Temperature-dependent thermal properties of Ru/C multilayers
Multilayers made of Ru/C are the most promising candidates when working in the energy region 8 – 20   keV. The stability of its thermal properties, including thermal expansion and thermal conduction, needs to be considered for monochromator or focusing components. Ru/C multilayers with periodic thicknesses of 3, 4 and 5   nm were investigated in   situ by grazing-incidence X-ray reflectometry and diffuse scattering in order to study their thermal expansion characteristics as a function of annealing temperature up to 400 ° C. The thermal conductivity of multilayers with the same structure was also measured b...
Source: Journal of Synchrotron Radiation - July 28, 2017 Category: Physics Authors: Yan S. Jiang, H. Wang, H. He, Y. Li, A. Zheng, Y. Dong, Z. Tian, N. Tags: multilayer X-ray interface thermal conductivity research papers Source Type: research

Phase-merging enhanced harmonic generation free-electron laser with a normal modulator
A phase-merging enhanced harmonic generation free-electron laser (FEL) was proposed to increase the harmonic conversion efficiency of seeded FELs and promote the radiation wavelength towards the X-ray spectral region. However, this requires a specially designed transverse gradient undulator (TGU) as the modulator to couple the transverse and longitudinal phase space of the electron beam. In this paper, the generation of the phase-merging effect is explored using the natural field gradient of a normal planar undulator. In this method, a vertical dispersion on the electron beam is introduced and then the dispersed beam trave...
Source: Journal of Synchrotron Radiation - July 28, 2017 Category: Physics Authors: Zhao, Z. Li, H. Jia, Q. Tags: free-electron laser phase-merging effect natural transverse gradient beam orbit offset research papers Source Type: research

Current events
(Source: Journal of Synchrotron Radiation)
Source: Journal of Synchrotron Radiation - June 29, 2017 Category: Physics Authors: , Tags: current events Source Type: research

The relativistic foundations of synchrotron radiation
Special relativity (SR) determines the properties of synchrotron radiation, but the corresponding mechanisms are frequently misunderstood. Time dilation is often invoked among the causes, whereas its role would violate the principles of SR. Here it is shown that the correct explanation of the synchrotron radiation properties is provided by a combination of the Doppler shift, not dependent on time dilation effects, contrary to a common belief, and of the Lorentz transformation into the particle reference frame of the electromagnetic field of the emission-inducing device, also with no contribution from time dilation. Conclud...
Source: Journal of Synchrotron Radiation - June 20, 2017 Category: Physics Authors: Margaritondo, G. Rafelski, J. Tags: special relativity Doppler time dilation Lorentz transformation teaching and education Source Type: research

Accuracy of stress measurement by Laue microdiffraction (Laue-DIC method): the influence of image noise, calibration errors and spot number
Laue microdiffraction, available at several synchrotron radiation facilities, is well suited for measuring the intragranular stress field in deformed materials thanks to the achievable submicrometer beam size. The traditional method for extracting elastic strain (and hence stress) and lattice orientation from a microdiffraction image relies on fitting each Laue spot with an analytical function to estimate the peak position on the detector screen. The method is thus limited to spots exhibiting ellipsoidal shapes, thereby impeding the study of specimens plastically deformed. To overcome this difficulty, the so-called Laue-DI...
Source: Journal of Synchrotron Radiation - June 20, 2017 Category: Physics Authors: Zhang, F.G. Bornert, M. Petit, J. Castelnau, O. Tags: Laue microdiffraction image noise digital image correlation stress analysis research papers Source Type: research

Rotatable high-resolution ARPES system for tunable linear-polarization geometry
A rotatable high-resolution angle-resolved photoemission spectroscopy (ARPES) system has been developed to utilize tunable linear-polarization geometries on the linear undulator beamline (BL-1) at Hiroshima Synchrotron Radiation Center. By rotating the whole ARPES measurement system, the photoelectron detection plane can be continuously changed from parallel to normal against the electric field vector of linearly polarized undulator radiation. This polarization tunability enables us to identify the symmetry of the initial electronic states with respect to the mirror planes, and to selectively observe the electronic states ...
Source: Journal of Synchrotron Radiation - June 19, 2017 Category: Physics Authors: Iwasawa, H. Shimada, K. Schwier, E.F. Zheng, M. Kojima, Y. Hayashi, H. Jiang, J. Higashiguchi, M. Aiura, Y. Namatame, H. Taniguchi, M. Tags: angle-resolved photoemission spectroscopy (ARPES) rotatable high-resolution ARPES system linear polarization condensed-matter physics research papers Source Type: research

Pump − probe experiments at the TEMPO beamline using the low- α operation mode of Synchrotron SOLEIL
The SOLEIL synchrotron radiation source is regularly operated in special filling modes dedicated to pump – probe experiments. Among others, the low- α mode operation is characterized by shorter pulse duration and represents the natural bridge between 50   ps synchrotron pulses and femtosecond experiments. Here, the capabilities in low- α mode of the experimental set-ups developed at the TEMPO beamline to perform pump – probe experiments with soft X-rays based on photoelectron or photon detection are presented. A 282   kHz repetition-rate femtosecond laser is synchronized with the synchrotron rad...
Source: Journal of Synchrotron Radiation - June 15, 2017 Category: Physics Authors: Silly, M.G. Fert é , T. Tordeux, M.A. Pierucci, D. Beaulieu, N. Chauvet, C. Pressacco, F. Sirotti, F. Popescu, H. Lopez-Flores, V. Tortarolo, M. Sacchi, M. Jaouen, N. Hollander, P. Ricaud, J.P. Bergeard, N. Boeglin, C. Tudu, B. Delaunay, R. Luning, J. Ma Tags: time-resolved spectroscopy pump – probe experiments beamlines Source Type: research

Numerical simulations of the hard X-ray pulse intensity distribution at the Linac Coherent Light Source
Numerical simulations of the current and future pulse intensity distributions at selected locations along the Far Experimental Hall, the hard X-ray section of the Linac Coherent Light Source (LCLS), are provided. Estimates are given for the pulse fluence, energy and size in and out of focus, taking into account effects due to the experimentally measured divergence of the X-ray beam, and measured figure errors of all X-ray optics in the beam path. Out-of-focus results are validated by comparison with experimental data. Previous work is expanded on, providing quantitatively correct predictions of the pulse intensity distribu...
Source: Journal of Synchrotron Radiation - June 15, 2017 Category: Physics Authors: Pardini, T. Aquila, A. Boutet, S. Cocco, D. Hau-Riege, S.P. Tags: XFEL LCLS wavefront propagation simulations X-ray optics research papers Source Type: research

Protective radiolucent aluminium oxide coatings for   beryllium X-ray optics
Beryllium, being one of the most transparent materials to X-ray radiation, has become the material of choice for X-ray optics instrumentation at synchrotron radiation sources and free-electron laser facilities. However, there are concerns due to its high toxicity and, consequently, there is a need for special safety regulations. The authors propose to apply protective coatings in order to seal off beryllium from the ambient atmosphere, thus preventing degradation processes providing additional protection for users and prolonging the service time of the optical elements. This paper presents durability test results for Be wi...
Source: Journal of Synchrotron Radiation - June 15, 2017 Category: Physics Authors: Yurkevich, O. Maksimova, K. Goikhman, A. Grunin, A. Prokopovich, P. Tyurin, A. Medvedskaya, P. Lyatun, I. Snigireva, I. Snigirev, A. Tags: beryllium optics protective coatings aluminium oxide research papers Source Type: research

X-ray reflectivity measurement of interdiffusion in   metallic multilayers during rapid heating
A technique for measuring interdiffusion in multilayer materials during rapid heating using X-ray reflectivity is described. In this technique the sample is bent to achieve a range of incident angles simultaneously, and the scattered intensity is recorded on a fast high-dynamic-range mixed-mode pixel array detector. Heating of the multilayer is achieved by electrical resistive heating of the silicon substrate, monitored by an infrared pyrometer. As an example, reflectivity data from Al/Ni heated at rates up to 200   K   s − 1 are presented. At short times the interdiffusion coefficient can be determined from the ...
Source: Journal of Synchrotron Radiation - June 15, 2017 Category: Physics Authors: Liu, J.P. Kirchhoff, J. Zhou, L. Zhao, M. Grapes, M.D. Dale, D.S. Tate, M.D. Philipp, H.T. Gruner, S.M. Weihs, T.P. Hufnagel, T.C. Tags: X-ray reflectivity multilayer interdiffusion research papers Source Type: research

Effects of temperature, mechanical motion and source positional jitter on the resolving power of beamline 02B at the SSRF
A detailed analysis of the effects of temperature excursions, instrumental mechanical motion and source position jitter on the energy-resolving power of beamline 02B at the Shanghai Synchrotron Radiation Facility (SSRF) is presented in this study. This beamline uses a bending-magnet-based source and includes a variable-line-spacing grating monochromator with additional optics. Expressions are derived for the monochromator output photon energy shifts for each of the performance challenges considered. The calculated results indicate that measured temperature excursions of ± 1   K produce an energy shift of less than...
Source: Journal of Synchrotron Radiation - June 14, 2017 Category: Physics Authors: Guo, Z. Meng, X. Wang, Y. Liu, H. Zhang, X. Li, Z. Xue, L. Tai, R. Tags: variable-line-spacing grating mechanical vibration source positional jitter energy-resolving power beamlines Source Type: research

Three-dimensional reconstruction for coherent diffraction patterns obtained by XFEL
The three-dimensional (3D) structural analysis of single particles using an X-ray free-electron laser (XFEL) is a new structural biology technique that enables observations of molecules that are difficult to crystallize, such as flexible biomolecular complexes and living tissue in the state close to physiological conditions. In order to restore the 3D structure from the diffraction patterns obtained by the XFEL, computational algorithms are necessary as the orientation of the incident beam with respect to the sample needs to be estimated. A program package for XFEL single-particle analysis based on the Xmipp software packa...
Source: Journal of Synchrotron Radiation - June 14, 2017 Category: Physics Authors: Nakano, M. Miyashita, O. Jonic, S. Song, C. Nam, D. Joti, Y. Tama, F. Tags: three-dimensional reconstruction single-particle analysis X-ray free-electron laser coherent X-ray diffraction imaging research papers Source Type: research

Normal tracing deflectometry using a secondary light source
Scanning deflectometric profilers based on an f – θ system are typical optical tools used to measure mirror profiles at many synchrotron facilities. Unlike these profilers, which are based on a pencil beam, here a secondary light source and a pinhole are used to construct a system that automatically selects a beam that will always pass through the pinhole and propagate along the normal direction of the measured area on the surface under test. By measuring the angle variation of the selected beam, slope variations of the surface under test can be measured. Systematic errors introduced by manufacturing defects or...
Source: Journal of Synchrotron Radiation - June 14, 2017 Category: Physics Authors: Peng, C.Q. He, Y.M. Wang, J. Tags: normal tracing method secondary light source deflectometric profiler beam lateral motion aberration inhomogeneity research papers Source Type: research

Structural variation in a synchrotron-induced contamination layer (a-C:H) deposited on a toroidal Au mirror surface
A carbon layer deposited on an optical component is the result of complex interactions between the optical surface, adsorbed hydrocarbons, photons and secondary electrons (photoelectrons generated on the surface of optical elements). In the present study a synchrotron-induced contamination layer on a 340   mm × 60   mm Au-coated toroidal mirror has been characterized. The contamination layer showed a strong variation in structural properties from the centre of the mirror to the edge region (along the long dimension of the mirror) due to the Gaussian distribution of the incident photon beam intensity/power on the ...
Source: Journal of Synchrotron Radiation - June 13, 2017 Category: Physics Authors: Yadav, P.K. Gupta, R.K. Swami, M.K. Modi, M.H. Tags: reflectivity Raman spectroscopy X-ray diffraction hydrogenerated carbon research papers Source Type: research

Very efficient spin polarization analysis (VESPA): new exchange scattering-based setup for spin-resolved ARPES at APE-NFFA beamline at Elettra
Complete photoemission experiments, enabling measurement of the full quantum set of the photoelectron final state, are in high demand for studying materials and nanostructures whose properties are determined by strong electron and spin correlations. Here the implementation of the new spin polarimeter VESPA (Very Efficient Spin Polarization Analysis) at the APE-NFFA beamline at Elettra is reported, which is based on the exchange coupling between the photoelectron spin and a ferromagnetic surface in a reflectometry setup. The system was designed to be integrated with a dedicated Scienta-Omicron DA30 electron energy analyzer ...
Source: Journal of Synchrotron Radiation - June 13, 2017 Category: Physics Authors: Bigi, C. Das, P.K. Benedetti, D. Salvador, F. Krizmancic, D. Sergo, R. Martin, A. Panaccione, G. Rossi, G. Fujii, J. Vobornik, I. Tags: spin-resolved ARPES VLEED polarimeter research papers Source Type: research

Using refractive optics to broaden the focus of an X-ray mirror
X-ray mirrors are widely used at synchrotron radiation sources for focusing X-rays into focal spots of size less than 1   µ m. The ability of the beamline optics to change the size of this spot over a range up to tens of micrometres can be an advantage for many experiments such as X-ray microprobe and X-ray diffraction from micrometre-scale crystals. It is a requirement that the beam size change should be reproducible and it is often essential that the change should be rapid, for example taking less than 1   s, in order to allow high data collection rates at modern X-ray sources. In order to provide a controlled ...
Source: Journal of Synchrotron Radiation - May 30, 2017 Category: Physics Authors: Laundy, D. Sawhney, K. Dhamgaye, V. Tags: X-ray focusing refractive optics research papers Source Type: research

In situ electrochemical high-energy X-ray diffraction using a capillary working electrode cell geometry
The ability to generate new electrochemically active materials for energy generation and storage with improved properties will likely be derived from an understanding of atomic-scale structure/function relationships during electrochemical events. Here, the design and implementation of a new capillary electrochemical cell designed specifically for in situ high-energy X-ray diffraction measurements is described. By increasing the amount of electrochemically active material in the X-ray path while implementing low-Z cell materials with anisotropic scattering profiles, an order of magnitude enhancement in diffracted X-ray sign...
Source: Journal of Synchrotron Radiation - May 26, 2017 Category: Physics Authors: Young, M.J. Bedford, N.M. Jiang, N. Lin, D. Dai, L. Tags: electrochemistry atomic structure flow cell nanoparticles pair distribution function research papers Source Type: research

A method to stabilize the incident X-ray energy for anomalous diffraction measurements
A method to calibrate and stabilize the incident X-ray energy for anomalous diffraction data collection is provided and has been successfully used at the single-crystal diffraction beamline 1W2B at the Beijing Synchrotron Radiation Facilities. Employing a feedback loop to control the movement of the double-crystal monochromator, this new method enables the incident X-ray energy to be kept within a 0.2   eV range at the inflection point of the absorption edge. (Source: Journal of Synchrotron Radiation)
Source: Journal of Synchrotron Radiation - May 19, 2017 Category: Physics Authors: Wang, W. Yang, X. Chang, G. An, P. Cha, K. Dong, Y. Liu, P. Tags: energy stability monochromator anomalous diffraction feedback absorption edge. research papers Source Type: research

Insight into growth of Au – Pt bimetallic nanoparticles: an in   situ XAS study
Au – Pt bimetallic nanoparticles have been synthesized through a one-pot synthesis route from their respective chloride precursors using block copolymer as a stabilizer. Growth of the nanoparticles has been studied by simultaneous in   situ measurement of X-ray absorption spectroscopy (XAS) and UV – Vis spectroscopy at the energy-dispersive EXAFS beamline (BL-08) at Indus-2 SRS at RRCAT, Indore, India. In   situ XAS spectra, comprising both X-ray near-edge structure (XANES) and extended X-ray absorption fine-structure (EXAFS) parts, have been measured simultaneously at the Au and Pt L3-edges. While th...
Source: Journal of Synchrotron Radiation - May 18, 2017 Category: Physics Authors: Nayak, C. Bhattacharyya, D. Bhattacharyya, K. Tripathi, A.K. Bapat, R.D. Jha, S.N. Sahoo, N.K. Tags: XAS in   situ EXAFS XANES core – shell research papers Source Type: research

Comparison of phantom materials for use in quality assurance of microbeam radiation therapy
Microbeam radiation therapy (MRT) is a promising radiotherapy modality that uses arrays of spatially fractionated micrometre-sized beams of synchrotron radiation to irradiate tumours. Routine dosimetry quality assurance (QA) prior to treatment is necessary to identify any changes in beam condition from the treatment plan, and is undertaken using solid homogeneous phantoms. Solid phantoms are designed for, and routinely used in, megavoltage X-ray beam radiation therapy. These solid phantoms are not necessarily designed to be water-equivalent at low X-ray energies, and therefore may not be suitable for MRT QA. This work quan...
Source: Journal of Synchrotron Radiation - May 18, 2017 Category: Physics Authors: Cameron, M. Cornelius, I. Cutajar, D. Davis, J. Rosenfeld, A. Lerch, M. Guatelli, S. Tags: microbeam radiation therapy polymer phantoms dosimetry Monte Carlo Geant4 research papers Source Type: research

Preclinical radiotherapy at the Australian Synchrotron's Imaging and Medical Beamline: instrumentation, dosimetry and a small-animal feasibility study
Therapeutic applications of synchrotron X-rays such as microbeam (MRT) and minibeam (MBRT) radiation therapy promise significant advantages over conventional clinical techniques for some diseases if successfully transferred to clinical practice. Preclinical studies show clear evidence that a number of normal tissues in animal models display a tolerance to much higher doses from MRT compared with conventional radiotherapy. However, a wide spread in the parameters studied makes it difficult to make any conclusions about the associated tumour control or normal tissue complication probabilities. To facilitate more systematic a...
Source: Journal of Synchrotron Radiation - May 18, 2017 Category: Physics Authors: Livingstone, J. Adam, J.F. Crosbie, J.C. Hall, C.J. Lye, J.E. McKinlay, J. Pelliccia, D. Pouzoulet, F. Prezado, Y. Stevenson, A.W. H ä usermann, D. Tags: radiotherapy preclinical dosimetry imaging research papers Source Type: research

Alternative difference analysis scheme combining R-space EXAFS fit with global optimization XANES fit for X-ray transient absorption spectroscopy
Time-resolved X-ray absorption spectroscopy (TR-XAS), based on the laser-pump/X-ray-probe method, is powerful in capturing the change of the geometrical and electronic structure of the absorbing atom upon excitation. TR-XAS data analysis is generally performed on the laser-on minus laser-off difference spectrum. Here, a new analysis scheme is presented for the TR-XAS difference fitting in both the extended X-ray absorption fine-structure (EXAFS) and the X-ray absorption near-edge structure (XANES) regions. R-space EXAFS difference fitting could quickly provide the main quantitative structure change of the first shell. The ...
Source: Journal of Synchrotron Radiation - May 17, 2017 Category: Physics Authors: Zhan, F. Tao, Y. Zhao, H. Tags: difference XAFS fit global optimization R-space core/shell substitution TR-XAS research papers Source Type: research

Potential of propagation-based synchrotron X-ray phase-contrast computed tomography for cardiac tissue engineering
Hydrogel-based cardiac tissue engineering offers great promise for myocardial infarction repair. The ability to visualize engineered systems in vivo in animal models is desired to monitor the performance of cardiac constructs. However, due to the low density and weak X-ray attenuation of hydrogels, conventional radiography and micro-computed tomography are unable to visualize the hydrogel cardiac constructs upon their implantation, thus limiting their use in animal systems. This paper presents a study on the optimization of synchrotron X-ray propagation-based phase-contrast imaging computed tomography (PCI-CT) for three-di...
Source: Journal of Synchrotron Radiation - May 17, 2017 Category: Physics Authors: Izadifar, M. Babyn, P. Chapman, D. Kelly, M.E. Chen, X. Tags: cardiac patch computed tomography hydrogel phase-contrast imaging tissue engineering research papers Source Type: research

Current events
(Source: Journal of Synchrotron Radiation)
Source: Journal of Synchrotron Radiation - April 28, 2017 Category: Physics Authors: , Tags: current events Source Type: research

Understanding the instrumental profile of synchrotron radiation X-ray powder diffraction beamlines
A Monte Carlo algorithm has been developed to calculate the instrumental profile function of a powder diffraction synchrotron beamline. Realistic models of all optical elements are implemented in a ray-tracing software. The proposed approach and the emerging paradigm have been investigated and verified for several existing X-ray powder diffraction beamlines. The results, which can be extended to further facilities, show a new and general way of assessing the contribution of instrumental broadening to synchrotron radiation data, based on ab   initio simulations. (Source: Journal of Synchrotron Radiation)
Source: Journal of Synchrotron Radiation - April 20, 2017 Category: Physics Authors: Rebuffi, L. S á nchez del R í o, M. Busetto, E. Scardi, P. Tags: ray-tracing powder diffraction instrumental profile function simulation research papers Source Type: research

Long, elliptically bent, active X-ray mirrors with slope errors < 200   nrad
Actively bent X-ray mirrors are important components of many synchrotron and X-ray free-electron laser beamlines. A high-quality optical surface and good bending performance are essential to ensure that the X-ray beam is accurately focused. Two elliptically bent X-ray mirror systems from FMB Oxford were characterized in the optical metrology laboratory at Diamond Light Source. A comparison of Diamond-NOM slope profilometry and finite-element analysis is presented to investigate how the 900   mm-long mirrors sag under gravity, and how this deformation can be adequately compensated using a single, spring-loaded compensator...
Source: Journal of Synchrotron Radiation - April 19, 2017 Category: Physics Authors: Nistea, I.T. Alcock, S.G. Kristiansen, P. Young, A. Tags: X-ray active optics mechanically bent mirrors optical metrology Diamond-NOM research papers Source Type: research

Fluid dynamics analysis of a gas attenuator for X-ray FELs under high-repetition-rate operation
Newtonian fluid dynamics simulations were performed using the Navier – Stokes – Fourier formulations to elucidate the short time-scale ( µ s and longer) evolution of the density and temperature distributions in an argon-gas-filled attenuator for an X-ray free-electron laser under high-repetition-rate operation. Both hydrodynamic motions of the gas molecules and thermal conductions were included in a finite-volume calculation. It was found that the hydrodynamic wave motions play the primary role in creating a density depression (also known as a filament) by advectively transporting gas particles away from ...
Source: Journal of Synchrotron Radiation - April 18, 2017 Category: Physics Authors: Yang, B. Wu, J. Raubenheimer, T.O. Feng, Y. Tags: filamentation X-ray FEL attenuation gas fluid dynamics thermal conduction research papers Source Type: research

Time-resolved XAFS measurement using quick-scanning techniques at BSRF
A new quick-scanning X-ray absorption fine-structure (QXAFS) system has been established on beamline 1W1B at the Beijing Synchrotron Radiation Facility. As an independent device, the QXAFS system can be employed by other beamlines equipped with a double-crystal monochromator to carry out quick energy scans and data acquisition. Both continuous-scan and trapezoidal-scan modes are available in this system to satisfy the time scale from subsecond (in the X-ray absorption near-edge structure region) to 1   min. Here, the trapezoidal-scan method is presented as being complementary to the continuous-scan method, in order to ma...
Source: Journal of Synchrotron Radiation - April 12, 2017 Category: Physics Authors: Chu, S. Zheng, L. An, P. Gong, H. Hu, T. Xie, Y. Zhang, J. Tags: time-resolved XAFS QXAFS 1W1B BSRF research papers Source Type: research

Effective aperture of X-ray compound refractive lenses
A new definition of the effective aperture of the X-ray compound refractive lens (CRL) is proposed. Both linear (one-dimensional) and circular (two-dimensional) CRLs are considered. It is shown that for a strongly absorbing CRL the real aperture does not influence the focusing properties and the effective aperture is determined by absorption. However, there are three ways to determine the effective aperture in terms of transparent CRLs. In the papers by Kohn [(2002). JETP Lett. 76, 600 – 603; (2003). J. Exp. Theor. Phys. 97, 204 – 215; (2009). J. Surface Investig. 3, 358 – 364; (2012). J. Synchrotron Rad....
Source: Journal of Synchrotron Radiation - April 12, 2017 Category: Physics Authors: Kohn, V.G. Tags: X-ray focusing theory compound refractive lens effective aperture X-ray absorption computer simulations research papers Source Type: research

Finite-element modelling of multilayer X-ray optics
Multilayer optical elements for hard X-rays are an attractive alternative to crystals whenever high photon flux and moderate energy resolution are required. Prediction of the temperature, strain and stress distribution in the multilayer optics is essential in designing the cooling scheme and optimizing geometrical parameters for multilayer optics. The finite-element analysis (FEA) model of the multilayer optics is a well established tool for doing so. Multilayers used in X-ray optics typically consist of hundreds of periods of two types of materials. The thickness of one period is a few nanometers. Most multilayers are coa...
Source: Journal of Synchrotron Radiation - April 11, 2017 Category: Physics Authors: Cheng, X. Zhang, L. Tags: finite-element analysis multilayer X-ray optics high heat load thermal stress computer programs Source Type: research

Radiography registration for mosaic tomography
A hybrid method of stitching X-ray computed tomography (CT) datasets is proposed and the feasibility to apply the scheme in a synchrotron tomography beamline with micrometre resolution is shown. The proposed method enables the field of view of the system to be extended while spatial resolution and experimental setup remain unchanged. The approach relies on taking full tomographic datasets at different positions in a mosaic array and registering the frames using Fourier phase correlation and a residue-based correlation. To ensure correlation correctness, the limits for the shifts are determined from the experimental motor p...
Source: Journal of Synchrotron Radiation - April 7, 2017 Category: Physics Authors: Vescovi, R.F.C. Cardoso, M.B. Miqueles, E.X. Tags: computed tomography mosaic tomography microtomography non-limited field of view research papers Source Type: research

Transverse gradient in Apple-type undulators
Apple-type undulators are globally recognized as the most flexible devices for the production of variable polarized light in the soft X-ray regime, both at synchrotron and free-electron laser facilities. Recently, the implementation of transverse gradient undulators has been proposed to enhance the performance of new generation light sources. In this paper it is demonstrated that Apple undulators do not only generate linear and elliptical polarized light but also variable transverse gradient under certain conditions. A general theoretical framework is introduced to evaluate the K-value and its transverse gradient for an Ap...
Source: Journal of Synchrotron Radiation - April 7, 2017 Category: Physics Authors: Calvi, M. Camenzuli, C. Prat, E. Schmidt, T. Tags: soft X-ray line Apple-type undulator transverse gradient undulator research papers Source Type: research

SUT-NANOTEC-SLRI beamline for X-ray absorption spectroscopy
The SUT-NANOTEC-SLRI beamline was constructed in 2012 as the flagship of the SUT-NANOTEC-SLRI Joint Research Facility for Synchrotron Utilization, co-established by Suranaree University of Technology (SUT), National Nanotechnology Center (NANOTEC) and Synchrotron Light Research Institute (SLRI). It is an intermediate-energy X-ray absorption spectroscopy (XAS) beamline at SLRI. The beamline delivers an unfocused monochromatic X-ray beam of tunable photon energy (1.25 – 10   keV). The maximum normal incident beam size is 13   mm (width) × 1   mm (height) with a photon flux of 3 × 108 to 2 × 1010...
Source: Journal of Synchrotron Radiation - April 4, 2017 Category: Physics Authors: Klysubun, W. Kidkhunthod, P. Tarawarakarn, P. Sombunchoo, P. Kongmark, C. Limpijumnong, S. Rujirawat, S. Yimnirun, R. Tumcharern, G. Faungnawakij, K. Tags: XAS beamline X-ray absorption spectroscopy Mg K-edge XANES Al K-edge XANES S K-edge XANES Cu K-edge XANES intermediate-energy X-ray beamline beamlines Source Type: research

Nanofabrication and characterization of a grating-based condenser for uniform illumination with hard X-rays
In the development of full-field transmission X-ray microscopy for basic study in science and technology, a condenser capable of providing intense illumination with high uniformity and stability on tested specimens in order to achieve high-quality images is essential. The latest design of a square-shaped condenser based on diffractive gratings has demonstrated promising uniformity in illumination. This paper describes in more detail the development of such a beam shaper for hard X-rays at 10   keV with regard to its design, manufacture and optical characterization. The effect of the grating profile on the diffracted inte...
Source: Journal of Synchrotron Radiation - April 4, 2017 Category: Physics Authors: Liu, J. Li, X. Chen, S. Zhang, S. Xie, S. Xu, C. Chen, Y. Deng, B. Mao, C. Tags: condenser uniform illumination gratings nanofabrication hard X-ray optics research papers Source Type: research

Non-contact luminescence lifetime cryothermometry for macromolecular crystallography
Temperature is a very important parameter when aiming to minimize radiation damage to biological samples during experiments that utilize intense ionizing radiation. A novel technique for remote, non-contact, in situ monitoring of the protein crystal temperature has been developed for the new I23 beamline at the Diamond Light Source, a facility dedicated to macromolecular crystallography (MX) with long-wavelength X-rays. The temperature is derived from the temperature-dependent decay time constant of luminescence from a minuscule scintillation sensor ( (Source: Journal of Synchrotron Radiation)
Source: Journal of Synchrotron Radiation - April 4, 2017 Category: Physics Authors: Mykhaylyk, V.B. Wagner, A. Kraus, H. Tags: cryogenic thermometry luminescence lifetime protein crystalography bismuth germanate (BGO) research papers Source Type: research

A high-pressure single-crystal-diffraction experimental system at 4W2 beamline of BSRF
Information on the structural evolution of materials under high pressure is of great importance for understanding the properties of materials exhibited under high pressure. High-pressure powder diffraction is widely used to investigate the structure evolution of materials at such pressure. Unfortunately, powder diffraction data are usually insufficient for retrieving the atomic structures, with high-pressure single-crystal diffraction being more desirable for such a purpose. Here, a high-pressure single-crystal diffraction experimental system developed recently at beamline 4W2 of Beijing Synchrotron Radiation Facility (BSR...
Source: Journal of Synchrotron Radiation - April 3, 2017 Category: Physics Authors: Li, X. Li, H. Li, P. Li, R. Liu, J. Li, Y. Cui, W. Tags: high pressure single crystal XRD beamlines Source Type: research

Fresnel zone plate with apodized aperture for hard X-ray Gaussian beam optics
Fresnel zone plates with apodized apertures [apodization FZPs (A-FZPs)] have been developed to realise Gaussian beam optics in the hard X-ray region. The designed zone depth of A-FZPs gradually decreases from the center to peripheral regions. Such a zone structure forms a Gaussian-like smooth-shouldered aperture function which optically behaves as an apodization filter and produces a Gaussian-like focusing spot profile. Optical properties of two types of A-FZP, i.e. a circular type and a one-dimensional type, have been evaluated by using a microbeam knife-edge scan test, and have been carefully compared with those of norma...
Source: Journal of Synchrotron Radiation - April 3, 2017 Category: Physics Authors: Takeuchi, A. Uesugi, K. Suzuki, Y. Itabashi, S. Oda, M. Tags: Fresnel zone plate X-ray microscopy apodization Gaussian beam optics research papers Source Type: research

SOLEIL shining on the solution-state structure of biomacromolecules by synchrotron X-ray footprinting at the Metrology beamline
Synchrotron X-ray footprinting complements the techniques commonly used to define the structure of molecules such as crystallography, small-angle X-ray scattering and nuclear magnetic resonance. It is remarkably useful in probing the structure and interactions of proteins with lipids, nucleic acids or with other proteins in solution, often better reflecting the in vivo state dynamics. To date, most X-ray footprinting studies have been carried out at the National Synchrotron Light Source, USA, and at the European Synchrotron Radiation Facility in Grenoble, France. This work presents X-ray footprinting of biomolecules perfor...
Source: Journal of Synchrotron Radiation - March 24, 2017 Category: Physics Authors: Baud, A. Aym é , L. Gonnet, F. Salard, I. Gohon, Y. Jolivet, P. Brodolin, K. Da Silva, P. Giuliani, A. Sclavi, B. Chardot, T. Merc è re, P. Roblin, P. Daniel, R. Tags: structural proteomics X-ray footprinting mass spectrometry C3b factor H S3 oleosin research papers Source Type: research

The coherent radiation fraction of low-emittance synchrotrons
In this work the coherence properties of the synchrotron radiation beam from an X-ray undulator in a fourth-generation storage ring are analyzed. A slightly focused X-ray beam is simulated using a wavefront propagation through a non-redundant array of slits and the mutual coherence function is directly obtained and compared with the Gaussian – Schell approximation. The numerical wave propagation and the approximate analytical approaches are shown to agree qualitatively, and it is also shown that, when the coherent fraction is selected by a finite aperture before the focusing element, even achromatic focusing systems ...
Source: Journal of Synchrotron Radiation - March 24, 2017 Category: Physics Authors: Westfahl H. Jr Lordano Luiz, S.A. Meyer, B.C. Meneau, F. Tags: coherence Gaussian – Schell diffraction-limit storage ring research papers Source Type: research

Complex solutions under shear and pressure: a rheometer setup for X-ray scattering experiments
A newly developed high-pressure rheometer for in situ X-ray scattering experiments is described. A commercial rheometer was modified in such a way that X-ray scattering experiments can be performed under different pressures and shear. First experiments were carried out on hyaluronan, a ubiquitous biopolymer that is important for different functions in the body such as articular joint lubrication. The data hint at a decreased electrostatic interaction at higher pressure, presumably due to the increase of the dielectric constant of water by 3% and the decrease of the free volume at 300   bar. (Source: Journal of Synchrotron Radiation)
Source: Journal of Synchrotron Radiation - March 22, 2017 Category: Physics Authors: Wieland, D.C.F. Zander, T. Garamus, V.M. Krywka, C. Dedinaite, A. Claesson, P. Willumeit-R ö mer, R. Tags: rheology pressure small-angle X-ray scattering complex solutions hyaluronan research papers Source Type: research

Hard X-ray-induced damage on carbon – binder matrix for in situ synchrotron transmission X-ray microscopy tomography of Li-ion batteries
The electrode of Li-ion batteries is required to be chemically and mechanically stable in the electrolyte environment for in situ monitoring by transmission X-ray microscopy (TXM). Evidence has shown that continuous irradiation has an impact on the microstructure and the electrochemical performance of the electrode. To identify the root cause of the radiation damage, a wire-shaped electrode is soaked in an electrolyte in a quartz capillary and monitored using TXM under hard X-ray illumination. The results show that expansion of the carbon – binder matrix by the accumulated X-ray dose is the key factor of radiation da...
Source: Journal of Synchrotron Radiation - March 21, 2017 Category: Physics Authors: Lim, C. Kang, H. De Andrade, V. De Carlo, F. Zhu, L. Tags: radiation damage Li ion battery in   situ carbon – binder matrix intermittent dose short communications Source Type: research

Development of picosecond time-resolved X-ray absorption spectroscopy by high-repetition-rate laser pump/X-ray probe at Beijing Synchrotron Radiation Facility
A new setup and commissioning of transient X-ray absorption spectroscopy are described, based on the high-repetition-rate laser pump/X-ray probe method, at the 1W2B wiggler beamline at the Beijing Synchrotron Radiation Facility. A high-repetition-rate and high-power laser is incorporated into the setup with in-house-built avalanche photodiodes as detectors. A simple acquisition scheme was applied to obtain laser-on and laser-off signals simultaneously. The capability of picosecond transient X-ray absorption spectroscopy measurement was demonstrated for a photo-induced spin-crossover iron complex in 6   mM solution with 1...
Source: Journal of Synchrotron Radiation - March 21, 2017 Category: Physics Authors: Wang, H. Yu, C. Wei, X. Gao, Z. Xu, G.-L. Sun, D.-R. Li, Z. Zhou, Y. Li, Q.-J. Zhang, B.-B. Xu, J.-Q. Wang, L. Zhang, Y. Tan, Y.-L. Tao, Y. Tags: laser pump/X-ray probe X-ray absorption spectroscopy high repetition rate research papers Source Type: research

Respiratory-gated KES imaging of a rat model of acute lung injury at the Canadian Light Source
In this study, contrast-enhanced X-ray tomographic imaging for monitoring and quantifying respiratory disease in preclinical rodent models is proposed. A K-edge imaging method has been developed at the Canadian Light Source to very accurately obtain measurements of the concentration of iodinated contrast agent in the pulmonary vasculature and inhaled xenon in the airspaces of rats. To compare the iodine and xenon concentration maps, a scout projection image was acquired to define the region of interest within the thorax for imaging and to ensure the same locations were imaged in each K-edge subtraction (KES) acquisition. A...
Source: Journal of Synchrotron Radiation - March 21, 2017 Category: Physics Authors: Deman, P. Tan, S. Belev, G. Samadi, N. Martinson, M. Chapman, D. Ford, N.L. Tags: K-edge subtraction respiratory gated in vivo imaging contrast enhanced lung injury research papers Source Type: research

Advances in testing the effect of acceleration on time dilation using a synchrotron M ö ssbauer source
New results, additional techniques and know-how acquired, developed and employed in a recent HC-1898 experiment at the Nuclear Resonance Beamline ID18 of ESRF are presented, in the quest to explore the acceleration effect on time dilation. Using the specially modified Synchrotron M ö ssbauer Source and KB-optics together with a rotating single-line semicircular M ö ssbauer absorber on the rim of a specially designed rotating disk, the aim was to measure the relative spectral shift between the spectra of two states when the acceleration of the absorber is anti-parallel and parallel to the source. A control system ...
Source: Journal of Synchrotron Radiation - March 20, 2017 Category: Physics Authors: Friedman, Y. Nowik, I. Felner, I. Steiner, J.M. Yudkin, E. Livshitz, S. Wille, H.-C. Wortmann, G. Chumakov, A.I. Tags: acceleration time dilation ö ssbauer spectrum research papers Source Type: research

Development of optical choppers for time-resolved measurements at soft X-ray synchrotron radiation beamlines
Two types of optical choppers for time-resolved measurements at synchrotron radiation soft X-ray beamlines have been developed. One type uses an air-spindle-type rotation mechanism with a two-stage differential pumping system to maintain the ultra-high vacuum of the X-ray beamline, and the other uses a magnetic bearing. Both can be installed at the soft X-ray beamlines at SPring-8, greatly improving the accessibility of pump-and-probe spectroscopy. The combination of X-ray chopper and pump-and-probe photoemission electron microscope at SPring-8 provides drastic improvements in signal-to-noise ratio and resolution compared ...
Source: Journal of Synchrotron Radiation - March 20, 2017 Category: Physics Authors: Osawa, H. Ohkochi, T. Fujisawa, M. Kimura, S. Kinoshita, T. Tags: X-ray chopper soft X-ray time-resolved measurements ultra-high vacuum research papers Source Type: research

Caltrop particles synthesized by photochemical reaction induced by X-ray radiolysis
X-ray radiolysis of a Cu(CH3COO)2 solution was observed to produce caltrop-shaped particles of cupric oxide (CuO, Cu2O), which were characterized using high-resolution scanning electron microscopy and micro-Raman spectrometry. X-ray irradiation from a synchrotron source drove the room-temperature synthesis of submicrometer- and micrometer-scale cupric oxide caltrop particles from an aqueous Cu(CH3COO)2 solution spiked with ethanol. The size of the caltrop particles depended on the ratio of ethanol in the stock solution and the surface of the substrate. The results indicated that there were several synthetic routes to obtai...
Source: Journal of Synchrotron Radiation - March 20, 2017 Category: Physics Authors: Yamaguchi, A. Fukuoka, T. Okada, I. Ishihara, M. Sakurai, I. Utsumi, Y. Tags: radiolysis X-ray synthesis cupric oxide research papers Source Type: research

Study on the reflectivity properties of spherically bent analyser crystals. Corrigendum
Corrections to the paper by Honkanen et al. (2014). [J. Synchrotron Rad. 21, 104 – 110] are made. (Source: Journal of Synchrotron Radiation)
Source: Journal of Synchrotron Radiation - February 24, 2017 Category: Physics Authors: Honkanen, A.-P. Verbeni, R. Simonelli, L. Moretti Sala, M. Monaco, G. Huotari, S. Tags: high-energy-resolution analysers inelastic X-ray scattering bent crystals addenda and errata Source Type: research

Point focusing with flat and wedged crossed multilayer Laue lenses
Point focusing measurements using pairs of directly bonded crossed multilayer Laue lenses (MLLs) are reported. Several flat and wedged MLLs have been fabricated out of a single deposition and assembled to realise point focusing devices. The wedged lenses have been manufactured by adding a stress layer onto flat lenses. Subsequent bending of the structure changes the relative orientation of the layer interfaces towards the stress-wedged geometry. The characterization at ESRF beamline ID13 at a photon energy of 10.5   keV demonstrated a nearly diffraction-limited focusing to a clean spot of 43   nm × 44   nm with...
Source: Journal of Synchrotron Radiation - February 21, 2017 Category: Physics Authors: Kubec, A. Melzer, K. Gluch, J. Niese, S. Braun, S. Patommel, J. Burghammer, M. Leson, A. Tags: multilayer Laue lens X-ray nanofocusing ptychography scanning X-ray microscopy research papers Source Type: research

XDesign: an open-source software package for designing X-ray imaging phantoms and experiments
The development of new methods or utilization of current X-ray computed tomography methods is impeded by the substantial amount of expertise required to design an X-ray computed tomography experiment from beginning to end. In an attempt to make material models, data acquisition schemes and reconstruction algorithms more accessible to researchers lacking expertise in some of these areas, a software package is described here which can generate complex simulated phantoms and quantitatively evaluate new or existing data acquisition schemes and image reconstruction algorithms for targeted applications. (Source: Journal of Synchrotron Radiation)
Source: Journal of Synchrotron Radiation - February 21, 2017 Category: Physics Authors: Ching, D.J. G ü rsoy, D. Tags: tomography data acquisition simulation phantom scanning X-ray probe reconstruction quality open-source Python experiment design computer programs Source Type: research

Effects of organic ligands on Pb absorption and speciation changes in Arabidopsis as determined by   micro X-ray fluorescence and X-ray absorption near-edge structure analysis
Pb can pass through the food chain via plants and threaten human health, which has attracted widespread attention. Changes in Pb speciation affect its bioavailability in soils and water. However, whether organic ligands can change the uptake and mobility of Pb in plants and increase or decrease Pb bioavailability remains uncertain. To reveal the roles of organic and inorganic Pb in Pb metabolism in plants, the localization and speciation changes of Pb in Arabidopsis thaliana plants grown in organic and inorganic Pb were characterized by synchrotron radiation micro X-ray fluorescence and X-ray absorption near-edge structure...
Source: Journal of Synchrotron Radiation - February 21, 2017 Category: Physics Authors: Shen, Y.T. Song, Y.F. Tags: XANES µ -XRF lead plant speciation bioavailability iron plaque lead acetate research papers Source Type: research