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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Nanoscale mapping of carrier collection in single nanowire solar cells using X-ray beam induced current
Here it is demonstrated how nanofocused X-ray beam induced current (XBIC) can be used to quantitatively map the spatially dependent carrier collection probability within nanostructured solar cells. The photocurrent generated by a 50   nm-diameter X-ray beam was measured as a function of position, bias and flux in single p – i – n doped solar-cell nanowires. The signal gathered mostly from the middle segment decays exponentially toward the p- and n-segments, with a characteristic decay length that varies between 50   nm and 750   nm depending on the flux and the applied bias. The amplitude of the XBIC show...
Source: Journal of Synchrotron Radiation - November 1, 2018 Category: Physics Authors: Chayanun, L. Otnes, G. Troian, A. Hammarberg, S. Salomon, D. Borgstr ö m, M.T. Wallentin, J. Tags: X-ray beam induced current XBIC nanowires solar cells internal quantum efficiency IQE research papers Source Type: research

The Adaptive Gain Integrating Pixel Detector at the   European XFEL
The Adaptive Gain Integrating Pixel Detector (AGIPD) is an X-ray imager, custom designed for the European X-ray Free-Electron Laser (XFEL). It is a fast, low-noise integrating detector, with an adaptive gain amplifier per pixel. This has an equivalent noise of less than 1   keV when detecting single photons and, when switched into another gain state, a dynamic range of more than 104   photons of 12   keV. In burst mode the system is able to store 352 images while running at up to 6.5   MHz, which is compatible with the 4.5   MHz frame rate at the European XFEL. The AGIPD system was installed and commissioned in A...
Source: Journal of Synchrotron Radiation - November 1, 2018 Category: Physics Authors: Allahgholi, A. Becker, J. Delfs, A. Dinapoli, R. Goettlicher, P. Greiffenberg, D. Henrich, B. Hirsemann, H. Kuhn, M. Klanner, R. Klyuev, A. Krueger, H. Lange, S. Laurus, T. Marras, A. Mezza, D. Mozzanica, A. Niemann, M. Poehlsen, J. Schwandt, J. Sheviakov Tags: AGIPD X-ray detector European XFEL research papers Source Type: research

Nanoporous gold: a hierarchical and multiscale 3D test pattern for characterizing X-ray nano-tomography systems
Full-field transmission X-ray microscopy (TXM) is a well established technique, available at various synchrotron beamlines around the world as well as by laboratory benchtop devices. One of the major TXM challenges, due to its nanometre-scale resolution, is the overall instrument stability during the acquisition of the series of tomographic projections. The ability to correct for vertical and horizontal distortions of each projection image during acquisition is necessary in order to achieve the effective 3D spatial resolution. The effectiveness of such an image alignment is also heavily influenced by the absorption propert...
Source: Journal of Synchrotron Radiation - November 1, 2018 Category: Physics Authors: Larsson, E. G ü rsoy, D. De Carlo, F. Lilleodden, E. Storm, M. Wilde, F. Hu, K. M ü ller, M. Greving, I. Tags: full-field transmission X-ray microscopy TXM 3D test pattern nanoporous gold sample-stage movement realignment of projections research papers Source Type: research

Dynamic adaptive X-ray optics. Part II. High-speed piezoelectric bimorph deformable Kirkpatrick – Baez mirrors for rapid variation of the 2D size and shape of X-ray beams
The tangential curvature of actively bent X-ray mirrors at synchrotron radiation and X-ray free-electron laser (XFEL) facilities is typically only changed every few hours or even days. This operation can take tens of minutes for active optics with multiple bending actuators and often requires expert guidance using in situ monitoring devices. Hence, the dynamic performance of active X-ray optics for synchrotron beamlines has historically not been exploited. This is in stark contrast to many other scientific fields. However, many areas of synchrotron radiation and XFEL science, including macromolecular crystallography, could...
Source: Journal of Synchrotron Radiation - November 1, 2018 Category: Physics Authors: Alcock, S.G. Nistea, I.-T. Signorato, R. Owen, R.L. Axford, D. Sutter, J.P. Foster, A. Sawhney, K. Tags: adaptive X-ray optics deformable piezoelectric bimorph mirrors high-voltage bipolar power supplies Kirkpatrick – Baez mirrors Fizeau interferometry research papers Source Type: research

Dynamic adaptive X-ray optics. Part I. Time-resolved optical metrology investigation of the bending behaviour of piezoelectric bimorph deformable X-ray mirrors
Piezoelectric bimorph deformable mirrors (`bimorphs') are routinely used on many synchrotron and free-electron laser beamlines to provide active variation in the size and shape of the X-ray beam. However, the time-domain potential of such optics has never been fully exploited. For the first time, the fast dynamic bending response of bimorphs is investigated here using Fizeau interferometry. Automated scripts for acquisition and analysis were developed to collect Fizeau data at a rate of 0.1   Hz to record dynamic changes in the optical surface as voltages were applied to the electrodes of the piezoelectric actuators. It ...
Source: Journal of Synchrotron Radiation - November 1, 2018 Category: Physics Authors: Alcock, S.G. Nistea, I.-T. Signorato, R. Sawhney, K. Tags: adaptive X-ray optics piezoelectric bimorph deformable mirrors Fizeau interferometry high-voltage power supplies strain-free holders research papers Source Type: research

Quantification of propagating and standing surface acoustic waves by stroboscopic X-ray photoemission electron microscopy
The quantification of surface acoustic waves (SAWs) in LiNbO3 piezoelectric crystals by stroboscopic X-ray photoemission electron microscopy (XPEEM), with a temporal smearing below 80   ps and a spatial resolution below 100   nm, is reported. The contrast mechanism is the varying piezoelectric surface potential associated with the SAW phase. Thus, kinetic energy spectra of photoemitted secondary electrons measure directly the SAW electrical amplitude and allow for the quantification of the associated strain. The stroboscopic imaging combined with a deliberate detuning allows resolving and quantifying the respective sta...
Source: Journal of Synchrotron Radiation - November 1, 2018 Category: Physics Authors: Foerster, M. Statuto, N. Casals, B. Hern á ndez-M í nguez, A. Finizio, S. Mandziak, A. Aballe, L. Hern à ndez Ferr à s, J.M. Maci à , F. Tags: surface acoustic waves (SAWs) LiNbO3 standing and propagating SAW stroboscopic XPEEM LEEM research papers Source Type: research

Observation of the shock-induced β -Sn to b.c.t.-Sn transition using time-resolved X-ray diffraction
Time-resolved X-ray diffraction measurements have been carried out on dynamically compressed Sn up to a maximum pressure of ∼ 13   GPa at the European Synchrotron Radiation Facility. The phase transition from β -Sn to body-centered tetragonal (b.c.t.) Sn has been observed using synchrotron X-ray diffraction for the first time undergoing shock compression and release. Following maximum compression, the sample releases to lower pressures for several nanoseconds until the reverse transition occurs. The data are in good agreement with previous shock boundaries that indicate that the β -Sn phase is stable ∼ ...
Source: Journal of Synchrotron Radiation - November 1, 2018 Category: Physics Authors: Briggs, R. Torchio, R. Sollier, A. Occelli, F. Videau, L. Kretzschmar, N. Wulff, M. Tags: time-resolved X-ray diffraction shock compression phase boundaries research papers Source Type: research

VMXi: a fully automated, fully remote, high-flux in   situ macromolecular crystallography beamline
VMXi is a new high-flux microfocus macromolecular crystallography beamline at Diamond Light Source. The beamline, dedicated to fully automated and fully remote data collection of macromolecular crystals in situ, allows rapid screening of hundreds of crystallization plates from multiple user groups. Its main purpose is to give fast feedback at the complex stages of crystallization and crystal optimization, but it also enables data collection of small and delicate samples that are particularly difficult to harvest using conventional cryo-methods, crystals grown in the lipidic cubic phase, and allows for multi-crystal data co...
Source: Journal of Synchrotron Radiation - November 1, 2018 Category: Physics Authors: Sanchez-Weatherby, J. Sandy, J. Mikolajek, H. Lobley, C.M.C. Mazzorana, M. Kelly, J. Preece, G. Littlewood, R. S ø rensen, T.L.-M. Tags: room-temperature data collection in situ diffraction experiments automated beamline operation serial crystallography beamlines Source Type: research

In situ semi-quantitative analysis of zinc dissolution within nanoporous silicon by X-ray absorption fine-structure spectroscopy employing an X-ray compatible cell
The in situ study of the discharge process in a zinc-based half-cell employing a porous electrode as a structural scaffold is reported. The in situ characterization has been performed by synchrotron X-ray absorption fine-structure spectroscopy and, for this purpose, an inexpensive, simple and versatile electrochemical cell compatible with X-ray experiments has been designed and described. The experimental results reported here have been employed to semi-quantify the dissolved and undissolved zinc species during the discharge, allowing the cell feasibility to be tested and to better understand the functioning of the zinc ha...
Source: Journal of Synchrotron Radiation - November 1, 2018 Category: Physics Authors: Mu ñ oz-Noval, Á . Fukami, K. Koyama, A. Kuruma, T. Hayakawa, S. Tags: zinc negative electrodes in situ XAFS cell porous electrodes research papers Source Type: research

Systematic study of a corrugated waveguide as a microwave undulator
Microwave undulators have great potential to be used in short-wavelength free-electron lasers. In this paper, the properties of a corrugated waveguide and its performance as an undulator cavity for a UK X-ray free-electron laser were systematically studied. The equations presented in this paper allow a fast estimation of the dimensions of the corrugated waveguide. An undulator cavity operating at 36   GHz designed for the HE11 and HE12 modes was investigated and the performance of both modes compared. (Source: Journal of Synchrotron Radiation)
Source: Journal of Synchrotron Radiation - November 1, 2018 Category: Physics Authors: Zhang, L. He, W. Clarke, J. Ronald, K. Phelps, A.D.R. Cross, A. Tags: microwave undulator free-electron laser corrugated waveguide balanced hybrid condition research papers Source Type: research

Live-pig-airway surface imaging and whole-pig CT at the Australian Synchrotron Imaging and Medical Beamline
This study extends the ex vivo sheep and pig tracheal-tissue studies previously performed by the authors at the IMBL. In the present study, attempts were made to determine whether the design of the IMBL is suitable for imaging tracheal MCT in live pigs. The movement of 200   µ m-diameter high-refractive-index (HRI) glass-bead marker particles deposited onto the tracheal airway surface of eight live piglets was tracked and quantified and the MCT response to aerosol delivery was examined. A high-resolution computed tomographic (CT) whole-animal post-mortem scan of one pig was also performed to verify the large sample...
Source: Journal of Synchrotron Radiation - November 1, 2018 Category: Physics Authors: Donnelley, M. Morgan, K.S. Gradl, R. Klein, M. Hausermann, D. Hall, C. Maksimenko, A. Parsons, D.W. Tags: pig live-animal imaging mucociliary transit computed tomography cystic fibrosis IMBL research papers Source Type: research

A water-cooled monochromator for the B16 Test beamline at the Diamond Light Source: capabilities and performance characterization
Systematic studies of the performance of a water-cooled X-ray monochromator, designed and built for the B16 Test beamline at the Diamond Light Source, UK, are presented. A technical description of the monochromator is given and the results of commissioning measurements are discussed. Overall, the monochromator satisfies the original specifications well and meets all the major requirements of the versatile beamline. Following its successful implementation on B16, the basic monochromator design has been reproduced and adapted on other Diamond Light Source beamlines, including B18 and B21. (Source: Journal of Synchrotron Radiation)
Source: Journal of Synchrotron Radiation - November 1, 2018 Category: Physics Authors: Dolbnya, I.P. Sawhney, K.J.S. Scott, S.M. Dent, A.J. Cibin, G. Preece, G.M. Pedersen, U.K. Kelly, J. Murray, P. Tags: X-ray optics X-ray monochromators synchrotron radiation beamlines Source Type: research

Proposal of X-ray absorption spectroscopy and magnetic circular dichroism using broadband free-electron lasers
X-ray free-electron lasers (XFELs) have been widely used for applications such as X-ray crystallography and magnetic spin probes because of their unprecedented performance. Recently, time-resolved X-ray magnetic circular dichroism (XMCD) with ultrafast XFEL pulses have made it possible to achieve an instantaneous view of atomic de-excitation. However, owing to the narrow bandwidth and coherence of XFELs, X-ray absorption spectroscopy (XAS) and XMCD are time- and effort-consuming for both machine scientists and users of XFELs. In this work, an efficient scheme using a broadband XFEL pulse and single-shot X-ray spectrometer ...
Source: Journal of Synchrotron Radiation - November 1, 2018 Category: Physics Authors: Deng, B. Yan, J. Zhang, Q. Sang, Y. Deng, H. Tags: free-electron laser X-ray magnetic circular dichroism research papers Source Type: research

Investigation of `glitches' in the energy spectrum induced by single-crystal diamond compound X-ray refractive lenses
Single-crystal diamond stands out among all the candidate materials that could be exploited to fabricate compound refractive lenses (CRLs) owing to its extremely stable properties. Among all related experimental features, beam divergence, χ -angles relative to the incoming beam in Eulerian geometry and different positions of the X-ray beam relative to the lens geometry may influence the transmission energy spectrum of CRLs. In addition, the orientation of the single-crystal diamond sample may also affect the glitches significantly. To verify these initial assumptions, two experiments, an energy scan and an ω -sca...
Source: Journal of Synchrotron Radiation - November 1, 2018 Category: Physics Authors: Zhang, Q. Polikarpov, M. Klimova, N. Larsen, H.B. Mathiesen, R. Emerich, H. Thorkildsen, G. Snigireva, I. Snigirev, A. Tags: single-crystal diamond CRLs glitches transmission spectrum orientation matrix (UB matrix) research papers Source Type: research

Multi-element X-ray movie imaging with a visible-light CMOS camera
For many years, X-ray movies have been considered a promising tool for exploring and providing insights into chemical reactions. A simultaneous multi-element X-ray movie can further clarify the behavior difference of various elements and help investigate their interactions. The present short communication illustrates how to conduct multi-element X-ray movie imaging in a synchrotron facility solely by placing a micro-pinhole in front of a visible-light complementary metal-oxide semiconductor (CMOS) camera. It has been found that the CMOS camera can resolve X-ray fluorescence spectra when it is specially operated. In this wo...
Source: Journal of Synchrotron Radiation - November 1, 2018 Category: Physics Authors: Zhao, W. Sakurai, K. Tags: multi-element X-ray movie imaging CMOS camera short communications Source Type: research

Fast inside-source X-ray fluorescent holography
Atomic resolution X-ray holography can be realized by using the atoms of the sample as inside sources or inside detectors. However, until now there were only very few experiments in which the atoms played the role of inside sources. The reason is twofold: (i) technically, inside-detector experiments are much easier and faster; (ii) by using atoms as inside detectors one can measure holograms at many energies on the same sample, which helps the reconstruction. This paper shows that, using new technical developments, inside-source holograms can be taken much faster than inside-detector holograms and, by applying a sophistica...
Source: Journal of Synchrotron Radiation - November 1, 2018 Category: Physics Authors: Bortel, G. Faigel, G. Tegze, M. Angelov, B. Tags: X-ray holography inside-source holography X-ray free-electron laser research papers Source Type: research

Synchrotron radiation loss of a laser accelerator based on an inverse electron cyclotron resonance maser
A laser accelerator based on an electron cyclotron resonance maser is described. Important losses that give rise to saturation length and saturation power are included in the analysis. The results are compared with results from an inverse free-electron laser accelerator. (Source: Journal of Synchrotron Radiation)
Source: Journal of Synchrotron Radiation - October 31, 2018 Category: Physics Authors: Khullar, R. Mishra, G. Tags: IFEL undulator research papers Source Type: research

Counting-loss correction for X-ray spectra using the pulse-repairing method
Facing the technical problem of pulse distortion caused by frequent resetting in the latest high-performance silicon drift detectors, which work under high-counting-rate conditions, a method has been used to remove false peaks in order to obtain a precise X-ray spectrum, the essence of which eliminates distorted pulses. Aiming at solving the problem of counting-loss generated by eliminating distorted pulses, this paper proposes an improved method of pulse repairing. A 238Pu source with activity of 10   mCi was used as the measurement object, and the energy spectrum obtained by the pulse repairing method was compared with...
Source: Journal of Synchrotron Radiation - October 31, 2018 Category: Physics Authors: Tang, L. Zhou, J. Fang, F. Yu, J. Hong, X. Liao, X. Zhou, C. Yu, S. Tags: counting-loss correction fast SDD pulse repairing peak area X-ray spectrum research papers Source Type: research

The wave optical whole process design of the soft X-ray interference lithography beamline at SSRF
A new spatially coherent beamline has been designed and constructed at the Shanghai Synchrotron Radiation Facility. Here, the design of the beamline is introduced and the spatial coherence is analyzed throughout the whole process by wave optics. The simulation results show good spatial coherence at the endstation and have been proven by experiment results. (Source: Journal of Synchrotron Radiation)
Source: Journal of Synchrotron Radiation - October 26, 2018 Category: Physics Authors: Xue, C. Meng, X. Wu, Y. Wang, Y. Wang, L. Yang, S. Zhao, J. Tai, R. Tags: synchrotron radiation soft X-ray interference lithography beamline spatial coherence wave optics mutual optical intensity beamlines Source Type: research

On the wave zone of synchrotron radiation
The extension of the wave zone of synchrotron radiation is studied. (Source: Journal of Synchrotron Radiation)
Source: Journal of Synchrotron Radiation - October 26, 2018 Category: Physics Authors: Bagrov, V.G. Tags: wave zone synchrotron radiation research papers Source Type: research

Subpixel resolution in CdTe Timepix3 pixel detectors
Timepix3 (256 × 256 pixels with a pitch of 55   µ m) is a hybrid-pixel-detector readout chip that implements a data-driven architecture and is capable of simultaneous time-of-arrival (ToA) and energy (ToT: time-over-threshold) measurements. The ToA information allows the unambiguous identification of pixel clusters belonging to the same X-ray interaction, which allows for full one-by-one detection of photons. The weighted mean of the pixel clusters can be used to measure the subpixel position of an X-ray interaction. An experiment was performed at the European Synchrotron Radiation Facility in Grenoble, Franc...
Source: Journal of Synchrotron Radiation - October 26, 2018 Category: Physics Authors: Khalil, M. Dreier, E.S. Kehres, J. Jakubek, J. Olsen, U.L. Tags: charge sharing hybrid pixel spectral detectors CdTe X-ray detectors subpixel spatial resolution research papers Source Type: research

In situ observation of phase changes of a silica-supported cobalt catalyst for the Fischer – Tropsch process by the development of a synchrotron-compatible in   situ/operando powder X-ray diffraction cell
In situ characterization of catalysts gives direct insight into the working state of the material. Here, the design and performance characteristics of a universal in   situ synchrotron-compatible X-ray diffraction cell capable of operation at high temperature and high pressure, 1373   K, and 35   bar, respectively, are reported. Its performance is demonstrated by characterizing a cobalt-based catalyst used in a prototypical high-pressure catalytic reaction, the Fischer – Tropsch synthesis, using X-ray diffraction. Cobalt nanoparticles supported on silica were studied in   situ during Fischer – Tro...
Source: Journal of Synchrotron Radiation - October 26, 2018 Category: Physics Authors: Hoffman, A.S. Singh, J.A. Bent, S.F. Bare, S.R. Tags: synchrotron X-ray diffraction Fischer – Tropsch catalysis research papers Source Type: research

Towards chemically neutral carbon cleaning processes: plasma cleaning of Ni, Rh and Al reflective optical coatings and thin Al filters for free-electron lasers and synchrotron beamline applications
The choice of a reflective optical coating or filter material has to be adapted to the intended field of application. This is mainly determined by the required photon energy range or by the required reflection angle. Among various materials, nickel and rhodium are common materials used as reflective coatings for (soft) X-ray mirrors. Similarly, aluminium is one of the most commonly used materials for extreme ultraviolet and soft X-ray transmission filters. However, both of these types of optics are subject to carbon contamination, which can be increasingly problematic for the operation of the high-performance free-electron...
Source: Journal of Synchrotron Radiation - October 25, 2018 Category: Physics Authors: Moreno Fern á ndez, H. Zangrando, M. Sauthier, G. Go ñ i, A.R. Carlino, V. Pellegrin, E. Tags: carbon contamination FEL and synchrotron radiation beamline optics free-electron lasers (FELs) plasma cleaning chemistry inductively coupled plasma research papers Source Type: research

Feasibility study of phase-contrast X-ray laminography using X-ray interferometry
For fine observation of laminar samples, phase-contrast X-ray laminography using X-ray interferometry was developed. An imaging system fitted with a two-crystal X-ray interferometer was used to perform the observations, and the sectional images were calculated by a three-dimensional iterative reconstruction method. Obtained images of an old flat slab of limestone from the Carnic Alps depicted fusulinids in the Carboniferous period with 3   mg   cm − 3 density resolution, and those of carbon paper used for a fuel-cell battery displayed the inner fibrous structures clearly. (Source: Journal of Synchrotron Radiation)
Source: Journal of Synchrotron Radiation - October 25, 2018 Category: Physics Authors: Yoneyama, A. Hyodo, K. Baba, R. Takeya, S. Takeda, T. Tags: X-ray laminography phase-contrast X-ray imaging crystal interferometer research papers Source Type: research

Three-dimensional characterization of the microstructure in rabbit patella – patellar tendon interface using propagation phase-contrast synchrotron radiation microtomography
This study aims to assess the feasibility of propagation phase-contrast synchrotron radiation microtomography (PPC-SR µ CT) for three-dimensional characterization of the microstructure in rabbit patella – patellar tendon interface (PPTI). Based on phase retrieval for PPC-SR µ CT imaging, this technique is capable of visualizing the three-dimensional internal architecture of PPTI at a cellular high spatial resolution including bone and tendon, especially the chondrocytes lacuna at the fibrocartilage layer. The features on the PPC-SR µ CT image of the PPTI are similar to those of a histological sectio...
Source: Journal of Synchrotron Radiation - October 25, 2018 Category: Physics Authors: Zhou, Y. Hu, J. Zhou, J. Zeng, Z. Cao, Y. Wang, Z. Chen, C. Zheng, C. Chen, H. Lu, H. Tags: patella – patellar tendon interface fibrocartilage layer PPC-SR µ CT 3D chondrocytes cell research papers Source Type: research

Laser-heating system for high-pressure X-ray diffraction at the Extreme Conditions beamline I15 at Diamond Light Source
In this article, the specification and application of the new double-sided YAG laser-heating system built on beamline I15 at Diamond Light Source are presented. This system, combined with diamond anvil cell and X-ray diffraction techniques, allows in situ and ex situ characterization of material properties at extremes of pressure and temperature. In order to demonstrate the reliability and stability of this experimental setup over a wide range of pressure and temperature, a case study was performed and the phase diagram of lead was investigated up to 80   GPa and 3300   K. The obtained results agree with previously pub...
Source: Journal of Synchrotron Radiation - October 24, 2018 Category: Physics Authors: Anzellini, S. Kleppe, A.K. Daisenberger, D. Wharmby, M.T. Giampaoli, R. Boccato, S. Baron, M.A. Miozzi, F. Keeble, D.S. Ross, A. Gurney, S. Thompson, J. Knap, G. Booth, M. Hudson, L. Hawkins, D. Walter, M.J. Wilhelm, H. Tags: laser-heated diamond anvil cell X-ray diffraction high pressure and temperature Diamond Light Source beamlines Source Type: research

Towards synchrotron phase-contrast lung imaging in patients – a proof-of-concept study on porcine lungs in a human-scale chest phantom
In-line free propagation phase-contrast synchrotron tomography of the lungs has been shown to provide superior image quality compared with attenuation-based computed tomography (CT) in small-animal studies. The present study was performed to prove the applicability on a human-patient scale using a chest phantom with ventilated fresh porcine lungs. Local areas of interest were imaged with a pixel size of 100   µ m, yielding a high-resolution depiction of anatomical hallmarks of healthy lungs and artificial lung nodules. Details like fine spiculations into surrounding alveolar spaces were shown on a micrometre scale....
Source: Journal of Synchrotron Radiation - October 24, 2018 Category: Physics Authors: Wagner, W.L. Wuennemann, F. Pacil é , S. Albers, J. Arfelli, F. Dreossi, D. Biederer, J. Konietzke, P. Stiller, W. Wielp ü tz, M.O. Accardo, A. Confalonieri, M. Cova, M. Lotz, J. Alves, F. Kauczor, H.-U. Tromba, G. Dullin, C. Tags: propagation based imaging phase retrieval synchrotron radiation preclinical chest phantom high-resolution porcine lung imaging research papers Source Type: research

Ultra-small-angle X-ray photon correlation spectroscopy using the Eiger detector
Successful implementation of the single-photon-counting Eiger 500k pixel array detector for sub-millisecond X-ray photon correlation spectroscopy (XPCS) measurements in the ultra-small-angle scattering region is reported. The performance is demonstrated by measuring the dynamics of dilute silica colloids in aqueous solvents when the detector is operated at different counter depths, 4, 8 and 12   bit. In the fastest mode involving 4   bit parallel readout, a stable frame rate of 22   kHz is obtained that enabled measurement of intensity – intensity autocorrelation functions with good statistics down to the 50 ...
Source: Journal of Synchrotron Radiation - October 24, 2018 Category: Physics Authors: Zinn, T. Homs, A. Sharpnack, L. Tinti, G. Fr ö jdh, E. Douissard, P.-A. Kocsis, M. M ö ller, J. Chushkin, Y. Narayanan, T. Tags: USAXS XPCS colloid dynamics coherent X-ray scattering research papers Source Type: research

A modified discrete tomography for improving the   reconstruction of unknown multi-gray-level material in the `missing wedge' situation
Full angular rotational projections cannot always be acquired in tomographic reconstructions because of the limited space in the experimental setup, leading to the `missing wedge' situation. In this paper, a recovering `missing wedge' discrete algebraic reconstruction technique algorithm (rmwDART) has been proposed to solve the `missing wedge' problem and improve the quality of the three-dimensional reconstruction without prior knowledge of the material component's number or the material's values. By using oversegmentation, boundary extraction and mathematical morphological operations, `missing wedge' artifact areas can be...
Source: Journal of Synchrotron Radiation - October 24, 2018 Category: Physics Authors: Liu, J. Liang, Z. Guan, Y. Wei, W. Bai, H. Chen, L. Liu, G. Tian, Y. Tags: discrete algebraic reconstruction technique (DART) missing wedge over-segmentation tomography limited-angle research papers Source Type: research

Site occupancy of Fe2+, Fe3+ and Ti4+ in titanomagnetite determined by valence-difference contrast in synchrotron X-ray resonant scattering
A synchrotron X-ray diffraction study of a single crystal of titanomagnetite shows that the cation distribution of Fe2+, Fe3+ and Ti4+ is of the inverse-spinel type. The valence-difference contrast (VDC) method of resonant scattering was applied at a wavelength of λ = 1.7441   Å (E = 7.1085   keV) within the pre-edge of the Fe K absorption spectrum, utilizing the large difference in the real part of anomalous scattering factors, between − 7.45 and − 6.50, for Fe2+ and Fe3+, respectively. The most plausible atomic arrangement in Ti0.31Fe2.69O4 obtained from our analysis is [Fe3+1.00]A[Fe3+0.38Fe...
Source: Journal of Synchrotron Radiation - October 23, 2018 Category: Physics Authors: Okube, M. Oshiumi, T. Nagase, T. Miyawaki, R. Yoshiasa, A. Sasaki, S. Sugiyama, K. Tags: resonant scattering anomalous scattering valence-difference contrast titanomagnetite single-crystal X-ray diffraction Fe K absorption edge research papers Source Type: research

XAS/DRIFTS/MS spectroscopy for time-resolved operando investigations at high temperature
The combination of complementary techniques in the characterization of catalysts under working conditions is a very powerful tool for an accurate and in-depth comprehension of the system investigated. In particular, X-ray absorption spectroscopy (XAS) coupled with diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) and mass spectroscopy (MS) is a powerful combination since XAS characterizes the main elements of the catalytic system (selecting the absorption edge) and DRIFTS monitors surface adsorbates while MS enables product identification and quantification. In the present manuscript, a new reactor cell ...
Source: Journal of Synchrotron Radiation - October 23, 2018 Category: Physics Authors: Agostini, G. Meira, D. Monte, M. Vitoux, H. Iglesias-Juez, A. Fern á ndez-Garc í a, M. Mathon, O. Meunier, F. Berruyer, G. Perrin, F. Pasternak, S. Mairs, T. Pascarelli, S. Gorges, B. Tags: combination XAS/DRIFT/MS operando measurements high temperature small-dead-volume cells research papers Source Type: research

Automatic projection image registration for nanoscale X-ray tomographic reconstruction
Novel developments in X-ray sources, optics and detectors have significantly advanced the capability of X-ray microscopy at the nanoscale. Depending on the imaging modality and the photon energy, state-of-the-art X-ray microscopes are routinely operated at a spatial resolution of tens of nanometres for hard X-rays or ∼ 10   nm for soft X-rays. The improvement in spatial resolution, however, has led to challenges in the tomographic reconstruction due to the fact that the imperfections of the mechanical system become clearly detectable in the projection images. Without proper registration of the projection images, a se...
Source: Journal of Synchrotron Radiation - October 23, 2018 Category: Physics Authors: Yu, H. Xia, S. Wei, C. Mao, Y. Larsson, D. Xiao, X. Pianetta, P. Yu, Y.-S. Liu, Y. Tags: transmission X-ray microscopy nanoscale tomography image registration tomographic reconstruction research papers Source Type: research

Phosphorus K-edge XANES spectroscopy has probably often underestimated iron oxyhydroxide-bound P in soils
Phosphorus (P) K-edge X-ray absorption near-edge structure (XANES) spectra of orthophosphate (oPO4) bound to soil FeIII minerals (e.g. ferrihydrite, goethite) show a pre-edge signal at 2148 – 2152   eV. It is unknown whether organic P bound to FeIII oxyhydroxides also show this feature. Otherwise, Fe-bound soil P may be underestimated by P K-edge XANES spectroscopy, because a large portion of Fe oxyhydroxide-bound P in soils is organic P. K-edge XANES spectra were obtained for different organic P compounds present in soils [inositol hexaphosphate (IHP), glucose-6-phosphate (G6P), adenosine triphosphate (ATP)] after...
Source: Journal of Synchrotron Radiation - October 22, 2018 Category: Physics Authors: Prietzel, J. Klysubun, W. Tags: Fe-bound P ferrihydrite goethite organic P P retention P speciation soil IHP LCF K-edge XANES spectra research papers Source Type: research

Diffraction apparatus and procedure in tomography X-ray diffraction imaging for biological cells at cryogenic temperature using synchrotron X-ray radiation
In this study a new cryogenic pot, suitable for tomography experiments, has been developed. The pot can rotate a biological cell over an angular range of ± 170 ° against the direction of the incident X-ray beam. Herein, the details and the performance of the pot and miscellaneous devices are reported, along with established experimental procedures including specimen preparation. The apparatus has been used in tomography experiments for visualizing the three-dimensional structure of a Cyanidioschyzon merolae cell with an approximate size of 5   µ m at a resolution of 136   nm. Based on the experimental ...
Source: Journal of Synchrotron Radiation - October 22, 2018 Category: Physics Authors: Kobayashi, A. Takayama, Y. Okajima, K. Oide, M. Yamamoto, T. Sekiguchi, Y. Oroguchi, T. Nakasako, M. Kohmura, Y. Yamamoto, M. Hoshi, T. Torizuka, Y. Tags: X-ray diffraction imaging tomography biological cells cryogenic experiments research papers Source Type: research

Sirepo: an open-source cloud-based software interface for X-ray source and optics simulations
Sirepo, a browser-based GUI for X-ray source and optics simulations, is presented. Such calculations can be performed using SRW (Synchrotron Radiation Workshop), which is a physical optics computer code, allowing simulation of entire experimental beamlines using the concept of a `virtual beamline' with accurate treatment of synchrotron radiation generation and propagation through the X-ray optical system. SRW is interfaced with Sirepo by means of a Python application programming interface. Sirepo supports most of the optical elements currently used at beamlines, including recent developments in SRW. In particular, support ...
Source: Journal of Synchrotron Radiation - October 19, 2018 Category: Physics Authors: Rakitin, M.S. Moeller, P. Nagler, R. Nash, B. Bruhwiler, D.L. Smalyuk, D. Zhernenkov, M. Chubar, O. Tags: Synchrotron Radiation Workshop (SRW) Sirepo X-ray optics simulations cloud-based software computer programs Source Type: research