is modelled and the harmonic generation in a phase-shifted two-frequency FEL is explored. The advanced phenomenological FEL model, which is validated numerically and experimentally, is employed. The model accounts for major losses for each harmonic individually; it is compared with reported experimental data and with PERSEO numerical simulations, which are performed here for a variety of experiments. The latter cover the radiation wavelength range 0.15 – 300   nm. The phenomenological description is based on a few key FEL par...
Source: Journal of Synchrotron Radiation - November 15, 2018 Category: Physics Authors: Zhukovsky, K. Kalitenko, A. Tags: undulator radiation two-frequency undulator harmonic generation free-electron laser research papers Source Type: research

In situ high-temperature EXAFS measurements on radioactive and air-sensitive molten salt materials
The development at the Delft University of Technology (TU Delft, The Netherlands) of an experimental set-up dedicated to high-temperature in situ EXAFS measurements of radioactive, air-sensitive and corrosive fluoride salts is reported. A detailed description of the sample containment cell, of the furnace design, and of the measurement geometry allowing simultaneous transmission and fluorescence measurements is given herein. The performance of the equipment is tested with the room-temperature measurement of thorium tetrafluoride, and the Th — F and Th — Th bond distances obtained by fitting of the EXAFS data ar...
Source: Journal of Synchrotron Radiation - November 1, 2018 Category: Physics Authors: Smith, A.L. Verleg, M.N. Vlieland, J. Haas, D. de Ocadiz-Flores, J.A. Martin, P. Rothe, J. Dardenne, K. Salanne, M. Gheribi, A.E. Capelli, E. van Eijck, L. Konings, R.J.M. Tags: XAFS fluoride salts molten salt reactor neutron diffraction molecular dynamics research papers Source Type: research

One-dimensional parallax-free position-sensitive detector for diffraction measurements based on a home-made thin THGEM
A large parallax-free gas diffraction meter based on a thinner-THGEM (thick gaseous electron multiplier) has been developed at the Beijing Synchrotron Radiation Facility (BSRF). A thinner-THGEM of thickness 200   µ m is adopted, which can be shaped into a curve to eliminate parallax-error effects. The detector is designed to have a 48 ° open angle positioned 20   cm from the powder samples. A front-end electronics board with 128   channels direct-current mode was adapted for the 8   keV BSRF beamline with 0.2   ns/100   ns stable duty cycle. Two powder samples, TiO2 and SnO2, were tested separately. T...
Source: Journal of Synchrotron Radiation - November 1, 2018 Category: Physics Authors: Chen, S. Liu, H. Liu, Q. Zheng, Y. Wang, B. Huang, W. Dong, Y. Rong, Y. Jiao, X. Guan, Y. Wang, J. Li, M. Liu, J. Zhang, M. Tags: micropattern gaseous detectors thinner-THGEM X-ray diffraction BSRF research papers Source Type: research

COMET: a new end-station at SOLEIL for coherent magnetic scattering in transmission
A new instrument named COMET for COherent Magnetic scattering Experiments in Transmission using polarized soft X-rays has been designed and built. This high-vacuum setup is placed at the intermediate focal point of the elastic branch of the SEXTANTS beamline at Synchrotron SOLEIL. The main application is in solid state physics, the instrument being optimized for studying material properties using coherent scattering of soft X-rays with an emphasis on imaging, with chemical selectivity, the magnetic domains of artificially nano-structured materials. The instrument's principal features are presented and illustrated through r...
Source: Journal of Synchrotron Radiation - November 1, 2018 Category: Physics Authors: Popescu, H. Perron, J. Pilette, B. Vacheresse, R. Pinty, V. Gaudemer, R. Sacchi, M. Delaunay, R. Fortuna, F. Medjoubi, K. Desjardins, K. Luning, J. Jaouen, N. Tags: coherent diffraction imaging soft X-rays holography ptychography magnetic materials beamlines Source Type: research

Numerical analysis of brilliance and coherent photon flux of segmented undulator radiation based on statistical optics
A method based on wave optics together with electron tracking is used to analyze synchrotron radiation from a segmented undulator in a double or multi mini- β function lattice storage ring. Radiation brilliance and transverse coherence features are investigated, where the former is calculated with the Wigner distribution function and the latter is evaluated by integrating the photon flux and cross-spectral density to exhibit the coherent flux and overall degree of coherence. To be specific, radiation properties for a single undulator in a typically single mini- β function and a tandem undulator in a double mini- ...
Source: Journal of Synchrotron Radiation - November 1, 2018 Category: Physics Authors: Luo, H.-W. Chung, T.-Y. Lee, C.-H. Hwang, C.-S. Tags: Wigner distribution function brilliance transverse coherence double mini- β y lattice segment undulator research papers Source Type: research

Silicon carbide X-ray beam position monitors for synchrotron applications
In this work, the performance of thin silicon carbide membranes as material for radiation hard X-ray beam position monitors (XBPMs) is investigated. Thermal and electrical behavior of XBPMs made from thin silicon carbide membranes and single-crystal diamond is compared using finite-element simulations. Fabricated silicon carbide devices are also compared with a 12   µ m commercial polycrystalline diamond XBPM at the Swiss Light Source at the Paul Scherrer Institute. Results show that silicon carbide devices can reach equivalent transparencies while showing improved linearity, dynamics and signal-to-noise ratio comp...
Source: Journal of Synchrotron Radiation - November 1, 2018 Category: Physics Authors: Nida, S. Tsibizov, A. Ziemann, T. Woerle, J. Moesch, A. Schulze-Briese, C. Pradervand, C. Tudisco, S. Sigg, H. Bunk, O. Grossner, U. Camarda, M. Tags: beam position monitors silicon carbide radiation detector beamline instrumentation X-rays research papers Source Type: research

Single-image phase retrieval for hard X-ray grating interferometry
A single-image method is proposed for quantitative phase retrieval in hard X-ray grating interferometry. This novel method assumes a quasi-homogeneous sample, with a constant ratio between the real and imaginary parts of its complex refractive index. The method is first theoretically derived and presented, and then validated by synchrotron radiation experiments. Compared with the phase-stepping method, the presented approach abandons grating scanning and multiple image acquisition, and is therefore advantageous in terms of its simplified acquisition procedure and reduced data-collection times, which are especially importan...
Source: Journal of Synchrotron Radiation - November 1, 2018 Category: Physics Authors: Wang, Z. Ren, K. Shi, X. Ren, Y. Gao, K. Wu, Z. Tags: X-ray imaging phase-contrast imaging grating interferometry phase retrieval research papers Source Type: research

Alignment of the aberration-free XUV Raman spectrometer at FLASH
An extreme-ultraviolet (XUV) double-stage Raman spectrometer is permanently installed as an experimental end-station at the PG1 beamline of the soft X-ray/XUV free-electron laser in Hamburg, FLASH. The monochromator stages are designed according to the Czerny – Turner optical scheme, adapted for the XUV photon energy range, with optical elements installed at grazing-incidence angles. Such an optical scheme along with the usage of off-axis parabolic mirrors for light collimation and focusing allows for aberration-free spectral imaging on the optical axis. Combining the two monochromators in additive dispersion mode al...
Source: Journal of Synchrotron Radiation - November 1, 2018 Category: Physics Authors: Biednov, M. Brenner, G. Dicke, B. Weigelt, H. Keitel, B. R ü bhausen, M. Dziarzhytski, S. Tags: XUV Raman spectrometer alignment interferometry free-electron laser wavefront sensor research papers Source Type: research

Methods for operando coherent X-ray diffraction of battery materials at the Advanced Photon Source
Bragg coherent X-ray diffraction imaging has become valuable for visualization of the structural, morphological and strain evolution of crystals in operando electrode materials. As the electrode material particles (either in a single-crystal form or an aggregation form of single crystals) are evenly dispersed and randomly oriented in the electrode laminate, the submicrometer-sized coherentX-ray beam can be used to probe the local properties of electrode material crystals using two approaches. Coherent multi-crystal diffraction provides collective structural information of phase transitions in tens of crystals simultaneousl...
Source: Journal of Synchrotron Radiation - November 1, 2018 Category: Physics Authors: Li, L. Xie, Y. Maxey, E. Harder, R. Tags: coherent multi-crystal diffraction Bragg coherent diffractive imaging in operando characterization of battery materials experimental protocols research papers Source Type: research

Inverse-phase composite zone plate providing deeper focus than the normal diffraction-limited depth of X-ray microbeams
A novel type of zone plate (ZP), termed an inverse-phase composite ZP, is proposed to gain a deeper focus than the standard diffraction-limited depth of focus, with little reduction in spatial resolution. The structure is a combination of an inner ZP functioning as a conventional phase ZP and an outer ZP functioning with third-order diffraction with opposite phase to the inner ZP. Two-dimensional complex amplitude distributions neighboring the focal point were calculated using a wave-optical approach of diffraction integration with a monochromatic plane-wave illumination, where one dimension is the radial direction and the...
Source: Journal of Synchrotron Radiation - November 1, 2018 Category: Physics Authors: Kagoshima, Y. Takayama, Y. Tags: zone plate diffraction limit depth of focus spatial resolution microbeam research papers Source Type: research

Automated data collection and real-time data analysis suite for serial synchrotron crystallography
At the Swiss Light Source macromolecular crystallography (MX) beamlines the collection of serial synchrotron crystallography (SSX) diffraction data is facilitated by the recent DA+ data acquisition and analysis software developments. The SSX suite allows easy, efficient and high-throughput measurements on a large number of crystals. The fast continuous diffraction-based two-dimensional grid scan method allows initial location of microcrystals. The CY+ GUI utility enables efficient assessment of a grid scan's analysis output and subsequent collection of multiple wedges of data (so-called minisets) from automatically selecte...
Source: Journal of Synchrotron Radiation - November 1, 2018 Category: Physics Authors: Basu, S. Kaminski, J.W. Panepucci, E. Huang, C.-Y. Warshamanage, R. Wang, M. Wojdyla, J.A. Tags: serial synchrotron crystallography protein crystallography online data analysis data merging data acquisition computer programs Source Type: research

X-ray diffraction reveals blunt-force loading threshold for nanoscopic structural change in ex   vivo neuronal tissues
In this study, we make use of the fact that changes in the structure and periodicity of myelin may indicate neurological damage and can be detected with X-ray diffraction (XRD). XRD allows access to a nanoscopic resolution range not readily achieved by alternative methods, nor does the experimental methodology require chemical sample fixation. In this study, XRD was used to evaluate the affects of controlled mechanical loading on myelin packing structure in ex vivo optic nerve samples. By using a series of crush tests on isolated optic nerves a quantified baseline for mechanical load was found to induce changes in the pack...
Source: Journal of Synchrotron Radiation - November 1, 2018 Category: Physics Authors: Orgel, J. Madhurapantula, R.S. Eidsmore, A. Wang, M. Dutov, P. Modrich, C.D. Antipova, O. McDonald, J. Satapathy, S. Tags: blunt-force ex vivo myelin loading X-ray diffraction research papers Source Type: research

A new diffractometer for diffuse scattering studies on the ID28 beamline at the ESRF
A new diffractometer is now available to the general user community at the ESRF. The new diffractometer is a side station of the high-resolution inelastic X-ray scattering spectrometer on beamline ID28 and is located in the same experimental hutch. Both instruments can be operated simultaneously. The new diffractometer combines a fast and low-noise hybrid pixel detector with a variable diffraction geometry. The beam spot on the sample is 50   µ m × 50   µ m, where focusing is achieved by a combination of Be lenses and a KB mirror. Wavelengths from 0.5 to 0.8   Å can be used for the diffraction...
Source: Journal of Synchrotron Radiation - November 1, 2018 Category: Physics Authors: Girard, A. Nguyen-Thanh, T. Souliou, S.M. Stekiel, M. Morgenroth, W. Paolasini, L. Minelli, A. Gambetti, D. Winkler, B. Bosak, A. Tags: X-ray diffuse scattering diffraction inelastic X-ray scattering phonons disorder beamlines Source Type: research

Ca and S K-edge XANES of CaS calculated by different methods: influence of full potential, core hole and Eu doping
Ca and S K-edge spectra of CaS are calculated by the full-potential Green's function multiple-scattering method, by the FLAPW method and by the finite-difference method. All three techniques lead to similar spectra. Some differences remain close to the edge, both when comparing different calculations with each other and when comparing the calculations with earlier experimental data. Here it is found that using the full potential does not lead to significant improvement over the atomic spheres approximation and that the effect of the core hole can be limited to the photoabsorbing atom alone. Doping CaS with Eu will not affe...
Source: Journal of Synchrotron Radiation - November 1, 2018 Category: Physics Authors: Š ipr, O. Khan, W. Joly, Y. Min á r, J. Tags: XANES CaS full potential core hole research papers Source Type: research

The influence of nitrogen doping on the electronic structure of the valence and conduction band in TiO2
X-ray emission spectroscopy (XES) and X-ray absorption spectroscopy (XAS) provide a unique opportunity to probe both the highest occupied and the lowest unoccupied states in matter with bulk sensitivity. In this work, a combination of valence-to-core XES and pre-edge XAS techniques are used to determine changes induced in the electronic structure of titanium dioxide doped with nitrogen atoms. Based on the experimental data it is shown that N-doping leads to incorporation of the p-states on the occupied electronic site. For the conduction band, a decrease in population of the lowest unoccupied d-localized orbitals with resp...
Source: Journal of Synchrotron Radiation - November 1, 2018 Category: Physics Authors: Wojtaszek, K. Wach, A. Czapla-Masztafiak, J. Tyrala, K. S á , J. Y ı ld ı z Ö zer, L. Garlisi, C. Palmisano, G. Szlachetko, J. Tags: X-ray emission spectroscopy X-ray absorption spectroscopy electronic structure analysis TiO2 doping research papers Source Type: research

A new mini-triaxial cell for combined high-pressure and high-temperature in situ synchrotron X-ray microtomography experiments up to 400 ° C and 24   MPa
A new experimental triaxial cell for in situ synchrotron X-ray micro-computed tomography aimed at imaging small samples of (6   mm × 19   mm) at high temperatures (up to 400 ° C) and pressures (up to 24   MPa confining) is presented. The system has flow-through capabilities, independent axial and radial pressure control, and has been developed and tested at the 8.3.2. beamline at the Advanced Light Source. The characteristics of this new experimental rig are described, along with the challenges, mainly concerning the combination of X-ray transparency with vessel strength at high temperature, and solutions f...
Source: Journal of Synchrotron Radiation - November 1, 2018 Category: Physics Authors: Voltolini, M. Barnard, H. Creux, P. Ajo-Franklin, J. Tags: X-ray micro-tomography high pressure and temperature in situ X-ray imaging earth sciences short communications Source Type: research

Thermal behavior of single-crystal scintillators for high-speed X-ray imaging
In this study, a transient one-dimensional numerical simulation of the temperature and stresses within three common scintillator crystals (YAG, LuAG and LSO) used for high-speed X-ray imaging is presented. Various conditions of thermal loading and convective cooling are also presented. (Source: Journal of Synchrotron Radiation)
Source: Journal of Synchrotron Radiation - November 1, 2018 Category: Physics Authors: Kastengren, A. Tags: scintillators X-ray imaging thermal behaviour research papers Source Type: research

Operando X-ray absorption spectroscopy study of the Fischer – Tropsch reaction with a Co catalyst
This article describes the setting up of a facility on the energy-scanning EXAFS beamline (BL-09) at RRCAT, Indore, India, for operando studies of structure – activity correlation during a catalytic reaction. The setup was tested by operando X-ray absorption spectroscopy (XAS) studies performed on a Co-based catalyst during the Fischer – Tropsch reaction to obtain information regarding structural changes in the catalyst during the reaction. Simultaneous gas chromatography (GC) measurements during the reaction facilitate monitoring of the product gases, which in turn gives information regarding the activity of t...
Source: Journal of Synchrotron Radiation - November 1, 2018 Category: Physics Authors: Nayak, C. Jain, P. Vinod, C.P. Jha, S.N. Bhattacharyya, D. Tags: EXAFS XANES catalysis in situ studies Fischer – Tropsch reaction structure activity correlation research papers Source Type: research

The GALAXIES inelastic hard X-ray scattering end-station at Synchrotron SOLEIL
GALAXIES is an in-vacuum undulator hard X-ray micro-focused beamline dedicated to the study of the electronic structure of materials with high energy resolution using both photoelectron spectroscopy and inelastic X-ray scattering and under both non-resonant (NR-IXS) and resonant (RIXS) conditions. Due to the penetrating power of hard X-rays and the `photon-in/photon-out' technique, the sample environment is not a limitation. Materials under extreme conditions, for example in diamond anvil cells or catalysis chambers, thus constitute a major research direction. Here, the design and performance of the inelastic X-ray scatter...
Source: Journal of Synchrotron Radiation - November 1, 2018 Category: Physics Authors: Ablett, J.M. Prieur, D. C é olin, D. Lassalle-Kaiser, B. Lebert, B. Sauvage, M. Moreno, T. Bac, S. Bal é dent, V. Ovono, A. Morand M. G é lebart, F. Shukla, A. Rueff, J.-P. Tags: GALAXIES beamline Synchrotron SOLEIL inelastic hard X-ray scattereing beamlines Source Type: research

X-ray mirror surface figure correction with nanometre precision controlled by layer stresses simulated by FEA
Hard X-rays with energies higher than several kiloelectronvolts can be focused to spot sizes below 10   nm with the present synchrotron beamlines, offering unique advantages for the chemical, elemental and structure analysis of matter. Nevertheless, a surface precision on the nanometre scale for the focusing optics is required and remains the main hurdle limiting X-ray analytical techniques with single-nanometre spatial resolution. On the other hand, to preserve the wavefront properties of coherent X-ray beams, precise control of the reflective mirror surface quality at the nanometre scale is demanded for X-ray free-elec...
Source: Journal of Synchrotron Radiation - November 1, 2018 Category: Physics Authors: Cheng, X. Zhang, L. Tags: multilayer X-ray mirror layer stress nanofocusing profile coating short communications Source Type: research