Calibration of a compact XUV soft X-ray monochromator with a digital autocollimator in situ
A digital autocollimator of resolution 0.1   µ rad (0.02   arcsec) serves as a handy correction tool for calibrating the angular uncertainty during angular and lateral movements of gratings inside a monochromator chamber under ultra-high vacuum. The photon energy dispersed from the extreme ultraviolet (XUV) to the soft X-ray region of the synchrotron beamline at the Taiwan Light Source was monitored using molecular ionization spectra at high resolution as energy references that correlate with the fine angular steps during grating rotation. The angular resolution of the scanning mechanism was
Source: Journal of Synchrotron Radiation - July 21, 2016 Category: Physics Authors: Yuh, J.-Y. Lin, S.-W. Huang, L.-J. Lee, L.-L. Tags: metrological instrumentation soft X-rays extreme ultraviolet (EUV) diffraction gratings autocollimator on-site beamline diagnistic short communications Source Type: research

Runout error correction in tomographic reconstruction by intensity summation method
An alignment method for correction of the axial and radial runout errors of the rotation stage in X-ray phase-contrast computed tomography has been developed. Only intensity information was used, without extra hardware or complicated calculation. Notably, the method, as demonstrated herein, can utilize the halo artifact to determine displacement. (Source: Journal of Synchrotron Radiation)
Source: Journal of Synchrotron Radiation - July 21, 2016 Category: Physics Authors: Kwon, I.-H. Lim, J. Hong, C.-K. Tags: tomography runout error halo artifact imaging alignment short communications Source Type: research

Vibrational stability of a cryocooled horizontal double-crystal monochromator
The vibrational stability of a horizontally deflecting double-crystal monochromator (HDCM) is investigated. Inherently a HDCM will preserve the vertical beam stability better than a `normal' vertical double-crystal monochromator as the vibrations of a HDCM will almost exclusively affect the horizontal stability. Here both the relative pitch vibration between the first and second crystal and the absolute pitch vibration of the second crystal are measured. All reported measurements are obtained under active cooling by means of flowing liquid nitrogen (LN2). It is found that it is favorable to circulate the LN2 at high pressu...
Source: Journal of Synchrotron Radiation - July 20, 2016 Category: Physics Authors: Kristiansen, P. Johansson, U. Ursby, T. Jensen, B.N. Tags: horizontal double-crystal monochromator vibrational measurements vibrational performance monochromator cryocooling research papers Source Type: research

Current events
(Source: Journal of Synchrotron Radiation)
Source: Journal of Synchrotron Radiation - June 28, 2016 Category: Physics Authors: International Union of Crystallography Tags: current events Source Type: research

Novel silica stabilization method for the analysis of fine nanocrystals using coherent X-ray diffraction imaging
High-energy X-ray Bragg coherent diffraction imaging (BCDI) is a well established synchrotron-based technique used to quantitatively reconstruct the three-dimensional morphology and strain distribution in nanocrystals. The BCDI technique has become a powerful analytical tool for quantitative investigations of nanocrystals, nanotubes, nanorods and more recently biological systems. BCDI has however typically failed for fine nanocrystals in sub-100 nm size regimes – a size routinely achievable by chemical synthesis – despite the spatial resolution of the BCDI technique being 20–30 nm. The limitations of ...
Source: Journal of Synchrotron Radiation - June 22, 2016 Category: Physics Authors: Monteforte, M.Estandarte, A.K.Chen, B.Harder, R.Huang, M.H.Robinson, I.K. Tags: Bragg coherent X-ray diffraction nanocrystals stabilization method three-dimensional reconstruction strain research papers Source Type: research

A method of hard X-ray phase-shifting digital holography
A new method of phase-shifting digital holography is demonstrated in the hard X-ray region. An in-line-type phase-shifting holography setup was installed in a 6.80 keV hard X-ray synchrotron beamline. By placing a phase plate consisting of a hole and a band at the focusing point of a Fresnel lens, the relative phase of the reference and objective beams could be successfully shifted for use with a three-step phase-shift algorithm. The system was verified by measuring the shape of a gold test pattern and a silica sphere. (Source: Journal of Synchrotron Radiation)
Source: Journal of Synchrotron Radiation - June 20, 2016 Category: Physics Authors: Park, S.Y.Hong, C.K.Lim, J. Tags: X-ray imaging phase measurement digital holography phase-shifting microscopy research papers Source Type: research

Third-order nonlinear and linear time-dependent dynamical diffraction of X-rays in crystals
For the first time the third-order nonlinear time-dependent Takagi's equations of X-rays in crystals are obtained and investigated. The third-order nonlinear and linear time-dependent dynamical diffraction of X-rays spatially restricted in the diffraction plane pulses in crystals is investigated theoretically. A method of solving the linear and the third-order nonlinear time-dependent Takagi's equations is proposed. Based on this method, results of analytical and numerical calculations for both linear and nonlinear diffraction cases are presented and compared. (Source: Journal of Synchrotron Radiation)
Source: Journal of Synchrotron Radiation - June 20, 2016 Category: Physics Authors: Balyan, M.K. Tags: third-order nonlinearity time-dependent propagation equations dynamical diffraction X-ray pulse research papers Source Type: research

Synchrotron X-ray CT characterization of titanium parts fabricated by additive manufacturing. Part II. Defects
Synchrotron X-ray tomography (SXRT) has been applied to the study of defects within three-dimensional printed titanium parts. These parts were made using the Arcam EBM® (electron beam melting) process which uses powdered titanium alloy, Ti64 (Ti alloy with approximately 6%Al and 4%V) as the feed and an electron beam for the sintering/welding. The experiment was conducted on the Imaging and Medical Beamline of the Australian Synchrotron. The samples represent a selection of complex shapes with a variety of internal morphologies. Inspection via SXRT has revealed a number of defects which may not otherwise have been seen....
Source: Journal of Synchrotron Radiation - June 17, 2016 Category: Physics Authors: Scarlett, N.V.Y.Tyson, P.Fraser, D.Mayo, S.Maksimenko, A. Tags: additive manufacturing titanium X-ray tomography research papers Source Type: research

A deformation rig for synchrotron microtomography studies of geomaterials under conditions   down to 10   km depth in the Earth
A hard X-ray transparent triaxial deformation apparatus, called HADES, has been developed by Sanchez Technologies and installed on the microtomography beamline ID19 at the European Radiation Synchrotron Facility (ESRF). This rig can be used for time-lapse microtomography studies of the deformation of porous solids (rocks, ceramics, metallic foams) at conditions of confining pressure to 100   MPa, axial stress to 200   MPa, temperature to 250 ° C, and controlled aqueous fluid flow. It is transparent to high-energy X-rays above 60   keV and can be used for in situ studies of coupled processes that involve deformati...
Source: Journal of Synchrotron Radiation - June 16, 2016 Category: Physics Authors: Renard, F. Cordonnier, B. Dysthe, D.K. Boller, E. Tafforeau, P. Rack, A. Tags: microtomography in situ studies porous media hard X-rays short communications Source Type: research

HiSPoD: a program for high-speed polychromatic X-ray diffraction experiments and data analysis on polycrystalline samples
A high-speed X-ray diffraction technique was recently developed at the 32-ID-B beamline of the Advanced Photon Source for studying highly dynamic, yet non-repeatable and irreversible, materials processes. In experiments, the microstructure evolution in a single material event is probed by recording a series of diffraction patterns with extremely short exposure time and high frame rate. Owing to the limited flux in a short pulse and the polychromatic nature of the incident X-rays, analysis of the diffraction data is challenging. Here, HiSPoD, a stand-alone Matlab-based software for analyzing the polychromatic X-ray diffract...
Source: Journal of Synchrotron Radiation - June 16, 2016 Category: Physics Authors: Sun, T.Fezzaa, K. Tags: X-ray diffraction high speed polychromatic beam dynamic processes computer programs Source Type: research

Synchrotron X-ray CT characterization of titanium parts fabricated by additive manufacturing. Part I. Morphology
Synchrotron X-ray tomography has been applied to the study of titanium parts fabricated by additive manufacturing (AM). The AM method employed here was the Arcam EBM® (electron beam melting) process which uses powdered titanium alloy, Ti64 (Ti alloy with approximately 6%Al and 4%V), as the feed and an electron beam for the sintering/welding. The experiment was conducted on the Imaging and Medical Beamline of the Australian Synchrotron. Samples were chosen to examine the effect of build direction and complexity of design on the surface morphology and final dimensions of the piece. (Source: Journal of Synchrotron Radiation)
Source: Journal of Synchrotron Radiation - June 16, 2016 Category: Physics Authors: Scarlett, N.V.Y.Tyson, P.Fraser, D.Mayo, S.Maksimenko, A. Tags: additive manufacturing titanium X-ray tomography research papers Source Type: research

A deformation rig for synchrotron microtomography studies of geomaterials under conditions down to 10 km depth in the Earth
A hard X-ray transparent triaxial deformation apparatus, called HADES, has been developed by Sanchez Technologies and installed on the microtomography beamline ID19 at the European Radiation Synchrotron Facility (ESRF). This rig can be used for time-lapse microtomography studies of the deformation of porous solids (rocks, ceramics, metallic foams) at conditions of confining pressure to 100 MPa, axial stress to 200 MPa, temperature to 250°C, and controlled aqueous fluid flow. It is transparent to high-energy X-rays above 60 keV and can be used for in situ studies of coupled processes that involve deformation and c...
Source: Journal of Synchrotron Radiation - June 16, 2016 Category: Physics Authors: Renard, F.Cordonnier, B.Dysthe, D.K.Boller, E.Tafforeau, P.Rack, A. Tags: microtomography in situ studies porous media hard X-rays short communications Source Type: research

Development of a single-cell X-ray fluorescence flow cytometer
An X-ray fluorescence flow cytometer that can determine the total metal content of single cells has been developed. Capillary action or pressure was used to load cells into hydrophilic or hydrophobic capillaries, respectively. Once loaded, the cells were transported at a fixed vertical velocity past a focused X-ray beam. X-ray fluorescence was then used to determine the mass of metal in each cell. By making single-cell measurements, the population heterogeneity for metals in the µM to mM concentration range on fL sample volumes can be directly measured, a measurement that is difficult using most analytical methods. T...
Source: Journal of Synchrotron Radiation - June 16, 2016 Category: Physics Authors: Crawford, A.M.Kurecka, P.Yim, T.K.Kozemchak, C.Deb, A.Dostál, L.Sun, C.-J.Brewe, D.L.Barrea, R.Penner-Hahn, J.E. Tags: flow cytometry X-ray fluorescence single cell metallome homeostasis research papers Source Type: research

Multi-speckle X-ray photon correlation spectroscopy   in the ultra-small-angle X-ray scattering   range
Multi-speckle X-ray photon correlation spectroscopy (XPCS) measurements in the ultra-small-angle range are performed using a long pinhole collimation instrument in combination with two-dimensional photon-counting and high-sensitivity imaging detectors. The feasibility of the presented setup to measure dynamics on different time and length scales pertinent to colloidal systems is shown. This setup offers new research opportunities, such as for example in the investigation of non-equilibrium dynamics in optically opaque, complex systems over length scales from tens of nanometres to several micrometres. In addition, due to th...
Source: Journal of Synchrotron Radiation - June 14, 2016 Category: Physics Authors: M ö ller, J. Chushkin, Y. Prevost, S. Narayanan, T. Tags: USAXS XPCS research papers Source Type: research

Vanadium K-edge XANES in vanadium-bearing model compounds: a full multiple scattering study
A systematic study is presented on a set of vanadium-bearing model compounds, representative of the most common V coordination geometries and oxidation states, analysed by means of vanadium K-edge X-ray absorption near-edge spectroscopy calculations in the full multiple scattering (FMS) framework. Analysis and calibration of the free parameters of the theory under the muffin-tin approximation (muffin-tin overlap and interstitial potential) have been carried out by fitting the experimental spectra using the MXAN program. The analysis shows a correlation of the fit parameters with the V coordination geometry and oxidation st...
Source: Journal of Synchrotron Radiation - June 14, 2016 Category: Physics Authors: Benzi, F.Giuli, G.Della Longa, S.Paris, E. Tags: full multiple scattering theory V-bearing compounds XANES non-structural parameters research papers Source Type: research

Synchrotron X-ray microfluorescence measurement of metal distributions in Phragmites australis root system in the Yangtze River intertidal zone
This study investigates the distributions of Br, Ca, Cl, Cr, Cu, K, Fe, Mn, Pb, Ti, V and Zn in Phragmites australis root system and the function of Fe nanoparticles in scavenging metals in the root epidermis using synchrotron X-ray microfluorescence, synchrotron transmission X-ray microscope measurement and synchrotron X-ray absorption near-edge structure techniques. The purpose of this study is to understand the mobility of metals in wetland plant root systems after their uptake from rhizosphere soils. Phragmites australis samples were collected in the Yangtze River intertidal zone in July 2013. The results indicate that...
Source: Journal of Synchrotron Radiation - June 14, 2016 Category: Physics Authors: Feng, H.Zhang, W.Qian, Y.Liu, W.Yu, L.Yoo, S.Wang, J.Wang, J.-J.Eng, C.Liu, C.-J.Tappero, R. Tags: Yangtze River intertidal zone metal uptake Phragmites australis Fe nanoparticles research papers Source Type: research

Multi-speckle X-ray photon correlation spectroscopy in the ultra-small-angle X-ray scattering range
Multi-speckle X-ray photon correlation spectroscopy (XPCS) measurements in the ultra-small-angle range are performed using a long pinhole collimation instrument in combination with two-dimensional photon-counting and high-sensitivity imaging detectors. The feasibility of the presented setup to measure dynamics on different time and length scales pertinent to colloidal systems is shown. This setup offers new research opportunities, such as for example in the investigation of non-equilibrium dynamics in optically opaque, complex systems over length scales from tens of nanometres to several micrometres. In addition, due to th...
Source: Journal of Synchrotron Radiation - June 14, 2016 Category: Physics Authors: Möller, J.Chushkin, Y.Prevost, S.Narayanan, T. Tags: USAXS XPCS research papers Source Type: research

Continuous-scan capability at SSRL and applications to X-ray diffraction
Typical X-ray diffraction measurements are made by moving a detector to discrete positions in space and then measuring the signal at each stationary position. This step-scanning method can be time-consuming, and may induce vibrations in the measurement system when the motors are accelerated and decelerated at each position. Furthermore, diffraction information between the data points may be missed unless a fine step-scanning is used, which further increases the total measurement time. To utilize beam time efficiently, the motor acceleration and deceleration time should be minimized, and the signal-to-noise ratio should be ...
Source: Journal of Synchrotron Radiation - June 14, 2016 Category: Physics Authors: Li, C.Kiss, A.M.Van Campen, D.G.Garachtchenko, A.Kolotovsky, Y.Stone, K.Xu, Y.Zhang, W.Corbett, J. Tags: continuous scan step scan X-ray diffraction efficiency research papers Source Type: research

Optimization of tomographic reconstruction workflows on geographically distributed resources
New technological advancements in synchrotron light sources enable data acquisitions at unprecedented levels. This emergent trend affects not only the size of the generated data but also the need for larger computational resources. Although beamline scientists and users have access to local computational resources, these are typically limited and can result in extended execution times. Applications that are based on iterative processing as in tomographic reconstruction methods require high-performance compute clusters for timely analysis of data. Here, time-sensitive analysis and processing of Advanced Photon Source data o...
Source: Journal of Synchrotron Radiation - June 14, 2016 Category: Physics Authors: Bicer, T.Gürsoy, D.Kettimuthu, R.De Carlo, F.Foster, I.T. Tags: tomography scientific workflows performance modeling research papers Source Type: research

X-ray nanotomography and focused-ion-beam sectioning for quantitative three-dimensional analysis of nanocomposites
Knowing the relationship between three-dimensional structure and properties is paramount for complete understanding of material behavior. In this work, the internal nanostructure of micrometer-size (∼10 µm) composite Ni/Al particles was analyzed using two different approaches. The first technique, synchrotron-based X-ray nanotomography, is a nondestructive method that can attain resolutions of tens of nanometers. The second is a destructive technique with sub-nanometer resolution utilizing scanning electron microscopy combined with an ion beam and `slice and view' analysis, where the sample is repeatedly milled...
Source: Journal of Synchrotron Radiation - June 14, 2016 Category: Physics Authors: Shuck, C.E.Frazee, M.Gillman, A.Beason, M.T.Gunduz, I.E.Matouš, K.Winarski, R.Mukasyan, A.S. Tags: X-ray nanotomography scanning electron microscopy quantitative image analysis three-dimensional reconstruction nanocomposite powder research papers Source Type: research

Collimating Montel mirror as part of a multi-crystal analyzer system for resonant inelastic X-ray scattering
Advances in resonant inelastic X-ray scattering (RIXS) have come in lockstep with improvements in energy resolution. Currently, the best energy resolution at the Ir L3-edge stands at ∼25 meV, which is achieved using a diced Si(844) spherical crystal analyzer. However, spherical analyzers are limited by their intrinsic reflection width. A novel analyzer system using multiple flat crystals provides a promising way to overcome this limitation. For the present design, an energy resolution at or below 10 meV was selected. Recognizing that the angular acceptance of flat crystals is severely limited, a collimating element...
Source: Journal of Synchrotron Radiation - May 31, 2016 Category: Physics Authors: Kim, J.Shi, X.Casa, D.Qian, J.Huang, X.Gog, T. Tags: X-ray optics multilayer mirror X-ray collimation resonant inelastic X-ray scattering research papers Source Type: research

Specimen preparation for cryogenic coherent X-ray diffraction imaging of biological cells and cellular organelles by using the X-ray free-electron laser at SACLA
Coherent X-ray diffraction imaging (CXDI) allows internal structures of biological cells and cellular organelles to be analyzed. CXDI experiments have been conducted at 66 K for frozen-hydrated biological specimens at the SPring-8 Angstrom Compact Free-Electron Laser facility (SACLA). In these cryogenic CXDI experiments using X-ray free-electron laser (XFEL) pulses, specimen particles dispersed on thin membranes of specimen disks are transferred into the vacuum chamber of a diffraction apparatus. Because focused single XFEL pulses destroy specimen particles at the atomic level, diffraction patterns are collected through ...
Source: Journal of Synchrotron Radiation - May 30, 2016 Category: Physics Authors: Kobayashi, A.Sekiguchi, Y.Oroguchi, T.Okajima, K.Fukuda, A.Oide, M.Yamamoto, M.Nakasako, M. Tags: coherent X-ray diffraction imaging X-ray free-electron laser frozen-hydrated non-crystalline specimens cryogenic X-ray diffraction experiment structures of cells and cellular organelles research papers Source Type: research

The high-resolution absorption spectroscopy branch on the VUV beamline DESIRS at SOLEIL
A VUV absorption spectroscopy facility designed for ultra-high spectral resolution is in operation as a dedicated branch on the DESIRS beamline at Synchrotron SOLEIL. This branch includes a unique VUV Fourier transform spectrometer (FTS) and a dedicated versatile gas sample chamber. The FTS instrument can cover a large UV–VUV spectral range from 4 to 30 eV, with an ultimate line width of 0.08 cm−1 on a large spectral window, ΔE/E = 7%, over which all spectral features can be acquired in a multiplex way. The performance can be considered to be a middle ground between broadband moderate-resolution spect...
Source: Journal of Synchrotron Radiation - May 26, 2016 Category: Physics Authors: Oliveira, N. deJoyeux, D.Roudjane, M.Gil, J.-F.Pilette, B.Archer, L.Ito, K.Nahon, L. Tags: VUV beamline Fourier spectroscopy absorption spectroscopy high spectral resolution research papers Source Type: research

The vacuum ultraviolet beamline/endstations at   NSRL dedicated to combustion research
An undulator-based vacuum ultraviolet (VUV) beamline (BL03U), intended for combustion chemistry studies, has been constructed at the National Synchrotron Radiation Laboratory (NSRL) in Hefei, China. The beamline is connected to the newly upgraded Hefei Light Source (HLS   II), and could deliver photons in the 5 – 21   eV range, with a photon flux of 1013   photons   s − 1 at 10   eV when the beam current is 300   mA. The monochromator of the beamline is equipped with two gratings (200   lines mm − 1 and 400   lines mm − 1) and its resolving power is 3900 at 7.3   eV for the 200  ...
Source: Journal of Synchrotron Radiation - May 15, 2016 Category: Physics Authors: Zhou, Z. Du, X. Yang, J. Wang, Y. Li, C. Wei, S. Du, L. Li, Y. Qi, F. Wang, Q. Tags: VUV beamline combustion premixed flame flow reactor beamlines Source Type: research

The vacuum ultraviolet beamline/endstations at NSRL dedicated to combustion research
An undulator-based vacuum ultraviolet (VUV) beamline (BL03U), intended for combustion chemistry studies, has been constructed at the National Synchrotron Radiation Laboratory (NSRL) in Hefei, China. The beamline is connected to the newly upgraded Hefei Light Source (HLS II), and could deliver photons in the 5–21 eV range, with a photon flux of 1013 photons s−1 at 10 eV when the beam current is 300 mA. The monochromator of the beamline is equipped with two gratings (200 lines mm−1 and 400 lines mm−1) and its resolving power is 3900 at 7.3 eV for the 200 lines mm−1 grating an...
Source: Journal of Synchrotron Radiation - May 15, 2016 Category: Physics Authors: Zhou, Z.Du, X.Yang, J.Wang, Y.Li, C.Wei, S.Du, L.Li, Y.Qi, F.Wang, Q. Tags: VUV beamline combustion premixed flame flow reactor beamlines Source Type: research

Two-color operation of a free-electron laser with a tilted beam
With the successful operation of free-electron lasers (FELs) as user facilities there has been a growing demand for experiments with two photon pulses with variable photon energy and time separation. A configuration of an undulator with variable-gap control and a delaying chicane in the middle of the beamline is proposed. An injected electron beam with a transverse tilt will only yield FEL radiation for the parts which are close to the undulator axis. This allows, after re-aligning and delaying the electron beam, a different part of the bunch to be used to produce a second FEL pulse. This method offers independent control ...
Source: Journal of Synchrotron Radiation - May 15, 2016 Category: Physics Authors: Reiche, S.Prat, E. Tags: free-electron laser undulator beamline design simulations research papers Source Type: research

Undulator beamline optimization with integrated chicanes for X-ray free-electron-laser facilities
An optimization of the undulator layout of X-ray free-electron-laser (FEL) facilities based on placing small chicanes between the undulator modules is presented. The installation of magnetic chicanes offers the following benefits with respect to state-of-the-art FEL facilities: reduction of the required undulator length to achieve FEL saturation, improvement of the longitudinal coherence of the FEL pulses, and the ability to produce shorter FEL pulses with higher power levels. Numerical simulations performed for the soft X-ray beamline of the SwissFEL facility show that optimizing the advantages of the layout requires shor...
Source: Journal of Synchrotron Radiation - May 15, 2016 Category: Physics Authors: Prat, E.Calvi, M.Ganter, R.Reiche, S.Schietinger, T.Schmidt, T. Tags: free-electron laser undulator beamline design simulations research papers Source Type: research

Characterization of an X-ray mirror mechanical bender for the European XFEL
One of the classical devices used to tune a mirror on an X-ray optical setup is a mechanical bender. This is often designed in such a way that the mirror is held with clamps on both ends; a motor is then used to put a torque on the clamps, inducing a cylindrical shape of the mirror surface. A mechanical bender with this design was recently characterized, to bend a 950 mm-long mirror up to a radius of curvature of 10 km. The characterization was performed using a large-aperture Fizeau interferometer with an angled incidence setup. Some particular and critical effects were investigated, such as calibration, hysteresis, t...
Source: Journal of Synchrotron Radiation - May 15, 2016 Category: Physics Authors: Vannoni, M.Freijo Martín, I.Sinn, H. Tags: bendable mirror X-ray optics active optics metrology research papers Source Type: research

Visualization of mouse spinal cord intramedullary arteries using phase- and attenuation-contrast tomographic imaging
In this study, an imaging method is proposed and the potential of phase-contrast imaging (PCI)- and attenuation-contrast imaging (ACI)-based synchrotron radiation for high-resolution tomography of intramedullary arteries in mouse spinal cord is validated. The three-dimensional vessel morphology, particularly that of the central sulcus arteries (CSA), detected with these two imaging models was quantitatively analyzed and compared. It was determined that both PCI- and ACI-based synchrotron radiation can be used to visualize the physiological arrangement of the entire intramedullary artery network in the mouse spinal cord in ...
Source: Journal of Synchrotron Radiation - May 15, 2016 Category: Physics Authors: Cao, Y.Yin, X.Zhang, J.Wu, T.Li, D.Lu, H.Hu, J. Tags: intramedullary arteries phase-contrast imaging attenuation-contrast imaging high resolution research papers Source Type: research

Guiding synchrotron X-ray diffraction by multimodal video-rate protein crystal imaging
Synchronous digitization, in which an optical sensor is probed synchronously with the firing of an ultrafast laser, was integrated into an optical imaging station for macromolecular crystal positioning prior to synchrotron X-ray diffraction. Using the synchronous digitization instrument, second-harmonic generation, two-photon-excited fluorescence and bright field by laser transmittance were all acquired simultaneously with perfect image registry at up to video-rate (15 frames s−1). A simple change in the incident wavelength enabled simultaneous imaging by two-photon-excited ultraviolet fluorescence, one-photon-ex...
Source: Journal of Synchrotron Radiation - May 15, 2016 Category: Physics Authors: Newman, J.A.Zhang, S.Sullivan, S.Z.Dow, X.Y.Becker, M.Sheedlo, M.J.Stepanov, S.Carlsen, M.S.Everly, R.M.Das, C.Fischetti, R.F.Simpson, G.J. Tags: nonlinear optical microscopy protein crystal synchronous digitization research papers Source Type: research

Generation of ultra-large-bandwidth X-ray free-electron-laser pulses with a transverse-gradient undulator
A new and simple method to generate X-ray free-electron-laser radiation with unprecedented spectral bandwidth above the 10% level is presented. The broad bandwidth is achieved by sending a transversely tilted beam through a transverse-gradient undulator. The extent of the bandwidth can easily be controlled by variation of the beam tilt or the undulator gradient. Numerical simulations confirm the validity and feasibility of this method. (Source: Journal of Synchrotron Radiation)
Source: Journal of Synchrotron Radiation - May 12, 2016 Category: Physics Authors: Prat, E.Calvi, M.Reiche, S. Tags: free-electron laser ultra-large-bandwith X-ray pulses transverse-gradient undulator simulations research papers Source Type: research

Current events
(Source: Journal of Synchrotron Radiation)
Source: Journal of Synchrotron Radiation - April 27, 2016 Category: Physics Authors: International Union of Crystallography Tags: current events Source Type: research

Single-crystal diamond refractive lens for focusing X-rays in two dimensions. Erratum
A correction is made to a citation in the article by Antipov et al. (2016) [J. Synchrotron Rad. 23, 163–168]. (Source: Journal of Synchrotron Radiation)
Source: Journal of Synchrotron Radiation - April 27, 2016 Category: Physics Authors: Antipov, S.Baryshev, S.V.Butler, J.E.Antipova, O.Liu, Z.Stoupin, S. Tags: diamond two-dimensional lens X-ray optics compound refractive lens laser etching addenda and errata Source Type: research

Integration of TomoPy and the ASTRA toolbox for advanced processing and reconstruction of tomographic synchrotron data
The processing of tomographic synchrotron data requires advanced and efficient software to be able to produce accurate results in reasonable time. In this paper, the integration of two software toolboxes, TomoPy and the ASTRA toolbox, which, together, provide a powerful framework for processing tomographic data, is presented. The integration combines the advantages of both toolboxes, such as the user-friendliness and CPU-efficient methods of TomoPy and the flexibility and optimized GPU-based reconstruction methods of the ASTRA toolbox. It is shown that both toolboxes can be easily installed and used together, requiring onl...
Source: Journal of Synchrotron Radiation - April 27, 2016 Category: Physics Authors: Pelt, D.M.Gürsoy, D.Palenstijn, W.J.Sijbers, J.De Carlo, F.Batenburg, K.J. Tags: tomography TomoPy ASTRA toolbox computer programs Source Type: research

Multiple scattering in grazing-incidence X-ray   diffraction: impact on lattice-constant determination   in thin films
This study reveals comparable intensities of the split peaks with a maximum for incidence angles close to the critical angle of total external reflection of the substrate. This observation is rationalized by two different scattering pathways resulting in diffraction peaks at different positions at the detector. In order to minimize the splitting, the data suggest either using incident angles well below the critical angle of total reflection or angles well above, which sufficiently attenuates the contributions from the second scattering path. This study highlights that the refraction of X-rays in (organic) thin films has to...
Source: Journal of Synchrotron Radiation - April 19, 2016 Category: Physics Authors: Resel, R. Bainschab, M. Pichler, A. Dingemans, T. Simbrunner, C. Stangl, J. Salzmann, I. Tags: organic thin films X-ray scattering grazing-incidence diffraction surface reflection X-ray refraction grazing-incidence X-ray diffraction refraction correction research papers Source Type: research

DABAM: an open-source database of X-ray mirrors metrology
An open-source database containing metrology data for X-ray mirrors is presented. It makes available metrology data (mirror heights and slopes profiles) that can be used with simulation tools for calculating the effects of optical surface errors in the performances of an optical instrument, such as a synchrotron beamline. A typical case is the degradation of the intensity profile at the focal position in a beamline due to mirror surface errors. This database for metrology (DABAM) aims to provide to the users of simulation tools the data of real mirrors. The data included in the database are described in this paper, with de...
Source: Journal of Synchrotron Radiation - April 19, 2016 Category: Physics Authors: Sanchez del Rio, M.Bianchi, D.Cocco, D.Glass, M.Idir, M.Metz, J.Raimondi, L.Rebuffi, L.Reininger, R.Shi, X.Siewert, F.Spielmann-Jaeggi, S.Takacs, P.Tomasset, M.Tonnessen, T.Vivo, A.Yashchuk, V. Tags: X-ray mirror metrology database Python statistics research papers Source Type: research

Multiple scattering in grazing-incidence X-ray diffraction: impact on lattice-constant determination in thin films
This study reveals comparable intensities of the split peaks with a maximum for incidence angles close to the critical angle of total external reflection of the substrate. This observation is rationalized by two different scattering pathways resulting in diffraction peaks at different positions at the detector. In order to minimize the splitting, the data suggest either using incident angles well below the critical angle of total reflection or angles well above, which sufficiently attenuates the contributions from the second scattering path. This study highlights that the refraction of X-rays in (organic) thin films has to...
Source: Journal of Synchrotron Radiation - April 19, 2016 Category: Physics Authors: Resel, R.Bainschab, M.Pichler, A.Dingemans, T.Simbrunner, C.Stangl, J.Salzmann, I. Tags: organic thin films X-ray scattering grazing-incidence diffraction surface reflection X-ray refraction grazing-incidence X-ray diffraction refraction correction research papers Source Type: research

A sample cell for in situ electric-field-dependent structural characterization and macroscopic strain measurements
When studying electro-mechanical materials, observing the structural changes during the actuation process is necessary for gaining a complete picture of the structure–property relationship as certain mechanisms may be meta-stable during actuation. In situ diffraction methods offer a powerful and direct means of quantifying the structural contributions to the macroscopic strain of these materials. Here, a sample cell is demonstrated capable of measuring the structural variations of electro-mechanical materials under applied electric potentials up to 10 kV. The cell is designed for use with X-ray scattering technique...
Source: Journal of Synchrotron Radiation - April 19, 2016 Category: Physics Authors: Hossain, M.J.Wang, L.Wang, Z.Khansur, N.H.Hinterstein, M.Kimpton, J.A.Daniels, J.E. Tags: X-ray diffraction strain electro-ceramics piezoelectrics ferroelectrics research papers Source Type: research

Spectrum splitting for fast polarization switching of   undulator radiation
A simple scheme to quickly switch the polarity of circular radiation is proposed, which is based on spectrum splitting of undulator radiation. In this scheme, two helical undulators with opposite helicities are placed tandem in one straight section, both of which are divided into several segments. The optical phases between segments are tuned so that light waves from one of the two undulators are out of phase, while those from the other are in phase. Then the radiation spectrum of the former is split and the intensity at the fundamental photon energy vanishes. As a consequence, the monochromated photon beam at the fundamen...
Source: Journal of Synchrotron Radiation - April 18, 2016 Category: Physics Authors: Kinjo, R. Tanaka, T. Tags: undulator radiation fast polarization switching spectrum-splitting scheme research papers Source Type: research

Submillisecond X-ray photon correlation spectroscopy   from a pixel array detector with fast   dual gating and no readout dead-time
Small-angle scattering X-ray photon correlation spectroscopy (XPCS) studies were performed using a novel photon-counting pixel array detector with dual counters for each pixel. Each counter can be read out independently from the other to ensure there is no readout dead-time between the neighboring frames. A maximum frame rate of 11.8   kHz was achieved. Results on test samples show good agreement with simple diffusion. The potential of extending the time resolution of XPCS beyond the limit set by the detector frame rate using dual counters is also discussed. (Source: Journal of Synchrotron Radiation)
Source: Journal of Synchrotron Radiation - April 18, 2016 Category: Physics Authors: Zhang, Q. Dufresne, E.M. Grybos, P. Kmon, P. Maj, P. Narayanan, S. Deptuch, G.W. Szczygiel, R. Sandy, A. Tags: pixel array detector (PAD) high frame rate photon counting two counters X-ray photon correlation spectroscopy (XPCS) small-angle X-ray scattering (SAXS) research papers Source Type: research

Sapphire hard X-ray Fabry – Perot resonators for synchrotron experiments
Hard X-ray Fabry – Perot resonators (FPRs) made from sapphire crystals were constructed and characterized. The FPRs consisted of two crystal plates, part of a monolithic crystal structure of Al2O3, acting as a pair of mirrors, for the backward reflection (0   0   0   30) of hard X-rays at 14.3147   keV. The dimensional accuracy during manufacturing and the defect density in the crystal in relation to the resonance efficiency of sapphire FPRs were analyzed from a theoretical standpoint based on X-ray cavity resonance and measurements using scanning electron microscopic and X-ray topographic techniques for crys...
Source: Journal of Synchrotron Radiation - April 18, 2016 Category: Physics Authors: Tsai, Y.-W. Wu, Y.-H. Chang, Y.-Y. Liu, W.-C. Liu, H.-L. Chu, C.-H. Chen, P.-C. Lin, P.-T. Fu, C.-C. Chang, S.-L. Tags: sapphire Fabry – Perot resonator coherent X-rays backward diffraction dynamical diffraction high-resolution monochromator research papers Source Type: research

Submillisecond X-ray photon correlation spectroscopy from a pixel array detector with fast dual gating and no readout dead-time
Small-angle scattering X-ray photon correlation spectroscopy (XPCS) studies were performed using a novel photon-counting pixel array detector with dual counters for each pixel. Each counter can be read out independently from the other to ensure there is no readout dead-time between the neighboring frames. A maximum frame rate of 11.8 kHz was achieved. Results on test samples show good agreement with simple diffusion. The potential of extending the time resolution of XPCS beyond the limit set by the detector frame rate using dual counters is also discussed. (Source: Journal of Synchrotron Radiation)
Source: Journal of Synchrotron Radiation - April 18, 2016 Category: Physics Authors: Zhang, Q.Dufresne, E.M.Grybos, P.Kmon, P.Maj, P.Narayanan, S.Deptuch, G.W.Szczygiel, R.Sandy, A. Tags: pixel array detector (PAD) high frame rate photon counting two counters X-ray photon correlation spectroscopy (XPCS) small-angle X-ray scattering (SAXS) research papers Source Type: research

Spectrum splitting for fast polarization switching of undulator radiation
A simple scheme to quickly switch the polarity of circular radiation is proposed, which is based on spectrum splitting of undulator radiation. In this scheme, two helical undulators with opposite helicities are placed tandem in one straight section, both of which are divided into several segments. The optical phases between segments are tuned so that light waves from one of the two undulators are out of phase, while those from the other are in phase. Then the radiation spectrum of the former is split and the intensity at the fundamental photon energy vanishes. As a consequence, the monochromated photon beam at the fundamen...
Source: Journal of Synchrotron Radiation - April 18, 2016 Category: Physics Authors: Kinjo, R.Tanaka, T. Tags: undulator radiation fast polarization switching spectrum-splitting scheme research papers Source Type: research

Sapphire hard X-ray Fabry–Perot resonators for synchrotron experiments
Hard X-ray Fabry–Perot resonators (FPRs) made from sapphire crystals were constructed and characterized. The FPRs consisted of two crystal plates, part of a monolithic crystal structure of Al2O3, acting as a pair of mirrors, for the backward reflection (0 0 0 30) of hard X-rays at 14.3147 keV. The dimensional accuracy during manufacturing and the defect density in the crystal in relation to the resonance efficiency of sapphire FPRs were analyzed from a theoretical standpoint based on X-ray cavity resonance and measurements using scanning electron microscopic and X-ray topographic techniques for crystal defect...
Source: Journal of Synchrotron Radiation - April 18, 2016 Category: Physics Authors: Tsai, Y.-W.Wu, Y.-H.Chang, Y.-Y.Liu, W.-C.Liu, H.-L.Chu, C.-H.Chen, P.-C.Lin, P.-T.Fu, C.-C.Chang, S.-L. Tags: sapphire Fabry – Perot resonator coherent X-rays backward diffraction dynamical diffraction high-resolution monochromator research papers Source Type: research

A Johann-type X-ray emission spectrometer at   the   Rossendorf beamline
This paper gives a detailed description, including equations, of the Johann-type X-ray emission spectrometer which has been recently installed and tested at the Rossendorf beamline (ROBL) of the European Synchrotron Radiation Facility. The spectrometer consists of a single spherically bent crystal analyzer and an avalanche photodiode detector positioned on the vertical Rowland cycle of 1   m diameter. The hard X-ray emission spectrometer ( ∼ 3.5 – 25   keV) operates at atmospheric pressure and covers the Bragg angles of 65 ° – 89 ° . The instrument has been tested at high and intermediate incide...
Source: Journal of Synchrotron Radiation - April 15, 2016 Category: Physics Authors: Kvashnina, K.O. Scheinost, A.C. Tags: X-ray emission spectrometer Johann geometry XANES HERFD XES RIXS actinides beamlines Source Type: research

Amyloid- β plaque deposition measured using propagation-based X-ray phase contrast CT imaging
Amyloid beta accumulation into insoluble plaques (A β p) is known to play a significant role in the pathological process in Alzheimer's disease (AD). The presence of A β p is also one of the neuropathological hallmarks for the disease. AD final diagnosis is generally acknowledged after the evaluation of A β p deposition in the brain. Insoluble A β p accumulation may also concur to cause AD as postulated in the so-called amyloid hypothesis. Therefore, the visualization, evaluation and quantification of A β p are nowadays the keys for a better understanding of the disease, which may point to a possib...
Source: Journal of Synchrotron Radiation - April 15, 2016 Category: Physics Authors: Astolfo, A. Lathuili è re, A. Laversenne, V. Schneider, B. Stampanoni, M. Tags: phase contrast X-ray CT brain imaging amyloid plaques Alzheimer's disease research papers Source Type: research

A Johann-type X-ray emission spectrometer at the Rossendorf beamline
This paper gives a detailed description, including equations, of the Johann-type X-ray emission spectrometer which has been recently installed and tested at the Rossendorf beamline (ROBL) of the European Synchrotron Radiation Facility. The spectrometer consists of a single spherically bent crystal analyzer and an avalanche photodiode detector positioned on the vertical Rowland cycle of 1 m diameter. The hard X-ray emission spectrometer (∼3.5–25 keV) operates at atmospheric pressure and covers the Bragg angles of 65°–89°. The instrument has been tested at high and intermediate incident energies, ...
Source: Journal of Synchrotron Radiation - April 15, 2016 Category: Physics Authors: Kvashnina, K.O.Scheinost, A.C. Tags: X-ray emission spectrometer Johann geometry XANES HERFD XES RIXS actinides beamlines Source Type: research

Amyloid-β plaque deposition measured using propagation-based X-ray phase contrast CT imaging
Amyloid beta accumulation into insoluble plaques (Aβp) is known to play a significant role in the pathological process in Alzheimer's disease (AD). The presence of Aβp is also one of the neuropathological hallmarks for the disease. AD final diagnosis is generally acknowledged after the evaluation of Aβp deposition in the brain. Insoluble Aβp accumulation may also concur to cause AD as postulated in the so-called amyloid hypothesis. Therefore, the visualization, evaluation and quantification of Aβp are nowadays the keys for a better understanding of the disease, which may point to a possible cure fo...
Source: Journal of Synchrotron Radiation - April 15, 2016 Category: Physics Authors: Astolfo, A.Lathuilière, A.Laversenne, V.Schneider, B.Stampanoni, M. Tags: phase contrast X-ray CT brain imaging amyloid plaques Alzheimer's disease research papers Source Type: research

Implementation of ultrafast X-ray diffraction at the 1W2B wiggler beamline of Beijing Synchrotron Radiation Facility
The implementation of a laser pump/X-ray probe scheme for performing picosecond-resolution X-ray diffraction at the 1W2B wiggler beamline at Beijing Synchrotron Radiation Facility is reported. With the hybrid fill pattern in top-up mode, a pixel array X-ray detector was optimized to gate out the signal from the singlet bunch with interval 85 ns from the bunch train. The singlet pulse intensity is ∼2.5 × 106 photons pulse−1 at 10 keV. The laser pulse is synchronized to this singlet bunch at a 1 kHz repetition rate. A polycapillary X-ray lens was used for secondary focusing to obtain a 72 µm...
Source: Journal of Synchrotron Radiation - April 13, 2016 Category: Physics Authors: Sun, D.-R.Xu, G.-L.Zhang, B.-B.Du, X.-Y.Wang, H.Li, Q.-J.Zhou, Y.-F.Li, Z.-J.Zhang, Y.He, J.Yue, J.-H.Lei, G.Tao, Y. Tags: laser pump/X-ray probe ultrafast X-ray diffraction photo-induced strain beamlines Source Type: research

XAS spectroelectrochemistry: reliable measurement of X-ray absorption spectra from redox manipulated solutions at room temperature
The design and operation of a low-volume spectroelectrochemical cell for X-ray absorption spectroscopy (XAS) of solutions at room temperature is described. Fluorescence XAS measurements are obtained from samples contained in the void space of a 50 µL reticulated vitreous carbon (sponge) working electrode. Both rapid electrosynthesis and control of the effects of photoreduction are achieved by control over the flow properties of the solution through the working electrode, where a good balance between the rate of consumption of sample and the minimization of decomposition was obtained by pulsing the flow of the solut...
Source: Journal of Synchrotron Radiation - April 13, 2016 Category: Physics Authors: Best, S.P.Levina, A.Glover, C.Johannessen, B.Kappen, P.Lay, P.A. Tags: XAS XANES spectroelectrochemistry metalloproteins trioxalatoferrate(III) research papers Source Type: research