XMCD studies of magnetic polarization at Mo atoms in CoMo alloy and magnetically coupled Co/Mo multilayers
Magnetic polarization of Mo atoms in Co96Mo4 alloy film and Co/Mo multilayered structures has been studied by X-ray magnetic circular dichroism. Samples with Mo spacers of two different thicknesses (0.9 nm and 1.8 nm) were investigated. Mo atoms receive a magnetic moment of − 0.21 μ B in the alloy. In the multilayer with the thinner Mo spacer (dMo = 0.9 nm) the magnetic moment is much smaller ( − 0.03 μ B). In both cases the measured induced moment at the Mo site is oriented antiparallel to the moment at the Co atoms. The presence of the induced moment in the Mo spacer coincides with antiferro...
Source: Journal of Synchrotron Radiation - August 2, 2018 Category: Physics Authors: Wawro, A. Mili ń ska, E. Kurant, Z. Pietruczik, A. Kanak, J. Ollefs, K. Wilhelm, F. Rogalev, A. Maziewski, A. Tags: interlayer magnetic coupling induced magnetic moment magnetic multilayers X-ray magnetic circular dichroism research papers Source Type: research
Defect engineering by synchrotron radiation X-rays in CeO2 nanocrystals
This work reports an unconventional defect engineering approach using synchrotron-radiation-based X-rays on ceria nanocrystal catalysts of particle sizes 4.4 – 10.6 nm. The generation of a large number of oxygen-vacancy defects (OVDs), and therefore an effective reduction of cations, has been found in CeO2 catalytic materials bombarded by high-intensity synchrotron X-ray beams of beam size 1.5 mm × 0.5 mm, photon energies of 5.5 – 7.8 keV and photon fluxes up to 1.53 × 1012 photons s − 1. The experimentally observed cation reduction was theoretically explained b...
Source: Journal of Synchrotron Radiation - August 2, 2018 Category: Physics Authors: Wu, T.-S. Syu, L.-Y. Weng, S.-C. Jeng, H.-T. Chang, S.-L. Soo, Y.-L. Tags: X-ray irradiation defect engineering XANES DFT research papers Source Type: research
Atmospheric coherent X-ray diffraction imaging for in situ structural analysis at SPring-8 Hyogo beamline BL24XU
This article describes an atmospheric CXDI system developed at SPring-8 Hyogo beamline BL24XU for in situ structural analysis and designed for experiments at a photon energy of 8 keV. This relatively high X-ray energy enables experiments to be conducted under ambient atmospheric conditions, which is advantageous for the visualization of samples in native states. The illumination condition with pinhole-slit optics is optimized according to wave propagation calculations based on the Fresnel – Kirchhoff diffraction formula so that the sample is irradiated by X-rays with a plane wavefront and high photon flux of &sim...
Source: Journal of Synchrotron Radiation - June 29, 2018 Category: Physics Authors: Takayama, Y. Takami, Y. Fukuda, K. Miyagawa, T. Kagoshima, Y. Tags: coherent X-ray diffraction imaging non-crystalline samples structural analysis humidity control research papers Source Type: research
Third International Workshop on Improving Data Quality in XAFS Spectroscopy, Q2XAFS2017
This issue of the Journal of Synchrotron Radiation is a special issue including papers from the Q2XAFS2017 workshop. Here, a brief introduction is given. (Source: Journal of Synchrotron Radiation)
Source: Journal of Synchrotron Radiation - June 29, 2018 Category: Physics Authors: Diaz-Moreno, S. Strange, R.W. Tags: Q2XAFS2017 workshop XAFS spectroscopy improving data quality editorial Source Type: research
ID30B – a versatile beamline for macromolecular crystallography experiments at the ESRF
ID30B is an undulator-based high-intensity, energy-tuneable (6.0 – 20 keV) and variable-focus (20 – 200 µ m in diameter) macromolecular crystallography (MX) beamline at the ESRF. It was the last of the ESRF Structural Biology Group's beamlines to be constructed and commissioned as part of the ESRF's Phase I Upgrade Program and has been in user operation since June 2015. Both a modified microdiffractometer (MD2S) incorporating an in situ plate screening capability and a new flexible sample changer (the FlexHCD) were specifically developed for ID30B. Here, the authors provide the current beamline ch...
Source: Journal of Synchrotron Radiation - June 27, 2018 Category: Physics Authors: McCarthy, A.A. Barrett, R. Beteva, A. Caserotto, H. Dobias, F. Felisaz, F. Giraud, T. Guijarro, M. Janocha, R. Khadrouche, A. Lentini, M. Leonard, G.A. Lopez Marrero, M. Malbet-Monaco, S. McSweeney, S. Nurizzo, D. Papp, G. Rossi, C. Sinoir, J. Sorez, C. S Tags: ID30B MD2S REX rapid nozzle changer FlexHCD SPINEplus gripper experimental phasing automation beamlines Source Type: research
Direct information retrieval after 3D reconstruction in grating-based X-ray phase-contrast computed tomography
Grating-based X-ray differential phase-contrast imaging has attracted a great amount of attention and has been considered as a potential imaging method in clinical medicine because of its compatibility with the traditional X-ray tube source and the possibility of a large field of view. Moreover, phase-contrast computed tomography provides three-dimensional phase-contrast visualization. Generally, two-dimensional information retrieval performed on every projection is required prior to three-dimensional reconstruction in phase-contrast computed tomography. In this paper, a three-dimensional information retrieval method to se...
Source: Journal of Synchrotron Radiation - June 27, 2018 Category: Physics Authors: Wu, Z. Gao, K. Wang, Z. Wei, C. Wali, F. Zan, G. Wei, W. Zhu, P. Tian, Y. Tags: direct information retrieval method grating-based phase-contrast imaging differential phase-contrast imaging computed tomography research papers Source Type: research
A biological perspective towards a standard for information exchange and reporting in XAS
The complex structural landscape of biological samples and their sensitivity to X-ray exposure leads to specific challenges in biological X-ray absorption spectroscopy (bio-XAS) research, which in turn has necessitated standardization of various aspects of bio-XAS data measurement, analysis and interpretation. The bio-XAS community is therefore well suited for the development of a data-reporting standard with the specific aim of creating a feedback loop for improving/standardizing data analysis protocols and optionally to make published data available to collaborators/researchers in a meaningful and quantitative format. Th...
Source: Journal of Synchrotron Radiation - June 27, 2018 Category: Physics Authors: Sarangi, R. Tags: biological XAS EXAFS analysis data reporting standard research papers Source Type: research
Improving the detection efficiency and modulation transfer function of lens-coupled indirect X-ray imaging detectors based on point spread functions simulated according to lens performance parameters
Lens-coupled indirect X-ray imaging detectors have the advantage of high resolution and the disadvantage of low detection efficiency. Using thicker single-crystalline films (SCFs) can improve the detection efficiency. However, the image quality will become worse due to the degradation of the point spread function (PSF) and modulation transfer function (MTF). This disadvantage can be improved by deconvolution with the PSF, which is unknown. In this article, a method was established to acquire the PSF based on a simulation of the imaging process for a lens-coupled indirect X-ray imaging detector. Because the structural param...
Source: Journal of Synchrotron Radiation - June 26, 2018 Category: Physics Authors: Wang, Y. Li, G. Zhang, J. Yi, Q. Zhao, Y. Li, K. Zhu, Y. Jiang, X. Tags: lens-coupled indirect X-ray imaging detector detection efficiency point spread function modulation transfer function lens performance parameters research papers Source Type: research
Smaller capillaries improve the small-angle X-ray scattering signal and sample consumption for biomacromolecular solutions
Radiation damage by intense X-ray beams at modern synchrotron facilities is one of the major complications for biological small-angle X-ray scattering (SAXS) investigations of macromolecules in solution. To limit the damage, samples are typically measured under a laminar flow through a cell (typically a capillary) such that fresh solution is continuously exposed to the beam during measurement. The diameter of the capillary that optimizes the scattering-to-absorption ratio at a given X-ray wavelength can be calculated a priori based on fundamental physical properties. However, these well established scattering and absorptio...
Source: Journal of Synchrotron Radiation - June 26, 2018 Category: Physics Authors: Schroer, M.A. Blanchet, C.E. Gruzinov, A.Y. Gr ä wert, M.A. Brennich, M.E. Hajizadeh, N.R. Jeffries, C.M. Svergun, D.I. Tags: small-angle X-ray scattering protein solution radiation damage flow through sample environment research papers Source Type: research
Dual-polarity pulse processing and analysis for charge-loss correction in cadmium – zinc – telluride pixel detectors
Charge losses at the inter-pixel gap are typical drawbacks in cadmium – zinc – telluride (CZT) pixel detectors. In this work, an original technique able to correct charge losses occurring after the application of charge-sharing addition (CSA) is presented. The method, exploiting the strong relation between the energy after CSA and the beam position at the inter-pixel gap, allows the recovery of charge losses and improvements in energy resolution. Sub-millimetre CZT pixel detectors were investigated with both uncollimated radiation sources and collimated synchrotron X-rays, at energies below and above the K-shel...
Source: Journal of Synchrotron Radiation - June 26, 2018 Category: Physics Authors: Abbene, L. Gerardi, G. Principato, F. Bettelli, M. Seller, P. Veale, M.C. Fox, O. Sawhney, K. Zambelli, N. Benassi, G. Zappettini, A. Tags: X-ray and gamma-ray detectors CdZnTe detectors charge sharing charge losses energy-resolved photon-counting detectors research papers Source Type: research
Steps towards XAFS beamline automation and remote access
Although remote access to beamline synchrotron facilities is now a common operation mode at macromolecular crystallography beamlines thanks to substantial efforts in automated processes for sample preparation and handling, experiment planning and analysis, this is still not the case for XAFS beamlines. Here the experience and developments undertaken at LNLS and Diamond in automation are described, in an attempt to tackle the specific challenges posed by the high variability in experimental conditions and configurations that XAFS measurements require. (Source: Journal of Synchrotron Radiation)
Source: Journal of Synchrotron Radiation - June 26, 2018 Category: Physics Authors: Figueroa, S.J.A. Beniz, D.B. Mauricio, J.C. Piton, J.R. Parry, S.A. Cibin, G. Tags: beamline remote access beamline automation XAFS LabWeb science studio research papers Source Type: research
Elemental fingerprinting of mineral species in iron-fortified milk: anomalous small-angle X-ray scattering and resonant soft X-ray scattering studies
Anomalous small-angle X-ray scattering (ASAXS) and resonant soft X-ray scattering (RSoXS) are two related techniques that can enable element-specific structural information to be obtained. The development of iron-fortified milk products can greatly benefit from such techniques, allowing the structure of iron and other minerals (such as native calcium) within the casein micelle to be determined. Each method has advantages and disadvantages: for ASAXS, the sample preparation is straightforward, but the signal is relatively low and information about the structure of Ca is difficult to access. RSoXS can be used to study both C...
Source: Journal of Synchrotron Radiation - June 25, 2018 Category: Physics Authors: Ingham, B. Kirby, N. Wang, C. Brady, M. Carr, A. Tags: anomalous small-angle X-ray scattering resonant soft X-ray scattering milk iron fortification research papers Source Type: research
High Bragg reflectivity of diamond crystals exposed to multi-kW mm − 2 X-ray beams
X-ray free-electron lasers in the oscillator configuration (XFELO) are future fully coherent hard X-rays sources with ultrahigh spectral purity. X-ray beams circulate in an XFELO optical cavity comprising diamond single crystals. They function as high-reflectance (close to 100%), narrowband ( ∼ 10 meV) Bragg backscattering mirrors. The average power density of the X-ray beams in the XFELO cavity is predicted to be as high as ∼ 10 kW mm − 2. Therefore, XFELO feasibility relies on the ability of diamond crystals to withstand such a high radiation load and preserve their high reflectivity. Here the e...
Source: Journal of Synchrotron Radiation - June 17, 2018 Category: Physics Authors: Kolodziej, T. Shvyd'ko, Y. Shu, D. Kearney, S. Stoupin, S. Liu, W. Gog, T. Walko, D.A. Wang, J. Said, A. Roberts, T. Goetze, K. Baldini, M. Yang, W. Fister, T. Blank, V. Terentyev, S. Kim, K.-J. Tags: diamond X-ray optics radiation damage X-ray free-electron laser oscillators Bragg reflectivity research papers Source Type: research
Multiscale X-ray imaging using ptychography
The success of ptychography and other imaging experiments at third-generation X-ray sources is apparent from their increasingly widespread application and the improving quality of the images they produce both for resolution and contrast and in terms of relaxation of experimental constraints. The wider availability of highly coherent X-rays stimulates the development of several complementary techniques which have seen limited mutual integration in recent years. This paper presents a framework in which some of the established imaging techniques – with particular regard for ptychography – are flexibly applied to t...
Source: Journal of Synchrotron Radiation - June 17, 2018 Category: Physics Authors: Sala, S. Kuppili, V.S.C. Chalkidis, S. Batey, D.J. Shi, X. Rau, C. Thibault, P. Tags: ptychography X-ray imaging coherent diffraction phase contrast scanning transmission X-ray microscopy research papers Source Type: research
Absorption, refraction and scattering retrieval in X-ray analyzer-based imaging
A three-image algorithm is proposed in order to retrieve the absorption, refraction and ultra-small-angle X-ray scattering (USAXS) properties of the object in X-ray analyzer-based imaging. Based on the Gaussian fitting to the rocking curve, the novel algorithm is theoretically derived and presented, and validated by synchrotron radiation experiments. Compared with multiple-image radiography, this algorithm only requires a minimum of three intensity measurements, and is therefore advantageous in terms of simplified acquisition procedure and reduced data collection times, which are especially important for specific applicati...
Source: Journal of Synchrotron Radiation - June 17, 2018 Category: Physics Authors: Wang, Z. Liu, D. Zhang, J. Huang, W. Yuan, Q. Gao, K. Wu, Z. Tags: X-ray imaging phase contrast analyzer-based imaging information retrieval USAXS rocking curves three-image algorithms research papers Source Type: research
More are better, but the details matter: combinations of multiple Fresnel zone plates for improved resolution and efficiency in X-ray microscopy
Fresnel zone plates used for X-ray nanofocusing face high-aspect-ratio nanofabrication challenges in combining narrow transverse features (for high spatial resolution) along with extended optical modulation along the X-ray beam direction (to improve efficiency). The stacking of multiple Fresnel zone plates along the beam direction has already been shown to offer improved characteristics of resolution and efficiency when compared with thin single zone plates. Using multislice wave propagation simulation methods, here a number of new schemes for the stacking of multiple Fresnel zone plates are considered. These include consi...
Source: Journal of Synchrotron Radiation - June 17, 2018 Category: Physics Authors: Li, K. Jacobsen, C. Tags: Fresnel zone plates X-ray microscopy X-ray optics research papers Source Type: research
Fully automated beamline control system for XAS beamlines
Owing to the growing demand for complex in situ experiments, the handling of synchrotron experiments has become increasingly complicated. The control system at the XAS beamline of the Karlsruhe Institute of Technology synchrotron was automated based on a user-driven development cycle. By combining intelligent remote-controlled hardware and highly integrated software layers it is now possible to record data with a high level of reproducibility, eliminating human malperformance. The additional advantage of automation is the possibility of real 24/7 operation without tiring. This paper focuses on the options of optimization a...
Source: Journal of Synchrotron Radiation - June 17, 2018 Category: Physics Authors: Mangold, S. Tags: XAS control system automation beamline research papers Source Type: research
Distributed X-ray photon correlation spectroscopy data reduction using Hadoop MapReduce
Multi-speckle X-ray photon correlation spectroscopy (XPCS) is a powerful technique for characterizing the dynamic nature of complex materials over a range of time scales. XPCS has been successfully applied to study a wide range of systems. Recent developments in higher-frame-rate detectors, while aiding in the study of faster dynamical processes, creates large amounts of data that require parallel computational techniques to process in near real-time. Here, an implementation of the multi-tau and two-time autocorrelation algorithms using the Hadoop MapReduce framework for distributed computing is presented. The system scale...
Source: Journal of Synchrotron Radiation - June 14, 2018 Category: Physics Authors: Khan, F. Narayanan, S. Sersted, R. Schwarz, N. Sandy, A. Tags: multi-speckle X-ray photon correlation spectroscopy XPCS MapReduce parallel implementation Advanced Photon Source research papers Source Type: research
Rutile- and anatase-type temperature-dependent pre-edge peak intensities in K-edge XANES spectra for AO (A = Mn), A2O3 (A = Sc, Cr and Mn) and AO2 (A = Ti and V)
Pre-edge peaks in 3d transition-metal element (Sc, Ti, V, Cr and Mn) K-edge XANES (X-ray absorption near-edge structure) spectra in AO2 (A = Ti and V), A2O3 (A = Sc, Cr and Mn) and AO (A = Mn) are measured at various temperatures. Quantitative comparisons for the XANES spectra were investigated by using absorption intensity invariant point normalization. The energy position of the difference peak (D peak) is obtained from the difference between the low- and high-temperature XANES spectra. There are two kinds of temperature dependence for pre-edge peak intensity: rutile- and anatase-type. The true te...
Source: Journal of Synchrotron Radiation - June 14, 2018 Category: Physics Authors: Tobase, T. Yoshiasa, A. Hiratoko, T. Nakatsuka, A. Tags: transition-metal oxides pre-edge peak intensity temperature dependence phase transition XANES research papers Source Type: research
The optical stretcher as a tool for single-particle X-ray imaging and diffraction
For almost half a century, optical tweezers have successfully been used to micromanipulate micrometre and sub-micrometre-sized particles. However, in recent years it has been shown experimentally that, compared with single-beam traps, the use of two opposing and divergent laser beams can be more suitable in studying the elastic properties of biological cells and vesicles. Such a configuration is termed an optical stretcher due to its capability of applying high deforming forces on biological objects such as cells. In this article the experimental capabilities of an optical stretcher as a potential sample delivery system fo...
Source: Journal of Synchrotron Radiation - June 14, 2018 Category: Physics Authors: Nicolas, J.-D. Hagemann, J. Sprung, M. Salditt, T. Tags: X-ray diffraction X-ray phase-contrast imaging X-ray holography three-dimensional reconstruction biological cells research papers Source Type: research
Characterization of the X-ray coherence properties of an undulator beamline at the Advanced Photon Source
In anticipation of the increased use of coherent X-ray methods and the need to upgrade beamlines to match improved source quality, here the coherence properties of the X-rays delivered by beamline 12ID-D at the Advanced Photon Source have been characterized. The measured X-ray divergence, beam size, brightness and coherent flux at energies up to 26 keV are compared with the calculated values from the undulator source, and the effects of beamline optics such as a mirror, monochromator and compound refractive lenses are evaluated. Diffraction patterns from slits as a function of slit width are analyzed using wave propaga...
Source: Journal of Synchrotron Radiation - June 13, 2018 Category: Physics Authors: Ju, G. Highland, M.J. Thompson, C. Eastman, J.A. Fuoss, P.H. Zhou, H. Dejus, R. Stephenson, G.B. Tags: coherence divergence brightness research papers Source Type: research
Characterization of a submicro-X-ray fluorescence setup on the B16 beamline at Diamond Light Source
An X-ray fluorescence setup has been tested on the B16 beamline at the Diamond Light Source synchrotron with two different excitation energies (12.7 and 17 keV). This setup allows the scanning of thin samples (thicknesses up to several micrometers) with a sub-micrometer resolution (beam size of 500 nm × 600 nm determined with a 50 µ m Au wire). Sensitivities and detection limits reaching values of 249 counts s − 1 fg − 1 and 4 ag in 1000 s, respectively (for As K α excited with 17 keV), are presented in order to demonstrate the capabilities of this s...
Source: Journal of Synchrotron Radiation - June 13, 2018 Category: Physics Authors: Rauwolf, M. Turyanskaya, A. Ingerle, D. Szoboszlai, N. Pape, I. Malandain, A.W. Fox, O.J.L. Hahn, L. Sawhney, K.J.S. Streli, C. Tags: SR submicro-XRF beamline B16 elemental imaging scanning human bone cells research papers Source Type: research
SwissFEL Aramis beamline photon diagnostics
The SwissFEL Aramis beamline, covering the photon energies between 1.77 keV and 12.7 keV, features a suite of online photon diagnostics tools to help both users and FEL operators in analysing data and optimizing experimental and beamline performance. Scientists will be able to obtain information about the flux, spectrum, position, pulse length, and arrival time jitter versus the experimental laser for every photon pulse, with further information about beam shape and size available through the use of destructive screens. This manuscript is an overview of the diagnostics tools available at SwissFEL and presents their...
Source: Journal of Synchrotron Radiation - June 12, 2018 Category: Physics Authors: Jurani ć , P. Rehanek, J. Arrell, C.A. Pradervand, C. Ischebeck, R. Erny, C. Heimgartner, P. Gorgisyan, I. Thominet, V. Tiedtke, K. Sorokin, A. Follath, R. Makita, M. Seniutinas, G. David, C. Milne, C.J. Lemke, H. Radovic, M. Hauri, C.P. Patthey, L. Tags: FEL physics photon diagnostics instrumentation hard X-rays beamlines Source Type: research
X-ray phase-contrast imaging with engineered porous materials over 50 keV
X-ray phase-contrast imaging can substantially enhance image contrast for weakly absorbing samples. The fabrication of dedicated optics remains a major barrier, especially in high-energy regions (i.e. over 50 keV). Here, the authors perform X-ray phase-contrast imaging by using engineered porous materials as random absorption masks, which provides an alternative solution to extend X-ray phase-contrast imaging into previously challenging higher energy regions. The authors have measured various samples to demonstrate the feasibility of the proposed engineering materials. This technique could potentially be useful for stu...
Source: Journal of Synchrotron Radiation - June 12, 2018 Category: Physics Authors: Wang, H. Cai, B. Pankhurst, M.J. Zhou, T. Kashyap, Y. Atwood, R. Le Gall, N. Lee, P. Drakopoulos, M. Sawhney, K. Tags: X-ray phase imaging speckle technique hard X-rays random attenuation masks high-energy regions porous materials research papers Source Type: research
A compact and flexible induction furnace for in situ X-ray microradiograhy and computed microtomography at Elettra: design, characterization and first tests
A compact and versatile induction furnace for in situ high-resolution synchrotron and laboratory hard X-ray microradiography and computed microtomography is described. The furnace can operate from 773 to 1723 K. Its programmable controller enables the user to specify multiple heating and cooling ramp rates as well as variable dwell times at fixed temperatures allowing precise control of heating and cooling rates to within 5 K. The instrument can work under a controlled atmosphere. Thanks to the circular geometry of the induction coils, the heat is homogeneously distributed in the internal volume of the graphite cel...
Source: Journal of Synchrotron Radiation - June 1, 2018 Category: Physics Authors: Kudrna Pra š ek, M. Pistone, M. Baker, D.R. Sodini, N. Marinoni, N. Lanzafame, G. Mancini, L. Tags: X-ray microtomography in situ synchrotron X-ray imaging induction furnace metals volcanic rocks ceramics research papers Source Type: research
Large-area single-photon-counting CdTe detector for synchrotron radiation computed tomography: a dedicated pre-processing procedure
Large-area CdTe single-photon-counting detectors are becoming more and more attractive in view of low-dose imaging applications due to their high efficiency, low intrinsic noise and absence of a scintillating screen which affects spatial resolution. At present, however, since the dimensions of a single sensor are small (typically a few cm2), multi-module architectures are needed to obtain a large field of view. This requires coping with inter-module gaps and with close-to-edge pixels, which generally show a non-optimal behavior. Moreover, high-Z detectors often show gain variations in time due to charge trapping: this effe...
Source: Journal of Synchrotron Radiation - June 1, 2018 Category: Physics Authors: Brombal, L. Donato, S. Brun, F. Delogu, P. Fanti, V. Oliva, P. Rigon, L. Di Trapani, V. Longo, R. Golosio, B. Tags: single-photon counting CdTe pre-processing dynamic correction breast-CT research papers Source Type: research
The Spectroscopy Village at Diamond Light Source
This manuscript presents the current status and technical details of the Spectroscopy Village at Diamond Light Source. The Village is formed of four beamlines: I18, B18, I20-Scanning and I20-EDE. The village provides the UK community with local access to a hard X-ray microprobe, a quick-scanning multi-purpose XAS beamline, a high-intensity beamline for X-ray absorption spectroscopy of dilute samples and X-ray emission spectroscopy, and an energy-dispersive extended X-ray absorption fine-structure beamline. The optics of B18, I20-scanning and I20-EDE are detailed; moreover, recent developments on the four beamlines, includi...
Source: Journal of Synchrotron Radiation - June 1, 2018 Category: Physics Authors: Diaz-Moreno, S. Amboage, M. Basham, M. Boada, R. Bricknell, N.E. Cibin, G. Cobb, T.M. Filik, J. Freeman, A. Geraki, K. Gianolio, D. Hayama, S. Ignatyev, K. Keenan, L. Mikulska, I. Mosselmans, J.F.W. Mudd, J.J. Parry, S.A. Tags: X-ray absorption spectroscopy microfocus spectroscopy X-ray emission spectroscopy energy-dispersive EXAFS research papers Source Type: research
Xi-cam: a versatile interface for data visualization and analysis
Xi-cam is an extensible platform for data management, analysis and visualization. Xi-cam aims to provide a flexible and extensible approach to synchrotron data treatment as a solution to rising demands for high-volume/high-throughput processing pipelines. The core of Xi-cam is an extensible plugin-based graphical user interface platform which provides users with an interactive interface to processing algorithms. Plugins are available for SAXS/WAXS/GISAXS/GIWAXS, tomography and NEXAFS data. With Xi-cam's `advanced' mode, data processing steps are designed as a graph-based workflow, which can be executed live, locally or rem...
Source: Journal of Synchrotron Radiation - May 31, 2018 Category: Physics Authors: Pandolfi, R.J. Allan, D.B. Arenholz, E. Barroso-Luque, L. Campbell, S.I. Caswell, T.A. Blair, A. De Carlo, F. Fackler, S. Fournier, A.P. Freychet, G. Fukuto, M. G ü rsoy, D. Jiang, Z. Krishnan, H. Kumar, D. Kline, R.J. Li, R. Liman, C. Marchesini, S. Meh Tags: scattering tomography NEXAFS XAS spectroscopy SAXS GISAXS WAXS GIWAXS software computer programs Source Type: research
An all-diamond X-ray position and flux monitor using nitrogen-incorporated ultra-nanocrystalline diamond contacts
Diamond X-ray detectors with conducting nitrogen-incorporated ultra-nanocrystalline diamond (N-UNCD) films as electrodes were fabricated to measure X-ray beam flux and position. Structural characterization and functionality tests were performed for these devices. The N-UNCD films grown on unseeded diamond substrates were compared with N-UNCD films grown on a seeded silicon substrate. The feasibility of the N-UNCD films acting as electrodes for X-ray detectors was confirmed by the stable performance in a monochromatic X-ray beam. The fabrication process is able to change the surface status which may influence the signal uni...
Source: Journal of Synchrotron Radiation - May 31, 2018 Category: Physics Authors: Zou, M. Gaowei, M. Zhou, T. Sumant, A.V. Jaye, C. Fisher, D.A. Bohon, J. Smedley, J. Muller, E.M. Tags: X-ray detector beam position monitor diamond ultra-nanocrystalline flux monitor research papers Source Type: research
Performance of quartz- and sapphire-based double-crystal high-resolution ( ∼ 10 meV) RIXS monochromators under varying power loads
In the context of a novel, high-resolution resonant inelastic X-ray scattering spectrometer, a flat-crystal-based quartz analyzer system has recently been demonstrated to provide an unprecedented intrinsic-energy resolution of 3.9 meV at the Ir L3 absorption edge (11.215 keV) [Kim et al. (2018) Sci. Rep. 8, 1958]. However, the overall instrument resolution was limited to 9.7 meV because of an 8.9 meV incident band pass, generated by the available high-resolution four-bounce Si(844) monochromator. In order to better match the potent resolving power of the novel analyzer with the energy band pass of the incid...
Source: Journal of Synchrotron Radiation - May 31, 2018 Category: Physics Authors: Gog, T. Casa, D.M. Knopp, J. Kim, J. Upton, M.H. Krakora, R. Jaski, A. Said, A. Yava ş , H. Gretarsson, H. Huang, X.R. Tags: X-ray optics resonant inelastic X-ray scattering RIXS non-traditional crystal materials high-resolution monochromators research papers Source Type: research
In situ coherent X-ray diffraction imaging of radiation-induced mass loss in metal – polymer composite spheres
In this study, CXDI has been used to monitor radiation-induced structural changes in metal-coated poly(methyl methacrylate) microspheres. Using a coherent undulator X-ray beam with 8.10 keV photon energy, 14 tomograms at a resolution of ∼ 30 nm were measured consecutively, which resulted in an accumulated dose of 30 GGy. The three-dimensional images confirmed that the polymer core was strongly affected by the absorbed dose, giving pronounced mass loss. Specifically, as the metal – polymer composite was exposed to the X-ray beam, a bubble-like region of reduced density grew within the composite, almost...
Source: Journal of Synchrotron Radiation - May 31, 2018 Category: Physics Authors: Skj ø nsfjell, E.T.B. Chushkin, Y. Zontone, F. Breiby, D.W. Tags: coherent X-ray diffraction imaging radiation damage X-ray photon correlation spectroscopy research papers Source Type: research
Synchrotron inline phase contrast µ CT enables detailed virtual histology of embedded soft-tissue samples with and without staining
In this study, PBI yielded a strong increase in image quality even at lower radiation doses and consequently prevented any damage to the tissue samples or the embedding material. This work has demonstrated that the improvement in contrast-to-noise ratio by PBI enabled label-free virtual histology of soft-tissue specimens embedded in paraffin to a level of detail that exceeds that achieved with staining protocols. (Source: Journal of Synchrotron Radiation)
Source: Journal of Synchrotron Radiation - May 31, 2018 Category: Physics Authors: Saccomano, M. Albers, J. Tromba, G. Dobrivojevi ć Radmilovi ć , M. Gajovi ć , S. Alves, F. Dullin, C. Tags: virtual histology ex vivo staining SR µ CT synchrotron radiation research papers Source Type: research
3D reconstruction of magnetization from dichroic soft X-ray transmission tomography
The development of magnetic nanostructures for applications in spintronics requires methods capable of visualizing their magnetization. Soft X-ray magnetic imaging combined with circular magnetic dichroism allows nanostructures up to 100 – 300 nm in thickness to be probed with resolutions of 20 – 40 nm. Here a new iterative tomographic reconstruction method to extract the three-dimensional magnetization configuration from tomographic projections is presented. The vector field is reconstructed by using a modified algebraic reconstruction approach based on solving a set of linear equations in an iterative...
Source: Journal of Synchrotron Radiation - May 30, 2018 Category: Physics Authors: Hierro-Rodriguez, A. G ü rsoy, D. Phatak, C. Quir ó s, C. Sorrentino, A. Á lvarez-Prado, L.M. V é lez, M. Mart í n, J.I. Alameda, J.M. Pereiro, E. Ferrer, S. Tags: soft X-ray transmission microscopy X-ray transmission tomography vector field tomography magnetization configuration reconstruction research papers Source Type: research
Single-particle XFEL 3D reconstruction of ribosome-size particles based on Fourier slice matching: requirements to reach subnanometer resolution
In this study, as an example, the restoration of 3D structure of ribosome from two-dimensional diffraction patterns created by simulation is shown. Tests are performed using the diffraction patterns simulated for different beam intensities and using different numbers of these patterns. Guidelines for selecting parameters for slice-matching 3D reconstruction procedures are established. Also, the minimum requirements for XFEL experimental conditions to obtain diffraction patterns for reconstructing molecular structures to a high-resolution of a few nanometers are discussed. (Source: Journal of Synchrotron Radiation)
Source: Journal of Synchrotron Radiation - May 30, 2018 Category: Physics Authors: Nakano, M. Miyashita, O. Jonic, S. Tokuhisa, A. Tama, F. Tags: 3D reconstruction single-particle analysis X-ray free-electron laser coherent X-ray diffraction imaging research papers Source Type: research
The challenge of constructing an international XAFS database
The present state of XAFS databases, particularly in Japan, and proposals for future directions are presented. International collaboration is important for enlarging the database for further development of XAFS spectroscopy. (Source: Journal of Synchrotron Radiation)
Source: Journal of Synchrotron Radiation - May 30, 2018 Category: Physics Authors: Asakura, K. Abe, H. Kimura, M. Tags: XAFS database automatic data deposition data repository system research papers Source Type: research
Propagation of uncertainty in experiment: structures of Ni (II) coordination complexes
Accurate experimental XAFS (X-ray absorption fine-structure) data including uncertainties are required during analysis for valid comparison of results and conclusions of hypothesis testing on structural determinations. Here an approach is developed to investigate data without standard interpolation of experimental data and with minimal loss of information content in the raw data. Nickel coordination complexes bis(i-n-propylsalicylaldiminato)nickel(II) (i-pr) and bis(N-n-propylsalicylaldiminato)nickel(II) (n-pr) are investigated. The additional physical insight afforded by the correct propagation of experimental uncertainty...
Source: Journal of Synchrotron Radiation - May 30, 2018 Category: Physics Authors: Schalken, M.J. Chantler, C.T. Tags: XAFS information content uncertainty nickel coordination complexes research papers Source Type: research
Fluorescence-detected XAS with sub-second time resolution reveals new details about the redox activity of Pt/CeO2 catalyst
A setup for fluorescence-detected X-ray absorption spectroscopy (XAS) with sub-second time resolution has been developed. This technique allows chemical speciation of low-concentrated materials embedded in highly absorbing matrices, which cannot be studied using transmission XAS. Using this setup, the reactivity of 1.5 wt% Pt/CeO2 catalyst was studied with 100 ms resolution during periodic cycling in CO- and oxygen-containing atmospheres in a plug-flow reactor. Measurements were performed at the Pt L3- and Ce L3-edges. The reactivity of platinum and cerium demonstrated a strong correlation. The oxidation of the cat...
Source: Journal of Synchrotron Radiation - May 30, 2018 Category: Physics Authors: Guda, A.A. Bugaev, A.L. Kopelent, R. Braglia, L. Soldatov, A.V. Nachtegaal, M. Safonova, O.V. Smolentsev, G. Tags: time-resolved XAS fluorescence detection heterogeneous catalysis transient kinetics CO oxidation automotive catalysts ceria platinum. research papers Source Type: research
The simple physics of the bending magnet spectrum
A new elementary model of the bending magnet synchrotron radiation is presented, with minimal mathematical formalism. The model explains features not justified by other simplified approaches; in particular, it brings to light the key role of the directional Doppler effect. (Source: Journal of Synchrotron Radiation)
Source: Journal of Synchrotron Radiation - May 29, 2018 Category: Physics Authors: Margaritondo, G. Tags: synchrotron bending magnets Doppler relativity X-rays teaching and education Source Type: research
Enhanced insulating behavior in the Ir-vacant Sr2Ir1 – xO4 system dominated by the local structure distortion
Sr2IrO4, known as the Jeff = 1/2 Mott insulator, was predicted to be an unconventional superconductor upon doping since it highly resembles the high-temperature cuprates. However, recent work pointed out an enhanced insulating behavior in the Ir-vacant Sr2Ir1 – xO4 system. In this contribution, to investigate the microscopic mechanism of its enhanced insulating behavior, X-ray absorption spectroscopy was applied to study the electronic structure and local structure distortion of Sr2Ir1 – xO4. Due to the presence of Ir5+ ions, the preconceived holes are barely doped in the Ir-vacant system. Nevertheless, Ir vaca...
Source: Journal of Synchrotron Radiation - May 29, 2018 Category: Physics Authors: Cheng, J. Dong, P. Li, B. Liu, S. Wang, X. Wang, Y. Li, X. Tags: Sr2Ir1 – xO4 X-ray absorption spectroscopy local structure distortion research papers Source Type: research
Improving the quality of XAFS data
Following the Q2XAFS Workshop and Satellite to IUCr Congress 2017 on `Data Acquisition, Treatment, Storage – quality assurance in XAFS spectroscopy', a summary is given of the discussion on different aspects of a XAFS experiment that affect data quality. Some pertinent problems ranging from sources and minimization of noise to harmonic contamination and uncompensated monochromator glitches were addressed. Also, an overview is given of the major limitations and pitfalls of a selection of related methods, such as photon-out spectroscopies and energy-dispersive XAFS, and of increasingly common applications, namely studi...
Source: Journal of Synchrotron Radiation - May 29, 2018 Category: Physics Authors: Abe, H. Aquilanti, G. Boada, R. Bunker, B. Glatzel, P. Nachtegaal, M. Pascarelli, S. Tags: XAFS quality of XAFS data sources of noise in XAFS harmonic rejection in XAFS good practice in XAFS experiments research papers Source Type: research
Using EXAFS data to improve atomistic structural models of glasses
Quantitative characterization of the atomic structure of multi-component glasses is a long-standing scientific challenge. This is because in most cases no single experimental technique is capable of completely resolving all aspects of a disordered system's structure. In this situation, the most practical solution for the materials scientist is to apply multiple experimental probes offering differing degrees of insight into a material's properties. This powerful and widely adopted approach does, however, transfer the characterization challenge to the task of developing a coherent data analysis framework that can appropriate...
Source: Journal of Synchrotron Radiation - May 29, 2018 Category: Physics Authors: Bowron, D.T. Tags: X-ray diffraction EXAFS glass structure empirical potential structure refinement (EPSR) research papers Source Type: research
A call for a round robin study of XAFS stability and platform dependence at synchrotron beamlines on well defined samples
Round robin studies have been used across fields of science for quality control testing and to investigate laboratory dependencies and cross-platform inconsistencies as well as to drive forward the improvement of understanding of experimental systems, systematic effects and theoretical limitations. Here, following the Q2XAFS Workshop and Satellite to IUCr Congress 2017 on `Data Acquisition, Treatment, Storage – quality assurance in XAFS spectroscopy', a mechanism is suggested for a suitable study across XAFS (X-ray absorption fine-structure) beamlines and facilities, to enable each beamline to cross-calibrate, provid...
Source: Journal of Synchrotron Radiation - May 29, 2018 Category: Physics Authors: Chantler, C.T. Bunker, B.A. Abe, H. Kimura, M. Newville, M. Welter, E. Tags: X-ray absorption fine structure XAFS round robin benchmarking research papers Source Type: research
Quanty4RIXS: a program for crystal field multiplet calculations of RIXS and RIXS – MCD spectra using Quanty
Some initial instructions for the Quanty4RIXS program written in MATLAB ® are provided. The program assists in the calculation of 1s 2p RIXS and 1s 2p RIXS – MCD spectra using Quanty. Furthermore, 1s XAS and 2p 3d RIXS calculations in different symmetries can also be performed. It includes the Hartree – Fock values for the Slater integrals and spin – orbit interactions for several 3d transition metal ions that are required to create the .lua scripts containing all necessary parameters and quantum mechanical definitions for the calculations. The program can be used free of c...
Source: Journal of Synchrotron Radiation - April 28, 2018 Category: Physics Authors: Zimmermann, P. Green, R.J. Haverkort, M.W. de Groot, F.M.F. Tags: Quanty RIXS – MCD crystal field CFT computer programs Source Type: research
Integrated beamline control and data acquisition for small-angle X-ray scattering at the P12 BioSAXS beamline at PETRAIII storage ring DESY
The versatility of small-angle X-ray scattering (SAXS) as a structural biology method is apparent by its compatibility with many experimental set-ups. Most advanced SAXS studies are conducted at dedicated synchrotron beamlines yielding high beam brilliance, throughput and temporal resolution. However, utilizing the full potential of the method while preserving a high degree of automation provides a challenge to any SAXS beamline. This challenge is especially pertinent at the P12 BioSAXS beamline of the EMBL at the PETRAIII Synchrotron DESY (Hamburg, Germany), optimized and dedicated to scattering of macromolecular solution...
Source: Journal of Synchrotron Radiation - April 25, 2018 Category: Physics Authors: Hajizadeh, N.R. Franke, D. Svergun, D.I. Tags: SAXS beamline control system data collection BECQUEREL alignment computer programs Source Type: research
Fast XANES fluorescence imaging using a Maia detector
A new fast X-ray absorption spectroscopy scanning method was recently implemented at the Hard X-ray Microprobe endstation P06, PETRA III, DESY, utilizing a Maia detector. Spectromicroscopy maps were acquired with spectra for X-ray absorption near-edge structure (XANES) acquisition in the sub-second regime. The method combines XANES measurements with raster-scanning of the sample through the focused beam. The order of the scanning sequence of the axes, one beam energy axis and two (or more) spatial axes, is a variable experimental parameter and, depending on it, the dwell at each location can be either single and continuous...
Source: Journal of Synchrotron Radiation - April 25, 2018 Category: Physics Authors: Boesenberg, U. Ryan, C.G. Kirkham, R. Jahn, A. Madsen, A. Moorhead, G. Falkenberg, G. Garrevoet, J. Tags: QXANES Maia detector micro-XRF spectromicroscopy beamlines Source Type: research
Study of melanin localization in the mature male Calopteryx haemorrhoidalis damselfly wings
In this study, infrared (IR) microspectroscopy, coupled with the highly collimated synchrotron IR beam, was employed in order to identify the distribution of the pigments in the wings at a high spatial resolution. It was found that the melanin is localized in the procuticle of the C. haemorrhoidalis damselfly wings, distributed homogeneously within this layer, and not associated with the lipids of the epicuticle. (Source: Journal of Synchrotron Radiation)
Source: Journal of Synchrotron Radiation - April 25, 2018 Category: Physics Authors: Truong, V.K. Vongsvivut, J. Mahanamanam, N. Tobin, M.J. Luque, P. Baulin, V. Werner, M. Maclaughlin, S. Crawford, R.J. Ivanova, E.P. Tags: Calopteryx haemorrhoidalis synchrotron IR microspectroscopy melanin damselfly hierarchical cluster analysis synchrotron Fourier transform infrared microspectroscopy short communications Source Type: research
A sagittally confined high-resolution spectrometer in the `water window'
The authors report a novel scheme for a grazing-incidence spectrometer forming an excellent meridional flat field in its detector domain to deliver the desired spectral resolution throughout the full designated spectral range, while reducing the sagittal astigmatism substantially to enhance the spectral intensity. The optical properties of the system are thoroughly investigated and optimized, and the detector plane is fitted well to the meridional or sagittal focal curves. The authors demonstrated that a resolving power of 6000 – 18000 could be achieved within the `water window' (2 – 5 nm) for an effective ...
Source: Journal of Synchrotron Radiation - April 25, 2018 Category: Physics Authors: Li, Z. Li, B. Tags: X-ray spectrometers water window geometric optics ray tracing diffraction principle optical aberration analysis and optimization research papers Source Type: research
Synchrotron radiation external beam rotational radiotherapy of breast cancer: proof of principle
The principle of rotational summation of the absorbed dose for breast cancer treatment with orthovoltage X-ray beams was proposed by J. Boone in 2012. Here, use of X-ray synchrotron radiation for image guided external beam rotational radiotherapy treatment of breast cancer is proposed. Tumor irradiation occurs with the patient in the prone position hosted on a rotating bed, with her breast hanging from a hole in the bed, which rotates around a vertical axis passing through the tumor site. Horizontal collimation of the X-ray beam provides for whole breast or partial breast irradiation, while vertical translation of the bed ...
Source: Journal of Synchrotron Radiation - April 25, 2018 Category: Physics Authors: Di Lillo, F. Mettivier, G. Castriconi, R. Sarno, A. Stevenson, A.W. Hall, C.J. H ä usermann, D. Russo, P. Tags: breast cancer radiotherapy synchrotron radiation Monte Carlo simulation research papers Source Type: research
Radiation-driven rotational motion of nanoparticles
Focused synchrotron beams can influence a studied sample via heating, or radiation pressure effects due to intensity gradients. The high angular sensitivity of rotational X-ray tracking of crystalline particles via their Bragg reflections can detect extremely small forces such as those caused by field gradients. By tracking the rotational motion of single-crystal nanoparticles embedded in a viscous or viscoelastic medium, the effects of heating in a uniform gradient beam and radiation pressure in a Gaussian profile beam were observed. Changes in viscosity due to X-ray heating were measured for 42 µ m crystals in ...
Source: Journal of Synchrotron Radiation - April 25, 2018 Category: Physics Authors: Liang, M. Harder, R. Robinson, I. Tags: rotational X-ray tracking radiation pressure rotational dynamics research papers Source Type: research
Thickness-dependent structural characteristics for a sputtering-deposited chromium monolayer and Cr/C and Cr/Sc multilayers
The interior structure, morphology and ligand surrounding of a sputtering-deposited chromium monolayer and Cr/C and Cr/Sc multilayers are determined by various hard X-ray techniques in order to reveal the growth characteristics of Cr-based thin films. A Cr monolayer presents a three-stage growth mode with sudden changes occurring at a layer thickness of ∼ 2 nm and beyond 6 nm. Cr-based multilayers are proven to have denser structures due to interfacial diffusion and layer growth mode. Cr/C and Cr/Sc multilayers have different interfacial widths resulting from asymmetry, degree of crystallinity and thermal stabi...
Source: Journal of Synchrotron Radiation - April 25, 2018 Category: Physics Authors: Jiang, H. Wang, H. Zhu, J. Xue, C. Zhang, J. Tian, N. Li, A. Tags: X-ray multilayer chromium interface growth ligand research papers Source Type: research